WO2015098559A1

WO2015098559A1 - Decoding device, decoding method, encoding device, and encoding method

Info

Publication number: WO2015098559A1
Application number: PCT/JP2014/082920
Authority: WO
Inventors: 佐藤　数史
Original assignee: ソニー株式会社
Priority date: 2013-12-27
Filing date: 2014-12-12
Publication date: 2015-07-02
Also published as: JP2015128205A

Abstract

This disclosure pertains to a decoding device, a decoding method, an encoding device, and an encoding method that make it possible to increase encoding efficiency when the image being encoded is increased or reduced in size. A reference-image buffer increases or reduces the size of a reference image on the basis of a value (log2_expanding_factor) that indicates the factor by which to increase or reduce the size of said reference image relative to an inter-encoded image. A generation unit uses the reference image, the size of which has been increased or reduced, to generate a prediction image. The inter-encoded image is decoded using said prediction image. This disclosure can be applied, for example, to a High Efficiency Video Coding (HEVC) decoding device or the like.

Description

Decoding device, decoding method, and encoding device and encoding method

The present disclosure relates to a decoding apparatus and a decoding method, and an encoding apparatus and an encoding method, and in particular, a decoding apparatus capable of improving encoding efficiency when an image to be encoded is enlarged or reduced, and The present invention relates to a decoding method, an encoding device, and an encoding method.

In recent years, devices based on MPEG (Moving Picture Experts Group phase) such as MPEG (Moving Experts Group phase) that compresses by orthogonal transformation such as discrete cosine transformation and motion compensation using redundancy unique to image information, And the reception of information in general households.

In particular, the MPEG2 (ISO / IEC 13818-2) system is defined as a general-purpose image encoding system. MPEG2 is a standard that covers both interlaced scanning images and progressive scanning images, as well as standard resolution images and high-definition images. MPEG2 is currently widely used in a wide range of applications for professional and consumer applications. By using the MPEG2 system, for example, a code amount of 4 to 8 Mbps is assigned for a standard resolution interlaced scan image having 720 × 480 pixels, and 18 to 22 MBps is assigned for a high resolution interlaced scan image having 1920 × 1088 pixels. Therefore, it is possible to realize a high compression rate and good image quality.

MPEG2 was mainly intended for high-quality encoding suitable for broadcasting, but it did not support encoding methods with a lower code amount (bit rate) than MPEG1, that is, a higher compression rate. With the widespread use of mobile terminals, the need for such an encoding system is expected to increase in the future, and the MPEG4 encoding system has been standardized accordingly. Regarding the MPEG4 image coding system, the standard was approved as an international standard in December 1998 as ISO / IEC 449 14496-2.

Furthermore, in recent years, for the purpose of image coding for the initial video conference, The standardization of 26L (ITU-T Q6 / 16 標準 VCEG) is in progress. H. 26L is known to realize higher encoding efficiency, although a larger amount of computation is required for encoding and decoding than encoding methods such as MPEG2 and MPEG4.

In recent years, as part of MPEG4 activities, Based on 26L, H. Standardization to achieve higher coding efficiency by incorporating functions that are not supported by 26L was done as Joint Model of Enhanced-Compression Video Coding. This standardization was implemented in March 2003 by H.C. It was internationally standardized under the names of H.264 and MPEG-4® Part 10 (AVC (Advanced Video Coding)).

In addition, as an extension, encoding tools necessary for business such as RGB, 4: 2: 2 and 4: 4: 4 color difference signal formats, 8 × 8DCT (Discrete Cosine Transform) specified by MPEG2, Standardization of FRExt (Fidelity Range Extension) including quantization matrix was completed in February 2005. As a result, the AVC system has become an encoding system that can well express film noise included in movies, and has been used for a wide range of applications such as BD (Blu-ray (registered trademark) Disc).

However, these days, we want to compress images with a resolution of about 4000 x 2000 pixels, which is four times that of high-definition images, or to deliver high-definition images in environments with limited transmission capacity such as the Internet. Needs are growing. For this reason, in the VCEG (Video Coding Expert Group) under the ITU-T umbrella, studies on improving coding efficiency are continuing.

Currently, with the aim of further improving the coding efficiency compared to AVC, ITUHEVC (High Efficiency Video Coding) by JCTVC (Joint Collaboration Team-Video Coding), a joint standardization organization of ITU-T and ISO / IEC. The standardization of the encoding method called is being advanced. As of December 2013, Non-Patent Document 1 has been issued as Draft.

The HEVC inter-prediction process is based on a translation model similar to MPEG-2 and AVC, and the encoding efficiency when the image to be encoded is enlarged or reduced cannot be improved.

The present disclosure has been made in view of such a situation, and is intended to improve encoding efficiency when an image to be encoded is enlarged or reduced.

The decoding device according to the first aspect of the present disclosure includes an enlargement / reduction unit that enlarges or reduces the reference image based on enlargement / reduction rate information indicating a rate of enlargement or reduction of the reference image with respect to the inter-coded image, and the enlargement / reduction unit. A generating unit that generates a predicted image using the reference image enlarged or reduced by the reducing unit; and a decoding unit that decodes the inter-coded image using the predicted image generated by the generating unit. It is a decoding device.

The decoding method according to the first aspect of the present disclosure corresponds to the decoding device according to the first aspect of the present disclosure.

In the first aspect of the present disclosure, the reference image is enlarged or reduced based on the enlargement / reduction rate information indicating the enlargement / reduction rate of the reference image with respect to the inter-coded image, and the reference image is enlarged or reduced. Is used to generate a predicted image, and the inter-coded image is decoded using the predicted image.

The encoding device according to the second aspect of the present disclosure includes an enlargement / reduction unit that enlarges or reduces the reference image based on enlargement / reduction rate information indicating a rate of enlargement or reduction of the reference image with respect to the image to be encoded; A generation unit that generates a prediction image using the reference image enlarged or reduced by the enlargement / reduction unit; and the encoding target image is encoded using the prediction image generated by the generation unit; An encoding device comprising: an encoding unit that generates encoded data; and a transmission unit that transmits the encoded data generated by the encoding unit and the enlargement / reduction ratio information.

The encoding method according to the second aspect of the present disclosure corresponds to the encoding device according to the second aspect of the present disclosure.

In the second aspect of the present disclosure, the reference image is enlarged or reduced based on the enlargement / reduction rate information indicating the enlargement / reduction rate of the reference image with respect to the encoding target image, and the reference is enlarged or reduced. A predicted image is generated using an image, the encoded image is generated using the predicted image, the encoded data is generated, and the encoded data and the enlargement / reduction ratio information are transmitted. .

The decoding device according to the first aspect and the encoding device according to the second aspect can be realized by causing a computer to execute a program.

In order to realize the decoding device of the first aspect and the encoding device of the second aspect, a program to be executed by a computer is transmitted through a transmission medium or recorded on a recording medium, Can be provided.

The decoding device of the first aspect and the encoding device of the second aspect may be independent devices or may be internal blocks constituting one device.

The network is a mechanism in which at least two devices are connected and information can be transmitted from one device to another device. The devices that communicate via the network may be independent devices, or may be internal blocks that constitute one device.

According to the first aspect of the present disclosure, the encoded stream can be decoded. Further, according to the first aspect of the present disclosure, it is possible to decode an encoded stream that is encoded so as to improve encoding efficiency when an image to be encoded is enlarged or reduced.

According to the second aspect of the present disclosure, an image can be encoded. Also, according to the second aspect of the present disclosure, it is possible to improve the encoding efficiency when the encoding target image is enlarged or reduced.

It should be noted that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a block diagram which shows the structural example of 1st Embodiment of the encoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the encoding part of FIG. It is a figure explaining CU. FIG. 3 is a block diagram illustrating a configuration example of a motion prediction / compensation unit in FIG. 2. It is a figure explaining PU of inter prediction. It is a figure explaining the interpolation filter process with respect to a luminance signal. It is a figure explaining the filter coefficient of the interpolation filter process with respect to a luminance signal. It is a figure explaining the interpolation filter process with respect to a color difference signal. It is a figure explaining the filter coefficient of the interpolation filter process with respect to a color difference signal. It is a figure explaining the read-out process in the reference image buffer of FIG. It is a figure explaining the read-out process in the reference image buffer of FIG. It is a figure which shows the example of peripheral PU in merge mode. It is a figure which shows the example of the syntax of mvd_coding of PU. It is a flowchart explaining the stream production | generation process of the encoding apparatus of FIG. FIG. 15 is a flowchart for describing details of the encoding process of FIG. 14. FIG. FIG. 15 is a flowchart for describing details of the encoding process of FIG. 14. FIG. 16 is a flowchart for explaining details of motion prediction / compensation processing in FIG. 15. It is a block diagram which shows the structural example of 1st Embodiment of the decoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the decoding part of FIG. FIG. 20 is a block diagram illustrating a configuration example of a motion compensation unit in FIG. 19. It is a flowchart explaining the image generation process of the decoding apparatus of FIG. It is a flowchart explaining the detail of the decoding process of FIG. It is a flowchart explaining the detail of the motion compensation process of FIG. It is a figure explaining the calculation method of the expansion / contraction rate information for every reference direction. It is a block diagram which shows the structural example of the encoding part of 2nd Embodiment of the encoding apparatus to which this indication is applied. FIG. 26 is a block diagram illustrating a configuration example of a motion prediction / compensation unit in FIG. 25. It is a flowchart explaining the encoding process of the encoding part of FIG. It is a flowchart explaining the encoding process of the encoding part of FIG. It is a flowchart explaining the detail of the motion prediction and compensation process of FIG. It is a block diagram which shows the structural example of the decoding part of 2nd Embodiment of the decoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the motion compensation part of FIG. It is a flowchart explaining the decoding process of the decoding part of FIG. FIG. 33 is a flowchart for describing details of a motion compensation process of FIG. 32. FIG. It is a block diagram which shows the structural example of the hardware of a computer. It is a figure which shows the example of a multiview image encoding system. It is a figure which shows the structural example of the multiview image coding apparatus to which this indication is applied. It is a figure which shows the structural example of the multiview image decoding apparatus to which this indication is applied. It is a figure which shows the example of a hierarchy image coding system. It is a figure explaining the example of spatial scalable encoding. It is a figure explaining the example of temporal scalable encoding. It is a figure explaining the example of the scalable encoding of a signal noise ratio. It is a figure which shows the structural example of the hierarchy image coding apparatus to which this indication is applied. It is a figure which shows the structural example of the hierarchy image decoding apparatus to which this indication is applied. It is a figure which shows the example of schematic structure of the television apparatus to which this indication is applied. It is a figure which shows the schematic structural example of the mobile telephone to which this indication is applied. It is a figure which shows the schematic structural example of the recording / reproducing apparatus to which this indication is applied. It is a figure which shows the schematic structural example of the imaging device to which this indication is applied. It is a block diagram which shows an example of scalable encoding utilization. It is a block diagram which shows the other example of scalable encoding utilization. It is a block diagram which shows the further another example of scalable encoding utilization. 2 illustrates an example of a schematic configuration of a video set to which the present disclosure is applied. 2 illustrates an example of a schematic configuration of a video processor to which the present disclosure is applied. The other example of the schematic structure of the video processor to which this indication is applied is shown.

<First embodiment>
(Configuration Example of First Embodiment of Encoding Device)
FIG. 1 is a block diagram illustrating a configuration example of a first embodiment of an encoding device to which the present disclosure is applied.

The encoding apparatus 10 in FIG. 1 includes a setting unit 11, an encoding unit 12, and a transmission unit 13, and encodes an image by a method according to the HEVC method.

Specifically, the setting unit 11 of the encoding device 10 sets parameter sets such as SPS (Sequence Parameter Set), PPS (Picture Parameter Set), VUI (Video Usability Information), SEI (Supplemental Enhancement Information). The setting unit 11 supplies the set parameter set to the encoding unit 12.

The frame unit image is input to the encoding unit 12. The encoding unit 12 encodes the input image using the HEVC method. The encoding unit 12 generates an encoded stream from the encoded data obtained as a result of encoding and the parameter set supplied from the setting unit 11, and supplies the encoded stream to the transmission unit 13.

The transmission unit 13 transmits the encoded stream supplied from the encoding unit 12 to a decoding device to be described later.

(Configuration example of encoding unit)
FIG. 2 is a block diagram illustrating a configuration example of the encoding unit 12 of FIG.

2 includes an A / D conversion unit 31, a screen rearrangement buffer 32, a calculation unit 33, an orthogonal transformation unit 34, a quantization unit 35, a lossless encoding unit 36, an accumulation buffer 37, a generation unit 38, An inverse quantization unit 39, an inverse orthogonal transform unit 40, and an addition unit 41 are included. The encoding unit 12 includes a deblocking filter 42, an adaptive offset filter 43, an adaptive loop filter 44, a frame memory 45, a switch 46, an intra prediction unit 47, a motion prediction / compensation unit 48, a determination unit 49, and a prediction image selection unit. 50 and a rate control unit 51.

The A / D conversion unit 31 of the encoding unit 12 performs A / D conversion on the frame-by-frame image input as an encoding target. The A / D conversion unit 31 outputs an image, which is a digital signal after conversion, to the screen rearrangement buffer 32 for storage.

The screen rearrangement buffer 32 rearranges the stored frame-by-frame images in the order for encoding according to the GOP structure. The screen rearrangement buffer 32 outputs the rearranged image to the calculation unit 33, the intra prediction unit 47, and the motion prediction / compensation unit 48.

The calculation unit 33 functions as an encoding unit, and performs encoding by subtracting the predicted image supplied from the predicted image selection unit 50 from the image supplied from the screen rearrangement buffer 32. The computing unit 33 outputs the resulting image to the orthogonal transform unit 34 as residual information. When the predicted image is not supplied from the predicted image selection unit 50, the calculation unit 33 outputs the image generated from the screen rearrangement buffer 32 to the orthogonal transform unit 34 as residual information as it is.

The orthogonal transform unit 34 orthogonally transforms the residual information from the calculation unit 33 in units of TU (transform unit). The orthogonal transform unit 34 supplies an orthogonal transform coefficient obtained as a result of the orthogonal transform to the quantization unit 35.

The quantization unit 35 performs quantization on the orthogonal transform coefficient supplied from the orthogonal transform unit 34. The quantization unit 35 supplies the quantized orthogonal transform coefficient to the lossless encoding unit 36.

The lossless encoding unit 36 acquires the intra prediction mode information indicating the optimal intra prediction mode from the intra prediction unit 47. In addition, the lossless encoding unit 36 encodes the inter prediction mode information indicating the optimal inter prediction mode, the motion vector information regarding the motion vector, the reference image specifying information for specifying the reference image, and the scaling rate information indicating the scaling rate. Is obtained from the motion prediction / compensation unit 48. The enlargement / reduction rate is a rate of enlargement or reduction of the reference image with respect to the image to be encoded, and is the same in the horizontal direction and the vertical direction here.

Also, the lossless encoding unit 36 acquires offset filter information related to the offset filter from the adaptive offset filter 43 and acquires filter coefficients from the adaptive loop filter 44.

The lossless encoding unit 36 performs variable-length coding (for example, CAVLC (Context-Adaptive Variable Length Coding)) and arithmetic coding (for example, for the quantized orthogonal transform coefficient supplied from the quantization unit 35. , CABAC (Context-Adaptive Binary Arithmetic Coding) etc.).

The lossless encoding unit 36 also relates to encoding intra prediction mode information or inter prediction mode information, motion vector information, reference image specifying information, encoded scaling information, offset filter information, and filter coefficients. Lossless encoding is performed as encoded information. The lossless encoding unit 36 supplies the encoding information and the orthogonal transform coefficient, which have been losslessly encoded, to the accumulation buffer 37 as encoded data and accumulates them. Note that the losslessly encoded encoding information may be added to the encoded data as a header portion such as a slice header.

The accumulation buffer 37 temporarily stores the encoded data supplied from the lossless encoding unit 36. The accumulation buffer 37 supplies the stored encoded data to the generation unit 38.

The generating unit 38 generates an encoded stream from the parameter set supplied from the setting unit 11 in FIG. 1 and the encoded data supplied from the accumulation buffer 37, and supplies the encoded stream to the transmission unit 13 in FIG.

The quantized orthogonal transform coefficient output from the quantization unit 35 is also input to the inverse quantization unit 39. The inverse quantization unit 39 performs inverse quantization on the orthogonal transform coefficient quantized by the quantization unit 35 by a method corresponding to the quantization method in the quantization unit 35. The inverse quantization unit 39 supplies the orthogonal transform coefficient obtained as a result of the inverse quantization to the inverse orthogonal transform unit 40.

The inverse orthogonal transform unit 40 performs inverse orthogonal transform on the orthogonal transform coefficient supplied from the inverse quantization unit 39 by a method corresponding to the orthogonal transform method in the orthogonal transform unit 34 in units of TUs. The inverse orthogonal transform unit 40 supplies the residual information obtained as a result to the addition unit 41.

The addition unit 41 adds the residual information supplied from the inverse orthogonal transform unit 40 and the prediction image supplied from the prediction image selection unit 50, and performs decoding locally. In addition, when a prediction image is not supplied from the prediction image selection part 50, the addition part 41 makes the residual information supplied from the inverse orthogonal transformation part 40 the image decoded locally. The adder 41 supplies the locally decoded image to the deblock filter 42 and the frame memory 45.

The deblocking filter 42 performs deblocking filter processing for removing block distortion on the locally decoded image supplied from the adding unit 41, and supplies the resulting image to the adaptive offset filter 43.

The adaptive offset filter 43 performs an adaptive offset filter (SAO (Sample adaptive offset)) process that mainly removes ringing on the image after the deblock filter process by the deblock filter 42.

Specifically, the adaptive offset filter 43 determines the type of adaptive offset filter processing for each LCU (Largest Coding Unit) which is the maximum coding unit, and obtains an offset used in the adaptive offset filter processing. The adaptive offset filter 43 performs the determined type of adaptive offset filter processing on the image after the deblocking filter processing using the obtained offset.

The adaptive offset filter 43 supplies the image after the adaptive offset filter processing to the adaptive loop filter 44. Further, the adaptive offset filter 43 supplies information indicating the type and offset of the adaptive offset filter processing performed to the lossless encoding unit 36 as offset filter information.

The adaptive loop filter 44 is constituted by, for example, a two-dimensional Wiener filter. The adaptive loop filter 44 performs an adaptive loop filter (ALF (Adaptive Loop Filter)) process on the image after the adaptive offset filter process supplied from the adaptive offset filter 43, for example, for each LCU.

Specifically, the adaptive loop filter 44 is configured so that the residual of the original image that is the image output from the screen rearrangement buffer 32 and the image after the adaptive loop filter processing is minimized for each LCU. A filter coefficient used in the processing is calculated. Then, the adaptive loop filter 44 performs adaptive loop filter processing for each LCU using the calculated filter coefficient on the image after the adaptive offset filter processing.

The adaptive loop filter 44 supplies the image after the adaptive loop filter processing to the frame memory 45. The adaptive loop filter 44 supplies the filter coefficient used for the adaptive loop filter process to the lossless encoding unit 36.

Note that here, the adaptive loop filter processing is performed for each LCU, but the processing unit of the adaptive loop filter processing is not limited to the LCU. However, the processing can be efficiently performed by combining the processing units of the adaptive offset filter 43 and the adaptive loop filter 44.

The frame memory 45 stores the image supplied from the adaptive loop filter 44 and the image supplied from the adder 41. Pixels adjacent to a PU (Prediction Unit) in an image that has not been subjected to filter processing accumulated in the frame memory 45 are supplied to the intra prediction unit 47 via the switch 46 as peripheral pixels. On the other hand, the filtered image stored in the frame memory 45 is output to the motion prediction / compensation unit 48 via the switch 46 as a reference image.

The intra prediction unit 47 performs intra prediction processing for all candidate intra prediction modes using peripheral pixels read from the frame memory 45 via the switch 46 in units of PUs.

Further, the intra prediction unit 47 calculates cost function values for all candidate intra prediction modes based on the image read from the screen rearrangement buffer 32 and the prediction image generated as a result of the intra prediction process. (Details will be described later). Then, the intra prediction unit 47 determines the intra prediction mode that minimizes the cost function value as the optimal intra prediction mode.

The intra prediction unit 47 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 50. The intra prediction unit 47 supplies the intra prediction mode information to the lossless encoding unit 36 when the prediction image selection unit 50 is notified of the selection of the prediction image generated in the optimal intra prediction mode.

Note that the cost function value is also called RD (Rate Distortion) cost. It is calculated based on a method of High Complexity mode or Low Complexity mode as defined by JM (Joint Model) which is reference software in the H.264 / AVC format. H. Reference software in the H.264 / AVC format is published at http://iphome.hhi.de/suehring/tml/index.htm.

Specifically, when the High Complexity 採用 mode is employed as a cost function value calculation method, all candidate prediction modes are temporarily decoded until the cost function represented by the following equation (1) A value is calculated for each prediction mode.

D is the difference (distortion) between the original image and the decoded image, R is the generated code amount including even the coefficient of orthogonal transformation, and λ is the Lagrange undetermined multiplier given as a function of the quantization parameter QP.

On the other hand, when Low Complexity mode is adopted as a cost function value calculation method, prediction image generation and code amount calculation of encoding information are performed for all candidate prediction modes. A cost function Cost (Mode) expressed by Equation (2) is calculated for each prediction mode.

D is the difference (distortion) between the original image and the predicted image, Header_Bit is the code amount of the encoding information, and QPtoQuant is a function given as a function of the quantization parameter QP.

In the Low Complexity mode, it is only necessary to generate a prediction image for all prediction modes, and it is not necessary to generate a decoded image.

The motion prediction / compensation unit 48 performs motion prediction / compensation processing for each PU based on the enlargement / reduction ratio, candidate inter prediction mode, motion vector, and reference image supplied from the determination unit 49. Specifically, the motion prediction / compensation unit 48 reads candidate reference images from the frame memory 45 via the switch 46. The motion prediction / compensation unit 48 increases the resolution of the reference image by performing an interpolation filter process on the reference image.

In addition, the motion prediction / compensation unit 48 performs compensation processing on the reference image with high resolution based on the candidate inter prediction mode, the motion vector with fractional pixel accuracy, and the enlargement / reduction ratio, and generates a prediction image. . The inter prediction mode is a mode representing a PU size and a motion vector coding mode. The motion vector coding mode includes a merge mode, an AMVP (Advanced Motion Vector Prediction) mode, and the like.

The merge mode is a mode in which motion vectors of a processing target PU are generated using motion vectors of temporally and spatially neighboring PUs (hereinafter referred to as neighboring PUs) of the processing target PU, and no motion vector information is transmitted. It is. Note that temporal motion vectors of peripheral PUs may not be used for generating motion vectors in merge mode. In this case, information (emporal_mvp_enabled_flag) indicating whether the temporal motion vector of the peripheral PU is not used for generating the motion vector in the merge mode may be set in the SPS or the slice header.

Also, the AMVP mode is a mode in which the difference between the motion vector of the peripheral PU and the motion vector of the processing target PU is transmitted as motion vector information. A motion vector encoding mode is a merge mode, and a block in which orthogonal transform coefficients are not transmitted is a skip mode block (skip macro).

Further, the motion prediction / compensation unit 48 uses the cost function value for the combination of the inter prediction mode, the motion vector, the enlargement / reduction ratio, and the reference image based on the image and the predicted image supplied from the screen rearrangement buffer 32. Is calculated. The motion prediction / compensation unit 48 determines the inter prediction mode that minimizes the cost function value as the optimal inter prediction mode. In addition, the motion prediction / compensation unit 48 determines the motion vector, the enlargement / reduction ratio, and the reference image that minimize the cost function value as the optimum motion vector, enlargement / reduction ratio, and reference image. Then, the motion prediction / compensation unit 48 supplies the prediction image in the optimal inter prediction mode and the cost function value to the prediction image selection unit 50.

Further, when the prediction image selection unit 50 is notified of selection of a prediction image generated in the optimal inter prediction mode, the motion prediction / compensation unit 48 receives inter prediction mode information, motion vector information of an optimal motion vector, The reference image specifying information of the reference image and the encoded enlargement / reduction rate information of the enlargement / reduction rate are output to the lossless encoding unit 36.

The determination unit 49 supplies the candidate enlargement / reduction ratio to the motion prediction / compensation unit 48 in units of PUs. In the present embodiment, the enlargement / reduction ratio is 2 ^r (r is an integer) that is common in the horizontal direction and the vertical direction, and the enlargement / reduction ratio information represents r.

Based on the cost function values supplied from the intra prediction unit 47 and the motion prediction / compensation unit 48, the predicted image selection unit 50 has a smaller cost function value corresponding to one of the optimal intra prediction mode and the optimal inter prediction mode. Are determined as the optimum prediction mode. Then, the predicted image selection unit 50 supplies the predicted image in the optimal prediction mode to the calculation unit 33 and the addition unit 41. Further, the predicted image selection unit 50 notifies the intra prediction unit 47 or the motion prediction / compensation unit 48 of selection of the predicted image in the optimal prediction mode.

The rate control unit 51 controls the quantization operation rate of the quantization unit 35 based on the encoded data stored in the storage buffer 37 so that overflow or underflow does not occur.

(Description of coding unit)
FIG. 3 is a diagram for explaining Coding Unit (CU), which is a coding unit in the HEVC scheme.

Since the HEVC system also targets images with large image frames such as UHD (Ultra High Definition) with 4000 pixels by 2000 pixels, it is not optimal to fix the encoding unit size to 16 pixels by 16 pixels. . Therefore, in the HEVC scheme, CU is defined as a coding unit. Details of this CU are described in Non-Patent Document 1.

CU plays the same role as a macroblock in the AVC method. Specifically, the CU is divided into PUs or TUs. The size of the TU is, for example, 4 × 4 pixels, 16 × 16 pixels, or 32 × 32 pixels.

However, the size of the CU is a square represented by a power-of-two pixel that is variable for each sequence. Specifically, the CU divides the LCU, which is the largest CU, into two in the horizontal direction and the vertical direction an arbitrary number of times so as not to be smaller than the SCU (Smallest Coding Unit) which is the smallest CU. Is set by That is, the size of an arbitrary hierarchy when the LCU is hierarchized so that the size of the upper hierarchy becomes 1/4 of the size of the lower hierarchy until the SCU becomes the SCU is the size of the CU.

For example, in FIG. 3, the LCU size is 128 and the SCU size is 8. Accordingly, the hierarchical depth (Depth) of the LCU is 0 to 4, and the hierarchical depth number is 5. That is, the number of divisions corresponding to the CU is one of 0 to 4.

Note that information specifying the LCU and SCU sizes is included in the SPS. Also, the number of divisions corresponding to the CU is specified by split_flag indicating whether or not to further divide each layer.

TU size can be specified using split_transform_flag, similar to CU split_flag. The maximum number of TU divisions at the time of inter prediction and intra prediction is specified by SPS as max_transform_hierarchy_depth_inter and max_transform_hierarchy_depth_intra, respectively.

Also, in this specification, CTU (Coding Tree Unit) is a unit including parameters for processing in CTB (Coding Tree Block) of LCU and its LCU base (level). Further, it is assumed that a CU constituting a CTU is a unit including CB (Coding Block) and a parameter for processing on the CU base (level).

(Configuration example of motion prediction / compensation unit)
FIG. 4 is a block diagram illustrating a configuration example of the motion prediction / compensation unit 48 of FIG.

The motion prediction / compensation unit 48 of FIG. 4 includes a linear interpolation filter 81, a reference image buffer 82, a low-pass filter 83, a generation unit 84, an input image buffer 85, a PU buffer 86, a calculation unit 87, a determination unit 88, and an information code. It is comprised by the conversion part 89.

The linear interpolation filter 81 of the motion prediction / compensation unit 48 is a two-dimensional linear interpolation filter. The linear interpolation filter 81 reads candidate reference images from the frame memory 45 via the switch 46. The linear interpolation filter 81 increases the resolution by performing an interpolation filter process on the read reference image. The linear interpolation filter 81 supplies the reference image with a high resolution to the reference image buffer 82.

The reference image buffer 82 holds the reference image supplied from the linear interpolation filter 81. The reference image buffer 82 functions as an enlargement / reduction unit, and reads out a stored reference image based on the enlargement / reduction rate supplied from the determination unit 49, so that the reference image enlarged or reduced at the enlargement / reduction rate can be obtained. Generated and supplied to the low-pass filter 83.

The low pass filter 83 is, for example, a 121 type low pass filter. The low-pass filter 83 performs low-pass filter processing on the reference image supplied from the reference image buffer 82 in the horizontal direction and the vertical direction. Thereby, the aliasing distortion of the reference image can be reduced. As a result, prediction accuracy is improved and coding efficiency is improved. The low pass filter 83 supplies the reference image after the low pass filter process to the generation unit 84.

The generation unit 84 performs a compensation process on the reference image supplied from the low-pass filter 83 based on a candidate motion vector in units of PUs, and generates a predicted image. The generation unit 84 supplies the predicted image to the calculation unit 87. The candidate motion vectors are a motion vector determined using a motion vector of a peripheral PU as a motion vector in the merge mode or AMVP mode, and a predetermined motion vector with fractional accuracy.

The input image buffer 85 holds the image supplied from the screen rearrangement buffer 32. The input image buffer 85 supplies the held image to the PU buffer 86 in units of PUs for each candidate inter prediction mode. The PU buffer 86 holds the PU unit image supplied from the input image buffer 85.

The calculation unit 87 reads an image in PU units from the PU buffer 86. The calculation unit 87 calculates a cost function value based on the read image and the predicted image for the combination of the inter prediction mode, the motion vector, the reference image, and the enlargement / reduction ratio. The calculation unit 87 supplies the cost function value, the corresponding inter prediction mode, the motion vector, the reference image, the combination of the enlargement / reduction ratio, and the prediction image to the determination unit 88.

The determination unit 88 determines the inter prediction mode when the cost function value supplied from the calculation unit 87 is the minimum as the optimal inter prediction mode, and determines the motion vector, reference image, and scaling ratio as the optimal motion vector and reference. Determine the image and the enlargement / reduction ratio. The determination unit 88 supplies the prediction image and the cost function value in the optimal inter prediction mode to the prediction image selection unit 50 in FIG. In addition, when the prediction image selection unit 50 notifies the selection of the prediction image generated in the optimal inter prediction mode, the determination unit 88 determines the optimal inter prediction mode, the optimal motion vector, and the reference image specifying information of the reference image. , And the enlargement / reduction ratio information of the enlargement / reduction ratio is supplied to the information encoding unit 89.

The information encoding unit 89 encodes the enlargement / reduction rate information supplied from the determination unit 88 by context modeling, and generates encoded enlargement / reduction rate information. Specifically, the information encoding unit 89 calculates a difference between the enlargement / reduction rate information of the processing target PU and the enlargement / reduction rate information of the PUs around the processing target PU as the encoded enlargement / reduction rate information.

Also, when the motion vector encoding mode is the merge mode, the information encoding unit 89 generates nothing as motion vector information. When the motion vector encoding mode is the AMVP mode, the information encoding unit 89 generates a difference between the motion vector of the processing target PU and the motion vector of the peripheral PU as motion vector information. On the other hand, when the motion vector encoding mode is not the merge mode or AMVP mode, the information encoding unit 89 generates information representing the motion vector of the PU to be processed as motion vector information.

The information encoding unit 89 supplies the inter prediction mode information, motion vector information, reference image specifying information, and encoded enlargement / reduction rate information to the lossless encoding unit 36 of FIG.

(Explanation of inter prediction PU)
FIG. 5 is a diagram illustrating inter prediction PU (motion compensation partition).

In FIG. 5, CU is assumed to be 2N × 2N pixels.

The PU of inter prediction is formed by dividing a CU symmetrically as shown in the upper part of FIG. 5 or asymmetrically dividing a CU as shown in the lower part of FIG.

Specifically, the PU of inter prediction may be a 2N × 2N pixel that is a CU itself, an N × 2N pixel that bisects a CU bilaterally, or a 2N × N pixel that bisects a CU vertically. it can. However, the inter prediction PU cannot be an N × N pixel obtained by dividing the CU into two vertically and horizontally symmetrically. Therefore, for example, when 16 × 16 pixels are used as an inter prediction PU, the CU needs to be 16 × 16 pixels instead of 32 × 32 pixels.

Also, the PU of inter prediction can be configured by asymmetric partitioning (AMP (asymmetric motion partition)). That is, the inter prediction PU is ½N × 2N pixels (Left) obtained by dividing the CU into two parts so that the left side is asymmetrically left or right, or ½N obtained by dividing the CU into two parts so that the right side is asymmetrically reduced. × 2N pixels (Right) can also be used. The inter prediction PU is a 2N × 1 / 2N pixel (Upper) obtained by dividing the CU into two parts so that the upper side is asymmetrical in the vertical direction, or 2N × 1 / 2N pixels (upper) obtained by dividing the CU into two parts so that the lower side is asymmetrical in the vertical direction A 1 / 2N pixel (Lower) can also be used.

Information (amp_enabled_flag) indicating whether or not the inter prediction PU is configured by asymmetrical division of the CU is set in the SPS.

Inter prediction mode, motion vector, reference image, enlargement / reduction ratio, etc. are set independently for each PU of inter prediction. In the HEVC scheme, the minimum size of the CU is 8 × 8 pixels, and the minimum size of the PU for inter prediction is 4 × 8 pixels or 8 × 4 pixels. In the HEVC scheme, the size of the inter prediction PU cannot be set to 4 × 4 pixels in order to reduce the memory bandwidth.

(Description of interpolation filter processing for luminance signal)
FIG. 6 is a diagram for explaining the interpolation filter processing for the luminance signal by the linear interpolation filter 81 of FIG.

In FIG. 6, a hatched square represents a reference image pixel (hereinafter referred to as a previous pixel) before the interpolation filter process, and a hatched square represents a reference after the interpolation filter process. It represents a pixel of an image (hereinafter referred to as a back pixel). The same applies to FIG. 8 described later.

The motion prediction / compensation unit 48 performs motion prediction / compensation processing of the luminance signal with 1/4 pixel accuracy. Therefore, the linear interpolation filter 81 performs an interpolation filter process in the horizontal direction and the vertical direction on the luminance signal of the reference image using an 8-tap or 7-tap two-dimensional linear interpolation adaptive filter. A pixel after an interval that is 1/4 of the interval between the previous pixels is generated.

For example, for a certain previous pixel A _0,0 , the previous pixel A _0,0 and the previous pixel A _1,0 and the previous pixel A _0,1 adjacent to the previous pixel A _0,0 The front pixel A _{0,0 and the} rear pixels a _{0,0 to} k _0,0 , n _0,0 , and p _{0,0 to} r ₀ at a 4 × 4 position with the position of A _0,0 as the upper left position _{, 0} is generated. Incidentally, the preceding pixel A _i, i of _j, the front pixel A _i, represents the horizontal position of the _j, j represents the position in the vertical direction. In addition, _{i of} the rear pixels a _{i, j to} k _{i, j} , n _{i, j} and p _{i, j to} r _{i, j} represents the horizontal position of the corresponding front pixel A _{i, j} , j Represents the position in the vertical direction.

The filter coefficients of an 8-tap or 7-tap two-dimensional linear interpolation adaptive filter are as shown in FIG. In other words, the index of the previous pixel closest to the subsequent pixel to be generated is set to 0, and the index of the pixel arranged in the direction with respect to the previous pixel of the pixel is increased in the order from the rear pixel to be generated, which is opposite to that direction. The index of the pixels lined up in the direction is made smaller in order from the next pixel to be generated.

At this time, each index i (i = -3, -2, -1, -1, The filter coefficients (hfilter [i]) of 8 taps for the pixels of 0,1,2,3,4) are -1,4, -11,40,40, -11,4, in ascending order of i. -1.

Further, a 7-tap filter coefficient (qfilter [i]) for the pixel of each index i when generating a subsequent pixel whose distance from the previous pixel closest to the direction of the interpolation filter processing is 1/4 of the interval of the previous pixel. ) Becomes -1,4, -10,58,17, -5,1 in ascending order of i.

Therefore, the rear pixels a _{0,0 to} d _0,0 , h _0,0 and n _0,0 are calculated by the following equation (3).

In equation (3), shift1 is a value obtained by subtracting 8 from the bit depth BitDepthy of the luminance signal of the image to be encoded.

Further, the rear pixels e _{0,0 to} g _0,0 , i _{0,0 to} k _0,0 and p _{0,0 to} r _0,0 are calculated by the following equation (4).

In equation (4), shift2 is a value obtained by subtracting 6 from the bit depth BitDepthy.

(Description of interpolation filter processing for color difference signal)
FIG. 8 is a diagram for explaining the interpolation filter processing for the color difference signal by the linear interpolation filter 81 of FIG.

The motion prediction / compensation unit 48 performs motion prediction / compensation processing of color difference signals with 1/8 pixel accuracy. Therefore, the linear interpolation filter 81 uses the 4-tap two-dimensional linear interpolation adaptive filter to perform the interpolation filter processing in the horizontal direction and the vertical direction on the color difference signal of the reference image, thereby Generate a pixel after the interval 1/8 of the interval.

For example, for a certain previous pixel B _0,0 , the previous pixel B _0,0 and the previous pixel B _1,0 and the previous pixel B _0,1 adjacent to the previous pixel B _0,0 The front pixel B _{0,0 and the} rear pixel ab _{0,0 to} ah _0,0 , ba _{0,0 to} bh _0,0 , ca _{0 at} the position of 8 × 8 with the position of B _{0,0 being} the upper left position _{0 to} ch _0,0 , da _{0,0 to} dh _0,0 , ea _{0,0 to} eh _0,0 , fa ₀ , _{0 to} fh _0,0 , ga ₀ , _{0 to} gh _0,0 , and ha _{0 , 0 to} hh _0,0 are generated.

Note that _{i of} the previous pixel B _{i, j} represents the horizontal position of the previous pixel A _{i, j} , and j represents the vertical position. Further, the rear pixels abi _{, j to} ah _{i, j} , ba _{i, j to} bh _{i, j} , ca _{i, j to} ch _{i, j} , da _{i, j to} dh _{i, j} , ea _{i, j to} eh _{i, j} , fa _{i, j to} fh _{i, j} , ga _{i, j to} gh _{i, j} , and _i of ha _{i, j to} hh _{i, j} are the horizontal direction of the corresponding previous pixel B _{i, j} Represents the position, and j represents the position in the vertical direction.

The filter coefficients of a 4-tap two-dimensional linear interpolation adaptive filter are as shown in FIG. That is, the index of the pixel closest to the subsequent pixel to be generated is set to 0, and the index of the pixel aligned in the direction with respect to the previous pixel of the pixel is increased in the order closer to the subsequent pixel to be generated, and the pixel aligned in the direction opposite to that direction Are made smaller in order from the next pixel to be generated.

At this time, each index i (i = -1,0,1,2) when generating a subsequent pixel whose distance to the previous pixel closest to the direction of the interpolation filter processing is 1/8 of the interval of the previous pixel The filter coefficients (filter1 [i]) for the pixel of −2 are −2, 58, 10, and −2 in order from the smallest i.

Also, the filter coefficient (filter2 [i]) for the pixel of each index i when generating a subsequent pixel whose distance from the previous pixel closest to the direction of the interpolation filter processing is 2/8 of the interval of the previous pixel is In order from the smallest i, -4, 54, 16, and -2. The filter coefficient (filter3 [i]) for each index i pixel when generating a subsequent pixel whose distance to the previous pixel closest to the direction of the interpolation filter processing is 3/8 of the previous pixel interval is In order from the smallest, -6, 46, 28, -4.

Furthermore, the filter coefficient (filter4 [i]) for each index i pixel when generating a subsequent pixel whose distance to the previous pixel closest to the direction of the interpolation filter processing is 4/8 of the interval of the previous pixel is In order from the smallest i, -4, 36, 36, -4.

Accordingly, the rear pixels ab _{0,0 to} ah _0,0 are calculated by the following equation (5).

In equation (5), shift1 is a value obtained by subtracting 8 from the bit depth BitDepthc of the color difference signal of the image to be encoded. The same applies to the equation (6) described later.

Further, the rear pixels ba _{0,0 to} ha _0,0 are calculated by the following equation (6).

Further, the rear pixels bX _{0,0 to} hX _0,0 (X = b, c, d, e, f, g, h) are calculated by the following equation (7).

In equation (7), shift2 is a value obtained by subtracting 6 from the bit depth BitDepthc.

輝度 Interpolation filter processing of luminance signal and chrominance signal is made to fit within 16-bit accuracy.

(Description of read processing in reference image buffer)
10 and 11 are diagrams for explaining the reading process in the reference image buffer 82 of FIG. In FIGS. 10 and 11, a circle represents a pixel.

As shown in FIG. 10, when the enlargement / reduction ratio information is a value smaller than 0, that is, when the enlargement / reduction ratio information represents the enlargement ratio, the reference image buffer 82 sets the enlargement / reduction ratio indicated by the enlargement / reduction ratio information. Based on this, the reference image 91 is enlarged, and an enlarged reference image 92 is generated.

For example, as shown in FIG. 10, when the enlargement / reduction ratio information is −1 and the size of the reference image 91 is 4 × 4 pixels, the reference image buffer 82 sets each pixel 91a of the reference image 91 as the pixel. Read out as 2 × 2 pixels 92a to 92d at positions corresponding to 91a. As a result, the reference image buffer 82 generates an enlarged reference image 92 of 8 × 8 pixels.

On the other hand, as shown in FIG. 11, when the enlargement / reduction ratio information is a value larger than 0, the reference image buffer 82 reduces the reference image 93 based on the enlargement / reduction ratio represented by the enlargement / reduction ratio information and The reference image 94 is generated.

For example, as shown in FIG. 11, when the enlargement / reduction ratio information is 1 and the size of the reference image 93 is 8 × 8 pixels, the reference image buffer 82 converts the reference image 93 into a block 93a of 2 × 2 pixels. To divide. The reference image buffer 82 selects one pixel 93b (upper left pixel in the example of FIG. 11) in each block 93a as a representative pixel. The reference image buffer 82 reads the pixel 93b of each block 93a as a pixel 94a at a position corresponding to the block 93a. Thereby, the reference image buffer 82 generates a reference image 94 after reduction of 4 × 4 pixels.

Note that the reference image buffer 82 may generate the pixel at the center of the block 93a by using the pixel in the block 93a instead of the pixel 93b selected as the representative pixel as the pixel 94a.

(Example of neighboring PUs in merge mode)
FIG. 12 is a diagram illustrating an example of peripheral PUs in the merge mode.

As shown in FIG. 12, the spatial peripheral PU candidates in the merge mode of the PU 101 to be processed include the PU 102 adjacent to the PU 101 in the left direction and the PU 103 adjacent in the lower left direction. Further, there are a PU 104 adjacent in the upper direction, a PU 105 adjacent in the upper right direction, and a PU 106 adjacent in the upper left direction.

As spatial peripheral PUs, one from each of the

available PUs

102 and 103 and the available PUs among the PUs 104 to 106 is selected according to the following priority order. Note that all of the PUs 102 to 106 that have the same motion vector are not available, except for one, in order to eliminate redundancy.

1. PU with the same reference image and prediction direction as the processing target PU 101
2. The PU 101 to be processed and the reference image are the same, but the PUs with different prediction directions
3. PU 101 to be processed is different from the reference image, but the prediction direction is the same PU
4). The PU to be processed differs from the reference image in the prediction direction.

When a spatial neighboring PU having the third or fourth priority is selected, the scaling process shown in the following equation (8) is performed on the motion vector of the neighboring PU, The motion vector is used to generate a motion vector of the processing target PU 101.

In Equation (8), mvLxA is a spatial motion vector of a peripheral PU. Tb and td are defined by the following equation (9).

According to Equation (9), td is the difference between the POC collocated on the PU 101 to be processed and the POC of the reference image of the PU 108. Also, tb is the difference between the processing target PU 101 and the reference image POC (Picture 処理 Order Count) of the PU 101. Note that the PU 108 that is collocated on the processing target PU 101 is a PU that is temporally different from the processing target PU 101 but has the same spatial position.

In addition, the temporally neighboring PU candidates in the merge mode of the processing target PU 101 are different from the processing target PU 101 in terms of time, but the right PU and the central PU 108 in the region 107 having the same spatial position and size. There is PU109 below.

When the PU 109 is available, the temporal peripheral PU is the PU 109. If the PU 109 is not available but the PU 108 is available, the temporally neighboring PU is set as the PU 108.

(Mvd_coding syntax example)
FIG. 13 is a diagram illustrating an example of the syntax of mvd_coding of a PU.

As shown in FIG. 13, the enlargement / reduction ratio information is set as log2_expanding_factor in mvd_coding.

(Description of processing of encoding device)
FIG. 14 is a flowchart illustrating a stream generation process of the encoding device 10 of FIG.

In step S11 of FIG. 14, the setting unit 11 of the encoding device 10 sets a parameter set. The setting unit 11 supplies the set parameter set to the encoding unit 12.

In step S12, the encoding unit 12 performs an encoding process for encoding an image of a frame unit input from the outside using the HEVC method. Details of the encoding process will be described with reference to FIGS. 15 and 16 to be described later.

In step S <b> 13, the generation unit 38 (FIG. 2) of the encoding unit 12 generates an encoded stream from the parameter set supplied from the setting unit 11 and the encoded data supplied from the accumulation buffer 37, and sends it to the transmission unit 13. Supply.

In step S14, the transmission unit 13 transmits the encoded stream supplied from the setting unit 11 to a decoding device to be described later, and ends the process.

15 and 16 are flowcharts illustrating details of the encoding process in step S12 of FIG.

In step S30 of FIG. 15, the A / D conversion unit 31 of the encoding unit 12 performs A / D conversion on the frame unit image input as the encoding target. The A / D conversion unit 31 outputs an image, which is a digital signal after conversion, to the screen rearrangement buffer 32 for storage.

In step S31, the screen rearrangement buffer 32 rearranges the images of the stored frames in the display order in the order for encoding according to the GOP structure. The screen rearrangement buffer 32 supplies the rearranged frame-unit images to the calculation unit 33, the intra prediction unit 47, and the motion prediction / compensation unit 48.

In step S32, the intra prediction unit 47 performs intra prediction processing for all candidate intra prediction modes in units of PUs. Further, the intra prediction unit 47 calculates cost function values for all candidate intra prediction modes based on the image read from the screen rearrangement buffer 32 and the prediction image generated as a result of the intra prediction process. Is calculated. Then, the intra prediction unit 47 determines the intra prediction mode that minimizes the cost function value as the optimal intra prediction mode. The intra prediction unit 47 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 50.

Also, the motion prediction / compensation unit 48 performs motion prediction / compensation processing in units of PUs based on candidate inter prediction modes, motion vectors, reference images, and enlargement / reduction ratios. Details of this motion prediction / compensation processing will be described with reference to FIG.

In step S <b> 33, the predicted image selection unit 50 has the cost function value of the optimal intra prediction mode and the optimal inter prediction mode that is the minimum based on the cost function values supplied from the intra prediction unit 47 and the motion prediction / compensation unit 48. Is determined as the optimum prediction mode. Then, the predicted image selection unit 50 supplies the predicted image in the optimal prediction mode to the calculation unit 33 and the addition unit 41.

In step S34, the predicted image selecting unit 50 determines whether or not the optimal prediction mode is the optimal inter prediction mode. When it is determined in step S34 that the optimal prediction mode is the optimal inter prediction mode, the predicted image selection unit 50 notifies the motion prediction / compensation unit 48 of the selection of the predicted image generated in the optimal inter prediction mode. Thereby, the determination unit 88 (FIG. 4) of the motion prediction / compensation unit 48 provides information about the optimal inter prediction mode, the optimal motion vector, the reference image specifying information of the reference image, and the enlargement / reduction rate information of the enlargement / reduction rate. This is supplied to the encoding unit 89.

In step S35, the information encoding unit 89 generates motion vector information according to the motion vector encoding mode. The information encoding unit 89 encodes the enlargement / reduction rate supplied from the determination unit 88 by context modeling, and generates encoded enlargement / reduction rate information.

In step S36, the information encoding unit 89 supplies the inter prediction mode information, the motion vector information, the reference image specifying information, and the encoded enlargement / reduction rate information to the lossless encoding unit 36, and the process proceeds to step S38.

On the other hand, when it is determined in step S34 that the optimal prediction mode is not the optimal inter prediction mode, that is, when the optimal prediction mode is the optimal intra prediction mode, the predicted image selection unit 50 performs the prediction generated in the optimal intra prediction mode. The intra prediction unit 47 is notified of the image selection. In step S37, the intra prediction unit 47 supplies the intra prediction mode information to the lossless encoding unit 36, and the process proceeds to step S38.

In step S38, the calculation unit 33 performs encoding by subtracting the predicted image supplied from the predicted image selection unit 50 from the image supplied from the screen rearrangement buffer 32. The computing unit 33 outputs the resulting image to the orthogonal transform unit 34 as residual information.

In step S39, the orthogonal transform unit 34 performs orthogonal transform on the residual information from the operation unit 33 in units of TUs, and supplies the resulting orthogonal transform coefficient to the quantization unit 35.

In step S40, the quantization unit 35 quantizes the orthogonal transform coefficient supplied from the orthogonal transform unit 34, and supplies the quantized orthogonal transform coefficient to the lossless encoding unit 36 and the inverse quantization unit 39.

In step S41 in FIG. 16, the inverse quantization unit 39 inversely quantizes the quantized orthogonal transform coefficient supplied from the quantization unit 35, and supplies the resulting orthogonal transform coefficient to the inverse orthogonal transform unit 40. .

In step S42, the inverse orthogonal transform unit 40 performs inverse orthogonal transform on the orthogonal transform coefficient supplied from the inverse quantization unit 39 in units of TUs, and supplies the residual information obtained as a result to the addition unit 41.

In step S43, the addition unit 41 adds the residual information supplied from the inverse orthogonal transform unit 40 and the prediction image supplied from the prediction image selection unit 50, and performs decoding locally. The adder 41 supplies the locally decoded image to the deblock filter 42 and the frame memory 45.

In step S44, the deblocking filter 42 performs a deblocking filter process on the locally decoded image supplied from the adding unit 41. The deblocking filter 42 supplies the resulting image to the adaptive offset filter 43.

In step S45, the adaptive offset filter 43 performs an adaptive offset filter process on the image supplied from the deblocking filter 42 for each LCU. The adaptive offset filter 43 supplies the resulting image to the adaptive loop filter 44. Further, the adaptive offset filter 43 supplies the offset filter information to the lossless encoding unit 36 for each LCU.

In step S46, the adaptive loop filter 44 performs an adaptive loop filter process on the image supplied from the adaptive offset filter 43 for each LCU. The adaptive loop filter 44 supplies the resulting image to the frame memory 45. The adaptive loop filter 44 supplies the filter coefficient used in the adaptive loop filter process to the lossless encoding unit 36.

In step S47, the frame memory 45 stores the image supplied from the adaptive loop filter 44 and the image supplied from the adder 41. Pixels adjacent to the PU in the image that has not been subjected to the filter processing accumulated in the frame memory 45 are supplied to the intra prediction unit 47 through the switch 46 as peripheral pixels. On the other hand, the filtered image stored in the frame memory 45 is output to the motion prediction / compensation unit 48 via the switch 46 as a reference image.

In step S48, the lossless encoding unit 36 encodes intra prediction mode information, inter prediction mode information, motion vector information, reference image specifying information, encoded enlargement / reduction ratio information, offset filter information, and filter coefficients. Lossless encoding as the conversion information.

In step S49, the lossless encoding unit 36 performs lossless encoding on the quantized orthogonal transform coefficient supplied from the quantization unit 35. Then, the lossless encoding unit 36 generates encoded data from the encoded information that has been losslessly encoded in the process of step S48 and the orthogonal transform coefficient that has been losslessly encoded, and supplies the encoded data to the accumulation buffer 37.

In step S50, the accumulation buffer 37 temporarily accumulates the encoded data supplied from the lossless encoding unit 36.

In step S51, the rate control unit 51 controls the rate of the quantization operation of the quantization unit 35 based on the encoded data stored in the storage buffer 37 so that overflow or underflow does not occur.

In step S52, the accumulation buffer 37 outputs the stored encoded data to the generation unit 38. And a process returns to step S12 of FIG. 14, and progresses to step S13. And a process returns to step S12 of FIG. 14, and progresses to step S13.

In the encoding processing of FIGS. 15 and 16, in order to simplify the description, the intra prediction processing and the motion prediction / compensation processing are always performed. Sometimes only.

FIG. 17 is a flowchart for explaining the details of the motion prediction / compensation process in step S32 of FIG. This motion prediction / compensation process is performed in units of PUs.

In step S71 of FIG. 17, the motion prediction / compensation unit 48 determines a candidate reference image that has not yet been determined as a reference image for the current process, as a reference image for the current process.

In step S72, the determination unit 49 determines the candidate enlargement / reduction ratio that has not yet been decided as the enlargement / reduction ratio of the current process as the enlargement / reduction ratio of the current process.

In step S <b> 73, the motion prediction / compensation unit 48 determines the PU size of the current process that has not yet been determined as the PU size of the current process among the PU sizes represented by the candidate inter prediction modes. To decide.

In step S74, the linear interpolation filter 81 (FIG. 4) of the motion prediction / compensation unit 48 reads the reference image determined in step S71 from the frame memory 45 via the switch 46.

In step S75, the linear interpolation filter 81 increases the resolution of the reference image by performing an interpolation filter process on the read reference image. The linear interpolation filter 81 supplies the reference image with high resolution to the reference image buffer 82 and holds it.

In step S76, the reference image buffer 82 reads the stored reference image based on the enlargement / reduction ratio supplied from the determination unit 49, thereby generating a reference image enlarged or reduced at the enlargement / reduction ratio, The low-pass filter 83 is supplied.

In step S77, the low-pass filter 83 performs a low-pass filter process on the reference image supplied from the reference image buffer 82 in the horizontal direction and the vertical direction.

In step S78, the input image buffer 85 reads out the PU having the size determined in step S73 from the images supplied and held from the screen rearranging buffer 32, and supplies the PU to the PU buffer 86 for holding.

In step S79, the generation unit 84 determines a candidate motion vector that has not yet been determined as the current processing target motion vector as the current processing target motion vector.

In step S80, the generation unit 84 performs compensation processing on the reference image supplied from the low-pass filter 83 based on the motion vector determined in step S79, and generates a predicted image. The generation unit 84 supplies the predicted image to the calculation unit 87.

In step S81, the calculation unit 87 reads an image in PU units from the PU buffer 86, and calculates a cost function value based on the image and the predicted image. The calculation unit 87 supplies the cost function value and the predicted image to the determination unit 88. The calculation unit 87 determines the reference image, the enlargement / reduction ratio, and the motion vector determined in steps S71, S72, and S79, and the motion vector encoding mode corresponding to the motion vector and the step S73. A combination of inter prediction modes representing the PU size is supplied to the determination unit 88.

In step S82, the motion prediction / compensation unit 48 determines whether or not the cost function value has been calculated for all candidate motion vectors, that is, all candidate motion vectors are determined to be motion vectors of the current process in step S79. Determine whether it was done.

If it is determined in step S82 that cost function values have not been calculated for all candidate motion vectors, the process returns to step S79. Then, the processes in steps S79 to S82 are repeated until it is determined that the cost function values have been calculated for all candidate motion vectors.

On the other hand, if it is determined in step S82 that cost function values have been calculated for all candidate motion vectors, the process proceeds to step S83. In step S83, the motion prediction / compensation unit 48 has calculated cost function values for all candidate PU sizes, that is, all candidate PU sizes in step S73 are the current processing PUs. Determine whether the size has been determined.

If it is determined in step S83 that cost function values have not been calculated for all candidate PU sizes, the process returns to step S73. Then, the processes of steps S73 to S83 are repeated until it is determined that the cost function values have been calculated for all candidate PU sizes.

On the other hand, if it is determined in step S83 that the cost function value has been calculated for all candidate PU sizes, the process proceeds to step S84. In step S84, the determination unit 49 determines whether or not the cost function value has been calculated for all of the candidate enlargement / reduction ratios, that is, all of the candidate enlargement / reduction ratios in step S72 are the enlargement / reduction ratios of the current process. Determine whether it was done.

If it is determined in step S84 that cost function values have not been calculated for all of the candidate enlargement / reduction ratios, the process returns to step S72. Then, the processes of steps S72 to S84 are repeated until it is determined that the cost function value has been calculated for all of the candidate enlargement / reduction ratios.

On the other hand, if it is determined in step S84 that the cost function values have been calculated for all of the candidate enlargement / reduction ratios, the process proceeds to step S85. In step S85, the motion prediction / compensation unit 48 determines whether or not the cost function value has been calculated for all candidate reference images, that is, all candidate reference images are determined as reference images for the current process in step S71. Determine whether it was done.

If it is determined in step S85 that the cost function value has not been calculated for all candidate reference images, the process returns to step S71. Then, the processes in steps S71 to S85 are repeated until it is determined that the cost function value has been calculated for all candidate reference images.

On the other hand, when it is determined in step S85 that the cost function value has been calculated for all candidate reference images, in step S86, the determination unit 88 determines that the cost function value supplied from the calculation unit 87 is minimum. The inter prediction mode is determined as the optimal inter prediction mode. Further, the determination unit 88 determines the motion vector, reference image, and enlargement / reduction ratio at the time when the cost function value is minimum as the optimum motion vector, reference image, and enlargement / reduction ratio.

In step S87, the determination unit 88 supplies the cost function value and the prediction image in the optimal inter prediction mode to the prediction image selection unit 50 in FIG.

As described above, the encoding device 10 enlarges or reduces the reference image based on the enlargement / reduction ratio information, and generates a predicted image using the enlarged or reduced reference image. Therefore, the prediction accuracy when the image to be encoded is enlarged or reduced is improved, and the encoding efficiency is improved.

(Configuration example of first embodiment of decoding device)
FIG. 18 is a block diagram illustrating a configuration example of a first embodiment of a decoding device to which the present disclosure is applied, which decodes an encoded stream transmitted from the encoding device 10 in FIG. 1.

18 is configured by a receiving unit 111, an extracting unit 112, and a decoding unit 113.

The receiving unit 111 of the decoding device 110 receives the encoded stream transmitted from the encoding device 10 in FIG. 1 and supplies it to the extracting unit 112.

The extraction unit 112 extracts a parameter set and encoded data from the encoded stream supplied from the receiving unit 111 and supplies the extracted parameter set and encoded data to the decoding unit 113.

The decoding unit 113 decodes the encoded data supplied from the extraction unit 112 using the HEVC method. At this time, the decoding unit 113 also refers to the parameter set supplied from the extraction unit 112 as necessary. The decoding unit 113 outputs an image obtained as a result of decoding.

(Configuration example of decoding unit)
FIG. 19 is a block diagram illustrating a configuration example of the decoding unit 113 in FIG.

19 includes an accumulation buffer 131, a lossless decoding unit 132, an inverse quantization unit 133, an inverse orthogonal transform unit 134, an addition unit 135, a deblock filter 136, an adaptive offset filter 137, an adaptive loop filter 138, and a screen. A rearrangement buffer 139 is provided. The decoding unit 113 includes a D / A conversion unit 140, a frame memory 141, a switch 142, an intra prediction unit 143, a motion compensation unit 144, an information decoding unit 145, and a switch 146.

The accumulation buffer 131 of the decoding unit 113 receives and accumulates the encoded data from the extraction unit 112 of FIG. The accumulation buffer 131 supplies the accumulated encoded data to the lossless decoding unit 132.

The lossless decoding unit 132 performs lossless decoding such as variable length decoding and arithmetic decoding corresponding to the lossless encoding of the lossless encoding unit 36 of FIG. 2 on the encoded data from the accumulation buffer 131, A quantized orthogonal transform coefficient and encoding information are obtained. The lossless decoding unit 132 supplies the quantized orthogonal transform coefficient to the inverse quantization unit 133. Further, the lossless decoding unit 132 supplies intra prediction mode information as encoded information to the intra prediction unit 143. The lossless decoding unit 132 supplies inter prediction mode information and reference image specifying information to the motion compensation unit 144, and supplies inter prediction mode information, motion vector information, and encoded enlargement / reduction rate information to the information decoding unit 145.

Further, the lossless decoding unit 132 supplies intra prediction mode information or inter prediction mode information as encoded information to the switch 146. The lossless decoding unit 132 supplies offset filter information as encoded information to the adaptive offset filter 137. The lossless decoding unit 132 supplies filter coefficients as encoded information to the adaptive loop filter 138.

The inverse quantization unit 133, the inverse orthogonal transform unit 134, the addition unit 135, the deblock filter 136, the adaptive offset filter 137, the adaptive loop filter 138, the frame memory 141, the switch 142, the intra prediction unit 143, and the motion compensation unit 144 Inverse quantization unit 39, inverse orthogonal transform unit 40, addition unit 41, deblock filter 42, adaptive offset filter 43, adaptive loop filter 44, frame memory 45, switch 46, intra prediction unit 47, and motion prediction / The same processing as that of the compensation unit 48 is performed, whereby the image is decoded.

Specifically, the inverse quantization unit 133 inversely quantizes the quantized orthogonal transform coefficient from the lossless decoding unit 132 and supplies the orthogonal transform coefficient obtained as a result to the inverse orthogonal transform unit 134.

The inverse orthogonal transform unit 134 performs inverse orthogonal transform on the orthogonal transform coefficient from the inverse quantization unit 133 in units of TUs. The inverse orthogonal transform unit 134 supplies residual information obtained as a result of the inverse orthogonal transform to the addition unit 135.

The addition unit 135 functions as a decoding unit, and performs decoding by adding the residual information supplied from the inverse orthogonal transform unit 134 and the prediction image supplied from the switch 146. The adding unit 135 supplies an image obtained as a result of decoding to the deblocking filter 136 and the frame memory 141.

When the predicted image is not supplied from the switch 146, the adding unit 135 sets the image that is the residual information supplied from the inverse orthogonal transform unit 134 as an image obtained as a result of decoding in the deblocking filter 136 and the frame memory 141. Supply.

The deblocking filter 136 performs a deblocking filter process on the image supplied from the adding unit 135, and supplies the resulting image to the adaptive offset filter 137.

The adaptive offset filter 137 performs adaptive offset filter processing of the type represented by the offset filter information on the image after the deblocking filter processing using the offset represented by the offset filter information from the lossless decoding unit 132 for each LCU. . The adaptive offset filter 137 supplies the image after the adaptive offset filter processing to the adaptive loop filter 138.

The adaptive loop filter 138 performs an adaptive loop filter process for each LCU on the image supplied from the adaptive offset filter 137 using the filter coefficient supplied from the lossless decoding unit 132. The adaptive loop filter 138 supplies the resulting image to the frame memory 141 and the screen rearrangement buffer 139.

The screen rearrangement buffer 139 stores the image supplied from the adaptive loop filter 138 in units of frames. The screen rearrangement buffer 139 rearranges the stored frame-by-frame images for encoding in the original display order and supplies them to the D / A conversion unit 140.

The D / A conversion unit 140 performs D / A conversion on the frame-based image supplied from the screen rearrangement buffer 139 and outputs it.

The frame memory 141 stores the image supplied from the adaptive loop filter 138 and the image supplied from the adding unit 135. Pixels adjacent to the PU in the image that has not been subjected to filter processing accumulated in the frame memory 141 are supplied to the intra prediction unit 143 via the switch 142 as peripheral pixels. On the other hand, the filtered image stored in the frame memory 141 is supplied to the motion compensation unit 144 via the switch 142 as a reference image.

The intra prediction unit 143 uses the peripheral pixels read from the frame memory 141 via the switch 142 in units of PUs, and performs intra prediction in the optimal intra prediction mode indicated by the intra prediction mode information supplied from the lossless decoding unit 132. Process. The intra prediction unit 143 supplies the prediction image generated as a result to the switch 146.

The motion compensation unit 144 is based on the enlargement / reduction rate information and the motion vector supplied from the information decoding unit 145 and the inter prediction mode information and the reference image specifying information supplied from the lossless decoding unit 132 in units of PUs. Perform compensation processing. Specifically, the motion compensation unit 144 reads the reference image specified by the reference image specifying information supplied from the lossless decoding unit 132 from the frame memory 141 via the switch 142. The motion compensation unit 144 increases the resolution of the reference image by performing an interpolation filter process on the reference image. The motion compensation unit 144 uses the reference image with high resolution based on the enlargement / reduction rate information and the motion vector supplied from the information decoding unit 145 and the PU size represented by the inter prediction mode information to generate a prediction image. Generate. The motion compensation unit 144 supplies the predicted image to the switch 146.

The information decoding unit 145 decodes the encoded enlargement / reduction rate information supplied from the lossless decoding unit 132. Specifically, the information decoding unit 145 adds the enlargement / reduction rate information of the PUs around the processing target PU and the difference that is the encoded enlargement / reduction rate information to generate the enlargement / reduction rate information of the processing target PU. To do.

In addition, when the motion vector encoding mode represented by the inter prediction information supplied from the lossless decoding unit 132 is the merge mode, the information decoding unit 145 uses the motion vector of the peripheral PU to calculate the motion vector of the PU to be processed. Generate. On the other hand, when the motion vector encoding mode is the AMVP mode, the information decoding unit 145 adds the motion vector of the PU around the PU to be processed and the difference between the motion vectors as the motion vector information, and A motion vector of the PU is generated.

In addition, when the motion vector encoding mode is not the merge mode or the AMVP mode, the information decoding unit 145 generates a motion vector that is motion vector information as a motion vector of the PU to be processed. The information decoding unit 145 supplies the enlargement / reduction ratio information and the motion vector to the motion compensation unit 144.

When the intra prediction mode information is supplied from the lossless decoding unit 132, the switch 146 supplies the prediction image supplied from the intra prediction unit 143 to the addition unit 135. On the other hand, when the inter prediction mode information is supplied from the lossless decoding unit 132, the switch 146 supplies the prediction image supplied from the motion compensation unit 144 to the adding unit 135.

(Configuration example of motion compensation unit)
FIG. 20 is a block diagram illustrating a configuration example of the motion compensation unit 144 of FIG.

20 includes a linear interpolation filter 161, a reference image buffer 162, a low-pass filter 163, and a generation unit 164.

The linear interpolation filter 161 of the motion compensation unit 144 is a two-dimensional linear interpolation filter. The linear interpolation filter 161 reads the reference image specified by the reference image specifying information supplied from the lossless decoding unit 132 in FIG. 19 from the frame memory 141 via the switch 142. The linear interpolation filter 161 increases the resolution by performing an interpolation filter process on the read reference image. The linear interpolation filter 161 supplies the reference image with a high resolution to the reference image buffer 162.

The reference image buffer 162 holds the reference image supplied from the linear interpolation filter 161. The reference image buffer 162 functions as an enlargement / reduction unit, and reads the held reference image based on the enlargement / reduction rate information supplied from the information decoding unit 145, similarly to the reference image buffer 82 of FIG. Thereby, a reference image enlarged or reduced at the enlargement / reduction ratio represented by the enlargement / reduction ratio information is generated. The reference image buffer 162 supplies the reference image to the low pass filter 163.

The low pass filter 163 is, for example, a 121 type low pass filter. The low-pass filter 163 performs low-pass filter processing on the reference image supplied from the reference image buffer 162 in the horizontal direction and the vertical direction in the same manner as the low-pass filter 83. The low pass filter 163 supplies the reference image after the low pass filter process to the generation unit 164.

The generation unit 164 is a reference supplied from the low-pass filter 163 in units of PUs based on the PU size represented by the inter prediction mode supplied from the lossless decoding unit 132 and the motion vector supplied from the information decoding unit 145. Compensate the image. The generation unit 164 supplies the predicted image generated as a result to the switch 146 in FIG.

(Description of processing of decoding device)
FIG. 21 is a flowchart illustrating the image generation processing of the decoding device 110 in FIG.

21, the reception unit 111 of the decoding device 110 receives the encoded stream transmitted from the encoding device 10 of FIG. 1 and supplies the encoded stream to the extraction unit 112.

In step S112, the extraction unit 112 extracts encoded data and a parameter set from the encoded stream supplied from the reception unit 111, and supplies the extracted encoded data and parameter set to the decoding unit 113.

In step S113, the decoding unit 113 performs a decoding process for decoding the encoded data supplied from the extraction unit 112 by a method according to the HEVC method, using the parameter set supplied from the extraction unit 112 as necessary. Details of this decoding process will be described with reference to FIG. Then, the process ends.

FIG. 22 is a flowchart for explaining the details of the decoding process in step S113 of FIG.

22, the accumulation buffer 131 (FIG. 19) of the decoding unit 113 receives the encoded data in units of frames from the extraction unit 112 of FIG. 18 and accumulates it. The accumulation buffer 131 supplies the accumulated encoded data to the lossless decoding unit 132.

In step S131, the lossless decoding unit 132 losslessly decodes the encoded data from the accumulation buffer 131 to obtain quantized orthogonal transform coefficients and encoded information. The lossless decoding unit 132 supplies the quantized orthogonal transform coefficient to the inverse quantization unit 133.

Also, the lossless decoding unit 132 supplies intra prediction mode information as encoded information to the intra prediction unit 143. The lossless decoding unit 132 supplies inter prediction mode information and reference image specifying information to the motion compensation unit 144, and supplies inter prediction mode information, motion vector information, and encoded enlargement / reduction rate information to the information decoding unit 145.

Further, the lossless decoding unit 132 supplies intra prediction mode information or inter prediction mode information as encoded information to the switch 146. The lossless decoding unit 132 supplies offset filter information as encoded information to the adaptive offset filter 137 and supplies filter coefficients to the adaptive loop filter 138.

In step S132, the inverse quantization unit 133 performs inverse quantization on the quantized orthogonal transform coefficient from the lossless decoding unit 132, and supplies the resulting orthogonal transform coefficient to the inverse orthogonal transform unit 134.

In step S133, the inverse orthogonal transform unit 134 performs inverse orthogonal transform on the orthogonal transform coefficient from the inverse quantization unit 133, and supplies the residual information obtained as a result to the addition unit 135.

In step S134, the motion compensation unit 144 determines whether or not the inter prediction mode information is supplied from the lossless decoding unit 132. If it is determined in step S134 that the inter prediction mode information has been supplied, the process proceeds to step S135.

In step S135, the information decoding unit 145 generates a motion vector from the motion vector information in units of PUs according to the motion vector encoding mode represented by the inter prediction information supplied from the lossless decoding unit 132. Also, the information decoding unit 145 decodes the encoded enlargement / reduction rate information supplied from the lossless decoding unit 132 in units of PUs, and generates enlargement / reduction rate information. The information decoding unit 145 supplies the enlargement / reduction ratio information and the motion vector to the motion compensation unit 144.

In step S136, the motion compensation unit 144 is based on the enlargement / reduction ratio and motion vector supplied from the information decoding unit 145, and the inter prediction mode information and reference image specifying information supplied from the lossless decoding unit 132 in units of PUs. Then, motion compensation processing is performed. Details of this motion compensation processing will be described with reference to FIG. After the process of step S136, the process proceeds to step S138.

On the other hand, if it is determined in step S134 that the inter prediction mode information is not supplied, that is, if the intra prediction mode information is supplied to the intra prediction unit 143, the process proceeds to step S137.

In step S137, the intra prediction unit 143 performs intra prediction processing in the intra prediction mode indicated by the intra prediction mode information using the peripheral pixels read from the frame memory 141 via the switch 142 in units of PUs. The intra prediction unit 143 supplies the prediction image generated as a result of the intra prediction process to the addition unit 135 via the switch 146, and the process proceeds to step S138.

In step S138, the addition unit 135 performs decoding locally by adding the residual information supplied from the inverse orthogonal transform unit 134 and the prediction image supplied from the switch 146. The adding unit 135 supplies an image obtained as a result of decoding to the deblocking filter 136 and the frame memory 141.

In step S139, the deblock filter 136 performs a deblock filter process on the image supplied from the adder 135 to remove block distortion. The deblocking filter 136 supplies the resulting image to the adaptive offset filter 137.

In step S140, the adaptive offset filter 137 performs adaptive offset filter processing for each LCU on the image from the deblocking filter 136 based on the offset filter information supplied from the lossless decoding unit 132. The adaptive offset filter 137 supplies the image after the adaptive offset filter processing to the adaptive loop filter 138.

In step S141, the adaptive loop filter 138 performs adaptive loop filter processing for each LCU on the image supplied from the adaptive offset filter 137 using the filter coefficient supplied from the lossless decoding unit 132. The adaptive loop filter 138 supplies the resulting image to the frame memory 141 and the screen rearrangement buffer 139.

In step S142, the frame memory 141 stores the image supplied from the adder 135 and the image supplied from the adaptive loop filter 138. Pixels adjacent to the PU in the image that has not been subjected to filter processing accumulated in the frame memory 141 are supplied to the intra prediction unit 143 via the switch 142 as peripheral pixels. On the other hand, the filtered image stored in the frame memory 141 is supplied to the motion compensation unit 144 via the switch 142 as a reference image.

In step S143, the screen rearrangement buffer 139 stores the image supplied from the adaptive loop filter 138 in units of frames, and rearranges the stored frame-by-frame images for encoding in the original display order. To the D / A converter 140.

In step S144, the D / A conversion unit 140 performs D / A conversion on the frame-based image supplied from the screen rearrangement buffer 139, and outputs it. Then, the process returns to step S113 in FIG. 21 and ends.

FIG. 23 is a flowchart for explaining the details of the motion compensation processing in step S136 of FIG. This motion compensation process is performed in units of PUs.

23, the linear interpolation filter 161 (FIG. 20) of the motion compensation unit 144 acquires reference image specifying information from the lossless decoding unit 132. In step S151, the linear interpolation filter 161 reads the reference image specified by the reference image specifying information from the frame memory 141 via the switch 142.

In step S152, the linear interpolation filter 161 increases the resolution of the reference image by performing an interpolation filter process on the read reference image. The linear interpolation filter 161 supplies the high-resolution reference image to the reference image buffer 162 and holds it.

In step S153, the reference image buffer 162 acquires the enlargement / reduction ratio information from the information decoding unit 145. In step S154, the reference image buffer 162 reads the reference image held based on the enlargement / reduction ratio information, thereby generating a reference image enlarged or reduced at the enlargement / reduction ratio represented by the enlargement / reduction ratio. The reference image buffer 162 supplies the reference image to the low pass filter 163.

In step S155, the low-pass filter 163 performs low-pass filter processing on the reference image supplied from the reference image buffer 162 in the horizontal direction and the vertical direction. The low pass filter 163 supplies the reference image after the low pass filter process to the generation unit 164.

In step S156, the generation unit 164 acquires the inter prediction mode from the lossless decoding unit 132. In step S157, the generation unit 164 acquires a motion vector from the information decoding unit 145.

In step S158, the generation unit 164 performs compensation processing on the reference image supplied from the low-pass filter 163 based on the PU size and the motion vector represented by the inter prediction mode information. The generation unit 164 supplies the predicted image generated as a result to the switch 146 in FIG.

As described above, the decoding apparatus 110 enlarges or reduces the reference image based on the enlargement / reduction ratio information, and generates a predicted image using the enlarged or reduced reference image. Therefore, it is possible to decode the encoded stream that is encoded by the encoding device 10 so as to improve the encoding efficiency when the image to be encoded is enlarged or reduced.

Note that it is possible not to perform low-pass filter processing on the reference image. The presence / absence of low-pass filter processing may be controlled in units of PUs or CUs. In this case, for example, the low pass filter process can be performed only when the size of the PU or CU is smaller than a predetermined size, that is, when the image quality deterioration due to aliasing distortion is significant. In this case, as necessary, the encoding device 10 transmits information indicating whether low-pass filter processing has been performed to the decoding device 110 in units of PUs or CUs, and the decoding device 110 performs the processing based on the information. Low-pass filter processing is performed on the reference image.

Also, the enlargement and reduction of the reference image may be turned on and off in units of pictures. In this case, information (enabled_flag) indicating whether to enlarge or reduce the reference image is set in the PPS, and when enabled_flag is 1 indicating that the reference image is enlarged or reduced, an enlargement / reduction rate is set. When enabled_flag is 1, the reference image is enlarged or reduced at the enlargement / reduction ratio set in PPS. When it is 0, the reference image is not enlarged or reduced. Similarly, the enlargement and reduction of the reference image may be turned on / off in units of slices. In this case, enabled_flag is set in the slice header, and when enabled_flag is 1, the enlargement / reduction ratio is set. Further, the enlargement and reduction of the reference image may be turned on / off in units of CUs.

Further, the encoded enlargement / reduction ratio information may be transmitted in units of PUs or may be transmitted in units of CUs.

Also, when the motion vector encoding mode is the merge mode, the enlargement / reduction rate of the peripheral PU that is the reference destination of the motion vector may be determined as the optimum enlargement / reduction rate of the PU that is the reference source processing target. In this case, the encoding device 10 does not transmit the encoding enlargement / reduction rate information, and the decoding device 110 sets the enlargement / reduction rate of the peripheral PU as the enlargement / reduction rate of the processing target PU in the merge mode.

Furthermore, in the above description, the enlargement / reduction ratio is the same in the horizontal direction and the vertical direction, but may be different.

Also, the enlargement / reduction ratio may be set independently for each reference direction. The reference direction includes a forward direction in which the encoding order of the reference image is before the encoding target image, and a backward direction in which the encoding order of the reference image is after the encoding target image.

When the enlargement / reduction ratio is set independently for each reference direction, the encoding apparatus 10 may transmit the encoded enlargement / reduction ratio information for each reference direction, or the forward direction and the rear direction may be transmitted. Only one of the encoded enlargement / reduction ratio information may be transmitted.

When the encoding device 10 transmits only the encoding enlargement / reduction rate information of one of the reference directions, the decoding device 110 temporally compares one reference image, the image to be decoded, and the other reference image. Based on the distance and one enlargement / reduction ratio, the other enlargement / reduction ratio is calculated.

Specifically, for example, as illustrated in FIG. 24, when the reference direction is the forward direction, the enlargement / reduction rate information is -1, and the encoded enlargement / reduction rate information of the enlargement / reduction rate information is transmitted. The decoding apparatus 110 calculates a temporal distance between the encoding target image 181 and the forward reference image 182. Also, the decoding device 110 calculates the temporal distance between the encoding target image 181 and the backward reference image 183. The temporal distance is a difference between POC (Picture (Order Count).

24, the temporal distance between the encoding target image 181 and the reference image 182 and the temporal distance between the encoding target image 181 and the reference image 183 are the same. Therefore, the decoding apparatus 110 generates 1 times the value obtained by reversing the sign of the enlargement / reduction rate information when the reference direction is the forward direction, that is, 1 as the enlargement / reduction rate information when the reference direction is the backward direction. To do.

<Second Embodiment>
(Configuration example of the second embodiment of the encoding device)
The configuration of the encoding apparatus according to the second embodiment to which the present disclosure is applied is configured similarly to the encoding device 10 of FIG. 1 except for the encoding unit 12. Therefore, only the encoding unit will be described below.

FIG. 25 is a block diagram illustrating a configuration example of the encoding unit of the second embodiment of the encoding device to which the present disclosure is applied.

25, the same reference numerals are given to the same components as those in FIG. The overlapping description will be omitted as appropriate.

The configuration of the encoding unit 200 in FIG. 25 is that the determination unit 49 is not provided, the enlargement / reduction unit 201 is provided, and the frame memory 45, the motion prediction / compensation unit 48, and the lossless encoding unit 36 are used. 2 is different from the configuration of the encoding unit 12 in that a frame memory 202, a motion prediction / compensation unit 203, and a lossless encoding unit 204 are provided. The encoding unit 200 holds a plurality of decoded images having different enlargement / reduction ratios for each decoded image in the frame memory 202, and assigns different reference image specifying information to the decoded images.

Specifically, the enlargement / reduction unit 201 of the encoding unit 200 enlarges or reduces the image supplied from the adaptive loop filter 44 as a reference image candidate based on the enlargement / reduction rate correspondence information set in the PPS, The frame memory 202 is supplied. The enlargement / reduction rate correspondence information is information representing the correspondence between reference image candidate reference image specification information and the reference image candidate enlargement / reduction rate specified by the reference image specification information. This enlargement / reduction ratio may be the same in the horizontal direction and the vertical direction, or may be different.

The frame memory 202 stores the image supplied from the enlargement / reduction unit 201 and the image supplied from the addition unit 41. Pixels adjacent to the PU in the image that has not been subjected to the filter processing accumulated in the frame memory 202 are supplied as peripheral pixels to the intra prediction unit 47 via the switch 46. On the other hand, the filtered image stored in the frame memory 202 is output to the motion prediction / compensation unit 203 via the switch 46 as a reference image.

The motion prediction / compensation unit 203 performs a motion prediction / compensation process based on the candidate inter prediction mode, the motion vector, and the reference image for each PU. Specifically, the motion prediction / compensation unit 203 reads candidate reference images from the frame memory 202 via the switch 46. The motion prediction / compensation unit 203 increases the resolution of the reference image by performing an interpolation filter process on the reference image.

Also, the motion prediction / compensation unit 203 performs compensation processing on the reference image that has been increased in resolution based on the candidate inter prediction mode and the motion vector with fractional pixel accuracy, and generates a predicted image. The motion prediction / compensation unit 203 calculates a cost function value for the combination of the inter prediction mode, the motion vector, and the reference image based on the image and the predicted image supplied from the screen rearrangement buffer 32. The motion prediction / compensation unit 203 determines the inter prediction mode that minimizes the cost function value as the optimal inter prediction mode. In addition, the motion prediction / compensation unit 203 determines the motion vector and reference image that minimize the cost function value as the optimal motion vector and reference image. Then, the motion prediction / compensation unit 203 supplies the predicted image and the cost function value in the optimal inter prediction mode to the predicted image selection unit 50.

In addition, when the prediction image selection unit 50 is notified of the selection of the prediction image generated in the optimal inter prediction mode, the motion prediction / compensation unit 203 receives the inter prediction mode information, the motion vector information of the optimal motion vector, and The reference image specifying information of the reference image is output to the lossless encoding unit 204.

The lossless encoding unit 204 performs lossless encoding on the quantized orthogonal transform coefficient supplied from the quantization unit 35. Further, the lossless encoding unit 204 performs lossless encoding on intra prediction mode information, inter prediction mode information, motion vector information, reference image specifying information, offset filter information, and filter coefficients as encoded information. The lossless encoding unit 204 supplies the encoded information and the orthogonal transform coefficient, which are losslessly encoded, to the accumulation buffer 37 as encoded data, and accumulates them. Note that the losslessly encoded encoding information may be added to the encoded data as a header portion such as a slice header.

(Configuration example of motion prediction / compensation unit)
FIG. 26 is a block diagram illustrating a configuration example of the motion prediction / compensation unit 203 of FIG.

26, the same components as those in FIG. 4 are denoted by the same reference numerals. The overlapping description will be omitted as appropriate.

The configuration of the motion prediction / compensation unit 203 in FIG. 26 is that a low-pass filter 83 is not provided, and a reference image is used instead of the reference image buffer 82, the generation unit 84, the calculation unit 87, the determination unit 88, and the information encoding unit 89. 4 is different from the configuration of the motion prediction / compensation unit 48 in that a buffer 221, a generation unit 222, a calculation unit 223, a determination unit 224, and an information encoding unit 225 are provided.

The reference image buffer 221 holds the reference image supplied from the linear interpolation filter 81.

The generating unit 222 performs a compensation process on the reference image held in the reference image buffer 221 based on a candidate motion vector for each PU, and generates a predicted image. The generation unit 222 supplies the predicted image to the calculation unit 223. Candidate motion vectors are the same as in the first embodiment.

The calculation unit 223 reads the PU unit image from the PU buffer 86. The calculation unit 223 calculates a cost function value for the combination of the inter prediction mode, the motion vector, and the reference image based on the read image and the predicted image. The calculation unit 223 supplies the cost function value, the corresponding inter prediction mode, the motion vector, the combination of the reference image, and the prediction image to the determination unit 224.

The determination unit 224 determines the inter prediction mode when the cost function value supplied from the calculation unit 223 is minimum as the optimal inter prediction mode, and determines the motion vector and the reference image as the optimal motion vector and the reference image. The determination unit 224 supplies the prediction image and the cost function value in the optimal inter prediction mode to the prediction image selection unit 50 in FIG. In addition, when the prediction image selection unit 50 notifies the selection of the prediction image generated in the optimal inter prediction mode, the determination unit 224 determines the optimal inter prediction mode, the optimal motion vector, and the reference image specifying information of the reference image. Is supplied to the information encoding unit 225.

The information encoding unit 225 generates the motion vector information of the PU to be processed, similar to the information encoding unit 89 in FIG. The information encoding unit 225 supplies the optimal inter prediction mode, motion vector information, and reference image specifying information to the lossless encoding unit 204 in FIG.

(Description of processing of encoding unit)
27 and 28 are flowcharts illustrating the encoding process of the encoding unit 200 in FIG.

27 is the same as the process of steps S30 and S31 of FIG. 15, and thus the description thereof is omitted.

In step S172, the intra prediction unit 47 performs intra prediction processing for all candidate intra prediction modes in units of PUs. Further, the intra prediction unit 47 calculates cost function values for all candidate intra prediction modes based on the image read from the screen rearrangement buffer 32 and the prediction image generated as a result of the intra prediction process. Is calculated. Then, the intra prediction unit 47 determines the intra prediction mode that minimizes the cost function value as the optimal intra prediction mode. The intra prediction unit 47 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 50.

Also, the motion prediction / compensation unit 203 performs a motion prediction / compensation process based on the candidate inter prediction mode, motion vector, and reference image in units of PUs. Details of the motion prediction / compensation processing will be described with reference to FIG. 29 described later.

Since the processing in steps S173 and S174 is the same as the processing in steps S33 and S34 in FIG.

In step S175, the information encoding unit 225 (FIG. 26) of the motion prediction / compensation unit 203 generates motion vector information in accordance with the motion vector encoding mode. In step S176, the information encoding unit 225 supplies the inter prediction mode information, the motion vector information, and the reference image specifying information to the lossless encoding unit 204, and the process proceeds to step S178.

Since the processing of steps S177 to S186 is the same as the processing of steps S37 to S46 of FIGS. 15 and 16, description thereof will be omitted.

In step S187, the enlargement / reduction unit 201 enlarges or reduces the image supplied from the adaptive loop filter 44 as a reference image candidate based on the enlargement / reduction rate correspondence information set in the PPS. Specifically, the enlargement / reduction unit 201 sets all the enlargement / reduction rates associated with a plurality of pieces of reference image specifying information for specifying images supplied from the adaptive loop filter 44 in the enlargement / reduction rate correspondence information. The image scaling rate.

When the enlargement / reduction ratio is an enlargement ratio, the enlargement / reduction unit 201 generates one pixel in the image supplied from the adaptive loop filter 44 as a plurality of pixels constituting the enlarged image. In addition, when the enlargement / reduction ratio is the reduction ratio, the enlargement / reduction unit 201 selects one pixel in an area composed of a plurality of pixels of the image supplied from the adaptive loop filter 44 after the reduction corresponding to the area. Generated as image pixels. Then, the enlargement / reduction unit 201 supplies the enlarged image or the reduced image to the frame memory 202.

In step S188, the frame memory 202 accumulates the image supplied from the enlargement / reduction unit 201 and the image supplied from the addition unit 41. Pixels adjacent to the PU in the image that has not been subjected to the filter processing accumulated in the frame memory 202 are supplied as peripheral pixels to the intra prediction unit 47 via the switch 46. On the other hand, the filtered image stored in the frame memory 202 is output to the motion prediction / compensation unit 203 via the switch 46 as a reference image.

The processing in steps S189 through S193 is the same as the processing in steps S48 through S52 in FIG.

FIG. 29 is a flowchart for explaining the details of the motion prediction / compensation processing in step S172 of FIG.

29 is the same as the processes in steps S71, S73 to S75, and S78 to S80 in FIG.

In step S208, the calculation unit 223 reads the PU unit image from the PU buffer 86, and calculates the cost function value based on the image and the predicted image. The calculation unit 223 supplies the cost function value and the predicted image to the determination unit 224. The calculation unit 223 also performs inter prediction that represents the reference image and motion vector determined in steps S201 and S206, the motion vector encoding mode corresponding to the motion vector, and the PU size determined in step S202. The combination of modes is supplied to the determination unit 224.

Since the processing of steps S209 to S211 is the same as the processing of steps S82, S83, and S85, description thereof will be omitted.

In step S212, the determination unit 224 determines the inter prediction mode when the cost function value supplied from the calculation unit 223 is minimum as the optimal inter prediction mode. In addition, the determination unit 224 determines the motion vector and reference image when the cost function value is minimum as the optimal motion vector and reference image.

In step S213, the determination unit 224 supplies the cost function value and the prediction image in the optimal inter prediction mode to the prediction image selection unit 50 in FIG.

As described above, the encoding unit 200 enlarges or reduces a decoded image that is a reference image candidate based on the enlargement / reduction ratio correspondence information, and uses the enlarged or reduced decoded image as a reference image to generate a predicted image. Generate. Therefore, the prediction accuracy when the image to be encoded is enlarged or reduced is improved, and the encoding efficiency is improved.

(Configuration example of second embodiment of decoding device)
Since the configuration of the second embodiment of the decoding device to which the present disclosure is applied is the same as that of the decoding device 110 in FIG. 18 except for the decoding unit 113, only the decoding unit will be described below.

FIG. 30 is a block diagram illustrating a configuration example of a decoding unit according to the second embodiment of the decoding device to which the present disclosure is applied.

30, the same reference numerals are given to the same components as those in FIG. 19. The overlapping description will be omitted as appropriate.

30 includes a lossless decoding unit 132, an information decoding unit 145, a frame memory 141, and a motion compensation unit 144 instead of the lossless decoding unit 241, the information decoding unit 242, the frame memory 244, and the motion compensation unit 245. Is different from the configuration of the decoding unit 113 in FIG. 19 in that the point is provided and the point that the enlargement / reduction unit 243 is newly provided.

Specifically, the lossless decoding unit 241 performs quantized orthogonality by performing lossless decoding corresponding to the lossless encoding of the lossless encoding unit 204 of FIG. 25 on the encoded data from the accumulation buffer 131. Obtain transform coefficients and encoding information. The lossless decoding unit 241 supplies the quantized orthogonal transform coefficient to the inverse quantization unit 133. In addition, the lossless decoding unit 241 supplies intra prediction mode information as encoded information to the intra prediction unit 143. The lossless decoding unit 241 supplies the inter prediction mode information and the reference image specifying information to the motion compensation unit 245, and supplies the inter prediction mode information and the motion vector information to the information decoding unit 242.

Similarly to the information decoding unit 145 in FIG. 19, the information decoding unit 242 generates a motion vector of the PU to be processed based on the motion vector encoding mode represented by the inter prediction information supplied from the lossless decoding unit 241. . The information decoding unit 242 supplies the generated motion vector to the motion compensation unit 245.

The enlargement / reduction unit 243 enlarges or reduces the image supplied from the adaptive loop filter 138 based on the enlargement / reduction rate correspondence information included in the PPS supplied from the extraction unit 112 in FIG. 18 and supplies the image to the frame memory 244. .

The frame memory 244 stores the image supplied from the enlargement / reduction unit 243 and the image supplied from the addition unit 135. Pixels adjacent to the PU in the image that has not been subjected to filter processing accumulated in the frame memory 244 are supplied to the intra prediction unit 143 via the switch 142 as peripheral pixels. On the other hand, the filtered image stored in the frame memory 244 is supplied as a reference image to the motion compensation unit 245 via the switch 142.

The motion compensation unit 245 performs motion compensation processing in units of PUs based on the motion vector supplied from the information decoding unit 242 and the inter prediction mode information and reference image specifying information supplied from the lossless decoding unit 241. Specifically, the motion compensation unit 245 reads the reference image specified by the reference image specifying information supplied from the lossless decoding unit 241 from the frame memory 244 via the switch 142. The motion compensation unit 245 increases the resolution of the reference image by performing an interpolation filter process on the reference image. Based on the motion vector supplied from the information decoding unit 242 and the size of the PU represented by the inter prediction mode information, the motion compensation unit 245 generates a prediction image using the reference image that has been increased in resolution. The motion compensation unit 245 supplies the predicted image to the switch 146.

(Configuration example of motion compensation unit)
FIG. 31 is a block diagram illustrating a configuration example of the motion compensation unit 245 of FIG.

31, the same reference numerals are given to the same components as those in FIG. 20. The overlapping description will be omitted as appropriate.

31 differs from the configuration of the motion compensation unit 144 in FIG. 20 in that a reference image buffer 261 is provided instead of the reference image buffer 162. The configuration of the motion compensation unit 245 in FIG.

The reference image buffer 261 of the motion compensation unit 245 holds the reference image supplied from the linear interpolation filter 161. This reference image is subjected to compensation processing in the generation unit 164.

(Description of processing of the decoding unit)
FIG. 32 is a flowchart illustrating the decoding process of the decoding unit 240 in FIG.

32, the accumulation buffer 131 of the decoding unit 240 receives and accumulates encoded data in units of frames from the extraction unit 112 of FIG. The accumulation buffer 131 supplies the accumulated encoded data to the lossless decoding unit 241.

In step S231, the lossless decoding unit 241 performs lossless decoding of the encoded data from the accumulation buffer 131, and obtains quantized orthogonal transform coefficients and encoded information. The lossless decoding unit 241 supplies the quantized orthogonal transform coefficient to the inverse quantization unit 133.

Also, the lossless decoding unit 241 supplies intra prediction mode information as encoded information to the intra prediction unit 143. The lossless decoding unit 241 supplies the inter prediction mode information and the reference image specifying information to the motion compensation unit 144, and supplies the inter prediction mode information and the motion vector information to the information decoding unit 242.

Furthermore, the lossless decoding unit 241 supplies intra prediction mode information or inter prediction mode information as encoded information to the switch 146. The lossless decoding unit 241 supplies offset filter information as encoded information to the adaptive offset filter 137 and supplies filter coefficients to the adaptive loop filter 138.

Since the processing in steps S232 through S234 is the same as the processing in steps S132 through S134 in FIG.

In step S235, the information decoding unit 242 generates a motion vector of the PU to be processed based on the motion vector encoding mode represented by the inter prediction information supplied from the lossless decoding unit 241.

In step S236, the motion compensation unit 245 performs motion compensation on a PU basis based on the motion vector supplied from the information decoding unit 242 and the inter prediction mode information and reference image specifying information supplied from the lossless decoding unit 241. Process. Details of this motion compensation processing will be described with reference to FIG. 33 described later.

Since the processing of steps S237 to S241 is the same as the processing of steps S137 to S141 in FIG. 32, description thereof is omitted.

In step S242, the enlargement / reduction unit 243 enlarges or reduces the image supplied from the adaptive loop filter 138 based on the enlargement / reduction rate correspondence information included in the PPS supplied from the extraction unit 112 in FIG. 244.

In step S243, the frame memory 244 stores the image supplied from the adder 135 and the image supplied from the enlargement / reduction unit 243. Pixels adjacent to the PU in the image that has not been subjected to filter processing accumulated in the frame memory 244 are supplied to the intra prediction unit 143 via the switch 142 as peripheral pixels. On the other hand, the filtered image stored in the frame memory 244 is supplied as a reference image to the motion compensation unit 144 via the switch 142.

Since steps S244 and S245 are the same as the processes of steps S143 and S144 in FIG.

FIG. 33 is a flowchart for explaining the details of the motion compensation processing in step S236 of FIG.

33 are the same as the processes of steps S150 to S152 and S156 to S158 of FIG. 23, and thus the description thereof is omitted.

As described above, the decoding unit 240 enlarges or reduces a decoded image that is a reference image candidate based on the enlargement / reduction ratio correspondence information, and generates a predicted image using the enlarged or reduced decoded image as a reference image. . Therefore, it is possible to decode the encoded stream that is encoded by the encoding device 10 including the encoding unit 200 so as to improve the encoding efficiency when the encoding target image is enlarged or reduced.

In the second embodiment, as in the case of the first embodiment, low-pass filter processing may be performed on an enlarged or reduced image.

<Third Embodiment>
(Description of computer to which the present disclosure is applied)
The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer capable of executing various functions by installing various programs by installing a computer incorporated in dedicated hardware.

FIG. 34 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processing by a program.

In the computer 500, a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, and a RAM (Random Access Memory) 503 are connected to each other via a bus 504.

An input / output interface 505 is further connected to the bus 504. An input unit 506, an output unit 507, a storage unit 508, a communication unit 509, and a drive 510 are connected to the input / output interface 505.

The input unit 506 includes a keyboard, a mouse, a microphone, and the like. The output unit 507 includes a display, a speaker, and the like. The storage unit 508 includes a hard disk, a nonvolatile memory, and the like. The communication unit 509 includes a network interface or the like. The drive 510 drives a removable medium 511 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

In the computer 500 configured as described above, for example, the CPU 501 loads the program stored in the storage unit 508 to the RAM 503 via the input / output interface 505 and the bus 504 and executes the program. A series of processing is performed.

The program executed by the computer 500 (CPU 501) can be provided by being recorded on a removable medium 511 as a package medium, for example. The program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

In the computer 500, the program can be installed in the storage unit 508 via the input / output interface 505 by installing the removable medium 511 in the drive 510. Further, the program can be received by the communication unit 509 via a wired or wireless transmission medium and installed in the storage unit 508. In addition, the program can be installed in the ROM 502 or the storage unit 508 in advance.

Note that the program executed by the computer 500 may be a program that is processed in time series in the order described in this specification, or a necessary timing such as in parallel or when a call is made. It may be a program in which processing is performed.

<Fourth embodiment>
(Application to multi-view image coding and multi-view image decoding)
The series of processes described above can be applied to multi-view image encoding / multi-view image decoding. FIG. 35 shows an example of a multi-view image encoding method.

As shown in FIG. 35, the multi-viewpoint image includes images of a plurality of viewpoints (views). Multiple views of this multi-viewpoint image are encoded using the base view that encodes and decodes using only the image of its own view without using the image of the other view, and the image of the other view. -It consists of a non-base view that performs decoding. For the non-base view, an image of the base view may be used, or an image of another non-base view may be used.

In the case of encoding / decoding a multi-view image as shown in FIG. 35, each view image is encoded / decoded. For the encoding / decoding of each view, the first and second embodiments described above are used. You may make it apply a method. By doing so, it is possible to improve the encoding efficiency when the image to be encoded is enlarged or reduced.

Furthermore, in encoding / decoding of each view, flags and parameters used in the methods of the first and second embodiments described above may be shared. More specifically, for example, mvd_coding, PPS syntax elements, and the like may be shared in encoding / decoding of each view. Of course, other necessary information may be shared in encoding / decoding of each view.

By doing in this way, transmission of redundant information can be suppressed and the amount of information to be transmitted (code amount) can be reduced (that is, reduction in encoding efficiency can be suppressed).

(Multi-view image encoding device)
FIG. 36 is a diagram illustrating a multi-view image encoding apparatus that performs the above-described multi-view image encoding. As illustrated in FIG. 36, the multi-view image encoding apparatus 600 includes an encoding unit 601, an encoding unit 602, and a multiplexing unit 603.

The cocoon encoding unit 601 encodes the base view image and generates a base view image encoded stream. The encoding unit 602 encodes the non-base view image and generates a non-base view image encoded stream. The multiplexing unit 603 multiplexes the base view image encoded stream generated by the encoding unit 601 and the non-base view image encoded stream generated by the encoding unit 602 to generate a multi-view image encoded stream. To do.

The first and second embodiments of the encoding device can be applied to the encoding unit 601 and the encoding unit 602 of the multi-view image encoding device 600. That is, in the encoding for each view, it is possible to improve the encoding efficiency when the image to be encoded is enlarged or reduced. Also, the encoding unit 601 and the encoding unit 602 can perform encoding using the same flags and parameters (for example, syntax elements related to processing between images) (that is, share the flags and parameters). Therefore, it is possible to suppress a reduction in encoding efficiency.

(Multi-viewpoint image decoding device)
FIG. 37 is a diagram illustrating a multi-view image decoding apparatus that performs the above-described multi-view image decoding. As illustrated in FIG. 37, the multi-view image decoding device 610 includes a demultiplexing unit 611, a decoding unit 612, and a decoding unit 613.

The demultiplexing unit 611 demultiplexes the multi-view image encoded stream in which the base view image encoded stream and the non-base view image encoded stream are multiplexed, and the base view image encoded stream and the non-base view image The encoded stream is extracted. The decoding unit 612 decodes the base view image encoded stream extracted by the demultiplexing unit 611 to obtain a base view image. The decoding unit 613 decodes the non-base view image encoded stream extracted by the demultiplexing unit 611 to obtain a non-base view image.

The first and second embodiments of the decoding device can be applied to the decoding unit 612 and the decoding unit 613 of the multi-view image decoding device 610. That is, in decoding for each view, it is possible to decode an encoded stream that has been encoded so as to improve encoding efficiency when an image to be encoded is enlarged or reduced. In addition, the decoding unit 612 and the decoding unit 613 can perform decoding using the same flags and parameters (for example, syntax elements related to processing between images) (that is, the flags and parameters can be shared). Therefore, it is possible to suppress a reduction in encoding efficiency.

<Fifth embodiment>
(Application to hierarchical image coding / hierarchical image decoding)
The series of processes described above can be applied to hierarchical image encoding / hierarchical image decoding (scalable encoding / scalable decoding). FIG. 38 shows an example of a hierarchical image encoding method.

Hierarchical image coding (scalable coding) is a method in which image data is divided into a plurality of layers (hierarchized) so as to have a scalable function with respect to a predetermined parameter, and is encoded for each layer. Hierarchical image decoding (scalable decoding) is decoding corresponding to the hierarchical image encoding.

38. As shown in FIG. 38, in image hierarchization, one image is divided into a plurality of images (layers) based on a predetermined parameter having a scalable function. That is, the hierarchized image (hierarchical image) includes images of a plurality of hierarchies (layers) having different predetermined parameter values. A plurality of layers of this hierarchical image are encoded / decoded using only the image of the own layer without using the image of the other layer, and encoded / decoded using the image of the other layer. It consists of a non-base layer (also called enhancement layer) that performs decoding. As the non-base layer, an image of the base layer may be used, or an image of another non-base layer may be used.

Generally, the non-base layer is composed of difference image data (difference data) between its own image and an image of another layer so that redundancy is reduced. For example, when one image is divided into two layers of a base layer and a non-base layer (also referred to as an enhancement layer), an image with lower quality than the original image can be obtained using only the base layer data. By synthesizing the base layer data, an original image (that is, a high-quality image) can be obtained.

By layering images in this way, images of various qualities can be easily obtained according to the situation. For example, to a terminal with low processing capability such as a mobile phone, image compression information of only the base layer (base layer) is transmitted, and a moving image with low spatiotemporal resolution or poor image quality is reproduced. For terminals with high processing power, such as televisions and personal computers, in addition to the base layer (base layer), image enhancement information of the enhancement layer (enhancement layer) is transmitted. Image compression information corresponding to the capabilities of the terminal and the network can be transmitted from the server without performing transcoding processing, such as playing a moving image with high image quality.

In the case of encoding / decoding the hierarchical image as in the example of FIG. 38, the image of each layer is encoded / decoded. For the encoding / decoding of each layer, the first and second embodiments described above are used. The method may be applied. By doing so, it is possible to improve the encoding efficiency when the image to be encoded is enlarged or reduced.

Furthermore, in encoding / decoding of each layer, the flags and parameters used in the methods of the first and second embodiments described above may be shared. More specifically, for example, mvd_coding, PPS syntax elements, and the like may be shared in encoding / decoding of each layer. Of course, other necessary information may be shared in encoding / decoding of each layer.

(Scalable parameters)
In such hierarchical image encoding / hierarchical image decoding (scalable encoding / scalable decoding), parameters having a scalable function are arbitrary. For example, the spatial resolution as shown in FIG. 39 may be used as the parameter (spatial scalability). In the case of this spatial scalability, the resolution of the image is different for each layer. That is, in this case, as shown in FIG. 39, each picture has two layers of a base layer having a spatially lower resolution than the original image and an enhancement layer in which the original spatial resolution is obtained by combining with the base layer. Is layered. Of course, this number of hierarchies is an example, and the number of hierarchies can be hierarchized.

In addition, as a parameter for providing such a scalable property, for example, a temporal resolution as shown in FIG. 40 may be applied (temporal scalability). In the case of this temporal scalability (temporal scalability), the frame rate is different for each layer. That is, in this case, as shown in FIG. 40, each picture is divided into two layers of a base layer having a lower frame rate than the original moving image and an enhancement layer in which the original frame rate is obtained by combining with the base layer. Layered. Of course, this number of hierarchies is an example, and the number of hierarchies can be hierarchized.

Furthermore, for example, a signal-to-noise ratio (SNR (Signal to Noise ratio)) may be applied (SNR せる scalability) as a parameter for providing such scalability. In the case of this SNR scalability (SNR scalability), the SN ratio is different for each layer. That is, in this case, as shown in FIG. 41, each picture is hierarchized into two layers: a base layer having a lower SNR than the original image, and an enhancement layer from which the original SNR is obtained by combining with the base layer. The Of course, this number of hierarchies is an example, and the number of hierarchies can be hierarchized.

Of course, parameters other than the above-described example may be used as the parameters for providing scalability. For example, bit depth can also be used as a parameter for providing scalability (bit-depth scalability). In the case of this bit depth scalability (bit-depth scalability), the bit depth differs for each layer. In this case, for example, the base layer is composed of an 8-bit image, and an enhancement layer is added to the base layer, whereby a 10-bit image can be obtained.

In addition, a chroma format can be used as a parameter for providing scalability (chroma scalability). In the case of this chroma scalability, the chroma format differs for each layer. In this case, for example, the base layer (base layer) is composed of component images in 4: 2: 0 format, and by adding an enhancement layer (enhancement layer) to this, a component image in 4: 2: 2 format can be obtained. Can be.

(Hierarchical image encoding device)
FIG. 42 is a diagram illustrating a hierarchical image encoding apparatus that performs the hierarchical image encoding described above. As illustrated in FIG. 42, the hierarchical image encoding device 620 includes an encoding unit 621, an encoding unit 622, and a multiplexing unit 623.

The cocoon encoding unit 621 encodes the base layer image and generates a base layer image encoded stream. The encoding unit 622 encodes the non-base layer image and generates a non-base layer image encoded stream. The multiplexing unit 623 multiplexes the base layer image encoded stream generated by the encoding unit 621 and the non-base layer image encoded stream generated by the encoding unit 622 to generate a hierarchical image encoded stream. .

The first and second embodiments of the encoding device can be applied to the encoding unit 621 and the encoding unit 622 of the hierarchical image encoding device 620. That is, in the encoding for each layer, it is possible to improve the encoding efficiency when the image to be encoded is enlarged or reduced. Also, the encoding unit 621 and the encoding unit 622 can perform control of intra prediction filter processing using the same flags and parameters (for example, syntax elements related to processing between images) (that is, the intra prediction processing). Therefore, it is possible to share a flag and a parameter), and it is possible to suppress a reduction in encoding efficiency.

(Hierarchical image decoding device)
FIG. 43 is a diagram illustrating a hierarchical image decoding apparatus that performs the above-described hierarchical image decoding. As illustrated in FIG. 43, the hierarchical image decoding device 630 includes a demultiplexing unit 631, a decoding unit 632, and a decoding unit 633.

The demultiplexing unit 631 demultiplexes the hierarchical image encoded stream in which the base layer image encoded stream and the non-base layer image encoded stream are multiplexed, and the base layer image encoded stream and the non-base layer image code Stream. The decoding unit 632 decodes the base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a base layer image. The decoding unit 633 decodes the non-base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a non-base layer image.

The first and second embodiments of the decoding device can be applied to the decoding unit 632 and the decoding unit 633 of the hierarchical image decoding device 630. That is, in the decoding for each layer, it is possible to decode an encoded stream that has been encoded so as to improve the encoding efficiency when the image to be encoded is enlarged or reduced. In addition, the decoding unit 612 and the decoding unit 613 can perform decoding using the same flags and parameters (for example, syntax elements related to processing between images) (that is, the flags and parameters can be shared). Therefore, it is possible to suppress a reduction in encoding efficiency.

<Sixth embodiment>
(Example configuration of television device)
FIG. 44 illustrates a schematic configuration of a television apparatus to which the present technology is applied. The television apparatus 900 includes an antenna 901, a tuner 902, a demultiplexer 903, a decoder 904, a video signal processing unit 905, a display unit 906, an audio signal processing unit 907, a speaker 908, and an external interface unit 909. Furthermore, the television apparatus 900 includes a control unit 910, a user interface unit 911, and the like.

The tuner 902 selects a desired channel from the broadcast wave signal received by the antenna 901, demodulates it, and outputs the obtained encoded bit stream to the demultiplexer 903.

The demultiplexer 903 extracts video and audio packets of the program to be viewed from the encoded bit stream, and outputs the extracted packet data to the decoder 904. Further, the demultiplexer 903 supplies a packet of data such as EPG (Electronic Program Guide) to the control unit 910. If scrambling is being performed, descrambling is performed by a demultiplexer or the like.

The decoder 904 performs packet decoding processing, and outputs video data generated by the decoding processing to the video signal processing unit 905 and audio data to the audio signal processing unit 907.

The video signal processing unit 905 performs noise removal, video processing according to user settings, and the like on the video data. The video signal processing unit 905 generates video data of a program to be displayed on the display unit 906, image data by processing based on an application supplied via a network, and the like. The video signal processing unit 905 generates video data for displaying a menu screen for selecting an item and the like, and superimposes the video data on the video data of the program. The video signal processing unit 905 generates a drive signal based on the video data generated in this way, and drives the display unit 906.

The display unit 906 drives a display device (for example, a liquid crystal display element or the like) based on a drive signal from the video signal processing unit 905 to display a program video or the like.

The audio signal processing unit 907 performs predetermined processing such as noise removal on the audio data, performs D / A conversion processing and amplification processing on the processed audio data, and outputs the audio data to the speaker 908.

The external interface unit 909 is an interface for connecting to an external device or a network, and transmits and receives data such as video data and audio data.

A user interface unit 911 is connected to the control unit 910. The user interface unit 911 includes an operation switch, a remote control signal receiving unit, and the like, and supplies an operation signal corresponding to a user operation to the control unit 910.

The control unit 910 is configured using a CPU (Central Processing Unit), a memory, and the like. The memory stores a program executed by the CPU, various data necessary for the CPU to perform processing, EPG data, data acquired via a network, and the like. The program stored in the memory is read and executed by the CPU at a predetermined timing such as when the television device 900 is activated. The CPU executes each program to control each unit so that the television device 900 operates in accordance with the user operation.

Note that the television device 900 includes a bus 912 for connecting the tuner 902, the demultiplexer 903, the video signal processing unit 905, the audio signal processing unit 907, the external interface unit 909, and the control unit 910.

In the thus configured television apparatus, the decoder 904 is provided with the function of the decoding apparatus (decoding method) of the present application. Therefore, it is possible to decode an encoded stream that has been encoded so as to improve the encoding efficiency when an image to be encoded is enlarged or reduced.

<Seventh embodiment>
(Configuration example of mobile phone)
FIG. 45 illustrates a schematic configuration of a mobile phone to which the present technology is applied. The cellular phone 920 includes a communication unit 922, an audio codec 923, a camera unit 926, an image processing unit 927, a demultiplexing unit 928, a recording / reproducing unit 929, a display unit 930, and a control unit 931. These are connected to each other via a bus 933.

In addition, an antenna 921 is connected to the communication unit 922, and a speaker 924 and a microphone 925 are connected to the audio codec 923. Further, an operation unit 932 is connected to the control unit 931.

The mobile phone 920 performs various operations such as transmission / reception of voice signals, transmission / reception of e-mail and image data, image shooting, and data recording in various modes such as a voice call mode and a data communication mode.

In the voice call mode, the voice signal generated by the microphone 925 is converted into voice data and compressed by the voice codec 923 and supplied to the communication unit 922. The communication unit 922 performs audio data modulation processing, frequency conversion processing, and the like to generate a transmission signal. The communication unit 922 supplies a transmission signal to the antenna 921 and transmits it to a base station (not shown). In addition, the communication unit 922 performs amplification, frequency conversion processing, demodulation processing, and the like of the reception signal received by the antenna 921, and supplies the obtained audio data to the audio codec 923. The audio codec 923 performs data expansion of the audio data and conversion into an analog audio signal and outputs the result to the speaker 924.

In the data communication mode, when mail transmission is performed, the control unit 931 receives character data input by operating the operation unit 932 and displays the input characters on the display unit 930. In addition, the control unit 931 generates mail data based on a user instruction or the like in the operation unit 932 and supplies the mail data to the communication unit 922. The communication unit 922 performs mail data modulation processing, frequency conversion processing, and the like, and transmits the obtained transmission signal from the antenna 921. In addition, the communication unit 922 performs amplification, frequency conversion processing, demodulation processing, and the like of the reception signal received by the antenna 921, and restores mail data. This mail data is supplied to the display unit 930 to display the mail contents.

Note that the mobile phone 920 can also store the received mail data in a storage medium by the recording / playback unit 929. The storage medium is any rewritable storage medium. For example, the storage medium is a removable memory such as a RAM, a semiconductor memory such as a built-in flash memory, a hard disk, a magnetic disk, a magneto-optical disk, an optical disk, a USB (Universal Serial Bus) memory, or a memory card.

When transmitting image data in the data communication mode, the image data generated by the camera unit 926 is supplied to the image processing unit 927. The image processing unit 927 performs encoding processing of image data and generates encoded data.

The demultiplexing unit 928 multiplexes the encoded data generated by the image processing unit 927 and the audio data supplied from the audio codec 923 by a predetermined method, and supplies the multiplexed data to the communication unit 922. The communication unit 922 performs modulation processing and frequency conversion processing of multiplexed data, and transmits the obtained transmission signal from the antenna 921. In addition, the communication unit 922 performs amplification, frequency conversion processing, demodulation processing, and the like of the reception signal received by the antenna 921, and restores multiplexed data. This multiplexed data is supplied to the demultiplexing unit 928. The demultiplexing unit 928 performs demultiplexing of the multiplexed data, and supplies the encoded data to the image processing unit 927 and the audio data to the audio codec 923. The image processing unit 927 performs a decoding process on the encoded data to generate image data. The image data is supplied to the display unit 930 and the received image is displayed. The audio codec 923 converts the audio data into an analog audio signal, supplies the analog audio signal to the speaker 924, and outputs the received audio.

In the cellular phone device configured as described above, the image processing unit 927 is provided with the functions of the encoding device and the decoding device (encoding method and decoding method) of the present application. For this reason, it is possible to improve the encoding efficiency when the image to be encoded is enlarged or reduced. Also, it is possible to decode an encoded stream that has been encoded so as to improve encoding efficiency when an image to be encoded is enlarged or reduced.

<Eighth embodiment>
(Configuration example of recording / reproducing apparatus)
FIG. 46 illustrates a schematic configuration of a recording / reproducing apparatus to which the present technology is applied. The recording / reproducing apparatus 940 records, for example, audio data and video data of a received broadcast program on a recording medium, and provides the recorded data to the user at a timing according to a user instruction. The recording / reproducing device 940 can also acquire audio data and video data from another device, for example, and record them on a recording medium. Further, the recording / reproducing apparatus 940 decodes and outputs the audio data and video data recorded on the recording medium, thereby enabling image display and audio output on the monitor apparatus or the like.

The recording / reproducing apparatus 940 includes a tuner 941, an external interface unit 942, an encoder 943, an HDD (Hard Disk Drive) unit 944, a disk drive 945, a selector 946, a decoder 947, an OSD (On-Screen Display) unit 948, a control unit 949, A user interface unit 950 is included.

Tuner 941 selects a desired channel from a broadcast signal received by an antenna (not shown). The tuner 941 outputs an encoded bit stream obtained by demodulating the received signal of a desired channel to the selector 946.

The external interface unit 942 includes at least one of an IEEE 1394 interface, a network interface unit, a USB interface, a flash memory interface, and the like. The external interface unit 942 is an interface for connecting to an external device, a network, a memory card, and the like, and receives data such as video data and audio data to be recorded.

The encoder 943 performs encoding by a predetermined method when the video data and audio data supplied from the external interface unit 942 are not encoded, and outputs an encoded bit stream to the selector 946.

The HDD unit 944 records content data such as video and audio, various programs, and other data on a built-in hard disk, and reads them from the hard disk during playback.

The disk drive 945 records and reproduces signals with respect to the mounted optical disk. An optical disk such as a DVD disk (DVD-Video, DVD-RAM, DVD-R, DVD-RW, DVD + R, DVD + RW, etc.), a Blu-ray (registered trademark) disk, or the like.

The selector 946 selects one of the encoded bit streams from the tuner 941 or the encoder 943 and supplies it to either the HDD unit 944 or the disk drive 945 when recording video or audio. Further, the selector 946 supplies the encoded bit stream output from the HDD unit 944 or the disk drive 945 to the decoder 947 at the time of reproduction of video and audio.

The decoder 947 performs a decoding process on the encoded bit stream. The decoder 947 supplies the video data generated by performing the decoding process to the OSD unit 948. The decoder 947 outputs audio data generated by performing the decoding process.

The OSD unit 948 generates video data for displaying a menu screen for selecting an item and the like, and superimposes it on the video data output from the decoder 947 and outputs the video data.

A user interface unit 950 is connected to the control unit 949. The user interface unit 950 includes an operation switch, a remote control signal receiving unit, and the like, and supplies an operation signal corresponding to a user operation to the control unit 949.

The control unit 949 is configured using a CPU, a memory, and the like. The memory stores programs executed by the CPU and various data necessary for the CPU to perform processing. The program stored in the memory is read and executed by the CPU at a predetermined timing such as when the recording / reproducing apparatus 940 is activated. The CPU executes the program to control each unit so that the recording / reproducing device 940 operates according to the user operation.

In the recording / reproducing apparatus configured as described above, the decoder 947 is provided with the function of the decoding apparatus (decoding method) of the present application. Therefore, it is possible to decode an encoded stream that has been encoded so as to improve the encoding efficiency when an image to be encoded is enlarged or reduced.

<Ninth Embodiment>
(Configuration example of imaging device)
FIG. 47 illustrates a schematic configuration of an imaging apparatus to which the present technology is applied. The imaging device 960 images a subject, displays an image of the subject on a display unit, and records it on a recording medium as image data.

The imaging device 960 includes an optical block 961, an imaging unit 962, a camera signal processing unit 963, an image data processing unit 964, a display unit 965, an external interface unit 966, a memory unit 967, a media drive 968, an OSD unit 969, and a control unit 970. Have. In addition, a user interface unit 971 is connected to the control unit 970. Furthermore, the image data processing unit 964, the external interface unit 966, the memory unit 967, the media drive 968, the OSD unit 969, the control unit 970, and the like are connected via a bus 972.

The optical block 961 is configured using a focus lens, a diaphragm mechanism, and the like. The optical block 961 forms an optical image of the subject on the imaging surface of the imaging unit 962. The imaging unit 962 is configured using a CCD or CMOS image sensor, generates an electrical signal corresponding to the optical image by photoelectric conversion, and supplies the electrical signal to the camera signal processing unit 963.

The camera signal processing unit 963 performs various camera signal processing such as knee correction, gamma correction, and color correction on the electrical signal supplied from the imaging unit 962. The camera signal processing unit 963 supplies the image data after the camera signal processing to the image data processing unit 964.

The image data processing unit 964 performs an encoding process on the image data supplied from the camera signal processing unit 963. The image data processing unit 964 supplies the encoded data generated by performing the encoding process to the external interface unit 966 and the media drive 968. Further, the image data processing unit 964 performs a decoding process on the encoded data supplied from the external interface unit 966 and the media drive 968. The image data processing unit 964 supplies the image data generated by performing the decoding process to the display unit 965. Further, the image data processing unit 964 superimposes the processing for supplying the image data supplied from the camera signal processing unit 963 to the display unit 965 and the display data acquired from the OSD unit 969 on the image data. To supply.

The OSD unit 969 generates display data such as a menu screen and icons made up of symbols, characters, or figures and outputs them to the image data processing unit 964.

The external interface unit 966 includes, for example, a USB input / output terminal, and is connected to a printer when printing an image. In addition, a drive is connected to the external interface unit 966 as necessary, a removable medium such as a magnetic disk or an optical disk is appropriately mounted, and a computer program read from them is installed as necessary. Furthermore, the external interface unit 966 has a network interface connected to a predetermined network such as a LAN or the Internet. For example, the control unit 970 reads encoded data from the media drive 968 in accordance with an instruction from the user interface unit 971, and supplies the encoded data to the other device connected via the network from the external interface unit 966. it can. Also, the control unit 970 may acquire encoded data and image data supplied from another device via the network via the external interface unit 966 and supply the acquired data to the image data processing unit 964. it can.

As the recording medium driven by the media drive 968, any readable / writable removable medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory is used. The recording medium may be any type of removable medium, and may be a tape device, a disk, or a memory card. Of course, a non-contact IC (Integrated Circuit) card may be used.

Further, the media drive 968 and the recording medium may be integrated and configured by a non-portable storage medium such as a built-in hard disk drive or an SSD (Solid State Drive).

The control unit 970 is configured using a CPU. The memory unit 967 stores a program executed by the control unit 970, various data necessary for the control unit 970 to perform processing, and the like. The program stored in the memory unit 967 is read and executed by the control unit 970 at a predetermined timing such as when the imaging device 960 is activated. The control unit 970 controls each unit so that the imaging device 960 performs an operation according to a user operation by executing a program.

In the imaging apparatus configured as described above, the image data processing unit 964 is provided with the functions of the encoding apparatus and decoding apparatus (encoding method and decoding method) of the present application. For this reason, it is possible to improve the encoding efficiency when the image to be encoded is enlarged or reduced. Also, it is possible to decode an encoded stream that has been encoded so as to improve encoding efficiency when an image to be encoded is enlarged or reduced.

<Application example of scalable coding>
(First system)
Next, a specific usage example of scalable encoded data that has been subjected to scalable encoding (hierarchical encoding) will be described. The scalable coding is used for selection of data to be transmitted, for example, as in the example shown in FIG.

In the data transmission system 1000 shown in FIG. 48, the distribution server 1002 reads the scalable encoded data stored in the scalable encoded data storage unit 1001, and via the network 1003, the personal computer 1004, the AV device 1005, the tablet This is distributed to the terminal device such as the device 1006 and the mobile phone 1007.

At this time, the distribution server 1002 selects and transmits encoded data of appropriate quality according to the capability of the terminal device, the communication environment, and the like. Even if the distribution server 1002 transmits unnecessarily high-quality data, the terminal device does not always obtain a high-quality image, and may cause a delay or an overflow. Moreover, there is a possibility that the communication band is unnecessarily occupied or the load on the terminal device is unnecessarily increased. On the other hand, even if the distribution server 1002 transmits unnecessarily low quality data, there is a possibility that an image with sufficient image quality cannot be obtained in the terminal device. Therefore, the distribution server 1002 appropriately reads and transmits the scalable encoded data stored in the scalable encoded data storage unit 1001 as encoded data having an appropriate quality with respect to the capability and communication environment of the terminal device. .

For example, it is assumed that the scalable encoded data storage unit 1001 stores scalable encoded data (BL + EL) 1011 encoded in a scalable manner. The scalable encoded data (BL + EL) 1011 is encoded data including both a base layer and an enhancement layer, and is a data that can be decoded to obtain both a base layer image and an enhancement layer image. It is.

The distribution server 1002 selects an appropriate layer according to the capability of the terminal device that transmits data, the communication environment, and the like, and reads the data of the layer. For example, the distribution server 1002 reads high-quality scalable encoded data (BL + EL) 1011 from the scalable encoded data storage unit 1001 and transmits it to the personal computer 1004 and the tablet device 1006 with high processing capability as they are. . On the other hand, for example, the distribution server 1002 extracts base layer data from the scalable encoded data (BL + EL) 1011 for the AV device 1005 and the cellular phone 1007 having a low processing capability, and performs scalable encoding. Although it is data of the same content as the data (BL + EL) 1011, it is transmitted as scalable encoded data (BL) 1012 having a lower quality than the scalable encoded data (BL + EL) 1011.

By using scalable encoded data in this way, the amount of data can be easily adjusted, so that the occurrence of delay and overflow can be suppressed, and the unnecessary increase in the load on the terminal device and communication medium can be suppressed. be able to. In addition, since scalable encoded data (BL + EL) 1011 has reduced redundancy between layers, the amount of data can be reduced as compared with the case where encoded data of each layer is used as individual data. . Therefore, the storage area of the scalable encoded data storage unit 1001 can be used more efficiently.

Note that since various devices can be applied to the terminal device, such as the personal computer 1004 to the cellular phone 1007, the hardware performance of the terminal device varies depending on the device. Moreover, since the application which a terminal device performs is also various, the capability of the software is also various. Furthermore, the network 1003 serving as a communication medium can be applied to any communication network including wired, wireless, or both, such as the Internet and a LAN (Local Area Network), and has various data transmission capabilities. Furthermore, there is a risk of change due to other communications.

Therefore, the distribution server 1002 communicates with the terminal device that is the data transmission destination before starting data transmission, and the hardware performance of the terminal device, the performance of the application (software) executed by the terminal device, etc. Information regarding the capability of the terminal device and information regarding the communication environment such as the available bandwidth of the network 1003 may be obtained. The distribution server 1002 may select an appropriate layer based on the information obtained here.

Note that the layer extraction may be performed by the terminal device. For example, the personal computer 1004 may decode the transmitted scalable encoded data (BL + EL) 1011 and display a base layer image or an enhancement layer image. Further, for example, the personal computer 1004 extracts the base layer scalable encoded data (BL) 1012 from the transmitted scalable encoded data (BL + EL) 1011 and stores it or transfers it to another device. The base layer image may be displayed after decoding.

Of course, the numbers of the scalable encoded data storage unit 1001, the distribution server 1002, the network 1003, and the terminal devices are arbitrary. In the above, the example in which the distribution server 1002 transmits data to the terminal device has been described, but the usage example is not limited to this. The data transmission system 1000 may be any system as long as it transmits a scalable encoded data to a terminal device by selecting an appropriate layer according to the capability of the terminal device or a communication environment. Can be applied to the system.

(Second system)
In addition, scalable coding is used for transmission via a plurality of communication media as in the example shown in FIG. 49, for example.

49, a broadcasting station 1101 transmits base layer scalable encoded data (BL) 1121 by terrestrial broadcasting 1111. In the data transmission system 1100 shown in FIG. Also, the broadcast station 1101 transmits enhancement layer scalable encoded data (EL) 1122 via an arbitrary network 1112 including a wired or wireless communication network or both (for example, packetized transmission).

The terminal apparatus 1102 has a reception function of the terrestrial broadcast 1111 broadcast by the broadcast station 1101 and receives base layer scalable encoded data (BL) 1121 transmitted via the terrestrial broadcast 1111. The terminal apparatus 1102 further has a communication function for performing communication via the network 1112, and receives enhancement layer scalable encoded data (EL) 1122 transmitted via the network 1112.

The terminal device 1102 decodes the base layer scalable encoded data (BL) 1121 acquired via the terrestrial broadcast 1111 according to, for example, a user instruction, and obtains or stores a base layer image. Or transmit to other devices.

Also, the terminal device 1102, for example, in response to a user instruction, the base layer scalable encoded data (BL) 1121 acquired via the terrestrial broadcast 1111 and the enhancement layer scalable encoded acquired via the network 1112 Data (EL) 1122 is combined to obtain scalable encoded data (BL + EL), or decoded to obtain an enhancement layer image, stored, or transmitted to another device.

As described above, the scalable encoded data can be transmitted via a communication medium that is different for each layer, for example. Therefore, the load can be distributed, and the occurrence of delay and overflow can be suppressed.

Also, depending on the situation, the communication medium used for transmission may be selected for each layer. For example, scalable encoded data (BL) 1121 of a base layer having a relatively large amount of data is transmitted via a communication medium having a wide bandwidth, and scalable encoded data (EL) 1122 having a relatively small amount of data is transmitted. You may make it transmit via a communication medium with a narrow bandwidth. Further, for example, the communication medium for transmitting the enhancement layer scalable encoded data (EL) 1122 is switched between the network 1112 and the terrestrial broadcast 1111 according to the available bandwidth of the network 1112. May be. Of course, the same applies to data of an arbitrary layer.

By controlling in this way, an increase in load in data transmission can be further suppressed.

Of course, the number of layers is arbitrary, and the number of communication media used for transmission is also arbitrary. In addition, the number of terminal devices 1102 serving as data distribution destinations is also arbitrary. Furthermore, in the above description, broadcasting from the broadcasting station 1101 has been described as an example, but the usage example is not limited to this. The data transmission system 1100 can be applied to any system as long as it is a system that divides scalable encoded data into a plurality of layers and transmits them through a plurality of lines.

(Third system)
Also, scalable coding is used for storing coded data, for example, as in the example shown in FIG.

In the imaging system 1200 shown in FIG. 50, the imaging device 1201 performs scalable coding on the image data obtained by imaging the subject 1211, and obtains scalable coded data (BL + EL) 1221 as a scalable coded data storage device 1202. To supply.

The scalable encoded data storage device 1202 stores the scalable encoded data (BL + EL) 1221 supplied from the imaging device 1201 with quality according to the situation. For example, in the normal case, the scalable encoded data storage device 1202 extracts base layer data from the scalable encoded data (BL + EL) 1221, and the base layer scalable encoded data ( BL) 1222. On the other hand, for example, in the case of attention, the scalable encoded data storage device 1202 stores scalable encoded data (BL + EL) 1221 with high quality and a large amount of data.

By doing so, the scalable encoded data storage device 1202 can store an image with high image quality only when necessary, so that an increase in the amount of data can be achieved while suppressing a reduction in the value of the image due to image quality degradation. And the use efficiency of the storage area can be improved.

For example, assume that the imaging device 1201 is a surveillance camera. When the monitoring target (for example, an intruder) is not shown in the captured image (in the normal case), the content of the captured image is likely to be unimportant, so reduction of the data amount is given priority, and the image data (scalable coding) Data) is stored in low quality. On the other hand, when the monitoring target appears in the captured image as the subject 1211 (at the time of attention), since the content of the captured image is likely to be important, the image quality is given priority and the image data (scalable) (Encoded data) is stored with high quality.

Note that whether it is normal time or attention time may be determined by the scalable encoded data storage device 1202 analyzing an image, for example. Alternatively, the imaging apparatus 1201 may make a determination, and the determination result may be transmitted to the scalable encoded data storage device 1202.

It should be noted that the criterion for determining whether the time is normal or noting is arbitrary, and the content of the image as the criterion is arbitrary. Of course, conditions other than the contents of the image can also be used as the criterion. For example, it may be switched according to the volume or waveform of the recorded sound, may be switched at every predetermined time, or may be switched by an external instruction such as a user instruction.

In the above, an example of switching between the normal state and the attention state has been described. However, the number of states is arbitrary, for example, normal, slightly attention, attention, very attention, etc. Alternatively, three or more states may be switched. However, the upper limit number of states to be switched depends on the number of layers of scalable encoded data.

Also, the imaging apparatus 1201 may determine the number of layers for scalable coding according to the state. For example, in a normal case, the imaging apparatus 1201 may generate base layer scalable encoded data (BL) 1222 with low quality and a small amount of data, and supply the scalable encoded data storage apparatus 1202 to the scalable encoded data storage apparatus 1202. For example, when attention is paid, the imaging device 1201 generates scalable encoded data (BL + EL) 1221 having a high quality and a large amount of data, and supplies the scalable encoded data storage device 1202 to the scalable encoded data storage device 1202. May be.

In the above, the monitoring camera has been described as an example. However, the use of the imaging system 1200 is arbitrary and is not limited to the monitoring camera.

<Tenth embodiment>
(Other examples of implementation)
In the above, examples of devices and systems to which the present technology is applied have been described. However, the present technology is not limited thereto, and any configuration mounted on such devices or devices constituting the system, for example, a system LSI (Large Scale) Integration) etc., a module using a plurality of processors, etc., a unit using a plurality of modules, etc., a set in which other functions are added to the unit, etc. (that is, a partial configuration of the apparatus) .

(Video set configuration example)
An example in which the present technology is implemented as a set will be described with reference to FIG. FIG. 51 illustrates an example of a schematic configuration of a video set to which the present technology is applied.

In recent years, multi-functionalization of electronic devices has progressed, and in the development and manufacture, when implementing a part of the configuration as sales or provision, etc., not only when implementing as a configuration having one function, but also related In many cases, a plurality of configurations having functions are combined and implemented as a set having a plurality of functions.

The video set 1300 shown in FIG. 51 has such a multi-functional configuration, and a device having a function related to image encoding and decoding (either one or both) can be used for the function. It is a combination of devices having other related functions.

As shown in FIG. 51, the video set 1300 includes a module group such as a video module 1311, an external memory 1312, a power management module 1313, and a front-end module 1314, and a related group such as a connectivity 1321, a camera 1322, and a sensor 1323. And a device having a function.

A cocoon module is a component that has several functions that are related to each other and that have a coherent function. The specific physical configuration is arbitrary. For example, a plurality of processors each having a function, electronic circuit elements such as resistors and capacitors, and other devices arranged on a wiring board or the like can be considered. . It is also possible to combine the module with another module, a processor, or the like to form a new module.

51, the video module 1311 is a combination of configurations having functions related to image processing, and includes an application processor, a video processor, a broadband modem 1333, and an RF module 1334.

The processor is a configuration in which a configuration having a predetermined function is integrated on a semiconductor chip by an SoC (System On Chip), and for example, there is also a system LSI (Large Scale Integration) or the like. The configuration having the predetermined function may be a logic circuit (hardware configuration), a CPU, a ROM, a RAM, and the like, and a program (software configuration) executed using them. , Or a combination of both. For example, a processor has a logic circuit and a CPU, ROM, RAM, etc., a part of the function is realized by a logic circuit (hardware configuration), and other functions are executed by the CPU (software configuration) It may be realized by.

51 is a processor that executes an application related to image processing. The application executed in the application processor 1331 not only performs arithmetic processing to realize a predetermined function, but also can control the internal and external configurations of the video module 1311 such as the video processor 1332 as necessary. .

The video processor 1332 is a processor having a function related to image encoding / decoding (one or both of them).

The broadband modem 1333 is a processor (or module) that performs processing related to wired or wireless (or both) broadband communication performed via a broadband line such as the Internet or a public telephone line network. For example, the broadband modem 1333 digitally modulates data to be transmitted (digital signal) to convert it into an analog signal, or demodulates the received analog signal to convert it into data (digital signal). For example, the broadband modem 1333 can digitally modulate and demodulate arbitrary information such as image data processed by the video processor 1332, a stream obtained by encoding the image data, an application program, setting data, and the like.

The RF module 1334 is a module that performs frequency conversion, modulation / demodulation, amplification, filter processing, and the like on an RF (Radio RF Frequency) signal transmitted and received via an antenna. For example, the RF module 1334 generates an RF signal by performing frequency conversion or the like on the baseband signal generated by the broadband modem 1333. Further, for example, the RF module 1334 generates a baseband signal by performing frequency conversion or the like on the RF signal received via the front end module 1314.

Note that, as indicated by a dotted line 1341 in FIG. 51, the application processor 1331 and the video processor 1332 may be integrated into a single processor.

The external memory 1312 is a module having a storage device that is provided outside the video module 1311 and is used by the video module 1311. The storage device of the external memory 1312 may be realized by any physical configuration, but is generally used for storing a large amount of data such as image data in units of frames. For example, it is desirable to realize it with a relatively inexpensive and large-capacity semiconductor memory such as DRAM (Dynamic Random Access Memory).

The power management module 1313 manages and controls power supply to the video module 1311 (each component in the video module 1311).

The front end module 1314 is a module that provides the RF module 1334 with a front end function (a circuit on a transmitting / receiving end on the antenna side). As illustrated in FIG. 51, the front end module 1314 includes, for example, an antenna unit 1351, a filter 1352, and an amplifying unit 1353.

Antenna unit 1351 has an antenna for transmitting and receiving a radio signal and its peripheral configuration. The antenna unit 1351 transmits the signal supplied from the amplification unit 1353 as a radio signal, and supplies the received radio signal to the filter 1352 as an electric signal (RF signal). The filter 1352 performs a filtering process on the RF signal received via the antenna unit 1351 and supplies the processed RF signal to the RF module 1334. The amplifying unit 1353 amplifies the RF signal supplied from the RF module 1334 and supplies the amplified RF signal to the antenna unit 1351.

Connectivity 1321 is a module having a function related to connection with the outside. The physical configuration of the connectivity 1321 is arbitrary. For example, the connectivity 1321 has a configuration having a communication function other than the communication standard supported by the broadband modem 1333, an external input / output terminal, and the like.

For example, the communication 1321 is compliant with wireless communication standards such as Bluetooth (registered trademark), IEEE 802.11 (for example, Wi-Fi (Wireless Fidelity, registered trademark)), NFC (Near Field Communication), IrDA (InfraRed Data Association), etc. You may make it have a module which has a function, an antenna etc. which transmit / receive the signal based on the standard. Further, for example, the connectivity 1321 has a module having a communication function compliant with a wired communication standard such as USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), or a terminal compliant with the standard. You may do it. Further, for example, the connectivity 1321 may have other data (signal) transmission functions such as analog input / output terminals.

It should be noted that the connectivity 1321 may include a data (signal) transmission destination device. For example, the drive 1321 reads and writes data to and from a recording medium such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory (not only a removable medium drive, but also a hard disk, SSD (Solid State Drive) NAS (including Network Attached Storage) and the like. In addition, the connectivity 1321 may include an image or audio output device (a monitor, a speaker, or the like).

The eyelid camera 1322 is a module having a function of capturing an image of a subject and obtaining image data of the subject. Image data obtained by imaging by the camera 1322 is supplied to, for example, a video processor 1332 and encoded.

The sensor 1323 includes, for example, a voice sensor, an ultrasonic sensor, an optical sensor, an illuminance sensor, an infrared sensor, an image sensor, a rotation sensor, an angle sensor, an angular velocity sensor, a velocity sensor, an acceleration sensor, an inclination sensor, a magnetic identification sensor, an impact sensor, It is a module having an arbitrary sensor function such as a temperature sensor. For example, the data detected by the sensor 1323 is supplied to the application processor 1331 and used by an application or the like.

The configuration described above as a module may be realized as a processor, or conversely, the configuration described as a processor may be realized as a module.

In the video set 1300 configured as described above, the present technology can be applied to the video processor 1332 as described later. Therefore, the video set 1300 can be implemented as a set to which the present technology is applied.

(Video processor configuration example)
FIG. 52 shows an example of a schematic configuration of a video processor 1332 (FIG. 51) to which the present technology is applied.

In the case of the example of FIG. 52, the video processor 1332 receives the video signal and the audio signal and encodes them in a predetermined method, decodes the encoded video data and audio data, A function of reproducing and outputting an audio signal.

As shown in FIG. 52, the video processor 1332 includes a video input processing unit 1401, a first image enlargement / reduction unit 1402, a second image enlargement / reduction unit 1403, a video output processing unit 1404, a frame memory 1405, and a memory control unit 1406. Have The video processor 1332 includes an encoding / decoding engine 1407, video ES (ElementaryElementStream) buffers 1408A and 1408B, and audio ES buffers 1409A and 1409B. Further, the video processor 1332 includes an audio encoder 1410, an audio decoder 1411, a multiplexing unit (MUX (Multiplexer)) 1412, a demultiplexing unit (DMUX (Demultiplexer)) 1413, and a stream buffer 1414.

The video input processing unit 1401 acquires a video signal input from, for example, the connectivity 1321 (FIG. 51) and converts it into digital image data. The first image enlargement / reduction unit 1402 performs format conversion, image enlargement / reduction processing, and the like on the image data. The second image enlargement / reduction unit 1403 performs image enlargement / reduction processing on the image data in accordance with the format of the output destination via the video output processing unit 1404, or is the same as the first image enlargement / reduction unit 1402. Format conversion and image enlargement / reduction processing. The video output processing unit 1404 performs format conversion, conversion to an analog signal, and the like on the image data, and outputs the reproduced video signal to, for example, the connectivity 1321 (FIG. 51).

The frame memory 1405 is a memory for image data shared by the video input processing unit 1401, the first image scaling unit 1402, the second image scaling unit 1403, the video output processing unit 1404, and the encoding / decoding engine 1407. . The frame memory 1405 is realized as a semiconductor memory such as a DRAM, for example.

The memory control unit 1406 receives the synchronization signal from the encoding / decoding engine 1407, and controls the writing / reading access to the frame memory 1405 according to the access schedule to the frame memory 1405 written in the access management table 1406A. The access management table 1406A is updated by the memory control unit 1406 in accordance with processing executed by the encoding / decoding engine 1407, the first image enlargement / reduction unit 1402, the second image enlargement / reduction unit 1403, and the like.

The encoding / decoding engine 1407 performs encoding processing of image data and decoding processing of a video stream that is data obtained by encoding the image data. For example, the encoding / decoding engine 1407 encodes the image data read from the frame memory 1405 and sequentially writes the data as a video stream in the video ES buffer 1408A. Further, for example, the video stream is sequentially read from the video ES buffer 1408B, decoded, and sequentially written in the frame memory 1405 as image data. The encoding / decoding engine 1407 uses the frame memory 1405 as a work area in the encoding and decoding. Also, the encoding / decoding engine 1407 outputs a synchronization signal to the memory control unit 1406, for example, at a timing at which processing for each macroblock is started.

The video ES buffer 1408A buffers the video stream generated by the encoding / decoding engine 1407 and supplies the buffered video stream to the multiplexing unit (MUX) 1412. The video ES buffer 1408B buffers the video stream supplied from the demultiplexer (DMUX) 1413 and supplies the buffered video stream to the encoding / decoding engine 1407.

The audio ES buffer 1409A buffers the audio stream generated by the audio encoder 1410 and supplies the buffered audio stream to the multiplexing unit (MUX) 1412. The audio ES buffer 1409B buffers the audio stream supplied from the demultiplexer (DMUX) 1413 and supplies the buffered audio stream to the audio decoder 1411.

The audio encoder 1410 converts, for example, an audio signal input from the connectivity 1321 (FIG. 51), for example, into a digital format, and encodes the audio signal using a predetermined method such as an MPEG audio method or an AC3 (Audio Code number 3) method. The audio encoder 1410 sequentially writes an audio stream, which is data obtained by encoding an audio signal, in the audio ES buffer 1409A. The audio decoder 1411 decodes the audio stream supplied from the audio ES buffer 1409B, performs conversion to, for example, an analog signal, and supplies the reproduced audio signal to, for example, the connectivity 1321 (FIG. 51).

Multiplexer (MUX) 1412 multiplexes the video stream and the audio stream. The multiplexing method (that is, the format of the bit stream generated by multiplexing) is arbitrary. At the time of this multiplexing, the multiplexing unit (MUX) 1412 can also add predetermined header information or the like to the bit stream. That is, the multiplexing unit (MUX) 1412 can convert the stream format by multiplexing. For example, the multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream to convert it into a transport stream that is a bit stream in a transfer format. Further, for example, the multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream, thereby converting the data into file format data (file data) for recording.

The demultiplexing unit (DMUX) 1413 demultiplexes the bit stream in which the video stream and the audio stream are multiplexed by a method corresponding to the multiplexing by the multiplexing unit (MUX) 1412. That is, the demultiplexer (DMUX) 1413 extracts the video stream and the audio stream from the bit stream read from the stream buffer 1414 (separates the video stream and the audio stream). That is, the demultiplexer (DMUX) 1413 can convert the stream format by demultiplexing (inverse conversion of the conversion by the multiplexer (MUX) 1412). For example, the demultiplexing unit (DMUX) 1413 obtains a transport stream supplied from, for example, the connectivity 1321 and the broadband modem 1333 (both in FIG. 51) via the stream buffer 1414 and demultiplexes the transport stream. Can be converted into a video stream and an audio stream. Further, for example, the demultiplexer (DMUX) 1413 obtains the file data read from various recording media by the connectivity 1321 (FIG. 51) via the stream buffer 1414 and demultiplexes it, for example. It can be converted into a video stream and an audio stream.

The stream buffer 1414 buffers the bit stream. For example, the stream buffer 1414 buffers the transport stream supplied from the multiplexing unit (MUX) 1412 and, for example, at the predetermined timing or based on a request from the outside, for example, the connectivity 1321 or the broadband modem 1333 (whichever Are also supplied to FIG.

Further, for example, the stream buffer 1414 buffers the file data supplied from the multiplexing unit (MUX) 1412 and, for example, connectivity 1321 (FIG. 51) or the like at a predetermined timing or based on an external request or the like. To be recorded on various recording media.

Further, the stream buffer 1414 buffers the transport stream acquired through, for example, the connectivity 1321 and the broadband modem 1333 (both of which are shown in FIG. 51), and performs reverse processing at a predetermined timing or based on an external request or the like. The data is supplied to a multiplexing unit (DMUX) 1413.

In addition, the stream buffer 1414 buffers file data read from various recording media in the connectivity 1321 (FIG. 51), for example, and at a predetermined timing or based on an external request or the like, a demultiplexing unit (DMUX) 1413.

Next, an example of the operation of the video processor 1332 having such a configuration will be described. For example, a video signal input to the video processor 1332 from the connectivity 1321 (FIG. 51) or the like is converted into digital image data of a predetermined format such as 4: 2: 2Y / Cb / Cr format by the video input processing unit 1401. The data is sequentially written into the frame memory 1405. This digital image data is read by the first image enlargement / reduction unit 1402 or the second image enlargement / reduction unit 1403, and format conversion to a predetermined method such as 4: 2: 0Y / Cb / Cr method and enlargement / reduction processing are performed. Is written again in the frame memory 1405. This image data is encoded by the encoding / decoding engine 1407 and written as a video stream in the video ES buffer 1408A.

In addition, an audio signal input to the video processor 1332 from the connectivity 1321 (FIG. 51) or the like is encoded by the audio encoder 1410 and written as an audio stream in the audio ES buffer 1409A.

The video stream of the video ES buffer 1408A and the audio stream of the audio ES buffer 1409A are read and multiplexed by the multiplexing unit (MUX) 1412 and converted into a transport stream or file data. The transport stream generated by the multiplexing unit (MUX) 1412 is buffered in the stream buffer 1414 and then output to the external network via, for example, the connectivity 1321 and the broadband modem 1333 (both of which are shown in FIG. 51). Further, the file data generated by the multiplexing unit (MUX) 1412 is buffered in the stream buffer 1414, and then output to, for example, the connectivity 1321 (FIG. 51) and recorded on various recording media.

For example, a transport stream input from an external network to the video processor 1332 via the connectivity 1321 or the broadband modem 1333 (both in FIG. 51) is buffered in the stream buffer 1414 and then demultiplexed (DMUX). 1413 is demultiplexed. Further, for example, file data read from various recording media in the connectivity 1321 (FIG. 51) and inputted to the video processor 1332 is buffered in the stream buffer 1414 and then demultiplexed by the demultiplexer (DMUX) 1413. It becomes. That is, the transport stream or file data input to the video processor 1332 is separated into a video stream and an audio stream by the demultiplexer (DMUX) 1413.

The audio stream is supplied to the audio decoder 1411 via the audio ES buffer 1409B and decoded to reproduce the audio signal. The video stream is written to the video ES buffer 1408B, and then sequentially read and decoded by the encoding / decoding engine 1407, and written to the frame memory 1405. The decoded image data is enlarged / reduced by the second image enlargement / reduction unit 1403 and written to the frame memory 1405. The decoded image data is read out to the video output processing unit 1404, format-converted to a predetermined system such as 4: 2: 2Y / Cb / Cr system, and further converted into an analog signal to be converted into a video signal. Is played out.

場合 When the present technology is applied to the video processor 1332 configured as described above, the present technology according to each embodiment described above may be applied to the encoding / decoding engine 1407. That is, for example, the encoding / decoding engine 1407 may have the functions of the encoding device and the decoding device according to the first and second embodiments. In this way, the video processor 1332 can obtain the same effects as those described above with reference to FIGS.

In the encoding / decoding engine 1407, the present technology (that is, the functions of the image encoding device and the image decoding device according to each embodiment described above) may be realized by hardware such as a logic circuit. It may be realized by software such as an embedded program, or may be realized by both of them.

(Another configuration example of the video processor)
FIG. 53 illustrates another example of a schematic configuration of the video processor 1332 (FIG. 51) to which the present technology is applied. In the case of the example in FIG. 53, the video processor 1332 has a function of encoding and decoding video data by a predetermined method.

More specifically, as illustrated in FIG. 53, the video processor 1332 includes a control unit 1511, a display interface 1512, a display engine 1513, an image processing engine 1514, and an internal memory 1515. The video processor 1332 includes a codec engine 1516, a memory interface 1517, a multiplexing / demultiplexing unit (MUX DMUX) 1518, a network interface 1519, and a video interface 1520.

The eyelid control unit 1511 controls the operation of each processing unit in the video processor 1332 such as the display interface 1512, the display engine 1513, the image processing engine 1514, and the codec engine 1516.

As shown in FIG. 53, the control unit 1511 includes, for example, a main CPU 1531, a sub CPU 1532, and a system controller 1533. The main CPU 1531 executes a program and the like for controlling the operation of each processing unit in the video processor 1332. The main CPU 1531 generates a control signal according to the program and supplies it to each processing unit (that is, controls the operation of each processing unit). The sub CPU 1532 plays an auxiliary role of the main CPU 1531. For example, the sub CPU 1532 executes a child process such as a program executed by the main CPU 1531, a subroutine, or the like. The system controller 1533 controls operations of the main CPU 1531 and the sub CPU 1532 such as designating a program to be executed by the main CPU 1531 and the sub CPU 1532.

The display interface 1512 outputs image data to, for example, the connectivity 1321 (FIG. 51) or the like under the control of the control unit 1511. For example, the display interface 1512 converts the digital data image data into an analog signal, and outputs it to the monitor device of the connectivity 1321 (FIG. 51) as a reproduced video signal or as the digital data image data.

Under the control of the control unit 1511, the display engine 1513 performs various conversion processes such as format conversion, size conversion, color gamut conversion, and the like so as to match the image data with hardware specifications such as a monitor device that displays the image. I do.

The eyelid image processing engine 1514 performs predetermined image processing such as filter processing for improving image quality on the image data under the control of the control unit 1511.

The internal memory 1515 is a memory provided inside the video processor 1332 that is shared by the display engine 1513, the image processing engine 1514, and the codec engine 1516. The internal memory 1515 is used, for example, for data exchange performed between the display engine 1513, the image processing engine 1514, and the codec engine 1516. For example, the internal memory 1515 stores data supplied from the display engine 1513, the image processing engine 1514, or the codec engine 1516, and stores the data as needed (eg, upon request). This is supplied to the image processing engine 1514 or the codec engine 1516. The internal memory 1515 may be realized by any storage device, but is generally used for storing a small amount of data such as image data or parameters in units of blocks. It is desirable to realize a semiconductor memory having a relatively small capacity but a high response speed (for example, as compared with the external memory 1312) such as “Static Random Access Memory”.

The codec engine 1516 performs processing related to encoding and decoding of image data. The encoding / decoding scheme supported by the codec engine 1516 is arbitrary, and the number thereof may be one or plural. For example, the codec engine 1516 may be provided with codec functions of a plurality of encoding / decoding schemes, and may be configured to perform encoding of image data or decoding of encoded data using one selected from them.

In the example shown in FIG. 53, the codec engine 1516 includes, for example, MPEG-2 video 1541, AVC / H.2641542, HEVC / H.2651543, HEVC / H.265 (Scalable) 1544, as function blocks for processing related to the codec. HEVC / H.265 (Multi-view) 1545 and MPEG-DASH 1551 are included.

“MPEG-2” Video 1541 is a functional block that encodes and decodes image data in the MPEG-2 format. AVC / H.2641542 is a functional block that encodes and decodes image data using the AVC method. HEVC / H.2651543 is a functional block that encodes and decodes image data using the HEVC method. HEVC / H.265 (Scalable) 1544 is a functional block that performs scalable encoding and scalable decoding of image data using the HEVC method. HEVC / H.265 (Multi-view) 1545 is a functional block that multi-view encodes or multi-view decodes image data using the HEVC method.

“MPEG-DASH 1551” is a functional block that transmits and receives image data in the MPEG-DASH (MPEG-Dynamic Adaptive Streaming over HTTP) method. MPEG-DASH is a technology for streaming video using HTTP (HyperText Transfer Protocol), and selects and transmits appropriate data from multiple encoded data with different resolutions prepared in advance in segments. This is one of the features. MPEG-DASH 1551 generates a stream compliant with the standard, controls transmission of the stream, and the like. For encoding / decoding of image data, MPEG-2 Video 1541 to HEVC / H.265 (Multi-view) 1545 described above are used. Is used.

The memory interface 1517 is an interface for the external memory 1312. Data supplied from the image processing engine 1514 or the codec engine 1516 is supplied to the external memory 1312 via the memory interface 1517. The data read from the external memory 1312 is supplied to the video processor 1332 (the image processing engine 1514 or the codec engine 1516) via the memory interface 1517.

A multiplexing / demultiplexing unit (MUX DMUX) 1518 multiplexes and demultiplexes various data related to images such as a bit stream of encoded data, image data, and a video signal. This multiplexing / demultiplexing method is arbitrary. For example, at the time of multiplexing, the multiplexing / demultiplexing unit (MUX DMUX) 1518 can not only combine a plurality of data into one but also add predetermined header information or the like to the data. Further, in the demultiplexing, the multiplexing / demultiplexing unit (MUX DMUX) 1518 not only divides one data into a plurality of data but also adds predetermined header information or the like to each divided data. it can. That is, the multiplexing / demultiplexing unit (MUX DMUX) 1518 can convert the data format by multiplexing / demultiplexing. For example, the multiplexing / demultiplexing unit (MUX DMUX) 1518 multiplexes the bitstream, thereby transporting the transport stream, which is a bit stream in a transfer format, or data in a file format for recording (file data). Can be converted to Of course, the inverse transformation is also possible by demultiplexing.

The network interface 1519 is an interface for a broadband modem 1333, connectivity 1321 (both in FIG. 51), and the like. The video interface 1520 is an interface for connectivity 1321 and a camera 1322 (both of which are shown in FIG. 51), for example.

Next, an example of the operation of the video processor 1332 will be described. For example, when a transport stream is received from an external network via, for example, the connectivity 1321 or the broadband modem 1333 (both of which are shown in FIG. 51), the transport stream is transmitted to the multiplexing / demultiplexing unit (MUX) via the network interface 1519. DMUX) 1518 is demultiplexed and decoded by the codec engine 1516. For example, the image data obtained by decoding by the codec engine 1516 is subjected to predetermined image processing by the image processing engine 1514, subjected to predetermined conversion by the display engine 1513, and connected to, for example, the connectivity 1321 (see FIG. 51) etc., and the image is displayed on the monitor. Also, for example, image data obtained by decoding by the codec engine 1516 is re-encoded by the codec engine 1516, multiplexed by a multiplexing / demultiplexing unit (MUX DMUX) 1518, converted into file data, and video The data is output to, for example, the connectivity 1321 (FIG. 51) via the interface 1520 and recorded on various recording media.

Further, for example, encoded data file data obtained by encoding image data read from a recording medium (not shown) by the connectivity 1321 (FIG. 51) is multiplexed / demultiplexed via the video interface 1520. Is supplied to a unit (MUX DMUX) 1518, demultiplexed, and decoded by the codec engine 1516. Image data obtained by decoding by the codec engine 1516 is subjected to predetermined image processing by the image processing engine 1514, subjected to predetermined conversion by the display engine 1513, and, for example, connectivity 1321 (FIG. 51) via the display interface 1512. And the image is displayed on the monitor. Also, for example, image data obtained by decoding by the codec engine 1516 is re-encoded by the codec engine 1516, multiplexed by the multiplexing / demultiplexing unit (MUX DMUX) 1518, and converted into a transport stream, For example, the connectivity 1321 and the broadband modem 1333 (both in FIG. 51) are supplied via the network interface 1519 and transmitted to another device (not shown).

Note that image data and other data are exchanged between the processing units in the video processor 1332 using, for example, the internal memory 1515 and the external memory 1312. The power management module 1313 controls power supply to the control unit 1511, for example.

場合 When the present technology is applied to the video processor 1332 configured as described above, the present technology according to each of the above-described embodiments may be applied to the codec engine 1516. That is, for example, the codec engine 1516 may have a functional block that realizes the encoding device and the decoding device according to the first and second embodiments. With the codec engine 1516 doing in this way, the video processor 1332 can obtain the same effects as those described above with reference to FIGS.

Note that in the codec engine 1516, the present technology (that is, the functions of the image encoding device and the image decoding device according to each of the above-described embodiments) may be realized by hardware such as a logic circuit or an embedded program. It may be realized by software such as the above, or may be realized by both of them.

Although two examples of the configuration of the video processor 1332 have been described above, the configuration of the video processor 1332 is arbitrary and may be other than the two examples described above. The video processor 1332 may be configured as one semiconductor chip, but may be configured as a plurality of semiconductor chips. For example, a three-dimensional stacked LSI in which a plurality of semiconductors are stacked may be used. Further, it may be realized by a plurality of LSIs.

(Application example for equipment)
Video set 1300 can be incorporated into various devices that process image data. For example, the video set 1300 can be incorporated in the television device 900 (FIG. 44), the mobile phone 920 (FIG. 45), the recording / reproducing device 940 (FIG. 46), the imaging device 960 (FIG. 47), or the like. By incorporating the video set 1300, the apparatus can obtain the same effects as those described above with reference to FIGS.

The video set 1300 includes, for example, terminal devices such as the personal computer 1004, the AV device 1005, the tablet device 1006, and the mobile phone 1007 in the data transmission system 1000 in FIG. 48, the broadcasting station 1101 in the data transmission system 1100 in FIG. It can also be incorporated into the terminal device 1102, the imaging device 1201 in the imaging system 1200 of FIG. 50, the scalable encoded data storage device 1202, and the like. By incorporating the video set 1300, the apparatus can obtain the same effects as those described above with reference to FIGS.

Note that even a part of each configuration of the video set 1300 described above can be implemented as a configuration to which the present technology is applied as long as it includes the video processor 1332. For example, only the video processor 1332 can be implemented as a video processor to which the present technology is applied. Further, for example, as described above, the processor, the video module 1311 and the like indicated by the dotted line 1341 can be implemented as a processor or a module to which the present technology is applied. Furthermore, for example, the video module 1311, the external memory 1312, the power management module 1313, and the front end module 1314 can be combined and implemented as a video unit 1361 to which the present technology is applied. In any case, the same effects as those described above with reference to FIGS. 1 to 700 can be obtained.

That is, any configuration including the video processor 1332 can be incorporated into various devices that process image data, as in the case of the video set 1300. For example, a video processor 1332, a processor indicated by a dotted line 1341, a video module 1311, or a video unit 1361, a television device 900 (FIG. 44), a mobile phone 920 (FIG. 45), a recording / playback device 940 (FIG. 46), Imaging device 960 (FIG. 47), terminal devices such as personal computer 1004, AV device 1005, tablet device 1006, and mobile phone 1007 in data transmission system 1000 in FIG. 48, broadcast station 1101 and terminal in data transmission system 1100 in FIG. It can be incorporated in the apparatus 1102, the imaging apparatus 1201 in the imaging system 1200 of FIG. 50, the scalable encoded data storage apparatus 1202, and the like. Then, by incorporating any configuration to which the present technology is applied, the apparatus can obtain the same effects as those described above with reference to FIGS. 1 to 700 as in the case of the video set 1300. .

In the present specification, an example in which various types of information such as enlargement / reduction ratio information and enlargement / reduction ratio correspondence information are multiplexed with encoded data and transmitted from the encoding side to the decoding side has been described. However, the method for transmitting such information is not limited to such an example. For example, these pieces of information may be transmitted or recorded as separate data associated with the encoded data without being multiplexed with the encoded data. Here, the term “associate” means that an image (which may be a part of an image such as a slice or a block) included in the bitstream and information corresponding to the image can be linked at the time of decoding. Means. That is, the information may be transmitted on a transmission path different from the encoded data. The information may be recorded on a recording medium different from the encoded data (or another recording area of the same recording medium). Furthermore, the information and the encoded data may be associated with each other in an arbitrary unit such as a plurality of frames, one frame, or a part of the frame.

This disclosure receives bitstreams compressed by orthogonal transform such as discrete cosine transform and motion compensation, such as MPEG, H.26x, etc., via network media such as satellite broadcasting, cable TV, the Internet, and mobile phones. The present invention can be applied to an encoding device or a decoding device that is used when processing on a storage medium such as an optical, magnetic disk, or flash memory.

In addition, the present disclosure can also be applied to an encoding device and a decoding device of an encoding method other than the HEVC method that performs inter prediction processing.

In this specification, the system means a set of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Accordingly, a plurality of devices housed in separate housings and connected via a network and a single device housing a plurality of modules in one housing are all systems. .

Furthermore, the effects described in the present specification are merely examples and are not limited, and may have other effects.

The embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

For example, the present disclosure can take a cloud computing configuration in which one function is shared by a plurality of devices via a network and is processed jointly.

Further, each step described in the above flowchart can be executed by one device or can be shared by a plurality of devices.

Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

This disclosure can have the following configurations.

(1)
An enlargement / reduction unit that enlarges or reduces the reference image based on enlargement / reduction rate information indicating a rate of enlargement or reduction of the reference image with respect to the inter-coded image;
A generation unit that generates a predicted image using the reference image enlarged or reduced by the enlargement / reduction unit;
A decoding device comprising: a decoding unit that decodes the inter-coded image using the prediction image generated by the generation unit.
(2)
The enlargement / reduction unit is configured to generate one pixel in the reference image as a plurality of pixels constituting the predicted image when the enlargement / reduction ratio information represents an enlargement ratio. (1) The decoding device according to 1.
(3)
The enlargement / reduction unit is configured to generate one pixel in a region of the reference image as a pixel of a predicted image corresponding to the region when the enlargement / reduction rate represents a reduction rate. ) Or (2).
(4)
A filter processing unit that performs low pass filter processing on a block-by-block basis for the reference image enlarged or reduced by the enlargement / reduction unit;
The decoding device according to any one of (1) to (3), wherein the generation unit generates the prediction image using the reference image subjected to low-pass filter processing by the filter processing unit.
(5)
The decoding device according to (4), wherein the filter processing unit is configured to perform the low-pass filter processing on the reference image when a size of the block is smaller than a predetermined size.
(6)
The decoding device according to any one of (1) to (5), wherein the enlargement / reduction ratio information is configured to be set independently in a horizontal direction and a vertical direction of the inter-coded image.
(7)
The enlargement / reduction unit includes the enlargement / reduction ratio information for either the reference image before or after the inter-encoded image in the encoding order, the inter-encoded image, and the inter-encoded image. Any one of (1) to (6) configured to calculate the enlargement / reduction ratio information for the other based on the time distance between the previous reference image and the subsequent reference image in the encoding order. The decoding device according to 1.
(8)
Based on the difference between the enlargement / reduction rate information corresponding to the block of the predicted image and the enlargement / reduction rate information corresponding to the peripheral block that is a block around the block, and the enlargement / reduction rate information of the peripheral block The decoding device according to any one of (1) to (7), further including: an information decoding unit that determines the enlargement / reduction ratio information of the block of the predicted image.
(9)
When the motion vector encoding mode in the inter-encoded image is the merge mode, the enlargement / reduction rate information corresponding to the block of the predicted image to which the motion vector is referenced in the merge mode is displayed. The decoding device according to any one of (1) to (8), further including: a determination unit that determines the enlargement / reduction ratio information corresponding to a block.
(10)
The decryption device
An enlargement / reduction step for enlarging or reducing the reference image based on enlargement / reduction ratio information indicating a rate of enlargement or reduction of the reference image with respect to the inter-coded image;
Generating a predicted image using the reference image enlarged or reduced by the process of the enlargement / reduction step;
And a decoding step of decoding the inter-coded image using the prediction image generated by the processing of the generation step.
(11)
An enlargement / reduction unit that enlarges or reduces the reference image based on enlargement / reduction rate information indicating a rate of enlargement / reduction of the reference image with respect to the encoding target image;
A generation unit that generates a predicted image using the reference image enlarged or reduced by the enlargement / reduction unit;
An encoding unit that encodes the image to be encoded using the predicted image generated by the generation unit and generates encoded data;
An encoding apparatus comprising: a transmission unit that transmits the encoded data generated by the encoding unit and the enlargement / reduction ratio information.
(12)
The transmission unit is configured to transmit only the enlargement / reduction ratio information for either the reference image before or the reference image after the reference image in the encoding order from the image to be encoded (11) The encoding device described in 1.
(13)
An information encoding unit that calculates a difference between the enlargement / reduction rate information corresponding to the block of the predicted image and the enlargement / reduction rate information corresponding to a peripheral block that is a peripheral block of the block;
The encoding device according to (11) or (12), wherein the transmission unit is configured to transmit a difference between the enlargement / reduction rate information calculated by the information encoding unit.
(14)
When the motion vector encoding mode in the encoding target image is the merge mode, the enlargement / reduction rate information corresponding to the block of the prediction image to which the motion vector is referred in the merge mode is used as the reference source prediction image. A determination unit for determining the enlargement / reduction ratio information corresponding to the block of
The encoding device according to any one of (11) to (13), wherein the transmission unit transmits the enlargement / reduction rate information when an encoding mode of the motion vector is other than a merge mode.
(15)
The encoding device
An enlargement / reduction step for enlarging or reducing the reference image based on enlargement / reduction rate information indicating a rate of enlargement or reduction of the reference image with respect to the image to be encoded;
Generating a predicted image using the reference image enlarged or reduced by the process of the enlargement / reduction step;
Using the predicted image generated by the processing of the generating step, the encoding step of encoding the image to be encoded and generating encoded data;
An encoding method comprising: a transmission step of transmitting the encoded data generated by the processing of the encoding step and the enlargement / reduction ratio information.

10 encoding device, 13 transmission unit, 33 operation unit, 82 reference image buffer, 83 low pass filter, 84 generation unit, 84 decoding unit, 110 decoding unit, 135 addition unit, 145 information decoding unit, 162 reference image buffer, 163 low pass filter, 164 generation Part

Claims

An enlargement / reduction unit that enlarges or reduces the reference image based on enlargement / reduction rate information indicating a rate of enlargement or reduction of the reference image with respect to the inter-coded image;
A generation unit that generates a predicted image using the reference image enlarged or reduced by the enlargement / reduction unit;
A decoding device comprising: a decoding unit that decodes the inter-coded image using the prediction image generated by the generation unit.
The scaling unit is configured to generate one pixel in the reference image as a plurality of pixels constituting the predicted image when the scaling factor information represents a scaling factor. The decoding device described.
The scaling unit is configured to generate one pixel in a region of the reference image as a pixel of a predicted image corresponding to the region when the scaling factor information represents a reduction rate. The decoding device according to 1.
A filter processing unit that performs low pass filter processing on a block-by-block basis for the reference image enlarged or reduced by the enlargement / reduction unit;
The decoding device according to claim 1, wherein the generation unit generates the predicted image using the reference image that has been subjected to low-pass filter processing by the filter processing unit.
The decoding device according to claim 4, wherein the filter processing unit is configured to perform the low-pass filter processing on the reference image when a size of the block is smaller than a predetermined size.
The decoding apparatus according to claim 1, wherein the enlargement / reduction ratio information is configured to be set independently in a horizontal direction and a vertical direction of the inter-coded image.
The enlargement / reduction unit includes the enlargement / reduction ratio information for either the reference image before or after the inter-encoded image in the encoding order, the inter-encoded image, and the inter-encoded image. The decoding device according to claim 1, further configured to calculate the enlargement / reduction ratio information for the other based on the time distance between the previous reference image and the subsequent reference image in the encoding order.
Based on the difference between the enlargement / reduction rate information corresponding to the block of the predicted image and the enlargement / reduction rate information corresponding to the peripheral block that is a block around the block, and the enlargement / reduction rate information of the peripheral block The decoding apparatus according to claim 1, further comprising: an information decoding unit that determines the enlargement / reduction ratio information of the block of the predicted image.
When the motion vector encoding mode in the inter-encoded image is the merge mode, the enlargement / reduction rate information corresponding to the block of the predicted image to which the motion vector is referenced in the merge mode is displayed. The decoding device according to claim 1, further comprising: a determination unit that determines the enlargement / reduction ratio information corresponding to a block.
The decryption device
An enlargement / reduction step for enlarging or reducing the reference image based on enlargement / reduction ratio information indicating a rate of enlargement or reduction of the reference image with respect to the inter-coded image;
Generating a predicted image using the reference image enlarged or reduced by the process of the enlargement / reduction step;
And a decoding step of decoding the inter-coded image using the prediction image generated by the processing of the generation step.
An enlargement / reduction unit that enlarges or reduces the reference image based on enlargement / reduction rate information indicating a rate of enlargement / reduction of the reference image with respect to the encoding target image;
A generation unit that generates a predicted image using the reference image enlarged or reduced by the enlargement / reduction unit;
An encoding unit that encodes the image to be encoded using the predicted image generated by the generation unit and generates encoded data;
An encoding apparatus comprising: a transmission unit that transmits the encoded data generated by the encoding unit and the enlargement / reduction ratio information.
The transmission unit is configured to transmit only the enlargement / reduction ratio information for one of the previous reference image and the subsequent reference image in encoding order with respect to the encoding target image. The encoding device described.
An information encoding unit that calculates a difference between the enlargement / reduction rate information corresponding to the block of the predicted image and the enlargement / reduction rate information corresponding to a peripheral block that is a peripheral block of the block;
The encoding device according to claim 11, wherein the transmission unit is configured to transmit a difference between the enlargement / reduction rate information calculated by the information encoding unit.
When the motion vector encoding mode in the encoding target image is the merge mode, the enlargement / reduction rate information corresponding to the block of the prediction image to which the motion vector is referred in the merge mode is used as the reference source prediction image. A determination unit for determining the enlargement / reduction ratio information corresponding to the block of
The encoding device according to claim 11, wherein the transmission unit transmits the enlargement / reduction rate information when an encoding mode of the motion vector is other than a merge mode.
The encoding device
An enlargement / reduction step for enlarging or reducing the reference image based on enlargement / reduction rate information indicating a rate of enlargement or reduction of the reference image with respect to the image to be encoded;
Generating a predicted image using the reference image enlarged or reduced by the process of the enlargement / reduction step;
Using the predicted image generated by the processing of the generating step, the encoding step of encoding the image to be encoded and generating encoded data;
An encoding method comprising: a transmission step of transmitting the encoded data generated by the processing of the encoding step and the enlargement / reduction ratio information.