WO2014156705A1

WO2014156705A1 - Decoding device and decoding method, and encoding device and encoding method

Info

Publication number: WO2014156705A1
Application number: PCT/JP2014/056828
Authority: WO
Inventors: 佐藤　数史
Original assignee: ソニー株式会社
Priority date: 2013-03-26
Filing date: 2014-03-14
Publication date: 2014-10-02

Abstract

The present invention pertains to a decoding device and decoding method and an encoding device and encoding method, whereby intra-prediction modes for images having a hierarchical structure can be shared using a low processing load. A reception unit receives skip mode flags indicating that an intra-prediction mode for a base image is used as the intra-prediction mode for an enhancement image. An enhancement decoding unit uses the base image intra-prediction mode as the enhancement image intra-prediction mode, on the basis of the skip mode flag, and performs intra-prediction of the enhancement image. This disclosure can be applied, for example, to a decoding device.

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 and a decoding method that can share an intra prediction mode of an image having a hierarchical structure with a small amount of processing. The present invention also relates to an encoding apparatus and an encoding method.

In recent years, image information is handled as digital data, and MPEG (compressed by orthogonal transform such as discrete cosine transform and motion compensation is used for the purpose of efficient transmission and storage of information. A device compliant with a method such as Moving (Pictures Experts Group) phase) is becoming popular in both information distribution at broadcast stations and information reception in general households.

In particular, the MPEG2 (ISO / IEC 13818-2) system is defined as a general-purpose image encoding system, and is a standard that covers both interlaced and progressively scanned images, standard resolution images, and high-definition images. Widely used in a wide range of applications for consumer and consumer applications. By using the MPEG2 method, for example, a standard resolution interlaced scanning image having 720 × 480 pixels is 4 to 8 Mbps, and a high resolution interlaced scanning image having 1920 × 1088 pixels is 18 to 22 MBps. By assigning a (rate), 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 achieve higher encoding efficiency than the conventional encoding schemes such as MPEG2 and MPEG4, although a large amount of calculation is required for encoding and decoding.

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)).

Furthermore, as an extension, standardization of FRExt® (Fidelity Range Extension) including coding tools necessary for business such as RGB, YUV422, and YUV444, and 8 × 8DCT and quantization matrix specified by MPEG-2. 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, studies on improving the coding efficiency are continuing.

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

FIG. 1 is a diagram for explaining an HEVC intra prediction mode.

As shown in FIG. 1A, as the intra prediction mode of the AVC method, for each prediction block size, there are nine modes including a mode indicating eight directions and a direct current (DC) mode as a reference pixel direction with respect to the target pixel. is there. There are three types of luminance signal prediction block sizes: 4 × 4 pixels, 8 × 8 pixels, and 16 × 16 pixels. The size of the prediction block of the color difference signal is 16 × 16 pixels, and the intra prediction mode of the color difference signal can be defined independently of the luminance signal.

On the other hand, as shown in FIG. 1B, the HEVC intra prediction modes include a mode indicating 32 directions as a reference pixel direction with respect to a target pixel and 33 types of modes including a direct current mode. There are five types of predicted block sizes: 4 × 4 pixels, 8 × 8 pixels, 16 × 16 pixels, 32 × 32 pixels, and 64 × 64 pixels.

Thus, since the HEVC method has more types of intra prediction modes than the AVC method, the prediction accuracy is improved.

In addition, the HEVC intra prediction mode includes the Planer mode in addition to the 33 modes shown in FIG. In the Planer mode, each pixel in the prediction block is set as a target pixel, and among the already encoded pixels adjacent to the prediction block, pixels in the same row and column as the target pixel, and pixels in the upper right and lower left of the prediction block are used. This mode is used to generate predicted pixels by bi-linear interpolation.

For example, as illustrated in A of FIG. 2, when the upper left pixel 2 in the prediction block 1 of 8 × 8 pixels is the target pixel, the prediction pixel of the pixel 2 is the adjacent pixel 3 in the same row as the pixel 2. And the adjacent pixel 4 in the same column, and the upper right adjacent pixel 5 and the lower left adjacent pixel 6 of the prediction block 1 are generated.

2B, when the second pixel 7 from the left in the top row in the prediction block 1 is the target pixel, the prediction pixel of the pixel 7 is the same row as the pixel 7. Of adjacent pixels 3, adjacent pixels 8 in the same column, and

adjacent pixels

5 and 6.

Planar mode intra prediction can improve the coding efficiency of images with gradation.

FIG. 3 is a diagram for explaining a transmission method in the intra prediction mode in the HEVC scheme.

In the HEVC method, the intra prediction mode is predictively encoded and transmitted. Specifically, as illustrated in FIG. 3, first, the intra prediction modes of the prediction block 12 above the processing target prediction block 11 and the left prediction block 13 are set as intra prediction mode candidates MostProbableMode. Further, an intra prediction mode (Planar mode in the example of FIG. 3) determined by a combination of the intra prediction modes of the prediction block 12 and the prediction block 13 is set as a candidate MostProbableMode.

Then, when the intra prediction mode of the prediction block 11 is the same as one of the candidate MostProbableModes, an index that identifies the candidate MostProbableMode is transmitted as information indicating the intra prediction mode.

On the other hand, when the intra prediction mode of the prediction block 11 is different from any of the candidate MostProbableModes, 5-bit fixed-length information indicating the intra prediction mode is transmitted as information indicating the intra prediction mode.

When the intra prediction modes of the prediction block 12 and the prediction block 13 are the same, an intra prediction mode different from the actual intra prediction mode is set as the candidate MostProbableMode as one of the intra prediction modes. Thereby, compared with the case where the actual intra prediction mode is set to the candidate MostProbableMode, there is a higher possibility that the intra prediction mode of the prediction block 11 is the same as one of the candidate MostProbableModes, and the coding efficiency is improved.

By the way, image encoding methods such as MPEG-2 and AVC have a scalable function for encoding images by layering them. According to the scalable function, it is possible to transmit encoded data according to the processing capability on the decoding side without performing transcoding processing.

Specifically, for example, only a coded stream of an image of a base layer (base layer) that is a base layer can be transmitted to a terminal with low processing capability such as a mobile phone. On the other hand, an encoded stream of an image of a base layer and an enhancement layer (enhancement layer) that is a layer other than the base layer may be transmitted to a terminal having high processing capability such as a television receiver or a personal computer. it can.

HEVC version1 also has a scalable function (hereinafter referred to as temporal scalability) that encodes images by layering them at the frame rate.

Here, when encoding is performed using the scalable function, it is considered that the correlation regarding the intra prediction modes of the images of the base layer and the enhancement layer is high. Therefore, independently transmitting information indicating the intra prediction mode for the base layer and the enhancement layer transmits redundant information, which reduces coding efficiency.

Also, since the accuracy of the intra prediction mode of the base layer may be better than the intra prediction mode of the enhancement layer, there is a high possibility that the intra prediction mode of the enhancement layer is the same as the intra prediction mode of the base layer.

Therefore, it has been proposed to add the intra prediction mode of the base layer as one of enhancement layer candidates MostProbableMode (see, for example, Non-Patent Document 2). Thereby, when the intra prediction mode of a base layer and an enhancement layer is the same, it can prevent that both intra prediction modes are transmitted redundantly.

However, in the technique of Non-Patent Document 1, it is necessary to compare the candidate MostProbableMode including the intra prediction mode of the base layer with the intra prediction mode in all prediction blocks at the time of encoding, and the processing amount (computation amount) increases. .

The present disclosure has been made in view of such a situation, and makes it possible to share an intra prediction mode of an image having a hierarchical structure with a small processing amount.

A decoding device according to a first aspect of the present disclosure receives a mode information indicating that an intra prediction mode of an image of a first layer of an image having a hierarchical structure is used as an intra prediction mode of an image of a second layer. And the second layer image based on the mode information received by the receiving unit using the intra prediction mode of the first layer image as the intra prediction mode of the second layer image. It is a decoding apparatus provided with the intra prediction part which performs intra prediction of this.

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, mode information indicating that an intra prediction mode of an image of a first layer of an image having a hierarchical structure is used as an intra prediction mode of an image of a second layer is received and received. Based on the mode information, the intra prediction mode of the second layer image is performed using the intra prediction mode of the first layer image as the intra prediction mode of the second layer image.

The encoding device according to the second aspect of the present disclosure uses an intra prediction mode of an image of a first layer of an image having a hierarchical structure as an intra prediction mode of an image of a second layer. An intra prediction unit that performs intra prediction of an image; a setting unit that sets mode information indicating that an intra prediction mode of an image of the first layer is used as an intra prediction mode of an image of the second layer; and the setting A transmission unit that transmits the mode information set by the unit.

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, an intra prediction mode of an image of a first layer of an image having a hierarchical structure is used as an intra prediction mode of an image of a second layer, and the image of the second layer Intra prediction is performed, and mode information indicating that the intra prediction mode of the first layer image is used as the intra prediction mode of the second layer image is set and 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.

According to the present disclosure, it is possible to decode an encoded stream that shares an intra prediction mode of an image having a hierarchical structure with a small amount of processing.

According to the second aspect of the present disclosure, it is possible to share an intra prediction mode of an image having a hierarchical structure with a small amount of processing.

It is a figure explaining the intra prediction mode of HEVC system. It is a figure explaining Planer mode. It is a figure explaining the transmission method of the intra prediction mode in a HEVC system. It is a figure explaining spatial scalability. It is a figure explaining temporal scalability. It is a figure explaining SNR scalability. It is a block diagram which shows the structural example of one Embodiment of the encoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the enhancement encoding part of FIG. It is a block diagram which shows the structural example of the encoding part of FIG. It is a block diagram which shows the structural example of the intra estimation part of FIG. It is a figure explaining the prediction block of the enhancement image of a process target, and the prediction block of the collocated base image. It is a figure explaining CU. It is a figure which shows the example of the syntax of the encoding data of the CU unit of an enhancement image. It is a figure which shows the example of the syntax of the encoding data of the CU unit of an enhancement image. It is a flowchart explaining the hierarchical encoding process of the encoding apparatus of FIG. It is a flowchart explaining the detail of the enhancement encoding process of FIG. It is a flowchart explaining the detail of the enhancement encoding process of FIG. It is a flowchart explaining the detail of the intra prediction process of FIG. It is a block diagram which shows the structural example of one Embodiment of the decoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the enhancement decoding part of FIG. It is a block diagram which shows the structural example of the decoding part of FIG. It is a block diagram which shows the structural example of the intra estimation part of FIG. It is a flowchart explaining the hierarchical decoding process of the decoding apparatus of FIG. It is a flowchart explaining the detail of the enhancement decoding process of FIG. It is a flowchart explaining the detail of the intra prediction process of FIG. It is a figure which shows the example of a multiview image encoding system. It is a figure which shows the other example of encoding by a Scalable function. 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 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.

<Explanation of scalable function>
(Description of spatial scalability)
FIG. 4 is a diagram for explaining spatial scalability.

As shown in FIG. 4, spatial scalability is a scalable function that stratifies and encodes images with spatial resolution. Specifically, in spatial scalability, a low resolution image is encoded as a base layer image, and a difference image between the high resolution image and the low resolution image is encoded as an enhancement layer image.

Therefore, the encoding device transmits only the encoded data of the base layer image to the decoding device with low processing capability, so that the decoding device can generate a low-resolution image. Further, the encoding device transmits the encoded data of the base layer and enhancement layer images to the decoding device having high processing capability, so that the decoding device decodes and synthesizes the base layer and enhancement layer images. High-resolution images can be generated.

(Explanation of temporal scalability)
FIG. 5 is a diagram for explaining temporal scalability.

As described above, temporal scalability is a scalable function that encodes images by layering them at the frame rate. Specifically, as shown in FIG. 5, in temporal / scalability, for example, an image with a low frame rate (7.5 fps in the example of FIG. 5) is encoded as a base layer image. In addition, a difference image between the image at the medium frame rate (15 fps in the example of FIG. 5) and the image at the low frame rate is encoded as an enhancement layer image. Furthermore, the difference image between the image at the high frame rate (30 fps in the example of FIG. 5) and the image at the medium frame rate is encoded as an enhancement layer image.

Therefore, the encoding device transmits only the encoded data of the base layer image to the decoding device with low processing capability, so that the decoding device can generate a low frame rate image. Further, the encoding device transmits the encoded data of the base layer and enhancement layer images to the decoding device having high processing capability, so that the decoding device decodes and synthesizes the base layer and enhancement layer images. High frame rate or medium frame rate images can be generated.

(Description of SNR scalability)
FIG. 6 is a diagram illustrating SNR scalability.

As shown in FIG. 6, SNRabilityscalability is a scalable function that encodes an image layered with SNR (signal-noise ratio). Specifically, in SNR scalability, a low SNR image is encoded as a base layer image, and a difference image between a high SNR image and a low SNR image is encoded as an enhancement layer image.

Accordingly, the encoding device transmits only the encoded data of the base layer image to the decoding device with low processing capability, so that the decoding device can generate a low SNR image, that is, a low quality image. it can. Further, the encoding device transmits the encoded data of the base layer and enhancement layer images to the decoding device having high processing capability, so that the decoding device decodes and synthesizes the base layer and enhancement layer images. A high SNR image, that is, a high-quality image can be generated.

Although not shown, there are other scalable functions besides spatialsscalability, temporal scalability, and SNR scalability.

For example, as a scalable function, there is also bit-depth scalability for layering and encoding an image by the number of bits. In this case, for example, an 8-bit video image is used as a base layer image, and a difference between a 10-bit video image and an 8-bit video image is used as an enhancement layer image and encoded.

Also, as a scalable function, there is also a chroma-scalability for layering and encoding an image in a color difference signal format. In this case, for example, the YUV420 image is set as the base layer image, and the difference image between the YUV422 image and the YUV420 image is set as the enhancement layer image and encoded.

In the following, for convenience of explanation, a case where there is one enhancement layer will be described.

<First embodiment>
(Configuration example of one embodiment of encoding device)
FIG. 7 is a block diagram illustrating a configuration example of an embodiment of an encoding device to which the present disclosure is applied.

7 includes a base encoding unit 31, an enhancement encoding unit 32, a combining unit 33, and a transmission unit 34, and encodes an image using a scalable function in accordance with a scheme equivalent to the HEVC scheme.

A base layer image (hereinafter referred to as a base image) is input to the base encoding unit 31 of the encoding device 30 from the outside. The base encoding unit 31 is configured in the same manner as a conventional HEVC encoding device, and encodes a base image using the HEVC method. The base encoding unit 31 supplies an encoded stream including encoded data obtained as a result of encoding, SPS (Sequence Parameter Set), PPS (Picture Parameter Set), and the like to the synthesis unit 33 as a base stream. Further, the base encoding unit 31 supplies the intra prediction mode of the base image to the enhancement encoding unit 32.

The enhancement coding unit 32 receives an enhancement layer image (hereinafter referred to as an enhancement image) from the outside. The enhancement encoding unit 32 encodes the enhancement image by a method according to the HEVC method. At this time, the enhancement encoding unit 32 refers to the intra prediction mode from the base encoding unit 31 and performs an intra prediction process. The enhancement encoding unit 32 supplies an encoded stream including encoded data obtained as a result of encoding, SPS, PPS, and the like to the synthesizing unit 33 as an enhancement stream.

The synthesizing unit 33 synthesizes the base stream supplied from the base encoding unit 31 and the enhancement stream supplied from the enhancement encoding unit 32 to generate an encoded stream of all layers. The synthesis unit 33 supplies the encoded stream of all layers to the transmission unit 34.

The transmission unit 34 transmits the encoded stream of all layers supplied from the synthesis unit 33 to a decoding device to be described later.

In addition, although the encoding apparatus 30 shall transmit the encoding stream of all the layers here, it can also transmit only a base stream as needed.

(Configuration example of enhancement encoding unit)
FIG. 8 is a block diagram illustrating a configuration example of the enhancement encoding unit 32 of FIG.

The enhancement encoding unit 32 in FIG. 8 includes a setting unit 51 and an encoding unit 52.

The setting unit 51 of the enhancement encoding unit 32 sets parameter sets such as SPS, PPS, and VPS (Video Parameter Set) as necessary. The setting unit 51 supplies the set parameter set to the encoding unit 52.

The encoding unit 52 uses an enhancement image for each frame input from the outside as an input signal. The encoding unit 52 refers to the intra prediction mode from the base encoding unit 31 and encodes the input signal by a method according to the HEVC method. The encoding unit 52 generates an enhancement stream from the encoded data obtained as a result and the parameter set supplied from the setting unit 51, and supplies the enhancement stream to the synthesis unit 33 in FIG.

(Configuration example of encoding unit)
FIG. 9 is a block diagram illustrating a configuration example of the encoding unit 52 of FIG.

9 includes an A / D conversion unit 71, a screen rearrangement buffer 72, a calculation unit 73, an orthogonal transformation unit 74, a quantization unit 75, a lossless encoding unit 76, an accumulation buffer 77, a generation unit 78, Inverse quantization unit 79, inverse orthogonal transform unit 80, addition unit 81, deblock filter 82, adaptive offset filter 83, adaptive loop filter 84, frame memory 85, switch 86, intra prediction unit 87, motion prediction / compensation unit 88, The prediction image selection unit 89, the rate control unit 90, and the mode buffer 91 are configured.

The A / D conversion unit 71 of the encoding unit 52 performs A / D conversion on the enhancement image in units of frames input as an input signal, and outputs to the screen rearrangement buffer 72 for storage. The screen rearrangement buffer 72 rearranges the stored frame-by-frame enhancement images in the order for encoding according to the GOP structure, the arithmetic unit 73, the intra prediction unit 87, and the motion prediction / compensation. To the unit 88.

The calculation unit 73 performs encoding by calculating the difference between the predicted image supplied from the predicted image selection unit 89 and the encoding target image (enhancement image) output from the screen rearrangement buffer 72. Specifically, the calculation unit 73 performs encoding by subtracting the prediction image supplied from the prediction image selection unit 89 from the encoding target image output from the screen rearrangement buffer 72. The computing unit 73 outputs the resulting image to the orthogonal transform unit 74 as residual information. When the predicted image is not supplied from the predicted image selection unit 89, the calculation unit 73 outputs the image read from the screen rearrangement buffer 72 as it is to the orthogonal transform unit 74 as residual information.

The orthogonal transform unit 74 performs orthogonal transform on the residual information from the calculation unit 73 by a predetermined method, and supplies the generated orthogonal transform coefficient to the quantization unit 75.

The quantization unit 75 performs quantization on the orthogonal transform coefficient supplied from the orthogonal transform unit 74 and supplies the resulting coefficient to the lossless encoding unit 76.

The lossless encoding unit 76 acquires the intra prediction mode information and the skip mode flag from the intra prediction unit 87. The intra prediction mode information is information indicating the optimal intra prediction mode when the intra prediction mode (hereinafter referred to as the normal mode) other than the intra prediction mode of the base image (hereinafter referred to as the base mode) is the optimal intra prediction mode. . The skip mode flag is a flag indicating whether or not the base mode is used as the enhancement image intra prediction mode.

Also, the lossless encoding unit 76 acquires inter prediction mode information indicating an optimal inter prediction mode, a motion vector, reference image specifying information for specifying a reference image, and the like from the motion prediction / compensation unit 88. Further, the lossless encoding unit 76 acquires offset information from the adaptive offset filter 83 and acquires filter coefficients from the adaptive loop filter 84.

The lossless encoding unit 76 performs variable length coding (for example, CAVLC (Context-Adaptive Variable Length Coding)), arithmetic coding (for example, CABAC) on the quantized coefficients supplied from the quantization unit 75. (Context-Adaptive Binary Arithmetic Coding) etc.) is performed.

Further, the lossless encoding unit 76 uses the intra prediction mode information and the skip mode flag, or the inter prediction mode information, the motion vector, the reference image specifying information, the offset, and the filter coefficient as encoding information related to encoding. Turn into. The lossless encoding unit 76 supplies the encoded information and the lossless encoded coefficient to the storage buffer 77 as encoded data and stores them. Note that the losslessly encoded information may be added to the encoded data as a header portion.

The accumulation buffer 77 temporarily stores the encoded data supplied from the lossless encoding unit 76. Further, the accumulation buffer 77 supplies the stored encoded data to the generation unit 78.

The generating unit 78 generates an encoded stream from the parameter set supplied from the setting unit 51 in FIG. 8 and the encoded data supplied from the accumulation buffer 77, and supplies the encoded stream to the synthesizing unit 33 in FIG.

Also, the quantized coefficient output from the quantization unit 75 is also input to the inverse quantization unit 79. The inverse quantization unit 79 performs inverse quantization on the coefficient quantized by the quantization unit 75 and supplies the orthogonal transform coefficient obtained as a result to the inverse orthogonal transform unit 80.

The inverse orthogonal transform unit 80 performs the fourth-order inverse orthogonal transform on the orthogonal transform coefficient supplied from the inverse quantization unit 79 by a method corresponding to the orthogonal transform method in the orthogonal transform unit 74, and is obtained as a result. Residual information is supplied to the adder 81.

The addition unit 81 adds the residual information supplied from the inverse orthogonal transform unit 80 and the prediction image supplied from the prediction image selection unit 89 to obtain a locally decoded image. When the predicted image is not supplied from the predicted image selection unit 89, the adding unit 81 sets the residual information supplied from the inverse orthogonal transform unit 80 as a locally decoded image. The adder 81 supplies the locally decoded image to the deblock filter 82 and also supplies the image to the frame memory 85 for accumulation.

The deblocking filter 82 performs a deblocking filter process for removing block distortion on the locally decoded image supplied from the adding unit 81, and supplies the resulting image to the adaptive offset filter 83.

The adaptive offset filter 83 performs an adaptive offset filter (SAO (Sample adaptive offset)) process that mainly removes ringing on the image after the deblocking filter process supplied from the deblocking filter 82.

Specifically, the adaptive offset filter 83 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 83 performs the determined type of adaptive offset filter processing on the image after the deblocking filter processing, using the obtained offset. Then, the adaptive offset filter 83 supplies the image after the adaptive offset filter processing to the adaptive loop filter 84. The adaptive offset filter 83 supplies the type and offset of the adaptive offset process to the lossless encoding unit 76 as offset information.

The adaptive loop filter 84 is constituted by, for example, a two-dimensional Wiener filter. The adaptive loop filter 84 performs an adaptive loop filter (ALF (Adaptive Loop Filter)) process for each LCU, for example, on the image after the adaptive offset filter process supplied from the adaptive offset filter 83.

Specifically, the adaptive loop filter 84 is adapted so that the residual of the original image that is the image output from the screen rearrangement buffer 72 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 84 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 84 supplies the image after the adaptive loop filter processing to the frame memory 85. The adaptive loop filter 84 supplies the filter coefficient to the lossless encoding unit 76.

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 83 and the adaptive loop filter 84.

The frame memory 85 stores the image supplied from the adaptive loop filter 84 and the image supplied from the adder 81. The image stored in the frame memory 85 is output as a reference image to the intra prediction unit 87 or the motion prediction / compensation unit 88 via the switch 86.

The intra prediction unit 87 uses the reference image read from the frame memory 85 via the switch 86 to perform intra prediction in all candidate intra prediction modes. Also, the intra prediction unit 87 determines the candidate MostProbableMode as in the conventional case, and reads the base mode of the prediction block to be processed and the prediction block of the collocated base image from the mode buffer 91. In addition, collocated means that the position on the screen corresponds.

The intra prediction unit 87 generates information indicating each intra prediction mode based on each intra prediction mode, candidate MostProbableMode, and the read base mode.

The intra prediction unit 87 also selects all the intra prediction modes that are candidates based on the image read from the screen rearrangement buffer 72, the prediction image generated as a result of the intra prediction, information indicating the intra prediction mode, and the like. Cost function value (details will be described later). Then, the intra prediction unit 87 determines the intra prediction mode that minimizes the cost function value as the optimal intra prediction mode.

The intra prediction unit 87 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 89. The intra prediction unit 87 supplies the intra prediction mode information and the skip mode flag to the lossless encoding unit 76 as necessary when the prediction image selection unit 89 is notified of the selection of the prediction image generated in the optimal intra prediction mode. To do.

Note that the cost function value is also called RD (Rate Distortion) cost. It is calculated based on a method of either 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 represented 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 88 performs motion prediction / compensation processing for all candidate inter prediction modes. Specifically, the motion prediction / compensation unit 88 selects all the inter prediction modes that are candidates based on the image supplied from the screen rearrangement buffer 72 and the reference image read from the frame memory 85 via the switch 86. The motion vector is detected. The motion prediction / compensation unit 88 performs compensation processing on the reference image based on the detected motion vector, and generates a predicted image.

At this time, the motion prediction / compensation unit 88 calculates the cost function value for all candidate inter prediction modes based on the image and the predicted image supplied from the screen rearrangement buffer 72, and the cost function value. Is determined to be the optimal inter prediction mode. Then, the motion prediction / compensation unit 88 supplies the cost function value of the optimal inter prediction mode and the corresponding predicted image to the predicted image selection unit 89. In addition, when the prediction image selection unit 89 is notified of selection of a prediction image generated in the optimal inter prediction mode, the motion prediction / compensation unit 88 receives inter prediction mode information, a corresponding motion vector, reference image specifying information, and the like. It outputs to the lossless encoding part 76.

Based on the cost function values supplied from the intra prediction unit 87 and the motion prediction / compensation unit 88, the predicted image selection unit 89 has a smaller corresponding cost function value among the optimal intra prediction mode and the optimal inter prediction mode. Are determined as the optimum prediction mode. Then, the predicted image selection unit 89 supplies the predicted image in the optimal prediction mode to the calculation unit 73 and the addition unit 81. Further, the predicted image selection unit 89 notifies the intra prediction unit 87 or the motion prediction / compensation unit 88 of selection of the predicted image in the optimal prediction mode.

The rate control unit 90 controls the rate of the quantization operation of the quantization unit 75 based on the encoded data stored in the storage buffer 77 so that overflow or underflow does not occur.

The mode buffer 91 stores the base mode supplied from the base encoding unit 31 in FIG.

(Configuration example of intra prediction unit)
FIG. 10 is a block diagram illustrating a configuration example of the intra prediction unit 87 in FIG. 9.

10 includes a generation unit 111, a prediction unit 112, a calculation unit 113, a determination unit 114, and a buffer 115.

The generation unit 111 of the intra prediction unit 87 reads the intra prediction mode of the prediction block adjacent on the left and above the processing target prediction block from the buffer 115. The generation unit 111 generates three candidate MostProbableModes based on the read intra prediction mode, and supplies them to the prediction unit 112.

The prediction unit 112 includes a normal prediction unit 121 and a skip prediction unit 122, and reads the base mode of the prediction block to be processed and the prediction block of the collocated base image from the mode buffer 91 in FIG. The normal prediction unit 121 of the prediction unit 112 uses the reference image read out from the frame memory 85 of FIG. 9 via the switch 86 to perform intra prediction of normal modes other than the base mode among candidate intra prediction modes. I do.

Further, the normal prediction unit 121 generates information indicating the normal mode using the candidate MostProbableMode supplied from the generation unit 111 for each normal mode. Specifically, the normal prediction unit 121 compares the normal mode with the candidate MostProbableMode, and if the normal mode is the same as one of the candidate MostProbableModes, generates an index that identifies the candidate MostProbableMode as information indicating the normal mode. . On the other hand, when the normal mode is different from any of the candidate MostProbableModes, the normal prediction unit 121 generates 5-bit fixed-length information indicating the normal mode.

The normal prediction unit 121 supplies the prediction image generated by the intra prediction and information indicating the normal mode to the calculation unit 113.

The skip prediction unit 122 performs base mode intra prediction (Intra Skip Mode prediction) using the reference image read from the frame memory 85 via the switch 86. The skip prediction unit 122 supplies the prediction image generated by the intra prediction to the calculation unit 113.

The calculation unit 113 functions as a setting unit and, as a skip mode flag of the prediction image supplied from the

normal prediction unit

121, 0 indicating that the base mode is not used as the intra prediction mode of the enhancement image is CU that is a coding unit. Set in units of (Coding Unit). In addition, the calculation unit 113 sets 1 representing that the base mode is used as the intra prediction mode of the enhancement image for each CU as the skip mode flag of the prediction image supplied from the skip prediction unit 122.

Based on the information indicating the normal mode and the prediction image supplied from the normal prediction unit 121, the corresponding skip mode flag, and the image read from the screen rearrangement buffer 72, the calculation unit 113 calculates the cost function of the normal mode. Calculate the value. The calculation unit 113 supplies the calculated cost function value, predicted image, information indicating the normal mode, and the skip mode flag to the determination unit 114.

Further, the calculation unit 113 calculates the cost function value of the base mode based on the predicted image supplied from the skip prediction unit 122, the corresponding skip mode flag, and the image read from the screen rearrangement buffer 72. The calculation unit 113 supplies the calculated cost function value, predicted image, and skip mode flag to the determination unit 114.

The determination unit 114 selects, as the optimal intra prediction mode, the base mode or the normal mode in which the cost function value is minimum for each CU based on the cost function value supplied from the calculation unit 113.

For example, the determination unit 114 compares the sum of the cost function values in the CU unit in the base mode with the sum of the cost function values in the CU unit in the normal mode in which the cost function value is the smallest, and determines the smaller sum as the optimal intra Select as prediction mode. Then, the determination unit 114 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 89 in FIG.

When the prediction image selection unit 89 notifies the selection of the prediction image generated in the optimal intra prediction mode, the determination unit 114 supplies the skip mode flag to the lossless encoding unit 76. In this case, when the optimal intra prediction mode is the normal mode, the determination unit 114 supplies information indicating the normal mode to the lossless encoding unit 76 as intra prediction mode information.

(Explanation of prediction block of collocated base image)
FIG. 11 is a diagram for explaining a prediction block of an enhancement image to be processed and a prediction block of a collocated base image.

As shown in FIG. 11, the prediction block 141 of the enhancement image to be processed and the prediction block 142 of the collocated base image include the pixel 142 A of the base image whose position on the screen corresponds to the center pixel 141 A of the prediction block 141. It is a prediction block. Alternatively, the prediction block 142 is a prediction block including a base image pixel 142B whose position on the screen corresponds to the pixel 141B in the upper left of the prediction block 141.

Note that the base mode is not read from the mode buffer 91 when the prediction block of the enhancement image and the prediction block of the collocated base image do not exist because they are outside the image frame. Accordingly, the skip prediction unit 122 does not perform intra prediction, and the skip mode flag becomes 0.

In this case, the skip prediction unit 122 may perform intra prediction using the base mode of the prediction block of the collocated base image as the DC mode. For example, when there is no predicted block of the collocated base image of some prediction blocks in the CU of the enhancement image, the skip prediction unit 122 can perform intra prediction with the base mode of the prediction block as the DC mode.

(Description of coding unit)
FIG. 12 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.

CU is also called Coding Tree Block (CTB) and plays the same role as a macroblock in the AVC method. Specifically, the CU is divided into Prediction Unit (PU) that is a unit of intra prediction or inter prediction, or is divided into Transform Unit (TU) that is a unit of orthogonal transformation. However, the size of the CU is a square represented by a power-of-two pixel that is variable for each sequence. At present, in the HEVC system, it is possible to use 4 × 4 pixels and 8 × 8 pixels as well as 16 × 16 pixels and 32 × 32 pixels as the TU size.

In the example of FIG. 12, the size of the LCU that is the maximum size CU is 128, and the size of the SCU (Smallest® Coding Unit) that is the minimum size CU is 8. Therefore, the layer depth (depth) of a 2N × 2N size CU layered for each N is 0 to 4, and the number of layer depths is 5. Further, when the value of split_flag is 1, the 2N × 2N size CU is divided into N × N size CUs, which are one layer below.

∙ Information specifying the LCU and SCU sizes is included in the SPS. Details of the CU are described in Non-Patent Document 1.

(Example of syntax of encoded data of CU unit of enhancement image)
FIG. 13 and FIG. 14 are diagrams illustrating an example of syntax of encoded data of CU units of enhancement images.

As shown in the 22nd line of FIG. 13, in the encoded data of the enhancement image in the CU unit, when the optimal prediction mode is the intra prediction mode and the data is not PCM (Pulse Code Modulation) data, the skip mode flag ( intra_skip_mode_flag). As shown in the 23rd to 35th lines, when the skip mode flag is 0, intra prediction mode information is described.

(Description of processing of encoding device)
FIG. 15 is a flowchart illustrating the hierarchical encoding process of the encoding device 30 in FIG.

In FIG.15 S11, the base encoding part 31 of the encoding apparatus 30 encodes the base image input from the outside by a HEVC system, and produces | generates a base stream by adding a parameter set. Then, the base encoding unit 31 supplies the base stream to the synthesis unit 33.

In step S12, the base encoding unit 31 supplies the intra prediction mode of the base image to the enhancement encoding unit 32.

In step S13, the setting unit 51 (FIG. 8) of the enhancement encoding unit 32 sets a parameter set for the enhancement image. In step S14, the encoding unit 52 performs enhancement encoding processing for encoding an enhancement image input from the outside. Details of the enhancement encoding process will be described with reference to FIGS. 16 and 17 described later.

In step S15, the generation unit 78 (FIG. 9) of the encoding unit 52 generates an enhancement stream from the encoded data generated in step S14 and the parameter set supplied from the setting unit 51.

In step S16, the synthesizing unit 33 synthesizes the base stream supplied from the base encoding unit 31 and the enhancement stream supplied from the enhancement encoding unit 32 to generate an encoded stream of all layers. The synthesis unit 33 supplies the encoded stream of all layers to the transmission unit 34.

In step S17, the transmission unit 34 transmits the encoded stream of all layers supplied from the synthesis unit 33 to a decoding device to be described later.

FIGS. 16 and 17 are flowcharts illustrating details of the enhancement encoding process in step S14 of FIG.

16, the A / D conversion unit 71 of the encoding unit 52 performs A / D conversion on the enhancement image in units of frames input as an input signal, and outputs and stores the enhancement image in the screen rearrangement buffer 72.

In step S32, the screen rearrangement buffer 72 rearranges the enhancement images of the frames in the stored display order in the order for encoding according to the GOP structure. The screen rearrangement buffer 72 supplies the frame-based enhancement image after the rearrangement to the calculation unit 73, the intra prediction unit 87, and the motion prediction / compensation unit 88.

In step S33, the intra prediction unit 87 performs intra prediction processing for all candidate intra prediction modes. The details of this intra prediction process will be described with reference to FIG.

Also, the motion prediction / compensation unit 88 performs motion prediction / compensation processing for all candidate inter prediction modes. In addition, the motion prediction / compensation unit 88 calculates cost function values for all candidate inter prediction modes based on the enhancement image and the prediction image supplied from the screen rearrangement buffer 72, and the cost function value. Is determined to be the optimal inter prediction mode. Then, the motion prediction / compensation unit 88 supplies the cost function value of the optimal inter prediction mode and the corresponding predicted image to the predicted image selection unit 89.

In step S34, the prediction image selection unit 89 selects the optimal intra prediction mode or the optimal inter prediction mode based on the cost function values supplied from the intra prediction unit 87 and the motion prediction / compensation unit 88 by the process of step S33. The one with the smallest cost function value is determined as the optimum prediction mode. Then, the predicted image selection unit 89 supplies the predicted image in the optimal prediction mode to the calculation unit 73 and the addition unit 81.

In step S35, the predicted image selection unit 89 determines whether or not the optimal prediction mode is the optimal inter prediction mode. When it is determined in step S35 that the optimal prediction mode is the optimal inter prediction mode, the predicted image selection unit 89 notifies the motion prediction / compensation unit 88 of selection of the predicted image generated in the optimal inter prediction mode.

In step S36, the motion prediction / compensation unit 88 supplies the inter prediction mode information, the motion vector, and the reference image specifying information to the lossless encoding unit 76, and the process proceeds to step S38.

On the other hand, when it is determined in step S35 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 prediction image selection unit 89 performs prediction generated in the optimal intra prediction mode. The intra prediction unit 87 is notified of image selection.

In step S37, the determination unit 114 (FIG. 10) of the intra prediction unit 87 supplies the intra prediction mode information and the skip mode flag or only the skip mode flag to the lossless encoding unit 76.

Specifically, the determination unit 114 supplies intra prediction mode information and 0 as a skip mode flag when the optimal intra prediction mode is the normal mode, and supplies only 1 as a skip mode flag when the optimal intra prediction mode is the base mode. . Further, the determination unit 114 supplies the optimal intra prediction mode to the buffer 115 and stores it. Then, the process proceeds to step S38.

In step S38, the calculation unit 73 performs encoding by subtracting the prediction image supplied from the prediction image selection unit 89 from the enhancement image supplied from the screen rearrangement buffer 72. The computing unit 73 outputs the resulting image to the orthogonal transform unit 74 as residual information.

In step S39, the orthogonal transform unit 74 performs orthogonal transform on the residual information from the calculation unit 73 and supplies the resulting orthogonal transform coefficient to the quantization unit 75.

In step S40, the quantization unit 75 quantizes the coefficient supplied from the orthogonal transform unit 74, and supplies the coefficient obtained as a result to the lossless encoding unit 76 and the inverse quantization unit 79.

17, the inverse quantization unit 79 inversely quantizes the quantized coefficient supplied from the quantization unit 75, and supplies the orthogonal transform coefficient obtained as a result to the inverse orthogonal transform unit 80.

In step S42, the inverse orthogonal transform unit 80 performs inverse orthogonal transform on the orthogonal transform coefficient supplied from the inverse quantization unit 79, and supplies the residual information obtained as a result to the addition unit 81.

In step S43, the adding unit 81 adds the residual information supplied from the inverse orthogonal transform unit 80 and the predicted image supplied from the predicted image selecting unit 89, and obtains a locally decoded image. The adder 81 supplies the obtained image to the deblock filter 82 and also supplies it to the frame memory 85.

In step S44, the deblocking filter 82 performs a deblocking filtering process on the locally decoded image supplied from the adding unit 81. The deblocking filter 82 supplies the resulting image to the adaptive offset filter 83.

In step S45, the adaptive offset filter 83 performs adaptive offset filter processing on the image after the deblocking filter processing by the deblocking filter 82. Then, the adaptive offset filter 83 supplies the image after the adaptive offset filter processing to the adaptive loop filter 84. The adaptive offset filter 83 supplies the type and offset of the adaptive offset process to the lossless encoding unit 76 as offset information.

In step S46, the adaptive loop filter 84 performs an adaptive loop filter process for each LCU on the image supplied from the adaptive offset filter 83. The adaptive loop filter 84 supplies the resulting image to the frame memory 85. The adaptive loop filter 84 also supplies the filter coefficient used in the adaptive loop filter process to the lossless encoding unit 76.

In step S47, the frame memory 85 stores the image supplied from the adaptive loop filter 84 and the image supplied from the adder 81. The image stored in the frame memory 85 is output as a reference image to the intra prediction unit 87 or the motion prediction / compensation unit 88 via the switch 86.

In step S48, the lossless encoding unit 76 uses the intra prediction mode information and the skip mode flag, or the inter prediction mode information, the motion vector, the reference image specifying information, the offset information, and the filter coefficient as encoding information. Turn into.

In step S49, the lossless encoding unit 76 losslessly encodes the quantized coefficient supplied from the quantization unit 75. Then, the lossless encoding unit 76 generates encoded data from the encoding information that has been losslessly encoded in the process of step S 48 and the losslessly encoded coefficient, and supplies the encoded data to the accumulation buffer 77.

In step S50, the accumulation buffer 77 temporarily accumulates the encoded data supplied from the lossless encoding unit 76.

In step S51, the rate control unit 90 controls the quantization operation rate of the quantization unit 75 based on the encoded data stored in the storage buffer 77 so that overflow or underflow does not occur.

In step S52, the accumulation buffer 77 outputs the stored encoded data to the generation unit 78. And a process returns to step S14 of FIG. 15, and progresses to step S15.

In the encoding processing of FIGS. 16 and 17, in order to simplify the description, the intra prediction processing and the motion prediction / compensation processing are always performed, but in actuality, either one of them depends on the picture type or the like. Sometimes only.

FIG. 18 is a flowchart for explaining the details of the intra prediction process in step S33 of FIG.

In FIG.18 S71, the production | generation part 111 (FIG. 10) of the intra estimation part 87 reads the intra prediction mode of the prediction block adjacent to the prediction block of a process target from the buffer 115 on the left. In step S 72, the generation unit 111 generates three candidate MostProbableModes based on the read intra prediction mode, and supplies them to the prediction unit 112.

In step S73, the prediction unit 112 reads the base block of the processing target prediction block and the collocated base image from the mode buffer 91 of FIG.

In step S74, the normal prediction unit 121 performs intra prediction in a normal mode other than the base mode among the candidate intra prediction modes, using the reference image read from the frame memory 85 via the switch 86.

In step S75, the normal prediction unit 121 generates information indicating the normal mode using the candidate MostProbableMode supplied from the generation unit 111 for each normal mode. The normal prediction unit 121 supplies the prediction image generated by the intra prediction and information indicating the normal mode to the calculation unit 113.

In step S76, the skip prediction unit 122 performs base mode intra prediction using the reference image read from the frame memory 85 via the switch 86. The skip prediction unit 122 supplies the prediction image generated by the intra prediction to the calculation unit 113.

In step S77, the skip prediction unit 122 sets a skip mode flag of the predicted image. Specifically, the skip prediction unit 122 sets the skip mode flag of the prediction image supplied from the normal prediction unit 121 to 0, and sets the skip mode flag of the prediction image supplied from the skip prediction unit 122 to 1. .

In step S 78, the calculation unit 113 calculates the normal based on the information indicating the normal mode and the predicted image supplied from the normal prediction unit 121, the corresponding skip mode flag, and the image read from the screen rearrangement buffer 72. Calculate the cost function value of the mode. The calculation unit 113 supplies the calculated cost function value, predicted image, information indicating the normal mode, and the skip mode flag to the determination unit 114.

In step S79, based on the cost function value supplied from the calculation unit 113, the determination unit 114 determines a base mode or a normal mode that minimizes the cost function value as the optimal intra prediction mode for each CU. The determination unit 114 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 89 in FIG.

As described above, the encoding device 30 sets the intra skip mode to 1 when performing the intra prediction of the enhancement image using the base mode as the intra prediction mode of the enhancement image. Thereby, the intra prediction mode of a base image and an enhancement image can be shared. As a result, the intra prediction modes of the base image and the enhancement image are not transmitted redundantly, and the coding efficiency is improved.

In addition, since the number of candidate MostProbableModes is the same as the conventional one, the amount of processing (calculation amount) for comparing the intra prediction mode and the candidate MostProbableMode does not increase when generating the intra prediction mode information. Therefore, it can be said that the intra prediction mode of the base image and the enhancement image can be shared with a small amount of processing.

Also, the encoding device 30 transmits a skip mode flag in units of CUs. On the other hand, when the base mode is one of the candidate MostProbableModes, it is necessary to transmit the index of the candidate MostProbableMode specifying the base mode in units of prediction blocks as information indicating that the intra prediction mode is the base mode. is there. Therefore, the encoding apparatus 30 can improve encoding efficiency compared with the case where the base mode is one of the candidate MostProbableModes.

(Configuration example of one embodiment of decoding device)
FIG. 19 is a block diagram illustrating a configuration example of an embodiment of a decoding device to which the present disclosure is applied, which decodes an encoded stream of all layers transmitted from the encoding device 30 of FIG.

19 includes a receiving unit 161, a separating unit 162, a base decoding unit 163, and an enhancement decoding unit 164.

The receiving unit 161 receives the encoded stream of all layers transmitted from the encoding device 30 in FIG. 7 and supplies it to the separating unit 162.

The separating unit 162 separates the base stream from the encoded streams of all layers supplied from the receiving unit 161 and supplies the base stream to the base decoding unit 163, and separates the enhancement stream and supplies the enhancement stream to the enhancement decoding unit 164.

The base decoding unit 163 is configured in the same manner as a conventional HEVC decoding device, decodes the base stream supplied from the separation unit 162 using the HEVC method, and generates a base image. The base decoding unit 163 supplies the base mode to the enhancement decoding unit 164 and outputs the generated base image.

The enhancement decoding unit 164 decodes the enhancement stream supplied from the demultiplexing unit 162 by a method according to the HEVC method, and generates an enhancement image. At this time, the enhancement decoding unit 164 refers to the base mode supplied from the base decoding unit 163. The enhancement decoding unit 164 outputs the generated enhancement image.

(Configuration example of enhancement decoding unit)
FIG. 20 is a block diagram illustrating a configuration example of the enhancement decoding unit 164 of FIG.

The enhancement decoding unit 164 in FIG. 20 includes an extraction unit 181 and a decoding unit 182.

The extraction unit 181 of the enhancement decoding unit 164 extracts a parameter set and encoded data from the enhancement stream supplied from the separation unit 162 in FIG. 19 and supplies the extracted parameter set and encoded data to the decoding unit 182.

The decoding unit 182 refers to the base mode supplied from the base decoding unit 163 in FIG. 19, and decodes the encoded data supplied from the extraction unit 181 by a method according to the HEVC method. At this time, the decoding unit 182 refers to the parameter set supplied from the extraction unit 181 as necessary. The decoding unit 182 outputs an image obtained as a result of decoding as an enhancement image.

(Configuration example of decoding unit)
FIG. 21 is a block diagram illustrating a configuration example of the decoding unit 182 of FIG.

21 includes an accumulation buffer 201, a lossless decoding unit 202, an inverse quantization unit 203, an inverse orthogonal transform unit 204, an addition unit 205, a deblock filter 206, an adaptive offset filter 207, an adaptive loop filter 208, a screen arrangement, and the like. It comprises a replacement buffer 209, a D / A conversion unit 210, a frame memory 211, a switch 212, an intra prediction unit 213, a motion compensation unit 214, a switch 215, and a mode buffer 216.

The accumulation buffer 201 of the decoding unit 182 receives and accumulates encoded data from the extraction unit 181 of FIG. The accumulation buffer 201 supplies the accumulated encoded data to the lossless decoding unit 202.

The lossless decoding unit 202 performs lossless decoding such as variable length decoding and arithmetic decoding corresponding to the lossless encoding of the lossless encoding unit 76 of FIG. 9 on the encoded data from the accumulation buffer 201, Obtain quantized coefficients and encoding information. The lossless decoding unit 202 supplies the quantized coefficient to the inverse quantization unit 203. Further, the lossless decoding unit 202 supplies only intra prediction mode information and skip mode flag or skip mode flag as encoded information to the intra prediction unit 213, and moves motion vectors, inter prediction mode information, reference image specifying information, and the like. This is supplied to the compensation unit 214.

Also, the lossless decoding unit 202 instructs the switch 215 to select the intra prediction unit 213 when the encoded information does not include inter prediction mode information, and if the inter prediction mode information is included, the lossless decoding unit 202 instructs the switch 215 to select a motion compensation unit. The selection of 214 is instructed. The lossless decoding unit 202 supplies offset information as encoded information to the adaptive offset filter 207 and supplies filter coefficients to the adaptive loop filter 208.

The inverse quantization unit 203, the inverse orthogonal transform unit 204, the addition unit 205, the deblock filter 206, the adaptive offset filter 207, the adaptive loop filter 208, the frame memory 211, the switch 212, the intra prediction unit 213, and the motion compensation unit 214 9, an inverse quantization unit 79, an inverse orthogonal transform unit 80, an addition unit 81, a deblock filter 82, an adaptive offset filter 83, an adaptive loop filter 84, a frame memory 85, a switch 86, an intra prediction unit 87, and motion The same processing as that performed by the prediction / compensation unit 88 is performed, whereby the image is decoded.

Specifically, the inverse quantization unit 203 inversely quantizes the quantized coefficient from the lossless decoding unit 202 and supplies the orthogonal transform coefficient obtained as a result to the inverse orthogonal transform unit 204.

The inverse orthogonal transform unit 204 performs inverse orthogonal transform on the orthogonal transform coefficient from the inverse quantization unit 203. The inverse orthogonal transform unit 204 supplies residual information obtained as a result of the inverse orthogonal transform to the addition unit 205.

The addition unit 205 performs decoding by adding the residual information as the decoding target image supplied from the inverse orthogonal transform unit 204 and the prediction image supplied from the switch 215. The adding unit 205 supplies an image obtained as a result of decoding to the deblocking filter 206 and also supplies it to the frame memory 211. When the predicted image is not supplied from the switch 215, the adding unit 205 supplies the image that is the residual information supplied from the inverse orthogonal transform unit 204 to the deblocking filter 206 as an image obtained as a result of decoding, and It is supplied to the frame memory 211 and accumulated.

The deblocking filter 206 performs a deblocking filtering process on the image supplied from the adding unit 205 and supplies the resulting image to the adaptive offset filter 207.

The adaptive offset filter 207 performs adaptive offset filter processing on the image from the deblocking filter 206 for each LCU using the offset information supplied from the lossless decoding unit 202. The adaptive offset filter 207 supplies the image after the adaptive offset filter processing to the adaptive loop filter 208.

The adaptive loop filter 208 performs an adaptive loop filter process for each LCU on the image supplied from the adaptive offset filter 207 using the filter coefficient supplied from the lossless decoding unit 202. The adaptive loop filter 208 supplies the resulting image to the frame memory 211 and the screen rearrangement buffer 209.

The screen rearrangement buffer 209 stores the image supplied from the adaptive loop filter 208 in units of frames. The screen rearrangement buffer 209 rearranges the stored frame-by-frame images for encoding in the original display order and supplies them to the D / A conversion unit 210.

The D / A conversion unit 210 D / A converts the frame unit image supplied from the screen rearrangement buffer 209 and outputs it as an enhancement image. The frame memory 211 stores the image supplied from the adaptive loop filter 208 and the image supplied from the adding unit 205. The image stored in the frame memory 211 is read as a reference image and supplied to the intra prediction unit 213 or the motion compensation unit 214 via the switch 212.

When the skip mode flag supplied from the lossless decoding unit 202 is 0, the intra prediction unit 213 sets the optimal intra prediction mode indicated by the intra prediction mode information supplied together with the skip mode flag to the intra of the prediction block to be processed. Determine the prediction mode.

On the other hand, when the skip mode flag is 1, the intra prediction unit 213 reads the processing target prediction block and the base mode of the collocated prediction block from the mode buffer 216, and determines the intra prediction mode of the processing target prediction block.

The intra prediction unit 213 performs intra prediction of the determined intra prediction mode using the reference image read from the frame memory 211 via the switch 212. The intra prediction unit 213 supplies the prediction image generated as a result to the switch 215.

The motion compensation unit 214 reads the reference image specified by the reference image specifying information supplied from the lossless decoding unit 202 from the frame memory 211 via the switch 212. The motion compensation unit 214 performs motion compensation processing in the optimal inter prediction mode indicated by the inter prediction mode information supplied from the lossless decoding unit 202, using the motion vector and the reference image supplied from the lossless decoding unit 202. The motion compensation unit 214 supplies the predicted image generated as a result to the switch 215.

The switch 215 supplies the prediction image supplied from the intra prediction unit 213 to the addition unit 205 when the selection of the intra prediction unit 213 is instructed from the lossless decoding unit 202. On the other hand, when the selection of the motion compensation unit 214 is instructed from the lossless decoding unit 202, the switch 215 supplies the predicted image supplied from the motion compensation unit 214 to the addition unit 205.

The mode buffer 216 stores the base mode supplied from the base decoding unit 163 in FIG.

(Configuration example of intra prediction unit)
FIG. 22 is a block diagram illustrating a configuration example of the intra prediction unit 213 in FIG.

The intra prediction unit 213 in FIG. 22 includes a generation unit 231, a prediction unit 232, and a buffer 233.

Similarly to the generation unit 111 in FIG. 10, the generation unit 231 of the intra prediction unit 213 reads the intra prediction mode of the prediction block adjacent to the processing target prediction block above and to the left from the buffer 233 to generate a candidate MostProbableMode, This is supplied to the prediction unit 232.

The prediction unit 232 includes a normal prediction unit 241 and a skip prediction unit 242. When the skip mode flag from the lossless decoding unit 202 in FIG. 21 is 0, the normal prediction unit 241 predicts the intra prediction mode indicated by the intra prediction mode information supplied together with the skip mode flag for each CU. Decide on the intra prediction mode of the block.

Specifically, when the intra prediction mode information indicates the index of the candidate MostProbableMode, the normal prediction unit 241 selects the candidate MostProbableMode specified by the index from among the candidate MostProbableMode supplied from the generation unit 231. Determine the prediction mode. On the other hand, when the intra prediction mode information is 5-bit fixed length information indicating the normal mode, the normal prediction unit 241 determines the normal mode as the intra prediction mode to be processed.

Then, the normal prediction unit 241 performs intra prediction in the determined intra prediction mode using the reference image read out from the frame memory 211 of FIG. 21 via the switch 212, and generates a prediction image. The normal prediction unit 241 supplies the predicted image to the switch 215 in FIG. 21 and supplies the determined intra prediction mode to the buffer 233.

Further, when the skip mode flag is 1, the skip prediction unit 242 reads out the base mode of the prediction block to be processed and the prediction block of the collocated base image from the mode buffer 216 for each CU, and sets the intra prediction mode to be processed. To decide. When there is no prediction block of the collocated base image, the skip prediction unit 242 sets the base mode of the prediction block to the DC mode and determines the intra prediction mode to be processed as the DC mode.

Then, the skip prediction unit 242 performs intra prediction in the determined intra prediction mode using the reference image read out from the frame memory 211 via the switch 212, and generates a predicted image. The skip prediction unit 242 supplies the predicted image to the switch 215 and supplies the determined intra prediction mode to the buffer 233.

The buffer 233 stores the intra prediction mode supplied from the prediction unit 232.

(Description of processing of decoding device)
FIG. 23 is a flowchart for explaining the hierarchical decoding process of the decoding device 160 of FIG.

23, the reception unit 161 of the decoding device 160 receives the encoded stream of all layers transmitted from the encoding device 30 of FIG. 7 and supplies it to the separation unit 162.

In step S112, the separation unit 162 separates the base stream and the enhancement stream from the encoded stream of all layers. The separation unit 162 supplies the base stream to the base decoding unit 163 and supplies the enhancement stream to the enhancement decoding unit 164.

In step S113, the base decoding unit 163 decodes the base stream supplied from the separation unit 162 by the HEVC method, and generates a base image. At this time, the base decoding unit 163 supplies the base mode to the enhancement decoding unit 164. The base decoding unit 163 outputs the generated base image.

In step S114, the extraction unit 181 (FIG. 20) of the enhancement decoding unit 164 extracts the parameter set and the encoded data from the enhancement stream supplied from the separation unit 162.

In step S115, the decoding unit 182 refers to the base mode supplied from the base decoding unit 163, and performs enhancement decoding processing for decoding the encoded data supplied from the extraction unit 181 in a method according to the HEVC method. Details of the enhancement decoding process will be described with reference to FIG. Then, the process ends.

FIG. 24 is a flowchart for explaining the details of the enhancement decoding process in step S115 of FIG.

24, the accumulation buffer 201 (FIG. 21) of the enhancement decoding unit 182 receives and accumulates encoded data in units of frames from the extraction unit 181 of FIG. The accumulation buffer 201 supplies the accumulated encoded data to the lossless decoding unit 202.

In step S132, the lossless decoding unit 202 performs lossless decoding on the encoded data from the accumulation buffer 201 to obtain quantized coefficients and encoded information. The lossless decoding unit 202 supplies the quantized coefficient to the inverse quantization unit 203. Further, the lossless decoding unit 202 supplies intra prediction mode information and skip mode flag as coding information, or only the skip mode flag to the intra prediction unit 213, and includes motion vectors, inter prediction mode information, reference image specifying information, and the like. Is supplied to the motion compensation unit 214.

Further, the lossless decoding unit 202 instructs the switch 215 to select the intra prediction unit 213 when the encoded information does not include the inter prediction mode information. The selection of 214 is instructed. The lossless decoding unit 202 supplies offset information as encoded information to the adaptive offset filter 207 and supplies filter coefficients to the adaptive loop filter 208.

In step S133, the inverse quantization unit 203 inversely quantizes the quantized coefficient from the lossless decoding unit 202, and supplies the resulting orthogonal transform coefficient to the inverse orthogonal transform unit 204.

In step S134, the motion compensation unit 214 determines whether or not the inter prediction mode information is supplied from the lossless decoding unit 202. 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 motion compensation unit 214 reads the reference image based on the reference image specifying information supplied from the lossless decoding unit 202, and uses the motion vector and the reference image to determine the optimal inter prediction mode indicated by the inter prediction mode information. Perform motion compensation processing. The motion compensation unit 214 supplies the predicted image generated as a result to the addition unit 205 via the switch 215, and the process proceeds to step S137.

On the other hand, when it is determined in step S134 that the inter prediction mode information is not supplied, that is, when the intra prediction mode information and the skip mode flag, or only the skip mode flag is supplied to the intra prediction unit 213, the process is step. The process proceeds to S136.

In step S136, the intra prediction unit 213 performs an intra prediction process using the reference image and the base mode read from the frame memory 211 via the switch 212. Details of this intra prediction process will be described with reference to FIG. After the intra prediction process, the process proceeds to step S137.

In step S137, the inverse orthogonal transform unit 204 performs inverse orthogonal transform on the orthogonal transform coefficient from the inverse quantization unit 203, and supplies the residual information obtained as a result to the addition unit 205.

In step S138, the adding unit 205 adds the residual information supplied from the inverse orthogonal transform unit 204 and the prediction image supplied from the switch 215. The adding unit 205 supplies the image obtained as a result to the deblocking filter 206 and also supplies it to the frame memory 211.

In step S139, the deblocking filter 206 performs deblocking filtering on the image supplied from the adding unit 205 to remove block distortion. The deblocking filter 206 supplies the resulting image to the adaptive offset filter 207.

In step S140, the adaptive offset filter 207 refers to the offset information supplied from the lossless decoding unit 202 with respect to the image from the deblocking filter 206, and performs adaptive offset filter processing for each LCU.

In step S141, the adaptive loop filter 208 performs an adaptive loop filter process for each LCU on the image supplied from the adaptive offset filter 207 using the filter coefficient supplied from the lossless decoding unit 202. The adaptive loop filter 208 supplies the resulting image to the frame memory 211 and the screen rearrangement buffer 209.

In step S142, the frame memory 211 stores the image supplied from the adding unit 205 and the image supplied from the adaptive loop filter 208. The image stored in the frame memory 211 is supplied to the intra prediction unit 213 or the motion compensation unit 214 via the switch 212 as a reference image.

In step S143, the screen rearrangement buffer 209 stores the image supplied from the adaptive loop filter 208 in units of frames, and rearranges the stored frame-by-frame images for encoding in the original display order. To the D / A converter 210.

In step S144, the D / A conversion unit 210 D / A converts the frame unit image supplied from the screen rearrangement buffer 209, and outputs it as an enhancement image. Then, the process returns to step S115 in FIG. 23 and ends.

FIG. 25 is a flowchart for explaining the details of the intra prediction process in step S136 of FIG.

In step S161, the generation unit 231 (FIG. 22) of the intra prediction unit 213 reads the intra prediction mode of the prediction block adjacent to the processing target prediction block above and to the left from the buffer 233. In step S 162, the generation unit 231 generates a candidate MostProbableMode using the read intra prediction mode and supplies the candidate MostProbableMode to the prediction unit 232.

In step S163, the normal prediction unit 241 of the prediction unit 232 determines whether or not the skip mode flag supplied from the lossless decoding unit 202 in FIG. If it is determined in step S163 that the skip mode flag is 0, the process proceeds to step S164.

In step S164, the normal prediction unit 241 determines the intra prediction mode indicated by the intra prediction mode information supplied together with the skip mode flag as the intra prediction mode of the prediction block to be processed.

In step S165, the normal prediction unit 241 performs intra prediction in the determined intra prediction mode using the reference image read out from the frame memory 211 of FIG. 21 via the switch 212, and generates a predicted image. The normal prediction unit 241 supplies the predicted image to the switch 215 in FIG. Then, the process proceeds to step S168.

On the other hand, if it is determined in step S163 that the skip mode flag is not 0, that is, if the skip mode flag is 1, the process proceeds to step S166.

In step S166, the skip prediction unit 242 reads out the base mode of the prediction block to be processed and the prediction block of the collocated base image from the mode buffer 216 in FIG. 21, and determines the intra prediction mode to be processed.

In step S167, the skip prediction unit 242 performs the intra prediction of the base mode determined as the intra prediction mode to be processed using the reference image read from the frame memory 211 via the switch 212, and obtains the predicted image. Generate. The skip prediction unit 242 supplies the predicted image to the switch 215.

In step S168, the prediction unit 232 supplies the intra prediction mode to be processed to the buffer 233 and stores it.

As described above, the decoding device 160 performs intra prediction of an enhancement image using the base mode based on the skip mode flag. Therefore, it is possible to decode an encoded stream that shares the intra prediction mode of the base image and the enhancement image with a small amount of processing.

In the first embodiment, the skip mode flag is transmitted in units of CUs. However, the skip mode flag may be transmitted in units of PUs, CU units larger than a predetermined size, LCU units, and the like. Good. When the skip mode flag is transmitted in units of CU larger than a predetermined size, information on the size is set in the VPS or the like.

In the first embodiment, the number of layers is two, but the number of layers may be two or more.

Furthermore, in the first embodiment, the base image is encoded by the HEVC method, but may be encoded by the AVC method. When the base image is encoded by the AVC method, the base mode is converted into the HEVC method intra prediction mode in the corresponding direction, and is used for the intra prediction process of the enhancement image. That is, the base mode is converted into the HEVC intra prediction mode in which the angle of the reference pixel relative to the target pixel and the angle of the reference direction are the same, and the angle of the reference pixel relative to the target pixel and the angle of the reference direction are the same. The enhancement image intra prediction mode is set.

In addition, when the base mode is the DC mode, the base mode is converted into the HEVC DC mode, and is set as the enhancement image intra prediction mode. When the base mode is the plain mode, the base mode is converted into the HEVC system Planar mode, and is set as the enhancement image intra prediction mode.

Also, sharing of the intra prediction mode of the base image and the enhancement image can be performed separately for both the luminance signal and the color difference signal.

<Application to multi-view image point 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. 26 shows an example of the multi-view image encoding method.

26, the multi-viewpoint image includes a plurality of viewpoint images, and a predetermined one viewpoint image among the plurality of viewpoints is designated as the base view image. Each viewpoint image other than the base view image is treated as a non-base view image. When multi-viewpoint image encoding is performed by the Scalable function, a base view image is encoded as a base layer image, and a non-base view image is encoded as an enhancement image.

When performing multi-view image coding as shown in FIG. 26, the difference between quantization parameters can be taken in each view (same view):
(1) base-view:
(1-1) dQP (base view) = Current_CU_QP (base view)-LCU_QP (base view)
(1-2) dQP (base view) = Current_CU_QP (base view)-Previsous_CU_QP (base view)
(1-3) dQP (base view) = Current_CU_QP (base view)-Slice_QP (base view)
(2) non-base-view:
(2-1) dQP (non-base view) = Current_CU_QP (non-base view)-LCU_QP (non-base view)
(2-2) dQP (non-base view) = Current QP (non-base view)-Previsous QP (non-base view)
(2-3) dQP (non-base view) = Current_CU_QP (non-base view)-Slice_QP (non-base view)

When performing multi-view image coding, it is also possible to take quantization parameter differences in each view (different views):
(3) base-view / non-base view:
(3-1) dQP (inter-view) = Slice_QP (base view)-Slice_QP (non-base view)
(3-2) dQP (inter-view) = LCU_QP (base view)-LCU_QP (non-base view)
(4) non-base view / non-base view:
(4-1) dQP (inter-view) = Slice_QP (non-base view i) −Slice_QP (non-base view j)
(4-2) dQP (inter-view) = LCU_QP (non-base view i)-LCU_QP (non-base view j)

In this case, the above (1) to (4) can be used in combination. For example, in the non-base view, a method of obtaining a quantization parameter difference at the slice level between the base view and the non-base view (combining 3-1 and 2-3), between the base view and the non-base view The method of taking the difference of the quantization parameter at the LCU level (combining 3-2 and 2-1) can be considered. Thus, by applying the difference repeatedly, the encoding efficiency can be improved even when multi-viewpoint encoding is performed.

Similarly to the method described above, a flag for identifying whether or not there is a dQP whose value is not 0 can be set for each of the above dQPs.

<Other examples of encoding using the Scalable function>
FIG. 27 shows another example of encoding by the Scalable function.

As shown in FIG. 27, in the encoding by the Scalable function, the difference of the quantization parameter can be taken in each layer (same layer):
(1) base-layer:
(1-1) dQP (base layer) = Current_CU_QP (base layer)-LCU_QP (base layer)
(1-2) dQP (base layer) = Current_CU_QP (base layer)-Previsous_CU_QP (base layer)
(1-3) dQP (base layer) = Current_CU_QP (base layer)-Slice_QP (base layer)
(2) non-base-layer:
(2-1) dQP (non-base layer) = Current_CU_QP (non-base layer)-LCU_QP (non-base layer)
(2-2) dQP (non-base layer) = Current QP (non-base layer)-Previsous QP (non-base layer)
(2-3) dQP (non-base layer) = Current_CU_QP (non-base layer) −Slice_QP (non-base layer)

It is also possible to take quantization parameter differences in each layer (different layers):
(3) base-layer / non-base layer:
(3-1) dQP (inter-layer) = Slice_QP (base layer)-Slice_QP (non-base layer)
(3-2) dQP (inter-layer) = LCU_QP (base layer)-LCU_QP (non-base layer)
(4) non-base layer / non-base layer:
(4-1) dQP (inter-layer) = Slice_QP (non-base layer i) −Slice_QP (non-base layer j)
(4-2) dQP (inter-layer) = LCU_QP (non-base layer i)-LCU_QP (non-base layer j)

In this case, the above (1) to (4) can be used in combination. For example, in the non-base layer, a method of obtaining a difference in quantization parameter at the slice level between the base layer and the non-base layer (combining 3-1 and 2-3), between the base layer and the non-base layer The method of taking the difference of the quantization parameter at the LCU level (combining 3-2 and 2-1) can be considered. In this manner, by applying the difference repeatedly, the encoding efficiency can be improved even when hierarchical encoding is performed.

<Second 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. 28 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, a CPU (Central Processing Unit) 601, a ROM (Read Only Memory) 602, and a RAM (Random Access Memory) 603 are connected to each other via a bus 604.

An input / output interface 605 is further connected to the bus 604. An input unit 606, an output unit 607, a storage unit 608, a communication unit 609, and a drive 610 are connected to the input / output interface 605.

The input unit 606 includes a keyboard, a mouse, a microphone, and the like. The output unit 607 includes a display, a speaker, and the like. The storage unit 608 includes a hard disk, a nonvolatile memory, and the like. The communication unit 609 includes a network interface or the like. The drive 610 drives a removable medium 611 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

In the computer configured as described above, the CPU 601 loads the program stored in the storage unit 608 to the RAM 603 via the input / output interface 605 and the bus 604 and executes the program, for example. Is performed.

The program executed by the computer (CPU 601) can be provided by being recorded on a removable medium 611 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, the program can be installed in the storage unit 608 via the input / output interface 605 by attaching the removable medium 611 to the drive 610. Further, the program can be received by the communication unit 609 via a wired or wireless transmission medium and installed in the storage unit 608. In addition, the program can be installed in the ROM 602 or the storage unit 608 in advance.

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

<Third Embodiment>
(Example configuration of television device)
FIG. 29 illustrates a schematic configuration of a television device to which the present disclosure 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 shares an intra prediction mode of an image having a hierarchical structure with a small amount of processing.

<Fourth embodiment>
(Configuration example of mobile phone)
FIG. 30 illustrates a schematic configuration of a mobile phone to which the present disclosure 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 to 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 medium such as a semiconductor memory such as a RAM or a built-in flash memory, a hard disk, a magnetic disk, a magneto-optical disk, an optical disk, a USB 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 share the intra prediction mode of an image having a hierarchical structure with a small processing amount. Also, it is possible to decode an encoded stream that shares an intra prediction mode of an image having a hierarchical structure with a small amount of processing.

<Fifth embodiment>
(Configuration example of recording / reproducing apparatus)
FIG. 31 illustrates a schematic configuration of a recording / reproducing apparatus to which the present disclosure 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 shares an intra prediction mode of an image having a hierarchical structure with a small amount of processing.

<Sixth embodiment>
(Configuration example of imaging device)
FIG. 32 illustrates a schematic configuration of an imaging apparatus to which the present disclosure 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 872, a camera signal processing unit 873, an image data processing unit 874, a display unit 875, an external interface unit 876, a memory unit 877, a media drive 968, an OSD unit 879, 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 874, the external interface unit 876, the memory unit 877, the media drive 968, the OSD unit 879, 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 872. The imaging unit 872 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 873.

The camera signal processing unit 873 performs various camera signal processing such as knee correction, gamma correction, and color correction on the electrical signal supplied from the imaging unit 872. The camera signal processing unit 873 supplies the image data after the camera signal processing to the image data processing unit 874.

The image data processing unit 874 performs an encoding process on the image data supplied from the camera signal processing unit 873. The image data processing unit 874 supplies the encoded data generated by performing the encoding process to the external interface unit 876 and the media drive 968. The image data processing unit 874 performs a decoding process on the encoded data supplied from the external interface unit 876 or the media drive 968. The image data processing unit 874 supplies the image data generated by performing the decoding process to the display unit 875. The image data processing unit 874 also superimposes the display data acquired from the OSD unit 879 on the display unit 875 by superimposing the display data acquired from the OSD unit 879 on the display unit 875, the image data supplied from the camera signal processing unit 873. To supply.

The OSD unit 879 generates display data such as a menu screen or an icon made up of symbols, characters, or figures and outputs it to the image data processing unit 874.

The external interface unit 876 includes, for example, a USB input / output terminal and the like, and is connected to a printer when printing an image. In addition, a drive is connected to the external interface unit 876 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 876 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 876. it can. In addition, the control unit 970 may acquire encoded data and image data supplied from another device via a network via the external interface unit 876 and supply the acquired data to the image data processing unit 874. 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 877 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 877 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 device configured as described above, the image data processing unit 874 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 share the intra prediction mode of an image having a hierarchical structure with a small processing amount. An encoded stream sharing an intra prediction mode of an image having a hierarchical structure can be decoded with a small amount of processing.

<Application example of scalable coding>
(First system)
Next, a specific use example of scalable encoded data that has been subjected to scalable encoding (hierarchical encoding), which is encoding by a scalable function, will be described. Scalable encoding is used for selection of data to be transmitted, as in the example shown in FIG. 33, for example.

In the data transmission system 1000 shown in FIG. 33, 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)
Further, scalable coding is used for transmission via a plurality of communication media as in the example shown in FIG. 34, for example.

34, 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)
Further, scalable encoding is used for storing encoded data as in the example shown in FIG. 35, for example.

In the imaging system 1200 illustrated in FIG. 35, the imaging device 1201 performs scalable coding on image data obtained by imaging the subject 1211, and as scalable coded data (BL + EL) 1221, 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.

In the present specification, an example in which various information such as the skip mode flag is multiplexed in the encoded stream 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 bitstream without being multiplexed into the encoded bitstream. 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, information may be transmitted on a transmission path different from that of the image (or bit stream). Information may be recorded on a recording medium (or another recording area of the same recording medium) different from the image (or bit stream). Furthermore, the information and the image (or bit stream) 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, in this specification, the case where encoding and decoding are performed by a method according to the HEVC method has been described as an example, but the scope of application of the present disclosure is not limited thereto. The present invention can be applied to other types of encoding devices and decoding devices as long as the encoding device performs encoding having a Scalable function and a corresponding decoding device.

Note that 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.

In addition, this indication can also take the following structures.

(1)
A receiving unit that receives mode information indicating that an intra prediction mode of an image of a first layer of an image having a hierarchical structure is used as an intra prediction mode of an image of a second layer;
Based on the mode information received by the receiving unit, the intra prediction mode of the second layer image is used using the intra prediction mode of the first layer image as the intra prediction mode of the second layer image. A decoding device comprising: an intra prediction unit that performs prediction.
(2)
The intra prediction unit, based on the mode information, sets an intra prediction mode of a prediction block of the first layer image collocated with a prediction block of the second layer image of the second layer image. The decoding device according to (1), wherein intra prediction is performed as an intra prediction mode of a prediction block.
(3)
The intra-prediction unit sets the intra prediction mode of the prediction block of the first layer image to DC when there is no collocated prediction block of the first layer image and the prediction block of the first layer image. The decoding device according to (2), wherein the mode is set.
(4)
The receiving unit receives the mode information of a coding unit;
The decoding device according to any one of (1) to (3), wherein the intra prediction unit performs intra prediction of the second layer image in the coding unit based on the mode information of the coding unit.
(5)
The receiving unit receives the mode information in units of prediction blocks,
The decoding device according to any one of (1) to (3), wherein the intra prediction unit performs intra prediction of the image of the second layer in the prediction block unit based on the mode information in the prediction block unit.
(6)
The receiving unit receives the mode information of a maximum coding unit;
The intra prediction unit performs intra prediction of the image of the second layer in the maximum encoding unit based on the mode information of the maximum encoding unit. Any one of (1) to (3) Decoding device.
(7)
The receiving unit receives the mode information of an encoding unit of a predetermined size and size information indicating the predetermined size;
The intra prediction unit performs intra prediction of the second layer image in the encoding unit of the predetermined size based on the mode information of the encoding unit of the predetermined size and the size information. (3) The decoding device according to any one of the above.
(8)
In the intra prediction unit, the encoding method of the first layer image is an AVC (Advanced Video Coding) method, and the encoding method of the second layer image is a HEVC (High Efficiency Video Coding) method. In this case, based on the mode information, the AVC intra prediction mode of the first layer image is converted into an HEVC intra prediction mode having the same angle as the corresponding angle, and the second layer image is converted. The decoding device according to any one of (1) to (7).
(9)
In the intra prediction unit, the encoding method of the first layer image is an AVC (Advanced Video Coding) method, and the encoding method of the second layer image is a HEVC (High Efficiency Video Coding) method. In this case, based on the mode information, the Plain mode as the intra prediction mode of the first layer image is converted into the HEVC Planar mode to obtain the intra prediction mode of the second layer image (1 ) To (8).
(10)
The decryption device
Receiving the mode information indicating that the intra prediction mode of the first layer image of the image having the hierarchical structure is used as the intra prediction mode of the second layer image;
Based on the mode information received by the processing of the receiving step, the intra prediction mode of the image of the first layer is used as the intra prediction mode of the image of the second layer, and the image of the second layer An intra prediction step for performing intra prediction of.
(11)
An intra prediction unit that performs intra prediction of an image of the second hierarchy using an intra prediction mode of an image of the first hierarchy of an image having a hierarchical structure as an intra prediction mode of an image of the second hierarchy;
A setting unit that sets mode information indicating that the intra prediction mode of the first layer image is used as the intra prediction mode of the second layer image;
A transmission unit configured to transmit the mode information set by the setting unit.
(12)
The intra prediction unit uses an intra prediction mode of a prediction block of an image of the first layer collocated with a prediction block of the image of the second layer as an intra prediction mode of a prediction block of the image of the second layer. The encoding device according to (11), wherein intra coding is performed.
(13)
The intra-prediction unit sets the intra prediction mode of the prediction block of the first layer image to DC when there is no collocated prediction block of the first layer image and the prediction block of the first layer image. The encoding apparatus according to (12), in which the mode is set.
(14)
The intra prediction unit performs intra prediction of the second layer image in a coding unit,
The encoding unit according to any one of (11) to (13), wherein the setting unit sets the mode information in the encoding unit.
(15)
The intra prediction unit performs intra prediction of the second layer image in prediction block units,
The encoding unit according to any one of (11) to (13), wherein the setting unit sets the mode information in units of the prediction block.
(16)
The intra prediction unit performs intra prediction of the second layer image in a maximum coding unit;
The encoding unit according to any one of (11) to (13), wherein the setting unit sets the mode information in the maximum encoding unit.
(17)
The intra prediction unit performs intra prediction of the second layer image in a coding unit of a predetermined size,
The setting unit sets the mode information in an encoding unit of the predetermined size,
The encoding device according to any one of (11) to (13), wherein the transmission unit transmits the mode information of the encoding unit of the predetermined size and size information indicating the predetermined size.
(18)
The intra prediction unit has an AVC (Advanced Video Coding) method for encoding the first layer image and a High Efficiency Video Coding (HEVC) method for the second layer image. In this case, the AVC intra prediction mode of the first layer image is converted into the HEVC intra prediction mode having the same angle as the corresponding angle, and the intra prediction mode of the second layer image is set. (11) The encoding device according to any one of (17).
(19)
The intra prediction unit has an AVC (Advanced Video Coding) method for encoding the first layer image and a High Efficiency Video Coding (HEVC) method for the second layer image. In this case, the Plain mode as the intra prediction mode of the first layer image is converted to the HEVC Planar mode to be the intra prediction mode of the second layer image. An encoding device according to claim 1.
(20)
The encoding device
An intra prediction step of performing intra prediction of the second layer image using the intra prediction mode of the first layer image of the image having a hierarchical structure as the intra prediction mode of the second layer image;
A setting step for setting mode information indicating that the intra prediction mode of the first layer image is used as the intra prediction mode of the second layer image;
A transmission step of transmitting the mode information set by the processing of the setting step.

30 encoding device, 34 transmission unit, 113 calculation unit, 122 skip prediction unit, 160 decoding device, 161 receiving unit, 242 skip prediction unit

Claims

A receiving unit that receives mode information indicating that an intra prediction mode of an image of a first layer of an image having a hierarchical structure is used as an intra prediction mode of an image of a second layer;
Based on the mode information received by the receiving unit, the intra prediction mode of the second layer image is used using the intra prediction mode of the first layer image as the intra prediction mode of the second layer image. A decoding device comprising: an intra prediction unit that performs prediction.
The intra prediction unit, based on the mode information, sets an intra prediction mode of a prediction block of the first layer image collocated with a prediction block of the second layer image of the second layer image. The decoding device according to claim 1, wherein intra prediction is performed as an intra prediction mode of a prediction block.
The intra-prediction unit sets the intra prediction mode of the prediction block of the first layer image to DC when there is no collocated prediction block of the first layer image and the prediction block of the first layer image. The decoding apparatus according to claim 2, wherein the decoding apparatus is in a mode.
The receiving unit receives the mode information of a coding unit;
The decoding device according to claim 1, wherein the intra prediction unit performs intra prediction of the second layer image in the coding unit based on the mode information of the coding unit.
The receiving unit receives the mode information in units of prediction blocks,
The decoding device according to claim 1, wherein the intra prediction unit performs intra prediction of the image of the second layer in the prediction block unit based on the mode information in the prediction block unit.
The receiving unit receives the mode information of a maximum coding unit;
The decoding apparatus according to claim 1, wherein the intra prediction unit performs intra prediction of the second layer image in the maximum coding unit based on the mode information of the maximum coding unit.
The receiving unit receives the mode information of an encoding unit of a predetermined size and size information indicating the predetermined size;
The intra prediction unit performs intra prediction of the second layer image in the encoding unit of the predetermined size based on the mode information of the encoding unit of the predetermined size and the size information. Decoding device.
In the intra prediction unit, the encoding method of the first layer image is an AVC (Advanced Video Coding) method, and the encoding method of the second layer image is a HEVC (High Efficiency Video Coding) method. In this case, based on the mode information, the AVC intra prediction mode of the first layer image is converted into an HEVC intra prediction mode having the same angle as the corresponding angle, and the second layer image is converted. The decoding device according to claim 1, wherein the intra prediction mode is selected.
The intra prediction unit has an AVC (Advanced Video Coding) method for encoding the first layer image and a High Efficiency Video Coding (HEVC) method for the second layer image. In this case, on the basis of the mode information, the Plain mode as the intra prediction mode of the first layer image is converted into the HEVC Planar mode, and the intra prediction mode of the second layer image is set. The decoding device according to 1.
The decryption device
Receiving the mode information indicating that the intra prediction mode of the first layer image of the image having the hierarchical structure is used as the intra prediction mode of the second layer image;
Based on the mode information received by the processing of the receiving step, the intra prediction mode of the image of the first layer is used as the intra prediction mode of the image of the second layer, and the image of the second layer An intra prediction step for performing intra prediction of.
An intra prediction unit that performs intra prediction of an image of the second hierarchy using an intra prediction mode of an image of the first hierarchy of an image having a hierarchical structure as an intra prediction mode of an image of the second hierarchy;
A setting unit that sets mode information indicating that the intra prediction mode of the first layer image is used as the intra prediction mode of the second layer image;
A transmission unit configured to transmit the mode information set by the setting unit.
The intra prediction unit uses an intra prediction mode of a prediction block of an image of the first layer collocated with a prediction block of the image of the second layer as an intra prediction mode of a prediction block of the image of the second layer. The encoding apparatus according to claim 11, wherein intra prediction is performed.
The intra-prediction unit sets the intra prediction mode of the prediction block of the first layer image to DC when there is no collocated prediction block of the first layer image and the prediction block of the first layer image. The encoding device according to claim 12, wherein the encoding device is a mode.
The intra prediction unit performs intra prediction of the second layer image in a coding unit,
The encoding device according to claim 11, wherein the setting unit sets the mode information in the encoding unit.
The intra prediction unit performs intra prediction of the second layer image in prediction block units,
The encoding device according to claim 11, wherein the setting unit sets the mode information in units of the prediction block.
The intra prediction unit performs intra prediction of the second layer image in a maximum coding unit;
The encoding device according to claim 11, wherein the setting unit sets the mode information in the maximum encoding unit.
The intra prediction unit performs intra prediction of the second layer image in a coding unit of a predetermined size,
The setting unit sets the mode information in an encoding unit of the predetermined size,
The encoding device according to claim 11, wherein the transmission unit transmits the mode information of the encoding unit of the predetermined size and size information indicating the predetermined size.
In the intra prediction unit, the encoding method of the first layer image is an AVC (Advanced Video Coding) method, and the encoding method of the second layer image is a HEVC (High Efficiency Video Coding) method. In this case, the AVC intra prediction mode of the first layer image is converted into an HEVC intra prediction mode having the same angle as the corresponding angle, and the intra prediction mode of the second layer image is set. Item 12. The encoding device according to Item 11.
In the intra prediction unit, the encoding method of the first layer image is an AVC (Advanced Video Coding) method, and the encoding method of the second layer image is a HEVC (High Efficiency Video Coding) method. 12. The encoding device according to claim 11, wherein the Plain mode as the intra prediction mode of the first layer image is converted into a Planar mode of the HEVC scheme to obtain the intra prediction mode of the second layer image.
The encoding device
An intra prediction step of performing intra prediction of the second layer image using the intra prediction mode of the first layer image of the image having a hierarchical structure as the intra prediction mode of the second layer image;
A setting step for setting mode information indicating that the intra prediction mode of the first layer image is used as the intra prediction mode of the second layer image;
A transmission step of transmitting the mode information set by the processing of the setting step.