JP6241500B2 - Image processing apparatus and method, and program - Google Patents

Description

  The present invention relates to an image processing apparatus and method, and a program, and more particularly to an image processing apparatus and method capable of suppressing a reduction in encoding efficiency by local control of filter processing at the time of encoding or decoding. , As well as programs.

  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 conforming to a system such as Moving Picture Experts Group) is becoming popular in both information distribution at broadcasting stations and information reception in general households.

  In particular, MPEG2 (ISO (International Organization for Standardization) / IEC (International Electrotechnical Commission) 13818-2) is defined as a general-purpose image coding system, and includes both interlaced scanning images and progressive scanning images, as well as standard resolution images and This standard covers high-definition images and is currently widely used in a wide range of professional and consumer applications. By using the MPEG2 compression 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. (Bit rate) can be assigned to achieve a high compression rate and good image quality.

  MPEG2 was mainly intended for high-quality encoding suitable for broadcasting, but 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 portable 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 image coding system, the standard was approved as an international standard as ISO / IEC 14496-2 in December 1998.

  Furthermore, in recent years, the standardization of a standard called H.26L (ITU-T (ITU Telecommunication Standardization Sector) Q6 / 16 VCEG (Video Coding Experts Group)) has been advanced for the purpose of image coding for an initial video conference. H.26L is known to achieve higher encoding efficiency than a conventional encoding method such as MPEG2 or MPEG4, although a large amount of calculation is required for encoding and decoding. Also, as part of MPEG4 activities, standardization to achieve higher coding efficiency based on this H.26L and incorporating functions not supported by H.26L has been carried out as Joint Model of Enhanced-Compression Video Coding. It has been broken. As a standardization schedule, in March 2003, it became an international standard under the names of H.264 and MPEG4 Part 10 (AVC (Advanced Video Coding)).

  In addition, there is an adaptive loop filter (ALF (Adaptive Loop Filter)) as a next-generation video coding technique that has been recently examined (see, for example, Non-Patent Document 1). With this adaptive filter, optimal filter processing is performed for each frame, and block distortion that cannot be removed by the deblocking filter and distortion due to quantization can be reduced.

  However, since the image generally has various features locally, the optimum filter coefficient is different locally. In the method described in Non-Patent Document 1, since the same filter coefficient is applied to all the pixels in one frame, the image quality is improved in the entire frame, but there is a possibility that it is locally deteriorated.

  In view of this, there has been considered a method in which the filtering process is not performed on a locally deteriorated region (for example, see Non-Patent Document 2 and Non-Patent Document 3). In the case of this method, the image encoding device associates a plurality of control blocks arranged without gaps so as to be spread over an image area, and controls whether or not to perform filter processing on the image for each control block. The image encoding apparatus sets flag information for each block, and performs adaptive filter processing according to the flag information. Similarly, the image decoding apparatus performs adaptive filter processing based on the flag information.

  In this case, the size of the control block, the flag information of each control block, the filter coefficient information of the adaptive filter process, the number of filter TAPs, etc. so that the adaptive filter process similar to that at the time of encoding can be executed at the time of decoding Control information (ALF control information) needs to be included in the encoded data.

  Since this ALF control information often changes for each picture, it is included in a picture parameter set (PPS (Picture Parameter Set)) or a sequence parameter set (SPS (Sequence Parameter Set)) in the conventional idea. However, if you try to include ALF control information in these PPS and SPS, information that is not directly related to ALF, such as pic_order_present_flag, num_ref_idx_l0_active_minus1, profile_idc, and level_idc, is included in the image compression information. There is a possibility that the coding efficiency is deteriorated by the overhead.

  In addition, even if an independent NAL (Network Abstraction Layer) unit is created and the above unnecessary information is removed, start code, nal_ref_idc, and nal_unit_type are required, and these overheads may deteriorate coding efficiency. .

  In order to avoid such a problem, it has been proposed to include these ALF control information in the slice header (see, for example, Non-Patent Document 4). There has also been proposed a method of placing pointer information indicating the location of ALF control information without placing ALF control information in the slice header (see Non-Patent Document 5, for example).

Yi-Jen Chiu and L. Xu, “Adaptive (Wiener) Filter for Video Compression,” ITU-T SG16 Contribution, C437, Geneva, April 2008. Takeshi. Chujoh, et al., “Block-based Adaptive Loop Filter” ITU-T SG16 Q6 VCEG Contribution, AI18, Germany, July, 2008 T. Chujoh, N. Wada and G. Yasuda, “Quadtree-based Adaptive Loop Filter,” ITU-T SG16 Q6 VCEG Contribution, VCEG-AK22 (r1), Japan, April, 2009 Takeshi. Chujoh, et al., "Improvement of Block-based Adaptive Loop Filter" ITU-T SG16 Q6 VCEG Contribution, AJ13, San Diego, October, 2008 Yu-Wen Huang, et all., “Adaptive Quadtree-based Multi-reference Loop Filter”, ITU-T SG16 Q6 VCEG Contribution, AK24, Yokohama Japan, April, 2009

  By the way, there is a method (multi-slice) in which one frame is divided into a plurality of slices and image coding processing and decoding processing are performed for each slice. Dividing a frame into a plurality of slice areas is an effective method for increasing error tolerance during transfer of image compression information.

  However, Non-Patent Document 2 to Non-Patent Document 5 only describe that blocks are set for one entire frame, and flag information of all blocks is generated and transmitted. In this case, the processing of flag information was not described, and it was unclear how to generate and use flag information.

  Therefore, in the case of the method described in the non-patent document, the image encoding device generates flag information of all blocks in the frame for each slice, and the encoding efficiency is improved by unnecessary flag information or the like. There was a risk of worsening.

  In addition, as described above, Non-Patent Document 4 proposes to include ALF control information in a slice header, but in the case of multi-slice, the ALF control information generated for each slice is encoded data. If included in each of the slice headers, there may be a portion where the contents overlap between the plurality of ALF control information. That is, there is a fear that the encoding efficiency is unnecessarily reduced.

  The same applies when a pointer is placed on a slice header as described in Non-Patent Document 5, and when a pointer is placed on a plurality of slice headers, duplicated information is included in the encoded data, making encoding efficiency unnecessary. There was a risk of reduction.

  The present invention has been proposed in view of such a situation, and an object thereof is to suppress a reduction in encoding efficiency due to local control of filter processing at the time of encoding or decoding.

One aspect of the present invention encodes an image, and includes, as header information of a specific slice of the plurality of slices of the image, filter control information for controlling filter processing in units of slices corresponding to the plurality of slices It is an image processing apparatus provided with the encoding part which produces | generates a bit stream.

The encoding unit may include the filter control information in header information of the slice transmitted at the beginning of a frame.

The encoding unit may include the filter control information in header information of the slice located at the head of the frame.

The image processing apparatus may further include a filter unit that performs the filtering process on the image according to the filter control information.

Further comprising a deblocking filter processing unit that performs deblocking filtering process on the image, the filter unit, the filter processing on the deblocking the image filter processing is performed by the deblocking filter processing unit Can be configured to do.

One aspect of the present invention also encodes an image, and filter control information for controlling filter processing in units of slices corresponding to the plurality of slices as header information of a specific slice among the plurality of slices of the image An image processing method for generating a bitstream including

The filter control information may be included in header information of the slice transmitted at the beginning of a frame.

The filter control information can be included in the header information of the slice located at the head of the frame.

The filter processing may be performed on the image according to the filter control information.

Wherein performs deblock filter processing for the image, the deblocking filter processing Ru can be to perform the filtering process on the image performed.

In one aspect of the present invention, the computer further encodes an image, and controls filtering processing in units of slices corresponding to the plurality of slices as header information of a specific slice of the plurality of slices of the image. This is a program that functions as an encoding unit that generates a bitstream including filter control information.

In one aspect of the present invention, an image is encoded as header information for a particular slice of the plurality of slices of the image, corresponding to a plurality of slices, the filter control information for controlling the filtering process in units of slices A bitstream containing it is generated.

  According to the present invention, an image can be encoded or decoded. In particular, it is possible to further suppress a reduction in encoding efficiency due to local control of filter processing during encoding or decoding. For example, even when each frame of an image is encoded or decoded by dividing it into a plurality, it is possible to further suppress a reduction in encoding efficiency.

It is a block diagram which shows the main structural examples of the image coding apparatus to which this invention is applied. It is a figure explaining variable block size motion prediction and compensation processing. It is a block diagram which shows the main structural examples of a control information generation part. It is a figure explaining an ALF block and a filter block flag. It is a figure explaining the example of multi-slice. It is a figure explaining the process of slice 0. FIG. It is a figure explaining the process of slice 1. FIG. It is a figure explaining the process of the slice 1 to which this invention is applied. It is a block diagram which shows the main structural examples of an adaptive filter process part. It is a block diagram which shows the main structural examples of a lossless encoding part. It is a figure explaining a mode that control information is included in the header of the slice transmitted first. It is a figure which shows the example of the syntax of a slice header. It is a flowchart explaining the example of the flow of an encoding process. It is a flowchart explaining the example of the flow of a control information generation process. It is a flowchart explaining the example of the flow of a block information generation process. It is a flowchart explaining the example of the flow of an adaptive filter process. It is a flowchart explaining the example of the flow of a lossless encoding process. It is a block diagram which shows the main structural examples of the image decoding apparatus to which this invention is applied. It is a block diagram which shows the main structural examples of a lossless decoding part. It is a flowchart explaining the example of the flow of a decoding process. It is a flowchart explaining the example of the flow of a lossless decoding process. It is a figure explaining a mode that control information is included in the header of the head slice. It is a flowchart explaining the other example of the flow of a lossless encoding process. It is a block diagram which shows the other structural example of a lossless decoding part. It is a flowchart explaining the other example of the flow of a lossless decoding process. It is a figure explaining a mode that control information is included in the header of arbitrary slices. It is a flowchart explaining the further another example of the flow of a lossless encoding process. It is a flowchart explaining the further another example of the flow of a lossless decoding process. It is a figure explaining a mode that a pointer is included in the header of a slice. It is a flowchart explaining the further another example of the flow of a lossless encoding process. It is a flowchart explaining the further another example of the flow of a lossless decoding process. It is a figure explaining a mode that control information is put together in the header of a slice for every group. It is a flowchart explaining the further another example of the flow of a lossless encoding process. It is a block diagram which shows the other structural example of a lossless encoding part. It is a flowchart explaining the further another example of the flow of a lossless encoding process. It is a block diagram which shows the other structural example of a lossless decoding part. It is a flowchart explaining the further another example of the flow of a lossless decoding process. It is a block diagram which shows the other structural example of a lossless encoding part. It is a flowchart explaining the further another example of the flow of a lossless encoding process. It is a block diagram which shows the other structural example of a lossless decoding part. It is a flowchart explaining the further another example of the flow of a lossless decoding process. It is a figure explaining the other example of an ALF block and a filter block flag. It is a figure explaining the other example of an ALF block and a filter block flag. It is a figure explaining the mode of processing in the case of multi-slice. It is a block diagram which shows the main structural examples of the personal computer to which this invention is applied. It is a block diagram which shows the main structural examples of the television receiver to which this invention is applied. It is a block diagram which shows the main structural examples of the mobile telephone to which this invention is applied. It is a block diagram which shows the main structural examples of the hard disk recorder to which this invention is applied. It is a block diagram which shows the main structural examples of the camera to which this invention is applied. It is a figure which shows the example of a macroblock.

Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. First Embodiment (Image Encoding Device)
2. Second embodiment (image decoding apparatus)
3. Third embodiment (example in which control information is included in header of first slice)
4). Fourth embodiment (an example in which control information is included in the header of an arbitrary slice)
5. Fifth embodiment (example using a pointer)
6). Sixth embodiment (example of collecting control information into a plurality of groups)
7). Seventh embodiment (example of controlling the number of groups)
8). Eighth embodiment (example in which elements are grouped independently)
9. Ninth embodiment (QALF)
10. Tenth embodiment (personal computer)
11. Eleventh embodiment (television receiver)
12 Twelfth embodiment (mobile phone)
13. 13th Embodiment (Hard Disk Recorder)
14 Fourteenth embodiment (camera)

<1. First Embodiment>
[Device Configuration]
FIG. 1 shows a configuration of an embodiment of an image encoding apparatus as an image processing apparatus to which the present invention is applied.

  An image encoding device 100 shown in FIG. It is an encoding device that compresses and encodes an image using an H.264 and MPEG4 Part 10 (Advanced Video Coding) (hereinafter referred to as H.264 / AVC) method, and further employs an adaptive loop filter.

  In the example of FIG. 1, the image encoding device 100 includes an A / D (Analog / Digital) conversion unit 101, a screen rearrangement buffer 102, a calculation unit 103, an orthogonal conversion unit 104, a quantization unit 105, and a lossless encoding unit 106. And a storage buffer 107. In addition, the image coding apparatus 100 includes an inverse quantization unit 108, an inverse orthogonal transform unit 109, a calculation unit 110, and a deblock filter 111. Furthermore, the image coding apparatus 100 includes a control information generation unit 112, an adaptive filter processing unit 113, and a frame memory 114. In addition, the image encoding device 100 includes an intra prediction unit 115, a motion compensation unit 116, a motion prediction unit 117, and a predicted image selection unit 118. Furthermore, the image encoding device 100 includes a rate control unit 119.

  The A / D conversion unit 101 performs A / D conversion on the input image data, and outputs to the screen rearrangement buffer 102 for storage. The screen rearrangement buffer 102 rearranges the stored frame images in the display order in the order of frames for encoding in accordance with the GOP (Group of Picture) structure.

  The calculation unit 103 subtracts the prediction image from the intra prediction unit 115 selected by the prediction image selection unit 118 or the prediction image from the motion compensation unit 116 from the image read from the screen rearrangement buffer 102, and the difference between them. Information is output to the orthogonal transform unit 104. The orthogonal transform unit 104 performs orthogonal transform such as discrete cosine transform and Karhunen-Loeve transform on the difference information from the operation unit 103, and outputs the transform coefficient. The quantization unit 105 quantizes the transform coefficient output from the orthogonal transform unit 104.

  The quantized transform coefficient that is output from the quantization unit 105 is input to the lossless encoding unit 106. The lossless encoding unit 106 performs lossless encoding such as variable length encoding and arithmetic encoding on the quantized transform coefficient.

  The lossless encoding unit 106 acquires information indicating intra prediction from the intra prediction unit 115 and acquires information indicating inter prediction mode from the motion prediction unit 117. Note that information indicating intra prediction is hereinafter also referred to as intra prediction mode information. In addition, information indicating an information mode indicating inter prediction is hereinafter also referred to as inter prediction mode information.

  The lossless encoding unit 106 further acquires control information of adaptive filter processing performed in the adaptive filter processing unit 113 from the control information generation unit 112.

  The lossless encoding unit 106 encodes the quantized transform coefficient, and also transmits control information for adaptive filter processing, information indicating intra prediction, information indicating inter prediction mode, and quantization parameters, etc. A part of header information (multiplexed) The lossless encoding unit 106 supplies the encoded data obtained by encoding to the accumulation buffer 107 for accumulation.

  For example, the lossless encoding unit 106 performs lossless encoding processing such as variable length encoding or arithmetic encoding. Examples of variable length coding include H.264. CAVLC (Context-Adaptive Variable Length Coding) defined in H.264 / AVC format. Examples of arithmetic coding include CABAC (Context-Adaptive Binary Arithmetic Coding).

  The accumulation buffer 107 temporarily holds the encoded data supplied from the lossless encoding unit 106, and at a predetermined timing, the H.264 buffer stores the encoded data. As an encoded image encoded by the H.264 / AVC format, for example, it is output to a recording device or a transmission path (not shown) in the subsequent stage.

  Further, the transform coefficient quantized by the quantization unit 105 is also input to the inverse quantization unit 108. The inverse quantization unit 108 inversely quantizes the quantized transform coefficient by a method corresponding to the quantization by the quantization unit 105, and supplies the obtained transform coefficient to the inverse orthogonal transform unit 109.

  The inverse orthogonal transform unit 109 performs inverse orthogonal transform on the supplied transform coefficient by a method corresponding to the orthogonal transform process by the orthogonal transform unit 104. The output subjected to inverse orthogonal transform is supplied to the calculation unit 110. The calculation unit 110 adds the predicted image supplied from the predicted image selection unit 118 to the inverse orthogonal transform result supplied from the inverse orthogonal transform unit 109, that is, the restored difference information, and locally decoded image (Decoded image) is obtained. The addition result is supplied to the deblocking filter 111.

  The deblocking filter 111 removes block distortion of the decoded image. The deblocking filter 111 supplies the distortion removal result to the control information generation unit 112 and the adaptive filter processing unit 113.

  The control information generation unit 112 acquires the decoded image supplied from the deblocking filter 111 and the current input image read from the screen rearrangement buffer 102, and uses the adaptive filter processing unit 113 to perform an adaptive filter Control information is generated. Although details will be described later, the control information includes a filter coefficient, a block size, a filter block flag, and the like.

  The control information generation unit 112 supplies the generated control information to the adaptive filter processing unit 113. The control information generation unit 112 also supplies the generated control information to the lossless encoding unit 106. As described above, the control information is included (multiplexed) in the encoded data by the lossless encoding unit 106. That is, the control information is sent to the image decoding device together with the encoded data.

  The adaptive filter processing unit 113 performs a filter process on the decoded image supplied from the deblocking filter 111 using the filter coefficient, block size designation, filter block flag, and the like of the control information supplied from the control information generating unit 112. . As this filter, for example, a Wiener Filter is used. Of course, filters other than the Wiener filter may be used. The adaptive filter processing unit 113 supplies the filter processing result to the frame memory 114 and accumulates it as a reference image.

  The frame memory 114 outputs the stored reference image to the motion compensation unit 116 and the motion prediction unit 117 at a predetermined timing.

  In this image encoding device 100, for example, an I picture, a B picture, and a P picture from the screen rearrangement buffer 102 are supplied to the intra prediction unit 115 as images to be intra predicted (also referred to as intra processing). In addition, the B picture and the P picture read from the screen rearrangement buffer 102 are supplied to the motion prediction unit 117 as images to be inter predicted (also referred to as inter processing).

  The intra prediction unit 115 performs intra prediction processing for all candidate intra prediction modes based on the intra-predicted image read from the screen rearrangement buffer 102 and the reference image supplied from the frame memory 114, and performs prediction. Generate an image.

  In the intra prediction unit 115, information on the intra prediction mode applied to the block / macro block is transmitted to the lossless encoding unit 106 and is a part of header information in the encoded data. In the H.264 image information encoding method, an intra 4 × 4 prediction mode, an intra 8 × 8 prediction mode, and an intra 16 × 16 prediction mode are defined for the luminance signal, and regarding the color difference signal, For each macroblock, it is possible to define a prediction mode independent of the luminance signal. For the intra 4 × 4 prediction mode, one intra prediction mode is defined for each 4 × 4 luminance block. For the intra 8 × 8 prediction mode, one intra prediction mode is defined for each 8 × 8 luminance block. For the intra 16 × 16 prediction mode and the color difference signal, one prediction mode is defined for each macroblock.

  The intra prediction unit 115 calculates a cost function value for the intra prediction mode in which the predicted image is generated, and selects an intra prediction mode in which the calculated cost function value gives the minimum value as the optimal intra prediction mode. The intra prediction unit 115 supplies the predicted image generated in the optimal intra prediction mode to the predicted image selection unit 118.

  The motion prediction unit 117 uses the image information (input image) supplied from the screen rearrangement buffer 102 and the image information (decoded image) serving as a reference frame supplied from the frame memory 114 for the image to be inter-coded. Obtain the motion vector. The motion prediction unit 117 supplies motion vector information indicating the calculated motion vector to the lossless encoding unit 106. This motion vector information is included (multiplexed) in the encoded data by the lossless encoding unit 106. That is, the motion vector information is sent to the image decoding device together with the encoded data.

  The motion prediction unit 117 also supplies the motion vector information to the motion compensation unit 116.

  The motion compensation unit 116 performs motion compensation processing according to the motion vector information supplied from the motion prediction unit 117, and generates inter prediction image information. The motion compensation unit 116 supplies the generated predicted image information to the predicted image selection unit 118.

  The predicted image selection unit 118 supplies the output of the intra prediction unit 115 to the calculation unit 103 in the case of an image to be subjected to intra coding, and outputs the output of the motion compensation unit 116 to the calculation unit 103 in the case of an image to be subjected to inter coding. Supply.

  Based on the compressed image stored in the storage buffer 107, the rate control unit 119 controls the quantization operation rate of the quantization unit 105 so that overflow or underflow does not occur.

  In MPEG (Moving Picture Experts Group) 2, the unit of motion prediction / compensation processing is a motion compensation block, and each motion compensation block can have independent motion vector information. The size of the motion compensation block is 16 × 16 pixels in the frame motion compensation mode, and 16 × 8 pixels in each of the first field and the second field in the field motion compensation mode.

  On the other hand, in AVC (Advanced Video Coding), as shown in the upper side of FIG. 2, one macro block composed of 16 × 16 pixels is converted into 16 × 16, 16 × 8, 8 × 16, or 8 × 8. It is possible to divide each of the partitions into independent motion vector information. Further, as shown in the lower side of FIG. 2, the 8 × 8 partition is divided into 8 × 8, 8 × 4, 4 × 8, and 4 × 4 subpartitions, and independent motion vector information is obtained. It is possible to have. Motion prediction / compensation processing is performed in units of this motion compensation block.

  FIG. 3 is a block diagram illustrating a main configuration example of the control information generation unit 112.

  As described above, the control information generation unit 112 generates control information used in the adaptive filter (ALF (Adaptive Loop Filter)) that is a loop filter performed in the adaptive filter processing unit 113. For example, the control information generation unit 112 generates a filter coefficient, an ALF block size, and a filter block flag as the control information.

  The control information generation unit 112 includes a filter coefficient calculation unit 131 and a block information generation unit 132.

  The filter coefficient calculation unit 131 acquires the decoded image supplied from the deblocking filter 111 and the current input image read from the screen rearrangement buffer 102, and calculates the ALF filter coefficient for each frame from them. .

  The block information generation unit 132 generates block information such as an ALF block size and a filter block flag. For example, the block information generation unit 132 determines the ALF block size based on the decoded image supplied from the deblocking filter 111 and the filter coefficient calculated by the filter coefficient calculation unit 131. For example, the block information generation unit 132 generates a filter block flag for each ALF block in the processing target slice based on the information.

  Here, the ALF block and the filter block flag of the block information will be described. FIG. 4 is a diagram for explaining the ALF block and the filter block flag.

  As described above, in the adaptive filter, a filter coefficient is set for each frame. That is, optimal filter processing is performed on a frame basis. However, in general, the frame image is not uniform as a whole and has various features locally. Therefore, the optimum filter coefficient is locally different. Therefore, as described above, in the filter processing using the filter coefficient determined for each frame, the image quality is improved in the entire frame, but there is a possibility that it may be deteriorated locally.

  In view of this, a BALF (Block based Adaptive Loop Filter) has been considered in which filter processing is not performed in a region where image quality locally deteriorates.

  A frame 151 in FIG. 4A shows a decoded image after the deblocking filter process. As shown in FIG. 4B, the block information generation unit 132 adds a plurality of ALF blocks 152, each of which is a control unit of adaptive filter processing performed locally, to the entire area of the frame 151. Arrange them without gaps so that they are spread. The area where the ALF block 152 is arranged may not be the same as the area of the frame 151, but includes at least the entire area of the frame. As a result, the area of the frame 151 is divided by the area (a plurality of control areas) of each ALF block 152.

  The block information generation unit 132 determines the horizontal size (double arrow 153) and the vertical size (double arrow 154) of the ALF block 152. For the ALF block size, for example, one of 8 × 8, 16 × 16, 24 × 24, 32 × 32, 48 × 48, 64 × 64, 96 × 96, or 128 × 128 is designated for each slice. can do. Information specifying the size of the ALF block is referred to as a block size index.

  If the block size is determined, the frame size is fixed, so the number of ALF blocks per frame is also determined.

  As illustrated in FIG. 4C, the block information generation unit 132 sets a filter block flag 155 that controls whether to perform filter processing for each ALF block 152. For example, a filter block flag 155 having a value “1” is generated for a region where the image quality is improved by the adaptive filter, and a filter block flag 155 having a value “0” is generated for a region where the image quality is deteriorated by the adaptive filter. Generated. In the filter block flag 155, the value “1” is a value indicating that the filtering process is performed, and the value “0” is a value indicating that the filtering process is not performed.

  The adaptive filter processing unit 113 controls adaptive filter processing based on the value of the filter block flag 155. For example, the adaptive filter processing unit 113 performs the filtering process only on the area of the ALF block 152 in which the value of the filter block flag 155 is “1”, and the area of the ALF block 152 in which the value of the filter block flag 155 is “0”. Do not filter.

  The block size index and the filter block flag described above are included in the slice header of the encoded data, and are sent from the image encoding device 100 to the image decoding device. One or more filter block flags corresponding to the number of ALF blocks are included in the slice header in the raster scan order, for example.

  Therefore, as the ALF block size is smaller, finer filter control is possible, and a more appropriate ALF filter is possible. However, if the size of the ALF block is reduced, the bit amount of the filter block flag increases. That is, the encoding efficiency of encoded data decreases as the size of the ALF block decreases. As described above, the performance of the adaptive filter and the encoding efficiency of the encoded data are in a trade-off relationship.

  The number of ALF blocks is calculated as in the following equation (1).

In Formula (1), N _ALFBLOCK indicates the number of ALF blocks. N _MBw represents the number of macroblocks in the horizontal direction of the picture, and N _MBh represents the number of _macrobooks in the vertical direction of the picture. Further, N _SIZE indicates the size of one side of the ALF block. Floor [x] is a function that rounds off the decimal point of x to an integer.

  By the way, in H.264 / AVC, one frame can be divided into a plurality of slices, and encoded data can be output for each slice. FIG. 5 is a diagram illustrating an example of multi-slice. In the example of FIG. 5, the frame 151 is divided into three slices, slice 0, slice 1, and slice 2.

  Dividing a frame into a plurality of slice areas is an effective method for increasing error tolerance during transfer of image compression information.

  Non-patent document 2 describing BALF does not disclose this multi-slice. That is, only the setting of the ALF block for the entire frame is described. As described above, the ALF block is set for the entire frame. That is, an ALF block for the entire frame is set for each slice, and there is a possibility that an unnecessary ALF block outside the slice area is set.

  For example, in the example of the slice configuration shown in FIG. 5, when processing slice 0 as shown in FIG. 6A, as shown in FIG. 6B, for the region of slice 0 shown in frame 161, frame 151 An ALF block 152 is set for the whole.

  Similarly, for example, when processing slice 1 as illustrated in FIG. 7A in the example of the slice configuration illustrated in FIG. 5, as illustrated in FIG. 7B, for the region of slice 1 illustrated in the frame 162, as illustrated in FIG. An ALF block 152 for the entire frame 151 is set.

  6B and 7B, the ALF block 152 indicated by hatching is a block outside the area of slice 0 or slice 1, and is an unnecessary block for processing of the area of slice 0 or slice 1.

  Setting such an unnecessary block and the flag of the block is meaningless processing. Therefore, in order not to increase the processing unnecessarily, the block information generation unit 132 of the control information generation unit 112 in FIG. 3 generates only the ALF block and the filter block flag including the region of the slice to be processed.

  For example, when the slice 1 is processed as illustrated in FIG. 8A in the example of the slice configuration illustrated in FIG. 5, the block information generation unit 132 performs the area of the slice 1 illustrated in the frame 162 as illustrated in FIG. 8B. On the other hand, only the ALF block 152 including the area is set, and the filter block flag is generated only for the ALF block 152.

  Returning to FIG. 3, the block information generating unit 132 includes a processing target slice region specifying unit 141, an ALF block setting unit 142, a processing target ALF block region specifying unit 143, a determining unit 144, and a filter block flag generating unit 145.

  The processing target slice area specifying unit 141 specifies the position in the entire frame of the area of the processing target slice supplied as a decoded image.

  The ALF block setting unit 142 determines the ALF block size and sets the ALF block 152 of the entire frame. This also specifies the number of ALF blocks in the entire frame.

  The processing target ALF block area specifying unit 143 selects one ALF block to be processed one by one from the ALF blocks 152 set by the ALF block setting unit 142, and specifies the position of the area of the selected processing target ALF block. .

  The determination unit 144 determines whether the area of the processing target ALF block includes the area of the processing target slice. The filter block flag generation unit 145 generates a filter block flag of the ALF block determined by the determination unit 144 as “including the region of the processing target slice”. The filter block flag generation unit 145 performs adaptive filter processing on the region of the processing target ALF block using the filter coefficient calculated by the filter coefficient calculation unit 131, and the image quality of the filter processing result is improved from before the processing. The value of the filter block flag is determined depending on whether or not it exists.

  The filter block flag generation unit 145 outputs control information such as a filter block flag and an ALF block size.

  FIG. 9 is a block diagram illustrating a main configuration example of the adaptive filter processing unit 113 in FIG.

  The adaptive filter processing unit 113 performs filter processing on the decoded image supplied from the deblocking filter 111 using the control information supplied from the control information generating unit 112.

  As illustrated in FIG. 9, the adaptive filter processing unit 113 includes a control unit 171, an adaptive filter 172, and a selection unit 173.

  The control unit 171 controls the adaptive filter 172 and the selection unit 173. For example, the control unit 171 acquires control information from the control information generation unit 112. In addition, the control unit 171 supplies the filter coefficient included in the acquired control information to the adaptive filter 172 and sets it. Further, the control unit 171 specifies the position of the region of the ALF block to be processed based on the ALF block size included in the control information. Further, the control unit 171 controls the adaptive filter 172 based on the value of the filter block flag included in the control information, performs filter processing on the area of each ALF block as necessary, and controls the operation of the selection unit 173. To do.

  The adaptive filter 172 filters the region specified as the processing target ALF block by the control unit 171 of the decoded image supplied from the deblocking filter 111 using the filter coefficient set by the control unit 171. The adaptive filter 172 supplies the filter processing result to the selection unit 173.

  The selection unit 173 is controlled by the control unit 171, and the decoded image (decoded image not subjected to adaptive filter processing) supplied from the deblocking filter 111 and the decoded image (decoded image subjected to adaptive filter processing) supplied from the adaptive filter 172. Image) is supplied to the frame memory 114 and stored as a reference image.

  That is, the adaptive filter processing unit 113 indicates that the decoded image supplied from the deblocking filter 111 is subjected to the filter processing by the filter block flag (region determined to improve the image quality by the filter processing). Only filter.

  FIG. 10 is a block diagram illustrating a main configuration example of the lossless encoding unit 106 of FIG.

  As described above, the lossless encoding unit 106 performs lossless encoding on the quantized coefficient data supplied from the quantization unit 105 to generate encoded data, and the control information supplied from the control information generation unit 112. Are embedded (described) in the slice header of the encoded data. At this time, the lossless encoding unit 106 collects control information for each slice in the picture (frame) and embeds the control information for one picture (one frame) in one slice header. By doing in this way, the lossless encoding part 106 can delete the part (redundant part) which overlaps between the control information of each slice, and can embed it in a slice header. Thereby, the lossless encoding part 106 can improve the encoding efficiency of encoded data rather than the case where the control information of each slice is each embedded in encoded data.

  As shown in FIG. 10, the lossless encoding unit 106 includes an encoding unit 181, an encoded data holding unit 182, a control information holding unit 183, and a control information adding unit 184.

  The encoding unit 181 performs lossless encoding on the image data (quantized coefficient data) of each slice, and generates encoded data. The encoded data of each slice is held in the encoded data holding unit 182. The encoded data holding unit 182 can hold encoded data for at least one picture.

  The control information holding unit 183 acquires and holds the control information for each slice generated by the control information generating unit 112. The control information holding unit 183 can hold control information for at least one picture. The control information adding unit 184 embeds the control information held in the control information holding unit 183 in the header information of the slice output first in the picture of the encoded data held in the encoded data holding unit 182. To the storage buffer 107.

  At this time, the control information adding unit 184 collects the control information of the processing target pictures held in the control information holding unit 183, deletes the redundant part, generates control information for one picture, and encodes it Embed in the slice header of the data.

  For example, as illustrated in FIG. 11, the frame 151 includes slice 0, slice 1, and slice 2, and the control information generation unit 112 generates control information 191-1 for slice 0. Control information 191-2 is generated, and control information 191-3 is generated for slice 2.

  Also, it is assumed that the encoded data 194 is output in the order of slice 1, slice 0, and slice 2. That is, the encoded data 194 is in the order of the slice 1 header 192-1, the slice 1 data 193-1, the slice 0 header 192-2, the slice 0 data 193-2, the slice 2 header 192-3, and the slice 2 data 193-3. Suppose that it is output.

  At this time, the control information adding unit 184 embeds all the control information 191-1 to control information 191-3 of the frame 151 in the slice 1 header 192-1 that is the header (slice header) of slice 1 that is output first. . At this time, the control information adding unit 184 collects the control information 191-1 to the control information 191-3, deletes the redundant portion, and controls information 191 (for one picture) corresponding to the entire frame 151 (not shown). And embeds the control information 191 in the slice 1 header 192-1.

  The control information adding unit 184 embeds the control information in the slice header according to the syntax as shown in FIGS. 12A and 12B, for example. FIG. 12A shows an example of the syntax of the slice header, and FIG. 12B shows an example of the syntax for the control information part. As illustrated in FIG. 12B, the control information adding unit 184 embeds the filter block flags of all the control blocks in the frame 151 in one slice header.

[Process flow]
Next, the flow of processing using each unit configured as described above will be described. Initially, the example of the flow of the encoding process performed by the image coding apparatus 100 is demonstrated with reference to the flowchart of FIG.

  In step S101, the A / D conversion unit 101 performs A / D conversion on the input image. In step S102, the screen rearrangement buffer 102 stores the A / D converted image, and rearranges the picture from the display order to the encoding order.

  In step S103, the calculation unit 103 calculates the difference between the image rearranged by the process in step S102 and the predicted image. The predicted image is supplied from the motion compensation unit 116 in the case of inter prediction, and from the intra prediction unit 115 in the case of intra prediction, to the calculation unit 103 via the predicted image selection unit 118, respectively.

  The difference data has a smaller data amount than the original image data. Therefore, the data amount can be compressed as compared with the case where the image is encoded as it is.

  In step S104, the orthogonal transform unit 104 performs orthogonal transform on the difference information generated by the process in step S103. Specifically, orthogonal transformation such as discrete cosine transformation and Karhunen-Loeve transformation is performed, and transformation coefficients are output. In step S105, the quantization unit 105 quantizes the transform coefficient. At the time of this quantization, the rate is controlled as described in the process of step S119 described later.

  The difference information quantized as described above is locally decoded as follows. That is, in step S106, the inverse quantization unit 108 inversely quantizes the transform coefficient quantized by the quantization unit 105 with characteristics corresponding to the characteristics of the quantization unit 105. In step S <b> 107, the inverse orthogonal transform unit 109 performs inverse orthogonal transform on the transform coefficient inversely quantized by the inverse quantization unit 108 with characteristics corresponding to the characteristics of the orthogonal transform unit 104.

  In step S108, the calculation unit 110 adds the predicted image input via the predicted image selection unit 118 to the locally decoded difference information, and outputs the locally decoded image (for input to the calculation unit 103). Corresponding image). In step S <b> 109, the deblocking filter 111 filters the image output from the calculation unit 110. Thereby, block distortion is removed.

  When the above processing is performed for one slice, in step S110, the control information generation unit 112 generates control information used for adaptive filter processing. Details of the control information generation process will be described later.

  When control information such as a filter coefficient, an ALF block size, and a filter block flag is generated by the process in step S110, the adaptive filter processing unit 113 uses the control information in step S111 to perform the process in step S109. An adaptive filter process is performed on the decoded image subjected to the deblocking filter process. Details of the adaptive filter processing will be described later.

  In step S112, the frame memory 114 stores the image subjected to the adaptive filter processing in step S111.

  In step S113, the intra prediction unit 115 performs an intra prediction process in the intra prediction mode. In step S114, the motion prediction unit 117 and the motion compensation unit 116 perform inter motion prediction / compensation processing in the inter prediction mode.

  In step S115, the predicted image selection unit 118 selects either the predicted image generated by the intra prediction process or the predicted image generated by the inter motion prediction / compensation process, according to the prediction mode of the processing target frame. Select one. The predicted image selection unit 118 supplies the selected predicted image to the calculation unit 103 and the calculation unit 110. As described above, this predicted image is used for the calculations in step S103 and step S108.

  In step S 116, the lossless encoding unit 106 performs a lossless encoding process for encoding the quantized transform coefficient output from the quantization unit 105. That is, the difference image is subjected to lossless encoding such as variable length encoding and arithmetic encoding, and is compressed. At this time, the lossless encoding unit 106 includes metadata such as the control information generated in step S110, the intra prediction mode information in the intra prediction process in step S113, and the inter prediction mode in the inter motion prediction / compensation process in step S114. Is embedded (described) in the slice header. This metadata is read and used at the time of image decoding. Details of the lossless encoding process will be described later.

  In step S117, the accumulation buffer 107 accumulates encoded data. The encoded data stored in the storage buffer 107 is appropriately read out and transmitted to the decoding side via the transmission path.

  In step S118, the rate control unit 119 controls the rate of the quantization operation of the quantization unit 105 based on the encoded data stored in the storage buffer 107 so that overflow or underflow does not occur.

  Next, an example of the flow of control information generation processing executed by the control information generation unit 112 in step S110 of FIG. 13 will be described with reference to the flowchart of FIG.

  When the control information generation process is started, the filter coefficient calculation unit 131 of the control information generation unit 112 receives the input image supplied from the screen rearrangement buffer 102 and the deblock supplied from the deblock filter 111 in step S131. A filter coefficient is calculated using the decoded image after filtering. For example, the filter coefficient calculation unit 131 determines the filter coefficient value so that the residual between the input image and the decoded image is minimized.

  When the filter coefficient is calculated, the block information generation unit 132 generates block information including an ALF block size and a filter block flag in step S132. Details of the block information generation processing will be described later. When the block information is generated, the process returns to step S110 in FIG. 13, and the processes after step S111 are executed.

  Note that the filter coefficient calculation performed in step S131 may be performed in units of frames. In this case, the process in step S131 is performed for a predetermined slice in the frame (for example, a slice whose identification number has a predetermined value (for example, “0”) or a slice that is processed first in the frame). It may be performed only in step 1, and the value may be used in other slices. An arbitrary image can be used for calculating the filter coefficient. For example, it may be calculated based on a past frame image.

  Next, an example of the flow of block information generation processing executed in step S132 of FIG. 14 will be described with reference to the flowchart of FIG.

  When the block information generation process is started, the processing target slice area specifying unit 141 specifies the area of the processing target slice in step S151.

  In order to know the area of the slice to be processed, it is known by knowing the macroblock contained in the slice and then knowing the pixels contained in the macroblock. The processing target slice area specifying unit 141 obtains the first macroblock address of the slice from the slice header.

  Here, the head macroblock address is a number assigned to the macroblock in the raster scan order from the upper left of the screen. As shown in FIG. 5, the macro block address at the upper left of the image (frame 151) is 0. Since slice 0 starts from the upper left of the frame 151, the macroblock address of the first macroblock 156-1 of slice 0 is 0. According to this order, the macroblock address of the last macroblock 156-2 of slice 0 is set to E0. Similarly to slice 0, the macroblock address of the first macroblock 157-1 of slice 1 is S1, and the macroblock address of the last macroblock 157-2 is E1. Furthermore, the macroblock address of the first macroblock 158-1 of slice 2 is set to S2, and the macroblock address of the last macroblock 158-2 is set to E2.

  When the slice is decoded, one macroblock address is added every time decoding processing of one macroblock is completed, and eventually the final macrobook of the slice is reached. A flag which is the last macroblock of the slice is set in the last macroblock. As a result, all the macroblock addresses held by the slice can be known. That is, from the first macro block address to the last macro block address.

  By the way, the image size of one frame is indicated by the number of macro blocks in the sequence parameter set (SPS (Sequence Parameter Set)) of the AVC stream (image compression information). pic_height_in_map_units_minus1 indicates the number of macroblocks in the vertical direction of the image. pic_width_in_mbs_minus1 indicates the number of macroblocks in the horizontal direction of the image.

  Therefore, the position of the macro block from the macro block address is expressed by the following equations (2) and (3).

mbx = macro block address% pic_width_in_mbs_minus1 (2)
mby = floor [macro block address / pic_width_in_mbs_minus1] (3)

  In Expression (2) and Expression (3), mbx indicates the number of the macroblock from the left, and mby indicates the number of the macroblock from the top. Further, floor [z] rounds down the decimal part of z to an integer, and A% B indicates the remainder obtained by dividing A by B.

  If the size of the macroblock is determined to be 16 × 16 pixels, the vertical and horizontal positions of the upper left pixel of the macroblock are (16 × mbx, 16 × mby) and are included in the macroblock. The pixel is a pixel included in a range of 16 pixels downward from the pixel position at the upper left and 16 pixels rightward. Up to this point, all the pixels of the slice are known. That is, the area of the processing target slice is specified.

  In step S152 in FIG. 15, the ALF block setting unit 142 determines the ALF block size. In step S153, the ALF block setting unit 142 determines the number of ALF blocks in the frame. Since the image size of the frame is determined in advance, when the ALF block size is determined, the number of ALF blocks (number of ALF blocks in the frame) necessary to spread the ALF block starting from the upper left of the frame is also calculated. Can do. Since the set values for the vertical size (number of pixels) and the horizontal size (number of pixels) of the ALF block are prepared in advance, the ALF block setting unit 142 determines the size of each ALF block and the ALF block according to the set values. The number is determined and an ALF block is placed on the decoded image.

  The number of ALF blocks is calculated by the following formulas (4) and (5).

num_alf_block_x = floor [(16 × (pic_width_in_mbs_minus1 + 1) + (alf_block_size−1))
/ Alf_block_size] (4)
num_alf_block_y = floor [(16 × (pic_height_in_map_units_minus1 + 1)
+ (Alf_block_size−1)) / alf_block_size] (5)

  In Expression (4) and Expression (5), num_alf_block_x and num_alf_block_y are the horizontal and vertical numbers of ALF blocks included in the image, respectively. Alf_block_size indicates the size of one side of the ALF block. Here, for simplification of description, the ALF block is assumed to be a square. Of course, the vertical size and the horizontal size of the ALF block may be different from each other.

  In step S154, the processing target ALF block area specifying unit 143 determines a processing target ALF block. In step S155, the processing target ALF block area specifying unit 143 specifies the area of the processing target ALF block.

  The position of the i-th ALF block is expressed by the following equations (6) and (7).

alf_block_x = i% (num_alf_block_x−1) (6)
alf_block_y = floor [i / (num_alf_block_x−1)] (7)

  In Expression (6) and Expression (7), alf_block_x and alf_block_y indicate the number of the i-th ALF block in the horizontal direction and the vertical direction, respectively. The position of the upper left pixel of the i-th ALF block is a position obtained by multiplying each of alf_block_x and aof_block_y by alf_block_size. That is, the horizontal direction is 16 × alf_block_x, and the vertical direction is 16 × alf_block_y. Therefore, the area of the i-th ALF block is a range of alf_block_size × alf_block_size from the upper left pixel.

  In step S156, the determination unit 144 determines whether or not the region of the processing target slice is included in the region of the processing target ALF block specified as described above.

  If it is determined that the area of the processing target slice is included in the area of the processing target ALF block, the process proceeds to step S157. In step S157, the filter block flag generation unit 145 generates a filter block flag for the ALF block because the processing target ALF block is an ALF block necessary for the processing target slice. In step S158, the filter block flag generation unit 145 outputs the generated filter block flag.

  When the process of step S158 ends, the process proceeds to step S159. If it is determined in step S156 that the area of the processing target slice is not included in the area of the processing target ALF block, the ALF block is unnecessary for the processing target slice, and the process proceeds to step S159.

  In step S159, the processing target ALF block area specifying unit 143 determines whether or not all intra-frame ALF blocks have been processed. If it is determined that the processing has not been performed, the process returns to step S154 to process a new ALF block. Repeat the process after that. Each time the loop processing is repeated, the processing target ALF block area specifying unit 143 sets an ALF block from the group of ALF blocks spread in the area of the frame as a processing target ALF block in the order of raster scanning from the upper left ALF block. Select one by one.

  If it is determined in step S159 that all the ALF blocks in the frame have been processed, the block information generation process ends, the process returns to step S132 in FIG. 14, the control information generation process ends, and the process proceeds to step S110 in FIG. Returning, the process after step S111 is performed.

  In the above description, when the ALF block is arranged so as to cover the frame image area, the upper left corner of the frame is used as the origin, but the position of the origin is arbitrary. For example, it may be the lower left, lower right, upper right, or center of the frame. However, the position of the origin and the way of arranging the ALF blocks need to be determined in advance so as to be common to the encoding process and the decoding process.

  In the above description, the order in which the processing target ALF blocks are selected is described as the raster scan order from the upper left, but the selection order and the start position are arbitrary.

  Next, an example of the flow of adaptive filter processing executed in step S111 in FIG. 13 will be described with reference to the flowchart in FIG.

  When the adaptive filter process is started, the decoded image of the processing target slice is supplied to the adaptive filter 172 and the selection unit 173. In step S171, the control unit 171 specifies the area of the processing target slice. As in the case of the process of step S151 in FIG. 15, the control unit 171 acquires the head macroblock address of the slice in the slice header, detects a flag indicating the last macroblock, and determines the last macroblock address from the head macroblock address. The area up to the macro block address is specified as the area of the processing target slice.

  In step S 172, the control unit 171 acquires the filter coefficient generated by the control information generation unit 112 and sets the filter coefficient in the adaptive filter 172. In step S173, the control unit 171 acquires the ALF block size determined by the control information generation unit 112, and sets (places) the ALF block having the ALF block size over the entire frame area.

  In step S174, the control unit 171 determines one of the unprocessed ALF blocks among the set ALF block groups as described above as a processing target ALF block as in the case of step S154 in FIG. To do. The selection order of the ALF blocks is determined in advance and is the same as the selection order in the control information generation unit 112.

  In step S175, the control unit 171 identifies the determined region of the processing target ALF block in the same manner as in step S155 of FIG.

  In step S176, the control unit 171 determines whether the area of the processing target slice is included in the area of the processing target ALF block, as in the case of step S156 of FIG. If it is determined that it is included, the process proceeds to step S177.

  In step S177, the control unit 171 acquires the filter block flag of the processing target ALF block generated by the control information generation unit 112. Since the control information generation unit 112 generates the filter block flag as described above, actually, the filter block flag is supplied only for the ALF block including the area of the processing target slice. Since the processing order of the ALF block is common to the control information generation unit 112, the filter block flag is supplied in the processing order of the ALF block. Therefore, the control unit 171 can acquire (adopt) the filter block flag of the processing target ALF block by acquiring (adopting) the filter block flag in the supply order.

  Note that the supply timing of the filter block flag and the acquisition timing of the filter block flag by the control unit 171 do not have to coincide with each other. That is, the control unit 171 temporarily holds the filter block flag supplied from the control information generation unit 112, for example, in a built-in buffer or the like, and reads the filter block flag from the buffer in the process of step S177. Also good. Even in this case, the control unit 171 simply sets the reading order of the filter block flag to be the same as the order supplied from the control information generating unit 112, that is, the order of accumulation in the buffer. A filter block flag can be obtained.

  In step S178, the control unit 171 determines whether or not the value of the filter block flag is 1. If the value of the filter block flag is 1 and it is instructed to perform the filter process for the area of the processing target ALF block, the process proceeds to step S179. In step S179, the adaptive filter 172 is controlled by the control unit 171 to perform filter processing on the processing target ALF block. When the process of step S179 ends, the process proceeds to step S180. In this case, the selection unit 173 is controlled by the control unit 171 to select the output of the adaptive filter 172 and outputs it to the frame memory 114 in step S180. That is, the decoded image (partial region) that has been subjected to the filter process is accumulated in the frame memory 114. When the process of step S180 ends, the process proceeds to step S181.

  In step S178, when the value of the filter block flag is 0, and it is instructed not to perform the filter process for the area of the processing target ALF block, the process of step S179 is omitted, and the process proceeds to step S180. In this case, in step S180, the selection unit 173 is controlled by the control unit 171 to select the output of the deblocking filter 111 and outputs it to the frame memory 114. That is, the decoded image (part of the region) that has not been filtered is accumulated in the frame memory 114. When the process of step S180 ends, the process proceeds to step S181.

  If it is determined in step S176 that the region of the processing target slice is not included in the region of the processing target ALF block, the processing target ALF block is an ALF block that is not related to the processing target slice, and thus steps S177 to S177 are performed. The process of step S180 is omitted, and the process proceeds to step S181.

In step S181, the control unit 171 determines whether or not all intra-frame ALF blocks have been processed. If it is determined that there is an unprocessed ALF block, the process returns to step S174, and the subsequent processing is repeated for the new process target ALF block. Each time this loop processing is repeated, the control unit 171 selects ALF blocks from the group of ALF blocks spread in the frame area as processing target ALF blocks one by one in the raster scan order from the upper left ALF block. .
If it is determined in step S181 that all the ALF blocks in the frame have been processed, the adaptive filter process is terminated, the process returns to step S111 in FIG. 13, and the processes after step S112 are performed.

  By performing the adaptive filter processing as described above, the adaptive filter processing unit 113 sets the filter block flags of some ALF blocks in the frame, which are necessary for the processing target slice among the plurality of slices formed in the frame. Based on this, it is possible to appropriately execute the filter processing on the processing target slice. As a result, the adaptive filter processing unit 113 can reduce block distortion that cannot be removed by the deblocking filter and distortion due to quantization of the processing target slice.

  Next, an example of the flow of lossless encoding processing executed in step S116 of FIG. 13 will be described with reference to the flowchart of FIG.

  When the lossless encoding process is started, in step S191, the encoding unit 181 of the lossless encoding unit 106 sequentially encodes the supplied image data (quantized coefficient data), thereby processing target slices. Is encoded to generate encoded data.

  In step S192, the encoded data holding unit 182 holds the encoded data generated in step S191. In step S193, the control information holding unit 183 holds the control information corresponding to the slice (processing target slice) to which the encoded data belongs, supplied from the control information generating unit 112.

  The processes in steps S191 to S193 as described above are performed for each slice in the frame. When the processing for one slice is completed, in step S194, the control information adding unit 184 determines whether or not the encoding unit 181 has encoded image data (quantized coefficient data) for all slices in the frame. judge. If it is determined that there is an unprocessed slice, the process returns to step S191, and the subsequent processing is repeated.

  If the encoding unit 181 determines in step S194 that all slices in the frame have been encoded, the process proceeds to step S195.

  In step S195, the control information adding unit 184 first transmits the control information held in the control information holding unit 183 of the encoded data for one frame held in the encoded data holding unit 182. Embed in the slice header of the slice. At this time, the control information adding unit 184 acquires and summarizes the control information held in the control information holding unit 183, and generates control information for one picture of the frame (picture) to which the encoded data belongs. The control information adding unit 184 embeds the control information for one picture in the slice header.

  That is, in one frame of encoded data composed of a plurality of slices, control information (filter coefficient, ALF block size, filter block flag, etc.) for one frame (picture) is included in one slice header. Added (embedded).

  That is, control information of a plurality of slices is added to one slice header (control information of other slices is also added). When control information is divided into slices and embedded in a plurality of slice headers, overlapping information is generated in each control information. However, the control information adding unit 184 thus provides control information for one frame as one slice header. Therefore, such redundancy can be reduced and encoding efficiency can be improved.

  Here, “add” indicates that control information is associated with encoded data in an arbitrary form. For example, it may be described as a syntax of encoded data or may be described as user data. Further, block information may be linked to encoded data as metadata. That is, “addition” includes “embedding”, “description”, “multiplexing”, “concatenation”, and the like.

  The control information adding unit 184 that has added the control information to the encoded data outputs the encoded data in a predetermined order in step S196. When the encoded data for one picture is output, the lossless encoding unit 106 ends the lossless encoding process, returns to step S116 in FIG. 13, and proceeds to the processes after step S117.

  By performing the lossless encoding process as described above, the image encoding apparatus 100 can suppress a reduction in encoding efficiency due to local control of filter processing at the time of encoding or decoding. For example, even when each frame of an image is processed by being divided into a plurality of slices, the image encoding device 100 can suppress a decrease in encoding efficiency.

<2. Second Embodiment>
[Device Configuration]
Next, an image decoding apparatus corresponding to the image encoding apparatus 100 described in the first embodiment will be described. FIG. 18 is a block diagram showing a configuration example of an embodiment of an image decoding apparatus as an image processing apparatus to which the present invention is applied.

  The image decoding device 200 decodes the encoded data output from the image encoding device 100 and generates a decoded image.

  The image decoding apparatus 200 includes a storage buffer 201, a lossless decoding unit 202, an inverse quantization unit 203, an inverse orthogonal transform unit 204, a calculation unit 205, and a deblocking filter 206. Further, the image decoding apparatus 200 includes an adaptive filter processing unit 207. Furthermore, the image decoding apparatus 200 includes a screen rearrangement buffer 208 and a D / A (Digital / Analog) conversion unit 209. In addition, the image decoding device 200 includes a frame memory 210, an intra prediction unit 211, a motion compensation unit 212, and a selection unit 213.

  The accumulation buffer 201 accumulates transmitted image compression information. The lossless decoding unit 202 decodes the information supplied from the accumulation buffer 201 and encoded by the lossless encoding unit 106 in FIG. 1 by a method corresponding to the encoding method of the lossless encoding unit 106.

  If the macroblock is intra-coded, the lossless decoding unit 202 extracts the intra prediction mode information stored in the header portion of the encoded data and transmits it to the intra prediction unit 211. If the macroblock is inter-coded, the lossless decoding unit 202 extracts the motion vector information stored in the header portion of the encoded data and transfers the motion vector information to the motion compensation unit 212.

  In addition, the lossless decoding unit 202 controls control information for one picture for adaptive filter (control information generated by the control information generation unit 112) from the slice header of the slice supplied first in the frame of the encoded data. Is extracted and supplied to the adaptive filter processing unit 207.

  The inverse quantization unit 203 inversely quantizes the image decoded by the lossless decoding unit 202 by a method corresponding to the quantization method of the quantization unit 105 in FIG. The inverse orthogonal transform unit 204 performs inverse orthogonal transform on the output of the inverse quantization unit 203 by a method corresponding to the orthogonal transform method of the orthogonal transform unit 104 in FIG.

  The calculation unit 205 adds the predicted image supplied from the selection unit 213 to the difference information subjected to inverse orthogonal transform, and generates a decoded image. The deblocking filter 206 removes block distortion of the decoded image generated by the addition process.

  The adaptive filter processing unit 207 is supplied from the deblocking filter 206 based on information such as a filter coefficient, an ALF block size, and a filter block flag included in the control information for one picture supplied from the lossless decoding unit 202. Filter the image. The adaptive filter processing unit 207 performs the same adaptive filter processing as the adaptive filter processing unit 113 in FIG. As a result, the adaptive filter processing unit 207 can reduce block distortion that cannot be removed by the deblocking filter 206 and distortion due to quantization.

  The adaptive filter processing unit 207 supplies the filtered image to the frame memory 210, accumulates it as reference image information, and outputs it to the screen rearrangement buffer 208.

  The screen rearrangement buffer 208 rearranges images. That is, the order of frames rearranged for the encoding order by the screen rearrangement buffer 102 in FIG. 1 is rearranged in the original display order. The D / A conversion unit 209 performs D / A conversion on the image supplied from the screen rearrangement buffer 208 and outputs it. For example, the D / A conversion unit 209 outputs an output signal obtained by D / A conversion to a display (not shown) to display an image.

  The intra prediction unit 211 generates a prediction image based on the information supplied from the lossless decoding unit 202 and outputs the generated prediction image to the selection unit 213 when the frame is intra-coded. .

  When the frame is inter-encoded, the motion compensation unit 212 performs motion compensation processing on the reference image information stored in the frame memory 210 based on the motion vector information supplied from the lossless decoding unit 202. Do.

  When the macroblock is an intra-coded block, the selection unit 213 connects to the intra prediction unit 211 and supplies the image supplied from the intra prediction unit 211 to the calculation unit 205 as a predicted image. When the macroblock is inter-coded, the selection unit 213 connects to the motion compensation unit 212 and supplies the image supplied from the motion compensation unit 212 to the calculation unit 205 as a predicted image.

  FIG. 19 is a block diagram illustrating a detailed configuration example of the lossless decoding unit 202 of FIG. For convenience of explanation, description of the configuration related to extraction of intra prediction mode information and motion vector information is omitted.

  As illustrated in FIG. 19, the lossless decoding unit 202 includes a control information extraction unit 221 and a decoding unit 222. The control information extraction unit 221 acquires encoded data from the accumulation buffer 201, extracts control information for one picture from the slice header of the first slice supplied in the frame, and supplies the control information to the adaptive filter processing unit 207. .

  The decoding unit 222 decodes the encoded data supplied from the control information extraction unit 221 with a decoding method corresponding to the encoding method of the lossless encoding unit 106, and generates decoded data (quantized coefficient data). . The decoding unit 222 supplies the generated decoded data to the inverse quantization unit 203.

  Thus, since the control information extraction unit 221 extracts the control information embedded in the slice header of the encoded data and supplies it to the adaptive filter processing unit 207, the adaptive filter processing unit 207, based on the control information, Appropriate adaptive filtering can be performed. That is, the adaptive filter processing unit 207 can perform adaptive filter processing in the same manner as the adaptive filter processing unit 113 of the image encoding device 100.

[Process flow]
An example of the flow of decoding processing executed by the image decoding apparatus 200 will be described with reference to the flowchart of FIG.

  In step S201, the accumulation buffer 201 accumulates the transmitted image (encoded data). In step S202, the lossless decoding unit 202 performs lossless decoding processing for losslessly decoding the encoded data supplied from the accumulation buffer 201.

  Although details will be described later, the I picture, the P picture, and the B picture encoded by the lossless encoding unit 106 in FIG. 1 are decoded by this lossless decoding process. At this time, extraction of motion vector information, reference frame information, prediction mode information (information indicating an intra prediction mode or an inter prediction mode), and the like is also performed.

  That is, when the prediction mode information is intra prediction mode information, the prediction mode information is supplied to the intra prediction unit 211. When the prediction mode information is inter prediction mode information, motion vector information and reference frame information corresponding to the prediction mode information are supplied to the motion compensation unit 212.

  Also, by this lossless decoding process, control information for adaptive filter processing for one picture is extracted from the slice header of the encoded data, and is supplied to the adaptive filter processing unit 207.

  In step S203, the inverse quantization unit 203 inversely quantizes the transform coefficient decoded in step S202 with characteristics corresponding to the characteristics of the quantization unit 105 in FIG. In step S204, the inverse orthogonal transform unit 204 performs inverse orthogonal transform on the transform coefficient inversely quantized by the process in step S203 with characteristics corresponding to the characteristics of the orthogonal transform unit 104 in FIG. As a result, the difference information corresponding to the input of the orthogonal transform unit 104 (output of the calculation unit 103) in FIG. 1 is decoded.

  In step S205, the calculation unit 205 adds the prediction image selected in the process of step S211 described later to the difference information. As a result, the original image is decoded. In step S <b> 206, the deblock filter 206 filters the image output from the calculation unit 205. Thereby, block distortion is removed.

  In step S207, the adaptive filter processing unit 207 further performs adaptive filter processing on the image subjected to the deblocking filter processing. This adaptive filter processing is the same as the processing performed by the adaptive filter processing unit 113 in FIG. That is, this adaptive filter process is performed in the same manner as described with reference to the flowchart of FIG. 16 except that the control information supplied from the lossless decoding unit 202 is used. However, the control information supplied from the lossless decoding unit 202 is also generated by the control information generation unit 112 in FIG. 1 and is substantially used by the adaptive filter processing unit 113 in FIG. 1. This is equivalent to the control information supplied by the user.

  By this adaptive filter processing, it is possible to reduce block distortion and quantization distortion that could not be removed by deblocking filter processing.

  In step S208, the frame memory 210 stores the filtered image.

  When the intra prediction mode information is supplied, the intra prediction unit 211 performs intra prediction processing in the intra prediction mode in step S209. When inter prediction mode information is supplied, the motion compensation unit 212 performs inter prediction mode motion compensation processing in step S210.

  In step S211, the selection unit 213 selects a predicted image. That is, one of the prediction image generated by the intra prediction unit 211 or the prediction image generated by the motion compensation unit 212 is selected, and the selected prediction image is supplied to the calculation unit 205.

  For example, in the case of an intra-coded image, the selection unit 213 selects the prediction image generated by the intra prediction unit 211 and supplies the selected prediction image to the calculation unit 205. In the case of an inter-coded image, the selection unit 213 selects the predicted image generated by the motion compensation unit 212 and supplies the selected prediction image to the calculation unit 205.

  In step S212, the screen rearrangement buffer 208 performs rearrangement. That is, the order of frames rearranged for encoding by the screen rearrangement buffer 102 of the image encoding device 100 in FIG. 1 is rearranged in the original display order.

  In step S213, the D / A converter 209 D / A converts the image from the screen rearrangement buffer 208. This image is output to a display (not shown), and the image is displayed.

  As described above, in the image decoding device 200, the lossless decoding unit 202 extracts and decodes the control information supplied from the image encoding device 100, and the adaptive filter processing unit 207 uses the control information to decode the image code. The adaptive filter processing is performed in the same manner as the adaptive filter processing unit 113 of the conversion apparatus 100.

  Next, an example of the flow of lossless decoding processing executed in step S202 of FIG. 20 will be described with reference to the flowchart of FIG.

  When the lossless decoding process is started, the control information extraction unit 221 determines in step S231 whether the supplied encoded data is the first transmitted slice of the frame (picture).

  For example, if the frame number (frame_num) is different from the previous slice, that slice is the first slice of the picture. Further, for example, when a flag (field_pic_flag) indicating whether it is a frame picture or a field picture is different from the previous slice, that slice is the first slice of the picture. Furthermore, for example, when the flag (bottom_field_flag) indicating whether the field is the top field or the bottom field is different from the previous slices, the slice is the first slice of the picture. For example, when the frame number (frame_num) is the same and the value of the picture order count POC is different from the previous slice, that slice is the first slice of the picture. Further, for example, when the nal_ref_idc information is different from the previous slice, the slice is the first slice of the picture. Also, if the IDR picture has idr_pic_idc information different from the previous slice, that slice is the first slice of the picture.

  Therefore, the control information extraction unit 221 refers to these values, and when any value is different from the previous slices, the control information extraction unit 221 determines that the slice is the first slice of the picture.

  Of course, the control information extraction unit 221 may determine whether the slice is the first transmitted slice based on other information.

  If it is determined in step S231 that the slice is transmitted at the beginning of the frame, the process proceeds to step S232. In step S232, the control information extraction unit 221 extracts control information for one picture from the slice header, and supplies the control information to the adaptive filter processing unit 207.

  If control information is extracted, it will progress to step S233. If it is determined in step S231 that the supplied encoded data is not the first transmitted slice of the frame (picture), the process proceeds to step S233.

  In step S233, the decoding unit 222 decodes the processing target slice of the encoded data. In step S234, the decoding unit 222 outputs the decoded data (quantized coefficient data) obtained by decoding to the inverse quantization unit 203. In step S235, the decoding unit 222 determines whether all slices in the frame have been processed. If it is determined that there is an unprocessed slice, the process returns to step S231, and the subsequent processing is repeated. If it is determined in step S235 that all the slices in the frame have been processed, the lossless decoding process is terminated, the process returns to step S207 in FIG. 20, and the processes after step S208 are executed.

  By performing the lossless decoding process as described above, the lossless decoding unit 202 can extract the control information added to the encoded data and supply the control information to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately. As a result, the adaptive filter processing unit 207 can reduce block distortion that cannot be removed by the deblocking filter and distortion due to quantization of the slice to be processed.

  At this time, as described above, the control information is embedded in the slice header of the first slice of the picture, and the control information extraction unit 221 appropriately detects the first slice of the picture, Control information for one picture is extracted from the slice header.

  By doing so, the adaptive filter processing unit 207 can prepare control information of the picture at the time of processing the first slice, and can perform adaptive filter processing without unnecessary delay. That is, when performing adaptive filter processing on each slice, there is no need to provide unnecessary waiting time for preparation of control information, so the adaptive filter processing unit 207 embeds control information in each slice header. Adaptive filter processing can be performed in the same processing time.

  Therefore, the image decoding apparatus 200 can suppress a reduction in encoding efficiency due to local control of filter processing. For example, even when each frame of an image is processed by being divided into a plurality of slices, a reduction in encoding efficiency can be suppressed.

<3. Third Embodiment>
[Overview of an example of including control information in the header of the first slice]
In the above description, the control information for one picture has been described as being added to the slice header of the slice to be output (transmitted) first, but the control information is added to the slice header of another slice. You may do it. For example, control information may be added to the slice header of the first slice.

  The head slice is, for example, the slice located at the top of the frame (picture). Also, for example, the head slice is the slice with the smallest slice identification number. Further, for example, the head slice is a slice including a macroblock whose MB address is “0”. In general, these slices are all the same slice, but they do not have to match. In that case, the head slice is determined based on any one of the conditions.

  That is, as described in the first embodiment and the second embodiment, the first transmitted slice is a slice specified by the processing order, whereas this first slice has its positional relationship. It is a slice specified by (for example, an identification number or coordinates).

  For example, as shown in FIG. 22, in a frame 151 composed of three slices (slice 0, slice 1, and slice 2), assume that slice 0 is set as the first slice.

  At this time, the control information 191-1 to control information 191-3 generated for each slice are all added to the slice 0 header 192-2, which is the slice header of the first slice, regardless of the slice processing order. . The first MB address of this slice 0 is 0. Therefore, in this case, the control information extraction unit 221 refers to the value of first_mb_in_slice (information defining the first MB address in the slice) in the slice header, and if the value is “0”, the control information is extracted thereafter. It turns out that it contains. Therefore, the control information extraction unit 221 can easily confirm the presence of the control information and extract it without the boundary inspection.

  However, as shown in FIG. 22, the first slice is not always transmitted first. In the case of the example in FIG. 22, the encoded data 194 is transmitted in the order of slice 1, slice 0, and slice 2.

  Therefore, in this case, the adaptive filter processing unit 207 performs adaptive filter processing for the slice transmitted before the head slice (slice 0 in the example of FIG. 22) until control information is extracted from the head slice. I can't.

[Encoding side]
The configuration of the lossless encoding unit 106 of the image encoding device 100 in this case is the same as that of the first embodiment described with reference to FIG.

  An example of the flow of lossless encoding processing in this case will be described with reference to the flowchart of FIG. The flowchart of FIG. 23 corresponds to the flowchart shown in FIG.

  In this case as well, processing is basically performed in the same manner as in the first embodiment. That is, when the lossless encoding process is started in step S116 in FIG. 13, the processes in steps S251 to S254 are executed in the same manner as the processes in steps S191 to S194 in FIG. Data is encoded for each slice.

  In step S255, the control information adding unit 184 converts the control information held in the control information holding unit 183 into the slice header of the first slice of the encoded data for one frame held in the encoded data holding unit 182. Embed in. At this time, the control information adding unit 184 acquires and summarizes the control information held in the control information holding unit 183, and generates control information for one picture of the frame (picture) to which the encoded data belongs. The control information adding unit 184 embeds the control information for one picture in the slice header of the first slice.

  In step S256, the control information adding unit 184 that has added the control information to the encoded data outputs the encoded data in a predetermined order. When the encoded data for one picture is output, the lossless encoding unit 106 ends the lossless encoding process, returns to step S116 in FIG. 13, and proceeds to the processes after step S117.

  By performing the lossless encoding process as described above, the image encoding apparatus 100 can suppress a reduction in encoding efficiency due to local control of the filter process, as in the case of the first embodiment. it can. Further, it is possible to easily extract control information at the time of decoding.

[Decryption side]
Next, the image decoding apparatus 200 of this Embodiment is demonstrated. FIG. 24 is a block diagram illustrating a configuration example of the lossless decoding unit 202 of the image decoding device 200 in this case. As shown in FIG. 24, the lossless decoding unit 202 in this case has basically the same configuration as the lossless decoding unit 202 in the second embodiment described with reference to FIG.

  However, in this case, the lossless decoding unit 202 further includes a decoded data holding unit 223. The decoded data holding unit 223 holds the decoded data generated by being decoded by the decoding unit 222.

  When the control information is included in the slice header of the first slice, as described above, the control information cannot be obtained until the first slice is transmitted. Therefore, the decoded data holding unit 223 holds the decoded data of the slice transmitted before the head slice until control information is obtained.

  Next, an example of the flow of the lossless decoding process in this case executed in step S202 of FIG. 20 will be described with reference to the flowchart of FIG. The flowchart of FIG. 25 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the second embodiment. That is, when the lossless decoding process is started, the control information extraction unit 221 determines in step S271 whether or not the supplied encoded data is the first slice of a frame (picture).

  For example, if the value of first_mb_in_slice in the slice header is “0” and it is determined that the slice is the first slice, the process proceeds to step S272. In step S <b> 272, the control information extraction unit 221 extracts control information for one picture from the slice header, and supplies the control information to the adaptive filter processing unit 207.

  If control information is extracted, it will progress to step S273. If it is determined in step S271 that the supplied encoded data is not the first slice, the process proceeds to step S273.

  In step S273, when the encoded data is decoded by the decoding unit 222, the decoded data holding unit 223 holds the decoded data obtained by decoding in step S274.

  In step S275, the decoded data holding unit 223 determines whether or not control information is extracted by the control information extracting unit 221. If it is determined that the extracted data has been extracted, the decoded data holding unit 223 proceeds to step S276 and starts outputting the held decoded data to the inverse quantization unit 203.

  When the output of the decoded data is started, the process proceeds to step S277. If it is determined in step S275 that control information has not been extracted for the current frame being processed, the process proceeds to step S277.

  In step S277, the control information extraction unit 221 determines whether all slices in the frame have been processed. If it is determined that there is an unprocessed slice, the process returns to step S271, and the subsequent processing is repeated for the unprocessed slice. If it is determined in step S277 that all slices in the frame have been processed, the lossless decoding process is terminated, the process returns to step S207 in FIG. 20, and the processes after step S208 are executed.

  By performing the lossless decoding process as described above, the lossless decoding unit 202 can extract the control information added to the encoded data and supply the control information to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately. As a result, the adaptive filter processing unit 207 can reduce block distortion that cannot be removed by the deblocking filter and distortion due to quantization of the slice to be processed.

  At this time, as described above, the control information is embedded in the slice header of the first slice of the picture, and the control information extraction unit 221 easily detects the first slice of the picture, and the slice header From this, control information for one picture can be extracted.

<4. Fourth Embodiment>
[Overview of an example of including control information in the header of a predetermined slice]
The control information may be added to the slice headers of slices other than the first transmitted slice and the first slice described above.

  For example, as shown in FIG. 26, in a frame 151 composed of three slices (slice 0, slice 1, and slice 2), slice 0 is set as the first slice.

  At this time, control information 191-1 to control information 191-3 generated for each slice are all slices that are slice headers of slice 2, which is a predetermined slice, regardless of the slice processing order. 2 may be added to the header 192-3.

  The identification method of this slice 2 (slice 2 header 192-3) is arbitrary. In this case, the control information detection method of the control information extraction unit 221 of the image decoding device 200 is also arbitrary.

  Also in this case, as in the case of the third embodiment, the slice in which the control information is embedded is not always transmitted first. In the case of the example of FIG. 26, the encoded data 194 is transmitted in the order of slice 1, slice 0, and slice 2. That is, slice 0 and slice 1 are transmitted before slice 2 including control information.

  Therefore, also in this case, the adaptive filter processing unit 207 performs adaptive filter processing until the control information is extracted from slice 2 for slices transmitted prior to slice 2 (in the case of FIG. 26, slice 0 and slice 1). Processing cannot be performed.

[Encoding side]
The configuration of the lossless encoding unit 106 of the image encoding device 100 in this case is the same as that of the first embodiment described with reference to FIG.

  An example of the flow of the lossless encoding process in this case will be described with reference to the flowchart of FIG. The flowchart of FIG. 27 corresponds to the flowchart shown in FIG.

  In this case as well, processing is basically performed in the same manner as in the first embodiment. That is, when the lossless encoding process is started in step S116 in FIG. 13, the processes in steps S291 to S294 are executed in the same manner as the processes in steps S191 to S194 in FIG. Data is encoded for each slice.

  In step S 295, the control information adding unit 184 converts the control information held in the control information holding unit 183 into a predetermined predetermined amount of encoded data for one frame held in the encoded data holding unit 182. Embed in the slice header of the slice. At this time, the control information adding unit 184 acquires and summarizes the control information held in the control information holding unit 183, and generates control information for one picture of the frame (picture) to which the encoded data belongs. The control information adding unit 184 embeds the control information for one picture in the slice header of a predetermined slice.

  The control information adding unit 184 that has added the control information to the encoded data outputs the encoded data in a predetermined order in step S296. When the encoded data for one picture is output, the lossless encoding unit 106 ends the lossless encoding process, returns to step S116 in FIG. 13, and proceeds to the processes after step S117.

  By performing the lossless encoding process as described above, the image encoding apparatus 100 can suppress a reduction in encoding efficiency due to local control of the filter process, as in the case of the first embodiment. it can.

[Decryption side]
Next, the image decoding apparatus 200 of this Embodiment is demonstrated. In this case, the configuration of the lossless decoding unit 202 of the image decoding device 200 is the same as that of the third embodiment described with reference to FIG.

  An example of the flow of the lossless decoding process in this case, which is executed in step S202 of FIG. 20, will be described with reference to the flowchart of FIG. The flowchart of FIG. 28 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the third embodiment. That is, when the lossless decoding process is started, in step S311, the control information extraction unit 221 supplies the encoded data that is a predetermined slice of a frame (picture) (a slice including the control information in the slice header). It is determined whether or not.

  If it is determined that the slice is a predetermined slice, the process proceeds to step S312. In step S312, the control information extraction unit 221 extracts control information for one picture from the slice header and supplies the control information to the adaptive filter processing unit 207.

  If control information is extracted, it will progress to step S313. If it is determined in step S311 that the supplied encoded data is not a predetermined slice to which control information is added, the process proceeds to step S313.

  Thereafter, the processes in steps S313 to S317 are executed in the same manner as the processes in steps S273 to S277 in FIG.

  By performing the lossless decoding process as described above, the lossless decoding unit 202 can extract the control information added to the encoded data and supply the control information to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately. As a result, the adaptive filter processing unit 207 can reduce block distortion that cannot be removed by the deblocking filter and distortion due to quantization of the slice to be processed.

<5. Fifth embodiment>
[Overview of example using pointer]
In addition to adding the control information itself to the slice header as described above, the control information may include, for example, a pointer indicating the location where the control information is added to the slice header.

  For example, as shown in FIG. 29, control information 191-1 to control information 191-3 corresponding to slice 0 to slice 2 of frame 151 are collected and encoded data 194 as control information 231 for one picture. Is added after the slice 2 data 193-3. A pointer indicating the position of the control information 231 is added to the slice 1 header 192-1 transmitted first.

  By doing in this way, the control information extraction part 221 of the image decoding apparatus 200 can acquire the control information 231 from the pointer added thereto with reference to the slice 1 header 192-1. That is, the control information extraction unit 231 can extract control information from the encoded data in substantially the same manner as in the second embodiment.

  However, in this case, actually, the control information extraction unit 221 cannot extract the control information 231 until the control information 231 is supplied.

  Of course, the place where the control information 231 is added is arbitrary. For example, the control information may be added to a position that is transmitted before the slice 1 header 192-1. In that case, the control information extraction unit 221 can extract the control information at the time when the pointer of the slice 1 header 192-1 is referred to.

[Encoding side]
Also in this case, the configuration of the lossless encoding unit 106 of the image encoding device 100 is the same as that of the first embodiment described with reference to FIG.

  An example of the flow of lossless encoding processing in this case will be described with reference to the flowchart of FIG. The flowchart of FIG. 30 corresponds to the flowchart shown in FIG.

  In this case as well, processing is basically performed in the same manner as in the first embodiment. That is, when the lossless encoding process is started in step S116 in FIG. 13, the processes in steps S331 to S334 are executed in the same manner as the processes in steps S191 to S194 in FIG. Data is encoded for each slice.

  In step S335, the control information adding unit 184 adds the control information held in the control information holding unit 183 to a predetermined position of the encoded data. At this time, the control information adding unit 184 acquires and summarizes the control information held in the control information holding unit 183, and generates control information for one picture of the frame (picture) to which the encoded data belongs. The control information adding unit 184 adds the control information for one picture to a predetermined position of the encoded data.

  In step S336, the control information adding unit 184 uses the pointer indicating the position to which the control information is added as a slice of the first transmitted slice of the encoded data for one frame held in the encoded data holding unit 182. Embed in header.

  The control information adding unit 184 that adds the control information to the encoded data and embeds the pointer in the slice header outputs the encoded data in a predetermined order in step S337. When the encoded data for one picture is output, the lossless encoding unit 106 ends the lossless encoding process, returns to step S116 in FIG. 13, and proceeds to the processes after step S117.

  By performing the lossless encoding process as described above, the image encoding apparatus 100 can suppress a reduction in encoding efficiency due to local control of the filter process, as in the case of the first embodiment. it can.

[Decryption side]
Next, the image decoding apparatus 200 of this Embodiment is demonstrated. In this case, the configuration of the lossless decoding unit 202 of the image decoding device 200 is the same as that of the third embodiment described with reference to FIG.

  An example of the flow of the lossless decoding process in this case, which is executed in step S202 of FIG. 20, will be described with reference to the flowchart of FIG. The flowchart of FIG. 28 corresponds to the flowchart shown in FIG.

  Next, an example of the flow of the lossless decoding process in this case executed in step S202 of FIG. 20 will be described with reference to the flowchart of FIG. The flowchart of FIG. 31 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the third embodiment. That is, when the lossless decoding process is started, the control information extraction unit 221 determines in step S351 whether the supplied encoded data is the first transmitted slice of the frame (picture).

  If it is determined by the determination in the same manner as in the second embodiment that the slice has been transmitted first, the process proceeds to step S352. In step S352, the control information extraction unit 221 refers to the pointer added to the slice header.

  If the pointer is referred to, the process proceeds to step S353. If it is determined in step S351 that the supplied encoded data is not the slice transmitted at the beginning of the frame, the process proceeds to step S353.

  In step S353, the control information extraction unit 221 determines whether the control information can be extracted at the current time. At that time, if it is determined that the control information for one picture added to the encoded data has already been supplied and can be extracted, the process proceeds to step S354, and the control information extraction unit 221 Control information is extracted and supplied to the adaptive filter processing unit 207.

  If control information is extracted, it will progress to step S355. If it is determined in step S353 that the control information has not been supplied yet and cannot be extracted, the process proceeds to step S355.

  When the decoding unit 222 decodes the processing target slice of the encoded data in step S355, the decoded data holding unit 223 holds the decoded data obtained by decoding in step S356.

  In step S357, the decoded data holding unit 223 determines whether or not the control information is extracted by the control information extraction unit 221. When it is determined that the extracted data has been extracted, the decoded data holding unit 223 proceeds to step S358 and starts outputting the held decoded data to the inverse quantization unit 203.

  When the output of the decoded data is started, the process proceeds to step S359. If it is determined in step S357 that control information has not been extracted for the frame currently being processed, the process proceeds to step S359.

  In step S359, the control information extraction unit 221 determines whether all slices in the frame have been processed. If it is determined that there is an unprocessed slice, the process returns to step S351, and the subsequent processing is repeated for the unprocessed slice. If it is determined in step S359 that all slices in the frame have been processed, the lossless decoding process is terminated, the process returns to step S207 in FIG. 20, and the processes after step S208 are executed.

  By performing the lossless decoding process as described above, the lossless decoding unit 202 can extract control information based on the pointer added to the encoded data and supply the control information to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately. As a result, the adaptive filter processing unit 207 can reduce block distortion that cannot be removed by the deblocking filter and distortion due to quantization of the slice to be processed.

  Therefore, the image decoding apparatus 200 can suppress a reduction in encoding efficiency due to local control of filter processing, as in the case of the second embodiment. For example, even when each frame of an image is processed by being divided into a plurality of slices, a reduction in encoding efficiency can be suppressed.

[Other examples]
In the above description, the pointer indicating the position to which the control information is added has been described as being added to the slice header of the slice transmitted at the beginning of the frame, but the pointer embedding position is arbitrary. For example, control information may be added to the slice header of the first slice as in the third embodiment, or control is performed to a predetermined slice as in the fourth embodiment. Information may be added.

  The pointer described above may be any form of information.

<6. Sixth Embodiment>
[Overview of an example of collecting control information into multiple groups]
In the above description, the control information for one picture has been described as being integrated into one. However, the present invention is not limited to this. For example, one frame slice is divided into a plurality of groups, and the control information is integrated for each group. Also good.

  For example, in FIG. 32, a dotted line in the frame 151 indicates a boundary between slices, and a solid line indicates a group that groups a plurality of slices. The control information of each slice is collected for each group.

  In FIG. 32, control information 241-1 is a summary of control information of slices belonging to the first group from the top of the frame 151. The control information 241-2 is a collection of control information of slices belonging to the second group from the top of the frame 151. The control information 241-3 is a collection of control information of slices belonging to the third group from the top of the frame 151.

  These pieces of control information are embedded in the slice header of the slice that is transmitted first in the corresponding group.

  In FIG. 32, the control information 241-1 is embedded in the slice A header 242-1 which is the slice header of the slice A transmitted first in the encoded data 244-1 of the first group from the top of the frame 151. .

  Similarly, the control information 241-2 is embedded in the slice B header 242-2 which is the slice header of the slice B transmitted first in the encoded data 244-2 of the second group from the top of the frame 151.

  Similarly, the control information 241-3 is embedded in the slice C header 242-3, which is the slice header of the slice C transmitted first, of the encoded data 244-3 of the third group from the top of the frame 151.

  That is, in this case, a plurality of pieces of control information are added to the encoded data for one frame, but since they are grouped in units of groups, the redundancy is higher than when control information is added for each slice. Is reduced, and the coding efficiency is improved. In addition, since control information is added in a plurality of ways, resistance to packet loss at the time of transmission is stronger than in the case of the above-described embodiments.

  Note that this group of slices is determined in advance. That is, the slices in the frame are divided into how many groups, and which slices belong to which groups are determined in advance.

[Encoding side]
The image encoding apparatus 100 in this case will be described. The configuration of the lossless encoding unit 106 of the image encoding device 100 in this case is the same as that of the first embodiment described with reference to FIG.

  An example of the flow of lossless encoding processing in this case will be described with reference to the flowchart of FIG. The flowchart of FIG. 33 corresponds to the flowchart shown in FIG.

  In this case as well, processing is basically performed in the same manner as in the first embodiment. That is, when the lossless encoding process is started in step S116 in FIG. 13, the processes in steps S371 to S374 are executed in the same manner as the processes in steps S191 to S194 in FIG. Data is encoded for each slice.

  In this case, however, the control information adding unit 184 determines whether or not all slices have been encoded in units of groups, not frames, in step S374. That is, the control information adding unit 184 determines whether or not the encoding unit 181 has encoded all slices belonging to the processing target group in step S374.

  If it is determined that there is an unprocessed slice belonging to the processing target group, the process returns to step S371, and the subsequent processing is repeated for the unprocessed slice. If it is determined in step S374 that the encoding unit 181 has encoded all slices belonging to the processing target group, the process proceeds to step S375.

  In step S375, the control information adding unit 184 first transmits the control information held in the control information holding unit 183 of the encoded data for one group held in the encoded data holding unit 182. Embed in the slice header of the slice. At this time, the control information adding unit 184 acquires and summarizes the control information held in the control information holding unit 183, and generates control information (control information for one group) of the group to which the encoded data belongs. The control information adding unit 184 embeds the control information for one group in the slice header of the slice transmitted first in the group.

  In step S376, the control information adding unit 184 that has added the control information to the encoded data outputs the encoded data for one group in a predetermined order. When the encoded data for one group is output, the lossless encoding unit 106 determines whether all the groups in the frame have been processed in step S377.

  If it is determined that there is an unprocessed group, the process returns to step S371, and the subsequent processing is repeated for the unprocessed group. If it is determined in step S377 that all groups in the frame have been processed, the lossless encoding unit 106 ends the lossless encoding process, returns to step S116 of FIG. move on.

  By performing the lossless encoding process as described above, the image encoding apparatus 100 can suppress a reduction in encoding efficiency due to local control of the filter process. In addition, resistance to packet loss and the like can be improved.

[Decryption side]
Next, the image decoding apparatus 200 of this Embodiment is demonstrated. In this case, the lossless decoding unit 202 of the image decoding apparatus 200 may extract control information in units of groups, not in units of frames (pictures). Therefore, the lossless decoding unit 202 in this case has the same configuration as the lossless decoding unit 202 in the second embodiment described with reference to FIG.

  Further, the lossless decoding process by the lossless decoding unit 202 can also be executed in the same manner as the example described with reference to the flowchart of FIG. 21 except that the unit of the frame (picture) is the unit of group.

  As described above, the lossless decoding unit 202 can extract the control information added to the encoded data and supply it to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately.

[Other examples]
In the above description, the control information is described as being added to the slice header of the first transmitted slice of each group, but the control information embedding position is arbitrary. For example, control information may be added to the slice header of the first slice of each group as in the third embodiment, or each group may be determined in advance as in the fourth embodiment. Control information may be added to the predetermined slice.

<7. Seventh Embodiment>
[Overview of an example of controlling the number of groups]
In the sixth embodiment, a group composed of a plurality of slices has been described as a unit for grouping control information. You may make it define. That is, in this case, the image encoding apparatus 100 defines, for example, for each frame, which slice belongs to which group, and how many groups are formed in one frame (how many control information are aggregated per frame). To do.

[Encoding side]
The image encoding apparatus 100 in this case will be described. FIG. 34 is a block diagram illustrating a configuration example of the lossless encoding unit 106 of the image encoding device 100 in this case.

  As shown in FIG. 34, the lossless encoding unit 106 in this case includes an encoding unit 181 to a control information adding unit 184, as in the case of the first embodiment. However, the encoding unit 106 in this case further includes a control unit 251.

  The control unit 251 defines groups and determines the number of groups in the processing target frame. In other words, the control unit 251 determines a data range to which each control information embedded in the encoded data corresponds.

  The control unit 251 controls the encoding unit 181 and the control information adding unit 184 to embed control information corresponding to the group in the slice header of the slice transmitted at the beginning of each group.

  An example of the flow of lossless encoding processing in this case will be described with reference to the flowchart of FIG. The flowchart of FIG. 35 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the sixth embodiment. When the lossless encoding process is started in step S116 of FIG. 13, in step S391, the control unit 251 defines a group for the processing target frame and sets the number of groups. The control unit 251 controls the encoding unit 181 and the control information adding unit 184 based on the setting related to the group.

  Each process of step S392 to step S398 is executed in accordance with the group setting performed in step S391. That is, the processes in steps S392 to S398 after the group is set are executed in the same manner as the processes in steps S371 to S377 in FIG.

  By performing the lossless encoding process as described above, the image encoding apparatus 100 can suppress a reduction in encoding efficiency due to local control of the filter process. In addition, resistance to packet loss and the like can be improved.

[Decryption side]
Next, the image decoding apparatus 200 of this Embodiment is demonstrated. FIG. 36 is a block diagram illustrating a configuration example of the lossless decoding unit 202 of the image decoding device 200 in this case.

  In this case, the lossless decoding unit 202 of the image decoding apparatus 200 extracts control information in units of groups, not in units of frames (pictures). Therefore, as shown in FIG. 36, the lossless decoding unit 202 in this case is similar to the lossless decoding unit 202 in the third embodiment described with reference to FIG. 24, for example, as the control information extraction unit 221. Or a decoded data holding unit 223. However, in this case, since the image decoding apparatus 200 does not grasp the number of groups in the processing target frame, the image decoding apparatus 200 analyzes each slice header and searches for control information. Therefore, in this case, the lossless decoding unit 202 further includes a header analysis unit 261 as illustrated in FIG.

  The header analysis unit 261 refers to each slice header of the supplied encoded data and searches for control information. The control information extraction unit 221 extracts control information based on the analysis result. Each unit performs processing for each group, as in the case of the sixth embodiment.

  Next, an example of the flow of the lossless decoding process in this case executed in step S202 of FIG. 20 will be described with reference to the flowchart of FIG. The flowchart of FIG. 37 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the third embodiment. When the lossless decoding process is started, in step S411, the header analysis unit 261 refers to the slice header of the processing target slice of the supplied encoded data, and determines whether control information exists in the slice header. To do. When it is determined that the processing target slice is the first transmitted slice of the group and the control information of the group is included in the slice header, the process proceeds to step S412.

  In step S412, the control information extraction unit 221 extracts control information for one group from the slice header. If control information is extracted, it will progress to step S413. If it is determined in step S411 that no control information exists in the slice header, the process proceeds to step S413.

  Each process of step S413 thru | or step S417 is performed similarly to each process of step S273 thru | or step S277 of FIG.

  As described above, the lossless decoding unit 202 can extract the control information added to the encoded data and supply it to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately.

[Control the number of groups]
Next, control of the number of groups will be described.

  Generally, when the number of groups is increased (the number of control information per frame is increased), the redundancy of control information increases and the encoding efficiency of encoded data decreases. Thereby, the amount of information to be processed in the image decoding device 200 increases. In addition, the number of times control information is extracted increases. Therefore, the load on the image decoding device 200 may increase. However, since the information amount of one piece of control information is reduced, the required memory amount is reduced.

  On the other hand, the image encoding apparatus 100 can output encoded data in smaller units by increasing the number of groups. That is, the delay time of the encoding process can be reduced. In this case, since the encoded data is output at a high frequency, the required memory amount is reduced.

  Conversely, if the number of groups is reduced (the number of control information per frame is reduced), the redundancy of control information is reduced, and the encoding efficiency of encoded data is improved. Thereby, the amount of information to be processed in the image decoding apparatus 200 is reduced. In addition, the number of times control information is extracted is reduced. Therefore, the load on the image decoding device 200 may be reduced. However, since the amount of information for one piece of control information increases, the amount of memory required increases.

  On the other hand, the image encoding apparatus 100 outputs encoded data in a larger unit by reducing the number of groups. That is, the delay time of the encoding process increases. In this case, since the encoded data is output at a low frequency, the required memory amount increases.

  As described above, various parameters change depending on the increase / decrease of the number of groups. Therefore, the optimum number of groups is determined by system specifications such as hardware resources and usage purposes.

  For example, in the case of a system that stores encoded data generated by the image encoding apparatus 100 in a server or the like and provides the encoded data based on a request from the image decoding apparatus 200, for example, the image encoding apparatus 100 The increase in delay time in the case has little effect on the provision of encoded data. In such a system, priority should be given to suppressing the reduction in the load of the decoding process over the reduction in the delay time of the encoding process.

  In addition, for example, image data generated by shooting or the like is immediately (real-time) encoded by the image encoding device 100, the encoded data is transmitted, and the encoded data is decoded by the image decoding device 200. In the case of a system that displays a decoded image, it is most important to suppress the delay time of each process.

  Moreover, when the processing capability of the image decoding apparatus 200 is low, it is desirable to give priority to suppressing the load of the decoding process. Conversely, when the processing capability of the image encoding device 100 is low, it is desirable to prioritize suppression of the encoding processing load. Further, there may be a case where improvement in encoding efficiency should be given priority depending on the bit rate of image data, the available bandwidth of the transmission path, and the like.

  Thus, the optimum values of various parameters such as delay time, encoding efficiency, processing load, and memory capacity vary depending on the system specifications. Therefore, the control unit 251 sets groups so that various parameters are optimal with respect to system specifications. Thereby, it can apply to a more various system.

  In order to set this group, the image encoding device 100 or the image decoding device 200 collects hardware resources of other devices in the system and information on transmission paths, and collects various information with other devices. It may be exchanged.

  Further, the number of groups in one frame may be any number as long as it is one or more. Further, the control of the number of groups may be other than a frame unit. For example, it may be a GOP unit.

  In the above description, the control information is described as being added to the slice header of the first transmitted slice of each group. However, the embedding position of the control information is arbitrary. For example, control information may be added to the slice header of the first slice of each group as in the third embodiment, or each group may be determined in advance as in the fourth embodiment. Control information may be added to the predetermined slice.

  Furthermore, the image coding apparatus 100 may set a slice (slice header) in which the control information is embedded. For example, such a setting may be performed in an arbitrary unit such as a frame unit or a GOP unit. Moreover, you may make it perform irregularly.

  In each of the embodiments described above, it has been described that control information in a frame is grouped into one or a plurality of units in units of slices, but the unit in which the control information is grouped is arbitrary. For example, a unit smaller than a slice, for example, a macro block may be used as a unit. That is, a plurality of control information for each macroblock may be collected to generate control information for each group.

<8. Eighth Embodiment>
[Outline of an example of grouping elements independently]
In the above description, each element of the filter coefficient, block size, and filter block flag constituting the control information has been described so as to be combined in the same unit. Also good. That is, the filter coefficient, block size, and filter block flag elements may be grouped independently of each other.

  In this case, an image range (slice) to which each group of filter coefficients corresponds, an image range (slice) to which each group of block sizes corresponds, and an image range (slice) of the group to which each filter block flag corresponds Are set independently of each other, slice headers in which such information is stored may be different from each other.

  Therefore, in this case, the image encoding device 100 and the image decoding device 200 need to perform the same processing as in the case of the control information described above for each element of the filter coefficient, the block size, and the filter block flag.

[Encoding side]
The image encoding apparatus 100 in this case will be described. FIG. 38 is a block diagram illustrating a configuration example of the lossless encoding unit 106 of the image encoding device 100 in this case.

  As shown in FIG. 38, the lossless encoding unit 106 in this case includes an encoding unit 181 to a control information holding unit 183, as in the case of the first embodiment. In this case, the encoding unit 106 further includes a control information adding unit 281 instead of the control information adding unit 184.

  The control information adding unit 281 embeds each element of the filter coefficient, block size, and filter block flag in the slice header of the encoded data for each group set independently of each other. The control information adding unit 281 includes a flag adding unit 291, a block size adding unit 292, and a filter coefficient adding unit 293.

  The flag adding unit 291 adds the filter block flag of the processing target flag group to the slice header of the slice transmitted first in the processing target flag group. A flag group is a group of slices corresponding to a set of filter block flags embedded in the same slice header.

  The block size adding unit 292 adds the block size of the processing target block size group to the slice header of the slice transmitted first in the processing target block size group. A block size group is a group of slices corresponding to a set of block sizes embedded in the same slice header.

  The filter coefficient adding unit 293 adds the filter coefficient of the processing target filter coefficient group to the slice header of the slice transmitted first of the processing target filter coefficient group. A filter coefficient group is a group of slices corresponding to a set of filter coefficients embedded in the same slice header.

  With reference to the flowchart of FIG. 39, the example of the flow of the lossless encoding process in this case is demonstrated. The flowchart of FIG. 39 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the sixth embodiment. When the lossless encoding process is started in step S116 in FIG. 13, the processes in steps S431 to S433 are executed in the same manner as the processes in steps S371 to S373 in FIG.

  In step S434, the flag adding unit 291 of the control information adding unit 281 determines whether or not the encoding unit 181 has encoded all slices of the processing target flag group. If it is determined that all slices have been encoded, the process proceeds to step S435.

  In step S435, the flag adding unit 291 embeds the filter block flags for one flag group in the slice header of the slice transmitted first in the processing target flag group.

  When embedding the filter block flag is completed, the process proceeds to step S436. If it is determined in step S434 that there is an unprocessed slice in the processing target flag group, the process proceeds to step S436.

  In step S436, the block size adding unit 292 of the control information adding unit 281 determines whether or not the encoding unit 181 has encoded all slices of the processing target flag group. If it is determined that all slices have been encoded, the process proceeds to step S437.

  In step S437, the block size adding unit 292 embeds the block size for one block size group in the slice header of the slice transmitted first in the processing target block size group.

  When the block size is embedded, the process proceeds to step S438. If it is determined in step S438 that there is an unprocessed slice in the processing target block size group, the process proceeds to step S438.

  In step S438, the filter coefficient adding unit 293 of the control information adding unit 281 determines whether or not the encoding unit 181 has encoded all slices of the processing target filter coefficient group. If it is determined that there is an unprocessed slice, the process returns to step S431, and the subsequent processing is repeated.

  If it is determined in step S438 that all slices have been encoded, the process proceeds to step S439. In step S439, the filter coefficient adding unit 293 embeds filter coefficients for one filter coefficient group in the slice header of the slice that is first transmitted within the processing target filter coefficient group.

  When the embedding of the filter coefficient is completed, the process proceeds to step S440. In step S440, the control information adding unit 281 outputs the encoded data in a predetermined order. In step S441, the lossless encoding unit 106 determines whether all the groups in the frame have been processed. If it is determined that there is an unprocessed group, the process returns to step S431, and the subsequent processing is repeated.

  If it is determined in step S441 that all groups in the frame have been processed, the lossless encoding unit 106 ends the lossless encoding process, returns to step S116 in FIG. move on.

  By performing the lossless encoding process as described above, the lossless encoding unit 106 can add each element of the control information in a unit more appropriate for each. Thereby, the image coding apparatus 100 can more appropriately control various elements such as coding efficiency, delay time, load amount, and the like.

[Decryption side]
Next, the image decoding apparatus 200 of this Embodiment is demonstrated. In this case, the lossless decoding unit 202 of the image decoding apparatus 200 extracts each element of the filter coefficient, the block size, and the filter block flag in units of groups, not in units of frames (pictures).

  FIG. 40 is a block diagram illustrating a configuration example of the lossless decoding unit 202 of the image decoding device 200 in this case. As shown in FIG. 40, the lossless decoding unit 202 in this case includes a decoding unit 222 and a decoded data holding unit 223, as in the case of the third embodiment. In this case, the decoding unit 222 further includes a control information extraction unit 301 instead of the control information extraction unit 221.

  The control information extraction unit 301 extracts each element of the filter coefficient, the block size, and the filter block flag from the slice header of the encoded data. The control information extraction unit 301 includes a flag extraction unit 311, a block size extraction unit 312, and a filter coefficient extraction unit 313.

  The flag extraction unit 311 extracts the filter block flag of the processing target flag group from the slice header of the slice transmitted first of the processing target flag group.

  The block size extraction unit 312 extracts the block size of the processing target block size group from the slice header of the slice transmitted first of the processing target block size group.

  The filter coefficient extraction unit 313 extracts the filter coefficient of the processing target filter coefficient group from the slice header of the slice transmitted first of the processing target filter coefficient group.

  Next, an example of the flow of the lossless decoding process in this case executed in step S202 of FIG. 20 will be described with reference to the flowchart of FIG. The flowchart in FIG. 41 corresponds to the flowchart shown in FIG.

  In this case as well, processing is performed basically in the same manner as in the second embodiment. That is, when the lossless decoding process is started, the flag extraction unit 311 of the control information extraction unit 301 determines whether or not the supplied encoded data is the first transmitted slice of the processing target flag group in step S461. Determine whether. When it is determined that the slice is the first transmitted slice of the processing target flag group, the process proceeds to step S462.

  In step S462, the flag extraction unit 311 extracts filter block flags for one flag group from the slice header of the processing target slice.

  When the filter block flag is extracted, the process proceeds to step S463. If it is determined in step S461 that the slice is not the first transmitted slice of the processing target flag group, the process proceeds to step S463.

  In step S463, the block size extraction unit 312 of the control information extraction unit 301 determines whether or not the supplied encoded data is the first transmitted slice of the processing target block size group. When it is determined that the slice is the first transmitted slice of the processing target block size group, the process proceeds to step S464.

  In step S464, the block size extraction unit 312 extracts a block size for one block size group from the slice header of the processing target slice.

  When the block size is extracted, the process proceeds to step S465. If it is determined in step S463 that the slice is not the first transmitted slice of the processing target block size group, the process proceeds to step S465.

  In step S465, the filter coefficient extracting unit 313 of the control information extracting unit 301 determines whether or not the supplied encoded data is the first transmitted slice of the processing target filter coefficient group. When it is determined that the slice is the first transmitted slice of the processing target filter coefficient group, the process proceeds to step S466.

  In step S466, the filter coefficient extraction unit 313 extracts filter coefficients for one filter coefficient group from the slice header of the processing target slice.

  When the filter coefficient is extracted, the process proceeds to step S467. If it is determined in step S465 that the slice is not the first transmitted slice of the processing target filter coefficient group, the process proceeds to step S467.

  In step S467, the decoding unit 222 decodes the processing target slice of the encoded data. In step S468, the decoded data holding unit 223 holds the decoded data obtained by decoding.

  In step S469, the decoded data holding unit 223 determines whether there is a slice from which all the elements of the control information (filter block flag, block size, and filter coefficient) have been extracted by the control information extraction unit 301. When it is determined that the extracted data is extracted, the decoded data holding unit 223 proceeds to step S470, and starts outputting the held decoded data to the inverse quantization unit 203 of the slice from which all the elements of the control information are extracted. To do.

  When the output of the decoded data is started, the process proceeds to step S471. If it is determined in step S469 that there is no slice from which all elements of the control information are extracted, the process proceeds to step S471.

  In step S471, the control information extraction unit 301 determines whether all slices in the frame have been processed. If it is determined that there is an unprocessed slice, the process returns to step S461, and the subsequent processing is repeated for the unprocessed slice. If it is determined in step S471 that all the slices in the frame have been processed, the lossless decoding process is terminated, the process returns to step S207 in FIG. 20, and the processes after step S208 are executed.

  By performing the lossless decoding process as described above, the lossless decoding unit 202 can extract each element of the control information added to the encoded data independently of each other and supply the extracted elements to the adaptive filter processing unit 207. Thereby, the adaptive filter process part 207 can perform an adaptive filter process appropriately. As a result, the adaptive filter processing unit 207 can reduce block distortion that cannot be removed by the deblocking filter and distortion due to quantization of the slice to be processed.

[Other examples]
Of course, in this case as well, each element such as the filter coefficient, the block size, and the filter block flag may be embedded in the slice header of the first slice of each group of elements, or in the slice header of another predetermined slice. It may be embedded.

  Further, the group of each element may be set for each GOP or each frame, for example, so that the number of groups of each element can be changed in the time direction.

<9. Ninth Embodiment>
[Description of QALF]
As shown in Non-Patent Document 3, the ALF block may have a quadtree structure. This technique is called QALF (Quad tree-based Adaptive Loop Filter). The quad tree structure is a hierarchical structure in which the area of one ALF block in the upper hierarchy in the lower hierarchy is divided into four.

  FIG. 42 shows an example in which ALF block division is expressed by a quadtree structure with a maximum number of layers of 3, and a filter block flag is designated for each ALF block.

  FIG. 42A shows layer 0, which is an ALF block that is the root of a quadtree structure. In the quad tree structure, each ALF block has a block partitioning flag indicating whether or not it is divided into four in the lower hierarchy. The value of the block partitioning flag of the ALF block shown in FIG. 42A is “1”. That is, this ALF block is divided into four in the lower hierarchy (layer 1). FIG. 42B shows the layer 1. That is, four ALF blocks are formed in layer 1.

  When the block partitioning flag is “0”, it is not divided into four in lower layers. That is, there is no further division, and a filter block flag is generated for the ALF block. That is, the ALF block whose block partitioning flag is “0” also has a filter block flag. “0” on the left of “0-1” shown in FIG. 42B indicates the block partitioning flag of the ALF block, and “1” on the right indicates the filter block flag of the ALF block.

  Two ALF blocks whose layer partitioning flag of layer 1 is “1” are further divided into four in a lower hierarchy (layer 2). FIG. 42C shows the layer 2. That is, 10 ALF blocks are formed in layer 2.

  Similarly, a filter block flag is also assigned to an ALF block whose block partitioning flag is “0” in layer 2. In FIG. 42C, the block partitioning flag of one ALF block is “1”. That is, the ALF block is divided into four in the lower hierarchy (layer 3). FIG. 42D shows the layer 3. That is, 13 ALF blocks are formed in layer 3.

  By forming a quad tree as shown in FIG. 42, the configuration of the ALF block finally becomes as shown in FIG. As described above, in the quadtree structure, the size of the ALF block is different for each hierarchy. That is, ALF blocks can have different sizes within a frame by adopting a quadtree structure.

  Control of the filter block flag in each ALF block is the same as in the case of the first embodiment. That is, the filter process is not performed on the area of the ALF block (the hatched portion in FIG. 43) where the value of the filter block flag is “0”.

  The problem that coding efficiency may be reduced in the case of multi-slice causes the same problem even in QALF with improved ALF block representation.

  FIG. 44 shows an example in which the area of slice 1 in FIG. 5 is encoded using the QALF technique. Here, the area of the bold line 421 indicates the area of slice 1. If the control information of the entire QALF 411 is divided into slices as shown by the thick line 421 to be a plurality of control information and added to the encoded data, information that overlaps between the control information is generated. End up.

  Therefore, also in the case of QALF, the image coding apparatus 100 includes control information for a plurality of slices in one slice header of the coded data by the same method as in the case of BALF described in the first embodiment. Like that. Similarly to the case of BALF, the image decoding apparatus 200 also extracts the control information and performs adaptive filter processing.

  By doing so, since the redundancy of the control information added to the encoded data is suppressed, the encoding efficiency can be improved as compared with the case where the control information is embedded for each slice.

<10. Tenth Embodiment>
[Personal computer]
The series of processes described above can be executed by hardware or can be executed by software. In this case, for example, a personal computer as shown in FIG. 45 may be configured.

  45, the CPU 501 of the personal computer 500 executes various processes according to a program stored in a ROM (Read Only Memory) 502 or a program loaded from a storage unit 513 to a RAM (Random Access Memory) 503. The RAM 503 also appropriately stores data necessary for the CPU 501 to execute various processes.

  The CPU 501, ROM 502, and RAM 503 are connected to each other via a bus 504. An input / output interface 510 is also connected to the bus 504.

  The input / output interface 510 includes an input unit 511 including a keyboard and a mouse, a display including a CRT (Cathode Ray Tube) and an LCD (Liquid Crystal Display), an output unit 512 including a speaker, and a hard disk. A communication unit 514 including a storage unit 513 and a modem is connected. The communication unit 514 performs communication processing via a network including the Internet.

  A drive 515 is connected to the input / output interface 510 as necessary, and a removable medium 521 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory is appropriately mounted, and a computer program read from them is It is installed in the storage unit 513 as necessary.

  When the above-described series of processing is executed by software, a program constituting the software is installed from a network or a recording medium.

  For example, as shown in FIG. 45, the recording medium is distributed to distribute the program to the user separately from the apparatus main body, and includes a magnetic disk (including a flexible disk) on which the program is recorded, an optical disk ( It only consists of removable media 521 consisting of CD-ROM (compact disc-read only memory), DVD (including digital versatile disc), magneto-optical disc (including MD (mini disc)), or semiconductor memory. Rather, it is composed of a ROM 502 on which a program is recorded and a hard disk included in the storage unit 513, which is distributed to the user in a state of being pre-installed in the apparatus main body.

  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.

  Further, in the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but may be performed in parallel or It also includes processes that are executed individually.

  Further, in this specification, the system represents the entire apparatus composed of a plurality of devices (apparatuses).

  In addition, in the above description, the configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units). Conversely, the configurations described above as a plurality of devices (or processing units) may be combined into a single device (or processing unit). Of course, a configuration other than that described above may be added to the configuration of each device (or each processing unit). Furthermore, if the configuration and operation of the entire system are substantially the same, a part of the configuration of a certain device (or processing unit) may be included in the configuration of another device (or other processing unit). . That is, the embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, the image encoding device 100 and the image decoding device 200 described above can be applied to any electronic device. Examples thereof will be described below.

<11. Eleventh embodiment>
[Television receiver]
FIG. 46 is a block diagram illustrating a main configuration example of a television receiver using the image decoding device 200 to which the present invention has been applied.

  The television receiver 1000 shown in FIG. 46 includes a terrestrial tuner 1013, a video decoder 1015, a video signal processing circuit 1018, a graphic generation circuit 1019, a panel drive circuit 1020, and a display panel 1021.

  The terrestrial tuner 1013 receives a broadcast wave signal of analog terrestrial broadcasting via an antenna, demodulates it, acquires a video signal, and supplies it to the video decoder 1015. The video decoder 1015 performs a decoding process on the video signal supplied from the terrestrial tuner 1013 and supplies the obtained digital component signal to the video signal processing circuit 1018.

  The video signal processing circuit 1018 performs predetermined processing such as noise removal on the video data supplied from the video decoder 1015 and supplies the obtained video data to the graphic generation circuit 1019.

  The graphic generation circuit 1019 generates video data of a program to be displayed on the display panel 1021, image data by processing based on an application supplied via a network, and the generated video data and image data to the panel drive circuit 1020. Supply. The graphic generation circuit 1019 generates video data (graphics) for displaying a screen used by the user for selecting an item and superimposing it on the video data of the program. A process of supplying data to the panel drive circuit 1020 is also appropriately performed.

  The panel drive circuit 1020 drives the display panel 1021 based on the data supplied from the graphic generation circuit 1019 and causes the display panel 1021 to display a program video and the various screens described above.

  The display panel 1021 includes an LCD (Liquid Crystal Display) or the like, and displays a program video or the like according to control by the panel drive circuit 1020.

  The television receiver 1000 also includes an audio A / D (Analog / Digital) conversion circuit 1014, an audio signal processing circuit 1022, an echo cancellation / audio synthesis circuit 1023, an audio amplification circuit 1024, and a speaker 1025.

  The terrestrial tuner 1013 acquires not only the video signal but also the audio signal by demodulating the received broadcast wave signal. The terrestrial tuner 1013 supplies the acquired audio signal to the audio A / D conversion circuit 1014.

  The audio A / D conversion circuit 1014 performs A / D conversion processing on the audio signal supplied from the terrestrial tuner 1013 and supplies the obtained digital audio signal to the audio signal processing circuit 1022.

  The audio signal processing circuit 1022 performs predetermined processing such as noise removal on the audio data supplied from the audio A / D conversion circuit 1014, and supplies the obtained audio data to the echo cancellation / audio synthesis circuit 1023.

  The echo cancellation / voice synthesis circuit 1023 supplies the voice data supplied from the voice signal processing circuit 1022 to the voice amplification circuit 1024.

  The audio amplifying circuit 1024 performs D / A conversion processing and amplification processing on the audio data supplied from the echo cancellation / audio synthesizing circuit 1023, adjusts to a predetermined volume, and then outputs the audio from the speaker 1025.

  Furthermore, the television receiver 1000 also includes a digital tuner 1016 and an MPEG decoder 1017.

  The digital tuner 1016 receives a broadcast wave signal of a digital broadcast (terrestrial digital broadcast, BS (Broadcasting Satellite) / CS (Communications Satellite) digital broadcast) via an antenna, demodulates, and MPEG-TS (Moving Picture Experts Group). -Transport Stream) and supply it to the MPEG decoder 1017.

  The MPEG decoder 1017 cancels the scramble applied to the MPEG-TS supplied from the digital tuner 1016, and extracts a stream including program data to be played back (viewing target). The MPEG decoder 1017 decodes the audio packet constituting the extracted stream, supplies the obtained audio data to the audio signal processing circuit 1022, decodes the video packet constituting the stream, and converts the obtained video data into the video This is supplied to the signal processing circuit 1018. Also, the MPEG decoder 1017 supplies EPG (Electronic Program Guide) data extracted from the MPEG-TS to the CPU 1032 via a path (not shown).

  The television receiver 1000 uses the above-described image decoding device 200 as the MPEG decoder 1017 for decoding video packets in this way. Note that MPEG-TS transmitted from a broadcasting station or the like is encoded by the image encoding device 100.

  As in the case of the image decoding device 200, the MPEG decoder 1017 extracts control information for a plurality of slices embedded in one slice header from the encoded data supplied from the image encoding device 100, and controls the control. Since adaptive filter processing is appropriately performed based on information, it is possible to suppress a reduction in encoding efficiency due to local control of filter processing.

  The video data supplied from the MPEG decoder 1017 is subjected to predetermined processing in the video signal processing circuit 1018 as in the case of the video data supplied from the video decoder 1015, and the generated video data in the graphic generation circuit 1019. Are appropriately superimposed and supplied to the display panel 1021 via the panel drive circuit 1020, and the image is displayed.

  The audio data supplied from the MPEG decoder 1017 is subjected to predetermined processing in the audio signal processing circuit 1022 as in the case of the audio data supplied from the audio A / D conversion circuit 1014, and an echo cancellation / audio synthesis circuit 1023. Are supplied to the audio amplifier circuit 1024 through which D / A conversion processing and amplification processing are performed. As a result, sound adjusted to a predetermined volume is output from the speaker 1025.

  The television receiver 1000 also includes a microphone 1026 and an A / D conversion circuit 1027.

  The A / D conversion circuit 1027 receives a user's voice signal captured by a microphone 1026 provided in the television receiver 1000 for voice conversation, and performs A / D conversion processing on the received voice signal. The obtained digital audio data is supplied to the echo cancellation / audio synthesis circuit 1023.

  When the audio data of the user (user A) of the television receiver 1000 is supplied from the A / D conversion circuit 1027, the echo cancellation / audio synthesis circuit 1023 performs echo cancellation on the audio data of the user A. The voice data obtained by combining with other voice data is output from the speaker 1025 via the voice amplifier circuit 1024.

  The television receiver 1000 further includes an audio codec 1028, an internal bus 1029, an SDRAM (Synchronous Dynamic Random Access Memory) 1030, a flash memory 1031, a CPU 1032, a USB (Universal Serial Bus) I / F 1033, and a network I / F 1034. .

  The A / D conversion circuit 1027 receives a user's voice signal captured by a microphone 1026 provided in the television receiver 1000 for voice conversation, and performs A / D conversion processing on the received voice signal. The obtained digital audio data is supplied to the audio codec 1028.

  The audio codec 1028 converts the audio data supplied from the A / D conversion circuit 1027 into data of a predetermined format for transmission via the network, and supplies the data to the network I / F 1034 via the internal bus 1029.

  The network I / F 1034 is connected to the network via a cable attached to the network terminal 1035. For example, the network I / F 1034 transmits the audio data supplied from the audio codec 1028 to another device connected to the network. In addition, the network I / F 1034 receives, for example, audio data transmitted from another device connected via the network via the network terminal 1035, and receives the audio data via the internal bus 1029 to the audio codec 1028. Supply.

  The audio codec 1028 converts the audio data supplied from the network I / F 1034 into data of a predetermined format, and supplies it to the echo cancellation / audio synthesis circuit 1023.

  The echo cancellation / speech synthesis circuit 1023 performs echo cancellation on the speech data supplied from the speech codec 1028, and synthesizes speech data obtained by combining with other speech data via the speech amplification circuit 1024. And output from the speaker 1025.

  The SDRAM 1030 stores various data necessary for the CPU 1032 to perform processing.

  The flash memory 1031 stores a program executed by the CPU 1032. The program stored in the flash memory 1031 is read by the CPU 1032 at a predetermined timing such as when the television receiver 1000 is activated. The flash memory 1031 also stores EPG data acquired via digital broadcasting, data acquired from a predetermined server via a network, and the like.

  For example, the flash memory 1031 stores MPEG-TS including content data acquired from a predetermined server via a network under the control of the CPU 1032. The flash memory 1031 supplies the MPEG-TS to the MPEG decoder 1017 via the internal bus 1029, for example, under the control of the CPU 1032.

  The MPEG decoder 1017 processes the MPEG-TS as in the case of the MPEG-TS supplied from the digital tuner 1016. In this way, the television receiver 1000 receives content data including video and audio via the network, decodes it using the MPEG decoder 1017, displays the video, and outputs audio. Can do.

  The television receiver 1000 also includes a light receiving unit 1037 that receives an infrared signal transmitted from the remote controller 1051.

  The light receiving unit 1037 receives infrared light from the remote controller 1051 and outputs a control code representing the content of the user operation obtained by demodulation to the CPU 1032.

  The CPU 1032 executes a program stored in the flash memory 1031 and controls the overall operation of the television receiver 1000 according to a control code supplied from the light receiving unit 1037. The CPU 1032 and each part of the television receiver 1000 are connected via a path (not shown).

  The USB I / F 1033 transmits and receives data to and from a device external to the television receiver 1000 connected via a USB cable attached to the USB terminal 1036. The network I / F 1034 is connected to the network via a cable attached to the network terminal 1035, and transmits / receives data other than audio data to / from various devices connected to the network.

  By using the image decoding apparatus 200 as the MPEG decoder 1017, the television receiver 1000 can extract control information for a plurality of slices added to one slice header of encoded data. Can be used to appropriately perform adaptive filter processing. As a result, the television receiver 1000 suppresses the reduction in the encoding efficiency for local control of the filter processing of the broadcast wave signal received via the antenna and the content data acquired via the network. Can be realized.

<12. Twelfth Embodiment>
[Mobile phone]
FIG. 48 is a block diagram illustrating a main configuration example of a mobile phone using the image encoding device and the image decoding device to which the present invention has been applied.

  A mobile phone 1100 shown in FIG. 48 includes a main control unit 1150, a power supply circuit unit 1151, an operation input control unit 1152, an image encoder 1153, a camera I / F unit 1154, an LCD control, which are configured to control each unit in an integrated manner. Section 1155, image decoder 1156, demultiplexing section 1157, recording / reproducing section 1162, modulation / demodulation circuit section 1158, and audio codec 1159. These are connected to each other via a bus 1160.

  The mobile phone 1100 includes an operation key 1119, a CCD (Charge Coupled Devices) camera 1116, a liquid crystal display 1118, a storage unit 1123, a transmission / reception circuit unit 1163, an antenna 1114, a microphone (microphone) 1121, and a speaker 1117.

  When the end call and the power key are turned on by the user's operation, the power supply circuit unit 1151 starts up the mobile phone 1100 in an operable state by supplying power from the battery pack to each unit.

  The mobile phone 1100 transmits and receives voice signals, e-mails and image data, and images in various modes such as a voice call mode and a data communication mode based on the control of the main control unit 1150 including a CPU, a ROM, a RAM, and the like. Various operations such as shooting or data recording are performed.

  For example, in the voice call mode, the mobile phone 1100 converts the voice signal collected by the microphone (microphone) 1121 into digital voice data by the voice codec 1159, performs spectrum spread processing by the modulation / demodulation circuit unit 1158, and transmits and receives The unit 1163 performs digital / analog conversion processing and frequency conversion processing. The cellular phone 1100 transmits the transmission signal obtained by the conversion process to a base station (not shown) via the antenna 1114. The transmission signal (voice signal) transmitted to the base station is supplied to the mobile phone of the other party via the public telephone line network.

  Further, for example, in the voice call mode, the cellular phone 1100 amplifies the received signal received by the antenna 1114 by the transmission / reception circuit unit 1163, further performs frequency conversion processing and analog-digital conversion processing, and the modulation / demodulation circuit unit 1158 performs spectrum despreading processing Then, the audio codec 1159 converts it into an analog audio signal. The cellular phone 1100 outputs an analog audio signal obtained by the conversion from the speaker 1117.

  Further, for example, when transmitting an e-mail in the data communication mode, the mobile phone 1100 receives e-mail text data input by operating the operation key 1119 in the operation input control unit 1152. The cellular phone 1100 processes the text data in the main control unit 1150 and displays it on the liquid crystal display 1118 as an image via the LCD control unit 1155.

  In addition, the mobile phone 1100 generates e-mail data in the main control unit 1150 based on text data received by the operation input control unit 1152, user instructions, and the like. The cellular phone 1100 performs spread spectrum processing on the e-mail data by the modulation / demodulation circuit unit 1158 and digital / analog conversion processing and frequency conversion processing by the transmission / reception circuit unit 1163. The cellular phone 1100 transmits the transmission signal obtained by the conversion process to a base station (not shown) via the antenna 1114. The transmission signal (e-mail) transmitted to the base station is supplied to a predetermined destination via a network and a mail server.

  Further, for example, when receiving an e-mail in the data communication mode, the mobile phone 1100 receives and amplifies the signal transmitted from the base station by the transmission / reception circuit unit 1163 via the antenna 1114, and further performs frequency conversion processing and Analog-digital conversion processing. The cellular phone 1100 performs spectrum despreading processing on the received signal by the modulation / demodulation circuit unit 1158 to restore the original e-mail data. The cellular phone 1100 displays the restored e-mail data on the liquid crystal display 1118 via the LCD control unit 1155.

  Note that the mobile phone 1100 can also record (store) the received e-mail data in the storage unit 1123 via the recording / playback unit 1162.

  The storage unit 1123 is an arbitrary rewritable storage medium. The storage unit 1123 may be, for example, a semiconductor memory such as a RAM or a built-in flash memory, a hard disk, or a removable disk such as a magnetic disk, a magneto-optical disk, an optical disk, a USB memory, or a memory card. It may be media. Of course, other than these may be used.

  Furthermore, for example, when transmitting image data in the data communication mode, the mobile phone 1100 generates image data with the CCD camera 1116 by imaging. The CCD camera 1116 has an optical device such as a lens and a diaphragm and a CCD as a photoelectric conversion element, images a subject, converts the intensity of received light into an electrical signal, and generates image data of the subject image. The CCD camera 1116 encodes the image data by the image encoder 1153 via the camera I / F unit 1154 and converts the encoded image data into encoded image data.

  The cellular phone 1100 uses the above-described image encoding device 100 as the image encoder 1153 that performs such processing. Therefore, the image encoder 1053 can suppress a reduction in encoding efficiency due to local control of filter processing, as in the case of the image encoding device 100. For example, since the image encoder 1053 adds control information for a plurality of slices added to one slice header of the encoded data, the encoding efficiency can be improved as compared with the case where the control information is embedded for each slice.

  At the same time, the cellular phone 1100 converts the sound collected by the microphone (microphone) 1121 during imaging by the CCD camera 1116 from analog to digital at the audio codec 1159 and further encodes it.

  The cellular phone 1100 multiplexes the encoded image data supplied from the image encoder 1153 and the digital audio data supplied from the audio codec 1159 in a demultiplexing unit 1157 using a predetermined method. The cellular phone 1100 performs spread spectrum processing on the multiplexed data obtained as a result by the modulation / demodulation circuit unit 1158 and digital / analog conversion processing and frequency conversion processing by the transmission / reception circuit unit 1163. The cellular phone 1100 transmits the transmission signal obtained by the conversion process to a base station (not shown) via the antenna 1114. A transmission signal (image data) transmitted to the base station is supplied to a communication partner via a network or the like.

  When image data is not transmitted, the mobile phone 1100 can also display the image data generated by the CCD camera 1116 on the liquid crystal display 1118 via the LCD control unit 1155 without using the image encoder 1153.

  Further, for example, when receiving data of a moving image file linked to a simple homepage or the like in the data communication mode, the mobile phone 1100 transmits a signal transmitted from the base station to the transmission / reception circuit unit 1163 via the antenna 1114. Receive, amplify, and further perform frequency conversion processing and analog-digital conversion processing. The cellular phone 1100 restores the original multiplexed data by subjecting the received signal to spectrum despreading processing by the modulation / demodulation circuit unit 1158. In the cellular phone 1100, the demultiplexing unit 1157 separates the multiplexed data and divides it into encoded image data and audio data.

  The cellular phone 1100 generates reproduced moving image data by decoding the encoded image data in the image decoder 1156, and displays it on the liquid crystal display 1118 via the LCD control unit 1155. Thereby, for example, the moving image data included in the moving image file linked to the simple homepage is displayed on the liquid crystal display 1118.

  The cellular phone 1100 uses the above-described image decoding device 200 as the image decoder 1156 that performs such processing. Therefore, the image decoder 1156 can extract control information for a plurality of slices added to one slice header of the encoded data, as in the case of the image decoding device 200, and further using the control information. Appropriate adaptive filtering can be performed. As a result, it is possible to realize suppression of reduction in encoding efficiency for local control of filter processing.

  At this time, the cellular phone 1100 simultaneously converts digital audio data into an analog audio signal in the audio codec 1159 and outputs the analog audio signal from the speaker 1117. Thereby, for example, audio data included in the moving image file linked to the simple homepage is reproduced.

  As in the case of e-mail, the mobile phone 1100 can record (store) the data linked to the received simplified home page in the storage unit 1123 via the recording / playback unit 1162. .

  Further, the mobile phone 1100 can analyze the two-dimensional code captured by the CCD camera 1116 and acquire information recorded in the two-dimensional code in the main control unit 1150.

  Further, the cellular phone 1100 can communicate with an external device by infrared rays at the infrared communication unit 1181.

  The cellular phone 1100 uses the image encoding device 100 as the image encoder 1153, and for example, encodes encoded data generated by encoding image data generated by the CCD camera 1116 by local control of filter processing. Reduction in efficiency can be suppressed. As a result, the mobile phone 1100 can provide encoded data (image data) with higher encoding efficiency to other devices than when control information is embedded for each slice.

  Further, by using the image decoding apparatus 200 as the image decoder 1156, the mobile phone 1100 can extract control information for a plurality of slices added to one slice header of the encoded data, and further, the control information Can be used to appropriately perform adaptive filter processing. As a result, the mobile phone 1100 can realize, for example, suppression of a reduction in encoding efficiency for local control of filter processing of data of a moving image file linked to a simple homepage or the like.

  In the above description, the mobile phone 1100 is described as using the CCD camera 1116. However, instead of the CCD camera 1116, an image sensor (CMOS image sensor) using a CMOS (Complementary Metal Oxide Semiconductor) is used. May be. Also in this case, the mobile phone 1100 can capture an image of a subject and generate image data of the image of the subject, as in the case where the CCD camera 1116 is used.

  In the above description, the cellular phone 1100 has been described. For example, an imaging function similar to that of the cellular phone 1100 such as a PDA (Personal Digital Assistants), a smartphone, an UMPC (Ultra Mobile Personal Computer), a netbook, a notebook personal computer, or the like. As long as it is a device having a communication function, the image encoding device 100 and the image decoding device 200 can be applied to any device as in the case of the mobile phone 1100.

<13. Thirteenth Embodiment>
[Hard Disk Recorder]
FIG. 48 is a block diagram showing a main configuration example of a hard disk recorder using an image encoding device and an image decoding device to which the present invention is applied.

  A hard disk recorder (HDD recorder) 1200 shown in FIG. 48 receives audio data and video data of a broadcast program included in a broadcast wave signal (television signal) transmitted from a satellite or a ground antenna received by a tuner. This is an apparatus for storing in a built-in hard disk and providing the stored data to the user at a timing according to the user's instruction.

  The hard disk recorder 1200 can extract, for example, audio data and video data from broadcast wave signals, appropriately decode them, and store them in a built-in hard disk. The hard disk recorder 1200 can also acquire audio data and video data from other devices via a network, for example, decode them as appropriate, and store them in a built-in hard disk.

  Further, the hard disk recorder 1200, for example, decodes audio data and video data recorded on the built-in hard disk, supplies them to the monitor 1260, displays the image on the screen of the monitor 1260, and displays the sound from the speaker of the monitor 1260. Can be output. Further, the hard disk recorder 1200 decodes audio data and video data extracted from a broadcast wave signal acquired via a tuner, or audio data and video data acquired from another device via a network, for example. The image can be supplied to the monitor 1260, the image can be displayed on the screen of the monitor 1260, and the sound can be output from the speaker of the monitor 1260.

  Of course, other operations are possible.

  As shown in FIG. 48, the hard disk recorder 1200 includes a receiving unit 1221, a demodulating unit 1222, a demultiplexer 1223, an audio decoder 1224, a video decoder 1225, and a recorder control unit 1226. The hard disk recorder 1200 further includes an EPG data memory 1227, a program memory 1228, a work memory 1229, a display converter 1230, an OSD (On Screen Display) control unit 1231, a display control unit 1232, a recording / playback unit 1233, a D / A converter 1234, And a communication unit 1235.

  In addition, the display converter 1230 includes a video encoder 1241. The recording / playback unit 1233 includes an encoder 1251 and a decoder 1252.

  The receiving unit 1221 receives an infrared signal from a remote controller (not shown), converts it into an electrical signal, and outputs it to the recorder control unit 1226. The recorder control unit 1226 is constituted by, for example, a microprocessor and executes various processes according to a program stored in the program memory 1228. At this time, the recorder control unit 1226 uses the work memory 1229 as necessary.

  The communication unit 1235 is connected to a network and performs communication processing with other devices via the network. For example, the communication unit 1235 is controlled by the recorder control unit 1226, communicates with a tuner (not shown), and mainly outputs a channel selection control signal to the tuner.

  The demodulator 1222 demodulates the signal supplied from the tuner and outputs the demodulated signal to the demultiplexer 1223. The demultiplexer 1223 separates the data supplied from the demodulation unit 1222 into audio data, video data, and EPG data, and outputs them to the audio decoder 1224, the video decoder 1225, or the recorder control unit 1226, respectively.

  The audio decoder 1224 decodes the input audio data and outputs it to the recording / playback unit 1233. The video decoder 1225 decodes the input video data and outputs it to the display converter 1230. The recorder control unit 1226 supplies the input EPG data to the EPG data memory 1227 for storage.

  The display converter 1230 encodes the video data supplied from the video decoder 1225 or the recorder control unit 1226 into, for example, NTSC (National Television Standards Committee) video data by the video encoder 1241 and outputs the encoded video data to the recording / reproducing unit 1233. The display converter 1230 converts the screen size of the video data supplied from the video decoder 1225 or the recorder control unit 1226 into a size corresponding to the size of the monitor 1260, and converts the video data to NTSC video data by the video encoder 1241. Then, it is converted into an analog signal and output to the display control unit 1232.

  The display control unit 1232 superimposes the OSD signal output from the OSD (On Screen Display) control unit 1231 on the video signal input from the display converter 1230 under the control of the recorder control unit 1226, and displays it on the monitor 1260 display. Output and display.

  The monitor 1260 is also supplied with the audio data output from the audio decoder 1224 after being converted into an analog signal by the D / A converter 1234. The monitor 1260 outputs this audio signal from a built-in speaker.

  The recording / playback unit 1233 includes a hard disk as a storage medium for recording video data, audio data, and the like.

  For example, the recording / reproducing unit 1233 encodes the audio data supplied from the audio decoder 1224 by the encoder 1251. The recording / playback unit 1233 encodes the video data supplied from the video encoder 1241 of the display converter 1230 by the encoder 1251. The recording / playback unit 1233 combines the encoded data of the audio data and the encoded data of the video data by a multiplexer. The recording / playback unit 1233 amplifies the synthesized data by channel coding, and writes the data to the hard disk via the recording head.

  The recording / playback unit 1233 plays back the data recorded on the hard disk via the playback head, amplifies it, and separates it into audio data and video data by a demultiplexer. The recording / playback unit 1233 uses the decoder 1252 to decode the audio data and the video data. The recording / playback unit 1233 performs D / A conversion on the decoded audio data and outputs it to the speaker of the monitor 1260. In addition, the recording / playback unit 1233 performs D / A conversion on the decoded video data and outputs it to the display of the monitor 1260.

  The recorder control unit 1226 reads the latest EPG data from the EPG data memory 1227 based on the user instruction indicated by the infrared signal from the remote controller received via the receiving unit 1221, and supplies it to the OSD control unit 1231. To do. The OSD control unit 1231 generates image data corresponding to the input EPG data, and outputs the image data to the display control unit 1232. The display control unit 1232 outputs the video data input from the OSD control unit 1231 to the display of the monitor 1260 for display. As a result, an EPG (electronic program guide) is displayed on the display of the monitor 1260.

  Also, the hard disk recorder 1200 can acquire various data such as video data, audio data, or EPG data supplied from another device via a network such as the Internet.

  The communication unit 1235 is controlled by the recorder control unit 1226, acquires encoded data such as video data, audio data, and EPG data transmitted from another device via the network, and supplies the encoded data to the recorder control unit 1226. To do. For example, the recorder control unit 1226 supplies the encoded data of the acquired video data and audio data to the recording / playback unit 1233 and stores it in the hard disk. At this time, the recorder control unit 1226 and the recording / playback unit 1233 may perform processing such as re-encoding as necessary.

  Also, the recorder control unit 1226 decodes the acquired encoded data of video data and audio data, and supplies the obtained video data to the display converter 1230. Similar to the video data supplied from the video decoder 1225, the display converter 1230 processes the video data supplied from the recorder control unit 1226, supplies the processed video data to the monitor 1260 via the display control unit 1232, and displays the image. .

  In accordance with the image display, the recorder control unit 1226 may supply the decoded audio data to the monitor 1260 via the D / A converter 1234 and output the sound from the speaker.

  Further, the recorder control unit 1226 decodes the encoded data of the acquired EPG data, and supplies the decoded EPG data to the EPG data memory 1227.

  The hard disk recorder 1200 as described above uses the image decoding device 200 as a decoder incorporated in the video decoder 1225, the decoder 1252, and the recorder control unit 1226. Therefore, the decoder incorporated in the video decoder 1225, the decoder 1252, and the recorder control unit 1226 receives control information for a plurality of slices added to one slice header of the encoded data, as in the case of the image decoding device 200. In addition, the adaptive filter processing can be appropriately performed using the control information. As a result, it is possible to realize suppression of reduction in encoding efficiency for local control of filter processing.

  Therefore, the hard disk recorder 1200 can extract the control information for a plurality of slices added to one slice header of the encoded data, and can appropriately execute the adaptive filter processing using the control information. it can. As a result, the hard disk recorder 1200 is used for local control of filter processing of, for example, video data received via the tuner or the communication unit 1235 or video data recorded on the hard disk of the recording / playback unit 1233. Suppression of reduction in encoding efficiency can be realized.

  The hard disk recorder 1200 uses the image encoding device 100 as the encoder 1251. Therefore, the encoder 1251 can suppress a reduction in encoding efficiency due to local control of filter processing, as in the case of the image encoding device 100. For example, since the encoder 1251 adds control information for a plurality of slices added to one slice header of the encoded data, the encoding efficiency can be improved as compared with the case where the control information is embedded for each slice.

  Therefore, the hard disk recorder 1200 can suppress a reduction in encoding efficiency due to local control of filter processing of encoded data to be recorded in the hard disk, for example, by using the image encoding device 100 as the encoder 1251. As a result, the hard disk recorder 1200 can use the storage area of the hard disk more efficiently than when the control information is embedded for each slice.

  In the above description, the hard disk recorder 1200 for recording video data and audio data on the hard disk has been described. Of course, any recording medium may be used. For example, even in a recorder to which a recording medium other than a hard disk such as a flash memory, an optical disk, or a video tape is applied, the image encoding device 100 and the image decoding device 200 are applied as in the case of the hard disk recorder 1200 described above. Can do.

<14. Fourteenth Embodiment>
[camera]
FIG. 49 is a block diagram illustrating a main configuration example of a camera using an image encoding device and an image decoding device to which the present invention has been applied.

  The camera 1300 shown in FIG. 49 images a subject and displays an image of the subject on the LCD 1316 or records it on the recording medium 1333 as image data.

  The lens block 1311 causes light (that is, an image of the subject) to enter the CCD / CMOS 1312. The CCD / CMOS 1312 is an image sensor using CCD or CMOS, converts the intensity of received light into an electric signal, and supplies it to the camera signal processing unit 1313.

  The camera signal processing unit 1313 converts the electrical signal supplied from the CCD / CMOS 1312 into Y, Cr, and Cb color difference signals, and supplies them to the image signal processing unit 1314. The image signal processing unit 1314 performs predetermined image processing on the image signal supplied from the camera signal processing unit 1313 or encodes the image signal with the encoder 1341 under the control of the controller 1321. The image signal processing unit 1314 supplies encoded data generated by encoding the image signal to the decoder 1315. Further, the image signal processing unit 1314 acquires display data generated in the on-screen display (OSD) 1320 and supplies it to the decoder 1315.

  In the above processing, the camera signal processing unit 1313 appropriately uses a DRAM (Dynamic Random Access Memory) 1318 connected via the bus 1317, and image data or a code obtained by encoding the image data as necessary. The digitized data or the like is held in the DRAM 1318.

  The decoder 1315 decodes the encoded data supplied from the image signal processing unit 1314 and supplies the obtained image data (decoded image data) to the LCD 1316. In addition, the decoder 1315 supplies the display data supplied from the image signal processing unit 1314 to the LCD 1316. The LCD 1316 appropriately combines the image of the decoded image data supplied from the decoder 1315 and the image of the display data, and displays the combined image.

  Under the control of the controller 1321, the on-screen display 1320 outputs display data such as menu screens and icons composed of symbols, characters, or graphics to the image signal processing unit 1314 via the bus 1317.

  The controller 1321 executes various processes based on a signal indicating the content instructed by the user using the operation unit 1322, and also via the bus 1317, an image signal processing unit 1314, a DRAM 1318, an external interface 1319, an on-screen display. 1320, media drive 1323, and the like are controlled. The FLASH ROM 1324 stores programs and data necessary for the controller 1321 to execute various processes.

  For example, the controller 1321 can encode the image data stored in the DRAM 1318 or decode the encoded data stored in the DRAM 1318 instead of the image signal processing unit 1314 and the decoder 1315. At this time, the controller 1321 may be configured to perform encoding / decoding processing by a method similar to the encoding / decoding method of the image signal processing unit 1314 or the decoder 1315, or the image signal processing unit 1314 or the decoder 1315 is compatible. The encoding / decoding process may be performed by a method that is not performed.

  For example, when the start of image printing is instructed from the operation unit 1322, the controller 1321 reads out image data from the DRAM 1318 and supplies it to the printer 1334 connected to the external interface 1319 via the bus 1317. Let it print.

  Further, for example, when image recording is instructed from the operation unit 1322, the controller 1321 reads the encoded data from the DRAM 1318 and supplies it to the recording medium 1333 mounted on the media drive 1323 via the bus 1317. Remember.

  The recording medium 1333 is an arbitrary readable / writable removable medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory. Of course, the recording medium 1333 may be of any kind as a removable medium, and may be a tape device, a disk, or a memory card. Of course, a non-contact IC card or the like may be used.

  Further, the media drive 1323 and the recording medium 1333 may be integrated and configured by a non-portable storage medium such as a built-in hard disk drive or SSD (Solid State Drive).

  The external interface 1319 is composed of, for example, a USB input / output terminal, and is connected to the printer 1334 when printing an image. In addition, a drive 1331 is connected to the external interface 1319 as necessary, and a removable medium 1332 such as a magnetic disk, an optical disk, or a magneto-optical disk is appropriately mounted, and a computer program read from them is loaded as necessary. Installed in the FLASH ROM 1324.

  Furthermore, the external interface 1319 has a network interface connected to a predetermined network such as a LAN or the Internet. For example, the controller 1321 can read the encoded data from the DRAM 1318 in accordance with an instruction from the operation unit 1322 and supply the encoded data to the other device connected via the network from the external interface 1319. In addition, the controller 1321 acquires encoded data and image data supplied from another device via the network via the external interface 1319, holds the data in the DRAM 1318, or supplies it to the image signal processing unit 1314. Can be.

  The camera 1300 as described above uses the image decoding device 200 as the decoder 1315. Therefore, the decoder 1315 can extract control information for a plurality of slices added to one slice header of encoded data, as in the case of the image decoding apparatus 200, and further, using the control information, Adaptive filtering can be performed. As a result, it is possible to realize suppression of reduction in encoding efficiency for local control of filter processing.

  Therefore, the camera 1300 can extract control information for a plurality of slices added to one slice header of the encoded data, and can appropriately execute adaptive filter processing using the control information. . As a result, the camera 1300 can, for example, store image data generated in the CCD / CMOS 1312, encoded data of video data read from the DRAM 1318 or the recording medium 1333, or encoded data of video data acquired via a network. Thus, it is possible to realize suppression of reduction in encoding efficiency for local control of filter processing.

  The camera 1300 uses the image encoding device 100 as the encoder 1341. Therefore, the encoder 1341 can suppress a reduction in encoding efficiency due to local control of filter processing, as in the case of the image encoding device 100. For example, since control information for a plurality of slices added to one slice header of encoded data is added, encoding efficiency can be improved as compared with the case where control information is embedded for each slice.

  Therefore, for example, the camera 1300 can suppress a reduction in encoding efficiency due to local control of filter processing of encoded data recorded in the DRAM 1318 or the recording medium 1333 or encoded data provided to another device. it can. As a result, the camera 1300 can use the storage area of the DRAM 1318 or the recording medium 1333 more efficiently. The camera 1300 can also provide encoded data (image data) with high encoding efficiency to other devices.

  Note that the decoding method of the image decoding device 200 may be applied to the decoding process performed by the controller 1321. Similarly, the encoding method of the image encoding device 100 may be applied to the encoding process performed by the controller 1321.

  The image data captured by the camera 1300 may be a moving image or a still image.

  Of course, the image encoding device 100 and the image decoding device 200 can also be applied to devices and systems other than the devices described above.

  The size of the macroblock is not limited to 16 × 16 pixels. For example, the present invention can be applied to macroblocks of any size such as 32 × 32 pixels shown in FIG.

  In the above description, the flag information or the like is described as being multiplexed (description) into the bitstream, but in addition to multiplexing, for example, a flag and image data (or bitstream) may be transmitted (recorded). Good. There may be a form in which the flag and the image data (or bit stream) are connected (added).

  Concatenation (addition) indicates a state in which image data (or bit stream) and a flag are linked to each other (a state in which correspondence is established), and the physical positional relationship is arbitrary. For example, the image data (or bit stream) and the flag may be transmitted through different transmission paths. Further, the image data (or bit stream) and the flag may be recorded on different recording media (or different recording areas in the same recording medium). Note that the unit for linking the image data (or bit stream) and the flag is arbitrary, and may be set, for example, in encoding processing units (one frame, multiple frames, etc.).

  DESCRIPTION OF SYMBOLS 100 Image coding apparatus, 112 Control information generation part, 113 Adaptive filter process part, 132 Block information generation part, 141 Processing object slice area | region identification part, 142 ALF block setting part, 143 Processing object ALF block area | region identification part, 144 Determination part , 145 filter block flag generation unit, 171 control unit, 172 adaptive filter, 173 selection unit, 181 encoding unit, 182 encoded data holding unit, 183 control information holding unit, 184 control information adding unit, 200 image decoding device, 202 Lossless decoding unit, 207 adaptive filter processing unit, 221 control information extraction unit, 222 decoding unit, 223 decoded data holding unit, 251 control unit, 261 header analysis unit, 281 control information addition unit, 291 flag addition unit, 292 with block size Addition unit, 293 filter coefficient addition unit, 301 control information extraction unit, 311 flag extraction unit, 312 block size extraction unit, 313 filter coefficient extraction unit

Claims (11)

Encoding to generate a bitstream that encodes an image and includes filter control information that controls filter processing in units of slices, corresponding to the plurality of slices, as header information of a specific slice of the plurality of slices of the image An image processing apparatus comprising the unit. The image processing device according to claim 1, wherein the encoding unit includes the filter control information in header information of the slice transmitted at the beginning of a frame. The image processing apparatus according to claim 1, wherein the encoding unit includes the filter control information in header information of the slice located at a head of a frame. The image processing apparatus according to claim 1, further comprising: a filter unit that performs the filter process on the image according to the filter control information. A deblock filter processing unit that performs a deblock filter process on the image;
The filter unit, the image processing apparatus according to claim 4 configured to perform the filtering process with respect to the said de-blocking filter processing by the deblocking filter processing unit is performed the image. Image processing that encodes an image and generates a bitstream that includes filter control information that controls filter processing in units of slices, corresponding to the plurality of slices, as header information of a specific slice of the plurality of slices of the image Method. The image processing method according to claim 6, wherein the filter control information is included in header information of the slice transmitted at the beginning of a frame. The image processing method according to claim 6, wherein the filter control information is included in header information of the slice located at a head of a frame. The image processing method according to claim 6, wherein the filtering process is performed on the image according to the filter control information. Perform deblocking filter processing on the image,
The image processing method according to claim 6, wherein the filter processing is performed on the image on which the deblocking filter processing has been performed. Computer
Encoding to generate a bitstream that encodes an image and includes filter control information that controls filter processing in units of slices, corresponding to the plurality of slices, as header information of a specific slice of the plurality of slices of the image A program that functions as a part.

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