Title of the invention: video coding or video decoding apparatus, video coding or video decoding method, program, and recording medium.
Technical field
[0001]
　The present invention relates to a video coding or video decoding apparatus, a video coding or video decoding method, a program for video coding or video decoding processing, and a recording medium.
Background technology
[0002]
　In the in-screen prediction coding, the in-screen prediction image is generated from the reconstructed image adjacent to the processing target block. For example, in the HEVC (High Efficiency Video Coding) standard described in Non-Patent Document 1, a reconstructed image corresponding to one pixel adjacent to the left side and one pixel adjacent to the upward direction with respect to the processing target block is displayed. By setting it in the reference range, an in-screen predicted image is generated.
Prior art literature
Non-patent literature
[0003]
Non-Patent Document 1: R. Joshi et al., "High Efficiency Video Coding (HEVC) Screen Content Coding: Draft 5" document JCTVC-V1005, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29/WG 11, 22nd Meeting: Geneva, CH, 15-21 Oct. 2015.
Outline of the invention
Problems to be solved by the invention
[0004]
　However, when the range of use of the image used for the in-screen prediction is expanded, there is a problem that the size requirement of the line buffer used in the video coding device and the video decoding device increases according to the expanded range. Therefore, it is desired to adaptively control the range of use of the image used for in-screen prediction.
[0005]
　An object of the present invention is to provide a video coding or video decoding device, a video coding or video decoding method, a program, and a recording medium that enable adaptive control of the range of use of an image used for in-screen prediction. To provide.
Means to solve problems
[0006]
　According to one aspect of the present invention, the video coding or video decoding apparatus determines the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. Based on this, a control that controls a partial range used for the in-screen prediction to be equal to or less than a predetermined maximum range across the end of the unit in the use range of the image used for the in-screen prediction in a predetermined direction. It has a part.
[0007]
　According to one aspect of the present invention, the video coding or video decoding method determines the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. Based on this, the partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined maximum range across the end of the unit in the use range of the image used for the in-screen prediction in a predetermined direction. ,including.
[0008]
　According to one aspect of the present invention, the program is based on the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. Video coding including controlling a partial range used for the in-screen prediction to be less than or equal to a predetermined maximum range across the end of the unit in a predetermined direction in the range of use of the image used for the prediction. Alternatively, it is a program for causing a computer to execute a video decoding process.
[0009]
　According to one aspect of the present invention, the recording medium is based on the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. A video code including controlling a partial range used for the in-screen prediction to be equal to or less than a predetermined maximum range across the end of the unit in a predetermined direction in the use range of the image used for the in-screen prediction. It is a non-temporary recording medium that can be read by a computer on which a program for causing a computer to perform conversion or video decoding processing is recorded.
Effect of the invention
[0010]
　According to one aspect of the present invention, it is possible to adaptively control the range of use of the image used for in-screen prediction. In addition, according to the present invention, other effects may be produced in place of or in combination with the effect.
A brief description of the drawing
[0011]
[Fig. 1] Fig. 1 shows a specific example of a reconstructed image used for in-screen prediction in the above-mentioned HEVC standard for a processing target block composed of 4 horizontal pixels bw and 4 vertical pixels Bh. It is a figure which shows.
FIG. 2 is a diagram showing a specific example of an enlarged reference range for a processing target block composed of 4 horizontal pixels bw and 4 vertical pixels Bh.
FIG. 3 is an explanatory diagram showing an example of a schematic configuration of an in-screen prediction device 100 according to an embodiment of the present invention.
FIG. 4 is a block diagram showing an example of a schematic configuration of the area control processing unit 110 according to the first embodiment.
FIG. 5 is a diagram for explaining a specific example of processing related to the area control processing unit 110.
FIG. 6 is a flowchart for explaining an example of a processing flow performed by the in-screen prediction device 100.
FIG. 7 is a diagram for explaining the effect according to the embodiment of the first embodiment.
FIG. 8 is a block diagram showing a schematic configuration of a video coding device 800.
FIG. 9 is a block diagram showing a schematic configuration of a video decoding device 900.
FIG. 10 is a block diagram showing a schematic configuration of an information processing system 100 to which the in-screen prediction device 100 is applied.
FIG. 11 is a diagram showing a system in which the above-mentioned video coding device 800 and the above-mentioned video decoding device 900 are connected by a transmission line 300 such as a wireless transmission line or a wired transmission line.
FIG. 12 is a block diagram showing an example of a schematic configuration of the video coding apparatus 800 according to the second embodiment.
FIG. 13 is a block diagram showing an example of a schematic configuration of the video decoding apparatus 900 according to the second embodiment.
Mode for carrying out the invention
[0012]
　Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, elements that can be similarly described may be designated by the same reference numerals so that duplicate description may be omitted.
[0013]
　The explanation is given in the following order.
　1. 1. Related technology
　2. Outline of the embodiment
　3. First Embodiment
　　3.1. Configuration of in-screen prediction device 100
　　3.2. Technical features
　　3.3. Specific example
　　3.4. Application example
　　3.5. Modification example
　4. Second Embodiment
　　4.1. Configuration
　　4.2. Technical features
　5. Other forms
[0014]
　<< 1. Related Techniques >> As
　a technique related to the embodiment of the present invention, in-screen prediction performed in the video coding process and the video decoding process will be described.
[0015]
　As described in Reference 1 below, for example, in the in-screen prediction coding of the HEVC (High Efficiency Video Coding) standard, the in-screen prediction image is generated from the reconstructed image adjacent to the processing target block.
　Reference 1: R. Joshi et al., "High Efficiency Video Coding (HEVC) Screen Content Coding: Draft 5" document JCTVC-V1005, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29/WG 11, 22nd Meeting: Geneva, CH, 15-21 Oct. 2015.
[0016]
　FIG. 1 is a diagram showing a specific example of a reconstructed image used for in-screen prediction in the above-mentioned HEVC standard for a processing target block composed of 4 horizontal pixels bw and 4 vertical pixels Bh. .. Further, as shown in FIG. 1, the reference range of the reconstructed image referred to for in-screen prediction is 1 pixel in the left Klepht and 1 pixel in the upward Kup.
[0017]
　Further, in References 2 and 3 below, it is proposed to expand the reference range used for the in-screen prediction in order to improve the prediction efficiency of the in-screen prediction.
　Reference 2: J. Pfaff et al., "Intra prediction modes based on neural networks", JVET-J0037, Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29/ WG 11 10th Meeting: San Diego, US, 10-20 Apr. 2018.
　Reference 3: P. Lin et al., "Multiple reference line intra prediction based on JEM7.0", JVET-J0070, Joint Video Experts Team ( JVET) of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29/WG 11 10th Meeting: San Diego, US, 10-20 Apr. 2018.
[0018]
　For example, FIG. 2 is a diagram showing a specific example of an enlarged reference range for a processing target block composed of four horizontal pixels bw and four vertical pixels Bh. As shown in FIG. 2, the reference range for referring to the reconstructed image is 4 pixels in the left Klepht and 4 pixels in the upward Kup.
[0019]
　<< 2. Outline of Embodiment >>
　First, the outline of the embodiment of the present invention will be described.
[0020]
　(1) Technical Issues
　As described above, when the usage range (reference range) of the image used for in-screen prediction is expanded, the problem that the size requirement of the line buffer used in the video coding device and the video decoding device increases. There is.
[0021]
　Specifically, when the number of horizontal pixels of the picture to be encoded is w pixels, the pixel bit accuracy is bitDeptth bits, and the upward range Kup of the reference image used for in-screen prediction is expanded from 1 pixel to 4 pixels. The line buffer size request increases from w * bitDeptth bits to w * bitDepts * 4 bits. Therefore, it is desired to adaptively control the range of use of the image used for in-screen prediction.
[0022]
　Therefore, an object of the present embodiment is to adaptively control the range of use of the image used for in-plane prediction.
[0023]
　(2) Technical Features In the
　embodiment which is one aspect of the present invention, for example, the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. Based on this, the partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined maximum range across the end of the unit in the use range of the image used for the in-screen prediction in a predetermined direction.
[0024]
　This makes it possible, for example, to adaptively control the range of use of the image used for in-screen prediction.
[0025]
　The above-mentioned technical features are specific examples of the embodiments of the present invention, and of course, the above-mentioned embodiments are not limited to the above-mentioned technical features.
[0026]
　<< 3. First Embodiment >> A first embodiment of
　the present invention will be described with reference to FIGS. 3 to 11.
[0027]
　<3.1. Configuration of In-Screen Predictor Device 100>
　An example of the configuration of the in-screen prediction device 100 according to the first embodiment will be described with reference to FIG. FIG. 3 is an explanatory diagram showing an example of a schematic configuration of the in-screen prediction device 100 according to the embodiment of the present invention. Referring to FIG. 3, the in-screen prediction device 100 includes an area control processing unit 110, a reference image generation unit 120, and a prediction image generation unit 130.
[0028]
　In the in-screen prediction device 100 having the above configuration, the area control processing unit 110 controls the use range (reference range) of the image (reconstructed image) used for the in-screen prediction. The reference image generation unit 120 generates a reference image from the reconstructed image based on the usage range controlled by the area control processing unit 110. The prediction image generation unit 130 generates a prediction image from the reference image generated by the reference image generation unit 120.
[0029]
　An example of the configuration of the area control processing unit 110 will be described with reference to FIG. FIG. 4 is a block diagram showing an example of a schematic configuration of the area control processing unit 110 according to the first embodiment. Referring to FIG. 4, the area control processing unit 110 includes a first out-licensing unit 111, a second out-licensing unit 113, and a control unit 115. The specific operations performed in each part will be described below.
[0030]
　<3.2. Technical Features>
　Next, the technical features according to the first embodiment will be described.
[0031]
　The area control processing unit 110 (control unit 115) predicts the screen based on the relationship between the position of the candidate image used for the screen prediction for the block to be processed and the position of the unit to which the block to be processed belongs. The partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined maximum range across the end of the unit in the predetermined direction in the range of use of the image used for.
[0032]
　The predetermined direction may be any direction such as the screen upward direction and the screen left direction, but the following description will be made mainly assuming that the screen upward direction is used.
　(1) Unit
　The unit includes a syntax structure for encoding a pixel sample. In particular, the unit is one coded tree unit contained in the slice. Since the unit includes the processing target block as described above, it can be regarded as a parent block. The above unit may be referred to as a "parent block".
[0033]
　(2) Predetermined maximum range
　The predetermined maximum range is specifically the maximum range that can be used for the in-screen prediction across the end of the coded tree unit in the predetermined direction.
[0034]
　For example, when the predetermined direction is the screen upward direction, the predetermined maximum range is used for the in-screen prediction from the upper end portion toward the screen upward direction with reference to the upper end portion of the coding tree unit. The maximum range that is possible (referenceable).
[0035]
　(3) The derivation and application
　area control processing unit 110 (first derivation unit 111) of the first boundary position is the coded tree unit based on the position of the coded tree unit and the predetermined maximum range. The first boundary position, which is an image position that can be used for the in-screen prediction and is the farthest from the coding tree unit in the predetermined direction, is derived so as to straddle the end portion in the predetermined direction.
[0036]
　For example, when the predetermined direction is the screen upward direction, the area control processing unit 110 (first derivation unit 111) is based on the position of the upper end portion of the coding tree unit and the predetermined maximum range. , The position farthest from the upper end of the coded tree unit in the upward direction on the screen is derived as the first boundary position.
[0037]
　When the first boundary position is derived in this way, the area control processing unit 110 (control unit 115) determines the relationship between the position of the candidate image used for the in-screen prediction and the first boundary position. Based on this, the partial range used for the in-screen prediction across the end of the coded tree unit in the predetermined direction is controlled to be equal to or less than the predetermined maximum range.
[0038]
　The area control processing unit 110 (control unit 115) is, for example, a candidate image that is farther from the first boundary position in the candidate images used for the in-screen prediction when viewed from the position of the processing target block. If there is an image, the partial range is controlled to be equal to or less than the predetermined maximum range.
[0039]
　(4) The derivation and application
　area control processing unit 110 (second derivation unit 113) of the second boundary position determines the position of the processing target block and the candidate image used in the predetermined direction in the in-screen prediction. Based on the candidate range, the position of the candidate image used for the in-screen prediction and the second boundary position farthest from the processing target block in the predetermined direction is derived.
[0040]
　For example, when the predetermined direction is the screen upward direction, the area control processing unit 110 (second derivation unit 113) determines the position of the upper end portion of the processing target block and the screen upward direction in the in-screen prediction. Based on the candidate range of the candidate image to be used, the candidate position of the candidate image farthest from the upper end of the processing target block in the upward direction on the screen is derived as the second boundary position.
[0041]
　When the second boundary position is derived in this way, the area control processing unit 110 (control unit 115) encodes the code based on the relationship between the first boundary position and the second boundary position. The partial range used for the in-screen prediction across the end of the tree unit in the predetermined direction is controlled to be equal to or less than the predetermined maximum range.
[0042]
　Specifically, when the area control processing unit 110 (control unit 115) is separated from the position of the processing target block by the second boundary position in the predetermined direction from the first boundary position. Controls the partial range used for the in-screen prediction across the end of the coded tree unit in the predetermined direction to be equal to or less than the predetermined maximum range.
[0043]
　For example, when the predetermined direction is the upward direction on the screen, the area control processing unit 110 (control unit 115) has the second boundary position with respect to the position of the upper end portion of the processing target block. When the distance from the boundary position of is on the screen, the partial range is controlled to be equal to or less than the predetermined maximum range.
[0044]
　Further, when the second boundary position is not separated from the first boundary position in the predetermined direction with respect to the position of the processing target block, the area control processing unit 110 (control unit 115) is used. The partial range used for the in-screen prediction is controlled to the candidate range across the end of the coded tree unit in the predetermined direction.
[0045]
　For example, when the predetermined direction is the upward direction on the screen, the area control processing unit 110 (control unit 115) has the second boundary position with respect to the position of the processing target block as the first boundary position. When the distance is not larger than that on the screen, the partial range is controlled to the candidate range.
[0046]
　<3.3. Specific Example>
　Next, a specific example of the processing performed by the in-screen prediction device 100 will be described.
[0047]
　(1) Area control processing unit 110
　A specific example of processing related to the area control processing unit 110 will be described. FIG. 5 is a diagram for explaining a specific example of processing related to the area control processing unit 110.
[0048]
　First, define the variables as follows.
[0049]
　As shown in FIG. 5, the predetermined maximum range that can be used (referenced) across the upper end of the coding tree unit 503 to which the processing target block 501 belongs is defined as a Kmax pixel. Further, the candidate range of the candidate image 505 (reference image) used for the in-screen prediction of the processing target block 501 in the upward direction of the screen is a Kup pixel, and the candidate range in the left direction of the screen is a Klepht pixel. In this specific example, Kmax is set to less than Kup for the sake of simplification of the description.
[0050]
　The usage range adaptively controlled by the area control processing unit 110 (control unit 115), that is, the usage range of the image (reconstructed image) used for in-screen prediction of the processing target block 501 in the screen direction is defined as K pixels. To do.
[0051]
　The picture is defined as follows. The upper left edge of the picture is set to the origin (x, y) = (0,0) of the horizontal / vertical coordinate system, the right direction of the screen is + x direction, and the lower direction of the screen is + y. Further, the number of horizontal pixels of the picture is w pixels, and the number of vertical pixels is h pixels.
[0052]
　Next, the processing target block is defined as follows. First, the coordinates of the upper left corner position of the processing target block are set to (cur_bx, cur_by). Further, the number of horizontal pixels of the image block to be processed is set to cur_bw pixels, and the number of vertical pixels is set to cur_bh pixels.
[0053]
　Next, the coded tree unit is defined as follows. Let the coordinates of the upper left corner position of the coded tree unit be (cur_cup, cur_cute). Further, the number of horizontal pixels of the coded tree unit is defined as a cup pixel, and the number of vertical pixels is defined as a cup pixel.
[0054]
　For the sake of brevity, cur_bw and cur_bh are less than cew and less than cuh, respectively. Further, since the upper left end of the picture is set as the origin (0,0) of the horizontal / vertical coordinate system as described above, the cur_cux and cur_kyuy are cur_bx or less and cur_by or less, respectively.
[0055]
　In this specific example, using the variables defined as described above, the candidate position of the image (reconstructed image) used (referenced) in the in-screen prediction of the processing target block and the coded tree unit to which the processing target block belongs. The candidate range K of the used image (reconstructed image) used (referenced) in the in-screen prediction is adaptively controlled based on the relationship with the position of.
[0056]
　First, the area control processing unit 110 (first derivation unit 111) derives the vertical coordinates ref_max_pos_y of the first boundary position using the following equation (1).
　ref_max_pos_y = cur_by-Kup ... (1)
[0057]
　Here, the vertical coordinates ref_max_pos_y of the first boundary position can be regarded as the maximum value of the vertical position that can be used (referenced) across the upper end of the coded tree unit in the upward direction of the screen.
[0058]
　Further, the area control processing unit 110 (second derivation unit 113) derives the vertical coordinates cand_min_pos_y of the second boundary position using the following equation (2).
　can_min_pos_y = cur_kyuy-Kmax ... (2)
[0059]
　Here, as described above, the vertical coordinate axis y takes a positive value in the downward direction of the screen with the upper end of the picture as the origin. Therefore, the vertical coordinate cand_min_pos_y of the second boundary position is used for the in-screen prediction of the processing target block ( It can be regarded as the minimum value of the candidate position of the image (reconstructed image) to be referred to).
[0060]
　The area control processing unit 110 (control unit 115) effectively controls the candidate range K by using the vertical coordinates ref_max_pos_y of the first boundary position and the vertical coordinates cand_min_pos_y of the second boundary position.
[0061]
　Specifically, in the case of cand_min_pos_y
　(1) Video Coding Device 800 The
　in-screen prediction device 100 described above can be applied to, for example, a video coding device 800 as shown in FIG.
[0079]
　FIG. 8 is a block diagram showing a schematic configuration of the video coding device 800. As shown in FIG. 8, the video coding device 800 includes a conversion / quantization unit 801, an entropy coding unit 802, an inverse conversion / inverse quantization unit 803, a buffer 804, and an in-screen prediction device 100. , And the multiplexing unit 806 is provided.
[0080]
　First, the prediction unit 805 generates a prediction signal for the input image signal for each block. Specifically, when performing in-screen prediction for a processing target block, the in-screen prediction device 100 generates a prediction signal for the processing target block as described above.
[0081]
　The conversion / quantization unit 801 frequency-converts a prediction error image obtained by subtracting the prediction signal from the input image signal. Further, the conversion / quantization unit 801 quantizes the frequency-converted prediction error image (conversion coefficient).
[0082]
　The entropy coding unit 802 entropy-codes the conversion quantization value and the difference information of the motion vector, which is a prediction parameter used by the prediction unit 805, based on, for example, CABAC (Context-based Adaptive Binary Arithmetic Coding). ..
[0083]
　The inverse transformation / inverse quantization unit 803 inversely quantizes the transformation quantization value. Further, the inverse conversion / inverse quantization unit 803 performs inverse frequency conversion of the inverse quantization frequency conversion coefficient. The inverse frequency converted reconstruction prediction error image is supplied to the buffer 804 with a prediction signal added. The buffer 804 stores the reconstructed image.
[0084]
　The multiplexing unit 806 multiplexes the codeword supplied from the entropy encoding unit 802 as a bit stream.
[0085]
　The video coding device 800 that generates a bitstream by the above-described operation uses an image (reference image) used for in-screen prediction for each processing target block by the in-screen prediction device 100 included in the prediction unit 805. The range is adaptively controlled. This makes it possible to output a video-coded bit stream while reducing the size requirement of the line buffer.
[0086]
　(2) Video Decoding Device 900 The
　in-screen prediction device 100 described above can be applied to, for example, a video decoding device 900 as shown in FIG.
[0087]
　FIG. 9 is a block diagram showing a schematic configuration of the video decoding device 900. As shown in FIG. 9, the video decoding device 900 includes a multiplexing release unit 901, an entropy decoding unit 902, an inverse conversion / inverse quantization unit 903, a prediction unit 904 including the in-screen prediction device 100 described above, and a buffer 905. It also includes a control information generation unit 906.
[0088]
　The demultiplexing unit 901 demultiplexes the input bit stream and extracts the codeword.
[0089]
　The entropy decoding unit 902 entropy-decodes the codeword extracted by the demultiplexing unit 901, for example, based on CABAC. The conversion quantization value entropy-decoded by the entropy decoding unit 902 is supplied to the inverse conversion / inverse quantization unit 903. Further, the difference information of the motion vector is supplied to the prediction unit 904.
[0090]
　The inverse conversion / inverse quantization unit 903 inversely quantizes the transformation quantization value at the quantization step width. Further, the inverse conversion / inverse quantization unit 903 reverse-frequency-converts the inverse-quantized frequency conversion coefficient.
[0091]
　The prediction unit 904 generates a prediction signal for each block. When performing in-screen prediction for the processing target block, the in-screen prediction device 100 generates a prediction signal for the processing target block as described above.
[0092]
　The reconstruction prediction error image that has been inversely frequency-converted by the inverse conversion / inverse quantization unit 903 is supplied to the buffer 905 as a reconstruction picture by adding the prediction signal supplied from the prediction unit 904. Then, the reconstructed picture stored in the buffer 905 is output as a decoded image.
[0093]
　The video decoding device 900 that generates a decoded image from the bit stream by the above-described operation is an image (reconstructed image) used for in-screen prediction for each processing target block by the in-screen prediction device 100 included in the prediction unit 904. ) Use range (reference range) is adaptively controlled. This makes it possible to generate a decoded image from the bitstream while reducing the size requirement of the line buffer.
[0094]
　(3) Information Processing System 1000 The
　in-screen prediction device 100 described above may be realized by, for example, the information processing system 1000 as shown in FIG.
[0095]
　FIG. 10 is a block diagram showing a schematic configuration of an information processing system 1000 to which the in-screen prediction device 100 is applied.
[0096]
　As shown in FIG. 10, the information processing system 1000 includes a processor 1001, a program memory 1002, a storage medium 1003 for storing video data, and a storage medium 1004 for storing a bit stream. The storage medium 1003 and the storage medium 1004 may be separate storage media or may be storage areas made of the same storage medium. As the storage medium, a magnetic storage medium such as a hard disk can be used.
[0097]
　By installing a computer program that realizes the functions of the in-screen prediction device 100 in the program memory 1002, the information processing system 1000 uses a range of images (reconstructed images) used for in-screen prediction for each processing target block (reconstructed image). Reference range) is adaptively controlled. This makes it possible to generate a decoded image from the bitstream while reducing the size requirement of the line buffer.
[0098]
　(4) Interoperability
　FIG. 11 is a diagram showing a system in which the above-mentioned video coding device 800 and the above-mentioned video decoding device 900 are connected by a transmission line 300 such as a wireless transmission line or a wired transmission line.
[0099]
　In a system as shown in FIG. 11, a reference used by a video coding device 800 and a video decoding device 900 for in-screen prediction for each processing target block in a common procedure such as using a common Kmax, Kup, Kleft, etc. By adaptively controlling the range of the image, the interoperability between the video coding device 800 and the video decoding device 900 can be ensured.
[0100]
　Specifically, as the predetermined maximum value Kmax, a fixed value common to the video coding device 800 and the video decoding device 900 can be used. Further, the predetermined maximum value Kmax is set to a variable value implicitly set based on the number of horizontal pixels and the number of vertical pixels of the picture, for example, the value is set to a small value as the number of pixels of the picture increases. You may.
[0101]
　As described above, when the predetermined maximum value Kmax is a variable value, the predetermined maximum value Kmax is not limited to the case of being implicitly set. For example, the value may be explicitly signaled as a bitstream syntax element. That is, the information that specifies the predetermined maximum range Kmax may be included in the bit stream as a syntax element. The information for specifying the predetermined maximum range Kmax may be included, for example, for each sequence, each picture, each slice, or each unit.
[0102]
　Further, the candidate ranges Kup and Kleft may also be variable values. In this case, the candidate ranges Kup and Kleft may be explicitly signaled as a bitstream syntax element.
[0103]
　<3.5. Modification example> In the
　present embodiment, the range of use in the upward direction of the screen is adaptively controlled among the images used for in-screen prediction for each block to be processed, but the present invention is not limited to this, and similarly, the left direction of the screen The range of use may also be adaptively controlled.
[0104]
　Specifically, the area control processing unit 110 (control unit 115) of the in-screen prediction device 100 straddles the left end of the unit in the usage range of the image used for in-screen prediction in the screen to the left. The subrange used for prediction may be controlled below a predetermined maximum range. In such a modification, the predetermined maximum range is specifically the maximum range that can be used for in-screen prediction across the left end of the coded tree unit in the left direction of the screen.
[0105]
　Further, the information for specifying the predetermined maximum range may be signaled from the video coding device 800 to the video decoding device 900 as a bitstream syntax element.
[0106]
　<< 4. Second Embodiment >>
　Subsequently, a second embodiment of the present invention will be described with reference to FIGS. 12 and 13. The first embodiment described above is a specific embodiment, but the second embodiment is a more generalized embodiment.
[0107]
　<4.1. Configuration>
　FIG. 12 is a block diagram showing an example of a schematic configuration of the video coding apparatus 800 according to the second embodiment. Referring to FIG. 12, the video coding device 800 includes a control unit 810.
[0108]
　FIG. 13 is a block diagram showing an example of a schematic configuration of the video decoding apparatus 900 according to the second embodiment. Referring to FIG. 13, the video decoding device 900 includes a control unit 910.
[0109]
　<4.2. Technical Features>
　Next, the technical features of the second embodiment will be described.
[0110]
　In the second embodiment, the video coding device 800 (control unit 810) determines the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. Based on this, the partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined maximum range across the end of the unit in the use range of the image used for the in-screen prediction in a predetermined direction.
[0111]
　For example, the video coding device 800 may operate the in-screen prediction device 100 according to the first embodiment.
[0112]
　Further, the video decoding device 900 (control unit 910) in the screen is based on the relationship between the position of the candidate image used for in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. Of the range of use of the image used for prediction, the partial range used for the in-screen prediction straddles the end of the unit in a predetermined direction and is controlled to be equal to or less than a predetermined maximum range.
[0113]
　For example, the video decoding device 900 may operate the in-screen prediction device 100 according to the first embodiment.
[0114]
　The second embodiment has been described above. According to the second embodiment, for example, it is possible to adaptively control the range of use of the image used for the in-screen prediction.
[0115]
　<< 5. Other Embodiments >> Although the embodiments of
　the present invention have been described above, the present invention is not limited to these embodiments. It will be appreciated by those skilled in the art that these embodiments are merely exemplary and that various modifications are possible without departing from the scope and spirit of the invention.
[0116]
　For example, the steps in the processes described herein do not necessarily have to be performed in chronological order in the order described in the sequence diagram. For example, the steps in the process may be executed in an order different from the order described in the sequence diagram, or may be executed in parallel. In addition, some of the steps in the process may be deleted, and additional steps may be added to the process.
[0117]
　Further, a method including processing of the components of the device described in the present specification (for example, a first derivation unit, a second derivation unit, and / or a control unit) may be provided, and processing of the above components may be provided. May be provided to cause the processor to execute. In addition, a non-transitory computer readable medium may be provided that can be read by the computer on which the program is recorded. Of course, such devices, modules, methods, programs, and computer-readable non-temporary recording media are also included in the present invention.
[0118]
　Some or all of the above embodiments may also be described, but not limited to:
[0119]
　(Appendix 1) The
　range of use of the image used for the in-screen prediction based on the relationship between the position of the candidate image used for the in-screen prediction for the processing target block and the position of the unit to which the processing target block belongs. A video coding or video decoding device including a control unit that controls a partial range used for in-screen prediction to be equal to or less than a predetermined maximum range across the end of the unit in a predetermined direction.
[0120]
　(Supplementary Note 2)
　The video coding or video decoding apparatus according to Supplementary note 1, wherein the unit includes a syntax structure for encoding a pixel sample.
[0121]
　(Appendix 3)
　The video coding or video decoding device according to Appendix 1 or 2, wherein the unit is one coding tree unit included in a slice.
[0122]
　(Supplementary Note 4)
　The video code according to any one of Supplementary note 1 to 3, wherein the predetermined maximum range is the maximum range that can be used for the in-screen prediction across the end of the unit in the predetermined direction. Or video decoding device.
[0123]
　(Appendix 5)
　Based on the position of the unit and the predetermined maximum range, the image position that can be used for the in-screen prediction across the end of the unit in the predetermined direction and is in the predetermined direction from the unit. The
　control unit further includes a first derivation unit for deriving the first boundary position farthest from the screen, and the control unit is based on the relationship between the position of the candidate image used for the in-screen prediction and the first boundary position. The video coding or video decoding device according to Appendix 4, wherein the partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined range across the end of the unit in the predetermined direction.
[0124]
　(Appendix 6)
　The position of the candidate image used for the in-screen prediction based on the position of the processing target block and the candidate range of the candidate image used in the predetermined direction in the in-screen prediction. Further, a second derivation unit for deriving the second boundary position farthest from the processing target block in the predetermined direction is further provided, and the
　control unit is based on the relationship between the first boundary position and the second boundary position. The video coding or video decoding device according to Appendix 5, wherein the partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined maximum range across the end of the unit in the predetermined direction.
[0125]
　(Appendix 7)
　When the second boundary position is separated from the first boundary position in the predetermined direction with respect to the position of the processing target block, the control unit is an end portion of the unit. The video coding or video decoding apparatus according to Appendix 6, wherein the partial range used for the in-screen prediction is controlled to be equal to or less than the predetermined maximum range.
[0126]
　(Appendix 8)
　When the second boundary position is not separated from the first boundary position in the predetermined direction with respect to the position of the processing target block, the control unit makes an in-screen prediction. The video coding or video decoding apparatus according to Appendix 6 or 7, which controls the usage range of the image to be used to the candidate range.
[0127]
　(Appendix 9) The
　predetermined direction is the screen upward direction, and the
　predetermined maximum range is the maximum range Kmax that can be used for the in-screen prediction across the upper end portion of the unit in the screen upward direction, and the
　candidate range. Is a candidate range Kup of the candidate image used in the upward direction of the screen in the in-screen prediction, and
　the first derivation unit is based on a vertical coordinate axis having a positive value in the downward direction of the screen with the upper end of the picture as the origin. The vertical coordinate ref_max_pos_y of the first boundary position is derived using the following equation (1), and
　the second derivation unit uses the following equation (2) based on the vertical coordinate axis to derive the second boundary position. The vertical coordinates cand_min_pos_y of the
　above are derived, and in the case of cand_min_pos_y