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WO2018110180A1 - Dispositif de génération de vecteur de mouvement, dispositif de génération d'image prédite, dispositif de décodage d'image animée, et dispositif de codage d'image animée - Google Patents

Dispositif de génération de vecteur de mouvement, dispositif de génération d'image prédite, dispositif de décodage d'image animée, et dispositif de codage d'image animée Download PDF

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WO2018110180A1
WO2018110180A1 PCT/JP2017/040838 JP2017040838W WO2018110180A1 WO 2018110180 A1 WO2018110180 A1 WO 2018110180A1 JP 2017040838 W JP2017040838 W JP 2017040838W WO 2018110180 A1 WO2018110180 A1 WO 2018110180A1
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motion vector
matching
unit
prediction
search
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Japanese (ja)
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貴也 山本
知典 橋本
知宏 猪飼
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Sharp Corp
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Sharp Corp
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H04N19/533—Motion estimation using multistep search, e.g. 2D-log search or one-at-a-time search [OTS]

Definitions

  • the present invention relates to a motion vector generation device, a predicted image generation device, a moving image decoding device, and a moving image encoding device.
  • a moving image encoding device that generates encoded data by encoding the moving image, and a moving image that generates a decoded image by decoding the encoded data
  • An image decoding device is used.
  • the moving image encoding method include a method proposed in H.264 / AVC and HEVC (High-Efficiency Video Coding).
  • an image (picture) constituting a moving image is a slice obtained by dividing the image, a coding unit obtained by dividing the slice (coding unit (Coding Unit : CU)), and a hierarchical structure consisting of a prediction unit (PU) and a transform unit (TU) that are obtained by dividing a coding unit. Decrypted.
  • a predicted image is usually generated based on a local decoded image obtained by encoding / decoding an input image, and the predicted image is generated from the input image (original image).
  • a prediction residual obtained by subtraction (sometimes referred to as “difference image” or “residual image”) is encoded. Examples of the method for generating a predicted image include inter-screen prediction (inter prediction) and intra-screen prediction (intra prediction).
  • Non-patent Document 1 using a matching technique (template matching and bilateral matching) for deriving a motion vector on the decoder side can be cited as a moving picture encoding and decoding technique in recent years.
  • Non-Patent Document 2 describes bilateral template matching as a new matching technique.
  • the matching technique disclosed in Non-Patent Document 1 and Non-Patent Document 2 has a first problem that a predicted image with sufficient prediction accuracy cannot be generated. Further, the matching technique disclosed in Non-Patent Document 1 has a second problem that the amount of processing for motion vector search necessary for predictive image generation increases.
  • the present invention provides a motion vector generation device, a predicted image generation device, a moving image decoding device, and a moving image encoding device capable of solving at least one of the first and second problems. is there.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a merge processing unit that derives a motion vector for each prediction block by merge processing and a prediction block generated from the motion vector derived by the merge processing unit as a template and matching using bilateral template matching (BTM)
  • BTM bilateral template matching
  • a BTM processing unit that executes processing and corrects the motion vector, and the BTM processing unit performs the matching processing by performing the bilateral template matching a plurality of times.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • the first motion vector search unit for searching for a motion vector for each prediction block by the first matching process and the motion vector selected by the first motion vector search unit are referred to in the prediction block.
  • a second motion vector search unit that searches for a motion vector by a second matching process for each of the plurality of sub-blocks included, and the first motion vector search unit performs an initial vector search for a prediction block. And the second motion vector is searched for a motion vector by performing a local search.
  • the search unit searches for a motion vector by performing a local search after performing an initial vector search for a sub-block, and the motion vector searched by the first motion vector search unit, or A BTM processor that corrects the motion vector by executing a third matching process using bilateral template matching (BTM) using a prediction block generated from the motion vector searched by the second motion vector search unit as a template.
  • BTM bilateral template matching
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a first motion vector search unit that searches for a motion vector for each prediction block by matching processing, and a plurality of motion vectors selected by the first motion vector search unit are included in the prediction block.
  • a second motion vector search unit that searches for a motion vector by matching processing for each of the sub-blocks, and the first motion vector search unit performs an initial vector search for the prediction block and then performs local vector search.
  • the second motion vector search unit searches for a motion vector by performing a general search.
  • a motion vector is searched by performing a local search after performing an initial vector search for a block.
  • the first motion vector search unit is obtained by template matching when bilateral matching is performed.
  • the initial vector search is performed by adding the motion vector to the initial vector candidate in the bilateral matching.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a first motion vector search unit that searches for a motion vector for each prediction block by matching processing, and a plurality of motion vectors selected by the first motion vector search unit are included in the prediction block.
  • a second motion vector search unit that searches for a motion vector by matching processing for each of the sub-blocks, and the first motion vector search unit performs an initial vector search for the prediction block and then performs local vector search.
  • the second motion vector search unit searches for a motion vector by performing a general search.
  • a motion vector is searched by performing a local search, and the second motion vector search unit is adjacent to the top or left of the target sub-block.
  • the initial vector search is performed by adding the motion vector of the existing sub-block to the initial vector candidate.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a first motion vector search unit that searches for a motion vector for each prediction block by matching processing, and a plurality of motion vectors selected by the first motion vector search unit are included in the prediction block.
  • a second motion vector search unit that searches for a motion vector by matching processing for each of the sub-blocks, and the first motion vector search unit performs an initial vector search for the prediction block and then performs local vector search.
  • the second motion vector search unit searches for a motion vector by performing a general search.
  • a motion vector is searched by performing a local search after performing an initial vector search for a block.
  • the first motion vector search unit and the second motion vector search unit perform template matching.
  • the configuration is such that the matching process with another reference picture is executed using a prediction block created from the result of the matching process with one of the reference pictures as a template.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a first motion vector search unit that searches for a motion vector for each prediction block by matching processing, and a plurality of motion vectors selected by the first motion vector search unit are included in the prediction block.
  • a second motion vector search unit that searches for a motion vector by matching processing for each of the sub-blocks, and the first motion vector search unit performs an initial vector search for the prediction block and then performs local vector search.
  • the second motion vector search unit searches for a motion vector by performing a general search.
  • a motion vector is searched by performing a local search after performing an initial vector search for a block.
  • the first motion vector search unit and the second motion vector search unit perform template matching. When executed, only the matching process with one reference picture is executed.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a first motion vector search unit that searches for a motion vector for each prediction block by matching processing, and a plurality of motion vectors selected by the first motion vector search unit are included in the prediction block.
  • a second motion vector search unit that searches for a motion vector by matching processing for each of the sub-blocks, and the first motion vector search unit performs an initial vector search for the prediction block and then performs local vector search.
  • the second motion vector search unit searches for a motion vector by performing a general search.
  • the first motion vector search unit and the second motion vector search unit search for a motion vector by performing a local search after performing an initial vector search for a block.
  • the matching process is executed using template matching or bilateral matching according to the shape of the image.
  • a motion vector generation device generates a motion vector that is referred to in order to generate a prediction image used for encoding or decoding of a moving image.
  • a first motion vector search unit that searches for a motion vector for each prediction block by matching processing, and a plurality of motion vectors selected by the first motion vector search unit are included in the prediction block.
  • a second motion vector search unit that searches for a motion vector by matching processing for each of the sub-blocks, and the first motion vector search unit performs an initial vector search for the prediction block and then performs local vector search.
  • the second motion vector search unit searches for a motion vector by performing a general search. After performing an initial vector search for a block, a motion vector is searched by performing a local search.
  • the first motion vector search unit and the second motion vector search unit include template matching and The initial vector search and the local search are executed in accordance with which of the bilateral matching is used.
  • FIG. 1 It is a figure which shows the hierarchical structure of the data of the encoding stream which concerns on this embodiment. It is a figure which shows the pattern of PU division
  • FIG. It is a figure for demonstrating the acquisition method of the template in other embodiment, (a) is a figure which shows the acquisition method of the template in Embodiment 1, (b) shows the acquisition method of the template in this embodiment.
  • FIG. It is a figure which shows the flow of the template matching process in other embodiment. It is a figure for demonstrating the process which determines the matching mode in embodiment, (a) is a table which shows the relationship between a parameter and a matching mode, (b) is a part of flowchart which shows the flow of a process. . It is a flowchart which shows the flow of the process in other embodiment. It is a flowchart which shows the flow of a process of the process example in other embodiment.
  • FIG. 43 is a schematic diagram showing a configuration of the image transmission system 1 according to the present embodiment.
  • the image transmission system 1 is a system that transmits a code obtained by encoding an encoding target image, decodes the transmitted code, and displays an image.
  • the image transmission system 1 includes an image encoding device (moving image encoding device, predicted image generating device) 11, a network 21, an image decoding device (moving image decoding device, predicted image generating device) 31, and an image display device 41. Composed.
  • the image encoding device 11 receives an image T indicating a single layer image or a plurality of layers.
  • a layer is a concept used to distinguish a plurality of pictures when there are one or more pictures constituting a certain time. For example, when the same picture is encoded with a plurality of layers having different image quality and resolution, scalable encoding is performed, and when a picture of a different viewpoint is encoded with a plurality of layers, view scalable encoding is performed.
  • inter-layer prediction, inter-view prediction When prediction is performed between pictures of a plurality of layers (inter-layer prediction, inter-view prediction), encoding efficiency is greatly improved. Further, even when prediction is not performed (simultaneous casting), encoded data can be collected.
  • the network 21 transmits the encoded stream Te generated by the image encoding device 11 to the image decoding device 31.
  • the network 21 is the Internet, a wide area network (WAN: Wide Area Network), a small network (LAN: Local Area Network), or a combination thereof.
  • the network 21 is not necessarily limited to a bidirectional communication network, and may be a unidirectional communication network that transmits broadcast waves such as terrestrial digital broadcasting and satellite broadcasting.
  • the network 21 may be replaced with a storage medium that records an encoded stream Te such as a DVD (Digital Versatile Disc) or a BD (Blue-ray Disc).
  • the image decoding device 31 decodes each of the encoded streams Te transmitted by the network 21, and generates one or a plurality of decoded images Td decoded.
  • the image display device 41 displays all or part of one or more decoded images Td generated by the image decoding device 31.
  • the image display device 41 includes, for example, a display device such as a liquid crystal display or an organic EL (Electro-luminescence) display.
  • a display device such as a liquid crystal display or an organic EL (Electro-luminescence) display.
  • a high-quality enhancement layer image is displayed and only a lower processing capability is provided. Displays a base layer image that does not require higher processing capability and display capability as an extension layer.
  • X? Y: z is a ternary operator that takes y when x is true (non-zero) and takes z when x is false (0).
  • FIG. 1 is a diagram showing a hierarchical structure of data in the encoded stream Te.
  • the encoded stream Te illustratively includes a sequence and a plurality of pictures constituting the sequence.
  • (A) to (f) of FIG. 1 respectively show an encoded video sequence defining a sequence SEQ, an encoded picture defining a picture PICT, an encoded slice defining a slice S, and an encoded slice defining a slice data
  • the encoded video sequence In the encoded video sequence, a set of data referred to by the image decoding device 31 for decoding the sequence SEQ to be processed is defined. As shown in FIG. 1A, the sequence SEQ includes a video parameter set (Video Parameter Set), a sequence parameter set SPS (Sequence Parameter Set), a picture parameter set PPS (Picture Parameter Set), a picture PICT, and an additional extension. Information SEI (Supplemental Enhancement Information) is included. Here, the value indicated after # indicates the layer ID.
  • FIG. 1 shows an example in which encoded data of # 0 and # 1, that is, layer 0 and layer 1, exists, the type of layer and the number of layers are not dependent on this.
  • the video parameter set VPS is a set of encoding parameters common to a plurality of moving images, a plurality of layers included in the moving image, and encoding parameters related to individual layers in a moving image composed of a plurality of layers.
  • a set is defined.
  • the sequence parameter set SPS defines a set of encoding parameters that the image decoding device 31 refers to in order to decode the target sequence. For example, the width and height of the picture are defined. A plurality of SPSs may exist. In that case, one of a plurality of SPSs is selected from the PPS.
  • a set of encoding parameters referred to by the image decoding device 31 in order to decode each picture in the target sequence is defined.
  • a quantization width reference value (pic_init_qp_minus26) used for picture decoding and a flag (weighted_pred_flag) indicating application of weighted prediction are included.
  • the picture PICT includes slices S0 to SNS-1 (NS is the total number of slices included in the picture PICT).
  • the coded slice In the coded slice, a set of data referred to by the image decoding device 31 for decoding the slice S to be processed is defined. As shown in FIG. 1C, the slice S includes a slice header SH and slice data SDATA.
  • the slice header SH includes an encoding parameter group that is referred to by the image decoding device 31 in order to determine a decoding method of the target slice.
  • Slice type designation information (slice_type) for designating a slice type is an example of an encoding parameter included in the slice header SH.
  • I slice using only intra prediction at the time of encoding (2) P slice using unidirectional prediction or intra prediction at the time of encoding, (3) B-slice using unidirectional prediction, bidirectional prediction, or intra prediction at the time of encoding may be used.
  • the slice header SH may include a reference (pic_parameter_set_id) to the picture parameter set PPS included in the encoded video sequence.
  • the slice data SDATA includes a coding tree unit (CTU: Coding Tree Unit) as shown in FIG.
  • a CTU is a block of a fixed size (for example, 64x64) that constitutes a slice, and is sometimes called a maximum coding unit (LCU: Large Coding Unit).
  • Encoding tree unit As shown in (e) of FIG. 1, a set of data referred to by the image decoding device 31 in order to decode the encoding tree unit to be processed is defined.
  • the coding tree unit is divided by recursive quadtree division.
  • a tree-structured node obtained by recursive quadtree partitioning is referred to as a coding node (CN).
  • An intermediate node of the quadtree is an encoding node, and the encoding tree unit itself is defined as the highest encoding node.
  • the CTU includes a split flag (cu_split_flag), and when cu_split_flag is 1, it is split into four coding nodes CN.
  • the coding node CN is not divided and has one coding unit (CU: Coding Unit) as a node.
  • CU Coding Unit
  • the encoding unit CU is a terminal node of the encoding node and is not further divided.
  • the encoding unit CU is a basic unit of the encoding process.
  • the size of the coding tree unit CTU is 64 ⁇ 64 pixels
  • the size of the coding unit can be any of 64 ⁇ 64 pixels, 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, and 8 ⁇ 8 pixels.
  • the encoding unit As shown in (f) of FIG. 1, a set of data referred to by the image decoding device 31 in order to decode an encoding unit to be processed is defined. Specifically, the encoding unit includes a prediction tree, a conversion tree, and a CU header CUH. In the CU header, a prediction mode, a division method (PU division mode), and the like are defined.
  • prediction information (a reference picture index, a motion vector, etc.) of each prediction unit (PU) obtained by dividing the coding unit into one or a plurality is defined.
  • the prediction unit is one or a plurality of non-overlapping areas constituting the encoding unit.
  • the prediction tree includes one or a plurality of prediction units obtained by the above-described division.
  • a prediction unit obtained by further dividing the prediction unit is referred to as a “sub-block”.
  • the sub block is composed of a plurality of pixels.
  • the number of sub-blocks in the prediction unit is one.
  • the prediction unit is larger than the size of the sub-block, the prediction unit is divided into sub-blocks. For example, when the prediction unit is 8 ⁇ 8 and the sub-block is 4 ⁇ 4, the prediction unit is divided into four sub-blocks that are divided into two horizontally and two vertically.
  • the prediction process may be performed for each prediction unit (sub block).
  • Intra prediction is prediction within the same picture
  • inter prediction refers to prediction processing performed between different pictures (for example, between display times and between layer images).
  • the division method is encoded by the PU division mode (part_mode) of encoded data, 2Nx2N (same size as the encoding unit), 2NxN, 2NxnU, 2NxnD, Nx2N, nLx2N, nRx2N, and NxN etc.
  • 2NxN and Nx2N indicate 1: 1 symmetrical division
  • 2NxnU, 2NxnD and nLx2N and nRx2N indicate 1: 3 and 3: 1 asymmetric division.
  • the PUs included in the CU are expressed as PU0, PU1, PU2, and PU3 in this order.
  • FIG. 2 specifically illustrate the shape of the partition (the position of the boundary of the PU partition) in each PU partition mode.
  • 2A shows a 2Nx2N partition
  • FIGS. 2B, 2C, and 2D show 2NxN, 2NxnU, and 2NxnD partitions (horizontal partitions), respectively.
  • E), (f), and (g) show partitions (vertical partitions) in the case of Nx2N, nLx2N, and nRx2N, respectively, and (h) shows an NxN partition.
  • the horizontal partition and the vertical partition are collectively referred to as a rectangular partition
  • 2Nx2N and NxN are collectively referred to as a square partition.
  • the encoding unit is divided into one or a plurality of conversion units, and the position and size of each conversion unit are defined.
  • a transform unit is one or more non-overlapping areas that make up a coding unit.
  • the conversion tree includes one or a plurality of conversion units obtained by the above division.
  • the division in the conversion tree includes a case where an area having the same size as that of the encoding unit is assigned as a conversion unit, and a case where recursive quadtree division is used, similar to the above-described CU division.
  • Conversion processing is performed for each conversion unit.
  • the prediction parameter includes prediction list use flags predFlagL0 and predFlagL1, reference picture indexes refIdxL0 and refIdxL1, and motion vectors mvL0 and mvL1.
  • the prediction list use flags predFlagL0 and predFlagL1 are flags indicating whether or not reference picture lists called L0 list and L1 list are used, respectively, and a reference picture list corresponding to a value of 1 is used.
  • flag indicating whether or not it is XX when “flag indicating whether or not it is XX” is described, when the flag is not 0 (for example, 1) is XX, 0 is not XX, and logical negation, logical product, etc. 1 is treated as true and 0 is treated as false (the same applies hereinafter).
  • flag when the flag is not 0 (for example, 1) is XX, 0 is not XX, and logical negation, logical product, etc. 1 is treated as true and 0 is treated as false (the same applies hereinafter).
  • other values can be used as true values and false values in an actual apparatus or method.
  • Syntax elements for deriving inter prediction parameters included in the encoded data include, for example, PU partition mode part_mode, merge flag merge_flag, merge index merge_idx, inter prediction identifier inter_pred_idc, reference picture index refIdxLX, prediction vector index mvp_LX_idx, There is a difference vector mvdLX.
  • the reference picture list is a list including reference pictures stored in the reference picture memory 306.
  • FIG. 3 is a conceptual diagram illustrating an example of a reference picture and a reference picture list.
  • a rectangle is a picture
  • an arrow is a reference relationship of the picture
  • a horizontal axis is time
  • I, P, and B in the rectangle are an intra picture
  • a single prediction picture a bi-prediction picture
  • numbers in the rectangle are Indicates the decoding order.
  • the decoding order of pictures is I0, P1, B2, B3, and B4
  • the display order is I0, B3, B2, B4, and P1.
  • FIG. 3B shows an example of the reference picture list.
  • the reference picture list is a list representing candidate reference pictures, and one picture (slice) may have one or more reference picture lists.
  • the target picture B3 has two reference picture lists, an L0 list RefPicList0 and an L1 list RefPicList1.
  • the reference pictures are I0, P1, and B2, and the reference picture has these pictures as elements.
  • refIdxLX the reference picture index
  • the figure shows an example in which reference pictures P1 and B2 are referenced by refIdxL0 and refIdxL1.
  • the prediction parameter decoding (encoding) method includes a merge prediction (merge) mode and an AMVP (Adaptive Motion Vector Prediction) mode.
  • the merge flag merge_flag is a flag for identifying these.
  • the merge prediction mode is a mode in which the prediction list use flag predFlagLX (or inter prediction identifier inter_pred_idc), the reference picture index refIdxLX, and the motion vector mvLX are not included in the encoded data and are derived from the prediction parameters of already processed neighboring PUs.
  • the AMVP mode is a mode in which the inter prediction identifier inter_pred_idc, the reference picture index refIdxLX, and the motion vector mvLX are included in the encoded data.
  • the motion vector mvLX is encoded as a prediction vector index mvp_LX_idx for identifying the prediction vector mvpLX and a difference vector mvdLX.
  • the inter prediction identifier inter_pred_idc is a value indicating the type and number of reference pictures, and takes one of PRED_L0, PRED_L1, and PRED_BI.
  • PRED_L0 and PRED_L1 indicate that reference pictures managed by the reference picture lists of the L0 list and the L1 list are used, respectively, and that one reference picture is used (single prediction).
  • PRED_BI indicates that two reference pictures are used (bi-prediction BiPred), and reference pictures managed by the L0 list and the L1 list are used.
  • the prediction vector index mvp_LX_idx is an index indicating a prediction vector
  • the reference picture index refIdxLX is an index indicating a reference picture managed in the reference picture list.
  • LX is a description method used when L0 prediction and L1 prediction are not distinguished from each other. By replacing LX with L0 and L1, parameters for the L0 list and parameters for the L1 list are distinguished.
  • the merge index merge_idx is an index that indicates whether one of the prediction parameter candidates (merge candidates) derived from the processed PU is used as the prediction parameter of the decoding target PU.
  • the motion vector mvLX indicates a shift amount between blocks on two different pictures.
  • a prediction vector and a difference vector related to the motion vector mvLX are referred to as a prediction vector mvpLX and a difference vector mvdLX, respectively.
  • Inter prediction identifier inter_pred_idc and prediction list use flag predFlagLX The relationship between the inter prediction identifier inter_pred_idc and the prediction list use flags predFlagL0 and predFlagL1 is as follows and can be converted into each other.
  • the flag biPred as to whether it is a bi-prediction BiPred can be derived depending on whether the two prediction list use flags are both 1. For example, it can be derived by the following formula.
  • the flag biPred can also be derived depending on whether or not the inter prediction identifier is a value indicating that two prediction lists (reference pictures) are used. For example, it can be derived by the following formula.
  • FIG. 5 is a schematic diagram illustrating a configuration of the image decoding device 31 according to the present embodiment.
  • the image decoding device 31 includes an entropy decoding unit 301, a prediction parameter decoding unit (prediction image decoding device) 302, a loop filter 305, a reference picture memory 306, a prediction parameter memory 307, a prediction image generation unit (prediction image generation device) 308, and inversely.
  • a quantization / inverse DCT unit 311 and an addition unit 312 are included.
  • the prediction parameter decoding unit 302 includes an inter prediction parameter decoding unit 303 and an intra prediction parameter decoding unit 304.
  • the predicted image generation unit 308 includes an inter predicted image generation unit 309 and an intra predicted image generation unit 310.
  • the entropy decoding unit 301 performs entropy decoding on the coded stream Te input from the outside, and separates and decodes individual codes (syntax elements).
  • the separated codes include prediction information for generating a prediction image and residual information for generating a difference image.
  • the entropy decoding unit 301 outputs a part of the separated code to the prediction parameter decoding unit 302.
  • Some of the separated codes are, for example, a prediction mode predMode, a PU partition mode part_mode, a merge flag merge_flag, a merge index merge_idx, an inter prediction identifier inter_pred_idc, a reference picture index refIdxLX, a prediction vector index mvp_LX_idx, and a difference vector mvdLX.
  • Control of which code is decoded is performed based on an instruction from the prediction parameter decoding unit 302.
  • the entropy decoding unit 301 outputs the quantization coefficient to the inverse quantization / inverse DCT unit 311.
  • the quantization coefficient is a coefficient obtained by performing quantization by performing DCT (Discrete Cosine Transform) on the residual signal in the encoding process.
  • the inter prediction parameter decoding unit 303 decodes the inter prediction parameter with reference to the prediction parameter stored in the prediction parameter memory 307 based on the code input from the entropy decoding unit 301.
  • the inter prediction parameter decoding unit 303 outputs the decoded inter prediction parameter to the prediction image generation unit 308 and stores it in the prediction parameter memory 307. Details of the inter prediction parameter decoding unit 303 will be described later.
  • the intra prediction parameter decoding unit 304 refers to the prediction parameter stored in the prediction parameter memory 307 on the basis of the code input from the entropy decoding unit 301 and decodes the intra prediction parameter.
  • the intra prediction parameter is a parameter used in a process of predicting a CU within one picture, for example, an intra prediction mode IntraPredMode.
  • the intra prediction parameter decoding unit 304 outputs the decoded intra prediction parameter to the prediction image generation unit 308 and stores it in the prediction parameter memory 307.
  • the intra prediction parameter decoding unit 304 may derive different intra prediction modes depending on luminance and color difference.
  • the intra prediction parameter decoding unit 304 decodes the luminance prediction mode IntraPredModeY as the luminance prediction parameter and the color difference prediction mode IntraPredModeC as the color difference prediction parameter.
  • the luminance prediction mode IntraPredModeY is a 35 mode, and corresponds to planar prediction (0), DC prediction (1), and direction prediction (2 to 34).
  • the color difference prediction mode IntraPredModeC uses one of the planar prediction (0), the DC prediction (1), the direction prediction (2 to 34), and the LM mode (35).
  • the intra prediction parameter decoding unit 304 decodes a flag indicating whether IntraPredModeC is the same mode as the luminance mode. If the flag indicates that the mode is the same as the luminance mode, IntraPredModeC is assigned to IntraPredModeC, and the flag is luminance. If the mode is different from the mode, planar prediction (0), DC prediction (1), direction prediction (2 to 34), and LM mode (35) may be decoded as IntraPredModeC.
  • the loop filter 305 applies filters such as a deblocking filter, a sample adaptive offset (SAO), and an adaptive loop filter (ALF) to the decoded image of the CU generated by the adding unit 312.
  • filters such as a deblocking filter, a sample adaptive offset (SAO), and an adaptive loop filter (ALF) to the decoded image of the CU generated by the adding unit 312.
  • the reference picture memory 306 stores the decoded image of the CU generated by the adding unit 312 at a predetermined position for each decoding target picture and CU.
  • the prediction parameter memory 307 stores the prediction parameter in a predetermined position for each decoding target picture and prediction unit (or sub-block, fixed-size block, pixel). Specifically, the prediction parameter memory 307 stores the inter prediction parameter decoded by the inter prediction parameter decoding unit 303, the intra prediction parameter decoded by the intra prediction parameter decoding unit 304, and the prediction mode predMode separated by the entropy decoding unit 301. .
  • the stored inter prediction parameters include, for example, a prediction list utilization flag predFlagLX (inter prediction identifier inter_pred_idc), a reference picture index refIdxLX, and a motion vector mvLX.
  • the prediction image generation unit 308 receives the prediction mode predMode input from the entropy decoding unit 301 and the prediction parameter from the prediction parameter decoding unit 302. Further, the predicted image generation unit 308 reads a reference picture from the reference picture memory 306. The prediction image generation unit 308 generates a prediction image of the PU using the input prediction parameter and the read reference picture in the prediction mode indicated by the prediction mode predMode.
  • the inter prediction image generation unit 309 uses the inter prediction parameter input from the inter prediction parameter decoding unit 303 and the read reference picture to perform prediction of the PU by inter prediction. Is generated.
  • the inter prediction image generation unit 309 performs a motion vector on the basis of the decoding target PU from the reference picture indicated by the reference picture index refIdxLX for a reference picture list (L0 list or L1 list) having a prediction list use flag predFlagLX of 1.
  • the reference picture block at the position indicated by mvLX is read from the reference picture memory 306.
  • the inter prediction image generation unit 309 performs prediction based on the read reference picture block to generate a prediction image of the PU.
  • the inter prediction image generation unit 309 outputs the generated prediction image of the PU to the addition unit 312.
  • the intra predicted image generation unit 310 When the prediction mode predMode indicates the intra prediction mode, the intra predicted image generation unit 310 performs intra prediction using the intra prediction parameter input from the intra prediction parameter decoding unit 304 and the read reference picture. Specifically, the intra predicted image generation unit 310 reads, from the reference picture memory 306, neighboring PUs that are pictures to be decoded and are in a predetermined range from the decoding target PUs among the PUs that have already been decoded.
  • the predetermined range is, for example, one of the left, upper left, upper, and upper right adjacent PUs when the decoding target PU sequentially moves in the so-called raster scan order, and differs depending on the intra prediction mode.
  • the raster scan order is an order in which each row is sequentially moved from the left end to the right end in each picture from the upper end to the lower end.
  • the intra predicted image generation unit 310 performs prediction in the prediction mode indicated by the intra prediction mode IntraPredMode for the read adjacent PU, and generates a predicted image of the PU.
  • the intra predicted image generation unit 310 outputs the generated predicted image of the PU to the adding unit 312.
  • the intra prediction image generation unit 310 performs planar prediction (0), DC prediction (1), direction according to the luminance prediction mode IntraPredModeY.
  • Prediction image of luminance PU is generated by any of prediction (2 to 34), and planar prediction (0), DC prediction (1), direction prediction (2 to 34), LM mode according to color difference prediction mode IntraPredModeC
  • a predicted image of the color difference PU is generated by any of (35).
  • the inverse quantization / inverse DCT unit 311 inversely quantizes the quantization coefficient input from the entropy decoding unit 301 to obtain a DCT coefficient.
  • the inverse quantization / inverse DCT unit 311 performs inverse DCT (InverseDiscrete Cosine Transform) on the obtained DCT coefficient to calculate a residual signal.
  • the inverse quantization / inverse DCT unit 311 outputs the calculated residual signal to the addition unit 312.
  • the addition unit 312 adds the prediction image of the PU input from the inter prediction image generation unit 309 or the intra prediction image generation unit 310 and the residual signal input from the inverse quantization / inverse DCT unit 311 for each pixel, Generate a decoded PU image.
  • the adding unit 312 stores the generated decoded image of the PU in the reference picture memory 306, and outputs a decoded image Td in which the generated decoded image of the PU is integrated for each picture to the outside.
  • FIG. 12 is a schematic diagram illustrating a configuration of the inter prediction parameter decoding unit 303 according to the present embodiment.
  • the inter prediction parameter decoding unit 303 includes an inter prediction parameter decoding control unit 3031, an AMVP prediction parameter derivation unit 3032, an addition unit 3035, a merge prediction parameter derivation unit (merge processing unit) 3036, a sub-block prediction parameter derivation unit 3037, and a BTM process. A portion 3038 is included.
  • the inter prediction parameter decoding control unit 3031 instructs the entropy decoding unit 301 to decode a code (syntax element) related to inter prediction, and a code (syntax element) included in the encoded data, for example, PU partition mode part_mode , Merge flag merge_flag, merge index merge_idx, inter prediction identifier inter_pred_idc, reference picture index refIdxLX, prediction vector index mvp_LX_idx, and difference vector mvdLX are extracted.
  • the inter prediction parameter decoding control unit 3031 first extracts a merge flag merge_flag.
  • the inter prediction parameter decoding control unit 3031 expresses that a certain syntax element is to be extracted, it means that the entropy decoding unit 301 is instructed to decode a certain syntax element, and the corresponding syntax element is read from the encoded data. To do.
  • the inter prediction parameter decoding control unit 3031 uses the entropy decoding unit 301 to extract the AMVP prediction parameter from the encoded data.
  • AMVP prediction parameters include an inter prediction identifier inter_pred_idc, a reference picture index refIdxLX, a prediction vector index mvp_LX_idx, and a difference vector mvdLX.
  • the AMVP prediction parameter derivation unit 3032 derives a prediction vector mvpLX from the prediction vector index mvp_LX_idx. Details will be described later.
  • the inter prediction parameter decoding control unit 3031 outputs the difference vector mvdLX to the addition unit 3035.
  • the adding unit 3035 adds the prediction vector mvpLX and the difference vector mvdLX to derive a motion vector.
  • the inter prediction parameter decoding control unit 3031 extracts the merge index merge_idx as a prediction parameter related to merge prediction.
  • the inter prediction parameter decoding control unit 3031 outputs the extracted merge index merge_idx to the merge prediction parameter derivation unit 3036 (details will be described later), and outputs the sub-block prediction mode flag subPbMotionFlag to the sub-block prediction parameter derivation unit 3037.
  • the subblock prediction parameter deriving unit 3037 divides the PU into a plurality of subblocks according to the value of the subblock prediction mode flag subPbMotionFlag, and derives a motion vector in units of subblocks.
  • the prediction block is predicted in units of blocks as small as 4x4 or 8x8.
  • a sub-block prediction mode is used for a method in which a CU is divided into a plurality of partitions (PUs such as 2NxN, Nx2N, and NxN) and the syntax of prediction parameters is encoded in units of partitions. Since a plurality of sub-blocks are grouped into a set and the syntax of the prediction parameter is encoded for each set, motion information of a large number of sub-blocks can be encoded with a small amount of code.
  • the sub-block prediction parameter derivation unit 3037 performs sub-block prediction in the sub-block prediction mode, and performs a spatio-temporal sub-block prediction unit 30371, an affine prediction unit 30372, a matching prediction unit (first motion vector search unit) , A second motion vector search unit) 30373.
  • the matching prediction unit 30373 may not be configured as an element of the sub-block prediction parameter derivation unit 3037, but may be configured as an element of the merge prediction parameter derivation unit 3036.
  • Subblock prediction mode flag a method for deriving a sub-block prediction mode flag subPbMotionFlag indicating whether or not a prediction mode of a certain PU is a sub-block prediction mode in the image encoding device 11 (details will be described later) will be described.
  • the image encoding device 11 derives a sub-block prediction mode flag subPbMotionFlag based on which one of spatial sub-block prediction SSUB, temporal sub-block prediction TSUB, affine prediction AFFINE, and matching prediction MAT described later is used. For example, when the prediction mode selected by a certain PU is N (for example, N is a label indicating the selected merge candidate), the sub-block prediction mode flag subPbMotionFlag may be derived by the following equation.
  • the above equation may be appropriately changed according to the type of sub-block prediction mode performed by the image encoding device 11. That is, when the image encoding device 11 is configured to perform spatial subblock prediction SSUB and affine prediction AFFINE, the subblock prediction mode flag subPbMotionFlag may be derived as follows.
  • subPbMotionFlag is included in the prediction mode processing corresponding to each subblock prediction. May be set to 1.
  • the sub-block prediction mode subPbMotionFlag may be derived as follows.
  • means that subPbMotionFlag may be derived by a sum operation (OR) with another condition. That is, subPbMotionFlag may be derived by the sum operation of determination of prediction mode N and small PU size determination as follows (the same applies hereinafter).
  • CU size is 8x8
  • the division type is NxN
  • subPbMotionFlag may be derived as follows.
  • a case where the PU width or height is 4 may be included as a case of determining sub-block prediction. That is, the sub-block prediction mode flag subPbMotionFlag may be derived as follows.
  • the sub-block prediction parameter deriving unit 3037 of the image decoding device 31 derives a sub-block prediction mode from the subPbMotionFlag by a method reverse to that described above.
  • the spatio-temporal sub-block prediction unit 30371 calculates the target PU from the motion vector of the PU on the reference image temporally adjacent to the target PU (for example, the immediately preceding picture) or the motion vector of the PU spatially adjacent to the target PU.
  • the motion vector of the sub-block obtained by dividing is derived.
  • (xPb, yPb) is the upper left coordinate of the target PU
  • nPbW, nPbH are the size of the target PU
  • nSbW, nSbH are the sizes of the sub-blocks.
  • the above-described temporal sub-block prediction candidate TSUB and spatial sub-block prediction candidate SSUB are selected as one mode (merge candidate) of the merge mode.
  • the affine prediction unit 30372 derives the affine prediction parameters of the target PU.
  • motion vectors (mv0_x, mv0_y) (mv1_x, mv1_y) of two control points (V0, V1) of the target PU are derived as affine prediction parameters.
  • the motion vector of each control point may be derived by prediction from the motion vector of the adjacent PU of the target PU, and further, the prediction vector and the encoded data derived as the motion vector of the control point
  • the motion vector of each control point may be derived from the sum of the difference vectors derived from.
  • FIG. 13 shows an example of deriving the motion vector spMvLX of each sub-block constituting the target PU (nPbW ⁇ nPbH) from the motion vector (mv0_x, mv0_y) of the control point V0 and the motion vector (mv1_x, mv1_y) of V1.
  • the motion vector spMvLX of each subblock is derived as a motion vector for each point located at the center of each subblock, as shown in FIG.
  • xPb and yPb are the upper left coordinates of the target PU
  • nPbW and nPbH are the width and height of the target PU
  • nSbW and nSbH are the width and height of the sub-block.
  • the matching prediction unit 30373 derives a motion vector spMvLX of a sub-block constituting the PU by performing a matching process of either bilateral matching (Bilateralmatching, BM) or template matching (Templatematching, TM).
  • FIG. 14 is a diagram for explaining (a) bilateral matching and (b) template matching.
  • the matching prediction mode is selected as one merge candidate (matching candidate) in the merge mode.
  • the matching prediction unit 30373 derives a motion vector by matching regions (comparison of proximity of regions, derivation of differences) on a plurality of reference images, assuming that the object moves at a constant velocity.
  • Bilateral matching is a matching between reference images A and B, assuming that an object passes through a certain region of reference image A, a target PU of target picture Cur_Pic, and a certain region of reference image B with a uniform motion.
  • a motion vector is derived by matching an adjacent area Temp_Cur of the target PU with an adjacent area Temp_LX of the reference block on the reference picture, assuming that the adjacent vector of the target PU and the motion vector of the target PU are equal.
  • (MV0_x, MV0_y) is determined so that the matching cost between Block_A and Block_B is minimized.
  • the (MV0_x, MV0_y) derived in this way is a motion vector assigned to the sub-block.
  • (b) of FIG. 14 is a figure for demonstrating template matching (Templatematching) among the said matching processes.
  • one reference picture is referred to in order to derive a motion vector of the sub-block Cur_block in the target picture Cur_Pic.
  • the reference block Block_A having the upper left coordinates (xPos, yPos) specified by is specified.
  • (xCur, yCur) is the upper left coordinate of the sub-block Cur_block.
  • a template region Temp_Cur (template) adjacent to the sub-block Cur_block in the target picture Cur_Pic and a template region Temp_L0 adjacent to Block_A in the reference picture A are set.
  • the template region Temp_Cur is composed of a region adjacent to the upper side of the sub-block Cur_block and a region adjacent to the left side of the sub-block Cur_block.
  • the template area Temp_L0 is composed of an area adjacent to the upper side of Block_A and an area adjacent to the left side of Block_A.
  • the template plays a role of a teacher image (teacher block) in matching (comparison between images).
  • a candidate block pointed to by a motion vector candidate is compared with a template that is a teacher, and a motion vector candidate pointing to a candidate block closest to the teacher is derived as a motion vector.
  • FIG. 7 is a schematic diagram illustrating the configuration of the merge prediction parameter deriving unit 3036 according to the present embodiment.
  • the merge prediction parameter derivation unit 3036 includes a merge candidate derivation unit 30361, a merge candidate selection unit 30362, and a merge candidate storage unit 30363.
  • the merge candidate storage unit 30363 stores the merge candidates input from the merge candidate derivation unit 30361.
  • the merge candidate includes a prediction list use flag predFlagLX, a motion vector mvLX, and a reference picture index refIdxLX.
  • an index is assigned to the stored merge candidate according to a predetermined rule.
  • the merge candidate derivation unit 30361 derives a merge candidate using the motion vector of the adjacent PU that has already been decoded and the reference picture index refIdxLX as they are.
  • merge candidates may be derived using affine prediction. This method is described in detail below.
  • the merge candidate derivation unit 30361 may use affine prediction for a spatial merge candidate derivation process, a temporal merge candidate derivation process, a combined merge candidate derivation process, and a zero merge candidate derivation process described later. Affine prediction is performed in units of sub-blocks, and prediction parameters are stored in the prediction parameter memory 307 for each sub-block. Alternatively, the affine prediction may be performed on a pixel basis.
  • the merge candidate derivation unit 30361 reads and reads the prediction parameters (prediction list use flag predFlagLX, motion vector mvLX, reference picture index refIdxLX) stored in the prediction parameter memory 307 according to a predetermined rule.
  • the predicted parameters are derived as merge candidates.
  • the prediction parameter to be read is a prediction parameter related to each of the PUs within a predetermined range from the decoding target PU (for example, all or part of the PUs in contact with the lower left end, the upper left end, and the upper right end of the decoding target PU, respectively). is there.
  • the merge candidates derived by the merge candidate deriving unit 30361 are stored in the merge candidate storage unit 30363.
  • the merge candidate derivation unit 30361 reads the prediction parameter of the PU in the reference image including the lower right coordinate of the decoding target PU from the prediction parameter memory 307 and sets it as a merge candidate.
  • the reference picture designation method may be, for example, the reference picture index refIdxLX designated in the slice header, or may be designated using the smallest reference picture index refIdxLX of the PU adjacent to the decoding target PU.
  • the merge candidates derived by the merge candidate deriving unit 30361 are stored in the merge candidate storage unit 30363.
  • the merge candidate derivation unit 30361 uses two different derived merge candidate motion vectors and reference picture indexes already derived and stored in the merge candidate storage unit 30363 as the motion vectors of L0 and L1, respectively. Combined merge candidates are derived by combining them. The merge candidates derived by the merge candidate deriving unit 30361 are stored in the merge candidate storage unit 30363.
  • the merge candidate derivation unit 30361 derives a merge candidate in which the reference picture index refIdxLX is 0 and both the X component and the Y component of the motion vector mvLX are 0.
  • the merge candidates derived by the merge candidate deriving unit 30361 are stored in the merge candidate storage unit 30363.
  • the merge candidate selection unit 30362 selects, from the merge candidates stored in the merge candidate storage unit 30363, a merge candidate to which an index corresponding to the merge index merge_idx input from the inter prediction parameter decoding control unit 3031 is assigned. As an inter prediction parameter.
  • the merge candidate selection unit 30362 stores the selected merge candidate in the prediction parameter memory 307 and outputs it to the prediction image generation unit 308.
  • FIG. 8 is a schematic diagram showing the configuration of the AMVP prediction parameter derivation unit 3032 according to this embodiment.
  • the AMVP prediction parameter derivation unit 3032 includes a vector candidate derivation unit 3033, a vector candidate selection unit 3034, and a vector candidate storage unit 3039.
  • the vector candidate derivation unit 3033 reads the already processed PU motion vector mvLX stored in the prediction parameter memory 307 based on the reference picture index refIdx, derives a prediction vector candidate, and sends the prediction vector candidate to the vector candidate storage unit 3039. Store in candidate list mvpListLX [].
  • the vector candidate selection unit 3034 selects the motion vector mvpListLX [mvp_LX_idx] indicated by the prediction vector index mvp_LX_idx from the prediction vector candidates in the prediction vector candidate list mvpListLX [] as the prediction vector mvpLX.
  • the vector candidate selection unit 3034 outputs the selected prediction vector mvpLX to the addition unit 3035.
  • a prediction vector candidate is a PU for which decoding processing has been completed, and is derived by scaling a motion vector of a PU (for example, an adjacent PU) within a predetermined range from the decoding target PU.
  • the adjacent PU includes a PU that is spatially adjacent to the decoding target PU, for example, the left PU and the upper PU, and an area that is temporally adjacent to the decoding target PU, for example, the same position as the decoding target PU. It includes areas obtained from prediction parameters of PUs with different times.
  • the addition unit 3035 adds the prediction vector mvpLX input from the AMVP prediction parameter derivation unit 3032 and the difference vector mvdLX input from the inter prediction parameter decoding control unit 3031 to calculate a motion vector mvLX.
  • the adding unit 3035 outputs the calculated motion vector mvLX to the predicted image generation unit 308 and the prediction parameter memory 307.
  • the motion vector derived by the merge prediction parameter deriving unit 3036 or the motion vector derived by the matching prediction unit 30373 is not directly output to the inter prediction image generation unit 309 but is output via the BTM processing unit 3038. May be.
  • the BTM processing unit 3038 uses the prediction image generated by using the motion vector derived by the merge prediction parameter deriving unit 3036 or the matching prediction unit 30373 as a template, and executes bilateral template matching (BTM) processing. A highly accurate motion vector is derived. Details of the BTM processing will be described later.
  • BTM bilateral template matching
  • FIG. 11 is a schematic diagram illustrating a configuration of an inter predicted image generation unit 309 included in the predicted image generation unit 308 according to the present embodiment.
  • the inter prediction image generation unit 309 includes a motion compensation unit (prediction image generation device) 3091 and a weight prediction unit 3094.
  • the motion compensation unit 3091 receives the reference picture index refIdxLX from the reference picture memory 306 based on the inter prediction parameters (prediction list use flag predFlagLX, reference picture index refIdxLX, motion vector mvLX) input from the inter prediction parameter decoding unit 303.
  • an interpolation image motion compensation image
  • a motion compensation image is generated by reading out a block at a position shifted by the motion vector mvLX starting from the position of the decoding target PU.
  • a motion compensation image is generated by applying a filter for generating a pixel at a decimal position called a motion compensation filter.
  • the weight prediction unit 3094 generates a prediction image of the PU by multiplying the input motion compensation image predSamplesLX by a weight coefficient.
  • the input motion compensated image predSamplesLX (LX is L0 or L1) is represented by the number of pixel bits The following equation is processed to match
  • predSamples [X] [Y] Clip3 (0, (1 ⁇ bitDepth)-1, (predSamplesLX [X] [Y] + offset1) >> shift1)
  • shift1 14 ⁇ bitDepth
  • offset1 1 ⁇ (shift1-1).
  • predSamples [X] [Y] Clip3 (0, (1 ⁇ bitDepth)-1, (predSamplesL0 [X] [Y] + predSamplesL1 [X] [Y] + offset2) >> shift2)
  • shift2 15-bitDepth
  • offset2 1 ⁇ (shift2-1).
  • the weight prediction unit 3094 when performing weight prediction, derives the weight prediction coefficient w0 and the offset o0 from the encoded data, and performs the processing of the following equation.
  • predSamples [X] [Y] Clip3 (0, (1 ⁇ bitDepth)-1, ((predSamplesLX [X] [Y] * w0 + 2 ⁇ (log2WD-1)) >> log2WD) + o0)
  • log2WD is a variable indicating a predetermined shift amount.
  • the weight prediction unit 3094 when performing weight prediction, derives weight prediction coefficients w0, w1, o0, o1 from the encoded data, and performs the processing of the following equation.
  • predSamples [X] [Y] Clip3 (0, (1 ⁇ bitDepth)-1, (predSamplesL0 [X] [Y] * w0 + predSamplesL1 [X] [Y] * w1 + ((o0 + o1 + 1) ⁇ log2WD)) >> (log2WD + 1)) ⁇ Motion vector decoding process> Below, with reference to FIG. 9, the motion vector decoding process which concerns on this embodiment is demonstrated concretely.
  • the motion vector decoding process includes a process of decoding syntax elements related to inter prediction (also referred to as motion syntax decoding process) and a process of deriving a motion vector ( Motion vector derivation process).
  • FIG. 9 is a flowchart illustrating a flow of inter prediction syntax decoding processing performed by the inter prediction parameter decoding control unit 3031. In the following description of FIG. 9, each process is performed by the inter prediction parameter decoding control unit 3031 unless otherwise specified.
  • merge_flag! 0 is true (Y in S102)
  • merge index merge_idx is decoded in S103, and the motion vector derivation process (S111) in the merge mode is executed.
  • inter_pred_idc is other than PRED_L1 (PRED_L0 or PRED_BI)
  • the reference picture index refIdxL0, the difference vector parameter mvdL0, and the prediction vector index mvp_L0_idx are decoded in S105, S106, and S107, respectively.
  • inter_pred_idc is other than PRED_L0 (PRED_L1 or PRED_BI)
  • the reference picture index refIdxL1 is decoded in S108, S109, and S110.
  • a motion vector derivation process (S112) in the AMVP mode is executed.
  • FIG. 15 is a flowchart showing an outline of the motion prediction mode determination flow.
  • the motion prediction mode determination flow is executed by the inter prediction parameter decoding unit 303.
  • the motion prediction mode is a mode for determining a method for deriving a motion vector used for motion compensation prediction.
  • mvLX pmvCand [mvp_LX_idx] + mvdLX
  • TM template matching
  • S1404b template matching
  • BM bilateral matching
  • step S1404 when the fruc_mode_idx is MODE_BM (for example, 1), the pattern prediction vector is derived by bilateral matching when the fruc_mode_idx is MODE_BM (for example, 1), and when the fruc_mode_idx is MODE_TM (for example 2), the pattern matching vector is derived by template matching.
  • the fruc_mode_idx is MODE_BM (for example, 1)
  • the pattern matching vector is derived by template matching.
  • the BTM processing unit 3038 determines whether or not to perform bilateral template matching (BTM) processing (S1413), and determines that BTM processing is performed (YES in S1413). , BTM processing is executed (S1414).
  • BTM bilateral template matching
  • Whether or not to perform BTM processing is determined to perform BTM processing if a motion vector is derived by bi-directional prediction in the merge mode, and is determined not to perform BTM processing unless bi-directional prediction is performed. .
  • the BTM process is not performed even in bidirectional prediction.
  • FIG. 16A is a diagram showing a relationship between a reference image and a template in BTM processing
  • FIG. 16B is a diagram showing a processing flow.
  • FIG. 17 is a diagram for explaining the details of the template in the BTM processing.
  • FIG. 18 is a diagram for explaining a local search in BTM processing (search for a motion vector in a local region near a certain initial vector). In the following, when searching for a local vector centered on an initial vector, the initial vector does not necessarily have to be completely centered in the search space. That is, you may search for some directions largely.
  • the BTM processing unit 3038 first generates a prediction block from a plurality of motion vectors (for example, mvL0 and mvL1) derived by the merge prediction parameter deriving unit 3036.
  • the predicted block of the Cur block is assumed to be a template (hereinafter simply referred to as a predicted block by the Cur block).
  • the motion compensation image predSamplesL0 derived from mvL0 and the weight prediction image predSamples [] [] derived from the motion compensation image predSamplesL1 derived from mvL1 are predicted blocks.
  • predSamples [X] [Y] Clip3 (0, (1 ⁇ bitDepth)-1, (predSamplesL0 [X] [Y] + predSamplesL1 [X] [Y] + offset2) >> shift2)
  • the BTM processing unit 3038 sets motion vector candidates in a range centered on mvL0 or mvL1 (initial vector), and matches the predicted image in the motion vector candidate with the template. Deriving the cost. Then, the motion vector is updated to the vectors mvL0 ′ and mvL1 ′ that minimize the matching cost.
  • the BTM processing unit 3038 first acquires a template (S501).
  • the template is acquired by generating a prediction block from a plurality of motion vectors (for example, mvL0 and mvL1) derived by the merge prediction parameter deriving unit 3036 and using the prediction block as a template.
  • the BTM processing unit 3038 performs a local search (S502). As shown in FIG. 16B, the local search may be performed by repeating a plurality of different accuracy searches.
  • the local search is performed in the order of M pixel accuracy search L0 processing (S511), N pixel accuracy search L0 processing (S512), M pixel accuracy search L1 processing (S513), and N pixel accuracy search L1 processing (S514).
  • M and N need only have a higher accuracy of N than M.
  • the M pixel accuracy search L0 process performs a search process centered on the coordinates indicated by mvL0.
  • the N pixel accuracy search L0 process performs a search process centered on the coordinates where the matching cost is minimized in the M pixel accuracy search L0 process.
  • the M pixel accuracy search L1 process performs a search process centered on the coordinates indicated by mvL1. Then, the N pixel accuracy search L1 process performs a search process centered on the coordinates at which the matching cost is minimized in the M pixel accuracy search L1 process.
  • searchOffsetSquare [8] ⁇ (-1,1) , (0,1), (1,1), (1,0), (1, -1), (0, -1), (-1, -1), (-1,0) ⁇ 8 points to be searched are searched for.
  • searchOffsetSquare [8] ⁇ (-1,1) , (0,1), (1,1), (1,0), (1, -1), (0, -1), (-1, -1), (-1,0) ⁇ 8 points to be searched are searched for.
  • the starting point of the initial vector startMV is indicated by a white diamond
  • the search candidate point is indicated by a black circle
  • the end point of the optimal vector bestMV is indicated by a square.
  • the optimal vector bestMV is a point that evaluates the matching cost with each search target and becomes the search target with the lowest matching cost.
  • the BTM processing unit 3038 searches for 8 points at a distance of 1/2 pixel using the point selected as the end point of the optimal vector bestMV in the one-pixel accuracy search as the starting point of the initial vector startMV in this search. , Evaluate matching costs.
  • the eight points to be searched are the same as the positional relationship between the initial vector startMV and the search candidate point in the one-image accuracy search, and the distance is only 1 ⁇ 2 pixel.
  • FIGS. 19A and 19B are diagrams showing an outline of template matching.
  • L0 matching processing S801 and L1 matching processing (S802) are performed.
  • S811, S821) and S812, S822 are performed. Details of the block search and sub-block search will be described later.
  • FIG. 20A and 20B are diagrams showing an outline of bilateral matching.
  • L0 / L1 matching processing S901
  • S91 block search
  • S912 sub-block search
  • FIG. 21 is a flowchart showing the flow of motion vector derivation processing in the matching mode (template matching, bilateral matching).
  • FIG. 22 is a diagram for explaining the motion vector deriving process in the matching mode.
  • the processing shown in FIG. 21 is executed by the matching prediction unit 30373.
  • steps S1051 to S1054 are block searches executed at the block level. That is, a motion vector is derived for the entire block (CU or PU) using pattern matching. Specifically, as shown in FIG. 22A, motion vectors in the entire target block are derived. In other words, a motion vector is derived for each target block.
  • steps S1055 to S1060 are a sub-block search executed at the sub-block level. That is, using a pattern match, a motion vector is derived for each sub-block constituting the block. In particular. As shown in FIG. 22B, a motion vector is derived for each sub-block in the target block. Note that the size of the sub-block is 1/8 both vertically and horizontally with respect to the target block. However, the minimum size of the sub-block is 4 ⁇ 4 pixels.
  • FRUC_MODE is a variable indicating the type of matching mode, and corresponds to the fruc_mode_idx already described.
  • step S1053 a block-level initial vector in the target block is derived (initial vector search).
  • the initial vector is a motion vector that serves as a base for the search.
  • a limited motion vector candidate spatial merge candidate, temporal merge candidate, combined merge candidate, zero vector, ATMVP vector of the target block, etc.
  • the vector that minimizes is derived as the initial vector.
  • the initial vector candidate is a motion vector derived based on the motion vector of the processed reference point.
  • the ATMVP vector is a vector derived from the average (or weighted average, median) of the motion vector around the target block and the motion vector of the reference image.
  • the initial vector search does not include a step search that repeats the search recursively according to the searched result and a raster search that searches a continuous region. These searches are called local searches.
  • step S1054 a block level local search (local search) in the target block is performed.
  • a local region centered on the initial vector derived in step S1051 is further searched to search for a vector having a minimum matching cost, and set as a final vector.
  • the local search may be a step search, raster search, or spiral search. Details of the local search will be described later.
  • an initial vector of a sub-block in the target block is derived (initial vector search).
  • vector candidates target block selection vector, zero vector, center collocation vector of the subblock, lower right collocation vector of the subblock, ATMVP vector of the subblock, upper adjacent vector of the subblock, the sub
  • the vector having the smallest matching cost among the left adjacent vectors of the block is set as the initial vector of the sub-block.
  • the vector candidates used for the initial vector search of the sub-block are not limited to the above-described vectors.
  • step S1059 a local search centering on the initial vector of the sub-block selected in S1058 is performed. Then, the matching cost of vector candidates near the initial vector of the sub-block is derived, and the minimum vector is derived as the sub-block motion vector.
  • FIG. 4 is a block diagram illustrating a configuration of the image encoding device 11 according to the present embodiment.
  • the image encoding device 11 includes a prediction image generation unit 101, a subtraction unit 102, a DCT / quantization unit 103, an entropy encoding unit 104, an inverse quantization / inverse DCT unit 105, an addition unit 106, a loop filter 107, and a prediction parameter memory.
  • the prediction parameter encoding unit 111 includes an inter prediction parameter encoding unit (motion vector generation device) 112 and an intra prediction parameter encoding unit 113.
  • the predicted image generation unit 101 generates, for each picture of the image T, a predicted image P of the prediction unit PU for each encoding unit CU that is an area obtained by dividing the picture.
  • the predicted image generation unit 101 reads a decoded block from the reference picture memory 109 based on the prediction parameter input from the prediction parameter encoding unit 111.
  • the prediction parameter input from the prediction parameter encoding unit 111 is, for example, a motion vector in the case of inter prediction.
  • the predicted image generation unit 101 reads a block at a position on the reference image indicated by the motion vector with the target PU as a starting point.
  • the prediction parameter is, for example, an intra prediction mode.
  • a pixel value of an adjacent PU used in the intra prediction mode is read from the reference picture memory 109, and a predicted image P of the PU is generated.
  • the predicted image generation unit 101 generates a predicted image P of the PU using one prediction method among a plurality of prediction methods for the read reference picture block.
  • the predicted image generation unit 101 outputs the generated predicted image P of the PU to the subtraction unit 102.
  • FIG. 6 is a schematic diagram illustrating a configuration of an inter predicted image generation unit 1011 included in the predicted image generation unit 101.
  • the inter prediction image generation unit 1011 includes a motion compensation unit 10111 and a weight prediction unit 10112. Since the motion compensation unit 10111 and the weight prediction unit 10112 have the same configurations as the motion compensation unit 3091 and the weight prediction unit 3094 described above, description thereof is omitted here.
  • the prediction image generation unit 101 generates a prediction image P of the PU based on the pixel value of the reference block read from the reference picture memory, using the parameter input from the prediction parameter encoding unit.
  • the predicted image generated by the predicted image generation unit 101 is output to the subtraction unit 102 and the addition unit 106.
  • the subtraction unit 102 subtracts the signal value of the predicted image P of the PU input from the predicted image generation unit 101 from the pixel value of the corresponding PU of the image T, and generates a residual signal.
  • the subtraction unit 102 outputs the generated residual signal to the DCT / quantization unit 103.
  • the DCT / quantization unit 103 performs DCT on the residual signal input from the subtraction unit 102 and calculates a DCT coefficient.
  • the DCT / quantization unit 103 quantizes the calculated DCT coefficient to obtain a quantization coefficient.
  • the DCT / quantization unit 103 outputs the obtained quantization coefficient to the entropy coding unit 104 and the inverse quantization / inverse DCT unit 105.
  • the entropy encoding unit 104 receives the quantization coefficient from the DCT / quantization unit 103 and receives the encoding parameter from the prediction parameter encoding unit 111.
  • Examples of input encoding parameters include codes such as a reference picture index refIdxLX, a prediction vector index mvp_LX_idx, a difference vector mvdLX, a prediction mode predMode, and a merge index merge_idx.
  • the entropy encoding unit 104 generates an encoded stream Te by entropy encoding the input quantization coefficient and encoding parameter, and outputs the generated encoded stream Te to the outside.
  • the inverse quantization / inverse DCT unit 105 inversely quantizes the quantization coefficient input from the DCT / quantization unit 103 to obtain a DCT coefficient.
  • the inverse quantization / inverse DCT unit 105 performs inverse DCT on the obtained DCT coefficient to calculate a residual signal.
  • the inverse quantization / inverse DCT unit 105 outputs the calculated residual signal to the addition unit 106.
  • the addition unit 106 adds the signal value of the prediction image P of the PU input from the prediction image generation unit 101 and the signal value of the residual signal input from the inverse quantization / inverse DCT unit 105 for each pixel, and performs decoding. Generate an image.
  • the adding unit 106 stores the generated decoded image in the reference picture memory 109.
  • the loop filter 107 performs a deblocking filter, a sample adaptive offset (SAO), and an adaptive loop filter (ALF) on the decoded image generated by the adding unit 106.
  • SAO sample adaptive offset
  • ALF adaptive loop filter
  • the prediction parameter memory 108 stores the prediction parameter generated by the encoding parameter determination unit 110 at a predetermined position for each encoding target picture and CU.
  • the reference picture memory 109 stores the decoded image generated by the loop filter 107 at a predetermined position for each picture to be encoded and each CU.
  • the encoding parameter determination unit 110 selects one set from among a plurality of sets of encoding parameters.
  • the encoding parameter is a parameter to be encoded that is generated in association with the above-described prediction parameter or the prediction parameter.
  • the predicted image generation unit 101 generates a predicted image P of the PU using each of these encoding parameter sets.
  • the encoding parameter determination unit 110 calculates a cost value indicating the amount of information and the encoding error for each of a plurality of sets.
  • the cost value is, for example, the sum of a code amount and a square error multiplied by a coefficient ⁇ .
  • the code amount is the information amount of the encoded stream Te obtained by entropy encoding the quantization error and the encoding parameter.
  • the square error is the sum between pixels regarding the square value of the residual value of the residual signal calculated by the subtracting unit 102.
  • the coefficient ⁇ is a real number larger than a preset zero.
  • the encoding parameter determination unit 110 selects a set of encoding parameters that minimizes the calculated cost value.
  • the entropy encoding unit 104 outputs the selected set of encoding parameters to the outside as the encoded stream Te, and does not output the set of unselected encoding parameters.
  • the encoding parameter determination unit 110 stores the determined encoding parameter in the prediction parameter memory 108.
  • the prediction parameter encoding unit 111 derives a format for encoding from the parameters input from the encoding parameter determination unit 110 and outputs the format to the entropy encoding unit 104. Deriving the format for encoding is, for example, deriving a difference vector from a motion vector and a prediction vector. Also, the prediction parameter encoding unit 111 derives parameters necessary for generating a prediction image from the parameters input from the encoding parameter determination unit 110 and outputs the parameters to the prediction image generation unit 101.
  • the parameter necessary for generating the predicted image is, for example, a motion vector in units of sub-blocks.
  • the inter prediction parameter encoding unit 112 derives an inter prediction parameter such as a difference vector based on the prediction parameter input from the encoding parameter determination unit 110.
  • the inter prediction parameter encoding unit 112 derives parameters necessary for generating a prediction image to be output to the prediction image generating unit 101, and an inter prediction parameter decoding unit 303 (see FIG. 5 and the like) derives inter prediction parameters. Some of the configurations are the same as those to be performed. The configuration of the inter prediction parameter encoding unit 112 will be described later.
  • the intra prediction parameter encoding unit 113 derives a format (for example, MPM_idx, rem_intra_luma_pred_mode) for encoding from the intra prediction mode IntraPredMode input from the encoding parameter determination unit 110.
  • a format for example, MPM_idx, rem_intra_luma_pred_mode
  • the inter prediction parameter encoding unit 112 is a unit corresponding to the inter prediction parameter decoding unit 303 in FIG. 12, and the configuration is shown in FIG.
  • the inter prediction parameter encoding unit 112 includes an inter prediction parameter encoding control unit 1121, an AMVP prediction parameter derivation unit 1122, a subtraction unit 1123, a sub-block prediction parameter derivation unit 1125, and a partition mode derivation unit and a merge flag derivation unit (not shown).
  • An inter prediction identifier deriving unit, a reference picture index deriving unit, a vector difference deriving unit, etc., and a split mode deriving unit, a merge flag deriving unit, an inter prediction identifier deriving unit, a reference picture index deriving unit, and a vector difference deriving unit Respectively derive a PU partition mode part_mode, a merge flag merge_flag, an inter prediction identifier inter_pred_idc, a reference picture index refIdxLX, and a difference vector mvdLX.
  • the inter prediction parameter encoding unit 112 outputs the motion vector (mvLX, subMvLX), the reference picture index refIdxLX, the PU partition mode part_mode, the inter prediction identifier inter_pred_idc, or information indicating these to the prediction image generating unit 101. Also, the inter prediction parameter encoding unit 112 entropy PU partition mode part_mode, merge flag merge_flag, merge index merge_idx, inter prediction identifier inter_pred_idc, reference picture index refIdxLX, prediction vector index mvp_LX_idx, difference vector mvdLX, sub-block prediction mode flag subPbMotionFlag. The data is output to the encoding unit 104.
  • the inter prediction parameter encoding control unit 1121 includes a merge index deriving unit 11211 and a vector candidate index deriving unit 11212.
  • the merge index derivation unit 11211 compares the motion vector and reference picture index input from the encoding parameter determination unit 110 with the motion vector and reference picture index of the merge candidate PU read from the prediction parameter memory 108, and performs merge An index merge_idx is derived and output to the entropy encoding unit 104.
  • a merge candidate is a reference PU (for example, a reference PU that touches the lower left end, upper left end, and upper right end of the encoding target block) within a predetermined range from the encoding target CU to be encoded.
  • the PU has been processed.
  • the vector candidate index deriving unit 11212 derives a prediction vector index mvp_LX_idx.
  • the sub-block prediction parameter derivation unit 1125 includes any one of spatial sub-block prediction, temporal sub-block prediction, affine prediction, and matching prediction according to the value of subPbMotionFlag.
  • a motion vector and a reference picture index for subblock prediction are derived. As described in the description of the image decoding apparatus, the motion vector and the reference picture index are derived by reading out the motion vector and the reference picture index such as the adjacent PU and the reference picture block from the prediction parameter memory 108.
  • the AMVP prediction parameter derivation unit 1122 has the same configuration as the AMVP prediction parameter derivation unit 3032 (see FIG. 12).
  • the motion vector mvLX is input from the encoding parameter determination unit 110 to the AMVP prediction parameter derivation unit 1122.
  • the AMVP prediction parameter derivation unit 1122 derives a prediction vector mvpLX based on the input motion vector mvLX.
  • the AMVP prediction parameter derivation unit 1122 outputs the derived prediction vector mvpLX to the subtraction unit 1123. Note that the reference picture index refIdx and the prediction vector index mvp_LX_idx are output to the entropy encoding unit 104.
  • the subtraction unit 1123 subtracts the prediction vector mvpLX input from the AMVP prediction parameter derivation unit 1122 from the motion vector mvLX input from the coding parameter determination unit 110 to generate a difference vector mvdLX.
  • the difference vector mvdLX is output to the entropy encoding unit 104.
  • the entropy decoding unit 301 the prediction parameter decoding unit 302, the loop filter 305, the predicted image generation unit 308, the inverse quantization / inverse DCT.
  • the prediction parameter encoding unit 111 may be realized by a computer.
  • the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed.
  • the “computer system” is a computer system built in either the image encoding device 11 or the image decoding device 31 and includes hardware such as an OS and peripheral devices.
  • the “computer-readable recording medium” refers to a storage device such as a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a hard disk built in a computer system.
  • the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line,
  • a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain period of time.
  • the program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.
  • the BTM process is executed once after the process in the merge mode. Since the accuracy of the motion vector derived by BTM processing is improved, the accuracy of the predicted image generated from the motion vector is increased, in other words, the difference from the original image is considered to be small. . Therefore, if a predicted image generated from a motion vector derived by BTM processing is used as a new template and BTM processing is executed again, a motion vector with higher accuracy may be derived. Therefore, in this embodiment, the BTM process is executed a plurality of times.
  • FIG. 23 is a flowchart showing the flow of processing in the present embodiment.
  • the BTM processing unit 3038 executes the BTM processing a plurality of times (twice in the example shown in FIG. 23).
  • step S1414a shown in FIG. 23 the same BTM process as that in the first embodiment is executed.
  • step S1414b the predicted image generated using the motion vector derived in step S1414a is used as a template, and the motion vector is derived using the template.
  • Embodiment 2-1 Although the above-described effect is achieved by the method of the second embodiment described above, the processing amount increases as compared to the method of the first embodiment by executing the BTM process a plurality of times. Therefore, in this embodiment, when the M pixel accuracy local search in the BTM process is completed, the template is updated, and the N pixel accuracy local search is executed using the updated template. As a result, the motion vector can be derived using a template closer to the original image while keeping the same number of local searches as the method of the first embodiment.
  • FIG. 24 is a flowchart showing the flow of processing in the present embodiment.
  • the BTM processing unit 3038 performs a local search with M pixel accuracy in step S2301, and then generates in step S2302 using the motion vector derived in step S2301.
  • a local search with N pixel accuracy is performed using the predicted image as a template.
  • the local search order is changed, but the number of times is not changed, so that an increase in processing amount can be suppressed.
  • FIG. 25 is a diagram illustrating a processing flow in the second embodiment and a processing flow in the present embodiment.
  • the processing in the second embodiment is indicated by steps S1414a and S1414b
  • the processing in the present embodiment is indicated by steps S2401 and S2402.
  • steps S1414a and S1414b the processing in the present embodiment.
  • steps S2401 and S2402. As shown in FIG. 25, in the present embodiment, compared with the method of the second embodiment, four of the M pixel accuracy search L0 processing, the N pixel accuracy search L0 processing, the M pixel accuracy search L1 processing, and the N pixel accuracy search L1 processing. Since the processing amount is small for one processing, the overall processing amount can be suppressed.
  • the BTM process is applied to the motion vector derived in the merge mode.
  • BTM processing is applied to the motion vector derived in the matching mode (S1404: FIG. 15).
  • FIG. 26 is a flowchart showing the flow of processing in the matching mode in the present embodiment. As shown in FIG. 26, in the present embodiment, after executing TM processing or BM processing in the matching mode of step S1404 shown in FIG. 15, the BTM processing unit 3038 executes BTM processing only for sub-blocks ( S1404d).
  • the BTM process is executed in addition to the matching mode process, so the processing amount increases. Therefore, in this embodiment, the search accuracy in the process in the matching mode and the search accuracy in the BTM process are set.
  • the matching mode has a 4-pixel accuracy
  • the BTM process has a 1-pixel accuracy
  • a 1 / 2-pixel accuracy As a result, in addition to the processing in the matching mode in the first embodiment, the number of times of matching can be reduced because the search accuracy is coarse compared with the case where the BTM processing is executed, thereby reducing the processing amount. Can be made.
  • the search accuracy is not limited to this, and it is only necessary to execute a coarse search in the matching mode and a fine search in the BTM processing.
  • the matching mode has 4 pixel accuracy
  • the BTM processing has 1 pixel accuracy
  • the matching mode May be 1 pixel accuracy
  • BTM processing may be 1/2 pixel accuracy
  • the matching mode may be 1 pixel accuracy
  • BTM processing may be 1/4 pixel accuracy.
  • processing in the matching mode (TM or BM) is performed at the block level, and BTM processing is performed at the sub-block level.
  • FIG. 27 is a flowchart showing the flow of processing in Processing Example 1.
  • the matching prediction unit 30373 performs only local search at the block level in the TM processing in step S1404b 'or the BM processing in step S1404c'.
  • the BTM processing unit 3038 executes only local search at the sub-block level in the BTM processing in step S1404d.
  • FIG. 28 is a diagram for explaining an example in which a sub-block level template is used in BTM processing.
  • the divided part corresponding to the sub-block in the template corresponding to the target block i.e., the corresponding part of the template whose coordinates in the template are the same as the coordinates of the sub-block in the target block A template used for matching.
  • a motion vector is derived by bilateral template matching.
  • mvL0 and mvL1 are motion vectors derived by block search in TM or BM
  • mvL0 'and mvL1' are motion vectors of the target sub-block.
  • Processing example 2 In Processing Example 2, processing in matching mode (TM, BM) and BTM processing are executed at the block level.
  • FIG. 29 is a flowchart showing the flow of processing in Processing Example 2.
  • the matching prediction unit 30373 performs only a local search at the block level in the TM process in step S1404b 'or the BM process in step S1404c'.
  • the BTM processing unit 3038 executes only a local search at the block level in the BTM processing in step S1404d '.
  • processing at the sub-block level is omitted, so that the processing amount can be reduced. Note that by performing the BTM processing, it is possible to suppress a decrease in accuracy due to not performing a sub-block level local search.
  • Processing example 3 In Processing Example 3, processing in the matching mode (TM, BM) and BTM processing are performed at the block level, and processing in the matching mode (TM, BM) is performed at the sub-block level.
  • FIG. 30 is a flowchart showing the flow of processing in Processing Example 3.
  • the matching prediction unit 30373 performs a local search at the block level in the TM process in step S1404b 'or the BM process in step S1404c'.
  • the BTM processing unit 3038 executes a local search at the block level in the BTM processing in step S1404d '.
  • the matching prediction unit 30373 performs a local search at the sub-block level in the TM process in step S2902 or the BM process in step S2903.
  • initial vector candidates in the matching mode are a spatial merge candidate, a temporal merge candidate, a combined merge candidate, a zero vector, an ATM ATM vector, and the like.
  • the ATMVP vector is a vector derived from the motion vector around the target block and the average (or weighted average, median) of the motion vectors of the reference image.
  • the initial vector is selected from a limited number of candidates, if any of the initial vector candidates does not indicate an appropriate position as the center of the search, the selected initial vector also has poor accuracy. As a result, the accuracy of the motion vector derived from the initial vector is not good.
  • initial vector candidates are added. This increases the number of initial vector candidates, increasing the possibility of selecting an appropriate initial vector and improving the accuracy of the finally derived motion vector.
  • Embodiment 4-1 a motion vector derived by the L0 matching process in template matching (TM) is added to the initial vector candidate selected when bilateral matching (BM) is performed.
  • the motion vector derived by the L0 matching process in template matching is a motion vector derived as a result of the execution of the matching process, and may appropriately indicate the center of the search as an initial vector. Therefore, adding the motion vector derived by the L0 matching process to the initial vector candidate when bilateral matching is performed increases the possibility of selecting an appropriate initial vector, and the accuracy of the finally derived motion vector Can be improved.
  • FIG. 31 is a flowchart showing the flow of processing in this embodiment.
  • the matching prediction unit 30373 first executes part of the template matching process even if it is determined in step S1404a in FIG. Specifically, a template is acquired and a block search for L0 matching processing is executed (S3001). That is, a block level initial vector is selected and a block level local search is performed. Thereafter, the matching prediction unit 30373 starts the bilateral matching process (S1404c), and in the block search in the L0 / L1 matching process (S3002), using the vector candidate obtained by adding the result of the block search executed in step S3001, Perform an initial vector search.
  • a block-level local search is executed using the selected initial vector, and then a sub-block level initial vector is selected to perform a sub-block level local search.
  • the motion vector derived by the L0 matching process in the template matching is added to the initial vector candidate in the bilateral matching.
  • the present invention is not limited to this, and the motion vector derived by the L1 matching process is the initial in the bilateral matching. You may add to a vector candidate.
  • Embodiment 4-2 in template matching or bilateral matching, processing at the block level is the same as that in the first embodiment described above, and the initial vector selection method at the sub-block level is different.
  • template matching or bilateral matching first, a template at the block level is acquired. Next, an initial vector at the block level is selected, and a local search at the block level is performed.
  • the initial vector at the block level is selected.
  • the initial vector candidates include block level motion vector, zero vector, collocated vector (center and lower right), ATMVP vector, additional vector candidate, upper
  • the motion vector of the adjacent sub-block is included. This will be specifically described with reference to FIG. FIG. 32 is a diagram for explaining a sub-block adjacent to the sub-block. 32, the motion vector mvLX in the subblock A or the subblock L adjacent to the subblock X is added to the initial vector candidate in the subblock X.
  • This increases the number of initial vector candidates, increasing the possibility of selecting an appropriate initial vector candidate and improving the accuracy of the finally derived motion vector.
  • the vector with the lowest matching cost is selected as the initial vector.
  • the matching cost of candidate vectors near the sub-block initial vector is derived by local search centering on the initial vector, and the smallest vector is the final motion vector (sub-block level motion vector).
  • the LX (L0 or L1) matching process and the LY (non-LX: L1 or L0) matching process both use the portion adjacent to the upper or left of the target block as a template. .
  • the feature of the lower right portion is not reflected in the template, and there is a possibility that an appropriate motion vector cannot be derived.
  • a predicted image (predicted block) created by the LX matching process is used as a template in the LY matching process.
  • the template used in the LY matching process has the same shape as the target block, and therefore, there is a high possibility that the template reflects the features of the entire block. And the precision of the motion vector to derive can be raised by using the said template.
  • FIG. 33 is a diagram for explaining a template acquisition method according to the present embodiment.
  • FIG. 33A is a diagram illustrating a template acquisition method according to the first embodiment.
  • FIG. 33B is a template acquisition method according to the present embodiment. It is a figure which shows a method.
  • a portion adjacent to the upper or left side of the target block (Cur block) is used as a template.
  • the portion adjacent to the upper or left side of the target block (Cur block) is used as a template as in the first embodiment.
  • the predicted image (prediction block: Pred block) created in this way is used as a template.
  • LX matching process is L0 or L1 may be selected, for example, from Ref0 and Ref1, whichever has a shorter POC distance.
  • Embodiment 6-1 Template matching (TM) performs matching processing in both directions, that is, performs L0 matching processing and L1 matching processing. Therefore, when compared with bilateral matching, the amount of processing increases because bilateral matching involves only one matching process between reference images.
  • TM Template matching
  • the amount of processing is reduced by limiting the matching processing in template matching to one direction.
  • FIG. 34 is a diagram showing a flow of template matching processing in the present embodiment.
  • the matching prediction unit 30373 acquires a template (S3301), and then selects a direction (L0 or L1) for executing the matching process (S3302). Then, a reference image (Ref0 or Ref1) in the selected direction and matching processing (block search, sub-block search) are performed (S3303).
  • the matching process can be limited to one direction, so that the processing amount can be reduced.
  • the direction in which the matching process is executed may be determined by any method. For example, the following four methods are conceivable.
  • Embodiment 6-2 In the image encoding device 11, the inter prediction parameter encoding unit 112 selects whether to use template matching or bilateral matching for matching processing. At this time, in order to select a highly accurate matching method, both template matching and bilateral matching are tried and evaluated. Therefore, the amount of processing is large because the two matching methods are always executed.
  • the matching method is limited according to the shape of the target block. As a result, it is not necessary to always execute the two matching methods, and the amount of processing can be reduced.
  • FIG. 35 is a diagram for explaining the processing for determining the matching mode in the first embodiment, (a) is a table showing the relationship between parameters and matching modes, and (b) is a flowchart showing the flow of processing. Is part of.
  • FIG. 36 is a flowchart showing the flow of processing in this embodiment.
  • fruc_mode_idx for determining the matching mode is composed of 2 bits.
  • fruc_mode_idx is composed of fruc_mode_idx_prefix of the first bit and fruc_mode_idx_suffix of the second bit.
  • the first bit fruc_mode_idx_prefix indicates whether or not the matching mode is set. If “0”, the matching mode is OFF. If “1”, the matching mode is ON.
  • fruc_mode_idx_suffix in the second bit indicates whether the matching method is bilateral matching or template matching. If “0”, bilateral matching is indicated, and if “1”, template matching is indicated. Show. Further, MODE_OFF, MODE_BM, and MODE_TM that can be set in FRUC_MODE correspond to numerical values “0”, “1”, and “2”, respectively.
  • inter prediction parameter decoding control part 3031 performs decoding processing of fruc_mode_idx with the following flows. That is, in the fruc_mode_idx decoding process (S1402), the on / off flag fruc_mode_idx_prefix indicating whether or not to perform the matching mode is first decoded (S3401). If fruc_mode_idx_prefix is “1” (YES in S3402), the process proceeds to step S3403. The flag fruc_mode_idx_suffix indicating the type of matching mode is decoded (S3403). Then, the process proceeds to step S3404. On the other hand, if fruc_mode_idx_prefix is not “1” (NO in S3402), the process directly proceeds to step S3404.
  • the matching mode is determined using the decrypted fruc_mode_idx_prefix and fruc_mode_idx_suffix. Specifically, a value obtained by adding fruc_mode_idx_prefix and fruc_mode_idx_suffix is set in FRUC_MODE (frac_mode_idx). The initial value of fruc_mode_idx_suffix is “0”. When fruc_mode_idx_prefix is “0” indicating that the matching mode is not performed, “0” is set in FRUC_MODE, that is, MODE_OFF corresponding to “0” is set.
  • fruc_mode_idx_prefix is a value “1” indicating that the matching mode is performed
  • type of the matching mode (MODE_BMor MODE_TM) is determined according to fruc_mode_idx_suffix.
  • fruc_mode_idx_prefix is “1” and fruc_mode_idx_suffix is “0”
  • “1” is set in FRUC_MODE, that is, MODE_BM corresponding to “1” is set.
  • the matching method is limited according to the shape of the target block.
  • the shape of the target block is rectangular, only template matching is used, in other words, bilateral matching is prohibited.
  • the inter prediction parameter decoding control unit 3031 performs fruc_mode_idx decoding processing according to the following flow. That is, in the fruc_mode_idx decoding process (S1402), first, fruc_mode_idx_prefix is decoded (S3401), and if fruc_mode_idx_prefix is “1” (YES in S3402), the process proceeds to step S3501, whether the target block is a square, ie, the target It is determined whether the width and height of the block are the same (S3501).
  • step S3403 If the target block is a square (YES in S3501), the process proceeds to step S3403 and fruc_mode_idx_suffix is decoded (S3403). Then, the process proceeds to step S3404. On the other hand, if fruc_mode_idx_prefix is not “1” (NO in S3402), the process directly proceeds to step S3404.
  • step S3404 the matching mode is determined using the decrypted fruc_mode_idx_prefix and fruc_mode_idx_suffix.
  • step S3501 If it is determined in step S3501 that the target block is not square (NO in S3501), the process proceeds to step S3502, and template matching is selected as a matching method (S3502).
  • the matching method is determined by the shape of the target block, it is only necessary to try one matching method on the encoder side (image encoding device 11), and two matching methods are used. The amount of processing is reduced compared to the case of trying. Also, when the shape of the symmetric block is a block shape for which the matching method is limited, the possible value of the flack mode index fruc_mode_idx is also changed from three types to two types of matching or not. Can be reduced.
  • Embodiment 6-3 In the first embodiment described above, the local search at the block level and the sub-block level is performed in the matching process in the matching prediction unit 30373 of the image decoding device 31. If this local search process can be omitted, the amount of processing can be reduced. Therefore, in this embodiment, the processing amount is reduced by omitting some local searches.
  • Example 1 the matching prediction unit 30373 omits the sub-block search and executes only the block search when executing template matching.
  • FIG. 37 is a flowchart showing a process flow of process example 1 in the present embodiment.
  • FIG. 37 shows a flow of processing in matching processing (template matching processing or bilateral matching processing) executed by the matching prediction unit 30373.
  • the block search processing (S1051 to S1054) is the same as that of the first embodiment.
  • the matching prediction unit 30373 determines whether or not the matching method is template matching (S3601). If it is template matching (NO in S3601), the subblock search is not performed and the matching process is performed. finish. On the other hand, if it is not template matching (YES in S3601), the same sub-block search as that of the first embodiment is executed (S1055 to S1060).
  • the sub-block search can be omitted, so that the processing amount can be reduced.
  • the matching prediction unit 30373 when executing bilateral matching, omits both local search for block search and sub-block search, and executes only initial vector search.
  • FIG. 38 is a flowchart showing a process flow of process example 2 in the present embodiment.
  • FIG. 38 shows a flow of processing in matching processing (template matching processing or bilateral matching processing) executed by the matching prediction unit 30373.
  • the matching prediction unit 30373 determines whether or not the matching method is template matching (S3701). If YES in step S3701, the process advances to step S1054 to execute a block-level local search (S1054). On the other hand, if it is not template matching (NO in S3701), the block search ends and proceeds to the sub-block search. That is, if it is bilateral matching, the block level local search is not executed.
  • the matching prediction unit 30373 determines whether or not the matching method is template matching (S3702), and if it is template matching (S3702). In step S1059, the local search at the sub-block level is executed (S1059). On the other hand, if it is not template matching (NO in S3702), the process proceeds to step S1060. That is, if it is bilateral matching, the local search at the sub-block level is not executed.
  • the local search at the block level and the local search at the sub-block level can be omitted, so that the processing amount can be reduced.
  • the matching prediction unit 30373 omits the sub-block level local search regardless of whether template matching or bilateral matching is executed.
  • FIG. 39 is a flowchart showing a process flow of process example 3 in the present embodiment.
  • FIG. 39 shows a flow of processing in matching processing (template matching processing or bilateral matching processing) executed by the matching prediction unit 30373.
  • the block search process (S1051 to S1054) is the same as that of the first embodiment.
  • a sub-block level local search is not executed. That is, after the sub-block level initial vector search in step S1058 is completed, the process proceeds to step S1060. In other words, the local search at the sub-block level in step S1059 in the sub-block search of the first embodiment is not executed.
  • the local search at the sub-block level can be omitted in the template matching and bilateral matching, so that the processing amount can be reduced.
  • Example 4 The present embodiment is a combination of the first embodiment and the third embodiment. Similar to the first embodiment, the matching prediction unit 30373 of the present embodiment does not perform a sub-block search in the case of template matching, and ends the matching process. Also, in the case of bilateral matching, the matching prediction unit 30373 of the present embodiment omits the sub-block level local search as in the third embodiment.
  • FIG. 40 is a flowchart illustrating a process flow of Process Example 4 in the present embodiment.
  • FIG. 40 shows a flow of processing in matching processing (template matching processing or bilateral matching processing) executed by the matching prediction unit 30373.
  • the block search processing (S1051 to S1054) is the same as that of the first embodiment. Then, after the block search ends, the matching prediction unit 30373 determines whether the matching method is not template matching, and if it is template matching, does not perform the sub-block search and ends the matching process. On the other hand, if it is not template matching, only the initial vector search is performed, and the sub-block level local search is not performed. The following processing is performed in the form of bullets.
  • the image coding apparatus 11 may implement
  • LSI Large Scale Integration
  • Each functional block of the image encoding device 11 and the image decoding device 31 may be individually made into a processor, or a part or all of them may be integrated into a processor.
  • the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology may be used.
  • the image encoding device 11 and the image decoding device 31 described above can be used by being mounted on various devices that perform transmission, reception, recording, and reproduction of moving images.
  • the moving image may be a natural moving image captured by a camera or the like, or an artificial moving image (including CG and GUI) generated by a computer or the like.
  • the image encoding device 11 and the image decoding device 31 described above can be used for transmission and reception of moving images.
  • FIG. 41 (a) is a block diagram showing a configuration of a transmission apparatus PROD_A in which the image encoding apparatus 11 is mounted.
  • the transmission apparatus PROD_A modulates a carrier wave with an encoding unit PROD_A1 that obtains encoded data by encoding a moving image, and with the encoded data obtained by the encoding unit PROD_A1.
  • a modulation unit PROD_A2 that obtains a modulation signal and a transmission unit PROD_A3 that transmits the modulation signal obtained by the modulation unit PROD_A2 are provided.
  • the above-described image encoding device 11 is used as the encoding unit PROD_A1.
  • Transmission device PROD_A as a source of moving images to be input to the encoding unit PROD_A1, a camera PROD_A4 that captures moving images, a recording medium PROD_A5 that records moving images, an input terminal PROD_A6 for inputting moving images from the outside, and An image processing unit A7 that generates or processes an image may be further provided.
  • FIG. 41A illustrates a configuration in which the transmission apparatus PROD_A includes all of these, but a part of the configuration may be omitted.
  • the recording medium PROD_A5 may be a recording of a non-encoded moving image, or a recording of a moving image encoded by a recording encoding scheme different from the transmission encoding scheme. It may be a thing. In the latter case, a decoding unit (not shown) for decoding the encoded data read from the recording medium PROD_A5 in accordance with the recording encoding method may be interposed between the recording medium PROD_A5 and the encoding unit PROD_A1.
  • the receiving device PROD_B includes a receiving unit PROD_B1 that receives a modulated signal, a demodulating unit PROD_B2 that obtains encoded data by demodulating the modulated signal received by the receiving unit PROD_B1, and a demodulator A decoding unit PROD_B3 that obtains a moving image by decoding the encoded data obtained by the unit PROD_B2.
  • the above-described image decoding device 31 is used as the decoding unit PROD_B3.
  • the receiving device PROD_B is a display destination PROD_B4 for displaying a moving image, a recording medium PROD_B5 for recording a moving image, and an output terminal for outputting the moving image to the outside as a supply destination of the moving image output by the decoding unit PROD_B3 PROD_B6 may be further provided.
  • FIG. 41B a configuration in which all of these are provided in the receiving device PROD_B is illustrated, but a part may be omitted.
  • the recording medium PROD_B5 may be used for recording a non-encoded moving image, or is encoded using a recording encoding method different from the transmission encoding method. May be. In the latter case, an encoding unit (not shown) for encoding the moving image acquired from the decoding unit PROD_B3 according to the recording encoding method may be interposed between the decoding unit PROD_B3 and the recording medium PROD_B5.
  • the transmission medium for transmitting the modulation signal may be wireless or wired.
  • the transmission mode for transmitting the modulated signal may be broadcasting (here, a transmission mode in which the transmission destination is not specified in advance) or communication (here, transmission in which the transmission destination is specified in advance). Refers to the embodiment). That is, the transmission of the modulation signal may be realized by any of wireless broadcasting, wired broadcasting, wireless communication, and wired communication.
  • a terrestrial digital broadcast broadcasting station (broadcasting equipment, etc.) / Receiving station (such as a television receiver) is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives a modulated signal by wireless broadcasting.
  • a broadcasting station (such as broadcasting equipment) / receiving station (such as a television receiver) of cable television broadcasting is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives a modulated signal by cable broadcasting.
  • a server workstation, etc.
  • Client television receiver, personal computer, smartphone, etc.
  • VOD Video On Demand
  • video sharing service using the Internet is a transmission device that transmits and receives modulated signals via communication.
  • PROD_A / receiving device PROD_B normally, either a wireless or wired transmission medium is used in a LAN, and a wired transmission medium is used in a WAN.
  • the personal computer includes a desktop PC, a laptop PC, and a tablet PC.
  • the smartphone also includes a multi-function mobile phone terminal.
  • the video sharing service client has a function of encoding a moving image captured by the camera and uploading it to the server. That is, the client of the video sharing service functions as both the transmission device PROD_A and the reception device PROD_B.
  • FIG. 42 (a) is a block diagram illustrating a configuration of a recording apparatus PROD_C in which the above-described image encoding device 11 is mounted.
  • the recording apparatus PROD_C includes an encoding unit PROD_C1 that obtains encoded data by encoding a moving image, and the encoded data obtained by the encoding unit PROD_C1 on the recording medium PROD_M.
  • the above-described image encoding device 11 is used as the encoding unit PROD_C1.
  • the recording medium PROD_M may be of a type built into the recording device PROD_C, such as (1) HDD (HardDisk Drive) or SSD (Solid State Drive), or (2) SD memory card. Or a type connected to the recording device PROD_C, such as a USB (Universal Serial Bus) flash memory, or (3) DVD (Digital Versatile Disc) or BD (Blu-ray Disc: registered trademark) ) And the like may be loaded into a drive device (not shown) built in the recording device PROD_C.
  • a type built into the recording device PROD_C such as (1) HDD (HardDisk Drive) or SSD (Solid State Drive), or (2) SD memory card.
  • a type connected to the recording device PROD_C such as a USB (Universal Serial Bus) flash memory, or (3) DVD (Digital Versatile Disc) or BD (Blu-ray Disc: registered trademark)
  • DVD Digital Versatile Disc
  • BD Blu-ray Disc: registered trademark
  • the recording device PROD_C is a camera PROD_C3 that captures moving images as a source of moving images to be input to the encoding unit PROD_C1, an input terminal PROD_C4 for inputting moving images from the outside, and a reception for receiving moving images
  • a unit PROD_C5 and an image processing unit PROD_C6 for generating or processing an image may be further provided.
  • FIG. 42A illustrates a configuration in which the recording apparatus PROD_C includes all of these, but some of them may be omitted.
  • the receiving unit PROD_C5 may receive a non-encoded moving image, or may receive encoded data encoded by a transmission encoding scheme different from the recording encoding scheme. You may do. In the latter case, a transmission decoding unit (not shown) that decodes encoded data encoded by the transmission encoding method may be interposed between the reception unit PROD_C5 and the encoding unit PROD_C1.
  • Examples of such a recording device PROD_C include a DVD recorder, a BD recorder, and an HDD (Hard Disk Drive) recorder (in this case, the input terminal PROD_C4 or the receiving unit PROD_C5 is a main source of moving images).
  • a camcorder in this case, the camera PROD_C3 is a main source of moving images
  • a personal computer in this case, the receiving unit PROD_C5 or the image processing unit C6 is a main source of moving images
  • a smartphone this In this case, the camera PROD_C3 or the receiving unit PROD_C5 is a main source of moving images).
  • FIG. 42 (b) is a block diagram showing a configuration of a playback device PROD_D equipped with the image decoding device 31 described above.
  • the playback device PROD_D reads a moving image by decoding a read unit PROD_D1 that reads encoded data written on the recording medium PROD_M and a read unit PROD_D1 that reads the encoded data. And a decoding unit PROD_D2 to obtain.
  • the above-described image decoding device 31 is used as the decoding unit PROD_D2.
  • the recording medium PROD_M may be of the type built into the playback device PROD_D, such as (1) HDD or SSD, or (2) such as an SD memory card or USB flash memory. It may be of the type connected to the playback device PROD_D, or (3) may be loaded into a drive device (not shown) built in the playback device PROD_D, such as a DVD or BD. Good.
  • the playback device PROD_D has a display unit PROD_D3 that displays a moving image as a supply destination of the moving image output by the decoding unit PROD_D2, an output terminal PROD_D4 that outputs the moving image to the outside, and a transmission unit that transmits the moving image.
  • PROD_D5 may be further provided.
  • FIG. 42B illustrates a configuration in which the playback apparatus PROD_D includes all of these, but a part of the configuration may be omitted.
  • the transmission unit PROD_D5 may transmit a non-encoded moving image, or transmits encoded data encoded by a transmission encoding scheme different from the recording encoding scheme. You may do. In the latter case, it is preferable to interpose an encoding unit (not shown) that encodes a moving image using a transmission encoding method between the decoding unit PROD_D2 and the transmission unit PROD_D5.
  • Examples of such a playback device PROD_D include a DVD player, a BD player, and an HDD player (in this case, an output terminal PROD_D4 to which a television receiver or the like is connected is a main moving image supply destination).
  • a television receiver in this case, the display PROD_D3 is a main supply destination of moving images
  • a digital signage also referred to as an electronic signboard or an electronic bulletin board
  • the display PROD_D3 or the transmission unit PROD_D5 is the main supply of moving images.
  • Display PROD_D3 or transmission unit PROD_D5 is video
  • a smartphone which is a main image supply destination
  • a smartphone in this case, the display PROD_D3 or the transmission unit PROD_D5 is a main moving image supply destination
  • the like are also examples of such a playback device PROD_D.
  • Each block of the image decoding device 31 and the image encoding device 11 described above may be realized in hardware by a logic circuit formed on an integrated circuit (IC chip), or may be a CPU (Central Processing Unit). You may implement
  • IC chip integrated circuit
  • CPU Central Processing Unit
  • each of the above devices stores a CPU that executes instructions of a program that realizes each function, a ROM (ReadOnly Memory) that stores the program, a RAM (RandomAccess Memory) that expands the program, the program, and various data.
  • a storage device such as a memory for storing is provided.
  • the object of the embodiment of the present invention is a record in which the program code (execution format program, intermediate code program, source program) of the control program for each of the above devices, which is software that realizes the above-described functions, is recorded in a computer-readable manner. This can also be achieved by supplying a medium to each of the above devices, and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).
  • Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, CD-ROMs (Compact Disc Read-Only Memory) / MO discs (Magneto-Optical discs).
  • tapes such as magnetic tapes and cassette tapes
  • magnetic disks such as floppy (registered trademark) disks / hard disks
  • CD-ROMs Compact Disc Read-Only Memory
  • MO discs Magnetic-Optical discs
  • IC cards including memory cards
  • Cards such as optical cards
  • Semiconductor memories such as flash ROM, or PLD (Programmable logic device)
  • Logic circuits such as FPGA and Field (Programmable Gate) Array can be used.
  • each of the above devices may be configured to be connectable to a communication network, and the program code may be supplied via the communication network.
  • the communication network is not particularly limited as long as it can transmit the program code.
  • the Internet Intranet, Extranet, LAN (Local Area Network), ISDN (Integrated Services Digital Network), VAN (Value-Added Network), CATV (Community Area Antenna / television / CableTelevision) communication network, Virtual Private Network (Virtual Private Network) ), Telephone line networks, mobile communication networks, satellite communication networks, and the like.
  • the transmission medium constituting the communication network may be any medium that can transmit the program code, and is not limited to a specific configuration or type.
  • IEEE Institute of Electrical and Electronic Engineers 1394, USB, power line carrier, cable TV line, telephone line, ADSL (Asymmetric Digital Subscriber Line) line, etc. wired such as IrDA (Infrared Data Association) and remote control, Wireless such as BlueTooth (registered trademark), IEEE802.11 wireless, HDR (High Data Rate), NFC (Near Field Communication), DLNA (Digital Living Network Alliance: registered trademark), mobile phone network, satellite line, digital terrestrial broadcasting network, etc. But it is available.
  • the embodiment of the present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.
  • Image coding device (moving image coding device, predicted image generation device) 31 Image decoding device (moving image decoding device, predicted image generation device) 112 Inter prediction parameter encoding unit (motion vector generation device) 303 Inter prediction parameter decoding unit (motion vector generation device) 3036 Merge prediction parameter derivation unit (merge processing unit) 3038 BTM processing unit 30373 Matching prediction unit (first motion vector search unit, second motion vector search unit)

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  • Compression Or Coding Systems Of Tv Signals (AREA)

Abstract

La présente invention vise à améliorer une efficacité de codage. Une unité de décodage de paramètre inter-prédiction (303) comprend une unité de traitement BTM (3038) qui exécute un traitement de mise en correspondance via une mise en correspondance de modèle bilatéral (BTM) en utilisant, comme modèle, un bloc prédit généré à partir d'un vecteur de mouvement déduit par une unité de déduction de paramètre de prédiction de fusion (3036), de sorte à modifier le vecteur de mouvement, et l'unité de traitement BTM (3038) exécute le traitement de mise en correspondance via l'exécution d'une mise en correspondance de modèle bilatéral une pluralité de fois.
PCT/JP2017/040838 2016-12-15 2017-11-14 Dispositif de génération de vecteur de mouvement, dispositif de génération d'image prédite, dispositif de décodage d'image animée, et dispositif de codage d'image animée Ceased WO2018110180A1 (fr)

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CN111837386A (zh) * 2018-09-21 2020-10-27 Kddi 株式会社 图像解码装置、图像编码装置、图像处理系统和程序
JP7026286B1 (ja) 2018-09-21 2022-02-25 Kddi株式会社 画像復号装置、画像符号化装置、画像処理システム及びプログラム
JP2020053723A (ja) * 2018-09-21 2020-04-02 Kddi株式会社 画像復号装置、画像符号化装置、画像処理システム及びプログラム
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US11882308B2 (en) 2018-09-21 2024-01-23 Kddi Corporation Image decoding device, image encoding device, image processing system, and program
WO2020059459A1 (fr) * 2018-09-21 2020-03-26 Kddi株式会社 Dispositif de décodage d'image, dispositif d'encodage d'image, système de traitement d'image et programme
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JP2022078071A (ja) * 2021-11-10 2022-05-24 Kddi株式会社 画像復号装置、画像符号化装置、画像処理システム及びプログラム
JP2024029090A (ja) * 2021-11-10 2024-03-05 Kddi株式会社 画像復号装置、画像符号化装置、画像処理システム及びプログラム
JP7685039B2 (ja) 2021-11-10 2025-05-28 Kddi株式会社 画像復号装置、画像符号化装置、画像処理システム及びプログラム
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WO2024074094A1 (fr) * 2022-10-05 2024-04-11 Mediatek Inc. Inter-prédiction dans un codage vidéo

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