RU2801154C1 - Device and method for motion vector encoding and device and method for motion vector decoding - Google Patents

Abstract

FIELD: image encoding and decoding.

SUBSTANCE: resolution of the motion vectors of the current block is determined. The first neighbouring block is selected from the plurality of neighbouring blocks adjacent to the current block using the resolution of the motion vectors of the current block. If the current block refers to a reference frame in list 0 and the first neighbouring block refers to a reference frame in list 0, a motion vector predictor is determined using the motion vector of the first neighbouring block. If the current block refers to a reference frame in list 0 and the first neighbouring block refers to a reference frame in list 1, the default motion vector is determined based on the motion vector of the second neighbouring block from the plurality of neighbouring blocks adjacent to the current block, and the motion vector predictor of the current block is determined by using the default motion vector. A bitstream is generated containing information indicating the resolution of the motion vectors of the current block and the differential motion vector determined using the motion vector of the current block and the predictor of the motion vector of the current block.

EFFECT: increased efficiency of image encoding.

9 cl, 32 dwg

Description

The technical field to which the invention belongs

The disclosure relates to the art of encoding and decoding images. More specifically, the disclosure relates to equipment and a method for encoding and decoding a current motion vector by using its adjacent motion vector.

State of the art

In image encoding and decoding, an image is divided into blocks, and each block is predictively encoded (prediction) and predictively decoded via inter-frame (inter-) prediction or intra-frame (intra-) prediction.

Inter-prediction is a technique for removing temporal redundancy between images in order to compress images. A typical example of inter-prediction is motion estimation coding. Motion estimation coding predicts blocks of the current frame by using at least one reference frame. The reference block that is most similar to the current block is searched within a predetermined search range by using a predetermined evaluation function. The current block is predicted based on the reference block, and a prediction block generated as a prediction result is subtracted from the current block to form a residual block. The residual block is then encoded. In order to perform prediction more accurately, interpolation is performed on a reference frame to generate pixels in a sub-pellet unit that is smaller than an integer unit, and inter-prediction is performed based on the pixels in the sub-pellet unit.

In a codec such as H.264 Advanced Video Coding (AVC) and High Efficiency Video Coding (HEVC), motion vectors of previously coded blocks adjacent to the current block or blocks included in previously coded pictures are used to to predict the motion vector of the current block. The differential motion vectors, which represent the differences between the motion vectors of the current block and the motion vectors of previously encoded blocks, are signaled to the decoder side via a preset method.

Detailed description of embodiments

Technical task

Equipment and method for motion vector encoding and equipment and method for motion vector decoding are provided, which improve the accuracy of motion vector prediction of the current block.

Equipment and method for motion vector encoding and equipment and method for motion vector decoding are provided, which reduce the size of a differential motion vector included in a bit stream.

The solution of the problem

A motion vector decoding method according to an embodiment includes selecting a first neighboring block from neighboring blocks adjacent to the current block according to information obtained from the bitstream; when the first neighbor block is identified as available by using information indicating the availability of the first neighbor block, and the motion vector of the first neighbor block in the prediction direction identical to the prediction direction of the current block does not exist, obtaining the prediction motion vector of the current block from the motion vector of the second neighbor block in advance a specific location, and the second neighboring block is adjacent to the current block; and deriving a motion vector of the current block by combining the predictive motion vector of the current block with the differential motion vector.

Disclosure Benefits

In the motion vector encoding equipment and method and the motion vector decoding equipment and method according to the embodiment, the motion vector prediction accuracy of the current block can be improved.

In the equipment and method for motion vector coding and in the equipment and method for motion vector decoding, according to an embodiment, the size of the differential motion vector included in the bitstream can be reduced.

It should be noted that the advantages that can be achieved by the motion vector encoding equipment and method and the motion vector decoding equipment and method according to the embodiment are not limited to the advantages described above, and other advantages that are not mentioned should become apparent to those skilled in the art. in the art from the following descriptions.

Brief description of the drawings

A brief description of each drawing is provided for a better understanding of the drawings provided in this document.

Fig. 1 is a block diagram of an image decoding equipment according to an embodiment.

Fig. 2 is a block diagram of an image encoding equipment according to an embodiment.

Fig. 3 illustrates a process for determining at least one coding unit by splitting the current coding unit, according to an embodiment.

Fig. 4 illustrates a process for determining at least one coding unit by splitting a non-square coding unit, according to an embodiment.

Fig. 5 illustrates a splitting process of a coding unit based on at least one of block shape information and mode information according to the split shape, according to an embodiment.

Fig. 6 illustrates a method for determining a preset coding unit from an odd number of coding units, according to an embodiment.

Fig. 7 illustrates a processing order of a plurality of coding units in determining a plurality of coding units by splitting a current coding unit, according to an embodiment.

Fig. 8 illustrates a process for determining that the current coding unit should be split into an odd number of coding units when the coding units are not pre-processable, according to an embodiment.

Fig. 9 illustrates a process for determining at least one coding unit by splitting the first coding unit, according to an embodiment.

Fig. 10 illustrates that the shape into which the non-square second coding unit, determined by splitting the first coding unit, is split is limited when the second coding unit satisfies a predetermined condition, according to an embodiment.

Fig. 11 illustrates a process of splitting a square coding unit when the mode information according to the split form does not indicate a split in units of four square coding units, according to an embodiment.

Fig. 12 illustrates that the processing order between the plurality of coding units may change depending on the coding unit partitioning process according to the embodiment.

Fig. 13 illustrates a process for determining the depth of a coding unit as the shape and size of a coding unit change when a coding unit is recursively split such that a plurality of coding units are determined, according to an embodiment.

Fig. 14 illustrates depths that are definable based on shapes and sizes of coding units and part indices (PIDs) for distinguishing coding units, according to an embodiment.

Fig. 15 illustrates that a plurality of coding units are determined based on a plurality of preset data units included in a frame, according to an embodiment.

Fig. 16 illustrates individual frame coding units when individual frames have different combinations of coding unit split shapes, according to an embodiment.

Fig. 17 illustrates various forms of coding units that can be determined based on mode information according to a partition form that is expressed in binary according to an embodiment.

Fig. 18 illustrates other forms of coding units that can be determined based on mode information according to a partition form that is expressed in binary according to an embodiment.

Fig. 19 is a block diagram of an image encoding and decoding system.

Fig. 20 is a block diagram of an image decoding equipment according to an embodiment.

Fig. 21A illustrates the locations of adjacent blocks when the left block relative to the current block is available.

Fig. 21B illustrates the locations of neighboring blocks when a left block and a right block relative to the current block are available.

Fig. 21C illustrates the locations of adjacent blocks when the right block relative to the current block is available.

Fig. 22 is a table showing a match-based relationship between indexes of motion vector permissions, motion vector permissions, and neighboring block locations.

Fig. 23A illustrates a case in which the reference frame index of the first adjacent block in the same prediction direction as the current block is not the same as a predetermined value.

Fig. 23B illustrates a case in which the reference frame index of the first adjacent block in the same prediction direction as the current block is the same as a predetermined value.

Fig. 23C illustrates a case in which, when the prediction direction of the current block is the dual direction, one of the reference frame index of the first neighbor block in the list 0 direction and the reference frame index of the first neighbor block in the list 1 direction is the same as the predetermined value, and the other is not identical to the predefined value.

Fig. 24 is a flowchart of a motion vector decoding method according to an embodiment.

Fig. 25 is a block diagram of an image encoding equipment according to an embodiment.

Fig. 26 is a flowchart of a motion vector encoding method according to an embodiment.

Fig. 27 is a view for explaining a process for obtaining a predictive motion vector according to the embodiment.

Fig. 28 is a view for explaining a process for obtaining a predictive motion vector according to the embodiment.

Optimal Mode for Carrying Out the Invention

A motion vector decoding method according to an embodiment includes selecting a first neighboring block from neighboring blocks adjacent to the current block according to information obtained from the bit stream; when the first neighbor block is identified as available by using information indicating the availability of the first neighbor block, and the motion vector of the first neighbor block in the prediction direction identical to the prediction direction of the current block does not exist, obtaining the prediction motion vector of the current block from the motion vector of the second neighbor block in advance a specific location, and the second neighboring block is adjacent to the current block; and deriving a motion vector of the current block by combining the predictive motion vector of the current block with the differential motion vector.

When the index of the reference frame of the second neighbor block in the same prediction direction as the current block is -1, the motion vector of the first neighbor block in the same prediction direction as the current block may not exist.

The accessibility of the first neighbor block may be determined according to at least one of whether or not the tile (cell) including the first neighbor block differs from the tile including the current block, whether or not the first neighbor block is located outside of the current frame, whether the first neighbor block is predicted by intra-prediction or not, and whether the first neighbor block is recovered or not.

Obtaining a motion vector of the current block may include, when a first neighboring block is identified as available by using information indicating the availability of the first neighboring block, and a motion vector of the first neighboring block in a prediction direction identical to the prediction direction of the current block exists, obtaining a predictive motion vector of the current block from the motion vector of the first neighboring block.

The information obtained from the bitstream may include information indicating the motion vector resolution of the current block from the set of motion vector resolutions, and the set of motion vector resolutions may correspond to neighboring blocks at different locations.

The location of the second neighboring block may vary according to information indicating the availability of the left and right neighboring blocks relative to the current block.

Obtaining the predictive motion vector of the current block may include when the second neighboring block is identified as available by using information indicating the availability of the second neighboring block, and the reference frame index of the second neighboring block in the prediction direction identical to the current block prediction direction is identical to the reference frame index of the current block, or a motion vector of the second neighboring block in the prediction direction identical to the prediction direction of the current block exists, obtaining the prediction motion vector of the current block from the motion vector of the second neighboring block.

Obtaining a predictive motion vector of the current block may include, when the second neighboring block is identified as unreachable by using information indicating the availability of the second neighboring block, or the motion vector of the second neighboring block in a prediction direction identical to the prediction direction of the current block does not exist, obtaining a prediction vector motion of the current block from the motion vector of the block decoded before the current block.

Obtaining the predictive motion vector of the current block may include, when the first neighboring block is identified as unreachable, obtaining the predictive motion vector of the current block from the motion vector of the second neighboring block.

The image decoding equipment according to the embodiment includes a motion vector prediction module configured to select a first neighbor block from among neighbor blocks adjacent to the current block according to information obtained from the bit stream, and when the first neighbor block is identified as available by using the information indicating the availability of the first neighboring block, and the motion vector of the first neighboring block in the prediction direction identical to the prediction direction of the current block does not exist, obtain the prediction motion vector of the current block from the motion vector of the second neighboring block at a predetermined location, the second neighboring block being adjacent to the current block; and a motion vector recovery module, configured to obtain a motion vector of the current block by combining the predictive motion vector of the current block with the differential motion vector.

A motion vector encoding method according to an embodiment includes, when a first neighboring block selected from among neighboring blocks adjacent to the current block is identified as available, and the motion vector of the first neighboring block in a prediction direction identical to the prediction direction of the current block is not exists, deriving a predictive motion vector of the current block from a motion vector of a second neighboring block at a predetermined location, the second neighboring block being adjacent to the current block; and generating a bitstream including a differential motion vector between the motion vector of the current block and the predictive motion vector of the current block, and information for indicating a first neighboring block.

Mode according to disclosure

Since the disclosure allows for various variations and many embodiments, specific embodiments are illustrated in the drawings and described in detail in the written description. However, it is not intended to limit the disclosure to particular modes of practice, and it should be appreciated that all modifications, equivalents, and replacements that do not depart from the spirit and scope of the disclosure are included in the disclosure.

In the description of embodiments of the disclosure, certain detailed explanations of the prior art are omitted when it is believed that they may unnecessarily obscure the essence of the disclosure. Although terms such as "first", "second", etc. may be used to describe various components, such components should not be limited to the above terms. The above terms are only used to distinguish one component from another.

When an element (e.g., the first element) "connects" or "connects" to another element (e.g., the second element), the first element may directly connect to or connect to the second element, or, unless otherwise described, the third element may exist between them.

With respect to a component presented as a "part (unit)" or "module" used herein, two or more components may be combined into one component, or one component may be separated into two or more components according to subdivided functions. In addition, each component described below may further perform some or all of the functions performed by the other component in addition to its primary functions, and some of the primary functions of each component may be performed entirely by the other component.

In addition, the term "image" or "frame" as used herein may refer to a still image of a video or a moving frame (video).

In addition, the term “sample” or “signal” used herein means, as the data assigned to the image sampling location, data to be processed. For example, the pixel values for a spatial region image and the transform coefficients for a transform region may be samples. A unit including such one or more samples may be defined as a block.

Hereinafter, this document describes an image encoding method and equipment and an image decoding method and equipment based on coding units and transformation units having a tree structure according to an embodiment with reference to FIG. 1-19.

Fig. 1 is a block diagram of an image decoding equipment 100 according to an embodiment.

The image decoding equipment 100 may include a bitstream acquisition unit 110 and a decoder 120. The bitstream acquisition unit 110 and decoder 120 may include at least one processor. The bitstream receiving module 110 and the decoder 120 may include a memory storing instructions to be executed by at least one processor.

The bitstream receiving module 110 may receive a bitstream. The bitstream may include information resulting from image encoding by image encoding equipment 200, which is described below. The bit stream may be transmitted from the image encoding equipment 200 . The image decoding equipment 100 may be connected to the image encoding equipment 200 in a wired or wireless manner, and the bitstream receiving unit 110 may receive the bitstream in a wired or wireless manner. The bit stream receiving unit 110 may receive a bit stream from a storage medium such as optical media, a hard disk, and so on. Decoder 120 may reconstruct the image based on the information obtained from the received bit stream. Decoder 120 may receive a syntax element for reconstructing an image from the bit stream. Decoder 120 may reconstruct the image based on the syntax element.

With a detailed description of the operation of the image decoding equipment 100, the bitstream obtaining unit 110 may receive a bitstream.

The image decoding equipment 100 may perform an operation of obtaining a bin string corresponding to a mode according to a coding unit partition form from a bit stream. The image decoding equipment 100 may perform an operation of determining a splitting rule of a coding unit. The image decoding equipment 100 may perform an operation of splitting a coding unit into a plurality of coding units based on at least one of a bin string corresponding to a mode according to the split shape and a split rule. The image decoding equipment 100 may determine a first range, which is a valid coding unit size range, according to a height-to-width ratio of the coding unit, to determine a splitting rule. The image decoding equipment 100 may determine a second range, which is a valid range of sizes of a coding unit, according to a mode according to a split shape of a coding unit, to determine a split rule.

Hereinafter, this document describes in detail the partitioning of a coding unit according to an embodiment of the disclosure.

First, one frame can be divided into one or more slices or one or more tiles. One slice or one tile may be a sequence of one or more largest coding units (coding tree units (CTU)). According to an implementation example, one slice includes one or more tiles, or one slice may include one or more largest coding units. A slice including a single tile or a plurality of tiles may be defined in a frame.

There is a largest coding unit (a coding tree block (CTB)) conceptually compared to a largest coding unit (CTU). The largest coding block (CTB) denotes an NxN block including NxN samples (where N is an integer). Each color component may be decomposed into one or more larger coding units.

When a frame has three sample arrays (sample arrays for Y, Cr, and Cb components), the largest coding unit (CTU) includes the largest luminance sample coding unit, the two corresponding largest chrominance sample coding units, and the syntax structures used to to encode the luma sample and the chrominance sample. When a frame is a monochrome frame, the largest coding unit includes the largest monochrome sample coding unit and the syntax structures used to encode the monochrome samples. When a frame is a frame encoded in color planes separated according to color components, the largest coding unit includes the syntax structures used to encode samples of the frame.

One largest coding block (CTB) may be split into MxN coding blocks including MxN samples (M and N are integers).

When a frame has arrays of samples for Y, Cr, and Cb components, a coding unit (CU) includes a luminance sample coding block, two corresponding chrominance sample coding blocks, and syntax structures used to encode the luminance sample and the chrominance samples. . When a frame is a monochrome frame, the coding unit includes a monochrome sample coding block and syntax structures used to encode monochrome samples. When a frame is a frame encoded in color planes separated according to color components, the coding unit includes the syntax structures used to encode samples of the frame.

As described above, the largest coding unit and the largest coding unit are conceptually different from each other, and the coding unit and the coding unit are conceptually different from each other. In other words, the (largest) coding unit means a data structure including a (largest) coding unit including a corresponding sample and a syntax structure corresponding to the (largest) coding unit. However, as those skilled in the art would understand that a (largest) coding unit or (largest) coding unit means a predetermined size block including a predetermined number of samples, a largest coding unit, and a largest coding unit, or a coding block and the coding unit is referred to in the following description of the invention without distinction, unless otherwise stated.

The picture may be split into largest coding units (CTU). The size of each largest coding unit may be determined based on information obtained from the bit stream. The shape of each largest coding unit may be an identically sized square shape. However, embodiments of the disclosure are not limited to this.

For example, information regarding the maximum luminance coding block size may be obtained from the bitstream. For example, the maximum luminance coding block size indicated by information regarding the maximum luminance coding block size may be one of 4x4, 8x8, 16x16, 32x32, 64x64, 128x128, and 256x256.

For example, information regarding the size difference of the luminance blocks and the maximum size of the luminance coding block that can be split into two may be obtained from the bitstream. The information regarding the size difference of luminance blocks may mean the difference in sizes between the largest luminance coding unit and the largest luminance coding block that can be split into two. Accordingly, when information regarding a maximum luminance coding block size that can be split into two and information regarding a luminance block size difference obtained from a bitstream are combined with each other, a size of the largest luminance coding unit can be determined. The size of the largest chroma coding unit may be determined by using the size of the largest luminance coding unit. For example, when the Y:Cb:Cr ratio is 4:2:0 according to the color format, the chrominance block size may be half of the luminance block size, and the size of the largest chroma coding unit may be half of the size of the largest luminance coding unit.

According to an embodiment, since information regarding a maximum size of a luminance coding block that is binary-separable is obtained from a bit stream, a maximum size of a luminance coding block that is binary-separable can be variably determined. In contrast, the maximum size of a luma coding block that is tripartite-separable may be fixed. For example, the maximum size of a luma coding block that is tri-separable in an I-frame may be 32×32, and the maximum size of a luminance coding block that is tri-separable in a P-frame or a B-frame may be 64×64.

The largest coding unit may be hierarchically partitioned into coding units based on the mode information according to the partition form obtained from the bit stream. At least one of information indicating whether or not quadratic splitting is performed, information indicating whether or not multi-partitioning is performed, splitting direction information, and splitting type information can be obtained as mode information according to the splitting form from the bit stream.

For example, information indicating whether or not quadratic splitting is performed may indicate whether the current coding unit (QUAD_SPLIT) is quadratically split or not.

When the current coding unit is not quadratically split, information indicating whether or not multi-splitting is performed may indicate whether the current coding unit is no longer split (NO_SPLIT) or binary/ternary split.

When the current coding unit is binary split or ternary split, the split direction information indicates that the current coding unit is split in one of the horizontal direction and the vertical direction.

When the current coding unit is split in the horizontal direction or in the vertical direction, the split type information indicates that the current coding unit is binary split or ternary split.

The split mode of the current coding unit may be determined according to split direction information and split type information. The split mode when the current coding unit is binary split in the horizontal direction may be determined as the binary horizontal split mode (SPLIT_BT_HOR), the split mode when the current coding unit is triple split in the horizontal direction may be determined as the ternary horizontal split mode (SPLIT_TT_HOR), a split mode when the current coding unit is binary split in the vertical direction may be determined as a binary vertical split mode (SPLIT_BT_VER), and a split mode when the current coding unit is triple split in the vertical direction may be determined as a ternary vertical split mode (SPLIT_TT_VER) .

The image decoding equipment 100 can obtain, from the bit stream, mode information according to a split form from one line of bins. The form of the bit stream received by the image decoding equipment 100 may include a fixed length binary code, a unary code, a truncated unary code, a predetermined binary code, and the like. A string of binary elements represents information in a binary number. The bin string may include at least one bit. The image decoding equipment 100 can obtain mode information according to the split shape corresponding to the bin string based on the split rule. The image decoding equipment 100 can determine whether or not to quadratically split a coding unit, whether or not to not split a coding unit, a split direction, and a split type, based on a single bin string.

The coding unit may be less than or identical to the largest coding unit. For example, since the largest coding unit is a coding unit having a maximum size, the largest coding unit is one of the coding units. When the mode information according to the split form with respect to the largest coding unit indicates that splitting is not performed, the coding unit specified in the largest coding unit has the same size as the size of the largest coding unit. When the mode information according to the split shape with respect to the largest coding unit indicates that splitting is performed, the largest coding unit may be split into coding units. In addition, when the mode information according to the split form with respect to a coding unit indicates that splitting is performed, the coding unit can be split into smaller coding units. However, image splitting is not limited to this, and the largest coding unit and the coding unit need not be different. In the following, partitioning of a coding unit will be described in detail with reference to FIG. 3-16.

In addition, one or more prediction blocks for prediction may be determined from a coding unit. The prediction block may be the same as or smaller than the coding unit. In addition, one or more transform blocks for transform may be determined from a coding unit. The transform block may be equal to or less than the coding unit.

The shapes and sizes of the transformation block and the prediction block may not be related to each other.

In another embodiment, prediction may be performed by using the coding unit as a predictor. In addition, the transformation can be performed by using the coding unit as the transformation block.

In the following, partitioning of a coding unit will be described in detail with reference to FIG. 3-16. The current block and the adjacent block according to the present disclosure may indicate one of the largest coding unit, coding unit, prediction block, and transform block. In addition, the current block of the current coding unit is a block that is currently being decoded or encoded, or a block that is currently being split. The adjacent block may be a block restored before the current block. An adjacent block may be spatially or temporally adjacent to the current block. The adjacent block can be located in one of the locations bottom left, left, top left, top, top right, right, bottom right relative to the current block.

Fig. 3 illustrates a process performed by the image decoding equipment 100 to determine at least one coding unit by splitting the current coding unit, according to an embodiment.

The block shape may include 4Nx4N, 4Nx2N, 2Nx4N, 4NxN, Nx4N, 32NxN, Nx32N, 16NxN, Nx16N, 8NxN, or Nx8N. Here, N can be a positive integer. The block shape information is information indicating at least one of a shape, a direction, a width-to-height ratio, or a size of a coding unit.

The shape of the coding unit may include square and non-square. When the width and height lengths of the coding unit are identical (ie, when the shape of the coding unit block is 4Nx4N), the image decoding equipment 100 may determine the shape information of the coding unit blocks as square. The image decoding equipment 100 may determine the shape of the coding unit to be non-square.

When the width and height of the coding unit are different from each other (i.e., when the shape of the coding unit block is 4Nx2N, 2Nx4N, 4NxN, Nx4N, 32NxN, Nx32N, 16NxN, Nx16N, 8NxN, or Nx8N), the image decoding equipment 100 can determine information the shape of the coding unit blocks as a non-square shape. When the shape of the coding unit is non-square, the image decoding equipment 100 can determine the width-to-height ratio from the shape information of the coding unit blocks as being at least one of 1:2, 2:1, 1:4, 4:1, 1: 8, 8:1, 1:16, 16:1, 1:32 and 32:1. In addition, the image decoding equipment 100 can determine whether the coding unit is stretched in the horizontal direction or in the vertical direction based on the width length and the height length of the coding unit. In addition, the image decoding equipment 100 can determine the size of the coding unit based on at least one of the length of the width, the length of the height, or the area of the coding unit.

According to an embodiment, the image decoding equipment 100 can determine the shape of the coding unit by using the block shape information, and can determine the partitioning method of the coding unit by using the mode information according to the split shape. Thus, the splitting method of a coding unit indicated by the mode information according to the split shape can be determined based on the block shape indicated by the block shape information used by the image decoding equipment 100 .

The image decoding equipment 100 can obtain mode information according to the split shape from the bit stream. However, the embodiment is not limited to this, and the image decoding equipment 100 and the image encoding equipment 200 can determine the pre-negotiated mode information according to the partition shape based on the block shape information. The image decoding equipment 100 may determine the pre-negotiated mode information according to the partition shape with respect to the largest coding unit or the minimum coding unit. For example, the image decoding equipment 100 may determine the mode information according to the split shape with respect to the largest coding unit as the quadratic split. In addition, the image decoding equipment 100 may determine the mode information according to the split form with respect to the smallest coding unit as "do not split". In detail, the image decoding equipment 100 may determine the size of the largest coding unit to be 256×256. The image decoding equipment 100 may determine the pre-negotiated mode information according to the shape of the partition as a quadratic partition. Square splitting is a mode according to the splitting shape in which the width and height of a coding unit are divided in half. The image decoding equipment 100 can obtain a 128×128 coding unit from a 256×256 largest coding unit based on the mode information according to the split shape. In addition, the image decoding equipment 100 may determine the size of the smallest coding unit to be 4×4. The image decoding equipment 100 can obtain mode information according to a split shape indicating "do not split" with respect to the smallest coding unit.

According to an embodiment, the image decoding equipment 100 may use block shape information indicating that the current coding unit is square. For example, the image decoding equipment 100 may determine whether or not to split a square coding unit, whether or not to vertically split a square coding unit, whether or not to horizontally split a square coding unit, or whether or not to split a square unit. coding into four coding units, based on the mode information according to the split shape. Referring to FIG. 3, when the block shape information of the current coding unit 300 indicates a square shape, the decoder 120 may not split the coding unit 310a having the same size as the current coding unit 300 based on the mode information according to the split shape indicating the need not to split, or may determine coding units 310b, 310c, 310d, 310e, or 310f partitioned based on mode information according to a partitioning form indicating a preset partitioning method.

Referring to FIG. 3, according to the embodiment, the image decoding equipment 100 can determine two coding units 310b obtained by splitting the current coding unit 300 in the vertical direction based on mode information according to the split shape indicating whether to perform splitting in the vertical direction. The image decoding equipment 100 can determine two coding units 310c obtained by splitting the current coding unit 300 in the horizontal direction based on the mode information according to the split shape indicating the need to split in the horizontal direction. The image decoding equipment 100 can determine the four coding units 310d obtained by splitting the current coding unit 300 in the vertical and horizontal directions based on the split shape information indicating the need to split in the vertical and horizontal directions. According to an embodiment, the image decoding equipment 100 can determine the three coding units 310e obtained by splitting the current coding unit 300 in the vertical direction based on mode information according to the split shape indicating the need to perform ternary split in the vertical direction. The image decoding equipment 100 can determine three coding units 310f obtained by splitting the current coding unit 300 in the horizontal direction based on mode information according to the split shape indicating whether to perform ternary splitting in the horizontal direction. However, the splitting methods of the square coding unit are not limited to the above-described methods, and the mode information according to the splitting shape may indicate various methods. The following describes in detail the preset splitting methods for splitting a square coding unit with respect to various embodiments.

Fig. 4 illustrates a process performed by the image decoding equipment 100 to determine at least one coding unit by splitting a non-square coding unit, according to an embodiment.

According to an embodiment, the image decoding equipment 100 may use block shape information indicating that the current coding unit is non-square. The image decoding equipment 100 can determine whether or not to split the non-square current coding unit, or whether or not to split the non-square current coding unit by using a preset splitting method, based on the mode information according to the splitting shape. Referring to FIG. 4, when the shape information of the blocks of the current coding unit 400 or 450 indicates a non-square shape, the image decoding equipment 100 may determine the coding unit 410 or 460 having the same size as the current coding unit 400 or 450, based on the mode information according to the split shape indicating the need not perform splitting, or may determine coding units 420a and 420b, 430a-430c, 470a and 470b, or 480a-480c split based on mode information according to a splitting form indicating a preset splitting method. The following describes in detail the preset splitting methods for splitting a non-square coding unit with respect to various embodiments.

According to an embodiment, the image decoding equipment 100 may determine the splitting method of a coding unit by using the mode information according to the split shape, and in this case, the mode information according to the split shape can indicate the number of one or more coding units generated by splitting the coding unit. Referring to FIG. 4, when the mode information according to the split form indicates the need to split the current coding unit 400 or 450 into two coding units, the image decoding equipment 100 may determine the two coding units 420a and 420b or 470a and 470b included in the current coding unit 400 or 450 by splitting the current coding units 400 or 450 based on the mode information according to the split shape.

According to an embodiment, when the image decoding equipment 100 splits the non-square current coding unit 400 or 450 based on the mode information according to the split shape, the image decoding equipment 100 can consider the location of the long side of the non-square current coding unit 400 or 450 in order to split the current coding unit. For example, the image decoding equipment 100 may determine a plurality of coding units by splitting the current coding unit 400 or 450 in the split direction of the long side of the current coding unit 400 or 450, considering the shape of the current coding unit 400 or 450.

According to an embodiment, when the mode information according to the split shape indicates a need to split (triple split) a coding unit into an odd number of blocks, the image decoding equipment 100 may determine an odd number of coding units included in the current coding unit 400 or 450. For example, when the mode information according to the split form indicates the need to split the current coding unit 400 or 450 into three coding units, the image decoding equipment 100 may split the current coding unit 400 or 450 into three coding units 430a, 430b, and 430c or 480a, 480b, and 480c.

According to an embodiment, the width to height ratio of the current coding unit 400 or 450 may be 4:1 or 1:4. When the width-to-height ratio is 4:1, the block shape information may indicate a horizontal direction because the length of the width is longer than the length of the height. When the width-to-height ratio is 1:4, the block shape information may indicate a vertical direction because the width length is shorter than the height length. The image decoding equipment 100 may determine whether to split the current coding unit into an odd number of blocks based on the mode information according to the split shape. In addition, the image decoding equipment 100 can determine the splitting direction of the current coding unit 400 or 450 based on the block shape information of the current coding unit 400 or 450. For example, when the current coding unit 400 is stretched in the vertical direction, the image decoding equipment 100 may determine the coding units 430a, 430b, and 430c by splitting the current coding unit 400 in the horizontal direction. In addition, when the current coding unit 450 is in the horizontal direction, the image decoding equipment 100 can determine the coding units 480a, 480b, and 480c by splitting the current coding unit 450 in the vertical direction.

According to an embodiment, the image decoding equipment 100 may determine an odd number of coding units included in the current coding unit 400 or 450, and not all of the determined coding units may be of the same size. For example, a preset coding unit 430b or 480b of a certain odd number of coding units 430a, 430b and 430c or 480a, 480b and 480c may have a size different from that of other coding units 430a and 430c or 480a and 480c. Thus, the coding units that may be determined by splitting the current coding unit 400 or 450 may have multiple sizes, and, in some cases, an odd number of coding units 430a, 430b, and 430c or 480a, 480b, and 480c may all have different sizes. .

According to an embodiment, when the mode information according to the split shape indicates the need to split a coding unit into an odd number of blocks, the image decoding equipment 100 may determine an odd number of coding units included in the current coding unit 400 or 450, and furthermore, may impose a preset limit, by at least one coding unit from an odd number of coding units generated by splitting the current coding unit 400 or 450. Referring to FIG. 4, the image decoding equipment 100 may specify a decoding process with respect to the coding unit 430b or 480b located in the center of the three coding units 430a, 430b and 430c or 480a, 480b and 480c generated as the current 400 or 450 is split in this way. that it is different from other coding units 430a and 430c or 480a and 480c. For example, the image decoding equipment 100 may restrict the coding unit 430b or 480b at the central location such that it is no longer split or only splits a predetermined number of times, unlike other coding units 430a and 430c or 480a and 480c.

Fig. 5 illustrates a process performed by the image decoding equipment 100 for splitting a coding unit based on at least one of block shape information and mode information according to the split shape, according to an embodiment.

According to an embodiment, the image decoding equipment 100 can determine whether or not to split the square first coding unit 500 into coding units based on at least one of block shape information and mode information according to the split shape. According to an embodiment, when the mode information according to the split shape indicates the need to split the first coding unit 500 in the horizontal direction, the image decoding equipment 100 can determine the second coding unit 510 by splitting the first coding unit 500 in the horizontal direction. The first coding unit, the second coding unit, and the third coding unit used according to the embodiment are terms used to understand the relationship before and after splitting the coding unit. For example, the second coding unit may be determined by splitting the first coding unit, and the third coding unit may be determined by splitting the second coding unit. It should be understood that the relationship of the first coding unit, the second coding unit, and the third coding unit is as described above.

According to an embodiment, the image decoding equipment 100 may determine whether or not to split the determined second coding unit 510 into coding units based on the mode information according to the split shape. Referring to FIG. 5, the image decoding equipment 100 may split the non-square second coding unit 510, which is determined by splitting the first coding unit 500, into one or more third coding units 520a, 520b, 520c, and 520d based on at least one of the mode information according to the form splitting and mode information according to the split shape, or may not split the non-square second coding unit 510 . The image decoding equipment 100 may obtain mode information according to the split shape, and may obtain a plurality of second coding units of different shape (for example, 510) by splitting the first coding unit 500, based on the obtained mode information according to the split shape, and the second coding unit 510 can be split by using a splitting method of the first coding unit 500 based on the mode information according to the splitting form. According to an embodiment, when the first coding unit 500 is split into second coding units 510 based on the mode information according to the split form of the first coding unit 500, the second coding unit 510 may also be split into third coding units (eg, 520a or 520b, 520c, and 520d) into based on the mode information according to the partition shape of the second coding unit 510 . Thus, a coding unit can be recursively partitioned based on the mode information according to the partitioning shape of each coding unit. Therefore, a square coding unit may be determined by splitting a non-square coding unit, and a non-square coding unit may be determined by recursively splitting a square coding unit.

Referring to FIG. 5, a preset coding unit (eg, a coding unit located at a central location or a square coding unit) among an odd number of third coding units 520b, 520c, and 520d determined by splitting the non-square second coding unit 510 can be split recursively. According to an embodiment, the non-square third coding unit 520b of an odd number of third coding units 520b, 520c, and 520d may be split horizontally into a plurality of fourth coding units. The non-square fourth coding unit 530b or 530d of the plurality of fourth coding units 530a, 530b, 530c, and 530d may be re-partitioned into the plurality of coding units. For example, a non-square fourth coding unit 530b or 530d may be re-split into an odd number of coding units. The following describes a method that can be used to recursively split a coding unit with respect to various embodiments.

According to an embodiment, the image decoding equipment 100 may partition each of the third coding units 520a or 520b, 520c, and 520d into coding units based on the mode information according to the split shape. In addition, the image decoding equipment 100 can determine whether to not split the second coding unit 510 based on the mode information according to the split shape. According to an embodiment, the image decoding equipment 100 may partition the non-square second coding unit 510 into an odd number of third coding units 520b, 520c, and 520d. The image decoding equipment 100 may set a preset limit on a preset third coding unit from an odd number of third coding units 520b, 520c, and 520d. For example, the image decoding equipment 100 may limit the third coding unit 520c at the central location of an odd number of third coding units 520b, 520c, and 520d such that it is no longer split or split a predetermined number of times.

Referring to FIG. 5, the image decoding equipment 100 may limit the third coding unit 520c that is at the center location of an odd number of third coding units 520b, 520c, and 520d included in the non-square second coding unit 510 so that it is no longer split, split by using a predetermined a set splitting method (eg, only split into four coding units, or split by using the splitting method of the second coding unit 510) or split only a predetermined number of times (eg, split only n times (where n>0)). However, restrictions on the third coding unit 520c at the center location are not limited to the examples described above and may include various restrictions for decoding the third coding unit 520c at the center location differently compared to other third coding units 520b and 520d.

According to an embodiment, the image decoding equipment 100 can acquire mode information according to a split form that is used to split the current coding unit from a preset location in the current coding unit.

Fig. 6 illustrates a method implemented by the image decoding equipment 100 for determining a preset coding unit from an odd number of coding units, according to an embodiment.

Referring to FIG. 6, mode information according to the split form of the current coding unit 600 or 650 may be obtained from a preset location sample (eg, from a central location sample 640 or 690) from a plurality of samples included in the current coding unit 600 or 650. However, the preset location in the current coding unit 600 from which at least one piece of mode information according to the split shape can be derived is not limited to the center location in FIG. 6 and may include various locations included in the current coding unit 600 (eg, top, bottom, left, right, top left, bottom left, top right, bottom right locations, etc.). The image decoding equipment 100 can acquire mode information according to the split shape from a preset location, and can determine whether or not to split the current coding unit into coding units of various shapes and sizes.

According to an embodiment, when the current coding unit is divided into a predetermined number of coding units, the image decoding equipment 100 may select one of the coding units. Various methods may be used to select one of a plurality of coding units, as described below with respect to various embodiments.

According to an embodiment, the image decoding equipment 100 may partition the current coding unit into a plurality of coding units, and may determine the coding unit at a preset location.

According to an embodiment, the image decoding equipment 100 may use information indicating locations of an odd number of coding units to determine a coding unit at a central location from an odd number of coding units. Referring to FIG. 6, the image decoding equipment 100 may determine an odd number of coding units 620a, 620b, and 620c or an odd number of coding units 660a, 660b, and 660c by splitting the current coding unit 600 or the current coding unit 650. The image decoding equipment 100 may determine the average coding unit 620b or the average coding unit 660b by using information regarding the locations of an odd number of coding units 620a, 620b, and 620c or an odd number of coding units 660a, 660b, and 660c. For example, the image decoding equipment 100 may determine the central location coding unit 620b by determining the locations of the coding units 620a, 620b, and 620c based on information indicative of the locations of preset samples included in the coding units 620a, 620b, and 620c. In detail, the image decoding equipment 100 can determine the coding unit 620b at the center location by determining the locations of the coding units 620a, 620b, and 620c based on information indicating the locations of the top left samples 630a, 630b, and 630c of the coding units 620a, 620b, and 620c.

According to an embodiment, information indicating the locations of the top left samples 630a, 630b, and 630c that are included in coding units 620a, 620b, and 620c, respectively, may include information regarding the locations or coordinates of coding units 620a, 620b, and 620c in a frame. According to an embodiment, information indicative of the locations of the top left samples 630a, 630b, and 630c that are included in coding units 620a, 620b, and 620c, respectively, may include information indicative of the widths or heights of coding units 620a, 620b, and 620c included in the current coding unit 600, and the width or height may correspond to information indicating differences between the coordinates of the coding units 620a, 620b, and 620c in the frame. Thus, the image decoding equipment 100 can determine the coding unit 620b at the central location by directly using information regarding the locations or coordinates of the coding units 620a, 620b, and 620c in the frame, or by using information regarding the widths or heights of the coding units that correspond to the difference values between coordinates.

According to an embodiment, information indicating the location of the upper left sample 630a of the upper coding unit 620a may include coordinates (xa, ya), information indicating the location of the upper left sample 630b of the center coding unit 620b may include coordinates (xb, yb ), and information indicating the location of the upper left sample 630c of the lower coding unit 620c may include coordinates (xc, yc). The image decoding equipment 100 may determine the middle coding unit 620b by using the coordinates of the top left samples 630a, 630b, and 630c, which are included in the coding units 620a, 620b, and 620c, respectively. For example, when the coordinates of the top left samples 630a, 630b, and 630c are sorted in ascending or descending order, the coding unit 620b including the coordinates (xb, yb) of the sample 630b at the center location may be determined as the coding unit at the center location from among coding units 620a, 620b, and 620c determined by splitting the current coding unit 600. However, the coordinates indicating the locations of the top left samples 630a, 630b, and 630c may include coordinates indicating absolute locations in the frame, or may use coordinates (dxb, dyb) indicating the relative location of the top left sample 630b of the middle coding unit 620b. , and coordinates (dxc, dyc) indicating the relative location of the upper left sample 630c of the lower coding unit 620c with reference to the location of the upper left sample 630a of the upper coding unit 620a. The method for determining the coding unit at a preset location by using the sample coordinates included in the coding unit as information indicating the sample location is not limited to the above-described method, and may include various arithmetic methods capable of using the sample coordinates.

According to an embodiment, the image decoding equipment 100 may partition the current coding unit 600 into a plurality of coding units 620a, 620b, and 620c, and may select one of the coding units 620a, 620b, and 620c based on a predetermined criterion. For example, the image decoding equipment 100 may select a coding unit 620b that has a size different from the others from among the coding units 620a, 620b, and 620c.

According to an embodiment, the image decoding equipment 100 may determine the width or height of each of the coding units 620a, 620b, and 620c by using coordinates (xa, ya), which are information indicating the location of the upper left sample 630a of the upper coding unit 620a, coordinates (xb , yb), which are information indicating the location of the upper left sample 630b of the middle coding unit 620b, and coordinates (xc, yc), which are information indicating the location of the upper left sample 630c of the lower coding unit 620c. The image decoding equipment 100 may determine the respective sizes of the coding units 620a, 620b, and 620c by using the coordinates (xa, ya), (xb, yb), and (xc, yc) indicating the locations of the coding units 620a, 620b, and 620c. According to an embodiment, the image decoding equipment 100 may determine the width of the upper coding unit 620a as representing the width of the current coding unit 600. The image decoding equipment 100 may determine the height of the upper encoding unit 620a as the yb-ya component. According to an embodiment, the image decoding equipment 100 may determine the width of the middle coding unit 620b as being the width of the current coding unit 600. The image decoding equipment 100 may determine the height of the middle coding unit 620b as a component of yc-yb. According to an embodiment, the image decoding equipment 100 may determine the width or height of the lower coding unit 620c by using the width or height of the current coding unit 600 or the widths or heights of the upper and middle coding units 620a and 620b. The image decoding equipment 100 may determine a coding unit that has a size different from others based on the determined widths and heights of the coding units 620a, 620b, and 620c. Referring to FIG. 6, the image decoding equipment 100 may determine the middle coding unit 620b, which has a size different from the size of the upper and lower coding units 620a and 620c, as the preset location coding unit. However, the above-described method carried out by the image decoding equipment 100 for determining a coding unit having a size different from that of other coding units simply corresponds to an example of determining a coding unit at a preset location by using coding unit sizes that are determined based on coordinates samples, and thus various methods of determining the coding unit at the preset location by comparing the sizes of the coding units that are determined based on the coordinates of the preset samples can be used.

The image decoding equipment 100 may determine the width or height of each of the encoding units 660a, 660b, and 660c by using coordinates (xd, yd), which are information indicating the location of the upper left sample 670a of the left encoding unit 660a, coordinates (xe, ye), which are information indicating the location of the upper left sample 670b of the middle coding unit 660b, and coordinates (xf, yf) which are information indicating the location of the upper left sample 670c of the right coding unit 660c. The image decoding equipment 100 can determine the respective sizes of the coding units 660a, 660b, and 660c by using the coordinates (xd, yd), (xe, ye), and (xf, yf) indicating the locations of the coding units 660a, 660b, and 660c.

According to an embodiment, the image decoding equipment 100 may determine the width of the left encoding unit 660a as a component of xe-xd. The image decoding equipment 100 may determine the height of the left coding unit 660a as the height of the current coding unit 650 . According to an embodiment, the image decoding equipment 100 may determine the width of the middle coding unit 660b as a component of xf-xe. The image decoding equipment 100 may determine the height of the middle coding unit 660b as the height of the current coding unit 650 . According to an embodiment, the image decoding equipment 100 may determine the width or height of the right coding unit 660c by using the width or height of the current coding unit 650 or the widths or heights of the left and middle coding units 660a and 660b. The image decoding equipment 100 may determine a coding unit that has a size different from others based on the determined widths and heights of the coding units 660a, 660b, and 660c. Referring to FIG. 6, the image decoding equipment 100 may determine the middle coding unit 660b, which has a size different from the sizes of the left and right coding units 660a and 660c, as the preset location coding unit. However, the above-described method carried out by the image decoding equipment 100 for determining a coding unit having a size different from that of other coding units simply corresponds to an example of determining a coding unit at a preset location by using coding unit sizes that are determined based on coordinates samples, and thus various methods of determining the coding unit at the preset location by comparing the sizes of the coding units that are determined based on the coordinates of the preset samples can be used.

However, the sample locations taken into account in order to determine the locations of the coding units are not limited to the upper left locations described above, and information on arbitrary sample locations included in the coding units can be used.

According to an embodiment, the image decoding equipment 100 may select a coding unit at a preset location from an odd number of coding units determined by splitting the current coding unit based on the shape of the current coding unit. For example, when the current coding unit has a non-square shape whose width exceeds the height, the image decoding equipment 100 can determine the coding unit at a preset location in the horizontal direction. Thus, the image decoding equipment 100 may determine one of the coding units at various locations in the horizontal direction, and may impose a restriction on the coding unit. When the current coding unit has a non-square shape whose height exceeds the width, the image decoding equipment 100 can determine the coding unit at a preset location in the vertical direction. Thus, the image decoding equipment 100 may determine one of the coding units at various locations in the horizontal direction, and may impose a restriction on the coding unit.

According to an embodiment, the image decoding equipment 100 can use information indicating respective locations of an even number of coding units to determine a coding unit at a preset location from an even number of coding units. The image decoding equipment 100 may determine an even number of coding units by splitting (binary split) a current coding unit, and may determine a coding unit at a preset location by using information on the locations of an even number of coding units. The operation in this regard may correspond to the operation of determining a coding unit at a preset location (eg, a central location) from an odd number of coding units, which is described in detail above with respect to FIG. 6, and as such, detailed descriptions of what is meant are not provided here.

According to an embodiment, when a non-square current coding unit is split into a plurality of coding units, preset information regarding a coding unit at a preset location may be used in a split operation to determine a coding unit at a preset location from among the plurality of coding units. For example, the image decoding equipment 100 may use at least one of the block shape information and the mode information according to the split shape that is stored in the sample included in the middle coding unit in the split operation to determine the coding unit at the central location of a plurality of coding units determined by splitting the current coding unit.

Referring to FIG. 6, the image decoding equipment 100 may partition the current coding unit 600 into a plurality of coding units 620a, 620b, and 620c based on the mode information according to the split shape, and may determine the coding unit 620b at a central location from the plurality of coding units 620a, 620b, and 620c. In addition, the image decoding equipment 100 can determine the coding unit 620b at the central location, considering the location from which the mode information is obtained according to the partition shape. Thus, the mode information according to the split shape of the current coding unit 600 can be obtained from the sample 640 at the center location of the current coding unit 600, and when the current coding unit 600 is split into a plurality of coding units 620a, 620b, and 620c based on the mode information according to the split shape, the unit An encoding 620b including sample 640 may be determined as the encoding unit at the central location. However, the information used to determine the coding unit at the central location is not limited to the mode information according to the split shape, and various types of information may be used to determine the coding unit at the central location.

According to an embodiment, preset information for identifying a coding unit at a preset location may be obtained from a preset sample included in a coding unit to be determined. Referring to FIG. 6, the image decoding equipment 100 may use the mode information according to the partition shape that is obtained from the sample at the preset location in the current coding unit 600 (for example, from the sample at the center location of the current coding unit 600), so as to determine the coding unit in the preset location from the plurality of coding units 620a, 620b, and 620c determined by splitting the current coding unit 600 (eg, coding units at the central location from the plurality of split coding units). Thus, the image decoding equipment 100 can determine a sample at a preset location considering the block shape of the current coding unit 600, can determine a coding unit 620b including a sample from which preset information can be obtained (for example, mode information according to the split shape) , from a plurality of coding units 620a, 620b, and 620c determined by splitting the current coding unit 600, and may impose a predetermined restriction on the coding unit 620b. Referring to FIG. 6, according to an embodiment, the image decoding equipment 100 may determine the sample 640 at the center location of the current coding unit 600 as a sample from which preset information can be obtained, and may impose a preset limit on the coding unit 620b including the sample 640, in the decoding operation. However, the location of the sample from which the preset information may be obtained is not limited to the above-described location, and may include arbitrary locations of the samples included in the coding unit 620b to be determined, for limitation.

According to an embodiment, the location of a sample from which preset information may be obtained may be determined based on the shape of the current coding unit 600 . According to an embodiment, the block shape information may indicate whether the current coding unit is square or non-square, and a sample location from which preset information may be obtained may be determined based on the shape. For example, the image decoding equipment 100 may determine a sample located at the boundary to split at least one of the width and height of the current coding unit by half as a sample from which preset information can be obtained by using at least one from information regarding the width of the current coding unit and information regarding the height of the current coding unit. As another example, when the block shape information of the current coding unit indicates a non-square shape, the image decoding equipment 100 may determine one of the samples adjacent to the boundary for splitting the long side of the current coding unit in half as a sample from which preset information can be obtained.

According to an embodiment, when the current coding unit is split into a plurality of coding units, the image decoding equipment 100 can use the mode information according to the split shape to determine the coding unit at a preset location from the plurality of coding units. According to an embodiment, the image decoding equipment 100 can obtain mode information according to the split shape from a sample at a preset location in a coding unit, and can split a plurality of coding units that are generated by splitting the current coding unit by using mode information according to the split shape that is obtained from fetching a preset location in each of the plurality of coding units. Thus, a coding unit can be recursively partitioned based on mode information according to a split shape that is obtained from a sample at a preset location in each coding unit. The operation of recursively splitting a coding unit is described above with respect to FIG. 5, and as such, detailed descriptions of what is meant are not provided here.

According to an embodiment, the image decoding equipment 100 may determine one or more coding units by splitting the current coding unit, and may determine the decoding order of the one or more coding units based on a preset block (eg, the current coding unit).

Fig. 7 illustrates a processing order of a plurality of coding units when the image decoding equipment 100 determines a plurality of coding units by splitting a current coding unit, according to an embodiment.

According to an embodiment, the image decoding equipment 100 may determine the second coding units 710a and 710b by splitting the first coding unit 700 in the vertical direction, may determine the second coding units 730a and 730b by splitting the first coding unit 700 in the horizontal direction, or may determine the second units 750a, 750b, 750c, and 750d encoding by splitting the first coding unit 700 in vertical and horizontal directions based on the mode information according to the split shape.

Referring to FIG. 7, the image decoding equipment 100 may determine whether to process the second coding units 710a and 710b, which are determined by splitting the first coding unit 700 in the vertical direction, in order 710c in the horizontal direction. The image decoding equipment 100 may determine whether to process the second coding units 730a and 730b, which are determined by splitting the first coding unit 700 in the horizontal direction, in order 730c in the vertical direction. The image decoding equipment 100 may determine second coding units 750a, 750b, 750c, and 750d, which are determined by splitting the first coding unit 700 in vertical and horizontal directions, according to a predetermined order (e.g., raster scan order 750e or Z-scan order), in which processes the coding units in a line and then processes the coding units in the next line.

According to an embodiment, the image decoding equipment 100 can split coding units recursively. Referring to FIG. 7, the image decoding equipment 100 may determine a plurality of coding units 710a and 710b, 730a and 730b or 750a, 750b, 750c and 750d by splitting the first coding unit 700, and may split each of the determined plurality of units 710a, 710b, 730a, 730b, 750a recursively. , 750b, 750c and 750d encoding. The partitioning method of the plurality of coding units 710a and 710b, 730a and 730b or 750a, 750b, 750c and 750d may correspond to the partitioning method of the first coding unit 700. Accordingly, each of the plurality of coding units 710a and 710b, 730a and 730b or 750a, 750b, 750c and 750d may be independently partitioned into a plurality of coding units. Referring to FIG. 7, the image decoding equipment 100 may determine the second coding units 710a and 710b by splitting the first coding unit 700 in the vertical direction, and may determine whether or not to split each of the second coding units 710a and 710b independently.

According to an embodiment, the image decoding equipment 100 may determine the third coding units 720a and 720b by splitting the left second coding unit 710a in the horizontal direction, and may not split the right second coding unit 710b.

According to an embodiment, the processing order of coding units may be determined based on a coding unit split operation. In other words, the processing order of split coding units may be determined based on the processing order of coding units just before splitting. The image decoding equipment 100 may determine the processing order of the third coding units 720a and 720b determined by splitting the left second coding unit 710a independently of the right second coding unit 710b. Since the third coding units 720a and 720b are determined by splitting the left second coding unit 710a in the horizontal direction, the third coding units 720a and 720b can be processed in order 720c in the vertical direction. Since the left and right second coding units 710a and 710b are processed in the order 710c in the horizontal direction, the right second coding unit 710b can be processed after the third coding units 720a and 720b included in the left second coding unit 710a are processed in the order 720c in the vertical direction. direction. The operation of determining the processing order of coding units based on the coding unit before splitting is not limited to the above-described example, and various methods can be used to independently process coding units that are split and determined according to different shapes in a predetermined order.

Fig. 8 illustrates a process performed by the image decoding equipment 100 for determining that the current coding unit should be split into an odd number of coding units when the coding units are not preprocessed according to an embodiment.

According to an embodiment, the image decoding equipment 100 can determine that the current coding unit is to be split into an odd number of coding units based on the received mode information according to the split shape. Referring to FIG. 8, the square first coding unit 800 may be split into non-square second coding units 810a and 810b, and the second coding units 810a and 810b may be independently split into third coding units 820a and 820b and 820c, 820d and 820e. According to an embodiment, the image decoding equipment 100 may determine a plurality of third coding units 820a and 820b by splitting the left second coding unit 810a in the horizontal direction, and may split the right second coding unit 810b into an odd number of third coding units 820c, 820d, and 820e.

According to an embodiment, the video decoding equipment 100 can determine whether or not any coding unit is split into an odd number of coding units by determining whether or not the third coding units 820a and 820b and 820c, 820d and 820e are pre-processed. Referring to FIG. 8, the image decoding equipment 100 may determine the third coding units 820a and 820b and 820c, 820d and 820e by recursively splitting the first coding unit 800. The image decoding equipment 100 can determine whether or not any of the first coding unit 800, the second coding units 810a and 810b, and the third coding units 820a and 820b and 820c, 820d and 820e are split into an odd number of coding units based on at least one of the block shape information and the mode information according to the partition shape. For example, the coding unit to the right of the second coding units 810a and 810b may be split into an odd number of third coding units 820c, 820d and 820e. The processing order of the plurality of coding units included in the first coding unit 800 may be a preset order (for example, the Z-scan order 830), and the image decoding equipment 100 may determine whether or not the third coding units 820c, 820d, and 820e satisfy, which are determined by dividing the right second coding unit 810b into an odd number of coding units, a condition for processing in a predetermined order.

According to an embodiment, the image decoding equipment 100 can determine whether or not the third coding units 820a and 820b and 820c, 820d and 820e included in the first coding unit 800 satisfy the condition for pre-order processing, and the condition associated with this is broken or not, at least one of the width and height of the second coding units 810a and 810b is half along the border of the third coding units 820a and 820b and 820c, 820d and 820e. For example, the third coding units 820a and 820b determined when the height of the left second non-square shaped coding unit 810a is split by half can satisfy the condition. It may be determined that the third coding units 820c, 820d, and 820e do not satisfy the condition because the boundaries of the third coding units 820c, 820d, and 820e determined when the right second coding unit 810b is split into three coding units cannot split the width or height of the right second coding units 810b by half. When the condition is not satisfied as described above, the image decoding equipment 100 may determine a scan order discontinuity and may determine that the right second coding unit 810b should be split into an odd number of coding units based on the determination result. According to an embodiment, when a coding unit is partitioned into an odd number of coding units, the image decoding equipment 100 may impose a preset limit on the coding unit at a preset location among the split coding units. The restriction or preset location is described above with respect to the various embodiments, and therefore, detailed descriptions of the meaning are not provided herein.

Fig. 9 illustrates a process performed by the image decoding equipment 100 to determine at least one coding unit by splitting the first coding unit 900, according to an embodiment.

According to an embodiment, the image decoding equipment 100 can split the first coding unit 900 based on the mode information according to the splitting form that is obtained through the bit stream obtaining unit 110 . The square first coding unit 900 may be split into four square coding units, or may be split into multiple non-square coding units. For example, referring to FIG. 9, when the first coding unit 900 is square, and the mode information according to the partition shape indicates a need to split the first coding unit 900 into non-square coding units, the image decoding equipment 100 may split the first coding unit 900 into a plurality of non-square coding units. In detail, when the mode information according to the split shape indicates the need to determine an odd number of coding units by splitting the first coding unit 900 in the horizontal direction or in the vertical direction, the image decoding equipment 100 may split the square first coding unit 900 into an odd number of coding units, such as second units. 910a, 910b, and 910c coding determined by splitting the square first coding unit 900 in the vertical direction, or second coding units 920a, 920b, and 920c determined by splitting the square first coding unit 900 in the horizontal direction.

According to an embodiment, the image decoding equipment 100 can determine whether or not the second coding units 910a, 910b, 910c, 920a, 920b, and 920c included in the first coding unit 900 satisfy a condition for processing in a preset order, and the condition is associated with it. , should split or not, at least one of the width and height of the first unit 900 coding half along the boundary of the second unit 910a, 910b, 910c, 920a, 920b and 920c coding. Referring to FIG. 9, since the boundaries of the second coding units 910a, 910b, and 910c determined by splitting the square first coding unit 900 in the vertical direction do not split the width of the first coding unit 900 in half, it can be determined that the first coding unit 900 does not satisfy the condition for pre-processing. in the prescribed manner. In addition, since the boundaries of the second coding units 920a, 920b, and 920c determined by splitting the square first coding unit 900 in the horizontal direction do not split the height of the first coding unit 900 in half, it can be determined that the first coding unit 900 does not satisfy the condition for processing in predetermined order. When the condition is not satisfied as described above, the image decoding equipment 100 may determine a scan order discontinuity and may determine that the first coding unit 900 should be split into an odd number of coding units based on the decision result. According to an embodiment, when a coding unit is split into an odd number of coding units, the image decoding equipment 100 may impose a preset limit on the coding unit at a preset location from among the split coding units. The limitation or preset location is described above with respect to the various embodiments, and therefore, detailed descriptions of the meaning are not provided herein.

According to an embodiment, the image decoding equipment 100 can determine different shape coding units by splitting the first coding unit.

Referring to FIG. 9, the image decoding equipment 100 may partition the square first coding unit 900 or the non-square first coding unit 930 or 950 into different shaped coding units.

Fig. 10 illustrates that the shape into which the second coding unit is split is limited when the second coding unit having a non-square shape, which is determined when the image decoding equipment 100 splits the first 1000 coding unit, satisfies a predetermined condition, according to an embodiment.

According to an embodiment, the image decoding equipment 100 may determine whether to split the square first coding unit 1000 into non-square second coding units 1010a and 1010b or 1020a and 1020b coding, based on the mode information according to the split shape that is obtained by the bit stream obtaining unit 110. The second coding units 1010a and 1010b or 1020a and 1020b may be independently split. In this regard, the image decoding equipment 100 may determine whether or not to split each of the second coding units 1010a and 1010b or 1020a and 1020b into a plurality of coding units based on the mode information according to the split shape of each of the second units 1010a and 1010b or 1020a, and 1020b encoding. According to an embodiment, the image decoding equipment 100 can determine the third coding units 1012a and 1012b by splitting the non-square left second coding unit 1010a, which is determined by splitting the first coding unit 1000 in the vertical direction, in the horizontal direction. However, when the left second coding unit 1010a is split in the horizontal direction, the image decoding equipment 100 may restrict the right second coding unit 1010b so that it is not split in the horizontal direction in which the left second coding unit 1010a is split. When the third coding units 1014a and 1014b are determined by splitting the right second coding unit 1010b in the same direction, since the left and right second coding units 1010a and 1010b are independently split in the horizontal direction, third coding units 1012a and 1012b or 1014a and 1014b may be determined. However, this case operates identically to the case in which the image decoding equipment 100 partitions the first coding unit 1000 into four square second coding units 1030a, 1030b, 1030c, and 1030d based on the mode information according to the split shape, and may be inefficient in terms of image decoding.

According to an embodiment, the image decoding equipment 100 may determine the third coding units 1022a and 1022b or 1024a and 1024b by splitting the non-square second coding unit 1020a or 1020b, which is determined by splitting the first coding unit 1000 in the horizontal direction, in the vertical direction. However, when the second coding unit (e.g., upper second coding unit 1020a) is split in the vertical direction, for the reason described above, the image decoding equipment 100 may restrict another second coding unit (e.g., lower second coding unit 1020b) such that it is not split in the vertical direction in which the top second coding unit 1020a is split.

Fig. 11 illustrates a process performed by the image decoding equipment 100 for splitting a square coding unit when mode information according to the split shape indicates that a square coding unit should not be split into four square coding units, according to an embodiment.

According to an embodiment, the image decoding equipment 100 may determine second coding units 1110a and 1110b or 1120a and 1120b, and so on. by splitting the first coding unit 1100 based on the mode information according to the split shape. The mode information according to the partition shape may include information on various partitioning methods of a coding unit, but information on various partitioning methods may not include information for partitioning a coding unit into four square coding units. According to such mode information according to the split shape, the image decoding equipment 100 may not split the square first coding unit 1100 into four square second coding units 1130a, 1130b, 1130c, and 1130d. The image decoding equipment 100 may determine the non-square second coding units 1110a and 1110b or 1120a and 1120b, etc., based on the mode information according to the partition shape.

According to an embodiment, the image decoding equipment 100 can independently split non-square second coding units 1110a and 1110b or 1120a and 1120b coding, etc. Each of the second coding units 1110a and 1110b or 1120a and 1120b, etc. may be recursively split in a predetermined order, and this splitting method may correspond to the splitting method of the first coding unit 1100 based on the mode information according to the split shape.

For example, the image decoding equipment 100 may determine the square third coding units 1112a and 1112b by splitting the left second coding unit 1110a in the horizontal direction, and may determine the square third coding units 1114a and 1114b by splitting the right second coding unit 1110b in the horizontal direction. In addition, the image decoding equipment 100 can determine the square third coding units 1116a, 1116b, 1116c, and 1116d by splitting both of the left and right second coding units 1110a and 1110b in the horizontal direction. In this case, coding units having the same shape as the four square second coding units 1130a, 1130b, 1130c, and 1130d split from the first coding unit 1100 may be determined.

As another example, the image decoding equipment 100 may determine the square third coding units 1122a and 1122b by splitting the upper second coding unit 1120a in the vertical direction, and may determine the square third coding units 1124a and 1124b by splitting the lower second coding unit 1120b in the vertical direction. In addition, the image decoding equipment 100 can determine the square third coding units 1126a, 1126b, 1126c, and 1126d by splitting both of the upper and lower second coding units 1120a and 1120b in the vertical direction. In this case, coding units having the same shape as the four square second coding units 1130a, 1130b, 1130c, and 1130d split from the first coding unit 1100 may be determined.

Fig. 12 illustrates that the processing order between the plurality of coding units may change depending on the coding unit partitioning process according to the embodiment.

According to an embodiment, the image decoding equipment 100 can split the first coding unit 1200 based on the mode information according to the split shape. When the block shape indicates a square shape, and the mode information according to the split shape indicates the need to split the first coding unit 1200 in at least one of the horizontal and vertical directions, the image decoding equipment 100 may determine the second coding units 1210a and 1210b or 1220a and 1220b, and etc. by splitting the first coding unit 1200 . Referring to FIG. 12, non-square second coding units 1210a and 1210b or 1220a and 1220b determined by splitting the first coding unit 1200 only in the horizontal direction or in the vertical direction can be independently split based on the mode information according to the split shape of each coding unit. For example, the image decoding equipment 100 may determine the third coding units 1216a, 1216b, 1216c, and 1216d by splitting the second coding units 1210a and 1210b, which are generated by splitting the first coding unit 1200 in the vertical direction, in the horizontal direction, and may determine the third coding units 1226a, 1226b , 1226c and 1226d coding by splitting the second coding units 1220a and 1220b, which are generated by splitting the first coding unit 1200 in the horizontal direction, in the vertical direction. The operation of splitting the second coding units 1210a and 1210b or 1220a and 1220b is described above with respect to FIG. 11, and as such, detailed descriptions of what is meant are not provided herein.

According to an embodiment, the image decoding equipment 100 can process coding units in a predetermined order. The operation of processing coding units in a preset order is described above with respect to FIG. 7, and as such, detailed descriptions of what is meant are not provided herein. Referring to FIG. 12, the image decoding equipment 100 may determine four square third coding units 1216a, 1216b, 1216c, and 1216d and 1226a, 1226b, 1226c, and 1226d by splitting the square first coding unit 1200. According to an embodiment, the image decoding equipment 100 may determine the processing orders of the third coding units 1216a, 1216b, 1216c, and 1216d and 1226a, 1226b, 1226c, and 1226d based on the split shape by which the first coding unit 1200 is split.

According to an embodiment, the image decoding equipment 100 may determine the third coding units 1216a, 1216b, 1216c, and 1216d by splitting the second coding units 1210a and 1210b generated by splitting the first coding unit 1200 in the vertical direction, in the horizontal direction, and may process the third coding units 1216a , 1216b, 1216c and 1216d coding in the processing order 1217 for initially processing the third coding units 1226a and 1226c that are included in the left second coding unit 1210a in the vertical direction, and then processing the third coding unit 1216b and 1216d that are included in the right second coding unit 1210b encoding, in the vertical direction.

According to an embodiment, the image decoding equipment 100 may determine the third coding units 1226a, 1226b, 1226c, and 1226d by splitting the second coding units 1220a and 1220b generated by splitting the first coding unit 1200 in the horizontal direction, in the vertical direction, and may process the third coding units 1226a , 1226b, 1226c and 1226d coding in the processing order 1227 for initially processing the third coding units 1226a and 1226b that are included in the upper second coding unit 1220a in the horizontal direction, and then processing the third coding unit 1226c and 1226d that are included in the lower second coding unit 1220b encoding, in the horizontal direction.

Referring to FIG. 12, square third coding units 1216a, 1216b, 1216c, and 1216d and 1226a, 1226b, 1226c, and 1226d may be determined by splitting second coding units 1210a and 1210b and 1220a and 1220b, respectively. Although the second coding units 1210a and 1210b are determined by splitting the first coding unit 1200 in the vertical direction differently compared to the second coding units 1220a and 1220b, which are defined by splitting the first coding unit 1200 in the horizontal direction, the third units 1216a, 1216b, 1216c and 1216d and 1226a, 1226b, 1226c and 1226d encodings broken out of it eventually show identical shape coding units broken down from the first encoding unit 1200. In this regard, by recursively splitting a coding unit in various ways based on the mode information according to the split shape, the image decoding equipment 100 can process a plurality of coding units in different orders even when the coding units are ultimately determined to have the same shape.

Fig. 13 illustrates a process for determining the depth of a coding unit as the shape and size of a coding unit change when a coding unit is recursively split such that a plurality of coding units are determined, according to an embodiment.

According to an embodiment, the image decoding equipment 100 can determine the depth of a coding unit based on a predetermined criterion. For example, the predetermined criterion may be the length of the long side of the coding unit. When the length of the long side of the coding unit before splitting is 2n times (n>0) the length of the long side of the splitted current coding unit, the image decoding equipment 100 may determine that the depth of the current coding unit is increased relative to the depth of the coding unit before splitting, by n. In the description below, a coding unit having an increased depth is expressed as a coding unit of a smaller depth.

Referring to FIG. 13, according to an embodiment, the image decoding equipment 100 can determine the second coding unit 1302 and the third coding unit 1304 of smaller depths by splitting the square first coding unit 1300 based on the block shape information indicating a square shape (for example, the block shape information can be expressed as "0 : square"). Assuming that the size of the square first coding unit 1300 is 2Nx2N, the second coding unit 1302, determined by dividing the width and height of the first coding unit 1300 by 1/2, may have a size of NxN. In addition, the third coding unit 1304, determined by dividing the width and height of the second coding unit 1302 by 1/2, may have a size of N/2xN/2. In this case, the width and height of the third coding unit 1304 is 1/4 of the width and height of the first coding unit 1300. When the depth of the first coding unit 1300 is D, the depth of the second coding unit 1302, whose width and height are 1/2 of the width and height of the first coding unit 1300, may be D+1, and the depth of the third coding unit 1304, whose width and height are 1/4 with respect to the width and height of the first coding unit 1300 may be D+2.

According to an embodiment, the image decoding equipment 100 may determine the second coding unit 1312 or 1322 and the third lower depth coding unit 1314 or 1324 by splitting the non-square first coding unit 1310 or 1320 based on block shape information indicating a non-square shape (e.g., block shape information may expressed as "1: NS_VER" indicating a non-square shape whose height exceeds the width, or as "2: NS_HOR" indicating a non-square shape whose width exceeds the height).

The image decoding equipment 100 may determine the second coding unit 1302, 1312, or 1322 by splitting at least one of the width and height of the first coding unit 1310 having a size of Nx2N. Thus, the image decoding equipment 100 may determine a second coding unit 1302 having a size of NxN, or a second coding unit 1322 having a size of NxN/2, by splitting the first coding unit 1310 in the horizontal direction, or may determine the second coding unit 1312, having a size in N/2xN by splitting the first coding unit 1310 in the horizontal and vertical directions.

According to an embodiment, the image decoding equipment 100 may determine the second coding unit 1302, 1312, or 1322 by splitting at least one of the width and height of the first coding unit 1320 having a size of 2NxN. Thus, the image decoding equipment 100 may determine a second coding unit 1302 having a size of NxN, or a second coding unit 1312 having a size of N/2xN, by splitting the first coding unit 1320 in the vertical direction, or may determine the second coding unit 1322, having a size in NxN/2, by splitting the first coding unit 1320 in the horizontal and vertical directions.

According to an embodiment, the image decoding equipment 100 may determine the third coding unit 1304, 1314, or 1324 by splitting at least one of the width and height of the second coding unit 1302 having a size of NxN. Thus, the image decoding equipment 100 may determine a third coding unit 1304 having a size of N/2xN/2, a third coding unit 1314 having a size of N/4xN/2, or a third coding unit 1324 having a size of N/2xN/ 4 by splitting the second coding unit 1302 in the vertical and horizontal directions.

According to an embodiment, the image decoding equipment 100 may determine the third coding unit 1304, 1314, or 1324 by splitting at least one of the width and height of the second coding unit 1312 having a size of N/2xN. Thus, the image decoding equipment 100 may determine a third coding unit 1304 having a size of N/2xN/2 or a third coding unit 1324 having a size of N/2xN/4 by splitting the second coding unit 1312 in the horizontal direction, or may determine a third coding unit 1314 having a size of N/4xN/2 by splitting the second coding unit 1312 in the vertical and horizontal directions.

According to an embodiment, the image decoding equipment 100 may determine the third coding unit 1304, 1314, or 1324 by splitting at least one of the width and height of the second coding unit 1322 having a size of NxN/2. Thus, the image decoding equipment 100 may determine a third coding unit 1304 having a size of N/2xN/2 or a third coding unit 1314 having a size of N/4xN/2 by splitting the second coding unit 1322 in the vertical direction, or may determine a third coding unit 1324 having a size of N/2xN/4 by splitting the second coding unit 1322 in the vertical and horizontal directions.

According to an embodiment, the image decoding equipment 100 may partition a square coding unit 1300, 1302, or 1304 in a horizontal or vertical direction. For example, the image decoding equipment 100 may determine the first coding unit 1310 having a size of Nx2N by splitting the first coding unit 1300 having a size of 2Nx2N in the vertical direction, or may determine the first coding unit 1320 having a size of 2NxN by splitting the first coding units 1300 in the horizontal direction. According to an embodiment, when the depth is determined based on the length of the longest side of the coding unit, the depth of the coding unit determined by splitting the first coding unit 1300 having a size of 2Nx2N in the horizontal or vertical direction may be identical to the depth of the first coding unit 1300.

According to an embodiment, the width and height of the third coding unit 1314 or 1324 may be 1/4 of the width and height of the first coding unit 1310 or 1320. When the depth of the first coding unit 1310 or 1320 is D, the depth of the second coding unit 1312 or 1322 whose width and height is 1/2 of the width and height of the first coding unit 1310 or 1320 may be D+1, and the depth of the third coding unit 1314 or An encoding 1324 whose width and height is 1/4 of the width and height of the first encoding unit 1310 or 1320 may be D+2.

Fig. 14 illustrates depths that are definable based on shapes and sizes of coding units and part indices (PIDs) for distinguishing coding units, according to an embodiment.

According to an embodiment, the image decoding equipment 100 can determine second coding units of different shapes by splitting the square of the first coding unit 1400. Referring to FIG. 14, the image decoding equipment 100 can determine the second encoding units 1402a and 1402b, 1404a and 1404b and 1406a, 1406b, 1406c and 1406d by splitting the first encoding unit 1400 in at least one of the vertical and horizontal directions based on the mode information according to the form partitions. Thus, the image decoding equipment 100 can determine the second coding units 1402a and 1402b, 1404a and 1404b and 1406a, 1406b, 1406c and 1406d, based on the mode information according to the split shape of the first coding unit 1400.

According to an embodiment, the depths of the second coding units 1402a and 1402b, 1404a and 1404b and 1406a, 1406b, 1406c and 1406d, which are determined based on the mode information according to the split shape of the square first coding unit 1400, may be determined based on the length of their long side. For example, since the side length of the square first coding unit 1400 is equal to the length of the long side of the non-square second coding units 1402a and 1402b and 1404a and 1404b coding, the first coding unit 1400 and the non-square second coding units 1402a and 1402b and 1404a and 1404b coding may have the same depth, for example, D However, when the image decoding equipment 100 splits the first coding unit 1400 into four square second coding units 1406a, 1406b, 1406c, and 1406d based on the mode information according to the split shape, since the side length of the square second coding units 1406a, 1406b, 1406c, and 1406d is 1/2 of the side length of the first coding unit 1400, the depth of the second coding units 1406a, 1406b, 1406c, and 1406d may be D+1, which is greater than the depth D of the first coding unit 1400 by 1.

According to an embodiment, the image decoding equipment 100 can determine a plurality of second coding units 1412a and 1412b and 1414a, 1414b and 1414c by splitting the first coding unit 1410 whose height exceeds the width in the horizontal direction based on the mode information according to the split shape. According to an embodiment, the image decoding equipment 100 can determine a plurality of second coding units 1422a and 1422b and 1424a, 1424b and 1424c by splitting the first coding unit 1420 whose width exceeds the height in the vertical direction based on the mode information according to the split shape.

According to an embodiment, the depth of the second coding units 1412a and 1412b and 1414a, 1414b and 1414c or 1422a and 1422b and 1424a, 1424b and 1424c, which is determined based on the mode information according to the split shape of the non-square first coding unit 1410 or 1420, may be determined based on the length their long side. For example, since the length of the side of the square second coding units 1412a and 1412b is 1/2 relative to the length of the long side of the first coding unit 1410 having a non-square shape whose height exceeds the width, the depth of the square second coding units 1412a and 1412b is D+1, which is greater than the depth D non-square first coding unit 1410 by 1.

In addition, the image decoding equipment 100 can partition the non-square first coding unit 1410 into an odd number of second coding units 1414a, 1414b, and 1414c based on the mode information according to the split shape. An odd number of second coding units 1414a, 1414b, and 1414c may include non-square second coding units 1414a and 1414c and a square second coding unit 1414b. In this case, since the long side length of the non-square second coding units 1414a and 1414c and the side length of the square second coding unit 1414b are 1/2 of the long side length of the first coding unit 1410, the depth of the second coding units 1414a, 1414b, and 1414c may be D+1 , which is greater than the depth D of the non-square first coding unit 1410 by 1. The image decoding equipment 100 can determine the depths of coding units split from the first coding unit 1420 having a non-square shape whose width exceeds the height by using the above-described method for determining the depths of coding units split from the first unit 1410 coding.

According to an embodiment, the image decoding equipment 100 can determine a PID for identifying split coding units based on a size ratio between coding units when an odd number of split coding units do not have equal sizes. Referring to FIG. 14, a center location coding unit 1414b of an odd number of split coding units 1414a, 1414b, and 1414c may have a width equal to the width of the other coding units 1414a and 1414c and a height that is twice the height of the other coding units 1414a and 1414c. Thus, in this case, the coding unit 1414b at the central location may include two of the other coding unit 1414a or 1414c. Therefore, when the PID of the coding unit 1414b at the central location is 1 based on the scan order, the PID of the coding unit 1414c adjacent to the coding unit 1414b may increase by 2, and thus may be 3. Thus, discontinuity in PID values may be present. According to an embodiment, the image decoding equipment 100 can determine whether or not an odd number of split coding units have equal sizes based on whether or not a discontinuity is present in the PID to identify split coding units.

According to an embodiment, the image decoding equipment 100 can determine whether or not to use a particular splitting method based on PID values to identify a plurality of coding units determined by splitting the current coding unit. Referring to FIG. 14, the image decoding equipment 100 may determine an even number of coding units 1412a and 1412b or an odd number of coding units 1414a, 1414b and 1414c by splitting the first coding unit 1410 having a rectangular shape whose height exceeds the width. The image decoding equipment 100 may use the PIDs indicating the respective coding units so as to identify the respective coding units. According to an embodiment, the PID may be derived from a sample at a predetermined location of each coding unit (eg, top left sample).

According to an embodiment, the image decoding equipment 100 can determine a coding unit at a preset location from among the split coding units by using a PID to distinguish between coding units. According to an embodiment, when the mode information according to the split shape of the first coding unit 1410 having a rectangular shape whose height exceeds the width indicates the need to split the coding unit into three coding units, the image decoding equipment 100 may split the first coding unit 1410 into three units 1414a, 1414b and 1414c encoding. The image decoding equipment 100 may assign a PID to each of the three coding units 1414a, 1414b, and 1414c. The image decoding equipment 100 may compare the PIDs of an odd number of split coding units to determine a coding unit at a central location from among the coding units. The image decoding equipment 100 may determine the coding unit 1414b having the PID corresponding to the average of the coding unit PIDs as the coding unit at the central location from among the coding units determined by splitting the first coding unit 1410. According to an embodiment, the image decoding equipment 100 may determine a PID for distinguishing split coding units based on a size ratio between coding units when the split coding units do not have equal sizes. Referring to FIG. 14, a coding unit 1414b generated by splitting the first coding unit 1410 may have a width equal to the width of the other coding units 1414a and 1414c and a height that is twice the height of the other coding units 1414a and 1414c. In this case, when the PID of the coding unit 1414b at the central location is 1, the PID of the coding unit 1414c adjacent to the coding unit 1414b may be increased by 2, and thus may be 3. When the PID is not uniformly increased as described above, the image decoding equipment 100 may determine that a coding unit is partitioned into a plurality of coding units including a coding unit having a size different from that of other coding units. According to an embodiment, when the mode information according to the split form indicates a need to split a coding unit into an odd number of coding units, the image decoding equipment 100 can split the current coding unit such that a preset location coding unit of an odd number of coding units (for example, a central coding unit location) has a different size than other coding units. In this case, the image decoding equipment 100 can determine the coding unit of the central location, which has a different size, by using the PID of the coding units. However, the PID and the size or location of the coding unit of the preset location are not limited to the above-described examples, and different PIDs and different locations and sizes of the coding units may be used.

According to an embodiment, the image decoding equipment 100 may use a preset data unit at which the coding unit starts to split recursively.

Fig. 15 illustrates that a plurality of coding units are determined based on a plurality of preset data units included in a frame, according to an embodiment.

According to an embodiment, a preset data unit may be set as a data unit at which a coding unit starts to recursively split by using mode information according to a split shape. Thus, the preset data unit may correspond to the uppermost depth coding unit, which is used to determine the plurality of coding units split from the current frame. In the following description, for convenience of explanation, the preset data unit is referred to as the reference data unit.

According to an embodiment, the reference data unit may have a preset size and a preset shape. According to an embodiment, the reference data unit may include MxN samples. Here, M and N may be equal to each other and may be integers expressed as powers of 2. Thus, a reference data unit may be square or non-square and may be subdivided into an integer number of coding units.

According to an embodiment, the image decoding equipment 100 may partition the current frame into a plurality of reference data units. According to an embodiment, the image decoding equipment 100 can split a plurality of reference data units that are split from the current frame by using mode information according to the split shape of each reference data unit. The split operation of the reference data unit may correspond to the split operation using a quadtree structure.

According to an embodiment, the image decoding equipment 100 may predetermine a minimum size allowed for reference data units included in the current frame. Accordingly, the image decoding equipment 100 can determine different reference data units having sizes equal to or greater than the minimum size, and can determine one or more coding units by using mode information according to a split shape with reference to the specific reference data unit.

Referring to FIG. 15, the image decoding equipment 100 may use a square coding reference unit 1500 or a non-square coding reference unit 1502. According to an embodiment, the shape and size of reference coding units may be determined based on various data units allowing the inclusion of one or more reference coding units (e.g., sequences, frames, slices, slice segments, tiles, tile groups, largest coding units, etc. .).

According to an embodiment, the bitstream acquisition unit 110 of the image decoding equipment 100 can obtain, from the bitstream, at least one of coding reference unit shape information or coding reference unit size information with respect to each of the various data units. The operation of splitting the square reference coding unit 1500 into one or more coding units is described above with respect to the operation of splitting the current coding unit 300 of FIG. 3, and the operation of splitting the non-square reference coding unit 1502 into one or more coding units is described above with respect to the operation of splitting the current coding unit 400 or 450 of FIG. 4. Thus, detailed descriptions of what is meant are not provided in this document.

According to an embodiment, the image decoding equipment 100 may use the PID to identify the size and shape of the coding reference units to determine the size and shape of the coding reference units according to some data units predetermined based on a predetermined condition. Thus, the bitstream deriving unit 110 can obtain, from the bitstream, only a PID for identifying the size and shape of the reference coding units with respect to each slice, slice segment, tile, tile group, or largest coding unit, which is a data unit satisfying a preset condition (eg, a data unit having a size equal to or smaller than a slice), from various data units (eg, sequences, frames, slices, slice segments, tiles, tile groups, largest coding units, etc.). The image decoding equipment 100 can determine the size and shape of the reference data units with respect to each data unit that satisfies a predetermined condition by using the PID. When the shape information of the reference coding units and the size information of the reference coding units are obtained and used from the bitstream according to each data unit having a relatively small size, the utilization efficiency of the bitstream may not be high, and thus only the PID may be obtained and used instead of directly obtaining coding reference unit shape information; and coding reference unit size information. In this case, at least one of the size and shape of the coding reference units corresponding to the PID for identifying the size and shape of the coding reference units may be predetermined. Thus, the image decoding equipment 100 can determine at least one of the size and shape of the coding reference units included in the data unit serving as the unit for obtaining the PID by selecting at least one of the predetermined size and shape reference coding units based on the PID.

According to an embodiment, the image decoding equipment 100 may use one or more reference coding units included in the largest coding unit. Thus, the largest coding unit split from a frame may include one or more reference coding units, and the coding units may be determined by recursively splitting each reference coding unit. According to an embodiment, at least one of the width and height of the largest coding unit may be an integer number of times at least one of the width and height of the reference coding units. According to an embodiment, the size of the reference coding units may be obtained by partitioning n times the largest coding unit based on a quadtree structure. Thus, the image decoding equipment 100 can determine the reference coding units by splitting n times the largest coding unit based on the quadtree structure, and can split the reference coding unit based on at least one of the block shape information and the mode information according to the split shape according to various embodiments.

According to an embodiment, the image decoding equipment 100 may obtain block shape information indicating the shape of the current coding unit or split shape mode information indicating the splitting method of the current coding unit from the bitstream, and may use the obtained information. The mode information according to the split form may be included in the bit stream associated with various data units. For example, the image decoding equipment 100 may use mode information according to the split shape included in a sequence parameter set, a frame parameter set, a video parameter set, a slice header, a slice segment header, a tile header, or a tile group header. In addition, the image decoding equipment 100 can obtain, from the bitstream, a syntax element corresponding to block shape information or mode information according to the partition shape according to each largest coding unit, each largest coding unit, or each reference coding unit, and can use the obtained syntax element.

Hereinafter, this document describes in detail a method for determining a partitioning rule, according to an embodiment of the disclosure.

The image decoding equipment 100 may determine an image splitting rule. The split rule may be predetermined between the image decoding equipment 100 and the image encoding equipment 200 . The image decoding equipment 100 may determine an image splitting rule based on information obtained from the bit stream. The image decoding equipment 100 may determine a split rule based on information obtained from at least one of a sequence parameter set, a frame parameter set, a video parameter set, a slice header, a slice segment header, a tile header, and a tile group header. The image decoding equipment 100 may determine the split rule differently according to movie frames, slices, tiles, time layers, largest coding units, or coding units.

The image decoding equipment 100 may determine a split rule based on the shape of the coding unit block. The block shape may include the size, shape, width-to-height ratio, and direction of the coding unit. The image encoding equipment 200 and the image decoding equipment 100 may predetermine whether to determine a partitioning rule based on the shape of the coding unit block. However, embodiments of the disclosure are not limited to this. The image decoding equipment 100 may determine a partitioning rule based on information obtained from the bit stream received from the image encoding equipment 200 .

The shape of the coding unit may include square and non-square. When the width and height lengths of the coding unit are identical, the image decoding equipment 100 may determine the shape of the coding unit to be square. In addition, when the width and height lengths of the coding unit are not identical, the image decoding equipment 100 may determine the shape of the coding unit to be non-square.

The coding unit size may include various sizes such as 4x4, 8x4, 4x8, 8x8, 16x4, 16x8, and up to 256x256. The size of a coding unit may be classified based on the length of the long side of the coding unit, the length of the short side, or the area. The image decoding equipment 100 may apply the same partitioning rule to the coding units classified as the same group. For example, the image decoding equipment 100 may classify coding units having identical long side lengths as having the same size. In addition, the image decoding equipment 100 may apply the same partitioning rule to coding units having identical long side lengths.

The width-to-height ratio of the coding unit may include 1:2, 2:1, 1:4, 4:1, 1:8, 8:1, 1:16, 16:1, 32:1, 1:32, and etc. In addition, the direction of the coding unit may include a horizontal direction and a vertical direction. The horizontal direction may indicate the case in which the width length of the coding unit exceeds its height length. The vertical direction may indicate the case in which the width length of the coding unit is less than its height length.

The image decoding equipment 100 can adaptively determine the split rule based on the size of the coding unit. The image decoding equipment 100 may differently determine the allowable mode according to the partition shape based on the coding unit size. For example, the image decoding equipment 100 may determine whether splitting is allowed or not based on the size of the coding unit. The image decoding equipment 100 may determine the splitting direction according to the size of the coding unit. The image decoding equipment 100 may determine the allowable partition type according to the coding unit size.

The split rule determined based on the coding unit size may be a split rule predefined between the image encoding equipment 200 and the image decoding equipment 100 . In addition, the image decoding equipment 100 may determine the splitting rule based on the information obtained from the bitstream.

The image decoding equipment 100 can adaptively determine the split rule based on the location of the coding unit. The image decoding equipment 100 can adaptively determine the split rule based on the location of the coding unit in the image.

In addition, the image decoding equipment 100 can define a partitioning rule such that coding units generated through different partitioning paths do not have the same block shape. However, the embodiment is not limited to this, and coding units generated through different partitioning paths have the same block shape. Encoding units generated via different split paths may have different decoding processing orders. Since the decoding processing orders are described above with reference to FIG. 12, the details of what is meant are not provided again.

Fig. 16 illustrates individual frame coding units when individual frames have different combinations of coding unit split shapes, according to an embodiment.

Referring to FIG. 16, the image decoding equipment 100 can determine various combinations of coding unit split shapes for individual frames. For example, the image decoding equipment 100 may decode an image by using frame 1600, which may be split into four coding units, frame 1610, which may be split into two or four coding units, and frame 1620, which may be split into two, three, or four coding units. from at least one frame included in the image. The image decoding equipment 100 may use only the split shape information indicating the split into four square coding units to split the frame 1600 into a plurality of coding units. The image decoding equipment 100 may only use split shape information indicating split into two or four coding units to split the frame 1610. The image decoding equipment 100 may use only split shape information indicating split into two, three, or four coding units to split the frame. 1620. The above-described partition shape combinations are embodiments for describing the operations of the image decoding equipment 100, and thus the above-described partition shape combinations should not be interpreted as being limited to the above-described embodiments. It should be interpreted that different combinations of split shapes may be used for each preset data unit.

According to an embodiment, the bitstream acquisition unit 110 of the image decoding equipment 100 can acquire a bitstream including an index representing a combination of split shape information for each preset data unit (e.g., sequence, frame, slice, slice segment, tile, tile group etc.). For example, the bitstream obtaining module 110 may obtain an index representing a combination of split shape information from a sequence parameter set, a frame parameter set, a slice header, a tile header, or a tile group header. The bitstream deriving unit 110 of the image decoding equipment 100 may use the obtained index to determine a combination of split shapes into which coding units for each preset data unit may be split, and accordingly, the bitstream deriving unit 110 may use different combinations of split shapes for individual preset units of data.

Fig. 17 illustrates various forms of coding units that can be determined based on mode information according to a split form that can be expressed in binary according to an embodiment.

According to an embodiment, the image decoding equipment 100 can split the coding units into various forms by using block shape information and mode information according to the split shape obtained through the bit stream obtaining unit 110 . The forms into which coding units may be broken down may be various forms, including those described in the embodiments above.

Referring to FIG. 17, the image decoding equipment 100 can split a coding unit having a square shape in at least one direction of a horizontal direction and a vertical direction and a coding unit having a non-square shape in the horizontal direction or in the vertical direction based on the mode information according to splitting form.

According to an embodiment, when the image decoding equipment 100 can partition a coding unit having a square shape in a horizontal direction and a vertical direction to determine four square coding units, the mode information according to the split shape for the square coding unit can represent four split shapes. According to an embodiment, the mode information according to the split shape may be expressed by a 2-digit binary code, and each split shape can be assigned a binary code. For example, when the coding unit is not split, the mode information according to the split shape can be expressed as (00)b when the coding unit is split in the horizontal direction and in the vertical direction, the mode information according to the split shape can be expressed as (01)b when the coding unit is split in the horizontal direction, the mode information according to the split shape can be expressed as (10)b, and when the coding unit is split in the vertical direction, the mode information according to the split shape can be expressed as (11)b.

According to an embodiment, when the image decoding equipment 100 splits a coding unit having a non-square shape in the horizontal direction or in the vertical direction, kinds of split shapes that can be represented by mode information according to the split shape may depend on the number of coding units to be split into coding unit. Referring to FIG. 17, the image decoding equipment 100 can split a coding unit having a non-square shape up to three according to an embodiment. In addition, the image decoding equipment 100 may split a coding unit into two coding units. In this case, the mode information according to the partition form can be expressed as (10)b. The image decoding equipment 100 may partition a coding unit into three coding units. In this case, the mode information according to the partition form can be expressed as (11)b. The image decoding equipment 100 may determine not to split a coding unit. In this case, the mode information according to the partition form can be expressed as (0)b. Thus, the image decoding equipment 100 can use variable length coding (VLC) instead of fixed length coding (FLC) to use a binary code representing mode information according to the split shape.

According to an embodiment, referring to FIG. 17, a mode information binary code according to a split form representing that a coding unit is not split can be expressed as (0)b. In the case in which the mode information binary code according to the split shape representing that the coding unit is not split is set to (00)b, the mode information binary code according to the split shape of 2 bits may be used although there is no shape mode information without splitting, set equal to (01)b. However, in a case in which three split shapes are used for a coding unit having a non-square shape as shown in FIG. 17, the image decoding equipment 100 can determine that the coding unit is not split by using the 1-bit binary code (0)b as mode information according to the split shape, thereby effectively using the bitstream. However, the split shapes of a coding unit having a non-square shape, which are represented by the mode information according to the split shape, should not be interpreted as being limited to the three shapes shown in FIG. 17a are to be interpreted as various forms including the above-described embodiments.

Fig. 18 illustrates other forms of coding units that may be determined based on mode information according to a split form that can be represented with a binary code, according to an embodiment.

Referring to FIG. 18, the image decoding equipment 100 can partition a coding unit having a square shape in a horizontal direction or a vertical direction and a coding unit having a non-square shape in a horizontal direction or a vertical direction based on the mode information according to the split shape. Thus, the mode information according to the split shape can indicate splitting of a coding unit having a square shape in one direction. In this case, a mode information binary code according to a split shape representing that a coding unit having a square shape is not split can be expressed as (0)b. In the case in which the mode information binary code according to the split shape representing that the coding unit is not split is set to (00)b, the mode information binary code according to the split shape of 2 bits may be used although there is no format mode information without splitting, set equal to (01)b. However, in a case in which three split shapes are used for a coding unit having a square shape, as shown in FIG. 18, the image decoding equipment 100 can determine that the coding unit is not split by using the 1-bit binary code (0)b as mode information according to the split shape, thereby effectively using the bit stream. However, the split shapes of a coding unit having a square shape, which are represented by the mode information according to the split shape, should not be interpreted as limited to the three shapes shown in FIG. 18a are to be interpreted as various forms including the above-described embodiments.

According to an embodiment, block shape information or mode information according to the split shape can be expressed by using a binary code, and block shape information or mode information according to the split shape can be generated directly as a bitstream. In addition, the block shape information or mode information according to the partition shape, which can be expressed in binary, can be used as an input binary code in context adaptive binary arithmetic coding (CABAC) instead of being generated directly as a bitstream.

The following describes a process in which the image decoding equipment 100 acquires the syntax for block shape information or mode information according to the partition shape via CABAC, according to the embodiment. The image decoding equipment 100 can acquire a bit stream including a binary code for syntax through the bit stream acquisition unit 110 . The image decoding equipment 100 may debinarize the bit string included in the received bit stream to detect a syntax element representing block shape information or mode information according to the split shape. According to an embodiment, the image decoding equipment 100 can obtain a group of binary strings of bins corresponding to a syntax element to be decoded, and decode individual bins by using probability information. The image decoding equipment 100 may repeat the operation until then, until the bin string configured with the decoded bins is identical to one of the previously received bin strings. The image decoding equipment 100 may perform debinarization on the bin string to determine the syntax element.

According to an embodiment, the image decoding equipment 100 may perform an adaptive binary arithmetic coding decoding process to determine a syntax for a string of binary elements, and the image decoding equipment 100 may update a probability model for the binary elements obtained through the bitstream obtaining unit 110 . Referring to FIG. 17, the bitstream acquisition unit 110 of the image decoding equipment 100 can acquire a bitstream that represents a binary code representing mode information according to a split shape, according to an embodiment. The image decoding equipment 100 can determine the syntax for the mode information according to the split form by using the obtained binary code having a size of 1 or 2 bits. The image decoding equipment 100 may update the probability for each bit of the 2-bit binary code to determine the syntax for the mode information according to the split shape. Thus, the image decoding equipment 100 can update, according to this, that one of 0 or 1 constitutes the value of the first binary element of the 2-bit code, the probability that the next binary element should have a value of 0 or 1 after decoding.

According to an embodiment, in the process of determining the syntax, the image decoding equipment 100 may update the probabilities for the bins that are used in the process of decoding the bins from the bin string for the syntax, and the image decoding equipment 100 may determine that a particular bit of the bin string has identical probability, without updating the probability of a particular bit.

Referring to FIG. 17, in the process of determining the syntax by using the mode information according to the splitting form of a bit string representation for a coding unit having a non-square shape, the image decoding equipment 100 can determine the syntax for the mode information according to the splitting form by using a bit element having a value of 0 in the case, in which the non-square coding unit is not split. Thus, when the block shape information represents that the current coding unit has a non-square shape, the first bin of the bin string for the mode information according to the split shape may be 0 in the case in which the coding unit having a non-square shape is not split, and may be equal to 1 in the case in which the coding unit is split into two or three coding units. Accordingly, the probability that the first bin of the mode information bin string according to the split shape for a coding unit having a non-square shape should be 0 may be 1/3, and the probability that the first bin should be 1, may be 2/3. Since the mode information according to the split shape representing that a coding unit having a non-square shape is not split can be expressed by a 1-bit bin string having a value of 0 as described above, the image decoding equipment 100 can determine that only in the case , in which the first binary element of the mode information according to the partition form is 1, then, the second binary element is 0 or 1 to determine the syntax for the mode information according to the partition form. According to an embodiment, when the first bin for the mode information according to the split shape is 1, the image decoding equipment 100 can determine that the probability that the second bin should be 0 is equal to the probability that the second bin should be 1 , and decode the second binary element.

Accordingly, the image decoding equipment 100 can use, in the process of determining bins from the bin string for mode information according to the split shape, different probabilities for individual bins. According to an embodiment, the image decoding equipment 100 can determine different bin probabilities for mode information according to the split shape according to the width of the current coding unit or the length of the longer side of the current coding unit. According to an embodiment, the image decoding equipment 100 can determine different bin probabilities for the mode information according to the split shape according to at least one of the shape of the current coding unit and the longer side length of the current coding unit. According to an embodiment, the image decoding equipment 100 can determine different bin probabilities for the mode information according to the split shape according to at least one of the shape of the current coding unit and the longer side length of the current coding unit.

According to an embodiment, the image decoding equipment 100 can determine that the bin probabilities for mode information according to the split shape are identical with respect to coding units that are equal to or greater than a preset size. For example, the image decoding equipment 100 may determine that the bin probabilities for the mode information according to the split shape are identical with respect to coding units whose longer side lengths are equal to or greater than 64 samples.

According to an embodiment, the image decoding equipment 100 can determine seed probabilities for the bins constituting the mode information bin string according to the split shape based on the slice type (eg, I-slice, P-slice, or B-slice).

Fig. 19 is a block diagram of an image encoding and decoding system.

An image encoding/decoding system encoder 1900 may transmit an encoded image bitstream, and an image encoding/decoding system decoder 1950 may receive the bitstream and decode the bitstream to output a reconstructed image. Here, the decoder 1950 may be a configuration that is similar to the image decoding equipment 100.

In the encoder 1900, when the prediction mode of the current block is the inter prediction mode, the inter prediction unit 1905 generates motion information of the current block indicating a reference block of a reference frame temporally adjacent to the current frame. Inter-prediction module 1905 may determine the prediction samples of the current block by using the reference block samples. To determine the prediction samples of the current block by using adjacent samples spatially adjacent to the current block, intra-prediction module 1910 may determine intra-prediction information indicating the direction in which adjacent samples similar to the current block are located, or a method for determining predictive samples.

Module 1905 inter-prediction can determine the reference samples to be used to predict the current block, from among the pre-recovered samples stored in the buffer 1948 decoded frames (DPB).

Transformer 1920 outputs transform coefficients by performing transform on residual sample values obtained by subtracting predictive samples generated by inter-prediction module 1905 or intra-prediction module 1910 from the original sample of the current block. A quantizer 1925 quantizes the transform coefficients output by the transform 1920 to output the quantized transform coefficients. Entropy encoder 1930 may encode the quantized transform coefficients into residual syntax elements including level values in order to output the quantized transform coefficients in the form of a bitstream.

The quantized transform coefficients output by quantizer 1925 may be inversely quantized and inversely transformed through inverse quantizer 1933 and inverse transformer 1935, and thus residual sample values may be generated again.

The adder adds the residual sample values with the predicted sample values to output the reconstructed sample value. The post-recovery filter 1940 may perform post-recovery filtering on the recovered samples, and the recovered samples updated through the post-recovery filtering may be used as reference sample values for intra-prediction to be performed in intra-prediction module 1910. The post-restoration filter 1940 may perform Hadamard domain filtering or bilateral filtering on the reconstructed sample values.

The in-loop filter 1945 may perform at least one of deblocking filtering and adaptive loop filtering on the reconstructed samples updated via post-restorative filtering. The reconstructed sample values updated through the filtering of the in-loop filter 1945 may be stored in the DPB 1948 and may be used as reference sample values for inter-prediction to be performed by inter-prediction module 1905.

Entropy decoder 1955 of decoder 1950 may parse residual syntax elements including level values by performing entropy decoding on the received bit stream. Entropy decoder 1955 may recover the quantized transform coefficients from the residual syntax elements. An inverse quantizer 1960 may output the transform coefficients by performing inverse quantization on the quantized transform coefficients, and an inverse transform 1965 may output residual sample values by performing an inverse transform on the transform coefficients.

Inter prediction module 1970 of decoder 1950 may determine a reference frame temporally adjacent to the current frame by using the current block motion information parsed by entropy decoder 1955 and may determine the reference block in the reference frame. Inter-prediction module 1970 may determine the prediction samples of the current block by using the reference block samples. Intra-prediction module 1975 of decoder 1950 may determine reference samples spatially adjacent to the current block by using intra-motion information and current block motion information parsed by entropy decoder 1955, and may determine prediction samples of the current block by using certain adjacent samples.

Inter-prediction module 1970 may determine the reference samples to be used to predict the current block from among the pre-recovered samples stored in the decoded frame buffer (DPB) 1990.

An adder 1995 of the decoder 1950 adds the residual sample values to the predicted sample values to output the reconstructed sample value of the current block. Post-recovery filter 1980 of decoder 1950 may perform Hadamard domain filtering or bilateral filtering on the values of the recovered samples. The recovered samples updated through the post-recovery filtering of the post-recovery filter 1980 may be used as reference sample values for intra-prediction to be performed in intra-prediction module 1975.

In-loop filter 1985 of decoder 1950 may perform at least one of deblocking and adaptive loop filtering on the reconstructed samples updated via post-restoration filtering. The reconstructed sample values updated through the filtering of the in-loop filter 1985 may be stored in the DPB 1990 and may be used as reference sample values for inter-prediction to be performed by inter-prediction module 1970.

The various embodiments described above describe operations related to the image decoding method that is performed by the image decoding equipment 100 . Hereinafter, the operations of the image encoding equipment 200 that implements the image encoding method corresponding to the reverse order of the image decoding method through various embodiments will be described in this document.

Fig. 2 is a block diagram of an image encoding equipment 200 capable of encoding an image based on at least one of block shape information and mode information according to a partition shape, according to an embodiment.

Image encoding equipment 200 may include an encoder 220 and a bitstream generator 210 . Encoder 220 may receive an input image and encode the input image. Encoder 220 may encode the input image to obtain at least one syntax element. The syntax element may include at least one of a skip flag, a prediction mode, a motion vector difference, a motion vector prediction method (or index), a quantized transform coefficient, a coded block pattern, a coded block flag, an intra-prediction mode, a forward flag, union flag, delta-QP, reference index, prediction direction, or transformation index. Encoder 220 may determine a context model based on block shape information including at least one of shape, direction, height-width ratio, or coding unit size.

The bitstream generator 210 may generate a bitstream based on the encoded input image. For example, the bitstream generator 210 may generate a bitstream by performing entropy encoding on a syntax element based on a context model. The image encoding equipment 200 may transmit the bit stream to the image decoding equipment 100 .

According to an embodiment, the encoder 220 of the image encoding equipment 200 may determine the shape of the coding unit. For example, a coding unit may have a square shape or a non-square shape, and information representing such a shape may be included in block shape information.

According to an embodiment, encoder 220 may determine the form into which a coding unit is to be partitioned. The encoder 220 may determine the shape of at least one coding unit included in the coding unit, and the bitstream generator 210 may generate a bitstream including mode information according to the split shape, including information regarding the shape of the coding unit.

According to an embodiment, encoder 220 may determine whether or not to split a coding unit. When the encoder 220 determines that the coding unit includes only one coding unit, or that the coding unit is not split, the bitstream generator 210 may generate a bitstream including mode information according to a split shape representing that the coding unit does not break. The encoder 220 may partition a coding unit into a plurality of coding units included in the coding unit, and the bitstream generator 210 may generate a bitstream including mode information according to a partition shape representing that the coding unit is to be partitioned into the plurality of coding units.

According to an embodiment, information representing the number of coding units into which a coding unit is partitioned or the direction in which a coding unit is partitioned may be included in the mode information according to a split shape. For example, the mode information according to the partition shape may represent a partition in at least one direction of a vertical direction and a horizontal direction, or may represent a non- partition.

The image encoding equipment 200 can determine the mode information according to the split shape based on the mode according to the split shape of the coding unit. The image encoding equipment 200 may determine a context model based on at least one of the shape, direction, width-to-height ratio, or size of the coding unit. The image encoding equipment 200 may generate mode information according to a split form for splitting a coding unit as a bitstream based on a context model.

To determine the context model, the image encoding equipment 200 may obtain an arrangement for corresponding at least one of shape, direction, width-to-height ratio, or coding unit size into an index for the context model. The image encoding equipment 200 may obtain an index for a context model based on at least one of the shape, direction, width-to-height ratio, or coding unit size, from the layout. The image encoding equipment 200 may determine a context model based on an index for the context model.

To determine the context model, the image encoding equipment 200 may determine the context model further based on block shape information including at least one of the shape, direction, width-to-height ratio, or size of the surrounding coding unit adjacent to the coding unit. The surrounding coding unit may include at least one of the coding units located at the bottom left side, left side, top left side, top side, top right side, right side, or bottom right side of the coding unit.

To determine the context model, the image encoding equipment 200 may compare the width length of the top surrounding coding unit with the width length of the coding unit. The image encoding equipment 200 may compare the height lengths of the left and right surrounding coding units with the height length of the coding unit. The image encoding equipment 200 may determine a context model based on the results of the comparisons.

The operations of the image encoding equipment 200 include content that is similar to the content of the image decoding equipment 100 described above with reference to FIG. 3-19, and therefore detailed descriptions of what is meant are omitted.

Fig. 20 is a block diagram of the structure of the image decoding equipment 2000 according to the embodiment.

Referring to FIG. 20, the image decoding equipment 2000 may include a bitstream acquisition unit 2010 and a predictive decoder 2030. Predictive decoder 2030 includes a motion vector prediction unit 2032 and a motion vector recovery unit 2034.

The bitstream receiving module 2010 shown in FIG. 20 may correspond to the bit stream acquisition module 110 shown in FIG. 1 and predictive decoder 2030 may correspond to decoder 120 shown in FIG. 1.

The bitstream receiving module 2010 and the predictive decoder 2030, according to an embodiment, may be implemented as at least one processor. The image decoding equipment 2000 may include one or more memories (not shown) for storing input and output data of the bitstream obtaining module 2010 and the predictive decoder 2030. The image decoding equipment 2000 may include a memory controller (not shown) for controlling storage device data inputs and outputs (not shown).

Module 2010 receive bit streams receives a bit stream as a result of encoding a frame. Module 2010 receive bit streams receives syntax elements for decoding a frame from a bit stream. Binary values corresponding to the syntax elements may be included in the bitstream according to the layered frame structure. Module 2010 receiving bit streams can receive syntax elements by entropy decoding of binary values included in the bit stream.

The bitstream may include information regarding the prediction mode of the current block within the current frame. The current block may mean a block of the largest coding unit, coding unit, or transformation unit split from the current frame to be decoded.

The prediction mode of the current block may include an intra prediction mode or an inter prediction mode. As described above, the inter-prediction mode is the recovery mode of the current block from the reference block indicated by the motion vector of the current block in the reference frame.

Predictive decoder 2030 may recover the current block by using intra-prediction or inter-prediction according to the prediction mode of the current block.

In the inter-prediction mode, motion information can be used to reconstruct the current block. The motion information of the current block may include a prediction direction, a reference frame index, and a motion vector of the current block. The prediction direction, the reference frame index, and the motion vector of the current block may be confirmed from information included in the bitstream.

The prediction direction of the current block may be one of a list 0 direction, a list 1 direction, and a dual direction. The prediction direction being the list 0 direction means using the frame included in the list 0 of the reference frames as the reference frame of the list 0 direction, and the prediction direction being the list 1 direction means using the frame included in the list 1 of the reference frames in as the reference frame of the list 1 direction. The prediction direction being the dual direction means using the frame included in the list 0 of the reference frames as the reference frame of the list 0 direction, and using the frame included in the list 1 of the reference frames as the direction reference frame. list 1.

The reference frame index indicates a frame used as the reference frame of the block from among the frames included in the reference frame list 0 and/or the reference frame list 1. According to the reference frame index of the list direction 0, the frame used as the reference frame of list 0 of the reference frames is indicated from among the frames included in the list 0 direction. According to the reference frame index of the list 1 direction, the frame used as the reference frame of list 1 of the reference frames , is indicated from the number of frames included in the direction of list 1.

The motion vector indicates the location of the reference block in the reference frame. The list direction motion vector 0 means a motion vector indicating the reference block in the list direction reference frame 0, and the list direction motion vector 1 means the motion vector indicating the reference block in the list direction reference frame 1.

When the prediction direction of the current block is the list 0 direction, the motion information of the current block includes at least one of information indicating that the prediction direction of the current block is the list 0 direction, a reference frame index of the list 0 direction, and a motion vector of the list direction 0. When the prediction direction of the current block is the list direction 1, the movement information of the current block includes at least one of information indicating that the prediction direction of the current block is the list direction 1, the reference frame index of the list direction 1 and the motion vector of the list direction 1. When the prediction direction of the current block is the dual direction, the motion information of the current block includes at least one of information indicating that the prediction direction of the current block is the dual direction, the index of the reference frame list direction 0, list direction reference frame index 0, list direction motion vector 0, and list direction motion vector 1.

According to an embodiment, when the prediction mode of the current block is the inter prediction mode, the bitstream obtaining unit 2010 can obtain information indicating the prediction direction of the current block and the reference frame index of the current block from the bitstream. Predictive decoder 2030 may obtain the differential motion vector of the current block from the information included in the bit stream and combine the predictive motion vector of the current block with the differential motion vector to obtain the motion vector of the current block.

Predictive decoder 2030 may reconstruct the current block based on the prediction direction, the reference frame index, and the motion vector of the current block.

The following describes in detail the method implemented by the predictive decoder 2030 to obtain the predictive motion vector of the current block.

The motion vector prediction module 2032 according to an embodiment can obtain a predictive motion vector by using the motion vectors of neighboring blocks adjacent to the current block. Neighbor blocks, which are blocks at predetermined locations used to obtain the predictive motion vector of the current block, are included in the current frame along with the current block.

Neighbor blocks may include block A0, block A1, block B0, block B1, and block B2.

The motion vector prediction module 2032 may identify the locations of block A0, block A1, block B0, block B1, and block B2, based on information indicating the availability of left and right blocks relative to the current block.

In a general video codec, decoding in the bitmap direction is performed per frame. In this case, the left block relative to the current block is fully decoded before the current block and is available, and the right block relative to the current block is not fully decoded and not available.

In the disclosure, the direction of decoding blocks split from a frame may be adaptively determined. In other words, encoding efficiency can be improved by decoding some of the blocks split from a frame in the right-to-left direction instead of decoding all the blocks split from a frame in the raster scanning direction. Accordingly, the right block relative to the current block is available, and the left block relative to the current block is not available, or the left and right blocks relative to the current block are available.

The determination as to whether or not the left block and the right block are available may be identical to the determination regarding the availability of the first neighboring block, which is described hereinafter.

The following describes the locations of neighboring blocks, which vary according to the availability of the left and right blocks relative to the current block, with reference to FIG. 21A-21C.

Fig. 21A illustrates the locations of adjacent blocks when the left block relative to the current block 2100 is available.

Neighbor block locations, when a left block relative to the current block 2100 is available, may be identical to the spatial neighbor block locations specified in the HEVC standard.

Referring to FIG. 21A, adjacent blocks may include a left lower corner block A0, a left lower block A1, a right upper corner block B0, a right upper block B1, and a left upper corner block B2 relative to the current block 2100. As shown in FIG. 21A, the lower left block A1 may be positioned on top of the lower left corner block A0, and the upper right block B1 may be positioned to the left of the upper right corner block B0.

Fig. 21B illustrates the locations of adjacent blocks when left and right blocks relative to the current block 2100 are available.

Referring to FIG. 21B, adjacent blocks may include a right upper corner block A0, a left lower block A1, a left upper block B0, a right lower block B1, and a left upper corner block B2 relative to the current block 2100. As shown in FIG. 21B, the upper left corner block B2 may be positioned to the left of the upper left block B0.

Fig. 21C illustrates the locations of adjacent blocks when the right block relative to the current block 2100 is available.

Referring to FIG. 21C, adjacent blocks may include a right lower corner block A0, a right lower block A1, a left upper corner block B0, a left upper block B1, and a right upper corner block B2 relative to the current block 2100. As shown in FIG. 21C, the lower right block A1 may be positioned on top of the lower right corner block A0, and the upper left block B1 may be positioned to the right of the upper left corner block B0.

Locations of adjacent blocks shown in FIG. 21A-21C are merely an example. According to embodiments, the locations of neighboring blocks and the number of neighboring blocks may vary.

The motion vector prediction module 2032 may determine the availability of the left and right blocks relative to the current block and may indicate the locations of neighboring blocks to be used in order to obtain the predictive motion vector of the current block from the information indicating the availability of the left and right blocks relative to the current block.

According to an embodiment, the motion vector predictor 2032 selects the first neighbor block from the information obtained from the bitstream. The first neighboring block may be one of an A0 block, an A1 block, a B0 block, a B1 block, and a B2 block corresponding to the neighboring blocks.

According to an embodiment, the information obtained from the bit stream may be information indicating the resolution of the motion vectors of the current block. The motion vector prediction unit 2032 may confirm information indicating the motion vector resolution of the current block according to the information obtained from the bitstream from among the plurality of predetermined motion vector resolutions, and may select the first neighboring block to obtain the predictive motion vector.

The resolution of motion vectors may mean the accuracy of a pixel location, which may be indicated by a motion vector determined via inter-prediction from among the pixels included in a reference frame (or interpolated reference frame). A motion vector resolution having an N-pixel unit (where N is a rational number) means that the motion vector can have N-pixel unit precision. For example, resolving the motion vectors to 1/4 pixel unit may mean that the motion vector can point to a pixel in 1/4 pixel unit (i.e., sub-pixel unit) in the interpolated reference frame, and resolving the motion vectors to 1- pixel unit may mean that the motion vector may point a pixel to a 1-pixel unit (ie, an integer pixel unit) in the interpolated reference frame. A motion vector resolution allowing a motion vector expression of the current block from among multiple motion vector resolutions may be adaptively determined.

According to an embodiment, the information indicating the motion vector resolution that is obtained from the bit stream may indicate the first neighboring block among neighboring blocks at different locations when indicating one motion vector resolution among multiple motion vector resolutions.

Fig. 22 is a table showing a match-based relationship between indexes of motion vector permissions, motion vector permissions, and neighboring block locations.

Referring to FIG. 22, motion vector resolution and a neighbor block corresponding to the first neighbor block may be determined according to the AMVR index values. For example, when the AMVR index is 0, the resolution of the motion vectors of the current block may be selected as a 1/4 pixel unit (pel), and the first adjacent block may be selected as block A1. When the AMVR index is 1, the resolution of the motion vectors of the current block may be selected as a 1/2-pixel unit (pel), and the first adjacent block may be selected as the B1 block.

In the existing HEVC standard, multiple neighboring blocks are included in a candidate list, and the motion vector of the neighboring block in the candidate list selected from the information signaled via the bitstream is used as the predictive motion vector. However, according to the disclosure, the first neighboring block used to obtain the predictive motion vector of the current block may be indicated according to information obtained from the bit stream, namely, information indicating the resolution of the motion vectors of the current block. Accordingly, special information (eg, mvp_l0_flag and mvp_l1_flag in HEVC) indicating one neighbor block included in the candidate list is not included in the bitstream.

The motion vector prediction unit 2032 determines the availability of the first neighbor block selected according to the information indicating resolution of the motion vectors. In detail, the motion vector prediction module 2032 determines the availability of the first neighbor block according to at least one of whether or not the tile including the first neighbor block is different from the tile including the current block, whether or not the first neighbor block is located. outside the current frame, whether the first neighbor block is predicted by intra-prediction or not, and whether or not the recovery of the first neighbor block is performed.

For example, when any of the following four conditions is satisfied, the motion vector prediction module 2032 may determine that the first neighboring block is not available.

(Condition 1) The tile including the first neighboring block is different from the tile including the current block.

(Condition 2) The first adjacent block is outside the current frame.

(Condition 3) The first neighboring block is not restored.

(Condition 4) The first adjacent block is encoded in intra-prediction mode or intra-block copy (IBC) mode.

The IBC mode searches for a prediction block corresponding to the current block from the current frame. The prediction block can be found through motion estimation relative to the current frame. For example, a prediction block in the current frame may be searched in units of integer pixels, and a positional relationship between the current block and the found prediction block may be reported to the decoder.

According to an embodiment, when it is identified from the information indicating the availability of the first neighbor block that the first neighbor block is available, and the reference frame index of the first neighbor block for the prediction direction identical to the prediction direction of the current block is not the same as a predetermined value (for example, − 1), the motion vector prediction module 2032 may determine that the motion vector of the first neighbor block is available as the predictive motion vector. When the motion vector of the first neighbor block is available as the predictive motion vector, the motion vector prediction module 2032 extracts the predictive motion vector of the current block from the motion vector of the first neighbor block.

Even when it is identified from the information indicating the availability of the first neighbor block that the first neighbor block is not available or the first neighbor block is available, when the reference frame index of the first neighbor block for the prediction direction identical to the prediction direction of the current block is the same as a predetermined value, it may be determined that the motion vector of the first neighboring block is not available as a predictive motion vector. In this case, the motion vector prediction unit 2032 may obtain a default motion vector according to the default motion vector extraction procedure to be described below, and may obtain the predictive motion vector of the current block by using the default motion vector.

When the index of the reference frame of the first neighbor block for the prediction direction identical to the prediction direction of the current block is not the same as a predetermined value, it may mean that there is a first neighbor block motion vector that indicates a reference frame of the prediction direction identical to the prediction direction of the current block. On the other hand, when the reference frame index of the first neighbor block for the prediction direction identical to the prediction direction of the current block is the same as a predetermined value, it may mean that there are no motion vectors of the first neighbor block that indicate the reference frame of the prediction direction identical to the prediction direction. current block.

The first neighbor block reference frame index includes a list 0 direction reference frame index and a list 1 direction reference frame index. The list 0 direction reference frame index value and the list 1 direction reference frame index value may be determined according to the prediction direction of the first neighbor block.

For example, when the prediction direction of the first neighbor block is the list 0 direction, the list 0 direction reference frame index is set as an index value (eg, ref_idx_l0) obtained from the bit stream, and the list 1 direction reference frame index is set as a predetermined value. Because the frames included in the reference frame list have indices 0-n (where n is a natural number), the predetermined value may be a value other than 0-n, such as -1.

When the prediction direction of the first neighbor block is the list 1 direction, the list 1 direction reference frame index is set as an index value (eg, ref_idx_l1) obtained from the bit stream, and the list 0 direction reference frame index is set as a predetermined value.

When the prediction direction of the first neighbor block is the dual direction, the list 0 direction reference frame index and the list 1 direction reference frame index are set as index values (eg, ref_idx_l0 and ref_idx_l1) obtained from the bit stream.

The following describes the case in which the index of the reference frame of the first neighboring block for the same prediction direction as the current block is the same as the predetermined value or is not the same as the predetermined value, with reference to FIG. 23A-23C.

Fig. 23A illustrates a case in which the reference frame index of the first adjacent block in the same prediction direction as the current block is not the same as a predetermined value.

Referring to FIG. 23A, the respective prediction directions of the current block 2312 and the first neighboring block 2314 are the direction of list 0. Accordingly, the motion vector MV of the first neighboring block 2314 indicates a reference block in a reference frame 2330 included in list 0 of the reference frames. The reference frame index of the first neighbor block 2314 in the list 0 direction is set according to information obtained from the bitstream, and the reference frame index of the first neighbor block 2314 in the list 1 direction is set as a predetermined value. Since the reference frame index of the first adjacent block 2314 in the same prediction direction, namely, list 0 direction, with the prediction direction of the current block 2312 is not identical to the predetermined value, the motion vector predictor 2032 obtains the predictive motion vector of the current block 2312 by using the MV vector movement of the first adjacent block 2314.

Similarly, when the respective prediction directions of the current block 2312 and the first neighboring block 2314 are the list 1 direction, since the index of the reference frame of the first neighboring block 2314 in the same prediction direction, namely the list 1 direction, with the prediction direction of the current block 2312 is not identical a predetermined value, the motion vector predictor 2032 obtains the predictive motion vector of the current block 2312 by using the motion vector MV of the first adjacent block 2314.

Fig. 23B illustrates a case in which the reference frame index of the first adjacent block in the same prediction direction as the current block is the same as a predetermined value.

Referring to FIG. 23B, the prediction directions of the current block 2312 are the list 1 direction, and the prediction directions of the first neighbor block 2314 are the list 0 direction. The motion vector MV of the first neighbor block 2314 indicates a reference block in a reference frame 2330 included in the reference frame list 0. The reference frame index of the first neighbor block 2314 in the list 0 direction is set according to information obtained from the bit stream, and the reference frame index of the first neighbor block 2314 in the list 1 direction is set as a predetermined value. Since the index of the reference frame of the first neighboring block 2314 in the same prediction direction, namely the list 1 direction, with the prediction direction of the current block 2312 is identical to the predetermined value, the motion vector predictor 2032 obtains the predictive motion vector of the current block 2312 by using the motion vector of default, which is described below.

Similarly, when the prediction directions of the current block 2312 are the list 0 direction and the prediction directions of the first neighboring block 2314 are the list 1 direction, since the reference frame index of the first neighboring block 2314 in the same prediction direction, namely, the list 0 direction, with the direction prediction of the current block 2312 is identical to the predetermined value, the motion vector predictor 2032 obtains the predictive motion vector of the current block 2312 by using the default motion vector.

Fig. 23C illustrates a case in which, when the prediction direction of the current block is the dual direction, one of the reference frame index of the first neighbor block in the list 0 direction and the reference frame index of the first neighbor block in the list 1 direction is the same as the predetermined value, and the other is not identical to the predefined value.

Referring to FIG. 23C, the prediction directions of the current block 2312 are the dual direction, and the prediction directions of the first neighbor block 2314 are the list 1 direction. The motion vector MV of the first neighbor block 2314 indicates a reference block in a reference frame 2350 included in list 1 of the reference frames. The reference frame index of the first neighbor block 2314 in the list 0 direction is set as a predetermined value, and the reference frame index of the first neighbor block 2314 in the list 1 direction is set according to information obtained from the bitstream. As described above, the prediction direction being the dual direction includes the list 0 direction and the list 1 direction. the current block 2312 towards list 0 by using the default motion vector. Since the reference frame index of the first neighbor block 2314 in the list 1 direction is not identical to the predetermined value, the motion vector predictor 2032 obtains the predictive motion vector of the current block 2312 by using the motion vector MV of the first neighbor block 2314 in the list 1 direction.

When the prediction direction of the current block 2312 is the dual direction, and the prediction direction of the first neighboring block 2314 is the list 0 direction, the motion vector predictor 2032 obtains the prediction motion vector of the current block 2312 in the list 1 direction by using the motion vector MV of the first neighboring block 2314 in direction of list 0 and obtains a predictive motion vector of the current block 2312 in the direction of list 1 by using the default motion vector.

In the disclosure, when the first neighbor block is available and the reference frame index of the first neighbor block in the same prediction direction as the current block is not the same as the predetermined value, it is determined that the motion vector of the first neighbor block is available as the predictive motion vector. The predictive motion vector of the current block is obtained from the motion vector of the first adjacent block.

When it is determined that the motion vector of the first neighbor block is available as the predictive motion vector, only according to such a condition that the first neighbor block is to be available, the predictive motion vector of the first neighbor block is set as the null vector with high probability, namely, (0, 0). In other words, when the first neighbor block is available, but there are no motion vectors of the first neighbor block in the same prediction direction as the current block, the motion vector of the first neighbor block may not be used as the prediction motion vector of the current block. Thus, the predictive motion vector of the current block can be determined as a null vector and thereby becomes a factor that increases the number of bits needed to express the differential motion vector.

In the disclosure, if not only such a condition that the first neighboring block must be available, but also such a condition that the motion vector of the first neighboring block in the prediction direction identical to the prediction direction of the current block must exist, is satisfied, the prediction motion vector of the current block is obtained using the motion vector of the first neighboring block, resulting in a reduction in the number of bits needed to express the differential motion vector.

The following describes the default motion vector extraction process when the motion vector of the first neighboring block is not available as a predictive motion vector.

According to an embodiment, when the motion vector of the first neighbor block is not available as the predictive motion vector, the motion vector predictor 2032 may set the motion vector of the second neighbor block at the predetermined location as the default motion vector. The second neighbor block may be provided in a plurality. In this case, the motion vector of the second neighboring block may be set as the default motion vector by determining the availability of a plurality of second neighboring blocks.

The second adjacent block may correspond to at least one of the adjacent blocks. For example, the second adjacent block may include block A1 and block B1. As another example, the location of the second adjacent block may be different from the locations of block A0, block A1, block B0, block B1, and block B2.

When the second adjacent block includes block A1 and block B1, the locations of block A1 and block B1 may vary according to the accessibility of the left block and right block relative to the current block, as described above. In detail, with reference to FIG. 21A-21C, when a left block relative to the current block is available, block A1 may be located at the upper left side of the current block, and block B1 may be located at the upper right side of the current block. When left and right blocks relative to the current block are available, block A1 may be located at the bottom left side of the current block, and block B1 may be located at the bottom right side of the current block. When the right block relative to the current block is available, block A1 may be located at the bottom right side of the current block, and block B1 may be located at the top left side of the current block.

The motion vector prediction unit 2032 may determine the availability of the A1 block, and when the A1 block is identified as available according to information indicating whether the A1 block is available or not, may determine the motion vector of the A1 block as the default motion vector. When block A1 is not available, the motion vector prediction module 2032 may determine the availability of block B1, and when block B1 is identified as available according to information indicating whether block B1 is available or not, may determine the motion vector of block B1 as the default motion vector. In other words, the motion vector prediction unit 2032 can check whether or not the motion vectors of block A1 and block B1 can be used as the default motion vector in the order "block A1 --> block B1".

The availability of block A1 and the availability of block B1 may be determined based on the above-described four conditions for determining the availability of the first neighboring block.

According to an embodiment, when the second neighbor block is identified as available according to information indicating whether or not the second neighbor block is available, and the index of the reference frame of the second neighbor block in the prediction direction identical to the prediction direction of the current block is the same as the reference frame index of the current block or not is identical to the predetermined value (i.e., when there is a motion vector of the second neighboring block in the prediction direction identical to the prediction direction of the current block), the motion vector prediction unit 2032 may set the motion vector of the second neighboring block as the default motion vector.

When it is identified from the information indicating the availability of the second neighbor block that the second neighbor block is not available, or there are no motion vectors of the second neighbor block in the prediction direction identical to the prediction direction of the current block, the motion vector predictor 2032 may set the motion vector of the block decoded before current block as the default motion vector.

The motion vector prediction module 2032 may determine the motion vector of the first neighboring block or the default motion vector as the predictive motion vector of the current block.

When the motion vector of the first neighboring block is determined as the predictive motion vector, and the reference frame index of the first neighboring block in the same prediction direction as the current block is not the same as the reference frame index of the current block, the motion vector predictor 2032 may update the predictive motion vector of the current block. block by scaling the predictive motion vector of the current block according to the distance between the current frame and the reference frame of the current block and the distance between the current frame and the reference frame of the first adjacent block.

According to an embodiment, when the index of the reference frame of the second adjacent block (or the block decoded before the current block, the block being used to obtain the default motion vector) in the same prediction direction of the current block is the same as the index of the current block's reference frame , the motion vector prediction module 2032 may determine a default motion vector as the predictive motion vector of the current block. When the index of the reference frame of the second adjacent block (or the block decoded before the current block, the block being used to obtain the default motion vector) in the same prediction direction of the current block is not the same as the index of the current block's reference frame, module 2032 motion vector prediction may scale the default motion vector according to the distance between the current frame and the reference frame of the current block and the distance between the current frame and the reference frame of the second neighboring block (or block decoded before the current block), and may determine the scaled default motion vector as predictive motion vector of the current block.

After obtaining the predictive motion vector of the current block, the motion vector prediction module 2032 may adjust the predictive motion vector of the current block when the motion vector resolution of the current block differs from a predetermined motion vector resolution (e.g., a minimum motion vector resolution of a set of motion vector resolutions). The reason for adjusting the predictive motion vector is to ensure that the resolution of the motion vectors of the current block matches the resolution of the predictive motion vector.

In order to adjust the predictive motion vector expressed as a coordinate in the frame interpolated according to the minimum motion vector resolution to the resolution of the motion vectors of the current block, the motion vector predictor 2032 may adjust the predictive motion vector such that the predictive motion vector indicates neighboring pixels instead of the pixel indicated by through the predictive motion vector.

For example, when the minimum resolution of the motion vectors is 1/4 pixel unit and the resolution of the motion vectors of the current block is 1 pixel unit, the motion vector prediction unit 2032 may adjust the predictive motion vector (19, 27) to (20, 28). This is because when the minimum resolution of the motion vectors is 1/4 pixel unit, an integer pixel has a coordinate of (4n, 4m) in the interpolated frame.

According to an embodiment, when adjusting the predictive motion vector according to the resolution of the motion vectors of the current block, the motion vector predictor 2032 may allow the adjusted predictive motion vector to indicate a pixel located in the upper right side of the pixel indicated by the predictive motion vector not yet adjusted. According to another embodiment, the motion vector prediction module 2032 may allow the adjusted predictive motion vector to indicate a pixel located on the upper left side of the pixel indicated by the predictive motion vector not yet adjusted, the pixel located on the lower left side of the pixel indicated by the predictive vector motion not yet adjusted, or a pixel located on the lower right side of the pixel indicated by the predictive motion vector not yet adjusted.

To summarize the above content, according to the embodiment, when the motion vector of the first neighbor block is available as the predictive motion vector, the motion vector of the first neighbor block is determined as the predictive motion vector of the current block. When the index of the reference frame of the first neighboring block in the prediction direction identical to the prediction direction of the current block is not the same as the index of the reference frame of the current block, the predictive motion vector is scaled. When the motion vector resolution of the current block is not identical to the predetermined motion vector resolution of the motion vector resolution set, the predictive motion vector or the scaled predictive motion vector is adjusted according to the motion vector resolution of the current block.

When the motion vector of the first neighboring block is not available as a predictive motion vector, a default motion vector is extracted. When the block reference frame index for the prediction direction identical to the prediction direction of the current block (the block used to derive the default motion vector) is not identical to the reference frame index of the current block, the default motion vector is scaled, and the scaled default motion vector is determined as the predictive motion vector of the current block. When the motion vector resolution of the current block is not identical to the predetermined motion vector resolution of the plurality of motion vector resolutions, the predictive motion vector is adjusted according to the motion vector resolution of the current block.

The motion vector recovery module 2034 obtains the motion vector of the current block by combining the predictive motion vector of the current block with the differential motion vector obtained from the bit stream. The motion vector recovery module 2034 may obtain the motion vector of the current block by summing the predicted motion vector of the current block with the differential motion vector.

The predictive decoder 2030 may recover the current block by inter-predicting the current block according to the prediction direction, the reference frame index, and the motion vector of the current block.

Fig. 24 is a flowchart of a motion vector decoding method according to an embodiment.

In step S2410, the image decoding equipment 2000 determines the availability of the first neighboring block selected according to the information obtained from the bitstream from among the neighboring blocks adjacent to the current block.

According to an embodiment, the information obtained from the bit stream may include information indicating the resolution of the motion vectors of the current block from the plurality of motion vector resolutions.

In step S2420, the image decoding equipment 2000 determines whether or not the first neighboring block is available, and whether or not the motion vector of the first neighboring block exists for a prediction direction identical to the prediction direction of the current block.

In step S2430, when the first neighbor block is available and the motion vector of the first neighbor block for the prediction direction identical to the prediction direction of the current block exists, the image decoding equipment 2000 obtains the prediction motion vector of the current block from the motion vector of the first neighbor block.

In step S2440, when the first neighbor block is not available or the motion vector of the first neighbor block for the prediction direction identical to the prediction direction of the current block does not exist, the image decoding equipment 2000 obtains the prediction motion vector of the current block from the motion vector of the second neighbor block.

As described above, when a second adjacent block is not available, the predictive motion vector of the current block may be obtained from the motion vector of the block decoded before the current block.

In step S2450, the image decoding equipment 2000 obtains the motion vector of the current block by combining the predictive motion vector of the current block with the differential motion vector.

Fig. 25 is a block diagram of a structure of an image encoding equipment 2500 according to an embodiment.

Referring to FIG. 25, the image encoding equipment 2500 includes a predictive encoder 2510 and a bitstream generator 2530. Predictive encoder 2510 may include a motion vector prediction module 2512 and a motion vector encoding module 2514 .

Predictive encoder 2510 may correspond to encoder 220 shown in FIG. 2 and the bitstream generator 2530 may correspond to the bitstream generator 210 shown in FIG. 2.

Predictive encoder 2510 and bitstream generator 2530, according to an embodiment, may be implemented as at least one processor. Image encoding equipment 2500 may include one or more memories (not shown) for storing input and output data of predictive encoder 2510 and bitstream generator 2530. The image encoding equipment 2500 may include a storage device controller (not shown) for controlling data inputs and outputs of the storage device (not shown).

A predictive encoder 2510 encodes a frame according to a prediction mode, and a bitstream generator 2530 generates a bitstream including information generated as a result of encoding the frame.

Predictive encoder 2510 may determine the prediction mode of the current block within the current frame. When the prediction mode of the current block is determined as the inter prediction mode, the bitstream generator 2530 includes motion information of the current block in the bitstream.

The motion vector prediction unit 2512 predicts the motion vector of the current block encoded in the inter-prediction mode.

The motion vector predictor 2512 according to an embodiment may obtain a predictive motion vector by using the motion vectors of neighboring blocks adjacent to the current block. The locations of neighboring blocks are described above, and therefore their detailed description is omitted.

According to an embodiment, motion vector predictor 2512 selects a first neighboring block from a neighboring block. The first neighboring block may be one of an A0 block, an A1 block, a B0 block, a B1 block, and a B2 block corresponding to the neighboring blocks.

According to an embodiment, the motion vector prediction module 2512 may select the first neighboring block associated with the motion vector resolution of the current block from the plurality of motion vector resolutions.

The motion vector predictor 2512 determines the availability of the first neighboring block. In detail, the motion vector prediction module 2512 determines the availability of the first neighbor block according to at least one of whether or not the tile including the first neighbor block is different from the tile including the current block, whether or not the first neighbor block is located. outside the current frame, whether the first neighbor block is predicted by intra-prediction or not, and whether or not the recovery of the first neighbor block is performed.

According to an embodiment, when it is identified from the information indicating the availability of the first neighbor block that the first neighbor block is available and the reference frame index of the first neighbor block for the prediction direction identical to the prediction direction of the current block is not the same as a predetermined value (i.e., when a motion vector of the first neighbor block for a prediction direction identical to the prediction direction of the current block exists), the motion vector predictor 2512 may determine that the motion vector of the first neighbor block is available as a predictive motion vector. The predetermined value may be -1, for example. When the motion vector of the first neighbor block is available as the predictive motion vector, the motion vector prediction module 2512 extracts the predictive motion vector of the current block from the motion vector of the first neighbor block.

When it is identified from the information indicating the availability of the first neighboring block that the first neighboring block is not available, or the reference frame index of the first neighboring block for the prediction direction identical to the prediction direction of the current block is identical to a predetermined value, it can be determined that the motion vector the first neighboring block is not available as a predictive motion vector. In this case, the motion vector predictor 2512 may obtain the predictive motion vector of the current block by using the default motion vector.

According to an embodiment, when the motion vector of the first neighbor block is not available as the predictive motion vector, the motion vector predictor 2512 may set the motion vector of the second neighbor block at a predetermined location as the default motion vector. The second neighbor block may be provided in a plurality. In this case, the motion vector of the second neighboring block may be set as the default motion vector by determining the availability of a plurality of second neighboring blocks.

When the second neighboring block includes block A1 and block B1, the motion vector predictor 2512 may determine the availability of block A1, and when block A1 is identified as available according to information indicating whether or not block A1 is available, may determine the motion vector of block A1 in as the default motion vector. When block A1 is not available, the motion vector predictor 2512 may determine the availability of block B1, and when block B1 is identified as available according to information indicating whether block B1 is available or not, may determine the motion vector of block B1 as the default motion vector. In other words, the motion vector predictor 2512 may check whether or not the motion vectors of block A1 and block B1 can be used as the default motion vector in the order "block A1 --> block B1".

According to an embodiment, when the second neighbor block is identified as available according to information indicating whether or not the second neighbor block is available, and the index of the reference frame of the second neighbor block in the prediction direction identical to the prediction direction of the current block is the same as the reference frame index of the current block or not is identical to the predetermined value (i.e., when there is a motion vector of the second neighboring block in the prediction direction identical to the prediction direction of the current block), the motion vector prediction unit 2512 may set the motion vector of the second neighboring block as the default motion vector.

When it is identified from the information indicating the availability of the second neighbor block that the second neighbor block is not available, or the index of the reference frame of the second neighbor block in the prediction direction identical to the prediction direction of the current block is identical to a predetermined value, the motion vector prediction unit 2512 may set the motion vector of the block encoded before the current block as the default motion vector.

The motion vector predictor 2512 may determine the motion vector of the first neighboring block or the default motion vector as the predictive motion vector of the current block.

When the motion vector of the first neighboring block is determined as the predictive motion vector, and the reference frame index of the first neighboring block in the prediction direction identical to the current block prediction direction is not the same as the reference frame index of the current block, the motion vector predictor 2512 may update the predictive motion vector of the current block. by scaling the predictive motion vector of the current block according to the distance between the current frame and the reference frame of the current block and the distance between the current frame and the reference frame of the first neighboring block.

When the default motion vector is obtained, according to the embodiment, when the reference frame index of the second adjacent block (or the block decoded before the current block, the block being used to obtain the default motion vector) in the same prediction direction as the current block, is the same as the index of the reference frame of the current block, the motion vector predictor 2512 may determine a default motion vector as the predictive motion vector of the current block. When the index of the reference frame of the second adjacent block (or the block decoded before the current block, the block being used to obtain the default motion vector) in the prediction direction identical to the prediction direction of the current block is not identical to the reference frame index of the current block, module 2512 motion vector prediction may scale the default motion vector according to the distance between the current frame and the reference frame of the current block and the distance between the current frame and the reference frame of the second neighboring block (or block decoded before the current block), and may determine the scaled default motion vector as predictive motion vector of the current block.

After the predictive motion vector of the current block is obtained, the motion vector prediction module 2512 may adjust the predictive motion vector of the current block when the motion vector resolution of the current block differs from a predetermined motion vector resolution (e.g., the minimum motion vector resolution of the set of motion vector resolutions) .

The motion vector encoding unit 2514 obtains a differential motion vector between the motion vector of the current block and the predictive motion vector. The motion vector encoding unit 2514 may obtain a differential motion vector by subtracting the predictive motion vector from the motion vector of the current block.

The bitstream generator 2530 generates a bitstream including information indicating a differential motion vector and information indicating a first neighboring block among neighboring blocks. As described above, the information indicating the first neighboring block may be information indicating the resolution of the motion vectors of the current block from the plurality of motion vector resolutions.

Fig. 26 is a flowchart of a motion vector encoding method according to an embodiment.

In step S2610, the image encoding equipment 2500 determines the availability of the first neighboring block selected from neighboring blocks adjacent to the current block. According to an embodiment, the image encoding equipment 2500 may select the first neighboring block corresponding to the resolution of the motion vectors of the current block.

In step S2620, the image encoding equipment 2500 determines whether or not the first neighboring block is available, and whether or not a motion vector of the first neighboring block exists for a prediction direction identical to the prediction direction of the current block.

In step S2630, when the first neighbor block is available and the motion vector of the first neighbor block for the prediction direction identical to the prediction direction of the current block exists, the image encoding equipment 2500 obtains the prediction motion vector of the current block from the motion vector of the first neighbor block.

In step S2640, when the first neighbor block is not available or the motion vector of the first neighbor block for the prediction direction identical to the prediction direction of the current block does not exist, the image encoding equipment 2500 obtains the prediction motion vector of the current block from the motion vector of the second neighbor block.

When a second neighboring block is not available, the predictive motion vector of the current block may be obtained from the motion vector of the block encoded before the current block.

In step S2650, the image encoding equipment 2500 obtains a differential motion vector between the motion vector of the current block and the predictive motion vector, and generates a bit stream including information indicating the differential motion vector and information indicating the first neighboring block. The information indicating the first neighboring block may be information indicating the resolution of the motion vectors of the current block from the plurality of motion vector resolutions.

Fig. 27 and 28 are views for explaining a process for obtaining a predictive motion vector according to the embodiment.

Fig. 27 and 28 illustrate examples of the above described embodiments. In FIG. 27 and 28, LX included in mvpLX and mvLX indicates the prediction direction of the current block. In other words, when the prediction direction of the current block is the L0 direction, X is 0, and when the prediction direction of the current block is the L1 direction, X is 1. When the prediction direction of the current block is the dual direction, X can sequentially have values in 0 and 1.

In S2710, the mvpAvailFlag flag representing the availability of the predictive motion vector is set to 0.

In S2720, the block to be used to obtain the predictive motion vector of the current block is indicated according to amvr_idx information indicating the resolution of the motion vectors of the current block. When the amvr_idx information is 1, block B1 is selected. Block B1 availability is determined. The determination regarding the availability of block B1 may be performed according to the above-described four conditions for determining the availability of the first neighboring block. Fig. 27 only illustrates the process when amvr_idx is 1 to omit redundant description, but blocks at different locations are selected according to the value of amvr_idx. For example, as shown in FIG. 22, a block with which amvr_idx information is associated can be selected.

In S2730, when a block B1 is identified as available from the information availableB1 indicating the availability of block B1, and the index RefIdxLX of the reference frame of the prediction direction block B1 identical to the prediction direction of the current block is not the same as -1, a flag mvpAvailFlag representing the availability of the predictive motion vector is set equal to 1, and the motion vector of block B1 is set as the predictive motion vector mvpLX.

In S2740, when the index refIdxLX of the reference frame of the current block is not identical to the index RefIdxLX[xNbB1][yNbB1] of the reference frame of block B1, the predictive motion vector mvpLX is scaled according to the distScaleFactorLX relation between the distance currPocDiffLX between the current frame and the reference frame RefPicListX[RefIdxLX[xNbB 1][ yNbB1]] of block B1 and the distance targetPocDiffLX between the current frame and the reference frame RefPicListX[refIdxLX] of the current block.

In S2750, when amvr_idx is not equal to 0, namely, when the motion vector resolution of the current block is different from the predetermined motion vector resolution (eg, the minimum motion vector resolution), the predictive motion vector mvpLX is adjusted. When amvr_idx is 0, namely, when the predictive motion vector is obtained from the motion vector of block A1, the predictive motion vector is not adjusted.

Then, referring to FIG. 28, in S2810, when the flag mvpAvailFlag representing the availability of the predictive motion vector is 0, namely, when the block B1 is identified as unavailable from the information availableB1 indicating the availability of the block B1, or the index RefIdxLX[xNbB1][yNbB1] of the reference frame of the prediction direction block B1 , identical to the prediction direction of the current block, is the same as -1, the default motion vector extraction process through S2820-S2890 is performed.

In S2820, the availability of block A1 and the availability of block B1 are determined. The determinations regarding the availability of block A1 and the availability of block B1 may be made according to the above four conditions to determine the availability of the first neighboring block.

In S2830, the X-axis component and the Y-axis component of the DefaultMvLX motion vector are set to 0 by default.

In S2840, when block A1 is identified as available from availableA1 information indicating the availability of block A1, and the index refIdxLX of the reference frame of the current block is the same as the index RefIdxLX[xNbA1][yNbA1] of the reference frame of block A1, the motion vector of block A1 is set as the motion vector along by default.

In S2850, when the condition mentioned in S2840 is not satisfied, block B1 is identified as available from availableB1 information indicating the availability of block B1, and the index refIdxLX of the reference frame of the current block is the same as the index RefIdxLX[xNbB1][yNbB1] of the reference frame of block B1, vector motion block B1 is set as the default motion vector.

In S2860, when the condition mentioned in S2850 is not satisfied, block A1 is identified as available from availableA1 information indicating the availability of block A1, and index RefIdxLX[xNbA1][yNbA1] of the reference frame of block A1 is not the same -1, motion vector of block A1 is set as the default motion vector.

In S2870, when the condition mentioned in S2860 is not satisfied, block B1 is identified as available from availableB1 information indicating the availability of block B1, and index RefIdxLX[xNbB1][yNbB1] of the reference frame of block B1 is not the same -1, motion vector of block B1 is set as the default motion vector.

In S2880, when the motion vector of block A1 or the motion vector of block B1 is not set as the default motion vector, the motion vector of the block decoded before the current block is set as the default motion vector.

In S2890, when the reference frame index refIdxLX of the current block is not identical to the DefaultRefIdxLX index of the default reference frame, the default motion vector is scaled according to the distScaleFactorLX relation between the distance currPocDiffLX between the current frame and the frame RefPicListX[DefaultRefIdxLX] indicated by the DefaultRefIdxLX index of the default reference frame, and the distance targetPocDiffLX between the current frame and the reference frame RefPicListX[refIdxLX] of the current block. The DefaultRefIdxLX index of the default reference frame may mean the index of the reference frame of the block used to obtain the default motion vector.

In S2895, the default motion vector DefaultMvLX is set as the predictive motion vector mvpLX of the current block.

Although not shown in FIG. 28, when amvr_idx is not equal to 0, namely, when the motion vector resolution of the current block is different from the predetermined motion vector resolution (eg, the minimum motion vector resolution), the predictive motion vector mvpLX is adjusted.

The above-described embodiments of the disclosure may be written as computer executable programs, and the written computer executable programs may be stored in a medium.

The medium may continuously store the executable programs or temporarily store the executable programs for execution or loading. In addition, the medium may be any of various recording media or storage media in which a single item or a plurality of hardware items are combined, and the medium is not limited to a medium directly connected to a computer system and can be distributed over a network. Examples of media include magnetic media (such as a hard disk, floppy disk, or magnetic tape), optical media (such as CD-ROM or DVD read only memory), magneto-optical media (such as floppy disk) and ROM, Random Access Memory (RAM), and flash memory, which are configured to store program instructions. hosts, servers, etc. providing or distributing various other types of software.

While one or more embodiments of the disclosure are described with reference to the drawings, those skilled in the art will appreciate that various changes in form and detail may be made without departing from the spirit and scope of the appended claims.

Claims (25)

1. A method for decoding a motion vector by means of an image decoding device, the method comprising the steps of: receiving from the bit stream information indicating the resolution of the motion vectors of the current block; selecting a first neighboring block from a plurality of neighboring blocks adjacent to the current block using information indicating the resolution of motion vectors of the current block; if the current block refers to a reference frame in list 0 and the first neighboring block refers to a reference frame in list 0, determining a motion vector predictor using the motion vector of the first neighboring block; if the current block refers to a reference frame in list 0 and the first neighboring block refers to a reference frame in list 1, determine the default motion vector based on the motion vector of the second neighboring block from the plurality of neighboring blocks adjacent to the current block, and determine the motion vector predictor of the current block using the default motion vector; And determining a motion vector of the current block using said determined motion vector predictor. 2. The method of claim 1, wherein if the first neighbor block is available according to information indicating the availability of the first neighbor block, a motion vector predictor of the current block is obtained using the motion vector of the first neighbor block. 3. The method of claim 2, wherein the accessibility of the first adjacent block is determined according to at least one of whether or not the tile including the first adjacent block differs from the tile including the current block whether or not the first is located. adjacent block outside the current frame, whether the first adjacent block is predicted by intra-prediction or not, and whether or not the first adjacent block is recovered. 4. The method of claim 1, wherein the motion vector resolution is included in a set of motion vector resolutions, wherein the set of motion vector resolutions correspond to neighboring blocks at different locations. 5. The method of claim 1, wherein the location of the second neighbor block is determined based on information indicating the availability of the left neighbor block and the right neighbor block relative to the current block. 6. The method of claim 1, wherein the motion vector of the second neighbor block is determined as the default motion vector if the second neighbor block is available according to information indicating the availability of the second neighbor block, and the second neighbor block refers to a reference frame in list 0. 7. The method of claim 6, wherein the motion vector predictor of the current block is determined using the motion vector of the block decoded before the current block if the second neighbor block is not available or the second neighbor block refers to a reference frame in list 1. 8. An image decoding device, comprising: an acquisition module, configured to obtain from the bit stream information indicating the resolution of the motion vectors of the current block; a motion vector prediction module configured to: select a first neighboring block from a plurality of neighboring blocks adjacent to the current block using information indicating the resolution of the motion vectors of the current block, if the current block refers to a reference frame in list 0 and the first neighboring block refers to a reference frame in list 0, determine the motion vector predictor using the motion vector of the first neighboring block, and if the current block refers to a reference frame in list 0 and the first neighboring block refers to a reference frame in list 1, determine the default motion vector based on the motion vector of the second neighboring block from the set of neighboring blocks adjacent to the current block, and determine the motion vector predictor of the current block using the default motion vector; And a motion vector recovery module, configured to determine the motion vector of the current block using said determined motion vector predictor. 9. A method for encoding a motion vector by means of an image encoding device, the method comprising the steps of: determining the resolution of the motion vectors of the current block; selecting a first neighboring block from a plurality of neighboring blocks adjacent to the current block using motion vector resolution of the current block; if the current block refers to a reference frame in list 0 and the first neighboring block refers to a reference frame in list 0, determining a motion vector predictor using the motion vector of the first neighboring block; if the current block refers to a reference frame in list 0 and the first neighboring block refers to a reference frame in list 1, determine the default motion vector based on the motion vector of the second neighboring block from the plurality of neighboring blocks adjacent to the current block, and determine the motion vector predictor of the current block by using the default motion vector; And generating a bitstream containing information indicating the resolution of the motion vectors of the current block and a differential motion vector determined using the motion vector of the current block and the motion vector predictor of the current block.