RU2806878C2 - Method and device for image encoding/decoding and record medium which stores bitstream - Google Patents

Abstract

FIELD: means for image encoding.

SUBSTANCE: candidate list is generated that includes motion information derived from a spatial neighbour block and a temporal neighbour block adjacent to the current block. The motion information of the current block is derived using the list of candidates. A prediction block of the current block is generated using the derived motion information. The derived motion information in the motion information list is updated, wherein the candidate list is generated to include at least one information from the motion information included in the updated motion information list in the block decoded before the current block.

EFFECT: increased efficiency of compression using a motion information list that stores previously restored motion information.

23 cl, 27 dwg

Description

Field of technology

[0001] The present invention relates to a method and apparatus for encoding/decoding an image and a recording medium for storing a bitstream. More specifically, the present invention relates to a method and apparatus for image encoding/decoding that uses a motion information list storing previously reconstructed motion information.

Prior Art

[0002] Recently, demands for high resolution and high quality images, such as high definition (HD) images and ultra high definition (UHD) images, have increased in various application fields. As the resolution and quality of image data increases, the data volumes increase compared to conventional image data. Therefore, when image data is transmitted using a medium such as a traditional wired/wireless broadband channel or stored using a known storage medium, transmission and storage costs increase. To solve these problems caused by increasing the resolution and quality of image data, a highly efficient image encoding/decoding method is required for an image having high resolution and quality.

[0003] As an image compression method, there are various methods, such as an inter-prediction method for predicting pixel values included in the current picture from a picture before or after the current picture; an intra-prediction method for predicting pixel values included in the current picture using pixel information in the current picture; a conversion and quantization method to compress the energy of the residual signal; and an entropy encoding method to allocate a short code to a value with a high frequency of occurrence and a long code to a value with a low frequency of occurrence. Such image compression technologies can be used to efficiently compress and transmit or store image data.

Disclosure

Technical problem

[0004] An object of the present invention is to provide a method and apparatus for encoding and decoding an image and a recording medium storing a bitstream that improves compression efficiency using a motion information list storing previously reconstructed motion information.

TECHNICAL SOLUTION

[0005] An image decoding method according to an embodiment of the present invention, the method may comprise generating a candidate list including motion information derived from a spatial neighbor block and a temporal neighbor block adjacent to the current block, deriving motion information of the current block using the list candidates, generating a prediction block of the current block using the output motion information, updating the output motion information in the motion information list, wherein generating the candidate list is performed so as to include at least one of the motion information included in the updated motion information list in the block that decoded before the current block.

[0006] In the image decoding method according to the present invention, the motion information list is initialized when decoding of the predetermined area is completed, so that the area changes.

[0007] In the image decoding method according to the present invention, the predefined area is any one of a block composed of one or more coding units (CUs) or a block composed of one or more coding tree units (CTUs).

[0008] In the image decoding method according to the present invention, when there is a plurality of motion information in the updated motion information list in a block decoded before the current block, candidate list generation is performed so as to include the average of at least two or more motion information from lots of information about the movement to the list of candidates.

[0009] In the image decoding method according to the present invention, when the motion information of the updated motion information list in the block decoded before the current block is the same as the motion information previously included in the candidate list, generation of the candidate list is performed in this way to not include the motion information of the motion information list in the candidate list.

[0010] In the image decoding method according to the present invention, when the current block is an IBC prediction mode and the candidate list is a shared merge list, updating the output motion information in the motion information list is omitted.

[0011] In the image decoding method according to the present invention, the motion information list is limited to a predetermined size.

[0012] In the image decoding method according to the present invention, when the amount of motion information stored in the motion information list is a predetermined value, updating the output motion information in the motion information list includes deleting the motion information stored first in the motion information list , and storing the output motion information.

[0013] An image encoding method according to an embodiment of the present invention, wherein the method may comprise generating a candidate list including motion information derived from a spatial neighbor block and a temporal neighbor block adjacent to the current block, deriving motion information of the current block using a candidate list, generating a prediction block of the current block using the output motion information, updating the output motion information in the motion information list, and wherein generating the candidate list is performed so as to include at least one of the motion information included in the updated motion information list in the block , which is encoded before the current block.

[0014] In the image encoding method according to the present invention, the motion information list is initialized when encoding of a predetermined area is completed, so that the area changes.

[0015] In the image encoding method according to the present invention, the predefined area is any one of a block consisting of one or more coding units (CU) or a block consisting of one or more coding tree units (CTU).

[0016] In the image encoding method according to the present invention, when there is a plurality of motion information in the updated motion information list in a block encoded before the current block, generating a candidate list is performed so as to include the average of at least two or more motion information from lots of information about the movement to the list of candidates.

[0017] In the image encoding method according to the present invention, when the motion information of the updated motion information list in the block encoded before the current block is the same as the motion information previously included in the candidate list, generation of the candidate list is performed in this manner to not include the motion information of the motion information list in the candidate list.

[0018] In the image encoding method according to the present invention, when the current block is an IBC prediction mode and the candidate list is a shared merge list, updating the output motion information in the motion information list is omitted.

[0019] In the image encoding method according to the present invention, the motion information list is limited to a predetermined size.

[0020] In the image encoding method according to the present invention, when the amount of motion information stored in the motion information list is a predetermined value, updating the output motion information in the motion information list includes deleting the motion information stored first in the motion information list , and storing the output motion information.

[0021] In a non-transitory computer-readable recording medium containing a bit stream decoded by an image decoding method according to an embodiment of the present invention, the image decoding method may comprise generating a candidate list including motion information derived from a spatial neighbor block and a temporal neighbor block adjacent to the current block, outputting motion information of the current block using the candidate list, generating a prediction block of the current block using the output motion information, updating the output motion information in the motion information list, and wherein generating the candidate list is performed so as to include at least one information from the motion information included in the updated list of motion information in the block decoded before the current block.

USEFUL RESULTS

[0022] The present invention can provide a method and apparatus for encoding and decoding an image and a recording medium storing a bitstream that improves compression efficiency using a motion information list storing previously reconstructed motion information.

[0023] According to the present invention, when there is little motion information or there is no motion information in the motion information list storing the pre-recovered motion information, prediction information can be stored in the motion information list and used to more accurately perform inter-prediction.

[0024] According to the present invention, the efficiency of image encoding and decoding can be improved.

[0025] According to the present invention, the computational complexity of an image encoder and decoder can be reduced.

DESCRIPTION OF DRAWINGS

[0026] FIG. 1 is a block diagram illustrating the configuration of an encoding apparatus in accordance with an embodiment of the present invention.

[0027] FIG. 2 is a block diagram illustrating the configuration of a decoding apparatus in accordance with an embodiment of the present invention.

[0028] FIG. 3 is a diagram schematically illustrating an image division structure in image encoding and decoding.

[0029] FIG. 4 is a diagram illustrating an embodiment of an intra-prediction process.

[0030] FIG. 5 is a diagram illustrating an embodiment of the inter-prediction process.

[0031] FIG. 6 is a diagram illustrating the conversion and quantization process.

[0032] FIG. 7 is a diagram illustrating reference samples available for intra-prediction.

[0033] FIG. 8 and 9 are diagrams illustrating an encoder and a decoder using the motion information list.

[0034] FIG. 10 is a flowchart illustrating an inter-prediction method using a motion information list according to the present invention.

[0035] FIG. 11 is a flowchart illustrating an inter-prediction method using a motion information list.

[0036] FIG. 12 is a flowchart illustrating an inter-prediction method in which motion information list prediction is performed at the motion information list initialization time and the motion information adding time.

[0037] FIG. 13 and 14 are diagrams illustrating an encoder and a decoder including a motion information list predictor.

[0038] FIG. 15 is a diagram illustrating an embodiment of signaling including an indicator indicating whether to apply the motion information list to sequence parameter set (SPS) syntax.

[0039] FIG. 16 is a diagram illustrating an embodiment of signaling including an indicator indicating whether to apply the motion information list to picture parameter set (PPS) syntax.

[0040] FIG. 17 is a diagram illustrating an embodiment of signaling including an indicator indicating whether the motion information list should be applied to the slice header syntax.

[0041] FIG. 18 is a diagram illustrating an example of motion information prediction of a current motion information list from a region temporally adjacent to the current block.

[0042] FIG. 19 is a diagram illustrating an example of motion information prediction of a current motion information list from a region spatially adjacent to the current encoding block.

[0043] FIG. 20 is a diagram illustrating an example of a method for performing prediction of a current motion information list with reference to a motion information list previously recovered by the UPU.

[0044] FIG. 21 is a diagram illustrating a method for performing motion information list prediction from motion information stored in a current motion information list.

[0045] FIG. 22 is a diagram illustrating an example of a process for deriving prediction motion information by changing a reference picture of existing motion information and adjusting the motion vector accordingly.

[0046] FIG. 23 is a diagram illustrating a motion information list prediction method that does not overlap with a motion prediction method candidate.

[0047] FIG. 24 is a diagram illustrating an embodiment of setting a position that is a reference for predicting a motion information list in a CTU when the position of a temporary motion prediction method candidate is the same as positions C and H in FIG. 23.

[0048] FIG. 25 and 26 are diagrams illustrating an embodiment of a method of using predicted motion information and general motion information separately.

[0049] FIG. 27 is a flowchart illustrating an image decoding method according to an embodiment of the present invention.

IMPLEMENTATION mode of the INVENTION

[0050] Many modifications can be made to the present invention, and there are various embodiments of the present invention, examples of which will be presented below and described in detail with reference to the drawings. However, the present invention is not limited to them, although the exemplary embodiments may be construed as including all modifications, equivalents or substitutions in the technical principle and technical scope of the present invention. Like reference numerals refer to the same or similar functions in different aspects. In drawings, shapes and sizes of elements may be exaggerated for clarity. In the following detailed description of the present invention, reference is made to the accompanying drawings, which show, by way of illustration, specific embodiments in which the present invention may be implemented. These embodiments are described in sufficient detail to enable those skilled in the art to implement the present disclosure. The numerous embodiments of the present disclosure, although different, are not necessarily mutually exclusive. For example, specific features, structures, and characteristics described herein in connection with one embodiment may be implemented in other embodiments without departing from the spirit and scope of the present disclosure. Moreover, it should be understood that the location or arrangement of individual elements in each disclosed embodiment may be modified without departing from the spirit and scope of the present disclosure. Therefore, the following detailed description is not to be construed in a limiting sense, and the scope of the present disclosure is determined only by the appended claims, construed as appropriate, together with the full range of equivalents of what is claimed in the claims.

[0051] The terms 'first', 'second', etc. used in the specification. may be used to describe various components, but the components should not be implied to be limited by these terms. These terms are used only to distinguish one component from other components. For example, the 'first' component may be referred to as the 'second' component without departing from the scope of the present invention, and the 'second' component may also likewise be referred to as the 'first' component. The term 'and/or' includes a combination of a plurality of elements or any one of a plurality of elements.

[0052] It should be understood that when an element is merely referred to as being 'connected to' or 'associated with' another element, without being 'directly connected to' or 'directly associated with' the other element in the present specification, it may be 'directly connected to' ' or 'directly associated with' another element or to be connected or associated with another element, having another element intermediate between them. On the contrary, it should be understood that when an element is referred to as “directly connected” or “directly connected” to another element, there are no intermediate elements.

[0053] In addition, the component parts shown in the embodiments of the present invention are shown independently to represent characteristic functions different from each other. Thus, this does not mean that each component part is contained in a separate hardware or software building block. That is, each component includes each of the numbered components for convenience. Thus, at least two component parts of each component part may be combined to form one component part, or one component part may be divided into multiple component parts to perform each function. An embodiment where each component part is combined and an embodiment where one component part is separated are also included within the scope of the present invention unless this leads to a departure from the spirit of the present invention.

[0054] The terms used in this specification are used simply to describe specific embodiments and are not intended to limit the present invention. An expression used in the singular includes an expression in the plural unless it has a clearly different meaning in the context. In this specification, it should be understood that terms such as “including,” “having,” etc. are intended to indicate the presence of the features, quantities, steps, acts, elements, parts, or combinations thereof disclosed in the specification shall not exclude the possibility that one or more other features, quantities, steps, actions, elements, parts or combinations thereof may exist or be added. In other words, when a particular element is referred to as “included,” elements other than the corresponding element are not excluded, but additional elements may be included within embodiments of the present invention or the scope of the present invention.

[0055] In addition, some of the components may not be necessary components that perform the essential functions of the present invention, but are specific components that merely enhance its performance. The present invention can be implemented by including only the components necessary to implement the essence of the present invention, excluding components used to improve performance. A structure including only the necessary components, excluding specific components used only to improve performance, is also included within the scope of the present invention.

[0056] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing exemplary embodiments of the present invention, well-known functions or structures will not be described in detail since they might unnecessarily complicate the understanding of the present invention. Like components in the drawings are designated by the same reference numerals, and repeated description of the same elements will be omitted.

[0057] Further, the image may refer to a picture configuring the video, or may refer to the video itself. For example, “encoding or decoding, or both, of a picture” may mean “encoding or decoding, or both, of a moving picture” and may mean “encoding or decoding, or both of them, one image among the pictures of a moving picture.”

[0058] Further, the terms “moving picture” and “video” may be used to have the same meaning and may be used interchangeably.

[0059] Further, the target image may be an encoding target image, which is an encoding target, and/or a decoding target image, which is a decoding target. Also, the target image may be an input image input to the encoding device and an input image input to the decoding device. Here, the target image can have the same value as the current image.

[0060] Further, the terms “image”, “picture”, “frame” and “screen” can be used to have the same meaning and replace each other.

[0061] Further, the target block may be an encoding target block, which is an encoding target, and/or a decoding target block, which is a decoding target. Also, the target block may be a current block that is the target of the current encoding and/or decoding. For example, the terms “target block” and “current block” can be used to have the same meaning and replace each other.

[0062] Further, the terms “block” and “unit” can be used to have the same meaning and replace each other. Or a “block” may represent a specific unit.

[0063] Further, the terms “region” and “segment” can be used interchangeably.

[0064] Further, the specific signal may be a signal representing a specific block. For example, the source signal may be a signal representing a target block. The prediction signal may be a signal representing a prediction block. The residual signal may be a signal representing a residual block.

[0065] In embodiments, each of specific information, data, flag, index, element and attribute, etc. may matter. An information, data, flag, index, element, and attribute value of “0” may represent a logical “false” or the first predefined value. In other words, the value "0", "false", Boolean "false", and the first predefined value can be used interchangeably. An information, data, flag, index, element, and attribute value of “1” can represent a logical “true” or a second predefined value. In other words, the value "1", "true", Boolean "true", and the second predefined value can be used interchangeably.

[0066] When a variable i or j is used to represent a column, row, or index, the value of i may be an integer equal to or greater than 0, or equal to or greater than 1. That is, column, row, index, etc. can be counted from 0 or can be counted from 1.

[0067]

[0068] Description of terms

[0069] Encoder: means a device that performs encoding. That is, it means an encoding device.

[0070] Decoder: means a device that performs decoding. That is, it means a decoding device.

[0071] Block: is an M×N sample array. Here, M and N can mean positive integers, and block can mean a two-dimensional shaped sampling array. A block can refer to a unit. The current block can mean an encoding target block, which becomes a target when encoding, or a decoding target block, which becomes a target when decoding. In addition, the current block may be at least one of an encoding block, a prediction block, a residual block, and a transform block.

[0072] Sample: represents the basic unit that forms a block. It can be expressed as a value from 0 to 2 ^Bd-1 according to the bit depth (Bd). In the present invention, a sample may be used to designate a pixel. That is, a sample, an image element, a pixel can have the same meaning.

[0073] Unit: May refer to a unit of encoding and decoding. When encoding and decoding an image, a unit may be an area generated by dividing a single image. In addition, a unit can mean a subdivided unit, where one image is divided into subdivided units during encoding or decoding. That is, the image can be divided into many units. When encoding and decoding an image, a predefined process may be performed for each unit. One unit can be divided into sub-units that are smaller than the unit size. Depending on the functions, a unit may mean a block, a macroblock, a coding tree unit, a coding tree block, a coding unit, a coding block, a prediction unit, a prediction block, a residual unit, a residual block, a transform unit, a transform block, etc. In addition, to distinguish a unit from a block, the unit may include a luminance component block, a chroma component block associated with the luminance component block, and a syntax element of each chroma component block. The unit may have various sizes and shapes, in particular, the shape of the unit may be a two-dimensional geometric shape such as a square shape, a rectangular shape, a trapezoidal shape, a triangular shape, a pentagonal shape, etc. In addition, the unit information may include at least one of a unit type indicating a coding unit, a prediction unit, a transformation unit, etc., and a unit size, a unit depth, a unit encoding and decoding sequence, etc.

[0074] Coding tree unit: configured with one coding tree block of the Y luma component and two coding tree blocks related to the Cb and Cr chrominance components. It may also mean that blocks and the syntax element of each block are included. Each coding tree unit may be subdivided using at least one of a quadtree splitting method, a binary tree splitting method, and a ternary tree splitting method to configure a lower unit such as a coding unit, a prediction unit, a transformation unit, etc. This can be used as a term for a sample block that becomes a processing unit when encoding/decoding an image as an input image. Here, quadtree can mean quaternary tree.

[0075] When the encoding block size is within a predetermined range, division is possible using only quadtree partitioning. Here, a predetermined range may be defined as at least one of a maximum size and a minimum encoding block size in which division is possible using only quadtree partitioning. Information indicating the maximum/minimum size of a coding block in which quadtree partitioning is enabled may be signaled by the bitstream, and the information may be signaled in at least one sequence unit, picture parameter, tile group, or slice. Alternatively, the maximum/minimum encoding block size may be a fixed size predefined in the encoder/decoder. For example, when the encoding block size corresponds to 256×256 to 64×64, division is only possible using quadtree partitioning. Alternatively, when the encoding block size is larger than the maximum transform block size, partitioning is only possible using quadtree partitioning. Here, the block to be divided may be at least one of an encoding block and a transform block. In this case, the information indicating splitting of the coded block (eg, split_flag) may be a flag indicating whether or not to perform quadtree splitting. When the encoding block size falls within a predefined range, partitioning is only possible using binary tree or ternary tree partitioning. In this case, the above description of quadtree partitioning can be applied to binary tree partitioning or ternary tree partitioning in the same way.

[0076] Coding tree block: may be used as a term to refer to any one of a Y coding tree block, a Cb coding tree block, and a Cr coding tree block.

[0077] Adjacent block: may mean a block adjacent to the current block. A block adjacent to the current block may mean a block that is in contact with the boundary of the current block, or a block positioned within a predetermined distance from the current block. Adjacent block can mean a block adjacent to the top of the current block. Here, a block adjacent to the top of the current block may mean a block vertically adjacent to an adjacent block that is horizontally adjacent to the current block, or a block horizontally adjacent to an adjacent block that is vertically adjacent to the current block.

[0078] Recovered neighboring block: may mean a neighboring block adjacent to the current block and which has already been spatially/temporally encoded or decoded. Here, a restored neighbor block may mean a restored neighbor unit. The reconstructed spatial neighbor block may be a block within the current picture that has already been reconstructed by encoding or decoding or both. The reconstructed temporary neighboring block is a block in the corresponding position as the current block of the current picture within the reference image or its neighboring block.

[0079] Unit depth: may refer to the degree to which a unit is subdivided. In a tree structure, the highest node (root node) may correspond to the first unit that is not split. Also, the highest node may have the smallest depth value. In this case, the highest node may have a depth of level 0. A node having a depth of level 1 may represent a unit generated by splitting the first unit once. A node having a depth of level 2 can represent a unit generated by splitting the first unit twice. A node having level depth n can represent a unit generated by splitting the first unit n times. A leaf node can be the lowest node and a node that cannot split further. The depth of the leaf node can correspond to the maximum level. For example, the predefined maximum level value could be 3. The root node depth could be the lowest, and the leaf node depth could be the deepest. Additionally, when a unit is expressed as a tree structure, the level at which the unit is present can indicate the depth of the unit.

[0080] Bitstream: may mean a bitstream including image encoding information.

[0081] Parameter set: corresponds to the header information among the configuration in the bitstream. At least one of a video parameter set, a sequence parameter set, a picture parameter set, and an adaptation parameter set may be included in the parameter set. In addition, the set of parameters may include a slice header, a tile group header, and tile header information. The term “tile group” means a group of tiles and has the same meaning as a slice.

[0082] Parsing: can mean determining the meaning of a syntactic element by performing entropy decoding, or can mean entropy decoding itself.

[0083] Symbol: may represent at least one of a syntax element, an encoding parameter, and a conversion factor value of the target encoding/decoding unit. In addition, the symbol can indicate the target of entropy encoding or the result of entropy decoding.

[0084] Prediction mode: may be information indicating an intra-prediction encoded/decoded mode or an inter-prediction encoded/decoded mode.

[0085] Prediction unit: may mean a basic unit when performing prediction such as inter-prediction, intra-prediction, inter-(mutual) compensation, intra-(internal) compensation and motion compensation. One prediction unit may be split into multiple splits having a smaller size, or may be split into multiple smaller prediction units. A plurality of partitions may represent the basic unit when performing prediction or compensation. A partition that is generated by dividing a prediction unit may also be a prediction unit.

[0086] Prediction unit split: may mean a shape obtained by splitting a prediction unit.

[0087] Reference picture list: may refer to a list including one or more reference pictures used for inter-prediction or motion compensation. There are several types of reference picture lists used, including LC (List Concatenated), L0 (List 0), L1 (List 1), L2 (List 2), L3 (List 3).

[0088] Inter-prediction indicator: may refer to the inter-prediction direction (unidirectional prediction, bidirectional prediction, etc.) of the current block. Alternatively, it may refer to the number of reference pictures used to generate the prediction block of the current block. Alternatively, it may refer to the number of prediction blocks used while performing inter-prediction or motion compensation on the current block.

[0089] Prediction List Usage Flag: Indicates whether a prediction block is generated using at least one reference picture in a particular reference picture list. An inter-prediction indicator may be output using a prediction list use flag, and conversely, a prediction list use flag may be output using an inter-prediction indicator. For example, when the prediction list use flag has a first value of zero (0), it means that a reference picture in the reference picture list is not used to generate a prediction block. On the other hand, when the prediction list use flag has a second value of one (1), it means that the reference picture list is used to generate the prediction block.

[0090] Reference picture index: may refer to an index indicating a specific reference picture in a list of reference pictures.

[0091] Reference picture: may refer to a reference picture that is referenced by a particular block for the purposes of inter-prediction or motion compensation of a particular block. Alternatively, the reference picture may be a picture including a reference block referenced by the current block for inter-prediction or motion compensation. Further, the terms “reference picture” and “reference image” have the same meaning and can be used interchangeably.

[0092] Motion vector: may be a two-dimensional vector used for inter-prediction or motion compensation. The motion vector may indicate an offset between a target encoding/decoding block and a reference block. For example, (mvX, mvY) can represent a motion vector. Here, mvX may represent a horizontal component, and mvY may represent a vertical component.

[0093] Search range: may be a two-dimensional region in which a search is performed to extract a motion vector during inter-prediction. For example, the size of the search range may be M×N. Here, M and N are both integers.

[0094] Motion vector candidate: may refer to a prediction candidate block or a motion vector of a prediction candidate block when predicting a motion vector. In addition, the motion vector candidate may be included in the motion vector candidate list.

[0095] Motion vector candidate list: may mean a list composed of one or more motion vector candidates.

[0096] Motion vector candidate index: may mean an index indicating a motion vector candidate in a list of motion vector candidates. Alternatively, it may be a motion vector predictor index.

[0097] Motion information: may mean information including at least one of a motion vector, a reference picture index, an inter-prediction indicator, a prediction list use flag, reference picture list information, a reference picture, a motion vector candidate, motion vector candidate index, fusion candidate, and fusion index.

[0098] Merge candidate list: may mean a list composed of one or more merge candidates.

[0099] Merge candidate: may mean a spatial fusion candidate, a temporal fusion candidate, a fused merge candidate, a fused bi-predictive fusion candidate, or a null fusion candidate. The fusion candidate may include motion information such as an inter-prediction indicator, a reference picture index for each list, a motion vector, a prediction list usage flag, and an inter-prediction indicator.

[00100] Merge index: may mean an index indicating a merge candidate in a list of merge candidates. Alternatively, the merge index may indicate the block from which the merge candidate was derived among reconstructed blocks spatially/temporally adjacent to the current block. Alternatively, the merger index may indicate at least one piece of merger candidate traffic information.

[00101] Transformation unit: may mean a basic unit when performing encoding/decoding, such as transforming, inverse transforming, quantization, dequantization, encoding/decoding of residual signal transform coefficients. One conversion unit can be broken down into many lower level conversion units of smaller size. Here, the transform/inverse transform may comprise at least one of a first transform/first inverse transform and a second transform/second inverse transform.

[00102] Scaling: may refer to the process of multiplying the quantized level by a factor. The conversion factor can be generated by scaling the quantized level. Scaling may also be referred to as dequantization.

[00103] Quantization parameter: may mean a value used when generating a quantized level using a quantization conversion factor. The quantization parameter can also mean the value used when generating the conversion factor by scaling the quantized level during dequantization. The quantization parameter may be a value mapped to a quantization step size.

[00104] Delta quantization parameter: may mean the difference value between the predicted quantization parameter and the quantization parameter of the target encoding/decoding unit.

[00105] Scan: may refer to a method of ordering coefficients within a unit, block, or matrix. For example, the transition from a two-dimensional coefficient matrix to a one-dimensional matrix may be referred to as a scan, and the transition from a one-dimensional coefficient matrix to a two-dimensional matrix may be referred to as a scan or reverse scan.

[00106] Transform coefficient: may refer to the coefficient value generated after performing the transformation in the encoder. It may mean a coefficient value generated after performing at least one of entropy decoding and dequantization in a decoder. The quantized level obtained by quantizing the transform coefficient or residual signal, or the quantized transform coefficient level may also be covered by the semantic value of the transform coefficient.

[00107] Quantized level: may mean the value generated by quantizing the transform coefficient or residual signal in the encoder. Alternatively, the quantized level may mean a value that is a dequantization target for performing dequantization at the decoder. Likewise, the quantized transform coefficient level, which is the result of the transform and quantization, can also be captured by the semantic value of the quantized level.

[00108] Non-zero transform coefficient: may mean a transform coefficient having a value other than zero, or a transform coefficient level or quantized level having a value other than zero.

[00109] Quantization matrix: may refer to a matrix used in a quantization process or a dequantization process performed to improve the subjective or objective quality of an image. The quantization matrix can also be referred to as a scaling list.

[00110] Quantization matrix coefficient: may refer to each element in the quantization matrix. The quantization matrix coefficient may also be referred to as the matrix coefficient.

[00111] Default matrix: may mean a predefined quantization matrix predefined in the encoder or decoder.

[00112] Non-default matrix: may mean a quantization matrix that is not predefined in the encoder or decoder, but is signaled by the user.

[00113] Statistical value: the statistical value for at least one of a variable, encoding parameter, constant value, etc. that has a particular value calculated, may be one or more of an average value, a total value, a weighted average value, a weighted value total value, minimum value, maximum value, most frequent value, median value, interpolated value of the corresponding specific value.

[00114] FIG. 1 is a block diagram showing the configuration of an encoding device in accordance with an embodiment to which the present invention is applicable.

[00115] The encoding device 100 may be an encoder, a video encoding device, or an image encoding device. The video may include at least one image. The encoding device 100 may sequentially encode at least one image.

[00116] With reference to FIG. 1, the encoding device 100 may include a motion prediction module 111, a motion compensation module 112, an intra-prediction module 120, a switch 115, a subtractor 125, a transform module 130, a quantization module 140, an entropy encoding module 150, a dequantization module 160, a module 170 an inverse transform, an adder 175, a filtering module 180, and a reference picture buffer 190.

[00117] The encoding device 100 may encode the input image using intra-mode or inter-mode or both. In addition, the encoding device 100 can generate a bit stream including encoded information by encoding an input image, and output the generated bit stream. The generated bit stream may be stored in a computer-readable recording medium or may be streamed over a wired/wireless transmission medium. When the intra mode is used as the prediction mode, the switch 115 may be switched to the intra mode. Alternatively, when inter mode is used as a prediction mode, switch 115 may be switched to inter mode. Here, intra-mode may mean an intra-prediction mode, and inter-mode may mean an inter-prediction mode. The encoding device 100 may generate a prediction block for an input block of an input image. In addition, the encoding device 100 may encode the residual block using the remainder of the input block and the prediction block after generating the prediction block. The input image may be called the current image, which represents the current encoding target. The input block may be called the current block, which represents the current encoding target, or the encoding target block.

[00118] When the prediction mode is intra-mode, intra-prediction module 120 may use a sample of a block that has already been encoded/decoded and is adjacent to the current block as a reference sample. The intra-prediction module 120 may perform spatial prediction on the current block using a reference sample, or generate prediction samples of the input block by performing spatial prediction. Here, internal (intra) prediction can mean intra-prediction,

[00119] When the prediction mode is inter-mode, the motion prediction unit 111 can extract the region that best matches the input block from the reference image when performing motion prediction, and output a motion vector using the extracted region. In this case, the search area can be used as the mentioned area. The reference picture may be stored in the reference picture buffer 190. Here, when encoding/decoding for a reference picture is completed, it can be stored in the reference picture buffer 190.

[00120] The motion compensation unit 112 can generate a prediction block by performing motion compensation for the current block using a motion vector. Here, inter-prediction may mean inter-prediction or motion compensation.

[00121] When the motion vector value is not an integer, the motion prediction unit 111 and the motion compensation unit 112 can generate a prediction block by applying an interpolation filter to a partial area of the reference picture. To perform inter-picture prediction or motion compensation on a coding unit, it may be determined which mode among the skip mode, merge mode, advanced motion vector prediction (AMVP) mode, and current picture reference mode is used for motion prediction and motion compensation of the prediction unit included in the corresponding coding unit. Then, inter-picture prediction or motion compensation may be performed differently depending on the specific mode.

[00122] Subtractor 125 may generate a residual block using the difference of the input block and the prediction block. The residual block may be called a residual signal. The residual signal may mean the difference between the original signal and the prediction signal. Moreover, the residual signal may be a signal generated by transforming or quantizing, or transforming and quantizing the difference between the original signal and the prediction signal. The residual block may be a residual block unit signal.

[00123] The transformation unit 130 can generate a transformation coefficient by performing transformation on a residual block and output the generated transformation coefficient. Here, the transformation coefficient may be a coefficient value generated by performing transformation of the residual block. When the skip conversion mode is applied, the conversion unit 130 may skip the conversion of the residual block.

[00124] The quantized level can be generated by applying quantization to the transform coefficient or to the residual signal. Further, the quantized level may also be called a conversion coefficient in embodiments.

[00125] The quantization unit 140 can generate a quantized level by quantizing a transform coefficient or a residual signal according to a parameter, and output the generated quantized level. Here, the quantization unit 140 may quantize the transform coefficient using a quantization matrix.

[00126] The entropy encoding unit 150 can generate a bit stream by performing entropy encoding according to a probability distribution on the values calculated by the quantization unit 140 or on the encoding parameter values calculated when performing encoding, and output the generated bit stream. The entropy encoding unit 150 can perform entropy encoding of image sampling information and image decoding information. For example, the image decoding information may include a syntax element.

[00127] When entropy encoding is used, symbols are represented such that fewer bits are assigned to a symbol having a high probability of being generated and a larger number of bits are assigned to a symbol having a low probability of being generated, and thus the size of the bit stream for the symbols to be encoded , may decrease. The entropy coding unit 150 may use a coding method for entropy coding such as exponential Golomb coding, context adaptive variable length coding (CAVLC), context adaptive binary arithmetic coding (CABAC), etc. For example, entropy encoding module 150 may perform entropy encoding using a codebook/variable length code (VLC). In addition, the entropy encoding module 150 can output the binarization method of the target symbol and the probability model of the target symbol/bin, and perform arithmetic encoding using the derived binarization method and context model.

[00128] To encode the transform coefficient level (quantized level), the entropy encoding module 150 can transform the coefficient in the form of a two-dimensional block into the form of a one-dimensional vector using a transform coefficient scanning method.

[00129] The encoding parameter may include information (flag, index, etc.) such as a syntax element that is encoded in the encoder and signaled to the decoder, and information output when encoding or decoding is performed. An encoding parameter may refer to information required when encoding or decoding an image. For example, at least one value or form of a combination of unit/block size, unit/block depth, unit/block partitioning information, unit/block shape, unit/block partition structure, whether to partition in the form of a quadtree, whether to partition in the form binary tree, the direction of partitioning of the binary tree form (horizontal direction or vertical direction), the partitioning shape of the binary tree form (symmetric partitioning or asymmetric partitioning), whether the current coding unit is partitioned by partitioning the ternary tree, the direction (horizontal or vertical direction) of partitioning the ternary tree , the type (symmetric or asymmetric type) of the ternary tree partition, whether the current encoding unit is partitioned by a multi-type tree partition, the direction (horizontal or vertical direction) of the multi-type tree partition, the type (symmetric or asymmetric type) of the multi-type tree partition, and the structure of the tree ( binary tree or ternary tree) tree partitions of multiple types, prediction mode (intra-prediction or inter-prediction), luma intra-prediction mode/direction, chrominance intra-prediction mode/direction, intra-partition information, inter-partition information, flag encoding block split flag, prediction block split flag, transform block split flag, reference sample filtering method, reference sample filter tap, reference sample filter coefficient, prediction block filtering method, prediction block filter tap, prediction block filter coefficient, prediction block boundary filtering method, prediction block boundary filter tap, prediction block boundary filter coefficient, intra-prediction mode, inter-prediction mode, motion information, motion vector, motion vector difference, reference picture index, inter-prediction angle, inter-prediction pointer, prediction list use flag , reference picture list, reference picture, motion vector predictor index, motion vector predictor candidate, motion vector candidate list, whether to use merge mode, merge index, merge candidate, merge candidate list, whether to use skip mode, interpolation filter type, tap interpolation filter, interpolation filter coefficient, motion vector size, motion vector representation precision, transformation type, transformation size, information whether the primary (first) transformation is used, information whether the secondary transformation is used, primary transformation index, secondary transformation index, information, represented whether the residual signal, coded block pattern, coded block flag (CBF), quantization parameter, quantization parameter remainder, quantization matrix, whether to apply an in-loop filter, in-loop filter coefficient, in-loop filter tap, in-loop filter shape, whether to apply a deblocking filter, deblocking filter coefficient, deblocking filter tap, deblocking filter strength, deblocking filter shape, whether to apply adaptive sample offset, adaptive sample offset value, adaptive sample offset category, adaptive sample offset type, whether to apply adaptive loop filter, coefficient adaptive loop filter, adaptive loop filter tap, adaptive loop filter shape, binarization/inverse binarization method, context model determination method, context model update method, whether to perform regular mode, whether to perform bypass mode, context bin, bypass bin, significant flag coefficient, the last significant coefficient flag, the coded flag for the unit of the coefficient group, the position of the last significant coefficient, the flag for whether the coefficient value is greater than 1, the flag for whether the coefficient value is greater than 2, the flag for whether whether the coefficient value is greater than 3, residual coefficient value information, sign information, reconstructed luminance sample, reconstructed chroma sample, residual luminance sample, residual chrominance sample, luminance conversion coefficient, chrominance conversion coefficient, quantized luminance level, quantized chrominance level, method conversion coefficient level scanning, decoder side motion vector search area size, decoder side motion vector search area shape, decoder side motion vector search number of times, CTU size information, minimum block size information, maximum block size information, information maximum block depth information, minimum block depth information, image display/output sequence, slice identification information, slice type, slice partition information, tile identification information, tile type, tile partition information, tile group identification information, tile group type elements, tile group partition information, picture type, input sample bit depth, reconstructed sample bit depth, residual sample bit depth, conversion coefficient bit depth, quantized level bit depth and luma signal information or chrominance signal information may be included in the parameter coding.

[00130] Here, signaling a flag or index may mean that the corresponding flag or index is entropy encoded and included in the bit stream by the encoder, and may mean that the corresponding flag or index is entropy decoded from the bit stream by the decoder.

[00131] When the encoding device 100 performs inter-prediction encoding, the encoded current image can be used as a reference image for another image that is processed thereafter. Accordingly, the encoding apparatus 100 may reconstruct or decode the encoded current picture, or store the reconstructed or decoded image as a reference picture in the reference picture buffer 190.

[00132] The quantized level may be dequantized in dequantization module 160 or may be inversely converted in dequantization module 170 . The dequantized and/or inversely transformed coefficient may be added to the prediction block via adder 175. By adding the dequantized and/or inversely transformed coefficient to the prediction block, a reconstructed block may be generated. Here, a dequantized and/or de-converted coefficient may mean a coefficient on which at least one of dequantization and de-conversion has been performed, and may denote a reconstructed residual block.

[00133] The recovered block may pass through filter module 180. Filtering module 180 may apply at least one of a deblocking filter, an adaptive sample offset (SAO), and an adaptive loop filter (ALF) to the reconstructed sample, the reconstructed block, or the reconstructed image. Filtration module 180 may be referred to as a loop filter.

[00134] A deblocking filter may remove block artifact generated at boundaries between blocks. To determine whether the deblocking filter should be applied, it may be determined whether the deblocking filter should be applied to the current block based on the samples included in the various rows or columns that are included in the block. When a deblocking filter is applied to a block, another filter may be applied according to the required strength (level) of deblocking filtering.

[00135] In order to compensate for encoding error, an appropriate offset value can be added to the sample value using an adaptive sample offset. Adaptive sampling offset can adjust the offset of the deblocked image relative to the original image by a sampling unit. A method may be used of dividing the image samples into a predetermined number of regions, determining the region to which the offset is applied and applying the offset to the defined region, or a method of applying the offset taking into account edge information on each sample.

[00136] The adaptive edge filter can perform filtering based on a comparison result between the filtered reconstructed image and the original image. The samples included in the image can be divided into predefined groups, a filter can be defined to apply to each group, and differential filtering can be performed on each group. Information about whether ALF should be applied may be signaled by coding units (CUs), and the shape and ratio of the ALF to be applied to each block may vary.

[00137] The reconstructed block or reconstructed image, after passing through the filtering module 180, may be stored in the reference picture buffer 190. The reconstructed block processed by filtering module 180 may be part of a reference image. That is, the reference image is a reconstructed image composed of reconstructed blocks processed by the filtering unit 180. The stored reference image can be used later in inter-prediction or motion compensation.

[00138] FIG. 2 is a block diagram showing the configuration of a decoding apparatus according to an embodiment to which the present invention is applicable.

[00139] The decoding device 200 may be a decoder, a video decoding device, or an image decoding device.

[00140] With reference to FIG. 2, the decoding apparatus 200 may include an entropy decoding unit 210, a dequantization unit 220, an inverse transform unit 230, an intra-prediction unit 240, a motion compensation unit 250, an adder 225, a filtering unit 260, and a reference picture buffer 270.

[00141] The decoding device 200 may receive a bit stream output from the encoding device 100. The decoding apparatus 200 may receive a bit stream stored in a computer-readable recording medium, or may receive a bit stream transmitted by streaming via a wired/wireless transmission medium. The decoding apparatus 200 may decode the bit stream using intra mode or inter mode. In addition, the decoding apparatus 200 can generate a reconstructed image generated by decoding or a decoded image and output the reconstructed image or decoded image.

[00142] When the prediction mode used in decoding is intra mode, the switch may be switched to intra mode. Alternatively, when the prediction mode used in decoding is inter-mode, the switch may be switched to inter-mode.

[00143] The decoding apparatus 200 can obtain the reconstructed residual block by decoding the input bit stream and generate a prediction block. When the reconstructed residual block and the prediction block are received, the decoding apparatus 200 can generate a reconstructed block that becomes a decoding target by summing the reconstructed residual block with the prediction block. The decoding target block may be called the current block.

[00144] The entropy decoding unit 210 may generate symbols by entropy decoding a bitstream according to a probability distribution. The generated symbols may include a quantized level shape symbol. Here, the entropy decoding method may be a reverse process to the entropy encoding method described above.

[00145] In order to decode the transform coefficient level (quantized level), the entropy decoding unit 210 can transform the coefficient in the form of a one-dimensional vector into a two-dimensional block form using a transform coefficient scanning method.

[00146] The quantized level may be dequantized in dequantization module 220 or inverted in dequantization module 230. The quantized level may be the result of dequantization and/or deconversion and may be generated as a reconstructed residual block. Here, dequantization module 220 may apply a quantization matrix to the quantized level.

[00147] When the intra mode is used, the intra prediction module 240 can generate a prediction block by performing, for the current block, a spatial prediction that uses the sample value of a block adjacent to the decoding target block and that has already been decoded.

[00148] When inter-mode is used, motion compensation module 250 can generate a prediction block by performing, for the current block, motion compensation that uses a motion vector and a reference picture stored in the reference picture buffer 270.

[00149] Adder 225 may generate a reconstructed block by adding the reconstructed residual block to the prediction block. Filtering module 260 may apply at least one of a deblocking filter, an adaptive sample offset, and an adaptive contour filter to the reconstructed block or reconstructed image. The filtering module 260 may output the reconstructed image. The reconstructed block or reconstructed image may be stored in reference picture buffer 270 and used when performing inter-prediction. The reconstructed block processed by filtering module 260 may be part of a reference image. That is, the reference image is a reconstructed image composed of reconstructed blocks processed by the filtering module 260. The saved reference image can be used later for inter-prediction or motion compensation.

[00150] FIG. 3 is a view schematically showing an image division structure in image encoding and decoding. Fig. 3 schematically shows an example of breaking one unit into many lower units.

[00151] In order to efficiently partition an image during encoding and decoding, a coding unit (CU) may be used. The coding unit can be used as a basic unit when encoding/decoding an image. In addition, the encoding unit can be used as a unit for distinguishing between an intra-prediction mode and an inter-prediction mode when encoding/decoding an image. The coding unit may be a basic unit used for prediction, transform, quantization, inverse transform, dequantization, or a transform coefficient encoding/decoding process.

[00152] With reference to FIG. 3, the image 300 is sequentially divided into a largest coding unit (LCU), and the LCU is defined as a division structure. Here, LCU can be used in the same sense as a coding tree unit (CTU). Splitting a unit may mean splitting the block associated with the unit. Unit depth information may be included in the block splitting information. The depth information may represent the number of times and/or the degree to which a unit is split. One unit may be broken down into multiple lower level units hierarchically associated with depth information based on a tree structure. In other words, a certain unit and a lower level unit generated by splitting a given unit can correspond to a node and a child node of a given node, respectively. Each divided lower unit may have depth information. The depth information may be information representing the size of a CU and may be stored in each CU. The depth of a unit represents the number of times and/or degrees of division of a unit. Therefore, the partitioning information of a lower-level unit may contain information about the size of the lower-level unit.

[00153] A partitioning structure may refer to the allocation of a coding unit (CU) within the LCU 310. Such allocation may be determined according to whether one CU should be partitioned into a plurality (a positive integer equal to or greater than 2, including 2, 4 , 8, 16, etc.) CU. The horizontal size and vertical size of the CU generated by partitioning may respectively be half the horizontal size and vertical size of the CU before partitioning, or may suitably have dimensions smaller than the horizontal size and vertical size before partitioning, according to the number of times of partitioning. A CU can be recursively split into multiple CUs. By recursively partitioning, at least one of the height and width of the CU after the partition can be reduced compared to at least one of the height and width of the CU before the partition. CU partitioning can be performed recursively to a predefined depth or predefined size. For example, the LCU depth may be 0, and the smallest coding unit (SCU) depth may be a predefined maximum depth. Here, the LCU may be a coding unit having a maximum coding unit size, and the SCU may be a coding unit having a minimum coding unit size, as described above. Partitioning starts from LCU 310, the CU depth increases by 1 as the horizontal size and/or vertical size of the CU is reduced by partitioning. For example, for each depth, a CU that is not partitioned may have a size of 2N×2N. Also, in the case of a CU that is partitioned, a 2N×2N size CU may be split into four N×N size CUs. The size N can be reduced by half when the depth increases by 1.

[00154] In addition, information about whether the CU should be split may be provided using the CU split information. The partition information may be 1-bit information. All CUs except SCU may include partitioning information. For example, when the value of the partition information is equal to the first value, the CU may not be partitioned; when the value of the partition information is equal to the second value, the CU may be partitioned.

[00155] With reference to FIG. 3, an LCU having a depth of 0 may be a 64x64 block. 0 may be the minimum depth. An SCU having a depth of 3 may be an 8x8 block. 3 may be the maximum depth. CUs in the form of 32x32 blocks and 16x16 blocks can be represented as depth 1 and depth 2, respectively.

[00156] For example, when one encoding unit is divided into four encoding units, the horizontal size and vertical size of the four divided encoding units may be equal to half the size of the horizontal and vertical size of the CU before dividing. In one embodiment, when a coding unit having a size of 32×32 is divided into four coding units, each of the four divided coding units may have a size of 16×16. When one coding unit is split into four coding units, it can be said that the coding unit can be split into a quadtree shape.

[00157] For example, when one encoding unit is split into two sub-encoding units, the horizontal or vertical size (width or height) of each of the two sub-encoding units may be half the horizontal or vertical size of the original encoding unit. For example, when a coding unit having a size of 32×32 is vertically divided into two sub-coding units, each of the two sub-coding units may have a size of 16×32. For example, when a coding unit having a size of 8x32 is horizontally divided into two sub-coding units, each of the two sub-coding units may have a size of 8x16. When one coding unit is split into two sub-coding units, the coding unit can be said to be binary split or split through a binary tree split structure.

[00158] For example, when one encoding unit is divided into three sub-encoding units, the horizontal or vertical size of the encoding unit may be divided in the ratio 1:2:1, thereby forming three sub-encoding units whose horizontal or vertical dimensions are in the ratio 1:2:1. For example, when a coding unit having a size of 16×32 is horizontally divided into three sub-coding units, the three sub-coding units may have dimensions of 16×8, 16×16 and 16×8, respectively, in order from the highest to the highest lower sub-unit coding. For example, when a coding unit having a size of 32×32 is vertically divided into three sub-coding units, the three sub-coding units may have sizes of 8×32, 16×32 and 8×32, respectively, in order from left to right sub-units. coding units. When one coding unit is split into three sub-coding units, the coding unit can be said to be ternary split or split through a ternary tree split structure.

[00159] In FIG. 3, a coding tree unit (CTU) 320 is an example of a CTU to which a quadtree partitioning structure, a binary tree partitioning structure, and a ternary tree partitioning structure are applied.

[00160] As described above, in order to split the CTU, at least one of a quadtree splitting structure, a binary tree splitting structure, and a ternary tree splitting structure can be applied. Different tree partitioning structures can be applied sequentially to CTUs, according to a predefined order of priority. For example, a quadtree partitioning structure may advantageously apply to a CTU. A coding unit that can no longer be split using the quadtree splitting structure may correspond to a quadtree leaf node. The encoding unit corresponding to a leaf node of the quadtree may serve as the root node of the binary and/or ternary tree partition structure. That is, the encoding unit corresponding to a quadtree leaf node may be further partitioned according to a binary tree partitioning structure or a ternary tree partitioning structure, or may not be partitioned any more. Therefore, by prohibiting a coding block that results from binary tree splitting or ternary tree splitting of a coding unit corresponding to a quadtree leaf node from undergoing further quadtree splitting, block splitting and/or signaling of splitting information can be effectively performed.

[00161] The fact that a coding unit corresponding to a quadtree node is partitioned may be signaled using quad partition information. The quad-split information having a first value (eg, “1”) may indicate that the current encoding unit is split according to a quad-tree split structure. Quad-split information having a second value (eg, “0”) may indicate that the current encoding unit is not split according to a quad-tree split structure. The quad partition information may be a flag having a predetermined length (eg, one bit).

[00162] There may be no priority between binary tree splitting and ternary tree splitting. That is, the encoding unit corresponding to a leaf node of the quadtree may further be subject to arbitrary partitioning from a binary tree partition and a ternary tree partition. In addition, the encoding unit generated by binary tree splitting or ternary tree splitting may be subject to further binary tree splitting or further ternary tree splitting, or may not be further split.

[00163] A tree structure in which there is no priority among binary tree partitioning and ternary tree partitioning is referred to as a multi-type tree structure. The encoding unit corresponding to a leaf node of a quadtree can serve as the root node of a tree of multiple types. Whether or not to split an encoding unit that corresponds to a node of a multi-type tree may be signaled using at least one of multi-type tree splitting indication information, splitting direction information, and splitting tree information. To partition an encoding unit corresponding to a node of a multi-type tree, the multi-type tree partitioning indication information, the partitioning direction, and the partition tree information may be signaled sequentially.

[00164] The multi-type tree splitting indication information having a first value (eg, “1”) may indicate that the current encoding unit should undergo multi-type tree splitting. The multitype tree splitting indication information having a second value (eg, “0”) may indicate that the current encoding unit should not undergo multitype tree splitting.

[00165] When an encoding unit corresponding to a node of a multi-type tree is further partitioned according to a partitioning structure of the multi-type tree, the encoding unit may include partitioning direction information. The split direction information may indicate in which direction the current encoding unit should be split to split a tree of multiple types. The split direction information having a first value (eg, “1”) may indicate that the current coding unit should be split vertically. The split direction information having a second value (eg, “0”) may indicate that the current coding unit should be split horizontally.

[00166] When an encoding unit corresponding to a multi-type tree node is further partitioned according to a multi-type tree partitioning structure, the current encoding unit may include partition tree information. The partition tree information may indicate a partition tree structure that should be used to partition a tree node of the plurality of types. The split tree information having a first value (eg, “1”) may indicate that the current encoding unit should be split according to the binary tree split structure. The split tree information having a second value (eg, “0”) may indicate that the current coding unit should be split according to a ternary tree split structure.

[00167] The partition indication information, the partition tree information, and the partition direction information may each be a flag having a predetermined length (eg, one bit).

[00168] At least any one of the quad-tree partition indication information, the multi-type tree partition indication information, the partition direction information, and the partition tree information can be entropy encoded/decoded. For entropy encoding/decoding of these types of information, information about a neighboring coding unit adjacent to the current coding unit can be used. For example, there is a high probability that the split type (split or unsplit, split tree and/or split direction) of the left adjacent coding unit and/or top neighboring coding unit of the current coding unit is similar to that of the current coding unit. Therefore, context information for entropy encoding/decoding information about the current encoding unit can be inferred from information about neighboring encoding units. The neighbor encoding unit information may include at least any one of quad-partitioning information, multiple-type tree partitioning indication information, partitioning direction information, and partitioning tree information.

[00169] As another example, from binary tree splitting and ternary tree splitting, binary tree splitting may preferably be performed. That is, the current encoding unit may be mainly subjected to binary tree splitting, and then the encoding unit corresponding to a leaf node of the binary tree may be set as a root node for ternary tree splitting. In this case, neither the quadtree split nor the binary tree split may be performed on the coding unit corresponding to the ternary tree node.

[00170] An encoding unit that cannot be partitioned according to a quadtree partition structure, a binary tree partition structure, and/or a ternary tree partition structure becomes a basic unit for encoding, prediction, and/or transformation. That is, the coding unit cannot be further broken down for prediction and/or transformation. Therefore, partition structure information and partition information used to partition a coding unit into prediction units and/or transformation units may not be represented in the bit stream.

[00171] However, when the size of the coding unit (i.e., the base unit for partitioning) is larger than the size of the maximum transform block, the coding unit may be recursively divided until the size of the coding unit is reduced to be equal to or less than than the size of the maximum conversion block. For example, when the coding unit size is 64×64 and when the maximum transform block size is 32×32, the coding unit may be divided into four 32×32 transform blocks. For example, when the coding unit size is 32×64 and the maximum transform block size is 32×32, the coding unit may be divided into two 32×32 transform blocks. In this case, the partition of the coding unit for transformation is not signaled separately and can be determined by comparison between the horizontal or vertical size of the coding unit and the horizontal or vertical size of the maximum transformation block. For example, when the horizontal size (width) of a coding unit is larger than the horizontal size (width) of a maximum transform block, the coding unit may be vertically divided into halves. For example, when the vertical size (length) of a coding unit is larger than the vertical size (length) of a maximum transform block, the coding unit may be horizontally divided into halves.

[00172] The maximum and/or minimum coding unit size information and the maximum and/or minimum transform block size information may be signaled or determined at a higher coding unit level. The higher level may be, for example, a sequence level, a picture level, a slice level, a tile group level, a tile level, or the like. For example, the minimum coding unit size may be defined as 4x4. For example, the maximum transform block size may be defined as 64×64. For example, the minimum transform block size may be defined as 4x4.

[00173] Information about the minimum size (minimum quadtree size) of a coding unit corresponding to a leaf node of the quadtree, and/or information about the maximum depth (maximum tree depth for a tree of multiple types) from a root node to a leaf node of a tree of multiple types may be signaled or determined at higher level coding unit. For example, the higher level may be a sequence level, a picture level, a slice level, a tile group level, a tile level, or the like. Minimum quadtree size information and/or maximum tree depth information of multiple types may be signaled or determined for each of the intra-picture slice and inter-picture slice.

[00174] The difference information between the CTU size and the maximum transform unit size may be signaled or determined at a higher coding unit level. For example, the higher level may be a sequence level, a picture level, a slice level, a tile group level, a tile level, or the like. Information about the maximum size of encoding units corresponding to the corresponding nodes of the binary tree (hereinafter referred to as the maximum size of the binary tree) may be determined based on the unit size of the encoding tree and the delta information. The maximum size of coding units corresponding to the corresponding nodes of the ternary tree (hereinafter referred to as the maximum size of the ternary tree) may vary depending on the type of slice. For example, for an intra-picture slice, the maximum size of the ternary tree can be 32x32. For example, for an inter-picture slice, the maximum size of the ternary tree can be 128x128. For example, the minimum size of encoding units corresponding to the corresponding nodes of a binary tree (hereinafter referred to as the minimum size of a binary tree) and/or the minimum size of encoding units corresponding to the corresponding nodes of a ternary tree (hereinafter referred to as the minimum size of a ternary tree) may be set as minimum coding block size.

[00175] As another example, the maximum binary tree size and/or the maximum ternary tree size may be signaled or determined at the slice level. Alternatively, the minimum binary tree size and/or the minimum ternary tree size may be signaled or determined at the slice level.

[00176] Depending on the size and depth information of the various blocks described above, quad-partition information, multiple-type tree partition indication information, partition tree information, and/or partition direction information may or may not be included in the bit stream.

[00177] For example, when the size of a coding unit is not larger than the minimum quadtree size, the coding unit does not contain quad-partition information. Thus, the quad-partition information can be inferred from the second value.

[00178] For example, when the dimensions (horizontal and vertical dimensions) of a coding unit corresponding to a tree node of a plurality of types are larger than the maximum dimensions (horizontal and vertical dimensions) of a binary tree and/or the maximum dimensions (horizontal and vertical dimensions) of a ternary tree, the unit encoding may not be binary separated or ternary separated. Accordingly, tree splitting indication information of a plurality of types may not be signaled, but may be derived from the second value.

[00179] Alternatively, when the dimensions (horizontal and vertical dimensions) of the encoding unit corresponding to a tree node of the plurality of types are the same as the maximum dimensions (horizontal and vertical dimensions) of the binary tree and/or twice larger than the maximum dimensions (horizontal and vertical dimensions) of a ternary tree, the coding unit cannot be further binary-divided or ternary-divided. Accordingly, tree splitting indication information of a plurality of types may not be signaled, but may be derived from the second value. This is because when a coding unit is split according to a binary tree splitting structure and/or a ternary tree splitting structure, a coding unit smaller than the minimum binary tree size and/or the minimum ternary tree size is generated.

[00180] Alternatively, the binary tree split or ternary tree split may be limited based on the size of the virtual pipeline data unit (hereinafter, pipeline buffer size). For example, when an encoding unit is divided into sub-encoding units that do not correspond to a pipeline buffer size by a binary tree split or a ternary tree split, the corresponding binary tree split or ternary tree split may be constrained. The pipeline buffer size can be the size of the maximum translation block (eg, 64x64). For example, when the pipeline buffer size is 64x64, the division below may be limited.

[00181] - N×M (N and/or M is 128) Ternary tree partition for coding units

[00182] - 128×N (N<=64) Horizontal binary tree split for coding units

[00183] - N×128 (N<=64) Vertical binary tree partition for coding units

[00184] Alternatively, when the depth of a coding unit corresponding to a multi-type tree node is equal to the maximum depth of the multi-type tree, the coding unit cannot be further binary and/or ternary split. Accordingly, tree splitting indication information of a plurality of types may not be signaled, but may be derived from the second value.

[00185] Alternatively, only when at least one of vertical binary tree splitting, horizontal binary tree splitting, vertical ternary tree splitting, and horizontal ternary tree splitting is possible for a coding unit corresponding to a tree node of a plurality of types, tree splitting indicating information of a plurality of types may be signaled. Otherwise, the coding unit cannot be binary and/or ternary split. Accordingly, tree splitting indication information of a plurality of types may not be signaled, but may be derived from the second value.

[00186] Alternatively, only when, for a coding unit corresponding to a tree node of multiple types, both a binary tree split in the vertical direction and a binary tree split in the horizontal direction, or both a ternary tree split in the vertical direction and a ternary tree split in the horizontal direction, are possible horizontal direction, splitting direction information may be signaled. Otherwise, the split direction information may not be signaled, but may be inferred from a value indicating possible split directions.

[00187] Alternatively, only when, for a coding tree corresponding to a tree node of multiple types, both a binary tree split in the vertical direction and a ternary tree split in the vertical direction are possible, or both a binary tree split in the horizontal direction and a ternary tree split in the horizontal direction, partition tree information may be signaled. Otherwise, the split tree information may not be signaled, but may be inferred from a value indicating a possible split of the tree structure.

[00188] FIG. 4 is a view showing the intra-prediction process.

[00189] The arrows are from the center outward in FIG. 4 may represent prediction directions of intra-prediction modes.

[00190] Intra encoding and/or decoding may be performed using a reference sample of an adjacent block of the current block. The neighbor block may be a reconstructed neighbor block. For example, intra-encoding and/or decoding may be performed using an encoding parameter or a reference sample value included in the reconstructed neighboring block.

[00191] A prediction block may mean a block generated by performing intra-prediction. The prediction unit may correspond to at least one of a CU, a PU, and a TU. The prediction block unit may have the size of one of CU, PU and TU. The prediction block may be a square block having a size of 2x2, 4x4, 16x16, 32x32 or 64x64, etc., or may be a rectangular block having a size of 2x8, 4x8, 2x16, 4x16 and 8x16, etc.

[00192] Intra prediction may be performed according to the intra prediction mode for the current block. The number of intra-prediction modes that the current block can have may be a fixed value and may be a value defined differently according to an attribute of the prediction block. For example, the prediction block attribute may include the size of the prediction block and the shape of the prediction block, etc.

[00193] The number of intra-prediction modes can be fixed to N regardless of the block size. Or the number of intra-prediction modes can be 3, 5, 9, 17, 34, 35, 36, 65 or 67, etc. Alternatively, the number of intra-prediction modes may vary according to the block size or color component type or both. For example, the number of intra-prediction modes may vary according to whether the color component is a luma signal or a chrominance signal. For example, when the block size becomes large, the number of intra-prediction modes may increase. Alternatively, the number of intra-prediction modes of the luma component block may be greater than the number of intra-prediction modes of the chrominance component block.

[00194] The intra-prediction mode may be a non-angular mode or an angular mode. The non-angular mode may be a DC mode or a planar mode, and the angular mode may be a prediction mode having a specific direction or angle. The intra-prediction mode may be expressed by at least one of a mode number, a mode value, a mode number symbol, a mode angle, and a mode direction. The number of intra-prediction modes can be M, which is greater than 1, including non-angular and angular mode. For intra-prediction of the current block, the step of determining whether samples included in the reconstructed neighboring block can be used as reference samples of the current block can be performed. When there is a sample that cannot be used as the reference sample of the current block, the value obtained by duplicating or interpolating at least one sample value among the samples included in the reconstructed adjacent block, or both, can be used to replace the unused sample value for the sample. thus, the replaced sample value is used as the reference sample of the current block.

[00195] FIG. 7 is a diagram illustrating reference samples that can be used for intra-prediction.

[00196] As shown in FIG. 7, at least one of reference sample line 0 and reference sample line 3 may be used for intra-prediction of the current block. In fig. 7, the samples of segment A and segment F can be padded with samples closest to segment B and segment E, respectively, instead of extracting from the reconstructed neighboring block. Index information indicating the reference sample line that should be used for intra-prediction of the current block may be signaled. When the upper boundary of the current block is the CTU boundary, only line 0 of the reference sample can be accessed. Therefore, in this case, the index information may not be signaled. When a reference sample line other than reference sample line 0 is used, filtering for the prediction block to be described later may not be performed.

[00197] In intra-prediction, a filter may be applied to at least one of a reference sample and a prediction sample based on the intra-prediction mode and the current block size.

[00198] In the case of planar mode, when generating a prediction block of the current block, according to the position of the prediction target sample in the prediction block, the sample value of the prediction target sample can be generated using the weighted sum of the top and left side reference samples for the current sample, and the reference samples the top right side and bottom left side of the current block. In addition, in the case of DC mode, when generating a prediction block of the current block, the average value of the reference samples of the top and left side of the current block may be used. Moreover, in the case of corner mode, a prediction block may be generated using a reference sample of the top side, left side, right top side, and/or left bottom side of the current block. To generate a prediction sample value, unit interpolation of the real number may be performed.

[00199] In the case of intra-prediction between color components, a prediction block for the current block of the second color component can be generated based on the corresponding reconstructed block of the first color component. For example, the first color component may be a luma component, and the second color component may be a chrominance component. For intra-prediction between color components, parameters of a linear model between the first color component and the second color component can be obtained based on the template. The template may include top and/or left neighbor samples of the current block and top and/or left neighbor samples of the reconstructed block of the first color component corresponding thereto. For example, the linear model parameters may be derived using the sample value of the first color component having the maximum value among the samples in the template, and the sample value of the second color component corresponding to it, and the sample value of the first color component having the minimum value among the samples in the template, and the sample value of the second color component corresponding to it. Once the parameters of the linear model are inferred, the corresponding reconstructed block can be applied to the linear model to generate a prediction block for the current block. According to the video format, subsampling may be performed on adjacent samples of the reconstructed block of the first color component and the corresponding reconstructed block. For example, when one sample of the second color component corresponds to four samples of the first color component, the four samples of the first color component may be subsampled to compute one corresponding sample. In this case, linear model parameter inference and intra-prediction between color components can be performed based on the corresponding downsampled samples. Whether or not to perform intra-prediction between color components and/or pattern range may be signaled as an intra-prediction mode.

[00200] The current block can be divided into two or four sub-blocks in the horizontal or vertical direction. Broken subblocks can be sequentially restored. That is, intra-prediction may be performed on the sub-block to generate a prediction sub-block. Additionally, dequantization and/or deconversion may be performed on the subblocks to generate residual subblocks. The reconstructed subblock can be generated by adding a prediction subblock to the residual subblock. The reconstructed sub-block can be used as a reference sample for intra-prediction of sub-sub-blocks. A subblock may be a block containing a predetermined number (eg, 16) or more samples. Accordingly, for example, when the current block is an 8×4 or 4×8 block, the current block may be divided into two sub-blocks. In addition, when the current block is a 4x4 block, the current block cannot be divided into subblocks. When the current block has different sizes, the current block can be split into four subblocks. Information about whether to perform intra-prediction based on sub-blocks and/or the direction of partitioning (horizontal or vertical) may be signaled. Intra-prediction based on sub-blocks can be limited to execution only when reference sample line 0 is used. When intra-prediction based on a sub-block is performed, filtering for the prediction block, which will be described later, may not be performed.

[00201] The final prediction block can be generated by performing filtering on a prediction block that is intra-predicted. Filtering can be performed by applying predefined weights to the filter target sample, the left reference sample, the top reference sample, and/or the top left reference sample. The weight and/or reference sample (range, position, etc.) used for filtering may be determined based on at least one of block size, intra-prediction mode, and position of the target filter sample in the prediction block. Filtering can only be performed in the case of a predefined intra-prediction mode (eg, DC, planar, vertical, horizontal, diagonal and/or adjacent diagonal modes). An adjacent diagonal mode may be a mode in which k is added to or subtracted from the diagonal mode. For example, k can be a positive integer 8 or less.

[00202] The intra-prediction mode of the current block can be entropy encoded/decoded by predicting the intra-prediction mode of a block adjacent to the current block. When the intra-prediction modes of the current block and the neighboring block are identical, information that the intra-prediction modes of the current block and the neighboring block are identical may be signaled using predefined flag information. In addition, intra-prediction mode indicator information that is identical to the intra-prediction mode of the current block among the intra-prediction modes of a plurality of neighboring blocks may be signaled. When the intra-prediction modes of the current block and the neighboring block are different, the intra-prediction mode information of the current block can be entropy encoded/decoded by performing entropy encoding/decoding based on the intra-prediction mode of the neighboring block.

[00203] FIG. 5 is a diagram illustrating an embodiment of the inter-prediction process.

[00204] In FIG. 5 a rectangle can represent a picture. In fig. 5, the arrow represents the direction of the prediction. Pictures can be classified into intrinsic pictures (I-pictures), predictive pictures (P-pictures) and bi-predictive pictures (B-pictures) according to their encoding type.

[00205] The I-picture can be encoded by intra-prediction without the need for inter-picture (inter-frame) prediction. The P-picture may be encoded by inter-picture prediction using a reference picture that is present in one direction (ie, forward direction or backward direction) relative to the current block. The B-picture may be encoded by inter-picture prediction using reference pictures that are preset in two directions (ie, forward direction and backward direction) relative to the current block. When inter-picture prediction is used, the encoder may perform inter-prediction or motion compensation, and the decoder may perform corresponding motion compensation.

[00206] An embodiment of inter-picture prediction will be described in detail below.

[00207] Inter-prediction or motion compensation may be performed using the reference picture and motion information.

[00208] Motion information of the current block may be output during inter-prediction by each of the encoding device 100 and the decoding device 200. The motion information of the current block can be output by using the motion information of a reconstructed adjacent block, the motion information of a combined block (also called a col block or a collocated block), and/or a block adjacent to a collocated block. A aligned block may mean a block that is spatially located at the same position as the current block in a previously reconstructed fused picture (also referred to as a col picture or fused picture). The combined picture may be one picture from one or more reference pictures included in the reference picture list.

[00209] The method for outputting motion information may differ depending on the prediction mode of the current block. For example, the prediction mode used for inter-prediction includes AMVP mode, fusion mode, skip mode, motion vector difference fusion mode, sub-block fusion mode, triangular partition mode, inter-intra combined prediction mode, affine mode, etc. P. Here, the fusion mode may be referred to as the motion fusion mode.

[00210] For example, when AMVP is used as a prediction mode, at least one of motion vectors of reconstructed adjacent blocks, motion vectors of aligned blocks, motion vectors of blocks adjacent to aligned blocks, and a (0, 0) motion vector may be determined in as motion vector candidates for the current block, and a list of motion vector candidates is generated using the motion vector candidates. The motion vector candidate of the current block can be inferred using the generated list of motion vector candidates. The motion information of the current block can be determined based on the derived motion vector candidate. Motion vectors of aligned blocks or motion vectors of blocks adjacent to aligned blocks may be referred to as temporal motion vector candidates, and motion vectors of reconstructed adjacent blocks may be referred to as spatial motion vector candidates.

[00211] The encoding apparatus 100 may calculate a motion vector difference (MVD) between a motion vector of the current block and a motion vector candidate, and may perform entropy encoding of the motion vector difference (MVD). In addition, the encoding device 100 can perform entropy encoding of the motion vector candidate index and generate a bit stream. The motion vector candidate index may indicate an optimal motion vector candidate among the motion vector candidates included in the motion vector candidate list. The decoding apparatus may perform entropy decoding on a motion vector candidate index included in the bitstream, and may select a motion vector candidate of the decoding target block from among the motion vector candidates included in the motion vector candidate list using the entropy decoded motion vector candidate index. In addition, the decoding apparatus 200 may add the entropy decoded MVD and the motion vector candidate extracted by entropy decoding, thereby outputting the motion vector of the decoding target block.

[00212] Meanwhile, the encoding device 100 can perform entropy encoding on the resolution information of the calculated MVD. The decoding apparatus 200 may adjust the resolution of the entropy-decoded MVD using the MVD resolution information.

[00213] Meanwhile, the encoding device 100 calculates the motion vector difference (MVD) between the motion vector and the motion vector candidate in the current block based on the affine model and performs entropy encoding on the MVD. The decoding apparatus 200 outputs a motion vector for each sub-block by deriving the affine control motion vector of the decoding target block through the sum of the entropy decoded MVD and the affine control motion vector candidate.

[00214] The bitstream may include a reference picture index indicating the reference picture. The reference picture index may be entropy encoded by encoder 100 and then signaled as a bitstream to decoder 200. The decoding apparatus 200 may generate a prediction block from a target decoding block based on the derived motion vector and reference picture index information.

[00215] Another example of a method for outputting current motion information may be a merge mode. Merge mode may refer to a method of merging the movement of multiple blocks. The merging mode may mean a mode of deriving motion information of the current block from motion information of neighboring blocks. When the merging mode is applied, a merging candidate list may be generated using motion information of reconstructed neighboring blocks and/or motion information of merged blocks. The motion information may include at least one of a motion vector, a reference picture index, and an inter-prediction indicator. The prediction indicator may indicate unidirectional prediction (L0 prediction or L1 prediction) or bidirectional prediction (L0 prediction and L1 prediction).

[00216] The merge candidate list may be a list of stored motion information. The motion information included in the fusion candidate list may be at least one of the motion information (spatial fusion candidate) of a neighboring block adjacent to the current block, the motion information (temporal fusion candidate) of the merged block of the current block in the reference picture, new motion information, generated by a combination of the motion information output from the merge candidate list, the motion information (history-based merge candidate) of the block that is encoded/decoded before the current block, and the null merge candidate.

[00217] The encoding apparatus 100 may generate a bitstream by performing entropy encoding on at least one of a merge flag and a merge index, and may signal the bitstream to the decoding apparatus 200. The merge flag may be information indicating whether to perform a merge mode for each block, and the merge index may be information indicating which neighboring block among neighboring blocks of the current block is a merge target block. For example, the neighbor blocks of the current block may include a left neighbor block on the left side of the current block, a top neighbor block located above the current block, and a temporal neighbor block temporally adjacent to the current block.

[00218] Meanwhile, the encoding device 100 performs entropy encoding on the correction information for correcting the motion vector among the motion information of the fusion candidate and signals it to the decoding device 200. The decoding apparatus 200 may correct the motion vector of the fusion candidate selected by the fusion index based on the correction information. Here, the correction information may include at least one of information about whether to perform correction or not, correction direction information, and correction size information. As described above, a prediction mode that corrects the motion vector of a fusion candidate based on the signaled correction information may be referred to as a fusion mode having a motion vector difference.

[00219] The skip mode may be a mode in which the motion information of a neighboring block is applied to the current block as is. When the skip mode is applied, the encoding device 100 can perform entropy encoding of information that the motion information of a particular block should be used as the motion information of the current block to generate a bit stream, and can signal the bit stream to the decoding device 200. The encoding device 100 may not signal a syntax element regarding at least any one of the motion vector difference information, the encoding block flag, and the level of transform coefficients to the decoding device 200.

[00220] A subblock merging mode may mean a mode that outputs motion information in units of coding unit (CU) subblocks. When the sub-block merging mode is applied, a sub-block merging candidate list can be generated using the motion information (sub-block-based temporary merging candidate) of the sub-block aligned with the current sub-block in the reference image and/or the affine control point motion vector merging candidate.

[00221] The triangular partitioning mode may mean a mode that outputs motion information by dividing the current block into diagonal directions, outputs each prediction sample using each output motion information, and extracts the prediction sample of the current block by weighting each of the output prediction samples.

[00222] A combined inter-intra prediction mode may mean a mode that outputs a prediction sample of the current block by weighting the prediction sample generated by inter-prediction and the prediction sample generated by intra-prediction.

[00223] The decoding device 200 can independently correct the output motion information. The decoding apparatus 200 can search a specified area based on the reference block indicated by the output motion information, and output motion information having a minimum SAD as corrected motion information.

[00224] The decoding apparatus 200 may compensate the prediction sample output by inter-prediction using optical flow.

[00225] FIG. 6 is a diagram illustrating the conversion and quantization process.

[00226] As shown in FIG. 6, a conversion and/or quantization process is performed on the residual signal to generate a quantized level signal. The residual signal represents the difference between the original block and the prediction block (ie, intra-prediction block or inter-prediction block). A prediction block is a block generated by intra-prediction or inter-prediction. The transformation can be a primary transformation, a secondary transformation, or both. Primary transformation of the residual signal results in transformation coefficients, and secondary transformation of the transformation coefficients results in secondary transformation coefficients.

[00227] At least one scheme selected from various conversion schemes that are predefined is used to perform the primary conversion. For example, examples of predefined transform schemes include discrete cosine transform (DCT), discrete sine transform (DST), and Karhunen-Loeve transform (KLT). Transformation coefficients generated by the primary transformation may be subject to a secondary transformation. The transform schemes used for the primary transform and/or secondary transform may be determined according to the encoding parameters of the current block and/or neighboring blocks of the current block. Alternatively, conversion information indicating the conversion scheme may be signaled. The DCT-based conversion may include, for example, DCT-2, DCT-8, and the like. The DST-based conversion may include, for example, DST-7.

[00228]

[00229] The quantized level signal (quantization coefficients) can be generated by performing quantization on the residual signal or the result of performing the primary transform and/or secondary transform. The quantized level signal may be scanned according to at least one of a diagonal up-right scan, a vertical scan, and a horizontal scan, depending on the block intra-prediction mode or the block size/shape. For example, when coefficients are scanned in a diagonal up-to-right scan, the coefficients in block form are converted to one-dimensional vector form. In addition to the up-right diagonal scan, horizontal scan horizontal scan of the 2D shape of the coefficient block or vertical scan of the vertical scan of the 2D shape of the coefficient block can be used depending on the intra-prediction mode and/or the size of the transform block. The scanned quantized layer coefficients can be entropy encoded for insertion into the bit stream.

[00230] The decoder performs entropy decoding of the bit stream to obtain quantized level coefficients. The quantized level coefficients can be arranged in a two-dimensional block form by backscanning. The reverse scan may use at least one of a diagonal up-right scan, a vertical scan, and a horizontal scan.

[00231] The quantized level coefficients can then be dequantized, then subjected to a secondary inverse transform if necessary, and finally a primary inverse transform if necessary to generate a reconstructed residual signal.

[00232] Dynamic range inverse mapping may be performed on the luminance component reconstructed by intra-prediction or inter-prediction before in-loop filtering. The dynamic range can be divided into 16 equal parts, and the display function for each part can be signaled. The mapping function can be signaled at the slice level or the tile group level. The inverse mapping function for performing the inverse mapping can be derived based on the mapping function. Contour filtering, reference picture storage and motion compensation are performed in the inverse mapping region, and the prediction block generated by inter-prediction is converted into the mapping region by mapping using a mapping function, and then used to generate the reconstructed block. However, since intra-prediction is performed on the mapped area, the prediction block generated by intra-prediction can be used to generate a reconstructed block without mapping/demapping.

[00233] When the current block is a residual block of a chroma component, the residual block can be converted into a reverse mapping region by performing scaling of the chrominance component of the mapped region. Scaling availability can be signaled at the slice level or the tile group level. Scaling can only be applied when mapping is available for the luma component, and the luma component division and the chrominance component division follow the same tree structure. The scaling may be performed based on the average of the samples of the luminance prediction block corresponding to the color difference block. In this case, when the current block uses inter-prediction, the luminance prediction block may mean the mapped luminance prediction block. The value required for scaling can be obtained by accessing the lookup table using the index of the slice to which the average value of the brightness prediction block samples belongs. Finally, by scaling the residual block using the output value, the residual block can be switched to the reverse mapping region. Then, chrominance component block recovery, intra-prediction, inter-prediction, contour filtering, and reference picture storage can be performed in the demapping region.

[00234] Information indicating whether luma component and chroma component mapping/demapping is available may be signaled through a set of sequence parameters.

[00235] A current block prediction block may be generated based on a block vector indicating an offset between the current block and a reference block in the current image. Thus, the prediction mode for generating a prediction block with reference to the current picture is called intra-block copy (IBC) mode. The IBC mode can be applied to M×N coding units (M<=64, N<=64). The IBC mode may include a skip mode, a merge mode, an AMVP mode, and the like. In the case of skip mode or merge mode, a list of merge candidates is generated and the merge index is signaled so that one merge candidate can be specified. The block vector of the specified merge candidate can be used as the block vector of the current block. The list of merge candidates may include at least one of a spatial candidate, a history-based candidate, a candidate based on the average of two candidates, and a null merge candidate. In the case of AMVP mode, a difference block vector may be signaled. In addition, the prediction block vector can be derived from the left neighbor block and the top neighbor block of the current block. The index for the adjacent block to be used may be signaled. A prediction block in IBC mode is included in the current CTU or left CTU and is limited to a block in the already reconstructed region. For example, the value of the block vector may be constrained such that the prediction block of the current block is located in a region of three 64x64 blocks preceding the 64x64 block to which the current block belongs, in encoding/decoding order. By limiting the block vector value in this way, memory consumption and device complexity in accordance with the IBC mode implementation can be reduced.

[00236]

[00237] Next, a method for generating a motion information list according to an embodiment of the present invention will be described.

[00238] Further, the motion information list may refer to a list in which motion information generated when encoding or decoding an image is stored.

[00239] According to an embodiment of the present invention, motion information generated in inter-prediction can be stored in a motion information list, and motion information can be generated using the motion information list in inter-prediction of the next target encoding/decoding block.

[00240] Here, the motion information may mean at least one of a motion vector, a reference picture index, an inter-prediction indicator as described above, as well as a prediction list use flag, reference picture list information, a reference picture, a motion vector candidate, an index motion vector candidate, merge candidate, merge index and the like.

[00241] The motion information list may store motion information generated in a predetermined area.

[00242] As an example, the motion information list may be initialized by removing motion information from the motion information list or generating a new motion information list when encoding/decoding is completed in a predetermined area so that the area changes.

[00243] That is, a list of motion information may be generated based on a predetermined area (or a predetermined section, a predetermined unit). Here, the predetermined area related to the motion information list may be a unit larger than the unit in which inter-prediction is performed.

[00244] As an example, a predefined area related to the motion information list may be any one of a block consisting of one or more CUs, a CTU, a block consisting of one or more CTUs (eg, a CTU row), a bar ( brick), mosaic element, slice, picture, frame and group of pictures (GOP).

[00245] The predefined area associated with the motion information list may be called an upper prediction unit (UPU) or initialization area.

[00246] Meanwhile, the motion information list may be called an adaptive motion vector appearance list (AMVOL) or a history-based motion vector predictor list (HMVP list) according to an embodiment.

[00247] Meanwhile, the motion information list can only be used when the encoder/decoder operates in the inter-prediction mode or IBC mode.

[00248] FIG. 8 and 9 are diagrams illustrating an encoder and a decoder using the motion information list.

[00249] With reference to FIG. 8 and 9, the encoder and decoder can improve prediction efficiency using motion information stored in the motion information list in the inter-prediction process or the IBC prediction process.

[00250]

[00251] Meanwhile, a motion information list may be initialized or generated when encoding/decoding of a new UPU starts. Therefore, when encoding/decoding of a new UPU starts, the motion information list may not have motion information because inter-prediction is not performed in the new UPU. Since the motion information list does not have motion information, the motion information list may not be used in inter-prediction. In addition, when the amount of motion information stored in the motion information list is small, it is difficult to expect efficient encoding since there is little information used for inter-prediction.

[00252] In the present invention, when performing inter-prediction (or IBC prediction) when there is little or no motion information stored in the motion information list, a method is proposed for further storing predicted motion information in the motion information list to generate a motion information list .

[00253] Through the above method, it is possible to improve encoding efficiency by more accurately performing inter-prediction using the motion information list.

[00254]

[00255] The motion information list in accordance with the present invention can store motion information generated in the current UPU.

[00256] FIG. 10 is a flowchart illustrating an inter-prediction method using a motion information list according to the present invention.

[00257] With reference to FIG. 10, when encoding/decoding of a new UPU starts, the motion information list initialization step is a step of deleting all the information in the motion information list or returning it to the default value.

[00258] The motion information list prediction step is a step of predicting motion information to be input into the motion information list and adding it to the motion information list.

[00259] Here, the motion information list prediction step may add a plurality of predicted motion information to the motion information list.

[00260] The inter-prediction step includes a motion information prediction step and is a step of predicting a current block through a reference picture.

[00261] The motion information adding step is a step of adding motion information obtained as a result of inter-prediction to the motion information list. According to an embodiment, the step of adding motion information may be omitted or changed. For example, when the ternary partitioning mode is executed, the step of adding motion information may be omitted. That is, when blocks resulting from partitioning in the diagonal direction share the same motion information list in the ternary partitioning mode, the step of adding motion information can be omitted.

[00262] The inter-prediction step and the motion information adding step may be performed in units of blocks and may be performed for all blocks in the corresponding UPU.

[00263] After checking whether execution has completed for all blocks in the UPU, when execution is not completed, the process moves to the next block so that inter-prediction can be performed.

[00264] When inter-prediction is performed on all blocks in the UPU and the UPU motion information list is no longer used, the motion information list may be initialized.

[00265] FIG. 11 is a flowchart illustrating an inter-prediction method using a motion information list. A description of each step illustrated in the flowchart of FIG. 11 may be the same as the description of FIG. 10.

[00266] However, the time point at which the motion information list prediction step according to FIG. 11 may differ from the time point according to FIG. 10.

[00267] In FIG. 10, the motion information list prediction step may be performed after the motion information list initialization step is performed. That is, the motion information list prediction step can be executed together with the motion information list initialization step, and thus, the motion information list prediction step can be executed when the UPU is changed.

[00268] In FIG. 11, the motion information list prediction step may be performed after the motion information adding step is performed. That is, motion information list prediction can be performed whenever motion information is added to the motion information list.

[00269] FIG. 11 differs from Fig. 10 in that the additional motion information can be predicted using the motion information stored in the current motion information list.

[00270] Moreover, in the case of FIG. 11, the predicted motion information can also be continuously updated or added to the motion information list by predicting more efficient candidates, but prediction of the motion information list is performed on each block, so the computation amount of the system may increase.

[00271] In the example flowcharts of FIGS. 10 and 11, the order of each step may vary. When encoding/decoding a block of another UPU in a situation where encoding/decoding of the current UPU is not completed, each step in FIG. 10 and 11 may be applied or omitted in different orders.

[00272] When there is no spatial reference relationship between blocks at a UPU boundary, as in the case where the UPU is a picture unit, a slice unit, or a tile unit, the encoding/decoding order cannot pass between UPUs that are different from each other. In this case, when encoding/decoding of the current UPU is not completed, encoding may be performed in the same UPU even after moving to the next block.

[00273] However, when a UPU is divided into multiple units within the same picture, slice, or tile, a case in which the next encoding/decoding block belongs to another UPU may occur even when encoding/decoding is not completed in the current UPU according to the encoding/decoding sequence. In this case, UPUs different from each other may have different motion information lists, and encoding information of the current block may be stored in the motion information list of the UPU to which the current block belongs. In this case, the motion information list can also be predicted from the motion information list stored in the other UPU to date.

[00274] Meanwhile, the motion information list prediction step may be performed at both the motion information list initialization time and the motion information adding time.

[00275] FIG. 12 is a flowchart illustrating an inter-prediction method in which motion information list prediction is performed at a motion information list initialization time and at a motion information adding time. A description of each step illustrated in the flowchart of FIG. 12 may be the same as in FIG. 10.

[00276] An inter-prediction method using a motion information list has been described in FIG. 10-12. The inter-prediction stage in FIG. 10-12 may be replaced by the IBC prediction step, and the block vector generated by the IBC prediction step may be included in the motion information list. In the following description, it is meant that inter-prediction includes IBC prediction.

[00277] Meanwhile, when using a shared merge list in IBC prediction, the step of adding motion information may be omitted.

[00278]

[00279] FIG. 13 and 14 illustrate an encoder and a decoder including a motion information list predictor.

[00280] With reference to FIG. 13 and 14, the inter-prediction module performs inter-prediction on the current block by means of the reference picture. Here, the inter-prediction module may perform inter-prediction by accessing the motion information list.

[00281] The motion information list adding module may add motion information generated as a result of inter-prediction to the motion information list.

[00282] The motion information list initialization module may initialize information stored in the motion information list in accordance with changing the UPU or creating a new motion information list.

[00283] The motion information list prediction unit can predict the motion information and store the motion information in the motion information list. Here, various types of information can be accessed according to the motion information list prediction method performed by the motion information list prediction unit.

[00284] Connection (A) shows the connection between modules in the case that the motion information list prediction module uses information of the current block, such as the spatial and temporal position of the current block; connection (B) shows the connection between modules in the case that the motion information list prediction module uses information of blocks spatially and temporally adjacent to the current block, or reference picture information with various types of information that can be accessed by the current block; and connection (C) shows the connection between the modules in the case that the motion information list prediction module uses information stored in the current motion information list. Therefore, at least one of the connections (A), (B) and (C) may be omitted according to the prediction method performed by the motion information list prediction unit.

[00285] Also, as shown in FIG. 10, the motion information list prediction unit may be executed when the motion information list is initialized. In this case, the motion information list prediction unit may operate by receiving a signal from the motion information list initialization unit via connection (D). As shown in FIG. 11, when the motion information list prediction unit operates regardless of the initialization of the motion information list, connection (D) may be omitted.

[00286] Meanwhile, the motion information encoding unit in FIG. 13 can encode motion information generated as a result of inter-prediction. The motion information decoding unit shown in FIG. 14 decodes the signal encoded by the motion information encoding unit according to FIG. 13, and allows inter-prediction to be performed in the same way as an encoder using the decoded signal.

[00287]

[00288] An indicator indicating whether to apply the motion information list during inter-prediction may be transmitted in a parameter set, such as a sequence parameter set or a picture parameter set, a tile header, a slice header, and the like.

[00289] FIG. 15 is a diagram illustrating an embodiment that performs signaling including an indicator indicating whether the motion information list should be applied to sequence parameter set (SPS) syntax.

[00290] FIG. 16 is a diagram illustrating an embodiment that performs signaling including an indicator indicating whether the motion information list should be applied to picture parameter set (PPS) syntax.

[00291] FIG. 17 is a diagram illustrating an embodiment that performs signaling including an indicator indicating whether the motion information list should be applied to the slice header syntax.

[00292] In FIG. 15-17, amvol_enable_flag is information indicating whether inter-prediction using the motion information list is enabled. When amvol_enable_flag is true, it indicates that inter-prediction using the motion information list is enabled, and when it is false, it indicates that inter-prediction using the motion information list is not enabled.

[00293] In addition, amvol_prediction_flag is information indicating whether motion information list prediction is performed. That is, amvol_prediction_flag may indicate whether the motion information list prediction step of FIG. 10-12. amvol_prediction_flag can only be signaled when amvol_enable_flag is true.

[00294] Meanwhile, when amvol_enable_flag and amvol_prediction_flag are signaled in the slice header, as in the example in FIG. 17, signaling is performed when the slice type is not I-slice. This is because the I-slice type slice does not perform inter-prediction, so inter-prediction using the motion information list is not performed. However, when IBC is executed in a slice of type I-slice and a list of motion information is available in the IBC, amvol_enable_flag may be signaled. In addition, when IBC is performed on a slice of type I-slice and motion information list prediction is available, amvol_prediction_flag may be signaled.

[00295]

[00296] Next, a motion information list prediction method according to the present invention will be described.

[00297] In this specification, the current UPU may refer to the UPU to which the current block belongs, and the current motion information list may refer to the motion information list of the current block.

[00298] In addition, motion information list prediction means predicting motion information for inclusion in an initialized or newly generated motion information list.

[00299] The motion information of the current motion information list can be predicted using an area in which encoding/decoding is completed earlier than the current UPU (ie, a pre-recovered area).

[00300] Since image motion information has a trend similar to that of a spatially and temporally contiguous region, the current UPU may have motion information similar to other spatially and temporally contiguous regions. Therefore, by referring to the motion information in the previously reconstructed area, the motion information of the motion information list of the current UPU can be predicted.

[00301] For example, there may be a method for predicting motion information of a motion information list from a region adjacent in space and time to a current block, and a method for predicting motion information of a motion information list of the current UPU from a motion information list of a previously recovered UPU.

[00302]

[00303] 1. A method for predicting motion information of a list of motion information from a region adjacent in space and time to the current block

[00304]

[00305] It is possible to predict motion information of the current motion information list from regions contiguous in space and time and belonging to UPUs different from the current UPU including the current block.

[00306] FIG. 18 is an example of motion information prediction of a current motion information list from a region adjacent in time to the current block.

[00307] In FIG. 18 assumes that the UPU is a picture unit. Therefore, when the picture changes, the motion information list can also be initialized.

[00308] FIG. 18 illustrates a method for predicting motion information of a motion information list (AMOVL) from a reference picture accessed by the current picture. Here, the reference picture is a previously reconstructed picture and may contain motion information used to restore the picture.

[00309] With reference to FIG. 18, motion information can be predicted from a corresponding block (hereinafter referred to as a “temporal neighboring block”) of a reference picture that is spatially identical but temporally different from the current encoding block (for example, CU, PU, macroblock, CTU, etc. ) to be encoded/decoded in the current picture, and can be added to the current motion information list.

[00310] Since the motion information list is initialized at the time when the first encoding block of the current picture is restored, there should be no information stored in the motion information list. However, in the example in FIG. 18, to which the present invention is applied, it can be seen that the motion information A', B' and C' derived from the temporary adjacent blocks of the reference picture are added to the motion information list.

[00311] FIG. 19 is a diagram illustrating an example of motion information prediction of a current motion information list from a region spatially adjacent to the current encoding block.

[00312] In FIG. 19, it is assumed that the UPU is a slice unit. Therefore, there can be many UPUs in one picture.

[00313] FIG. 19 shows a method for predicting motion information of a motion information list (AMOVL) of a block spatially adjacent to a current encoding block (hereinafter referred to as a “spatial adjacent block”).

[00314] With reference to FIG. 19, UPU 0 consists of three blocks and corresponds to a pre-recovery area that has already been recovered.

[00315] Since the motion information list is initialized at the time when the first encoding block of the UPU 1 is recovered, there should be no information stored in the motion information list. However, in the example in FIG. 18, to which the present invention is applied, the motion information of the motion information list can be predicted by referring to the motion information of a region spatially adjacent to the current encoding block from the previously reconstructed UPU 0. Therefore, it can be seen that the motion information of A and B are added to the list UPU 1 traffic information.

[00316] Meanwhile, the description above has been given based on the encoding block according to FIG. 18 and 19, but may be described in terms of a coding tree unit (CTU), a coding unit (CU), a prediction unit (PU), a transform unit (TU), a macroblock, or a predefined block size.

[00317]

[00318] The encoding block may store motion information in units of subblocks. Accordingly, various motion information may be provided in subblock units, and the motion information may be accessed regardless of the partition type of the encoding block.

[00319] Even in the case of predicting a list of motion information from a region adjacent in space and time, a subblock of a spatially and time adjacent encoding block can be accessed. Here, since accessing all sub-blocks requires a large amount of computation, motion information list prediction can be performed by accessing a sub-block having a predetermined range or position. A representative value of n sub-blocks can be used instead of the minimum unit, so that the motion information of all sub-blocks is not stored.

[00320] As an example, when the subblock size is 4x4, four subblocks belong to the 8x8 area. By selecting a representative value from four sub-blocks and storing only one motion information in an 8×8 area, it is possible to reduce the memory usage for storing the sub-block motion information. Here, motion information list prediction may refer to motion information specified as representative in the 8x8 area.

[00321] The range for selecting the representative value of the subblocks can be set in various sizes, such as 4x4, 8x8, 16x16, and the like. A method for selecting a representative value from sub-blocks may include a method for using a fixed position in a selection range of the representative value, a method for considering frequency of occurrence, a method for using an average value, and the like. Moreover, the representative value may be determined using at least one of a weighted sum, a weighted average, a median, a minimum value, and a maximum value, in addition to the average value.

[00322]

[00323] When predicting a motion information list from a time adjacent region, since the picture of the temporary neighboring block is different from the current picture, and the reference picture of the temporary neighboring block is different from the reference picture of the current block, the temporal distance indicated by the motion information may vary.

[00324] For example, in the case where the current picture is POC 4, the temporary neighbor picture accessed to predict the motion information list is POC 8, the current block reference picture is POC 8, and the temporary neighboring block reference picture is POC 1 , the temporal distance between the current picture and the reference picture of the current block has a difference of four with respect to POC, and the temporal distance between the picture of a temporary neighboring block and the reference picture of a temporary neighboring block has a difference of seven with respect to POC. In addition, since the current block accesses the future picture, and the temporal neighboring block accesses the past picture, it can be seen that the temporal directions of the access are also opposite to each other.

[00325] Therefore, it is necessary to predict and correct the change in motion information in time domains. This is called motion information scaling.

[00326] When motion information list prediction is performed from a time-contiguous region, motion information scaling may also be applied to the motion information accessed to predict the motion information list.

[00327] Even in the case of predicting a list of motion information from a temporary adjacent block, an increase in encoding efficiency can be expected by scaling the motion information.

[00328] However, scaling motion information can be computationally intensive. Therefore, when performing motion information list prediction, scaling of motion information may be omitted, or motion information requiring scaling of motion information may not be used for prediction.

[00329] When there is slight motion of a temporary neighboring block, scaling of the motion information may not be required.

[00330] Alternatively, motion information scaling may be omitted when the time interval between the current picture and the reference picture of the current block is equal to the time interval between the picture of the temporary neighboring block and the reference picture of the temporary neighboring block or less than a predetermined range.

[00331] As such, only motion information that does not require scaling of motion information is used for prediction, and accordingly, increased computation due to scaling of motion information can be avoided.

[00332] Meanwhile, motion information that requires motion information scaling may be assigned a lower priority than motion information that does not require motion information scaling in prediction.

[00333]

[00334] 2. Method for predicting motion information of a motion information list from a motion information list previously recovered by the UPU

[00335]

[00336] The present method is a method for performing motion information list prediction of a current UPU using the motion information list of a previously reconstructed UPU.

[00337] UPUs may have motion information lists that are different from each other, and spatially and temporally adjacent UPUs may have motion information lists that are similar to each other. Therefore, the current UPU can predict the motion information of the current motion information list by referring to the motion information list of the space-time adjacent UPU that has been previously reconstructed.

[00338]

[00339] FIG. 20 is a diagram illustrating an example of a method for performing prediction of a current motion information list with reference to a motion information list previously retrieved by the UPU.

[00340] In FIG. 20 shows a point in time when the first encoding block of the UPU 1 is restored, and the motion information list can be initialized at this point in time, so that the motion information generated from the current UPU (UPU 1) cannot be added.

[00341] In the example of FIG. 20, to which the present invention is applied, by referring to the motion information list previously recovered by UPU 0, prediction of the motion information list is performed by adding the motion information of the UPU 0 motion information list to the UPU 1 motion information list.

[00342] After inter-prediction of the first block of the current picture is completed, the motion information of the first block can be added to the motion information list. Here, the corresponding motion information can be set to have the lowest index value in the motion information list. The index values of motion information existing in the existing motion information list may be increased by one and thus stored.

[00343] Alternatively, the motion information of the first block may be set to have a predetermined index value in the motion information list. The index value of motion information existing in the existing motion information list may be maintained when increased by one.

[00344]

[00345] Meanwhile, when the entire picture is a UPU, the last block of the previously reconstructed picture is encoded/decoded, and then the final motion information list in which the block motion information is stored is used to predict the motion information list of the first block of the current picture.

[00346] That is, all or part of the motion information stored in the final UPU motion information list of the previously reconstructed picture is used to predict or initialize the motion information list of the current UPU, which is the current picture. Here, the UPU of the previously reconstructed picture may be called a reference UPU.

[00347] The motion information list may not store motion information from the current picture before inter-prediction of the first block of the current picture is performed. This is because there is no motion information in the current picture. Here, the motion information list can be predicted or initialized by storing some or all of the motion information stored in the final motion information list of the reference UPU in the current motion information list. The motion information stored in the current motion information list through prediction or initialization of the motion information list can be used for inter-prediction of the first block of the current picture.

[00348]

[00349] When the current motion information list is predicted from the motion information list of the pre-recovered area, the intermediately configured motion information list can be accessed instead of the finally configured motion information list in the pre-recovered area.

[00350] The motion information list can accumulate and store motion information generated in the corresponding UPU, and can also delete the stored motion information. Therefore, as encoding/decoding is performed, the stored information may change. When predicting or initializing the current motion information list, in the case where the location of the encoding block for performing prediction by the current motion information list is distant from the generation location of the motion information finally stored by the motion information list in the pre-recovered area accessed by the current motion information list, the efficiency motion information list predictions may be reduced.

[00351] For example, when the UPU is a picture unit, motion information finally stored in the motion information list may be motion information generated from a coding block at the bottom right of the picture. Here, when the amount of motion information stored in the motion information list is limited, the motion information generated near the upper left end, which is the initial part of the picture from the finally stored motion information, is removed from the motion information list, and the motion information near the lower right end , which is the end part of the picture, can be stored in the motion information list. Since the first encoding block of the current UPU corresponds to the upper left region of the picture, the motion information generated from the lower right region of the reference picture has low correlation, and the prediction efficiency is low. When predicting or initializing a motion information list, encoding efficiency may be higher when accessing the motion information list while storing the information adjacent to the upper left region, instead of a previously reconstructed motion information list that is finally created, than when accessing the final motion information list.

[00352] However, memory usage is significantly higher when the motion information list is stored at all stages. Accordingly, after copying and storing a predetermined motion information list at a specific time so that memory usage can be reduced, a motion information reference list buffer can be separately used, which can be used to predict or initialize the motion information list.

[00353] For example, motion information lists of the upper left and lower right areas of the UPU may be stored in a motion information reference list buffer.

[00354]

[00355] In addition, when the motion information list of the pre-recovered picture is used to predict the motion information list, the current picture is different from the pre-recovered picture, and the reference picture of the current block is different from the reference picture referred to by the motion information in the motion information list of the pre-recovered picture. . Here, since the prediction efficiency may be reduced due to the difference in time distance between the pre-reconstructed picture and the reference picture accessed by the motion information, correction such as motion information scaling and the like can be used.

[00356]

[00357] In addition, the above method may assign a UPU to address. As a method for assigning a UPU to address, there is a method for allowing an encoder and a decoder to access the same UPU by transmitting and receiving an encoded signal, and a method for skipping additional signal transmission and reception by selecting the UPU in a predetermined manner.

[00358] Although in FIG. 20 describes a method for copying an entire motion information list of a reference UPU as a method for predicting a current motion information list, a method for copying only part of the motion information from a motion information list to a current motion information list may be applied.

[00359] As an example, only motion information below a predetermined index from the motion information list of the reference UPU may be added to the current motion information list.

[00360]

[00361] 3. A method for predicting motion information of a current motion information list from motion information previously included in the current motion information list

[00362]

[00363] When the amount of motion information stored in the motion information list is insufficient, the insufficient amount of motion information list can be predicted and added from the current motion information list.

[00364] Additional prediction of the motion information of the current motion information list from the motion information previously included in the current motion information list may be performed at at least one of the times after the motion information is added to the motion information list, the time that is added, and the time the time at which motion information is generated in the encoding block before the motion information is added to the motion information list.

[00365]

[00366] FIG. 21 is a diagram illustrating a method for performing motion information list prediction from motion information stored in a current motion information list.

[00367] With reference to FIG. 21, it can be seen that the motion information A generated by the inter-prediction of the first encoding block is added to the motion information list (AMVOL update). This means a state in which only one motion information is stored in the motion information list. Therefore, when inter-prediction is performed by the motion information list, encoding efficiency may deteriorate.

[00368] In FIG. 21, it can be seen that prediction of the motion information list is performed before performing inter-prediction of the next encoding block (or after updating the motion information list). The amount of motion information stored in the motion information list can be increased by predicting the motion information A' and A'' from the motion information A stored in the current motion information list and storing it in the motion information list. By increasing the amount of motion information in the current motion information list, the performance of inter-prediction using the motion information list can be improved.

[00369]

[00370] Further, motion information existing in the current motion information list is called existing motion information, and the newly predicted motion information is called predicted motion information.

[00371] The following methods 1)-3) are examples of a method for deriving predicted motion information using existing motion information.

[00372]

[00373] 1) A method for transforming a motion vector of existing motion information and outputting predicted motion information

[00374]

[00375] A motion vector represents, as motion, the spatial distance between a block using the corresponding motion information and a region to be accessed. Therefore, when the motion vector is transformed, the area to be addressed changes.

[00376] For example, there is a method for modifying a motion vector of existing motion information using a predetermined method.

[00377] The method for modifying the motion vector may be at least one of adding displacement, scaling, and flipping.

[00378] Offset addition is a method of modifying a motion vector by adding a predetermined offset to the motion vector.

[00379] As an example, a motion vector can be expressed as MV(x, y) having an x-axis offset and a y-axis offset, and by adding a predetermined offset dx, dy to MV(x, y), the modified vector can be generated movements MV'(x+dx, y+dy). Here, dx and dy can be integers, and dx and dy can be values different from each other.

[00380] Scaling is a method of modifying a motion vector by multiplying a predetermined magnification factor sx and sy by the motion vector MV(x, y). MV'(sx*x, sy*y) can be generated, which is a motion vector modified by scaling. By using different magnification factors, different modified motion vectors can be generated. Here, sx and sy may be integers, and sx and sy may be values different from each other.

[00381] Mirroring is a method of modifying a motion vector by reversing the direction while maintaining the size of the motion vector. For example, when mirroring the x-axis and y-axis is applied to the motion vector MV(x, y), it is possible to generate MV'(-x, -y), which is a modified motion vector. By defining the axis to be used, various modified motion vectors can be generated.

[00382]

[00383] 2) A method for converting reference information of existing motion information and outputting predicted motion information

[00384]

[00385] The reference information is information about a reference picture including a region that is accessed in inter-prediction. By changing the reference information included in the motion information, the reference picture is changed so that the area being accessed can change. Even in the case of the same motion vector, when the reference picture changes, the information of the pixel being accessed may change, and thus the result of the inter-prediction may change. Here, the motion vector is corrected using the time axis distance between the current picture and the reference picture of the existing motion information and the time axis distance between the current picture and the changed reference picture, thereby improving the prediction accuracy of the motion information.

[00386] FIG. 22 is an example illustrating a process of deriving predicted motion information by changing a reference picture of existing motion information and adjusting the motion vector accordingly.

[00387] With reference to FIG. 22, the current picture is located at point t on the time axis, and a reference picture that can be accessed by the current picture is located at points t-k, t-m and t+n on the time axis. The current motion information list has motion vector A referring to L0 reference picture 0, which is the reference picture at time t-m with index zero.

[00388] The motion information A may be adjusted to the distance (counter picture, POC) on the time axis between the current picture and each reference picture, assuming that the object's motion is close to linear within a short period of time.

[00389] When the reference information is changed to L0 reference picture 1, which is the reference picture at time t-k, and L1 reference picture 0, which is the reference picture at time t+n, the motion information A can be adjusted in A' and A '', respectively, taking into account the distance on the time axis between the picture and the reference picture. The predicted motion information output as described above may be added to the motion information list.

[00390]

[00391] 3) Method for deriving predicted motion information using a plurality of existing motion information

[00392]

[00393] When two or more motion information are present in the motion information list, predicted motion information can be output by partially using each of the existing motion information or using the average of two or more motion information.

[00394] Additionally, at least one of the statistical values, such as a weighted sum, a weighted average, a median, a minimum value, a maximum value, and the like, may be used in addition to the average.

[00395] Meanwhile, the reference information of any one of the existing motion information can be used as the reference information of the predicted motion information.

[00396] Alternatively, predicted motion information having reference information different from the reference information of existing motion information may be output.

[00397] As an example, reference information may be signaled in the top parameter set, slice header or the like, and the picture indicated by the first index of the reference picture list may be used as the reference information of the predicted motion information.

[00398]

[00399] 4. Method for predicting predetermined motion information as motion information of a current motion information list

[00400]

[00401] This method is a method for predicting predetermined motion information as motion information of a current motion information list. Specifically, motion information determined similarly in the encoder and decoder may be added to the current motion information list.

[00402] The predefined motion information may include motion vector information having a specific motion value in the x and y directions, such as (0, 0), (0, 1), (0, -1), (1, 0) , (-1, 0) and the like.

[00403] In addition, reference information of the predetermined motion information may be determined in advance, for example, the “0” picture of the reference picture list L0 or the “0” picture of the reference picture list L1.

[00404] On the other hand, the encoder may generate a flag indicating whether or not to use the predetermined motion information and deliver it to the decoder.

[00405] When there is a plurality of predetermined motion information, the encoder may generate an identifier (or index, etc.) indicating which motion information should be applied, and transmit it to the decoder.

[00406] The decoder can determine whether the predetermined motion information should be applied and what motion information should be applied based on the transmitted information.

[00407]

[00408] There may be a case where there is no pre-recovered area that can be accessed by the current UPU, or a case where the amount of motion information that can be predicted from the pre-recovered area that is accessed is sufficient. In such cases, the above-described methods 3 and 4 can be used to predict the motion information list.

[00409]

[00410] 5. Method for eliminating candidates covered by other motion prediction methods

[00411]

[00412] A variety of inter-prediction methods can be used in encoding and decoding, and motion information included in the motion information list can be used to predict motion information in various inter-prediction methods. Here, the motion prediction candidate used by the inter-prediction method may be overlapped with the predicted motion information of the motion information list.

[00413] As an example, the motion information of a temporary fusion candidate in a fusion mode and the motion information predicted for the motion information list are identical and thus overlap with each other.

[00414] In the above case, when using the same motion information for inter-prediction, the prediction efficiency may deteriorate. Therefore, given the motion prediction method (eg, fusion candidate in fusion mode, motion vector candidate in AMVP mode, etc.) used for inter-prediction, motion information can be set to have more diverse predicted information without overlap.

[00415]

[00416] When motion prediction method candidates and predicted motion information of the motion information list overlap each other, it can be determined whether the predicted motion information of the motion information list should be used according to priority.

[00417] When the priority of motion prediction method candidates is high, the predicted motion information of the motion information list may not be used. That is, the predicted motion information may not be included in the motion information list.

[00418] In contrast, when the priority of motion prediction method candidates is low, the predicted motion information of the motion information list may be used. That is, the predicted motion information may be included in the motion information list. The motion prediction method candidate may not be included in the motion information list.

[00419] In addition, when the priority of motion prediction method candidates and the priority of predicted motion information of the motion information list are the same, the predicted motion information of the motion information list may be used or may be replaced with predetermined motion information.

[00420]

[00421] To prevent the predicted motion information of the motion prediction list and the motion prediction method candidate from overlapping, the predicted motion information list of the motion information list can be set to be output at a predetermined position that does not overlap with the position of the motion prediction method candidate block at the time when Encoding/decoding begins.

[00422] For example, a co-located CTU may be assigned, and motion information may be output from a predetermined position in the CTU.

[00423]

[00424] FIG. 23 is a diagram illustrating a motion information list prediction method that does not overlap with a motion prediction method candidate. In fig. 23, the positions C and H indicated by the diagonal pattern (diagonal pattern from the upper right end to the lower left end) may refer to the positions of temporary candidates, which can be used in inter-prediction of the current encoding block.

[00425] With reference to FIG. 23, the pre-recovered area used for motion information list prediction may be set to an area at a position different from positions C and H.

[00426] As shown in FIG. 23, the motion information of the motion information list can be set to be output in positions a, b, c, d and e except for positions C and H.

[00427] In addition, when adding motion information to the motion information list, the same motion information as the motion information of positions C or H cannot be added to the motion information list.

[00428] FIG. 24 is a diagram illustrating an embodiment of setting a position accessed to predict a list of motion information in CTUs when the positions of the motion prediction method temporary candidates are the same as the positions C and H in FIG. 23.

[00429] When configuring the reference position in CTU units in the same manner as in FIG. 24, it is possible to simplify the motion information list prediction structure using a fixed position while improving encoding efficiency by addressing a region not predicted by the existing motion prediction method.

[00430] In FIG. 24, a diagonal pattern block (a diagonal pattern block from top right to bottom to left) and a reverse diagonal pattern block (a diagonal pattern block from top left to bottom right) may indicate positions of motion information accessed to predict the current list of motion information in the combined CTU. A diagonal pattern block means a reference region having a higher priority than a reverse diagonal pattern block.

[00431]

[00432] Meanwhile, when a motion prediction candidate used by the inter-prediction method is overlapped with predicted motion information of the motion information list, the overlapped predicted motion information cannot be used for inter-prediction.

[00433]

[00434] 6. Method of using predicted motion information separately from general motion information

[00435]

[00436] In the present specification, general motion information may mean motion information added to the motion information list as motion information generated by inter-prediction, and motion information added to the motion information list in the motion information adding step of FIG. 10 and 11. The predicted motion information may mean motion information generated by motion information list prediction as described above, and may be motion information added to the motion information list in the motion information list prediction steps of FIG. 10 and 11.

[00437]

[00438] The predicted motion information may have a lower prediction efficiency of the motion information than the general motion information. Therefore, when predicted motion information has a higher priority than general motion information, encoding efficiency may be reduced. Therefore, the predicted motion information can be generated separately from the general motion information, so that the priority of the predicted motion information can be reduced or adjusted.

[00439] In addition, in the case that general motion information is added when the motion information list already had a limited maximum amount of motion information, the predicted motion information may be deleted first.

[00440]

[00441] FIG. 25 and 26 are diagrams illustrating an embodiment of a method for separately using predicted motion information and general motion information. The motion information may be added to the motion information list in FIG. 25 and 26 according to the first-in-first-out (FIFO) rule, and the size of the traffic information list is limited to five. Here, the size of the motion information list also includes the size of the sub-motion list.

[00442] With reference to FIG. 25, there may be a motion information list (AMVOL) storing general motion information, and a sub-motion information list (sub-AMVOL) storing a list of predicted motion information.

[00443] Before performing inter-prediction of the first encoding block, no information is stored in the motion information list, and the motion information A', B' and C' predicted from the reference picture may be stored in the motion information sub-list.

[00444] Then, motion information can be added to the motion information list as inter-prediction of each encoding block is performed.

[00445] Here, when the maximum size of the motion information list is reached, the motion information is first removed from the motion information sub-list in which the predicted motion information is stored, and new motion information can be added to the motion information list.

[00446] Meanwhile, information indicating whether motion information sub-list, motion information list size information, or motion information sub-list size information is used may be information preset in the encoder/decoder.

[00447] Alternatively, information indicating whether motion information sub-list, motion information list size information, or motion information sub-list size information is used may be information signaled from the encoder to the decoder.

[00448] Here, the size of the motion information list may be limited to a preset range. For example, the preset range could be from 0 to 5.

[00449] In addition, the size of the motion information list may be limited by information signaled from the encoder to the decoder. Information indicating the size of the motion information list may be signaled at a higher bitstream level, such as a sequence parameter set, a picture parameter set, a slice header, a tile header, a tile group header, and the like.

[00450]

[00451] FIG. 26 is a diagram illustrating an embodiment in which one motion information list is used without using a motion information sub-list, unlike FIG. 25.

[00452] In the example of FIG. 26, the motion information list may be managed in a FIFO manner. That is, the motion information list uses a method of adding the generated motion information to the last part of the motion information list and first deleting the previous motion information that is entered first when the maximum size of the motion information list is exceeded.

[00453] In other words, when the amount of motion information stored in the motion information list reaches the maximum value, the motion information specified in the last index of the motion information list is deleted, and the newly outputted motion information is added to the motion information list. Here, the index of motion information included in the motion information list may increase by one. The newly added motion information may be added to the motion information list so as to be indicated by index 0.

[00454]

[00455] In addition, motion information stored in the motion information list may have a higher priority the lower the index.

[00456] Here, the motion information stored by the motion information list prediction can be processed separately from the general motion information of the motion information list generated and stored in the current UPU.

[00457] Since predicted motion information has a low priority, when general motion information is added again, an index lower than in the case of motion information in the predicted motion information list may be assigned.

[00458] In addition, when the maximum size of the motion information list is reached, the predicted motion information may be preferably deleted, and new motion information may be added to the motion information list.

[00459]

[00460] In this case, the lower the index, the higher the priority, as described earlier. On the contrary, the higher the index, the lower the priority.

[00461] Therefore, the FIFO method for the motion information list can also be performed as described below. That is, when the amount of motion information stored in the motion information list reaches the maximum value, the motion information indicated by index 0 of the motion information list can be deleted, and the newly outputted motion information can be added to the motion information list. Here, the index of motion information included in the motion information list may be decreased by one. The newly added motion information may be added to the motion information list so as to be indicated by the largest index among the motion information included in the motion information list.

[00462] Meanwhile, when the newly added motion information is stored in the motion information list, the previously stored motion information that is overlapped is deleted from the motion information list, and the newly output motion information can be included in the motion information list. Here, the motion information indexes of the motion information list having an index value greater than the deleted motion information may be decreased by one. The newly added motion information may be added to the motion list so as to be indicated by the largest index among the motion information included in the motion information list.

[00463]

[00464] Motion information included in the motion information list may have priority when used to predict motion information. The motion information may be implicitly expressed according to the order in which the motion information is stored in the motion information list, the priority is explicitly set as candidates when performing inter-prediction using the motion information list, or it may be selectively used by priority.

[00465] In addition, since the motion information list may have a limited size, when the limited size is reached, the motion information stored in the motion information list can be deleted and new motion information can be added according to priority.

[00466]

[00467] Meanwhile, the predicted motion information may have a prediction efficiency lower than the prediction efficiency of normal motion information. However, since this is not the case in all cases, the priority of the predicted motion information can be reconfigured.

[00468]

[00469] Additional information may be used to reconfigure the priority of the predicted motion information.

[00470] The motion information list may include additional information in addition to the motion information. Here, additional information may mean information indicating the inter-prediction efficiency of motion information included in the motion information list, and may also be called potential prediction information. For example, the additional information may be information derived based on the number of occurrences of the same motion information in the UPU.

[00471] Additional information may represent the relative variability of encoding efficiency when using the motion information list for inter-prediction.

[00472] As a method for determining additional information, there may be a determining method based on the frequency of occurrence of motion information, a determining method based on the prediction efficiency using motion information, a determining method based on the location where motion information is output, and a determining method based on that whether motion information should be used.

[00473] A frequency-based determination method for motion information is a method for determining additional information based on the number of times the same motion information as the motion information stored in the motion information list is generated in the UPU.

[00474] A method for determining based on prediction efficiency using motion information is a method for determining additional information based on the distribution of residual signal energy or the average value of residual signal energy in a coding block that uses motion information stored in a motion information list.

[00475] A method for determining based on the location from which motion information is derived is a method for determining additional information based on the spatial and temporal distance between the current encoding block and the encoding block in which motion information is output stored in the motion information list.

[00476] At the same time, the priority of the predicted motion information can be reset based on whether the predicted motion information is used for inter-prediction. The reason is that the corresponding predicted motion information is likely to be used in the future when it is used for inter-prediction.

[00477] The information needed to reprioritize the predicted motion information may be information that is preset in the encoder/decoder or signaled from the encoder to the decoder.

[00478]

[00479] FIG. 27 is a flowchart illustrating an image decoding method according to an embodiment of the present invention.

[00480] With reference to FIG. 27, the image decoding apparatus may generate a candidate list including motion information output from a spatial neighbor block and a temporal neighbor block adjacent to the current block (S2710).

[00481] Here, the candidate list may be any one of a merge mode merge candidate list, an AMVP mode motion vector candidate list, an IBC mode merge candidate list, an IBC mode block vector candidate list, and a shared IBC mode merge list .

[00482] In addition, the image decoding apparatus may output motion information of the current block using the candidate list (S2720).

[00483] The image decoding apparatus may generate a current block prediction block using the output motion information (S2730). In detail, the image decoding apparatus may generate a current block prediction block by performing inter-prediction or IBC prediction.

[00484] In addition, the image decoding apparatus may update the output motion information in the motion information list (S2740). Step S2740 may be the same as the motion information adding step in FIG. 10 and 11 described above.

[00485] Here, a candidate list may be generated including at least one of the motion information included in the motion information list updated in the block decoded before the current block. Here, the motion information list may be the above-described AMVOL or HMVP list.

[00486] Meanwhile, when decoding of the predetermined area is completed, so that the area in the motion information list is changed, the image decoding apparatus may initialize the motion information list. Here, the predefined area may be any one of a block consisting of one or more CUs or a block consisting of one or more CTUs. The above-described initialization may be the same as the motion information initialization step in FIG. 10 and 11.

[00487] Meanwhile, the motion information list may be limited to a predetermined size. Here, the predefined size may be six.

[00488] Meanwhile, when there is a plurality of motion information in the motion information list updated in the block decoded before the current block, the image decoding apparatus may include the average of at least two or more motion information from the plurality of motion information into the candidate list.

[00489] Meanwhile, when the motion information of the motion information list updated in the block decoded before the current block is the same as the motion information previously included in the candidate list, the image decoding device may resolve not to include the motion information of the motion information list to the list of candidates.

[00490] In addition, when the current block is an IBC prediction mode and the candidate list is a shared merge list, a method for updating the output motion information in the motion information list may be omitted.

[00491] Meanwhile, when the amount of motion information stored in the motion information list is a preset value, the image decoding apparatus can delete the motion information stored first in the motion information list and store the motion information output in step S2720.

[00492] The image decoding method has been described above with reference to FIG. 27. Since the image encoding method of the present invention can be described similarly to the image decoding method described with reference to FIG. 27, redundant description is omitted.

[00493] The bit stream generated by the image encoding method of the present invention can be temporarily stored in a computer-readable non-transitory recording medium and can be decoded by the above-described image decoding method.

[00494]

[00495] The above embodiments may be performed in the same manner in an encoder and a decoder.

[00496] At least one or a combination of the above embodiments may be used for video encoding/decoding.

[00497] The sequence applied to the above embodiment may be different for the encoder and decoder, or the sequence applied to the above embodiment may be the same in the encoder and decoder.

[00498] The above embodiment may be performed for each luma signal and chrominance signal, or the above embodiment may be identically performed for luma and chrominance signals.

[00499] The block shape to which the above embodiments of the present invention are applied may be a square shape or a non-square shape.

[00500] The above embodiment of the present invention can be applied depending on the size of at least one of a coding block, a prediction block, a transform block, a block, a current block, a coding unit, a prediction unit, a transform unit, a unit, and a current unit. Here, the size may be defined as a minimum size or a maximum size or both to apply the above embodiments, or may be defined as a fixed size to which the above embodiment is applied. Moreover, in the above embodiments, the first embodiment may be applied to the first size, and the second embodiment may be applied to the second size. In other words, the above embodiments can be used in combination depending on the size. Moreover, the above embodiments may be applied when the size is equal to or greater than the minimum size and equal to or less than the maximum size. In other words, the above embodiments can be applied when the block size falls within a certain range.

[005001] For example, the embodiments described above may be applied when the current block size is 8x8 or larger. For example, the above embodiments may be applied when the current block size is 4×4 or larger. For example, the above-described embodiments may be applied when the current block size is 16×16 or larger. For example, the above embodiments may be applied when the current block size is equal to or greater than 16×16 and equal to or less than 64×64.

[00502] The above-mentioned embodiments of the present invention can be applied depending on the time level. To identify the time layer to which the above embodiments may be applied, a corresponding identifier may be signaled, and the above embodiments may be applied to the specified time layer identified by the corresponding identifier. Here, the identifier may be defined as the lowest level or the highest level, or both, to which the above embodiment may apply, or may be defined to indicate a specific level to which this embodiment applies. In addition, a fixed time level to which the embodiment applies can be defined.

[00503] For example, the embodiments described above may be applied when the time level of the current image is the lowest level. For example, the above embodiments may be applied when the temporal layer ID of the current image is equal to or greater than 1. For example, the above embodiments may be applied when the temporal layer of the current image is the highest level.

[00504] The slice type or tile group type to which the above embodiments of the present invention are applied can be determined, and the above embodiments can be applied depending on the corresponding slice type or tile group type.

[00505] In the above-described embodiments, the methods are described on the basis of flowcharts with a sequence of steps or modules, but the present invention is not limited to the order of the steps, and rather, some steps may be performed simultaneously or in a different order with other steps. In addition, one skilled in the art will appreciate that the steps in the flowcharts are not mutually exclusive and that other steps may be added to the flowcharts or some of the steps may be deleted from the flowcharts. operations without affecting the scope of the present invention.

[00506] Embodiments include various aspects of the examples. All possible combinations for the various aspects may not be described, but those skilled in the art will recognize the various combinations. Accordingly, the present invention may include all substitutions, modifications and changes within the scope of the claims.

[00507] Embodiments of the present invention may be implemented in the form of program instructions that are executed by various computer components and recorded on a computer-readable recording medium. The computer-readable recording medium may include, individually or in combination, program instructions, data files, data structures, etc. Program instructions recorded on a computer-readable recording medium may be specifically designed and constructed for the present invention or well known to one skilled in the art of computer software technology. Examples of computer-readable recording media include magnetic recording media such as hard disks, floppy disks and magnetic tapes; optical storage media such as CD-ROM or DVD-ROM; magneto-optical media such as floptic disks; and hardware devices such as read-only memory (ROM), random access memory (RAM), flash memory, etc., which are specifically structured to store and implement a software instruction. Examples of program instructions include not only mechanical language code formatted by a compiler, but high-level language code that can be implemented by a computer using an interpreter. Hardware devices may be configured to operate one or more software modules or, alternatively, to perform processes in accordance with the present invention.

[00508] Although the present invention has been described in terms of specific objects, such as detailed elements, as well as limited embodiments and drawings, they are provided only to facilitate a more general understanding of the invention, and the present invention is not limited to the above embodiments. Those skilled in the art to which the present invention relates will appreciate that various modifications and changes may be made based on the above description.

[00509] Therefore, the spirit of the present invention should not be limited to the embodiments described above, and the entire scope of the appended claims and their equivalents will be within the scope and spirit of the invention.

Industrial applicability

[00510] The present invention can be used to encode or decode an image.

1. A method for decoding an image, containing:

generating a candidate list including motion information derived from a spatial neighbor block and a temporal neighbor block adjacent to the current block;

outputting movement information of the current block using the list of candidates;

generating a current block prediction block using the output motion information; And

updating the output motion information in the motion information list,

wherein generating the candidate list is performed so as to include at least one of the motion information included in the updated motion information list in the block decoded before the current block.

2. The method according to claim 1, wherein the motion information list is initialized when decoding of the predetermined area is completed, so that the area changes.

3. The method of claim 2, wherein the predefined area is any one of a block consisting of one or more coding units (CUs) or a block consisting of one or more coding tree units (CTUs).

4. The method according to claim 1, wherein when there is a plurality of motion information in the updated motion information list in the block decoded before the current block, generation of the candidate list is performed so as to include the average of at least two or more motion information from the plurality of motion information to the list of candidates.

5. The method according to claim 1, wherein when the motion information of the updated motion information list in the block decoded before the current block is the same as the motion information previously included in the candidate list, generation of the candidate list is performed so as not include traffic information of the traffic information list in the candidate list.

6. The method according to claim 1, wherein when the current block is an IBC prediction mode and the candidate list is a shared merge list, updating the output motion information in the motion information list is omitted.

7. The method according to claim 1, wherein the motion information list is limited to a predetermined size.

8. The method according to claim 1, wherein when the amount of motion information stored in the motion information list is a predetermined value, updating the output motion information in the motion information list includes deleting the motion information stored first in the motion information list and storing the output traffic information.

9. An image encoding method containing:

generating a candidate list including motion information derived from a spatial neighbor block and a temporal neighbor block adjacent to the current block;

outputting movement information of the current block using a list of candidates;

generating a current block prediction block using the output motion information; And

updating the output motion information in the motion information list,

wherein generating the candidate list is performed so as to include at least one information from the motion information included in the updated motion information list in the block encoded before the current block.

10. The method of claim 9, wherein the motion information list is initialized when encoding of the predetermined area is completed, so that the area changes.

11. The method of claim 10, wherein the predefined area is any one of a block consisting of one or more coding units (CUs) or a block consisting of one or more coding tree units (CTUs).

12. The method of claim 9, wherein when there is a plurality of motion information in the updated motion information list in a block encoded before the current block, generation of the candidate list is performed so as to include the average of at least two or more motion information from the plurality of motion information to the list of candidates.

13. The method according to claim 9, wherein when the motion information of the updated motion information list in the block encoded before the current block is the same as the motion information previously included in the candidate list, generation of the candidate list is performed so as not include traffic information of the traffic information list in the candidate list.

14. The method according to claim 9, wherein when the current block is an IBC prediction mode and the candidate list is a shared merge list, updating the output motion information in the motion information list is omitted.

15. The method according to claim 9, wherein the motion information list is limited to a predetermined size.

16. The method according to claim 9, wherein when the amount of motion information stored in the motion information list is a predetermined value, updating the output motion information in the motion information list includes deleting the motion information stored first in the motion information list and storing the output traffic information.

17. A computer-readable non-transitory recording medium comprising a bit stream decoded by an image decoding method, wherein the image decoding method comprises:

generating a candidate list including motion information derived from a spatial neighbor block and a temporal neighbor block adjacent to the current block;

outputting movement information of the current block using the list of candidates;

generating a current block prediction block using the output motion information; And

updating the output motion information in the motion information list,

wherein generating the candidate list is performed so as to include at least one information from the motion information included in the updated motion information list in the block decoded before the current block.

Claims (42)

1. A method for decoding an image, containing: generating a candidate list including motion information output from a neighboring block adjacent to the current block; outputting movement information of the current block using the list of candidates; And generating a prediction block of the current block using the output motion information of the current block, wherein the average of the set of candidate list movement information is added to the candidate list. 2. The image decoding method according to claim 1, additionally containing: updating the output motion information of the current block in the motion information list to be used for inter-prediction, wherein a neighboring block contains a spatially adjacent block and a temporally adjacent block. 3. The image decoding method according to claim 2, in which inter-prediction uses merge mode. 4. The image decoding method according to claim 2, in which inter-prediction uses Advanced Motion Vector Prediction (AMVP) mode. 5. The image decoding method of claim 2, wherein generating the candidate list is performed so as to include at least one of the motion information included in the updated motion information list in a block decoded before decoding for the current block. 6. The image decoding method as set forth in claim 5, wherein when the candidate list is a shared merge list, updating the motion output information of the current block in the motion information list to be used for inter-prediction is omitted. 7. The image decoding method of claim 2, wherein when the motion information of the updated motion information list in a block decoded before decoding for the current block is the same as the motion information previously included in the candidate list, generation of the candidate list is performed as follows: such as not to include the traffic information list traffic information in the candidate list. 8. The image decoding method of claim 2, wherein the motion information list is initialized when decoding of a predetermined area is completed, so that the area is changed. 9. The image decoding method of claim 8, wherein the predefined area is any one of a block consisting of one or more coding units (CU) or a block consisting of one or more coding tree units (CTU). 10. The image decoding method of claim 2, wherein when there is a plurality of motion information in the updated motion information list in a block decoded before decoding for the current block, generating a candidate list is performed so as to include an average of at least two or more information movement from said plurality of movement information to the candidate list. 11. The image decoding method according to claim 10, wherein reference information of one of at least two or more motion information is used as reference information of said average. 12. The image decoding method according to claim 2, wherein the motion information list is limited to a predetermined size. 13. The image decoding method as set forth in claim 12, wherein when the amount of motion information stored in the motion information list is a predetermined value, updating the output motion information of the current block in the motion information list includes deleting motion information that has been stored in the list motion information first, and storing the output motion information. 14. The image decoding method as set forth in claim 2, wherein when output motion information of the current block is duplicated with other motion information for the current block, the other motion information is not used as a candidate for inter-prediction for the current block. 15. The image decoding method according to claim 1, additionally containing: storing the output motion information in a motion information list to be used for the intra block copy (IBC) mode. 16. The image decoding method according to claim 15, wherein the IBC mode comprises a merge mode. 17. The image decoding method as set forth in claim 15, wherein the IBC mode comprises an enhanced motion vector prediction (AMVP) mode. 18. An image encoding method containing: generating a candidate list including motion information output from a neighboring block adjacent to the current block; And outputting movement information of the current block using a list of candidates, wherein the average of the set of candidate list movement information is added to the candidate list. 19. The image encoding method according to claim 18, additionally containing: generating a current block prediction block using the output motion information of the current block. 20. The image encoding method as set forth in claim 18, wherein a current block prediction block is generated using output information of the current block. 21. The image encoding method according to claim 18, additionally containing: updating the output motion information of the current block in the motion information list to be used for inter-prediction, wherein a neighboring block contains a spatially adjacent block and a temporally adjacent block. 22. A computer-readable medium storing computer-executable code as a bitstream, wherein the computer-executable code, when executed, causes the device to perform the image decoding method of claim 1. 23. A computer-readable recording medium storing a bit stream including computer executable code, wherein the computer executable code, when executed, causes the video decoding device to perform the following steps comprising: generating a candidate list including motion information output from a neighboring block adjacent to the current block using the prediction mode information from the computer-executable code, outputting movement information of the current block using the list of candidates; And generating a prediction block of the current block using the output motion information of the current block, wherein the average of the set of candidate list movement information is added to the candidate list.