KR102435502B1 - Method and apparatus for encoding or decoding video signal - Google Patents

Abstract

The present invention relates to a method for processing a video signal and an apparatus therefor. A processing method according to an embodiment of the present invention includes: determining a shape of a current block; determining any one or more of positions and numbers of neighboring blocks that obtain the most probable intra prediction mode of the current block according to the determined shape; and constructing a list of most probable intra prediction modes of the current block based on the determined intra prediction modes of the neighboring blocks, wherein the neighboring blocks may include left neighboring blocks and upper neighboring blocks. .

Description

A method and apparatus for encoding or decoding a video signal

The present invention relates to a method and apparatus for encoding or decoding a video signal, and more particularly, to a method for constructing a most probable intra prediction mode (MPM) list using the shape of a prediction block and information on neighboring blocks, and The present invention relates to a method and apparatus for encoding and decoding a video signal including the same.

Recently, the demand for high-resolution and high-quality images such as HD (High Definition) images and UHD (Ultra High Definition) images is increasing in various application fields. Since the amount of data increases relative to the existing image data as the image data becomes high-resolution and high-quality, when transmitting image data using a medium such as an existing wired/wireless broadband line or storing it using an existing storage medium, the transmission The cost and storage cost will increase. High-efficiency image compression techniques can be used to solve these problems that occur as image data becomes high-resolution and high-quality.

A method of predicting using information on neighboring blocks of the current block without transmitting the information of the current block as it is with image compression technology may be used. In this prediction method, pixels included in the current picture from pictures before or after the current picture are used. An inter prediction technique for predicting a value and an intra prediction technique for predicting a pixel value included in the current picture by using pixel information in the current picture may be used. In addition, various technologies exist, such as entropy encoding technology in which a short code is assigned to a value with a high frequency of occurrence and a long code is assigned to a value with a low frequency of occurrence. can

Among the prediction methods, the inter prediction method predicts the pixel value of the current picture with reference to information on other pictures, and the intra prediction method uses the correlation between pixels within the same picture to predict the pixel value. Predict pixel values. That is, when intra prediction is performed, the inter prediction mode of the current block is determined using pixel values spatially adjacent to the current block to be encoded, rather than referring to a reference picture to encode the current block. can be performed.

Meanwhile, as the demand for high-resolution images increases, the demand for stereoscopic image contents as a new image service is also increasing. A video compression technique for effectively providing high-resolution and ultra-high-resolution stereoscopic image content is being discussed.

The problem to be solved by the present invention is to provide a method for constructing a list of most probable intra prediction modes (MPM) for intra prediction to increase video encoding and decoding efficiency, and a video signal encoding and decoding apparatus for performing the same. will provide

Another object to be solved by the present invention is to provide a method and apparatus for encoding and decoding a video signal using filters in various ways in order to improve coding efficiency of an image.

Another object of the present invention is to provide a method and apparatus for encoding and decoding a video signal for encoding or decoding a high-resolution image.

According to an embodiment of the present invention, there is provided a method for decoding a video signal, comprising: determining a shape of a current block; determining any one or more of positions and numbers of neighboring blocks that obtain the most probable intra prediction mode of the current block according to the determined shape; and constructing a list of most probable intra prediction modes of the current block based on the determined intra prediction modes of the neighboring blocks, wherein the neighboring blocks include left neighboring blocks and upper neighboring blocks.

The determining may be determined by comparing a horizontal length and a vertical length of the current block.

In an embodiment, the determining may include determining based on at least one of division information, direction information, and pixel information of the current block.

Also, when the horizontal length of the current block is longer than the vertical length, the number of the upper neighboring blocks is determined as the neighboring blocks more than the number of the left neighboring blocks, and the vertical length of the current block is longer than the horizontal length , the number of the left neighboring blocks may be more determined as the neighboring blocks than the number of the upper neighboring blocks.

In an embodiment, the method may further include a smoothing step of applying at least two filters to the determined neighboring blocks. The at least two filters may be determined in consideration of at least one of a size, a shape, a prediction method of the current block, and positions of the neighboring blocks. In an embodiment, different filters among the at least two filters may be applied to the left neighboring blocks and the upper neighboring blocks, respectively.

In another embodiment, a method of decoding a video signal includes: determining shapes of neighboring blocks of a current block; determining a scan order of neighboring blocks for obtaining the most probable intra prediction mode of the current block according to the determined shape; and constructing a list of most probable intra prediction modes of the current block from the neighboring blocks according to the determined order, wherein the neighboring blocks may include left neighboring blocks and upper neighboring blocks.

The determining may be based on sizes of the left neighboring blocks and the upper neighboring blocks.

In an embodiment, the determining of the scan order includes, when the size of the left neighboring blocks is larger than the size of the upper neighboring blocks, scan the intra prediction modes of the left neighboring blocks first and then the most probable within the picture. included in the prediction mode list, and when the size of the upper neighboring blocks is larger than the size of the left neighboring blocks, the intra prediction modes of the upper neighboring blocks are scanned first and included in the most probable intra prediction mode list have. Also, the neighboring blocks may be blocks determined as an intra prediction mode.

In an embodiment, the method may further include a smoothing step of applying at least two filters to the determined neighboring blocks. The at least two filters may be determined in consideration of at least one of a size, a shape, a prediction method of the current block, and positions of the neighboring blocks. In an embodiment, different filters among the at least two filters may be applied to the left neighboring blocks and the upper neighboring blocks, respectively.

In another embodiment, a method of decoding a video signal includes: acquiring a prediction mode of a neighboring block of a current block; determining a scan order of the neighboring blocks for obtaining the most probable intra prediction mode of the current block based on the prediction mode; and constructing a list of most probable intra prediction modes of the current block from the neighboring blocks according to the determined order, wherein the neighboring blocks may include left neighboring blocks and upper neighboring blocks.

determining the scan order. Among the left neighboring blocks and the upper neighboring blocks, blocks obtained by intra prediction may preferentially scan more neighboring blocks.

The obtaining of the prediction mode of the neighboring block may include: dividing a periphery of the current block into sub-blocks; and obtaining prediction modes of the divided sub-blocks.

In an embodiment, the method may further include a smoothing step of applying at least two filters to the determined neighboring blocks. The at least two filters may be determined in consideration of at least one of a size, a shape, a prediction method of the current block, and positions of the neighboring blocks. In an embodiment, different filters among the at least two filters may be applied to the left neighboring blocks and the upper neighboring blocks, respectively.

In another embodiment, a method of decoding a video signal includes: determining a shape of a current block; determining a scan order of neighboring blocks for obtaining the most probable intra prediction mode of the current block according to the determined shape; constructing a list of most probable intra prediction modes of the current block based on intra prediction modes of the neighboring blocks according to the determined scan order, wherein the neighboring blocks are left neighboring blocks and upper neighboring blocks may include

The determining may include a result of comparing the horizontal length of the current block and the vertical length of the current block, and determining based on at least one of division information, direction information, and pixel information of the current block.

In addition, the determining of the scan method may include, when the horizontal length of the current block is longer than the vertical length of the current block, the upper neighboring blocks are scanned before the left neighboring blocks, and the vertical length of the current block is If it is longer than the horizontal length of the current block, it may be determined to scan the left neighboring blocks before the upper neighboring blocks.

In an embodiment, the method may further include a smoothing step of applying at least two filters to the determined neighboring blocks. The at least two filters may be determined in consideration of at least one of a size, a shape, a prediction method of the current block, and positions of the neighboring blocks. In an embodiment, different filters among the at least two filters may be applied to the left neighboring blocks and the upper neighboring blocks, respectively.

In another embodiment, a method of decoding a video signal includes dividing blocks located in the vicinity of a current block into neighboring sub-blocks; and obtaining intra prediction modes of each of the neighboring subblocks, wherein the neighboring subblocks include left neighboring subblocks and upper neighboring subblocks, the neighboring subblocks having a size and The position and number of the neighboring sub-blocks may be determined based on any one or more of the shapes.

The method may further include determining an order of obtaining the most probable intra prediction modes constituting the most probable intra prediction mode list of the current block based on the obtained intra prediction mode.

According to another aspect of the present invention, there is provided an apparatus for decoding a video signal, comprising: a block determiner configured to determine a shape or prediction mode of a current block or neighboring blocks of the current block; an MPM list construction method determining unit for determining at least one of a position, a number, and a scan order of the neighboring blocks for obtaining the most probable intra prediction mode of the current block according to the determined result; and an MPM list constructing unit for configuring the most probable intra prediction mode list of the current block based on the intra prediction modes of the neighboring blocks according to the determined configuration method, wherein the neighboring blocks include left neighboring blocks and It may include upper neighboring blocks.

In an embodiment, a smoothing unit for applying at least two filters to the determined neighboring blocks may be further included. The at least two filters may be determined in consideration of at least one of a size, a shape, a prediction method of the current block, and positions of the neighboring blocks. In an embodiment, different filters among the at least two filters may be applied to the left neighboring blocks and the upper neighboring blocks, respectively.

According to an embodiment of the present invention, any one or more of the positions and the number of neighboring blocks for obtaining the most probable intra prediction mode of the current block is variably determined by determining the shape of the current block, or from the neighboring blocks. By variably determining the scanning order to obtain the most probable intra-prediction mode (MPM), the most probable intra-prediction mode (MPM) is obtained from a neighboring block having a higher correlation with the current block to obtain the current block. It is possible to provide a method and apparatus for encoding or decoding a video signal capable of constructing a list that can be predicted by an efficient encoding method.

In addition, according to another embodiment of the present invention, based on the shape or prediction mode of the neighboring blocks of the current block, by variably determining the scan order of the neighboring blocks for obtaining the most probable intra prediction mode of the current block , encoding or decoding a video signal to improve coding efficiency by allocating the intra prediction mode of the neighboring block having high correlation with the current block to an index mapped with a codeword of a relatively short length of the most probable intra prediction mode list Methods and apparatus can be provided.

In addition, according to another embodiment of the present invention, the prediction block is obtained by obtaining the intra prediction modes of the neighboring sub-blocks from the neighboring sub-blocks located in the vicinity of the current block and constructing a list of the most probable intra prediction modes. It is possible to provide a method and apparatus for encoding or decoding a video signal that can solve the disadvantage that the intra prediction mode of a small number of fixed positions may be different from the intra prediction mode of the current block as the size of .

In addition, embodiments of the present invention provide by adaptively applying at least two filters to the determined neighboring blocks in consideration of at least one or more of the size, shape, prediction method, and position of the neighboring blocks of the current block. , it is possible to improve the coding efficiency of the current block.

1 is a block diagram schematically illustrating a video encoding apparatus according to an embodiment of the present invention.
2 is a block diagram schematically illustrating a video decoding apparatus according to an embodiment of the present invention.
3A and 3B are schematic diagrams for explaining various shapes of a current block according to an embodiment of the present invention.
4A to 5B are schematic diagrams illustrating neighboring blocks for obtaining the most probable intra prediction mode of the current block according to various embodiments of the present invention.
6 and 7 are flowcharts for constructing a list of most probable intra prediction modes according to various embodiments of the present invention.
8 is a schematic diagram for explaining a method of constructing a list of most probable intra prediction modes of a current block according to a shape of a neighboring block according to another embodiment of the present invention.
9 is a flowchart illustrating a method of constructing a list of most probable intra prediction modes according to another embodiment of the present invention.
10 is a schematic diagram for explaining a method of constructing a list of most probable intra prediction modes of a current block according to a shape and a prediction mode of a neighboring block according to another embodiment of the present invention.
11 is a schematic diagram for explaining a method of constructing a list of most probable intra prediction modes of a current block using neighboring sub-blocks according to another embodiment of the present invention.
12 and 13 are schematic diagrams and flowcharts for describing a method of constructing a list of most probable intra prediction modes of a current block according to a shape and a prediction mode of a neighboring block according to an embodiment of the present invention.
14 to 16 are schematic diagrams and flowcharts for explaining a method of constructing a list of most probable intra prediction modes of a current block according to horizontal and vertical lengths of neighboring blocks according to another embodiment of the present invention.
17 and 18 are schematic diagrams and flowcharts for explaining a method of constructing a list of most probable intra prediction modes of a current block by re-segmenting neighboring blocks into sub-blocks according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Examples of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the present invention is as follows It is not limited to an Example. Rather, these examples are provided so that this disclosure will be more thorough and complete, and will fully convey the spirit of the invention to those skilled in the art.

In addition, in the drawings, the thickness or size of each unit is exaggerated for convenience and clarity of description, and the same reference numerals in the drawings refer to the same elements. As used herein, the term “and/or” includes any one and any combination of one or more of those listed items.

The terminology used herein is used to describe specific embodiments, not to limit the present invention. As used herein, the singular form may include the plural form unless the context clearly dictates otherwise. Also, as used herein, "comprise" and/or "comprising" refers to the specified presence of the recited shapes, numbers, steps, actions, members, elements and/or groups thereof. and does not exclude the presence or addition of one or more other shapes, numbers, movements, members, elements and/or groups.

Although the terms first, second, etc. are used herein to describe various components, members, parts, regions, and/or portions, these components, members, parts, regions, and/or portions refer to these terms. It is obvious that it should not be limited by These terms are used only to distinguish one component, member, part, region or part from another region or part. Accordingly, a first component, member, component, region or portion discussed below may refer to a second component, member, component, region or portion without departing from the teachings of the present invention. Also, and/or terms include combinations of a plurality of related recited items or any of a plurality of related recited items.

When a component is referred to as being “connected” or “connected” to another component, it is not only directly connected or connected to the other component, but also between the component and the other component. It should be understood including the case where other components are present. However, when a component is referred to as being “directly connected” or “directly connected” to another component, there is no other component in the middle and the component and the other component are directly connected or connected. should be understood as being

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically illustrating ideal embodiments of the present invention. In the drawings, for example, the size and shape of the members may be exaggerated for convenience and clarity of description, and in actual implementation, variations of the illustrated shape may be expected. Accordingly, embodiments of the present invention should not be construed as limited to the specific shapes of the regions shown herein.

1 is a block diagram schematically illustrating an image encoding apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , the image encoding apparatus 100 includes a picture divider 105 , an inter prediction unit 110 , an intra prediction unit 115 , a transform unit 120 , a quantizer 125 , and a rearrangement unit. 130 , an entropy encoding unit 135 , an inverse quantization unit 140 , an inverse transform unit 145 , a filter unit 150 , and a memory 155 .

Each component shown in FIG. 1 is independently illustrated to represent different characteristic functions in the image encoding apparatus, and does not mean that each component is composed of separate hardware or one software component. That is, each component is included by listing as each component for convenience of description, and at least two components of each component are combined to form one component, or one component is divided into a plurality of components to provide a function can be done An embodiment in which each of these components is integrated or a separate embodiment may be included in the scope of the present invention without departing from the essential aspect of the present invention.

The picture divider 105 may divide the input picture into at least one processing unit. The processing unit may be a prediction unit (hereinafter referred to as 'PU'), a transform unit (hereinafter referred to as 'TU'), or a coding unit (Coding Unit, hereinafter referred to as 'CU'). ) may be However, in the present specification, for convenience of description, a prediction unit may be expressed as a prediction block, a transformation unit may be expressed as a transform block, and a coding or decoding unit may be expressed as a coding block or a decoding block.

In an embodiment, the picture splitter 105 divides one picture into a combination of a plurality of coding units, prediction units, and transformation units, and divides one picture into one picture based on a predetermined criterion (eg, a cost function). A picture may be encoded by selecting a combination of a coding unit, a prediction unit, and a transformation unit.

For example, one picture may be divided into a plurality of coding units. In an embodiment, one picture may divide the coding unit using a recursive tree structure such as a quad tree structure or a binary tree structure, and one image or a largest coding unit (largest coding unit). unit) as a root, a coding unit divided into other coding units may be divided having as many child nodes as the number of divided coding units. A coding unit that is no longer split through this process may become a leaf node. For example, if it is assumed that only square splitting is possible for one coding unit, one coding unit may be split into up to four coding units. However, in the present invention, the coding unit, the prediction unit, and/or the transformation unit are not limited to symmetric partitioning when partitioning, and an asymmetric partition is also possible, and not only four partitions but also two partitions are possible. is merely exemplary, and the present invention is not limited thereto.

A prediction unit may be split in the form of at least one square or rectangle of the same size within one coding unit, and one prediction unit among the split prediction units within one coding unit is a prediction of another. It may be divided to have a shape and size different from the unit.

The prediction unit may include an inter prediction unit 110 performing inter prediction and an intra prediction unit 115 performing intra prediction. In order to increase coding efficiency, an image is predicted using a specific region inside a picture that has already been encoded and decoded, instead of encoding the image signal as it is, and a residual value between the original image and the predicted image is encoded. Also, prediction mode information, motion vector information, etc. used for prediction may be encoded by the entropy encoder 135 together with a residual value and transmitted to the decoder. When a specific encoding mode is used, it is also possible to encode the original block as it is without generating the prediction block through the prediction units 110 and 115 and transmit it to the decoder.

In an embodiment, the prediction units 110 and 115 determine whether inter prediction or intra prediction is to be performed on a prediction unit, and the prediction such as an inter prediction mode, a motion vector, and a reference picture. Specific information according to each method may be determined. In this case, a processing unit in which prediction is performed, a prediction method, and a detailed processing unit may be different. For example, although a prediction mode and a prediction method are determined according to a prediction unit, prediction may be performed according to a transformation unit.

Various picture types or slice types exist according to a prediction method for encoding a coding block. Specifically, there are an I picture (I slice), a P picture (P slice), a B picture (B slice), and the like. An I slice is a slice that is encoded and decoded only by inter prediction, and a P slice is a slice that can be decoded using inter prediction using one motion vector and a reference picture index to predict a sample value of each prediction block. . A B slice is a slice that can be encoded or decoded using inter prediction using one or two motion vectors and indices of reference pictures related to the motion vectors to predict a sample value of each block.

The prediction units 110 and 115 may generate a prediction block including samples predicted by performing prediction on a processing unit of the picture divided by the picture division unit 105 . The picture processing unit in the prediction units 110 and 115 may be a coding unit, a transformation unit, or a prediction unit.

The inter prediction unit 110 may predict a prediction unit based on information on at least one picture of a previous picture or a subsequent picture of the current picture, and in some cases, prediction based on information of a partial region in the current picture that has been encoded units can be predicted. The inter prediction unit 110 may include a reference picture interpolator, a motion prediction unit, and a motion compensator.

In an embodiment, the information on the one or more pictures used for prediction by the inter prediction unit 110 may be information about pictures that have already been encoded and decoded, or information about pictures that have been transformed and stored in an arbitrary method. have. For example, the picture transformed and stored by any of the above methods may be an enlarged or reduced picture of a picture that has been encoded and decoded, or a picture in which the brightness of all pixel values in the picture is changed or the color format is changed. may be

The reference picture interpolator may receive reference picture information from the memory 155 and generate pixel information of integer pixels or less in the reference picture. In the case of a luminance pixel, pixel information of less than an integer may be generated in units of 1/4 pixels by using a DCT-based 8-tap interpolation filter with different filter coefficients. In the case of a color difference signal, pixel information of less than an integer may be generated in units of 1/8 pixel by using a DCT-based interpolation filter that has different filter coefficients. However, the type of filter and the unit for generating pixel information less than an integer are not limited thereto, and a unit for generating pixel information less than or equal to an integer may be determined by using various interpolation filters.

The motion prediction unit may perform motion prediction based on the reference picture interpolated by the reference picture interpolator. Various methods may be used to calculate the motion vector. The motion vector may have a motion vector value in integer pixel units or in 1/2 or 1/4 pixel units based on interpolated pixels. In an embodiment, the motion prediction unit may predict the prediction unit of the current block by using a different motion prediction method. Various methods may be used as the motion prediction method, including a merge method, an advanced motion vector prediction (AMVP) method, and a skip method. As described above, information including the index of the reference picture selected by the inter prediction unit 110, the motion vector predictor (MVP), and the residual signal may be entropy-coded and transmitted to the decoder.

Unlike inter prediction, the intra prediction unit 115 may generate a prediction unit based on reference pixel information around the current block, which is pixel information in the current picture. When the neighboring blocks of the prediction unit are blocks on which inter prediction is performed, that is, when the reference pixel is a pixel on which inter prediction is performed, the reference pixel included in the block on which inter prediction is performed is predicted as the neighboring blocks. It can be used by replacing it with reference pixel information of the block in which ? That is, when the reference pixel is unavailable, the unavailable reference pixel may be replaced with at least one reference pixel among available reference pixels. In an embodiment, the intra prediction unit 115 may use various methods including an intra block copy method.

Also, the intra prediction unit 115 may use the most probable intra prediction mode (MPM) obtained from neighboring blocks to encode the intra prediction mode. According to various embodiments of the present invention, the most probable intra prediction mode list (MPM list) composed of the most probable intra prediction modes may be configured in various ways. To this end, a method of setting the neighboring blocks and a method of scanning them can be variably determined with reference to the current block and neighboring blocks of the current block, and a detailed description thereof will be given later.

Even when the intra prediction unit 115 performs intra prediction, a processing unit in which prediction is performed and a processing unit in which a prediction method and specific content are determined may be different from each other. For example, a prediction mode may be determined as a prediction unit (PU) and prediction may be performed in the prediction unit, or the prediction mode may be determined as a prediction unit, but prediction may be performed in a transform unit (TU).

The prediction mode of intra prediction may include 33 directional prediction modes and at least two non-directional modes. The non-directional mode may include a DC prediction mode and a planar mode. The number of the 35 inter prediction modes is only an example, and the present invention is not limited thereto. In order to make predictions in various ways, intra prediction may be performed in more directional or non-directional modes.

In an embodiment, intra prediction may generate a prediction block after applying a filter to a reference pixel. In this case, whether to apply the filter to the reference pixel may be determined according to the intra prediction mode and/or size of the current block.

A prediction unit (PU) may be determined in various sizes and shapes from a coding unit (CU) that is no longer split. For example, in the case of inter prediction, the prediction unit may have a size such as 2N x 2N, 2N x N, N x 2N, or N x N. In the case of intra prediction, the prediction unit may have a size such as 2N x 2N or N x N (N is an integer). In this case, the N x N prediction unit may be set to be applied only in a specific case. In addition to the above-mentioned size of the prediction unit, an intra prediction unit having a size such as N x mN, mN x N, 2N x mN, or mN x 2N (m is a fraction or an integer) may be further defined and used.

A residual value (a residual block or a residual signal) between the prediction block and the original block generated by the intra prediction unit 115 may be input to the transform unit 120 . Also, prediction mode information, interpolation filter information, etc. used for prediction may be encoded by the entropy encoder 135 together with a residual value and transmitted to a decoder.

Also, in general, in intra prediction, the neighboring blocks of the current block are smoothed using one filter regardless of the positions of the neighboring blocks of the current block. However, according to an embodiment of the present invention, the intra prediction unit 115 may use at least two or more smoothing filters to smooth neighboring blocks of the current block. Such a smoothing method will be described below with reference to FIGS. 3A to 18 .

The transform unit 120 converts the original block as a transform unit and the residual block including residual value information of the prediction unit generated through the prediction units 110 and 115 to DCT (Discrete Cosine Transform), DST (Discrete Sine Transform) , can be transformed using a transformation method such as Karhunen Loeve Transform (KLT). Whether to apply DCT, DST, or KLT to transform the residual block may be determined based on intra prediction mode information of a prediction unit used to generate the residual block.

A transform unit in the transform unit 120 may be a TU, and may have a quad tree structure. In an embodiment, the size of the transformation unit may be determined within a range of a predetermined maximum and minimum size.

The quantizer 125 may quantize the residual values transformed by the transform unit 120 to generate a quantization coefficient. In an embodiment, the transformed residual values may be values transformed into a frequency domain. The quantization coefficient may be changed according to the transform unit or the importance of the image, and the value calculated by the quantization unit 125 may be provided to the inverse quantization unit 140 and the rearrangement unit 130 .

The reordering unit 130 may rearrange the quantization coefficients provided from the quantization unit 125 . The reordering unit 130 may improve encoding efficiency in the entropy encoding unit 135 by rearranging the quantization coefficients. The reordering unit 130 may rearrange the quantized coefficients in the form of a two-dimensional block into a form of a one-dimensional vector through a coefficient scanning method. As for the coefficient scanning method, it may be determined which scanning method is used according to the size of the transform unit and the intra prediction mode. The coefficient scanning method may include a zig-zag scan, a vertical scan for scanning two-dimensional block-shaped coefficients in a column direction, and a horizontal scan for scanning two-dimensional block-shaped coefficients in a row direction. In an embodiment, the reordering unit 130 may increase the entropy encoding efficiency of the entropy encoding unit 135 by changing the order of coefficient scanning based on probabilistic statistics of coefficients transmitted from the quantization unit.

The entropy encoding unit 135 may perform entropy encoding on the quantized coefficients rearranged by the reordering unit 130 . For entropy encoding, various encoding methods such as Exponential Golomb, Context-Adaptive Variable Length Coding (CAVLC), and Content-Adaptive Binary Arithmetic Coding (CABAC) may be used.

The entropy encoding unit 135 includes quantization coefficient information and block type information, prediction mode information, division unit information, prediction unit information and transmission unit information of the coding unit received from the reordering unit 130 and the prediction units 110 and 115, Various information such as motion vector information, reference picture information, block interpolation information, and filtering information may be encoded. Also, according to an embodiment, the entropy encoder 135 may apply a certain change to a transmitted parameter set or syntax, if necessary.

The inverse quantizer 140 inverse quantizes the values quantized by the quantizer 125 , and the inverse transform unit 145 inversely transforms the values inverse quantized in the inverse quantizer 140 . The residual values generated by the inverse quantizer 140 and the inverse transform unit 145 may be combined with the prediction blocks predicted by the predictors 110 and 115 to generate a reconstructed block. The image composed of the generated reconstructed blocks may be a motion compensated image or an MC image (Motion Compensated Picture).

The motion compensation image may be input to the filter unit 150 . The filter unit 150 may include a deblocking filter unit, an offset correction unit (Sample Adaptive Offset, SAO), and an adaptive loop filter unit (ALF). In summary, the motion compensation image is deblocking After the deblocking filter is applied in the filter unit to reduce or remove blocking artifacts, it may be input to the offset correcting unit to correct the offset. The picture output from the offset correction unit may be input to the adaptive loop filter unit and pass through an adaptive loop filter (ALF) filter, and the picture passing through the filter may be transmitted to the memory 155 .

In detail with respect to the filter unit 150 , the deblocking filter unit may remove distortion within a block generated at a boundary between blocks in a reconstructed picture. In order to determine whether to perform deblocking, it may be determined whether to apply a deblocking filter to the current block based on pixels included in several columns or rows included in the block. When a deblocking filter is applied to a block, a strong filter or a weak filter may be applied according to the required deblocking filtering strength. In addition, in applying the deblocking filter, horizontal filtering and vertical filtering may be concurrently processed when performing vertical filtering and horizontal filtering.

The offset correcting unit may correct an offset from the original image in units of pixels with respect to the residual block to which the deblocking filter is applied. In order to correct the offset for a specific picture, a method of dividing pixels included in an image into a certain number of regions, determining a region to be offset, and applying the offset to the region (Band Offset) or the edge of each pixel It may be applied in the form of a method of applying an offset in consideration of information (Edge Offset). However, in an embodiment, the filter unit 150 may not apply filtering to the reconstructed block used for inter prediction.

The adaptive loop filter (ALF) may be performed only when high efficiency is applied based on a value obtained by comparing the filtered reconstructed image and the original image. After dividing pixels included in an image into a predetermined group, one filter to be applied to the corresponding group may be determined and filtering may be performed differentially for each group. As for the information related to whether to apply the ALF, the luminance signal may be transmitted for each coding unit (CU), and the shape and filter coefficients of the ALF filter to be applied may vary according to each block. In addition, the ALF filter of the same type (fixed type) may be applied regardless of the characteristics of the application block.

The memory 155 may store the reconstructed block or picture calculated through the filter unit 150 . The reconstructed block or picture stored in the memory 155 may be provided to the inter prediction unit 110 or the intra prediction unit 115 that performs inter prediction. The pixel values of the reconstructed blocks used in the intra prediction unit 115 may be data to which the deblocking filter unit, the offset corrector, and the adaptive loop filter unit are not applied.

2 is a block diagram schematically illustrating an image decoding apparatus according to an embodiment of the present invention. Referring to FIG. 2 , the image decoding apparatus 200 includes an entropy decoding unit 210, a reordering unit 215, an inverse quantization unit 220, an inverse transform unit 225, an inter prediction unit 230, and intra prediction. It includes a unit 235 , a filter unit 240 , and a memory 245 .

When an image bitstream is input from the image encoding apparatus, the input bitstream may be decoded by a reverse process of a procedure of processing image information in the encoding apparatus. For example, when variable length coding (VLC, hereinafter referred to as 'VLC') such as CAVLC is used to perform entropy encoding in the image encoding apparatus, the entropy decoding unit 210 also performs the entropy encoding in the encoding apparatus. Entropy decoding can be performed by implementing the same VLC table as the used VLC table. In addition, when CABAC is used to perform entropy encoding in the encoding apparatus, the entropy decoding unit 210 may perform entropy decoding using CABAC in response thereto.

The entropy decoding unit 210 provides information for generating a prediction block among the decoded information to the inter prediction unit 230 and the intra prediction unit 235, and the entropy decoding unit performs entropy decoding on the residual value. may be input to the rearrangement unit 215 .

The reordering unit 215 may rearrange the entropy-decoded bitstream by the entropy decoding unit 210 based on a method in which the image encoder rearranges the bitstream. The re-regulation unit 215 may receive information related to coefficient scanning performed by the encoding apparatus and perform rearrangement through a method of scanning inversely based on the scanning order performed by the encoding apparatus.

The inverse quantization unit 220 may perform inverse quantization based on the quantization parameter provided by the encoding apparatus and the reordered coefficient values of the blocks. The inverse transform unit 225 may perform inverse DCT, inverse DST, or inverse KLT on the DCT, DST, or KLT performed by the transform unit of the encoding apparatus on the quantization result performed by the image encoding apparatus. The inverse transformation may be performed based on a transmission unit determined by the encoding apparatus or a division unit of an image. The transform unit of the encoding device may selectively perform DCT, DST, or KLT according to information such as a prediction method, a size of a current block, and a prediction direction, and the inverse transform unit 225 of the decoding device is configured in the transform unit of the encoding device. An inverse transformation method may be determined based on the performed transformation information to perform the inverse transformation.

The prediction units 230 and 235 may generate a prediction block based on information related to generation of a prediction block provided from the entropy decoding unit 210 and previously decoded block and/or picture information provided from the memory 245 . The reconstructed block may be generated using the prediction block generated by the prediction units 230 and 235 and the residual block provided by the inverse transform unit 225 . The specific prediction method performed by the prediction units 230 and 235 may be the same as the prediction method performed by the prediction units 110 and 115 of the encoding apparatus.

The prediction units 230 and 235 may include a prediction unit determiner (not shown), an inter prediction unit 230 , and an intra prediction unit 235 . The prediction unit determining unit receives various information such as prediction unit information input from the entropy decoder 210, prediction mode information of the intra prediction method, and motion prediction related information of the inter prediction method, and receives a prediction unit in the current coding unit. , and it is possible to determine whether the prediction unit performs inter prediction or intra prediction.

The inter prediction unit 230 uses information required for inter prediction of the current prediction unit provided from the image encoder, and based on information included in at least one of a picture before or after the current picture including the current prediction unit. can perform inter-screen prediction for the current prediction unit.

Specifically, in inter prediction, a prediction block for the current block may be generated by selecting a reference picture for the current block and selecting a reference block having the same size as the current block. In this case, in order to use the information of the reference picture, information on neighboring blocks of the current picture may be used. For example, a prediction block for the current block may be generated based on information on the neighboring block using methods such as a skip mode, a merge mode, and advanced motion vector prediction (AMVP).

The prediction block may be generated in units of samples equal to or less than an integer, such as 1/2 pixel sample unit and 1/4 pixel sample unit. In this case, the motion vector may also be expressed in units of integer pixels or less. For example, the luminance pixel may be expressed in units of 1/4 pixels and the chrominance pixels may be expressed in units of 1/8 pixels.

Motion information including a motion vector and a reference picture index required for inter prediction of the current block may be derived by checking a skip flag, a merge flag, etc. received from the encoding apparatus, and corresponding thereto.

The intra prediction unit 235 may generate a prediction block based on pixel information in the current picture. When the prediction unit is a prediction unit on which intra prediction is performed, intra prediction may be performed based on intra prediction mode information of the prediction unit provided by the image encoder. In an embodiment, the intra prediction unit 235 may use various methods including an intra block copy method.

The intra prediction unit 235 may use the most probable intra prediction mode (MPM) obtained from neighboring blocks to encode the intra prediction mode. In an embodiment, the most probable intra prediction mode may use an intra prediction mode of a spatial neighboring block of the current block.

For example, first, spatially, the intra prediction blocks of the left and upper neighboring blocks of the current block are compared, and if the two intra prediction modes are different, the intra prediction mode of the left neighboring block is selected as the first most probable intra prediction mode index. and assigns the intra prediction mode of the upper neighboring block to the second most probable intra prediction mode index. When the intra prediction modes of the upper neighboring block and the left neighboring block are neither the planar nor the DC mode, the planar or DC mode may be assigned to the third most probable intra prediction mode index.

If the intra prediction modes of the upper neighboring block and the left neighboring block are the same, it is determined whether the intra prediction mode of the left neighboring block is the planar or DC mode, and in the case of the planar or DC mode, the first most probable picture Plana may be assigned to my prediction mode index, and DC mode may be assigned to the second most probable intra prediction mode index. Thereafter, a vertical mode may be assigned to the third most probable intra prediction mode index. If the intra prediction mode of the left neighboring block is a directional mode other than the planar or DC mode, the three most probable intra prediction mode indexes are the intra prediction mode of the left neighboring block and the vicinity of the intra prediction mode. Mode (±1) may be assigned to the index of the most probable intra prediction mode list.

However, in order to predict the current block more similarly to the original block, it is necessary to use more probable intra prediction modes to determine the intra prediction mode of the current block. Therefore, in addition to the above method, the following method may be used to construct the list of most probable intra prediction modes of the current block.

In one embodiment, the six most probable intra prediction modes may be used to encode the intra prediction mode of the current block. The neighboring blocks used for obtaining the most probable intra prediction mode may be a left upper block, an upper block, an upper right block, a left block, and a left lower block of the current block.

For example, the five neighboring blocks may be scanned and the intra prediction modes of the neighboring blocks may be allocated to the most probable intra prediction mode list. In this case, planar mode and DC mode in addition to the intra prediction mode from the five neighboring blocks may be allocated to the most probable intra prediction mode list. In addition, the most likely overlapping intra prediction mode is not repeatedly assigned to the list.

If the number of intra-prediction modes in the initial most probable intra-prediction mode list set as above is not six, the directional intra-prediction mode among the intra-prediction modes included in the initial most probable intra prediction mode list. Ambient (±1) mode is included in the list of most probable intra prediction modes. Nevertheless, if there are not six intra prediction modes in the list, the vertical intra prediction mode, the horizontal intra prediction mode, the first diagonal intra prediction mode (2), the second It can be completed by being included in the list of the most probable intra prediction modes in the order of the two diagonal intra prediction modes 34 .

In the method of setting the most probable intra prediction mode list, the number and positions of neighboring blocks for obtaining the most probable intra prediction mode, and a method of scanning the neighboring blocks are preset. However, in order to predict the current block to be more similar to the original block, it is necessary to obtain the most probable intra prediction mode from the neighboring block in various ways.

In particular, when the current block is a non-square block rather than a square block, neighboring blocks with relatively high correlation may exist among neighboring blocks located around the current block. If the intra prediction mode of the current block is obtained by using such highly correlated neighboring blocks, it is possible to not only increase coding efficiency but also obtain a current block more similar to the original image. The non-square block may include blocks having various vertical and horizontal ratios, such as N*mN (where m is a fraction and an integer), rather than a block having the same horizontal length and vertical length. A method of configuring a neighboring block related thereto and a method of configuring a list of most probable intra prediction modes will be described later with reference to FIGS. 3A to 18 .

In an embodiment, a processing unit in which prediction is performed by the intra prediction unit 235 and a processing unit in which a prediction method and specific content are determined may be different from each other. For example, a prediction mode may be determined in a prediction unit and prediction may be performed in a prediction unit, or a prediction mode may be determined in a prediction unit and intra prediction may be performed in a transformation unit.

The intra prediction unit 235 may include an Adaptive Intra Smoothing (AIS) filter unit, a reference pixel interpolator unit, and a DC filter unit. The AIS filter unit is a part that performs filtering on the reference pixel of the current block, and may determine whether to apply the filter according to the prediction mode of the current prediction unit and apply the filter. AIS filtering may be performed on the reference pixel of the current block by using the prediction mode and AIS filter information of the prediction unit provided by the image encoder. When the prediction mode of the current block is a mode in which AIS filtering is not performed, the AIS filter unit may not be applied to the current block.

When the prediction mode of the prediction unit is a prediction unit that performs intra prediction based on the pixel value obtained by interpolating the reference pixel, the reference pixel interpolator interpolates the reference pixel to generate the reference pixel of a pixel unit having an integer value or less. have. When the prediction mode of the current prediction unit is a prediction mode that generates a prediction block without interpolating the reference pixel, the reference pixel may not be interpolated. When the prediction mode of the current block is the DC mode, the DC filter unit may generate the prediction block through filtering.

Also, in general, in intra prediction, the neighboring blocks of the current block are smoothed using one filter regardless of the positions of the neighboring blocks of the current block. However, according to an embodiment of the present invention, the intra prediction unit 235 may use at least two or more smoothing filters to smooth neighboring blocks of the current block. Such a smoothing method will be described below with reference to FIGS. 3A to 18 .

The reconstructed block and/or picture may be provided to the filter unit 240 . The filter unit 240 may include a deblocking filter unit, an offset correction unit (Sample Adaptive Offset), and/or an adaptive loop filter unit in the reconstructed block and/or picture. The deblocking filter unit may receive information indicating whether a deblocking filter is applied to a corresponding block or picture from an image encoder and information indicating whether a strong filter or a weak filter is applied when the deblocking filter is applied. The deblocking filter unit may receive the deblocking filter related information provided from the image encoder, and perform deblocking filtering on the corresponding block in the image decoder.

The offset correction unit may perform offset correction on the reconstructed image based on the type of offset correction applied to the image during encoding and information on the offset value. The adaptive loop filter unit may be applied as a coding unit based on information such as information on whether the adaptive loop filter is applied and information on coefficients of the adaptive loop filter provided from the encoder. Information related to the adaptive loop filter may be provided in a specific parameter set.

The memory 245 may store the reconstructed picture or block to be later used as a reference picture or reference block, and may also provide the reconstructed picture to an output unit.

Although omitted herein for convenience of description, the bitstream input to the decoding apparatus may be input to the entropy decoding unit through a parsing step. Also, the entropy decoding unit may perform a parsing process.

In the present specification, coding may be interpreted as encoding or decoding in some cases, and information includes all values, parameters, coefficients, elements, flags, and the like. can be understood as doing 'Screen' or 'picture' generally means a unit representing a single image in a specific time period, and 'slice' and 'frame' are It is a unit constituting a part, and may be used interchangeably with a picture, if necessary.

A 'pixel', 'pixel' or 'pel' represents the smallest unit constituting one image. In addition, as a term indicating a value of a specific pixel, a 'sample' may be used. A sample may be divided into a luminance (Luma) and a chroma (Chroma) component, but in general, a term including both of them may be used. In the above, the color difference component represents a difference between predetermined colors and is generally composed of Cb and Cr.

A 'unit' refers to a basic unit of image processing or a specific position of an image, such as the above-described coding unit, prediction unit, and transformation unit, and in some cases, terms such as 'block' or 'area' and may be used interchangeably. Also, a block may be used as a term indicating a set of samples or transform coefficients composed of M columns and N rows.

3A and 3B are schematic diagrams for explaining various shapes of a current block according to an embodiment of the present invention.

Referring to FIGS. 3A and 3B , the current block may be blocks 301 and 302 having various shapes as well as a square shape. For example, as shown in FIG. 3A , the horizontal length (a) of the current block may be longer than the vertical length (b) of the current block (a > b), and as shown in FIG. 3B , the current block It may have a rectangular shape (a<b) in which the vertical length (b) of the current block is longer than the horizontal length (a) of the current block. In an embodiment, the shape of the current blocks 301 and 302 may be determined by comparing the horizontal length and the vertical length of the current block, and in detail, the direction of the current blocks 301 and 302 may be determined. have.

As shown in FIG. 3A , when the horizontal length of the current block 301 is a rectangular block longer than the vertical length, that is, the horizontal current block 301 is located on the left side of the current block 301 . A correlation may be higher with a neighboring block located above the current block 301 (hereinafter referred to as an upper neighboring block) than a located neighboring block (hereinafter referred to as a left neighboring block). In addition, in the case of the current block 302 in the vertical direction as shown in FIG. 3B , the correlation between the left neighboring block and the current block 302 may be higher than that of the upper neighboring block of the current block 302 . In this case, in order to obtain the most probable intra prediction mode of the current blocks 301 and 302 , it is necessary to refer to neighboring blocks with higher correlations relatively many to accurately determine the intra prediction mode of the current blocks 301 and 302 . It can help you decide.

That is, in the case of the current block 301 in the horizontal direction, more upper neighboring blocks are referred to, and in the case of the current block 302 in the vertical direction, the left neighboring blocks are more referenced, and the most of the current blocks 301 and 302 are It is desirable to obtain possible inter prediction modes. In the present invention, the direction of the current blocks 301 and 302 is determined by comparing the horizontal and vertical lengths of the current blocks 301 and 302, but the present invention is not limited thereto, and the direction of the current blocks 301 and 302 is determined in various ways. can do. For example, the shape or direction of the current blocks 301 and 302 is based on any one or more of segmentation information, direction information, and pixel information of the current blocks 301 and 302 received from an encoder or previously obtained at a decoder. can be judged.

The number or positions of neighboring blocks for constituting the most probable intra prediction mode list of the current blocks 301 and 302 determined by the above method may be variably determined according to the shape or direction of the current blocks 301 and 302. . In detail, depending on the shape of the current blocks 301 and 302 , the number of upper neighboring blocks or left neighboring blocks referred to for constructing the most probable intra prediction mode list may be determined differently. For example, in the current block 301 in the horizontal direction, the number of upper neighboring blocks considered to construct the most probable intra prediction mode list may be greater than the number of left neighboring blocks. Meanwhile, the current block 302 in the vertical direction may construct the most probable intra prediction mode list in consideration of a larger number of left neighboring blocks than the upper neighboring blocks.

Also, depending on the shape of the current blocks 301 and 302, positions of the upper neighboring blocks or the left neighboring blocks referred to for constructing the most probable intra prediction mode list may be determined differently. For example, in the current block 301 in the horizontal direction, the position of the upper neighboring block considered to construct the most probable intra prediction mode list may be considered to be different from the position of the left neighboring block. Meanwhile, the current block 302 in the vertical direction may consider the position of the left neighboring block to be considered to construct the most probable intra prediction mode list to be different from the position of the upper neighboring block.

4A to 5B are schematic diagrams illustrating neighboring blocks considered to construct a list of most probable intra prediction modes of a current block according to various embodiments of the present invention, and FIGS. 6 and 7 are various embodiments of the present invention; It is a flowchart for constructing a list of the most probable intra prediction modes of the current block according to

Referring to FIGS. 6 and 7 along with FIGS. 4A and 4B , the shape of the current block may be first determined (S60), and the location and/or the number of neighboring blocks may be determined based on the result of the determination (S61). . For example, the shape or direction of the current block may be determined by comparing the horizontal length of the current block and the vertical length of the current block (S71). For example, when the current block 401 is a block in the horizontal direction ( S72 ), since the horizontal length (a) of the current block is greater than the vertical length (b), the number of upper neighboring blocks considered as neighboring blocks is the left There may be more than the number of neighboring blocks (S72). For example, blocks at positions L0 and L1 may be considered for left neighboring blocks, and blocks at positions A0, A1, A2, and A3 may be considered for upper neighboring blocks.

In addition, when the current block 402 is a block in the vertical direction (S73), since the vertical length b of the current block is greater than the horizontal length a, the neighbor considered for constructing the most probable intra prediction mode list As blocks, more left neighboring blocks than upper neighboring blocks may be considered (S73). For example, among the neighboring blocks, only blocks at positions A0 and A1 may be considered as upper neighboring blocks, and blocks at positions L0, L1, L2, and L3 may be considered as left neighboring blocks. Thereafter, the most probable intra prediction mode list may be constructed by obtaining the most probable intra prediction mode (MPM) of the current block from the determined neighboring blocks including the upper neighboring blocks and the left neighboring blocks (S62, S74).

In this way, by determining the shape of the current block and determining the position and number of neighboring blocks to be considered for constructing the most probable intra prediction mode list of the current block based on the determination of the shape of the current block, a neighbor having a higher correlation with the current block By obtaining the most probable intra prediction mode (MPM) from the blocks, the current block can be efficiently predicted within the picture.

In addition, the intra prediction encoding of the current block may further include smoothing by applying a smoothing filter to neighboring blocks of the current block. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks of the current block.

In an embodiment, the neighboring blocks may include left neighboring blocks and upper neighboring blocks, and the smoothing filter may apply a different filter to each of the left neighboring blocks and the upper neighboring blocks. For example, when the current block has a rectangular shape, the A intra smoothing filter may be used for the left neighboring blocks, and the B intra smoothing filter may be applied to the upper neighboring blocks. In this way, the at least two filters may be applied according to spatial positions of the neighboring blocks.

In an embodiment, the intra smoothing filter may be determined according to a size or shape of a current block for which the intra prediction is performed. For example, when the current block has a rectangular shape, the A intra-smoothing filter is applied to a neighboring block in the longest direction among the horizontal or vertical sides of the current block, and the B intra-smoothing filter is applied to the horizontal direction of the current block. Alternatively, it may be applied to a neighboring block in a direction having a shorter length among vertical sides. In this case, the A intra smoothing filter may be a smoothing filter that tends to compress a signal more than the B intra smoothing filter. Also, the information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one of a size, a shape, and a prediction mode for predicting the current block. In consideration of the above, the decoding apparatus may select a plurality of candidate filters.

Referring to FIGS. 5A and 5B , positions of neighboring blocks considered for constructing the most probable intra prediction mode list may be differently determined based on the shape of the current block. As shown in FIG. 5A , when the current block 501 is in the horizontal direction, the left neighboring blocks use the two lower left positions (L, BL) of the current block 501, and the upper neighboring blocks use the upper middle position ( A) and blocks in the upper right position (AR) can be used to construct the most probable intra prediction mode list. In addition, as shown in FIG. 5B , when the current block 502 is in the vertical direction, upper neighboring blocks (A, AR) at two upper and right positions are used, and the left middle position (L) and the left lower position ( BL) blocks can be used. However, the number and positions of neighboring blocks considered to construct the most probable intra prediction mode list are not limited to the above-described embodiments, and may be determined in various ways.

In addition, the intra prediction encoding of the current block may further include smoothing by applying a smoothing filter to neighboring blocks of the current block. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks of the current block.

In an embodiment, the neighboring blocks may include left neighboring blocks and upper neighboring blocks, and the smoothing filter may apply a different filter to each of the left neighboring blocks and the upper neighboring blocks. For example, when the current block has a rectangular shape, the A intra smoothing filter may be used for the left neighboring blocks, and the B intra smoothing filter may be applied to the upper neighboring blocks. In this way, the at least two filters may be applied according to spatial positions of the neighboring blocks.

In an embodiment, the intra smoothing filter may be determined according to a size or shape of a current block for which the intra prediction is performed. For example, when the current block has a rectangular shape, the A intra-smoothing filter is applied to a neighboring block in the longest direction among the horizontal or vertical sides of the current block, and the B intra-smoothing filter is applied to the horizontal direction of the current block. Alternatively, it may be applied to a neighboring block in a direction having a shorter length among vertical sides. In this case, the A intra smoothing filter may be a smoothing filter that tends to compress a signal more than the B intra smoothing filter. In addition, the information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one of a size, a shape, and a prediction mode for predicting the current block In consideration of the above, the decoding apparatus may select a plurality of candidate filters.

8 is a schematic diagram for explaining a method of constructing a list of most probable intra prediction modes of a current block according to the shape of a neighboring block according to another embodiment of the present invention, and FIG. 9 is the most probable screen described with reference to FIG. 8 It is a flowchart for explaining a method of configuring my prediction mode list.

Referring to FIG. 8 , neighboring blocks positioned around the current block 801 may have various sizes. The current block 801 may have a high correlation with neighboring blocks having a relatively large size among the neighboring blocks 802, 803, 804, ..., 807 encoded in the intra prediction mode. For example, when the size of the upper neighboring blocks 806 and 807 is larger than the size of the upper neighboring blocks 802, 803, 804, and 805 of the current block 801, the current block 801 is the upper neighboring blocks 806, 807. ) will be highly correlated. In this case, when the most probable intra prediction mode list is constructed by the conventional method, the intra prediction modes of the upper neighboring blocks 806 and 807 are assigned to the largest index of the most probable intra prediction mode list of the current block. Therefore, coding efficiency may be reduced.

Therefore, the present invention can provide a scanning method of neighboring blocks capable of allocating the intra prediction mode of the neighboring block with high correlation according to the size of the neighboring blocks of the current block to the low index of the most probable intra prediction mode list. have. In order to provide a method for scanning the neighboring blocks, in an embodiment, shapes of neighboring blocks of the current block are first determined ( S91 ). In detail, size configurations of neighboring blocks may be distinguished according to prediction modes and sizes of coding blocks at BL, L, A, AR, and AL positions.

In an embodiment, the scanning method (order) of the neighboring blocks may be determined according to the shape or size of the neighboring blocks ( S92 ). For example, the size of the current block 801 and the neighboring blocks 806 and 807 in which A and AR are located is 16 x 16, and the size of the neighboring blocks 804 and 805 in which L and BL are located is 8. In the case of x 8, the most probable intra prediction mode list is constructed by scanning the neighboring blocks 806 and 807 in which A and AR are located before the neighboring blocks 804 and 805 in which L and BL are located (S93). ), it is possible to increase the coding efficiency by assigning the intra prediction mode with high correlation to a small index.

In another example, from among the neighboring blocks 802, 803, 804, ..., 807 encoded in the intra prediction mode including the left neighboring blocks and the upper neighboring blocks, a neighboring block having a relatively large size is scanned and the most By constructing a list of possible intra prediction modes ( S93 ), it is possible to increase coding efficiency by allocating intra prediction modes with high correlation to small indexes. The current block 801 of FIG. 8 may scan neighboring blocks in the order of A->AR->L->BL->AL to construct the most probable intra prediction mode list. In this case, the type and order of modes additionally considered in the intra prediction mode scan order of spatial neighboring blocks such as vertical mode and planar mode are not limited and may be used. In addition, in the present invention, the positions of the neighboring blocks are not limited to the L, BL, A, AR, and AL positions mentioned, and the positions of neighboring blocks considered according to the shape of the current block are not limited to the upper side and the left side, and all available positions are not limited. location can be considered.

As another example, if the order of scanning neighboring blocks is determined based on other criteria, the mapping relationship between the index of the most probable intra prediction mode list and the intra prediction modes is determined according to the shape or size of the neighboring blocks. can be changed The first most probable intra-prediction mode in the list of most probable intra-prediction modes using the scan order determined based on other criteria is the intra-prediction mode of the neighboring block 804 at position L and the second most probable The intra prediction mode exemplifies the case of the intra prediction mode of the neighboring block 806 at position A. In this case, since the size of the neighboring block 806 at the A position is larger than the neighboring block 804 at the L position, the correlation is considered to be higher, and the second most probable intra prediction mode is the first most probable intra prediction mode. The prediction mode is changed to the intra prediction mode of the neighboring block 806 at position A, and the second most probable intra prediction mode is within the picture of the neighboring block 804 at position L which is the first most probable intra prediction mode. You can change to predictive mode. Here, the scan order determined based on different criteria may involve always using the same scan order, or may involve some other criteria.

In addition, the intra prediction encoding of the current block may further include applying a smoothing filter to neighboring blocks of the current block to perform smoothing. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks 802, ..., 807 of the current block.

In one embodiment, the neighboring blocks may include left neighboring blocks 802, ..., 805 and upper neighboring blocks 806, 807, and the smoothing filter may include the left neighboring blocks 802, ..., 805) and a different filter may be used for each of the upper neighboring blocks 806 and 807. For example, when the current block has a rectangular shape, the A intra smoothing filter may be used for the left neighboring blocks 802 , ... , 805 , and the B intra smoothing filter may be used for the upper neighboring blocks 806 , 807 . can be applied. In this way, the at least two filters may be applied according to spatial positions of the neighboring blocks.

In an embodiment, the intra smoothing filter may be determined according to a size or shape of a current block for which the intra prediction is performed. For example, when the current block has a rectangular shape, the A intra-smoothing filter is applied to a neighboring block in the longest direction among the horizontal or vertical sides of the current block, and the B intra-smoothing filter is applied to the horizontal direction of the current block. Alternatively, it may be applied to a neighboring block in a direction having a shorter length among vertical sides. In this case, the A intra smoothing filter may be a smoothing filter that tends to compress a signal more than the B intra smoothing filter. In addition, the information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one of a size, a shape, and a prediction mode for predicting the current block In consideration of the above, the decoding apparatus may select a plurality of candidate filters.

10 to 13 are schematic diagrams and flowcharts for explaining a method of constructing a list of most probable intra prediction modes of a current block based on a shape and a prediction mode of a neighboring block according to another embodiment of the present invention.

Referring to FIG. 10 , a method of constructing the most probable intra prediction mode list of the current block 1001 with reference to the neighboring blocks 1002 , ..., 1007 of the current block 1001 is proposed. For example, when the upper neighboring blocks 1004, 1005, 1006, and 1007 of the current block 1001 are coded in the intra prediction mode, and the left neighboring blocks 1002 and 1003 are coded in the inter prediction mode. , the current block 1001 may have a higher correlation with the upper neighboring blocks 1004 , 1005 , 1006 , and 1007 than the left neighboring blocks 1002 and 1003 .

In this case, when the most probable intra prediction mode list is constructed in the conventional way, the intra prediction modes of the upper neighboring blocks 1004, 1005, 1006, and 1007 are allocated to the large indexes of the list, so that the coding efficiency is reduced. will be Therefore, by constructing the most probable intra prediction mode list based on the prediction modes of the neighboring blocks 1002, ..., 1007 of the current block 1001, coding efficiency can be improved.

In order to construct the most probable intra prediction mode list by the above-described method, first, information about shapes and prediction modes of neighboring blocks 1002, ..., 1007 of the current block 1001 is obtained (S130). . The information on the prediction mode of the neighboring blocks may be flag information and prediction mode index indicating the prediction mode of each neighboring block, but is not limited thereto, and any information capable of indicating the prediction mode may be used.

In an embodiment, a scanning method of the neighboring blocks may be determined based on at least one of a shape and a prediction mode of the neighboring blocks ( S131 ). For example, when a scanning method of neighboring blocks is determined according to the prediction modes and sizes of the coding blocks at L and A positions, the neighboring block 1002 at the L position is an inter-picture mode, and the neighboring block 1006 at the A position is In the intra-picture mode, by first scanning the upper neighboring blocks 1005, 1006, and 1007 to construct a list of most probable intra-prediction modes (S132), the intra-prediction mode with high correlation is assigned to a small index for coding efficiency can increase The coding blocks at the L and A positions are only examples, and the positions of the left neighboring block and the upper neighboring block are not limited thereto.

In another embodiment, a scanning method of the neighboring blocks may be determined based on at least one of a shape and a prediction mode of the neighboring blocks ( S131 ). For example, when a scanning method of neighboring blocks is determined according to the prediction mode of the coding block at the BL, L, AL, A, and AR positions and the intra prediction mode frequency of the coding blocks, the upper neighboring blocks 1006, If the prediction mode of 1007 is the intra-picture mode and the prediction mode of the left neighboring blocks 1002 and 1003 is the inter-picture mode, the upper neighboring blocks 1005, 1006, 1007 are first scanned, and the left neighboring blocks 1002, 1002, 1003) will be scanned later. Here, the scan order of the upper neighboring blocks 1005 , 1006 , and 1007 scans first from among the upper neighboring blocks with a larger size, and the scan order of the left neighboring blocks 1002 and 1003 is the left neighboring block Among them, by first scanning a neighboring block of a larger size to construct a list of most probable intra prediction modes ( S132 ), intra prediction modes with high correlation are assigned to small indexes, thereby increasing coding efficiency. The positions of BL, L, AL, A, and AR are only examples, and it will be natural that the positions are not limited thereto.

In addition, the intra prediction encoding of the current block may further include smoothing by applying a smoothing filter to neighboring blocks of the current block. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks of the current block.

In an embodiment, the smoothing filter may be determined differently in consideration of at least one of a prediction mode and a size of the left neighboring blocks and the upper neighboring blocks. Alternatively, it may be determined differently according to spatial positions of the neighboring blocks. In addition, the information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one of a size, a shape, and a prediction mode for predicting the current block In consideration of the above, the decoding apparatus may select a plurality of candidate filters.

In another embodiment, the prediction mode configuration of the neighboring blocks may be determined by dividing all neighboring blocks of the current block 1001 into sub-block units. 11 is a schematic diagram for explaining a method of constructing a list of most probable intra prediction modes of a current block using neighboring sub-blocks according to another embodiment of the present invention.

Referring to FIG. 11 , blocks positioned around the current block 1101 may be divided into sub-block units. The sub-blocks may include a prediction mode configuration determination region 1 formed by dividing upper neighboring blocks and a prediction mode configuration determining region 2 formed by dividing left neighboring blocks. The prediction mode of the neighboring blocks may be determined by comparing the number of intra-picture modes of the sub-blocks included in the prediction mode configuration determination region 1 with the number of intra-picture modes of the sub-blocks included in the prediction mode configuration determination region 2. . For example, if the sub-blocks included in the prediction mode configuration determination region 1 have six intra-picture modes and the sub-blocks included in the prediction mode configuration determination region 2 have four intra-picture modes, the current In the neighboring blocks of the block 1101, it may be determined that the upper neighboring blocks are more coded in the intra-picture mode than the left neighboring blocks.

In an embodiment, the location and size of the prediction mode configuration determination region may be variously changed according to the size and shape of the current block 1101 . The size and position of the sub-blocks may also be variously changed according to the size and shape of the current block 1101 . In addition, the size and position of the sub-blocks and the size and position of the prediction mode configuration determination region are merely examples, and are not limited thereto.

Thereafter, based on the obtained prediction modes of the neighboring blocks, a scanning method of neighboring blocks for constructing a list of the most probable intra prediction modes of the current block 1101 is determined ( S131 ). In detail, in the above step, it may be considered to first scan the neighboring blocks in positions where the neighboring blocks encoded in the intra-mode among the upper neighboring blocks and the left neighboring blocks are many.

Referring to FIG. 12A , the coding blocks 1216 , 1217 , and 1215 at the upper neighboring block position of the current block 1210 are coded in the intra-picture mode, and two blocks 1212 of the coding blocks at the left neighboring block position are coded. It can be seen that 1213 is coded in the inter-picture mode and one block 1211 is coded in the intra-picture mode. In this case, it is determined to scan the upper neighboring blocks 1216 and 1217 first, and then scan the left neighboring blocks 1212 and 1213 to construct the most probable intra prediction mode list of the current block 1210 . can For example, to determine the intra prediction mode order of the spatial neighboring blocks 1211, ..., 1217 for the most probable intra prediction mode list construction as AR->A->AL->L->BL can

Referring to FIG. 12B , two blocks 1225 and 1226 of the coding blocks at the position of the upper neighboring block of the current block 1220 are coded in the inter picture mode, and one block 1227 is coded in the intra prediction mode. , it can be seen that the coding blocks 1224 , 1222 , and 1223 of the left neighboring block are coded in the intra-picture mode. In this case, it is determined to scan the left neighboring blocks 1222 and 1223 first, and then scan the upper neighboring blocks 1226 and 1227 to configure the most probable intra prediction mode list of the current block 1220 . can For example, the scan order of the spatial neighboring blocks 1221 , ..., 1227 for configuring the most probable intra prediction mode list may be determined as BL->L->AL->A->AR. When the scan order is determined with reference to FIGS. 12A and 12B , the types and scan order of intra prediction modes such as planar mode and DC mode that are additionally considered are not limited and may be variously added.

In addition, the intra prediction encoding of the current block may further include performing smoothing by applying a smoothing filter to neighboring blocks of the current block. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks of the current block.

In an embodiment, the neighboring blocks may include left neighboring blocks and upper neighboring blocks, and the smoothing filter may use a different filter for each of the left neighboring blocks and the upper neighboring blocks. For example, when the current block has a rectangular shape, the A intra smoothing filter may be used for the left neighboring blocks, and the B intra smoothing filter may be applied to the upper neighboring blocks. In this way, the at least two filters may be applied according to spatial positions of the neighboring blocks.

In an embodiment, the intra smoothing filter may be determined according to a size or shape of a current block for which the intra prediction is performed. For example, when the current block has a rectangular shape, the A intra-smoothing filter is applied to a neighboring block in the longest direction among the horizontal or vertical sides of the current block, and the B intra-smoothing filter is applied to the horizontal direction of the current block. Alternatively, it may be applied to a neighboring block in a direction having a shorter length among vertical sides. In this case, the A intra smoothing filter may be a smoothing filter that tends to compress a signal more than the B intra smoothing filter.

Also, the smoothing filter may be determined differently in consideration of at least one of a prediction mode and a size of the left neighboring blocks and the upper neighboring blocks. The information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one or more of the size, shape, and prediction mode for predicting the current block In consideration of this, the decoding apparatus may select a plurality of candidate filters.

As described above, in the method and apparatus for decoding a video signal according to an embodiment of the present invention, the neighbor obtains the most probable intra prediction mode of the current block based on the shape or prediction mode of the neighboring blocks of the current block. By variably determining the scan order of the blocks, it is possible to improve coding efficiency by allocating the intra prediction mode of the neighboring block having high correlation with the current block to the low index of the most probable intra prediction mode list.

14 to 16 are schematic diagrams and flowcharts for explaining a method of constructing a list of most probable intra prediction modes of a current block according to horizontal and vertical lengths of neighboring blocks according to another embodiment of the present invention.

14 and 16 , the current block 1410 may be a prediction block having a non-square shape, and an intra prediction mode of neighboring blocks AL, A, and AR located above the current block 1410 . Since the correlation with the current block 1410 is higher than that of the intra prediction modes of neighboring blocks L and BL located on the left, the probability of similarity to the intra prediction mode of the current block 1410 may be high. Therefore, in order to effectively construct a list of the most probable intra prediction modes of the current block 1410, the shape of the current block 1410 must be determined (S160).

Various methods may be used to determine the shape of the current block 1410 . For example, the shape or direction of the current block 1410 may be determined by comparing the horizontal length and the vertical length of the current block 1410 . In one embodiment, the shape or direction of the current block 1410 is determined by comparing the horizontal length and the vertical length of the current block 1410 based on the position value of the start pixel and the position value of the end pixel of the current block 1410 . It may be determined by obtaining information on the horizontal length and vertical length of the current block 1410 , and division information of the current block 1410 or direction information indicating the vertical or horizontal direction of the current block 1410 . It can also be obtained based on A method of determining the shape or direction of the current block 1410 is not limited thereto.

Thereafter, the list is constructed by obtaining intra prediction mode candidates according to the scan order of the neighboring blocks for constructing the determined most probable intra prediction mode list ( S162 ). Referring to FIG. 15A , since the horizontal length of the current block 1510 is longer than the vertical length, it may be determined that upper neighboring blocks are scanned before left neighboring blocks in order to construct the most probable intra prediction mode list. For example, the determined scan order may be AR->A->AL->L->BL to obtain an intra prediction mode of blocks existing at the position to configure a list. In addition, by adding the planar mode and the DC mode between the scan orders of the spatial neighboring blocks, for example, it is possible to scan in the order AR->A->AL->Plana->DC->L->BL. Referring to FIG. 15B , since the vertical length of the current block 1520 is longer than the horizontal length, it may be determined that the left neighboring blocks are scanned before the upper neighboring blocks in order to construct the most probable intra prediction mode list. For example, the determined scan order may be BL->L->AL->A->AR to obtain an intra prediction mode of blocks existing at the position to configure a list. In addition, by adding a planar mode and a DC mode between the scan orders of the spatial neighboring blocks, for example, BL->L->AL->planar->DC->A->AR may be scanned. However, the order of intra prediction modes added between the scan orders of the spatial neighboring blocks is not limited thereto, and the scan order of upper neighboring blocks or left neighboring blocks among the scan orders of the spatial neighboring blocks is not limited thereto.

Table 1 below is a comparison table between the conventional scanning method and the most probable intra prediction mode list configuration according to an embodiment of the present invention.

Index of the most probable intra prediction mode list (Idx_MPM_list) current block in horizontal direction
(Fig. 15a) current block in vertical direction
(Fig. 15b) conventional method
(JEM) Method according to an embodiment of the present invention conventional method
(JEM) Method according to an embodiment of the present invention 0 L AR L BL One A A A L 2 playa AL playa AL 3 DC playa DC playa 4 BL DC BL DC 5 AR L AR AR 6 AL BL AL A

In this case, the overlapping intra prediction mode during scanning of neighboring blocks may not be added to the list of most probable intra prediction modes. In addition, the number of neighboring blocks and positions of neighboring blocks considered for constructing the list of most probable intra prediction modes of the current block may not be limited to the present invention. The number of most probable intra prediction modes constituting the list is not limited to the embodiment of the present invention.

In addition, the intra prediction of the current block may further include applying a smoothing filter to neighboring blocks of the current block to perform smoothing. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks of the current block.

In an embodiment, the neighboring blocks may include left neighboring blocks and upper neighboring blocks, and the smoothing filter may use a different filter for each of the left neighboring blocks and the upper neighboring blocks. For example, when the current block has a rectangular shape, the A intra smoothing filter may be used for the left neighboring blocks, and the B intra smoothing filter may be applied to the upper neighboring blocks. In this way, the at least two filters may be applied according to spatial positions of the neighboring blocks.

In an embodiment, the intra smoothing filter may be determined according to a size or shape of a current block for which the intra prediction is performed. For example, when the current block has a rectangular shape, the A intra-smoothing filter is applied to a neighboring block in the longest direction among the horizontal or vertical sides of the current block, and the B intra-smoothing filter is applied to the horizontal direction of the current block. Alternatively, it may be applied to a neighboring block in a direction having a shorter length among vertical sides. In this case, the A intra smoothing filter may be a smoothing filter that tends to compress a signal more than the B intra smoothing filter. In addition, the information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one of a size, a shape, and a prediction mode for predicting the current block In consideration of the above, the decoding apparatus may select a plurality of candidate filters.

17 and 18 are schematic diagrams and flowcharts for explaining a method of constructing a list of most probable intra prediction modes of a current block by re-segmenting neighboring blocks into sub-blocks according to another embodiment of the present invention.

Referring to FIG. 17 , in order to construct a list of the most probable intra prediction modes of the current block 1710 , first, blocks located around the current block 1710 may be sub-divided into sub-block units ( S180 ). In FIG. 17 , the blocks located around the current block 1710 that are re-divided in units of sub-blocks are eight on the upper side of the current block 1710 and eight sub-blocks on the left side of the current block 1710 , or the sub-blocks. The position, number, and size of the are not limited thereto. In an embodiment, the position, number, and size of the sub-blocks may be determined based on the shape or size of the current block 1710 .

Thereafter, intra prediction modes of sub blocks may be obtained ( S181 ). A scan order for obtaining the most probable intra prediction mode of the current block 1710 may be determined according to the obtained intra prediction modes of the sub blocks ( S182 ). For example, when the frequency of intra prediction mode of sub-blocks located above the current block 1710 is greater than the frequency of intra prediction mode of sub-blocks located on the left, constructing the most probable intra prediction mode list The order of obtaining the intra prediction mode of the sub-blocks may be the sub-blocks located on the left, starting from the sub-blocks located on the upper side.

In an embodiment, the scan order may be changed according to the shape of the current block 1710 . For example, when the shape of the current block 1710 is a block in the vertical direction, the list may be constructed by first acquiring an intra prediction mode from sub-blocks located on the left. Also, in another embodiment, the scan order may be fixed in the same order regardless of the shape of the current block 1710 or the frequency of intra prediction modes of neighboring sub-blocks. For example, in order to construct the most probable intra prediction mode list, a method of always scanning from the left sub-block to the upper sub-block or scanning from the upper sub-block to the left sub-block may be used.

As described above, by obtaining the intra prediction modes of the neighboring sub-blocks from the neighboring sub-blocks located in the vicinity of the current block and constructing a list of the most probable intra prediction modes, as the size of the prediction block increases, a small number of fixed It is possible to provide a method and apparatus for encoding or decoding a video signal that can solve the disadvantage that the intra prediction mode of the current block may be different from the intra prediction mode of the current block.

In addition, the intra prediction encoding of the current block may further include smoothing by applying a smoothing filter to neighboring blocks of the current block. There may be at least two smoothing filters, and the at least two smoothing filters may be adaptively applied to neighboring blocks of the current block.

In an embodiment, the neighboring blocks may include left neighboring blocks and upper neighboring blocks, and the smoothing filter may use a different filter for each of the left neighboring blocks and the upper neighboring blocks. For example, when the current block has a rectangular shape, the A intra smoothing filter may be used for the left neighboring blocks, and the B intra smoothing filter may be applied to the upper neighboring blocks. In this way, the at least two filters may be applied according to spatial positions of the neighboring blocks.

In an embodiment, the intra smoothing filter may be determined according to a size or shape of a current block for which the intra prediction is performed. For example, when the current block has a rectangular shape, the A intra-smoothing filter is applied to a neighboring block in the longest direction among the horizontal or vertical sides of the current block, and the B intra-smoothing filter is applied to the horizontal direction of the current block. Alternatively, it may be applied to a neighboring block in a direction having a shorter length among vertical sides. In this case, the A intra smoothing filter may be a smoothing filter that tends to compress a signal more than the B intra smoothing filter. In addition, the information on the at least two or more intra smoothing filters may be preset and transmitted from the encoding device or preset in the decoding device, but at least one of a size, a shape, and a prediction mode for predicting the current block In consideration of the above, the decoding apparatus may select a plurality of candidate filters.

It is common in the art to which the present invention pertains that the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and that various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be clear to those who have knowledge.

Claims (22)

determining the shape of the current block;
determining any one or more of positions and numbers of neighboring blocks that obtain the most probable intra prediction mode of the current block according to the determined shape; and
obtaining a list of most probable intra prediction modes of the current block based on the determined intra prediction modes of the neighboring blocks;
The determined neighboring blocks include both left neighboring blocks and upper neighboring blocks,
When the horizontal length of the current block is longer than the vertical length, the number of the upper neighboring blocks is more determined as the neighboring blocks than the number of the left neighboring blocks,
When the vertical length of the current block is longer than the horizontal length, the number of the left neighboring blocks is more determined as the neighboring blocks than the number of the upper neighboring blocks. The method of claim 1,
The determining step is
and determining by comparing the horizontal length and the vertical length of the current block. The method of claim 1,
The determining comprises determining based on at least one of horizontal and vertical length information, division information, direction information, and pixel information of the current block. delete The method of claim 1,
and smoothing the neighboring blocks by applying at least two filters to the neighboring blocks of the current block. determining shapes of neighboring blocks of the current block;
determining a scan order of neighboring blocks for obtaining the most probable intra prediction mode of the current block according to the determined shape; and
obtaining a list of most probable intra prediction modes of the current block from the neighboring blocks according to the determined order;
The determined neighboring blocks include both left neighboring blocks and upper neighboring blocks,
The step of determining the scan order comprises:
When the size of the left neighboring blocks is larger than the size of the upper neighboring blocks, the intra prediction modes of the left neighboring blocks are first scanned and included in the most probable intra prediction mode list,
When the size of the upper neighboring blocks is larger than the size of the left neighboring blocks, the intra prediction modes of the upper neighboring blocks are scanned first and included in the list of the most probable intra prediction modes. Way. 7. The method of claim 6,
The determining step is
The decoding method of a video signal, characterized in that based on sizes of the left neighboring blocks and the upper neighboring blocks. delete 7. The method of claim 6,
The video signal decoding method, characterized in that the neighboring blocks are blocks determined by the intra prediction mode. 7. The method of claim 6,
and smoothing the neighboring blocks by applying at least two filters to the neighboring blocks of the current block. obtaining a shape and a prediction mode of a neighboring block of the current block;
determining a scan order of the neighboring blocks for obtaining the most probable intra prediction mode of the current block based on the shape and the prediction mode; and
obtaining a list of most probable intra prediction modes of the current block from the neighboring blocks according to the determined order;
The determined neighboring blocks include left neighboring blocks and upper neighboring blocks,
determining the scan order.
The decoding method of a video signal, characterized in that, among the left neighboring blocks and the upper neighboring blocks, neighboring blocks having more blocks obtained by intra prediction are preferentially scanned. delete 12. The method of claim 11,
The step of obtaining the prediction mode of the neighboring block comprises:
dividing the periphery of the current block into sub-blocks; and
and obtaining prediction modes of the divided sub-blocks. 12. The method of claim 11,
and smoothing the neighboring blocks by applying at least two filters to the neighboring blocks of the current block. determining the shape of the current block;
determining a scan order of neighboring blocks for obtaining the most probable intra prediction mode of the current block according to the determined shape;
obtaining a list of most probable intra prediction modes of the current block based on intra prediction modes of the neighboring blocks according to the determined scan order,
The determined neighboring blocks include both left neighboring blocks and upper neighboring blocks,
The step of determining the scanning method comprises:
When the horizontal length of the current block is longer than the vertical length of the current block,
scan the upper neighboring blocks before the left neighboring blocks,
When the vertical length of the current block is longer than the horizontal length of the current block,
and determining to scan the left neighboring blocks before the upper neighboring blocks. 16. The method of claim 15,
The determining step is
and determining based on at least one of division information, direction information, and pixel information of the current block as a result of comparing the horizontal length of the current block and the vertical length of the current block. delete 16. The method of claim 15,
and smoothing the neighboring blocks by applying at least two filters to the neighboring blocks of the current block. dividing blocks located in the vicinity of the current block into neighboring sub-blocks; and
acquiring intra prediction modes of each of the neighboring sub-blocks,
The neighboring sub-blocks include left neighboring sub-blocks and upper neighboring sub-blocks,
For the neighboring sub-blocks, the location and number of the neighboring sub-blocks are determined based on any one or more of the size and shape of the current block,
When the horizontal length of the current block is longer than the vertical length, the number of the upper neighboring blocks is more determined as the neighboring blocks than the number of the left neighboring blocks,
When the vertical length of the current block is longer than the horizontal length, the number of the left neighboring blocks is more determined as the neighboring blocks than the number of the upper neighboring blocks. 20. The method of claim 19,
and determining an order of obtaining a most probable intra prediction mode constituting a list of most probable intra prediction modes of the current block based on the obtained intra prediction mode. 20. The method of claim 19,
and smoothing the neighboring subblocks by applying at least two filters to the neighboring subblocks of the current block. a block determination unit for determining the shape or prediction mode of the current block or neighboring blocks of the current block;
an MPM list construction method determining unit for determining at least one of a position, a number, and a scan order of the neighboring blocks for obtaining the most probable intra prediction mode of the current block according to the determined result; and
an MPM list construction unit configured to construct the most probable intra prediction mode list of the current block based on the intra prediction modes of the neighboring blocks according to the determined configuration method;
The determined neighboring blocks include both left neighboring blocks and upper neighboring blocks,
When the horizontal length of the current block is longer than the vertical length, the number of the upper neighboring blocks is more determined as the neighboring blocks than the number of the left neighboring blocks,
When the vertical length of the current block is longer than the horizontal length, the number of the left neighboring blocks is more determined as the neighboring blocks than the number of the upper neighboring blocks.

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