KR20200005207A - A method for encoding and decoding video using a motion compensation and filtering - Google Patents

Abstract

According to an embodiment of the present invention, an image decoding method comprises: a step of dividing a picture of an image into a plurality of coding units which are basic units in which an inter prediction or an intra prediction is performed and determining a target block for decoding a coding unit by dividing the picture or the divided coding unit into a quad tree, binary tree, or ternary tree structure; and a step of adaptively determining a sub-block motion compensation mode corresponding to a sub-block of the target block on the basis of the division information of the target block. Therefore, coding efficiency for a high resolution image can be increased.

Description

Image decoding and encoding method for processing motion compensation and filtering {A METHOD FOR ENCODING AND DECODING VIDEO USING A MOTION COMPENSATION AND FILTERING}

The present invention relates to image encoding and decoding, and more particularly, to a method for performing prediction and transformation by dividing a moving picture into a plurality of blocks.

In the image compression method, one picture is divided into a plurality of blocks having a predetermined size and encoding is performed. In addition, inter prediction and intra prediction techniques that remove redundancy between pictures are used to increase compression efficiency.

In this case, a residual signal is generated by using intra prediction and inter prediction, and the reason for obtaining the residual signal is that when coding with the residual signal, the amount of data is small and the data compression ratio is high, and the better the prediction, the residual signal. This is because the value of becomes small.

The intra prediction method predicts data of the current block by using pixels around the current block. The difference between the actual value and the predicted value is called the residual signal block. In the case of HEVC, the intra prediction method is increased from nine prediction modes used in H.264 / AVC to 35 prediction modes to further refine the prediction.

In the case of the inter prediction method, the most similar block is found by comparing the current block with blocks in neighboring pictures. At this time, the position information (Vx, Vy) of the found block is called a motion vector. The difference between pixel values in a block between the current block and the prediction block predicted by the motion vector is called a residual signal block (motion-compensated residual block).

As the intra prediction and the inter prediction are further subdivided, the amount of data of the residual signal is reduced, but the amount of computation for processing a video has greatly increased.

In particular, there is a difficulty in implementing a pipeline due to the increased complexity in determining a segmentation structure in a picture for encoding and decoding an image. It may not be suitable for coding.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an image processing method suitable for encoding and decoding a high resolution image and processing an efficient motion compensation and filtering, and an image decoding and encoding method using the same.

In the image decoding method according to an embodiment of the present invention for solving the above problems, in the image decoding method, a plurality of pictures of the picture is a basic unit in which inter prediction or intra prediction is performed; Decoding a coding unit that is divided into Coding Units of and dividing the picture or the divided coding unit into a quad tree, a binary tree, or a ternary tree structure Determining a target block for the; And adaptively determining a sub block motion compensation mode corresponding to the sub block of the target block based on the split information of the target block.

An image decoding apparatus according to an embodiment of the present invention for solving the above problems includes a plurality of coding units in which a picture of an image is a basic unit in which inter prediction or intra prediction is performed. And a target block for decoding a coding unit obtained by dividing the picture or the divided coding unit into a quad tree, a binary tree, or a ternary tree structure. Divider; And a subblock motion compensation determiner configured to adaptively determine a subblock motion compensation mode corresponding to the subblock of the target block based on the split information of the target block.

In the image encoding method according to an embodiment of the present invention for solving the above problems, in the image encoding method, a plurality of pictures of the picture is a basic unit that is performed inter prediction or intra prediction (inter prediction) is performed; Decoding a coding unit that is divided into Coding Units of and dividing the picture or the divided coding unit into a quad tree, a binary tree, or a ternary tree structure Determining a target block for the; And adaptively determining a sub block motion compensation mode corresponding to the sub block of the target block based on the split information of the target block.

According to an embodiment of the present invention, a coding unit, which is a basic unit on which inter prediction or intra prediction is performed, may be divided into a complex tree structure including a quad tree, a binary tree, and a ternary tree, and corresponding to a sub block of a target block. By adaptively determining the sub-block motion compensation mode, the motion compensation efficiency and the filtering effect corresponding to the diversified block shape can be improved, and the coding efficiency for the high resolution image can be improved.

In addition, according to an exemplary embodiment of the present invention, in performing prediction in units of coding units and sub-blocks, since prediction is performed by partially reflecting pixels corresponding to positions referenced by spatially adjacent blocks, motion compensation efficiency corresponding to diversified block types And the filtering effect can be improved and the coding efficiency for the high resolution image can be improved.

1 is a block diagram illustrating a configuration of an image encoding apparatus according to an embodiment of the present invention.
2 to 5 are diagrams for describing a first exemplary embodiment of a method of dividing and processing an image in block units.
6 is a block diagram illustrating an embodiment of a method of performing inter prediction in an image encoding apparatus.
7 is a block diagram illustrating a configuration of an image decoding apparatus according to an embodiment of the present invention.
8 is a block diagram illustrating an embodiment of a method of performing inter prediction in an image decoding apparatus.
FIG. 9 is a diagram for describing a second exemplary embodiment of a method of dividing and processing an image into blocks.
FIG. 10 is a diagram illustrating an embodiment of a syntax structure used to divide and process an image in block units.
FIG. 11 is a diagram for describing a third exemplary embodiment of a method of dividing and processing an image into blocks.
12 is a diagram for describing an embodiment of a method of configuring a transform unit by dividing a coding unit into a binary tree structure.
FIG. 13 is a diagram for describing a fourth exemplary embodiment of a method of dividing and processing an image into blocks.
14 to 16 are diagrams for describing still another example of a method of dividing and processing an image into blocks.
17 and 18 are diagrams for describing embodiments of a method of determining a partition structure of a transform unit by performing rate distortion optimization (RDO).
19 to 22 are views for explaining a composite partition structure according to another embodiment of the present invention.
23 illustrates a complex splitting processing process according to another exemplary embodiment of the present invention.
24 is a block diagram illustrating a motion compensation predictor according to another embodiment of the present invention.
25 is a flowchart illustrating an adaptive subblock motion compensation process based on subblock size and partition information.
FIG. 26 is a flowchart illustrating a filtering process of a decoding apparatus, according to an embodiment of the present invention. FIG. 27 is a flowchart illustrating an adaptive filter application according to an embodiment of the present invention.
28 to 29 are diagrams for describing signaling of block division information and header information according to an embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described concretely with reference to drawings. In describing the embodiments of the present specification, when it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present specification, the detailed description thereof will be omitted.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that another component may be present in between. Should be. In addition, the content described as "include" a specific configuration in the present invention does not exclude a configuration other than the configuration, it means that additional configuration may be included in the scope of the technical idea of the present invention or the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

In addition, the components shown in the embodiments of the present invention are shown independently to represent different characteristic functions, and do not mean that each component is made of separate hardware or one software component unit. In other words, each component is included in each component for convenience of description, and at least two of the components may be combined into one component, or one component may be divided into a plurality of components to perform a function. Integrated and separate embodiments of the components are also included within the scope of the present invention without departing from the spirit of the invention.

In addition, some of the components may not be essential components for performing essential functions in the present invention, but may be optional components for improving performance. The present invention can be implemented including only the components essential for implementing the essentials of the present invention except for the components used for improving performance, and the structure including only the essential components except for the optional components used for improving performance. Also included in the scope of the present invention.

1 is a block diagram illustrating a configuration of an image encoding apparatus according to an embodiment of the present invention. The image encoding apparatus 10 may include a picture divider 110, a transform unit 120, a quantization unit 130, and a scanning unit. The unit 131, the entropy encoder 140, the intra predictor 150, the inter predictor 160, the inverse quantizer 135, the inverse transformer 125, the post processor 170, and the picture storage 180 ), A subtractor 190 and an adder 195.

Referring to FIG. 1, the picture dividing unit 110 analyzes an input video signal, divides a picture into coding units, determines a prediction mode, and determines a size of a prediction unit for each coding unit.

In addition, the picture splitter 110 sends the prediction unit to be encoded to the intra predictor 150 or the inter predictor 160 according to a prediction mode (or a prediction method). In addition, the picture dividing unit 110 sends the prediction unit to be encoded to the subtracting unit 190.

Here, a picture of an image may be composed of a plurality of slices, and the slice may be divided into a plurality of coding tree units (CTUs) which are basic units for dividing a picture.

The coding tree unit may be divided into one or two coding units (CUs), which are basic units on which inter prediction or intra prediction is performed.

The coding unit (CU) may be divided into one or more prediction units (PUs), which are basic units on which prediction is performed.

In this case, the encoding apparatus 10 determines one of inter prediction and intra prediction as a prediction method for each of the divided coding units (CUs), but differently predicts a prediction block for each prediction unit (PU). Can be generated.

Meanwhile, the coding unit CU may be divided into one or two transform units (TUs), which are basic units for transforming a residual block.

In this case, the picture dividing unit 110 may transmit the image data to the subtracting unit 190 in a block unit (for example, a prediction unit (PU) or a transformation unit (TU)) divided as described above.

Referring to FIG. 2, a coding tree unit (CTU) having a maximum size of 256 × 256 pixels may be divided into a quad tree structure and divided into four coding units (CUs) having a square shape.

The four coding units (CUs) having the square shape may be re-divided into quad tree structures, respectively, and the depth of the coding units CU divided into quad tree structures as described above may be any one of 0 to 3. It can have one integer value.

The coding unit CU may be divided into one or two or more prediction units (PUs) according to the prediction mode.

In the case of the intra prediction mode, when the size of the coding unit CU is 2Nx2N, the prediction unit PU may have a size of 2Nx2N shown in FIG. 3A or NxN shown in FIG. 3B. have.

Meanwhile, in the inter prediction mode, when the size of the coding unit CU is 2Nx2N, the prediction unit PU is 2Nx2N shown in FIG. 4A, 2NxN shown in FIG. 4B, and FIG. 4. Nx2N shown in (c) of FIG. 4, NxN shown in (d) of FIG. 4, 2NxnU shown in (e) of FIG. 4, 2NxnD shown in (f) of FIG. 4, shown in (g) of FIG. It may have a size of any one of nLx2N and nRx2N shown in (h) of FIG.

Referring to FIG. 5, the coding unit CU may be divided into a quad tree structure and divided into four transform units TUs having a square shape.

The four transform units (TUs) having a square shape may be re-divided into quad tree structures, and the depth of the transform units (TUs) divided into quad tree structures as described above may be any one of 0 to 3. It can have one integer value.

Here, when the coding unit CU is in the inter prediction mode, the prediction unit PU and the transform unit TU split from the coding unit CU may have a partition structure that is independent of each other.

When the coding unit CU is in the intra prediction mode, the transform unit TU split from the coding unit CU cannot be larger than the size of the prediction unit PU.

In addition, the transform unit TU divided as described above may have a maximum size of 64x64 pixels.

The transform unit 120 converts a residual block that is a residual signal between the original block of the input prediction unit PU and the prediction block generated by the intra predictor 150 or the inter predictor 160, and the transform is performed. It may be performed using the unit (TU) as a basic unit.

In the transformation process, different transform matrices may be determined according to a prediction mode (intra or inter), and since the residual signal of intra prediction has a direction according to the intra prediction mode, the transform matrix may be adaptively determined according to the intra prediction mode. have.

The transform unit may be transformed by two (horizontal and vertical) one-dimensional transform matrices. For example, in the case of inter prediction, one predetermined transform matrix may be determined.

On the other hand, in the case of intra prediction, when the intra prediction mode is horizontal, the probability of the residual block having the directionality in the vertical direction increases, so a DCT-based integer matrix is applied in the vertical direction, and DST-based or in the horizontal direction. Apply KLT-based integer matrix. When the intra prediction mode is vertical, an integer matrix based on DST or KLT may be applied in the vertical direction and a DCT based integer matrix in the horizontal direction.

In addition, in the DC mode, a DCT based integer matrix may be applied in both directions.

In the case of intra prediction, a transform matrix may be adaptively determined based on the size of a transform unit (TU).

The quantization unit 130 determines a quantization step size for quantizing the coefficients of the residual block transformed by the transform matrix, and the quantization step size may be determined for each quantization unit having a predetermined size or more.

The size of the quantization unit may be 8x8 or 16x16, and the quantization unit 130 quantizes coefficients of the transform block using a quantization matrix determined according to the quantization step size and the prediction mode.

In addition, the quantization unit 130 may use the quantization step size of the quantization unit adjacent to the current quantization unit as the quantization step size predictor of the current quantization unit.

The quantization unit 130 may search for the left quantization unit, the upper quantization unit, and the upper left quantization unit of the current quantization unit and generate a quantization step size predictor of the current quantization unit using one or two valid quantization step sizes. have.

For example, the quantization unit 130 may determine a valid first quantization step size found in the order as a quantization step size predictor, or determine an average value of two valid quantization step sizes found in the order as a quantization step size predictor, or If only one quantization step size is valid, this may be determined as a quantization step size predictor.

When the quantization step size predictor is determined, the quantization unit 130 transmits a difference value between the quantization step size and the quantization step size predictor of the current quantization unit to the entropy encoder 140.

On the other hand, the left coding unit, the upper coding unit, the upper left coding unit of the current coding unit does not all exist. Or there may be a coding unit previously present in the coding order within the largest coding unit.

Accordingly, candidates may be quantization step sizes of the quantization units adjacent to the current coding unit and the quantization unit immediately before the coding order within the maximum coding unit.

In this case, priority is set in the order of 1) the left quantization unit of the current coding unit, 2) the upper quantization unit of the current coding unit, 3) the upper left quantization unit of the current coding unit, and 4) the quantization unit immediately preceding the coding order. Can be. The order may be reversed and the upper left quantization unit may be omitted.

Meanwhile, the transform block quantized as described above is transferred to the inverse quantization unit 135 and the scanning unit 131.

The scanning unit 131 scans the coefficients of the quantized transform block and converts them into one-dimensional quantization coefficients. In this case, since the distribution of coefficients of the transform block after quantization may depend on the intra prediction mode, the scanning method is applied to the intra prediction mode. Can be determined accordingly.

Further, the coefficient scanning scheme may be determined differently according to the size of the transform unit, and the scan pattern may vary according to the directional intra prediction mode, in which case the scanning order of the quantization coefficients may be scanned in the reverse direction.

When the quantized coefficients are divided into a plurality of subsets, the same scan pattern may be applied to the quantization coefficients in each subset, and a zigzag scan or a diagonal scan may be applied to the scan patterns between the subsets.

Meanwhile, the scan pattern is preferably scanned in the forward direction from the main subset including DC to the remaining subsets, but the reverse direction is also possible.

In addition, a scan pattern between subsets may be set to be identical to a scan pattern of quantized coefficients in a subset, and the scan pattern between subsets may be determined according to an intra prediction mode.

Meanwhile, the encoding apparatus 10 may include information indicative of the position of the last non-zero quantization coefficient and the position of the last non-zero quantization coefficient in each subset in the transform unit PU to include the decoding apparatus ( 20).

The inverse quantization unit 135 inverse quantizes the quantized coefficients as described above, and the inverse transform unit 125 performs inverse transformation in units of transform units (TUs) to restore the inverse quantized transform coefficients into a residual block of a spatial domain. can do.

The adder 195 may generate a reconstructed block by adding the residual block reconstructed by the inverse transform unit 125 and the received prediction block from the intra predictor 150 or the inter predictor 160.

In addition, the post-processing unit 170 may perform a deblocking filtering process to remove a blocking effect occurring in the reconstructed picture, and a sample adaptive offset to compensate for a difference value from the original image in units of pixels. The SAO) application process and the coding unit may perform post-processing such as an adaptive loop filtering (ALF) process to compensate for the difference from the original image.

The deblocking filtering process may be applied to the boundary of the prediction unit (PU) or transform unit (TU) having a size of a predetermined size or more.

For example, the deblocking filtering process may include determining a boundary to filter, determining a boundary filtering strength to be applied to the boundary, determining whether to apply a deblocking filter, If it is determined to apply the deblocking filter, the method may include selecting a filter to be applied to the boundary.

On the other hand, whether the deblocking filter is applied depends on whether i) the boundary filtering intensity is greater than 0 and ii) the degree of change of pixel values at the boundary portions of two blocks (P block, Q block) adjacent to the boundary to be filtered. The value represented may be determined by whether the value is smaller than the first reference value determined by the quantization parameter.

It is preferable that the said filter is at least 2 or more. When the absolute value of the difference between two pixels positioned at the block boundary is greater than or equal to the second reference value, a filter that performs relatively weak filtering is selected.

The second reference value is determined by the quantization parameter and the boundary filtering intensity.

In addition, the sample adaptive offset (SAO) application process is to reduce the distortion (distortion) between the pixel and the original pixel in the image to which the deblocking filter is applied, the sample adaptive offset (SAO) application process in the unit of picture or slice. Whether to perform may be determined.

The picture or slice may be divided into a plurality of offset regions, and an offset type may be determined for each offset region, and the offset type may be a predetermined number of edge offset types (eg, four) and two band offsets. It can include a type.

For example, when the offset type is an edge offset type, an edge type to which each pixel belongs is determined and an offset corresponding thereto is applied, and the edge type may be determined based on a distribution of two pixel values adjacent to the current pixel. have.

The adaptive loop filtering (ALF) process may perform filtering based on a value obtained by comparing a reconstructed image and an original image that have undergone a deblocking filtering process or an adaptive offset application process.

The picture storage unit 180 receives the post-processed image data from the post-processing unit 170 and restores the image in a picture unit, and the picture may be an image in a frame unit or an image in a field unit.

The inter prediction unit 160 may perform motion estimation using at least one or more reference pictures stored in the picture storage unit 180, and may determine a reference picture index and a motion vector indicating the reference picture.

In this case, a prediction block corresponding to a prediction unit to be encoded may be extracted from a reference picture used for motion estimation among a plurality of reference pictures stored in the picture storage unit 180 according to the determined reference picture index and the motion vector. have.

The intra predictor 150 may perform intra prediction encoding by using the reconstructed pixel value inside the picture in which the current prediction unit is included.

The intra prediction unit 150 may receive the current prediction unit to be predictively encoded, and perform intra prediction by selecting one of a preset number of intra prediction modes according to the size of the current block.

The intra predictor 150 adaptively filters the reference pixel to generate the intra prediction block, and generates reference pixels using the available reference pixels when the reference pixel is not available.

The entropy encoder 140 may entropy encode quantization coefficients quantized by the quantizer 130, intra prediction information received from the intra predictor 150, motion information received from the inter predictor 160, and the like. .

FIG. 6 is a block diagram illustrating an example of a configuration for performing inter prediction in the encoding apparatus 10. The inter prediction encoder illustrated in FIG. 6 includes a motion information determiner 161 and a motion information encoding mode determiner 162. FIG. , Motion information encoder 163, prediction block generator 164, residual block generator 165, residual block encoder 166, and multiplexer 167.

Referring to FIG. 6, the motion information determiner 161 determines motion information of the current block, the motion information includes a reference picture index and a motion vector, and the reference picture index is any one of a previously coded and reconstructed picture. Can be represented.

When the current block is unidirectional inter prediction coded, it represents one of the reference pictures belonging to list 0 (L0), and when the current block is bidirectional predictively coded, it is a reference picture indicating one of the reference pictures of list 0 (L0). It may include an index and a reference picture index indicating one of the reference pictures of the list 1 (L1).

In addition, when the current block is bidirectional predictively coded, the current block may include an index indicating one or two pictures of reference pictures of the composite list LC generated by combining the list 0 and the list 1.

The motion vector indicates a position of a prediction block in a picture indicated by each reference picture index, and the motion vector may be in pixel units (integer units) or sub pixel units.

For example, the motion vector may have a precision of 1/2, 1/4, 1/8 or 1/16 pixels, and if the motion vector is not an integer unit, the prediction block may be generated from pixels of an integer unit. Can be.

The motion information encoding mode determiner 162 may determine an encoding mode for the motion information of the current block, and the encoding mode may be exemplified as one of a skip mode, a merge mode, and an AMVP mode.

The skip mode is applied when there are skip candidates having the same motion information as the motion information of the current block and the residual signal is 0. The skip mode is that the current block, which is the prediction unit PU, has a size equal to that of the coding unit CU. Can be applied when

The merge mode is applied when there is a merge candidate having the same motion information as the motion information of the current block, and the merge mode includes a residual signal when the current block has a different size or the same size as the coding unit CU. Applies in the case. Meanwhile, the merge candidate and the skip candidate may be the same.

The AMVP mode is applied when the skip mode and the merge mode are not applied, and an AMVP candidate having a motion vector most similar to the motion vector of the current block may be selected as an AMVP predictor.

However, the encoding mode is a process other than the illustrated method, and may adaptively include a more detailed motion compensation prediction encoding mode. The adaptively determined motion compensation prediction modes include the AMVP mode, merge mode, and skip mode described above, as well as FRUC (FRAME RATE UP-CONVERSION) mode and BIO (BI-DIRECTIONAL OPTICAL FLOW), which are currently proposed as a new motion compensation prediction mode. (AMP) mode, AMP (AFFINE MOTION PREDICTION) mode, OBMC (OVERLAPPED BLOCK MOTION COMPENSATION) mode, DMVR (DECODER-SIDE MOTION VECTOR REFINEMENT) mode, ATMVP (Alternative temporal motion vector prediction) mode, STMVP (Spatial-temporal motion vector prediction) mode The method may further include at least one of a mode and a local illumination compensation (LIC) mode, and may be adaptively determined according to a predetermined condition.

The motion information encoder 163 may encode motion information according to a method determined by the motion information encoding mode determiner 162.

For example, the motion information encoder 163 may perform a merge motion vector encoding process when the motion information encoding mode is a skip mode or a merge mode, and may perform an AMVP encoding process when the motion information encoding mode is an AMVP mode.

The prediction block generator 164 generates a prediction block by using the motion information of the current block. When the motion vector is an integer unit, the prediction block generator 164 copies the block corresponding to the position indicated by the motion vector in the picture indicated by the reference picture index, and then copies the current block. Generate a predictive block of.

Meanwhile, when the motion vector is not an integer unit, the prediction block generator 164 may generate pixels of the prediction block from integer unit pixels in a picture indicated by the reference picture index.

In this case, the prediction pixel may be generated using an 8-tap interpolation filter for the luminance pixel, and the prediction pixel may be generated using a 4-tap interpolation filter for the chrominance pixel.

The residual block generator 165 generates a residual block using the current block and the prediction block of the current block. When the size of the current block is 2Nx2N, the residual block generator 165 uses the prediction block having a size of 2Nx2N corresponding to the current block and the current block. You can create a block.

On the other hand, when the size of the current block used for prediction is 2NxN or Nx2N, after obtaining the prediction block for each of the two 2NxN blocks constituting the 2Nx2N, the last prediction block of 2Nx2N size using the two 2NxN prediction blocks Can be generated.

In addition, a 2Nx2N sized residual block may be generated using the 2Nx2N sized prediction block, and overlap smoothing is applied to the pixels of the boundary part to eliminate discontinuity of the boundary parts of two prediction blocks having 2NxN size. Can be.

The residual block encoder 166 may divide the residual block into one or more transform units (TUs) so that each transform unit TU may be transform encoded, quantized, and entropy encoded.

The residual block encoder 166 may transform the residual block generated by the inter prediction method using an integer-based transform matrix, and the transform matrix may be an integer-based DCT matrix.

Meanwhile, the residual block encoder 166 uses a quantization matrix to quantize coefficients of the residual block transformed by the transform matrix, and the quantization matrix may be determined by a quantization parameter.

The quantization parameter is determined for each coding unit CU having a predetermined size or more, and when the current coding unit CU is smaller than the predetermined size, the first coding unit in the coding order among the coding units CU within the predetermined size ( Since only the quantization parameter of the CU) is encoded and the quantization parameter of the remaining coding unit CU is the same as the above parameter, it may not be encoded.

In addition, coefficients of the transform block may be quantized using a quantization matrix determined according to the quantization parameter and the prediction mode.

The quantization parameter determined for each coding unit CU having a predetermined size or more may be predictively encoded using the quantization parameter of the coding unit CU adjacent to the current coding unit CU.

A quantization parameter predictor of the current coding unit CU may be generated by searching in the order of the left coding unit CU and the upper coding unit CU of the current coding unit CU using one or two valid quantization parameters. have.

For example, the first valid quantization parameter found in the above order may be determined as a quantization parameter predictor, and the left first coding unit (CU) is searched in order of the coding unit immediately before the coding order to quantize the first valid quantization parameter. Can be determined by the parameter predictor.

The coefficients of the quantized transform block are scanned and converted into one-dimensional quantization coefficients, and the scanning scheme may be set differently according to the entropy encoding mode.

For example, inter prediction coded quantization coefficients may be scanned in a predetermined manner (zigzag or diagonal raster scan) when coded with CABAC, and different from the above method when coded with CAVLC. Can be.

For example, the scanning method may be determined according to zigzag in case of inter, the intra prediction mode in case of intra, and the coefficient scanning method may be determined differently according to the size of a transform unit.

Meanwhile, the scan pattern may vary according to the directional intra prediction mode, and the scanning order of the quantization coefficients may be scanned in the reverse direction.

The multiplexer 167 multiplexes the motion information encoded by the motion information encoder 163 and the residual signals encoded by the residual block encoder 166.

The motion information may vary according to an encoding mode. For example, in case of skip or merge, the motion information may include only an index indicating a predictor, and in the case of AMVP, the motion information may include a reference picture index, a differential motion vector, and an AMVP index of the current block. .

Hereinafter, an embodiment of the operation of the intra predictor 150 shown in FIG. 1 will be described in detail.

First, the intra prediction unit 150 receives the prediction mode information and the size of the prediction unit PU from the picture division unit 110, and stores the reference pixel in the picture storage unit to determine the intra prediction mode of the prediction unit PU. Read from 180.

The intra predictor 150 determines whether a reference pixel is generated by examining whether there is a reference pixel that is not available, and the reference pixels may be used to determine an intra prediction mode of the current block.

If the current block is located at the upper boundary of the current picture, pixels adjacent to the upper side of the current block are not defined. If the current block is located at the left boundary of the current picture, pixels adjacent to the left of the current block are not defined. It may be determined that the pixels are not available pixels.

In addition, even when the current block is located at the slice boundary and pixels adjacent to the upper or left side of the slice are not pixels that are first encoded and reconstructed, it may be determined that the pixels are not available pixels.

As described above, when there are no pixels adjacent to the left side or the upper side of the current block or there are no pre-coded and reconstructed pixels, the intra prediction mode of the current block may be determined using only the available pixels.

On the other hand, a reference pixel of a position that is not available may be generated by using the available reference pixels of the current block, for example, when the pixels of the upper block are not available, the upper pixel using some or all of the left pixels. Can be generated and vice versa.

That is, the reference pixel is generated by copying the available reference pixel at the position closest to the predetermined direction from the reference pixel at the position not available, or when the reference pixel is not available in the predetermined direction, the closest in the opposite direction. The reference pixel can be generated by copying the available reference pixel at the location.

Meanwhile, even when the upper or left pixels of the current block exist, it may be determined as a reference pixel that is not available according to the encoding mode of the block to which the pixels belong.

For example, when a block to which a reference pixel adjacent to an upper side of the current block belongs is a block that is inter-coded and reconstructed, the pixels may be determined as not available pixels.

In this case, reference pixels usable may be generated using pixels belonging to a block in which a block adjacent to the current block is intra-encoded, and information indicating that the encoding apparatus 10 determines available reference pixels according to an encoding mode. It transmits to the decoding apparatus 20.

The intra predictor 150 determines the intra prediction mode of the current block by using the reference pixels, and the number of intra prediction modes allowable in the current block may vary depending on the size of the block.

For example, if the size of the current block is 8x8, 16x16, 32x32, 34 intra prediction modes may exist, and if the size of the current block is 4x4, 17 intra prediction modes may exist.

The 34 or 17 intra prediction modes may be configured of at least one non-directional mode (non-directional mode) and a plurality of directional modes.

One or more non-directional modes may be DC mode and / or planar mode. When the DC mode and the planner mode are included in the non-directional mode, there may be 35 intra prediction modes regardless of the size of the current block.

In this case, two non-directional modes (DC mode and planner mode) and 33 directional modes may be included.

In the planner mode, the prediction block of the current block is formed by using at least one pixel value (or a prediction value of the pixel value, hereinafter referred to as a first reference value) and reference pixels positioned at the bottom-right side of the current block. Is generated.

The configuration of an image decoding apparatus according to an embodiment of the present invention may be derived from the configuration of the image encoding apparatus 10 described with reference to FIGS. 1 to 6. For example, as described with reference to FIGS. 1 to 6. By performing the same processes of the same image encoding method in reverse, the image can be decoded.

7 is a block diagram illustrating a configuration of a video decoding apparatus according to an embodiment of the present invention. The decoding apparatus 20 includes an entropy decoding unit 210, an inverse quantization / inverse transform unit 220, an adder 270, The post processor 250, the picture storage unit 260, the intra predictor 230, the motion compensation predictor 240, and the intra / inter switch 280 are provided.

The entropy decoder 210 receives and decodes a bit stream encoded by the image encoding apparatus 10, divides the bit stream into intra prediction mode indexes, motion information, quantization coefficient sequences, and the like, and decodes the decoded motion information into a motion compensation predictor ( 240).

The entropy decoder 210 transmits the intra prediction mode index to the intra predictor 230 and the inverse quantization / inverse transform unit 220, and transmits the inverse quantization coefficient sequence to the inverse quantization / inverse transform unit 220.

The inverse quantization / inverse transform unit 220 converts the quantization coefficient sequence into inverse quantization coefficients of a two-dimensional array, and selects one of a plurality of scanning patterns for the transformation, for example, the prediction mode of the current block (ie, , Intra prediction or inter prediction), and a scanning pattern may be selected based on the intra prediction mode.

The inverse quantization / inverse transform unit 220 restores the quantization coefficients by applying a quantization matrix selected from a plurality of quantization matrices to the inverse quantization coefficients of the two-dimensional array.

Meanwhile, different quantization matrices are applied according to the size of the current block to be reconstructed, and a quantization matrix may be selected based on at least one of the prediction mode and the intra prediction mode of the current block for the same size block.

The inverse quantization / inverse transform unit 220 inversely transforms the reconstructed quantization coefficients to reconstruct the residual block, and the inverse transform process may be performed using a transform unit (TU) as a basic unit.

The adder 270 reconstructs the image block by adding the residual block reconstructed by the inverse quantization / inverse transform unit 220 and the prediction block generated by the intra predictor 230 or the motion compensation predictor 240.

The post processor 250 may perform post-processing on the reconstructed image generated by the adder 270 to reduce deblocking artifacts due to image loss due to quantization by filtering or the like.

The picture storage unit 260 is a frame memory for storing a local decoded image that has been subjected to filter post-processing by the post-processor 250.

The intra predictor 230 restores the intra prediction mode of the current block based on the intra prediction mode index received from the entropy decoder 210, and generates a prediction block according to the restored intra prediction mode.

The motion compensation predictor 240 generates a prediction block for the current block from the picture stored in the picture storage unit 260 based on the motion vector information, and applies the selected interpolation filter when a motion compensation with a small precision is applied. Can be generated.

The intra / inter switch 280 may provide the adder 270 with the prediction block generated by either the intra predictor 230 or the motion compensation predictor 240 based on the encoding mode.

FIG. 8 is a block diagram illustrating an example of a configuration of performing inter prediction in the image decoding apparatus 20. The inter prediction decoder includes a demultiplexer 241, a motion information encoding mode determiner 242, and a merge mode motion. An information decoder 243, an AMVP mode motion information decoder 244, a selection mode motion information decoder 248, a predictive block generator 245, a residual block decoder 246, and a reconstructed block generator 247. It includes.

Referring to FIG. 8, the de-multiplexer 241 demultiplexes the currently encoded motion information and the encoded residual signals from the received bitstream, and transmits the demultiplexed motion information to the motion information encoding mode determiner 242. The demultiplexed residual signal may be transmitted to the residual block decoder 246.

The motion information encoding mode determiner 242 determines the motion information encoding mode of the current block. If the skip_flag of the received bitstream has a value of 1, the motion information encoding mode determiner 242 determines that the motion information encoding mode of the current block is encoded as the skip encoding mode. can do.

If the skip_flag of the received bitstream has a value of 0 and the motion information received from the de-multiplexer 241 has only a merge index, the motion information encoding mode determiner 242 determines the motion information encoding mode of the current block. It may be determined that is encoded in the merge mode.

In addition, the motion information encoding mode determiner 242 has a skip_flag of the received bitstream having a value of 0, and the motion information received from the demultiplexer 241 has a reference picture index, a differential motion vector, and an AMVP index. In this case, it may be determined that the motion information encoding mode of the current block is encoded in the AMVP mode.

The merge mode motion information decoder 243 is activated when the motion information encoding mode determiner 242 determines that the motion information encoding mode of the current block is a skip or merge mode, and the AMVP mode motion information decoder 244 moves. The information encoding mode determiner 242 may be activated when the motion information encoding mode of the current block is determined to be an AMVP mode.

The selection mode motion information decoder 248 may decode the motion information in a prediction mode selected from other motion compensation prediction modes except for the above-described AMVP mode, merge mode, and skip mode. The selection prediction mode may include a motion prediction mode that is more precise than the AMVP mode, and may be adaptively determined according to predetermined conditions (eg, block size and block partitioning information, signaling information present, block position, etc.). . Selective prediction modes are, for example, FRAME (FRAME RATE UP-CONVERSION) mode, BIO (BI-DIRECTIONAL OPTICAL FLOW) mode, AMP (AFFINE MOTION PREDICTION) mode, OBMC (OVERLAPPED BLOCK MOTION COMPENSATION) mode, DMVR (DECODER-SIDE) It may include at least one of a MOTION VECTOR REFINEMENT mode, an alternate temporal motion vector prediction (ATMVP) mode, a spatial-temporal motion vector prediction (STMVP) mode, and a local illumination compensation (LIC) mode.

The prediction block generator 245 generates the prediction block of the current block by using the motion information reconstructed by the merge mode motion information decoder 243 or the AMVP mode motion information decoder 244.

When the motion vector is an integer unit, the prediction block of the current block may be generated by copying a block corresponding to the position indicated by the motion vector in the picture indicated by the reference picture index.

On the other hand, when the motion vector is not an integer unit, pixels of the prediction block are generated from integer unit pixels in the picture indicated by the reference picture index. In this case, an interpolation filter of 8 taps is used for a luminance pixel and a chrominance pixel is used. Predictive pixels may be generated using a 4-tap interpolation filter.

The residual block decoder 246 entropy decodes the residual signal and inversely scans the entropy decoded coefficients to generate a two-dimensional quantized coefficient block, and the inverse scanning scheme may vary according to an entropy decoding scheme.

For example, when the CABAC-based decoding is performed, the reverse scanning method may be applied in a diagonal raster inverse scan manner and in the case of the CAVLC-based decoding in a zigzag inverse scanning manner. In addition, the inverse scanning scheme may be determined differently according to the size of the prediction block.

The residual block decoder 246 dequantizes the coefficient block generated as described above using an inverse quantization matrix, and reconstructs a quantization parameter to derive the quantization matrix. Here, the quantization step size may be reconstructed for each coding unit of a predetermined size or more.

The residual block decoder 260 inversely transforms the inverse quantized coefficient block to restore the residual block.

The reconstruction block generation unit 270 generates a reconstruction block by adding the prediction block generated by the prediction block generation unit 250 and the residual block generated by the residual block decoding unit 260.

Hereinafter, an embodiment of a process of reconstructing the current block through intra prediction will be described with reference to FIG. 7 again.

First, the intra prediction mode of the current block is decoded from the received bitstream, and for this purpose, the entropy decoder 210 may reconstruct the first intra prediction mode index of the current block by referring to one of the plurality of intra prediction mode tables. Can be.

As the table shared by the plurality of intra prediction mode tables encoding apparatus 10 and the decoding apparatus 20, any one table selected according to the distribution of intra prediction modes for a plurality of blocks adjacent to the current block may be applied. .

For example, if the intra prediction mode of the left block of the current block and the intra prediction mode of the upper block of the current block are the same, the first intra prediction mode index of the current block is restored by applying the first intra prediction mode table, and not the same. Otherwise, the second intra prediction mode table may be applied to restore the first intra prediction mode index of the current block.

As another example, when the intra prediction modes of the upper block and the left block of the current block are both the directional intra prediction mode, the direction of the intra prediction mode of the upper block and the direction of the intra prediction mode of the left block. If within this predetermined angle, the first intra prediction mode index is restored by applying the first intra prediction mode table, and if outside the predetermined angle, the first intra prediction mode index is applied by applying the second intra prediction mode table. You can also restore.

The entropy decoder 210 transmits the first intra prediction mode index of the reconstructed current block to the intra predictor 230.

The intra prediction unit 230 that receives the index of the first intra prediction mode may determine the maximum possible mode of the current block as the intra prediction mode of the current block when the index has the minimum value (ie, 0). .

Meanwhile, when the index has a value other than 0, the intra prediction unit 230 compares the index indicated by the maximum possible mode of the current block with the first intra prediction mode index, and as a result of the comparison, the first intra prediction mode. If the index is not smaller than the index indicated by the maximum possible mode of the current block, the intra prediction mode corresponding to the second intra prediction mode index obtained by adding 1 to the first intra prediction mode index is determined as the intra prediction mode of the current block. Otherwise, the intra prediction mode corresponding to the first intra prediction mode index may be determined as the intra prediction mode of the current block.

The intra prediction mode allowable for the current block may consist of at least one non-directional mode (non-directional mode) and a plurality of directional modes.

One or more non-directional modes may be DC mode and / or planar mode. In addition, either DC mode or planner mode may be adaptively included in the allowable intra prediction mode set.

To this end, information specifying the non-directional mode included in the allowable intra prediction mode set may be included in the picture header or the slice header.

Next, the intra predictor 230 reads reference pixels from the picture storage unit 260 to generate an intra prediction block, and determines whether there is a reference pixel that is not available.

The determination may be performed according to the presence or absence of reference pixels used to generate the intra prediction block by applying the decoded intra prediction mode of the current block.

Next, when it is necessary to generate the reference pixel, the intra predictor 230 may generate reference pixels at positions that are not available using the available reference pixels reconstructed in advance.

Definition of a reference pixel that is not available and a method of generating the reference pixel may be the same as the operation of the intra prediction unit 150 of FIG. 1, but generate an intra prediction block according to the decoded intra prediction mode of the current block. The reference pixels used to selectively recover may be selectively restored.

In addition, the intra prediction unit 230 determines whether to apply a filter to the reference pixels to generate the prediction block, that is, whether to apply filtering to the reference pixels to generate the intra prediction block of the current block. It may be determined based on the decoded intra prediction mode and the size of the current prediction block.

The problem of blocking artifacts is that the larger the block size is, the larger the block size can increase the number of prediction modes for filtering the reference pixels, but if the block is larger than the predetermined size can be seen as a flat area, the complexity is reduced The reference pixel may not be filtered for.

If it is determined that the filter is required to be applied to the reference pixel, the intra predictor 230 filters the reference pixels by using a filter.

At least two or more filters may be adaptively applied according to the degree of difference between the steps between the reference pixels. The filter coefficient of the filter is preferably symmetrical.

In addition, the above two filters may be adaptively applied according to the size of the current block. When the filter is applied, a narrow bandwidth filter is used for a small block, and a wide bandwidth filter is used for a large block. May be applied.

In the DC mode, since the prediction block is generated with the average value of the reference pixels, there is no need to apply a filter. In the vertical mode where the correlation is in the vertical direction, the filter does not need to be applied to the reference pixel, and the image is horizontal. It may not be necessary to apply a filter to the reference pixel even in a horizontal mode that is correlated in the direction.

As described above, whether filtering is applied is also related to the intra prediction mode of the current block, and thus, the reference pixel may be adaptively filtered based on the intra prediction mode of the current block and the size of the prediction block.

Next, the intra prediction unit 230 generates a prediction block using reference pixels or filtered reference pixels according to the reconstructed intra prediction mode, and the generation of the prediction block is the same as the operation of the encoding apparatus 10. As such, detailed description thereof will be omitted.

The intra prediction unit 230 determines whether to filter the generated prediction block, and the filtering may be determined by using information included in a slice header or a coding unit header or according to an intra prediction mode of the current block.

When determining that the generated prediction block is to be filtered, the intra predictor 230 may generate a new pixel by filtering pixels at a specific position of the generated prediction block by using available reference pixels adjacent to the current block. .

For example, in the DC mode, a prediction pixel in contact with reference pixels among the prediction pixels may be filtered using a reference pixel in contact with the prediction pixel.

Therefore, the prediction pixels are filtered using one or two reference pixels according to the positions of the prediction pixels, and the filtering of the prediction pixels in the DC mode may be applied to the prediction blocks of all sizes.

Meanwhile, in the vertical mode, prediction pixels in contact with the left reference pixel among the prediction pixels of the prediction block may be changed by using reference pixels other than the upper pixel used to generate the prediction block.

Similarly, in the horizontal mode, the prediction pixels in contact with the upper reference pixel among the generated prediction pixels may be changed using reference pixels other than the left pixel used to generate the prediction block.

In this manner, the current block may be reconstructed using the prediction block of the current block reconstructed and the residual block of the decoded current block.

FIG. 9 illustrates a second exemplary embodiment of a method of dividing and processing an image into blocks.

Referring to FIG. 9, a coding tree unit (CTU) having a maximum size of 256 × 256 pixels may be first divided into a quad tree structure and divided into four coding units (CUs) having a square shape.

Here, at least one of the coding units divided into the quad tree structure may be divided into a binary tree structure and re-divided into two coding units (CUs) having a rectangular shape.

Meanwhile, at least one of the coding units divided into the quad tree structure may be divided into a quad tree structure and re-divided into four coding units (CUs) having a square shape.

At least one of the coding units re-divided into the binary tree structure may be divided into two binary tree structures and divided into two coding units (CUs) having a square or rectangular shape.

Meanwhile, at least one of the coding units re-divided into the quad tree structure may be divided into a quad tree structure or a binary tree structure and divided into coding units (CUs) having a square or rectangular shape.

CUs divided and configured into a binary tree structure as described above may be used for prediction and transformation without being further divided. In this case, the binary partitioned CU may include a coding block (CB), which is a block unit that actually performs encoding / decoding, and syntax corresponding to the coding block. That is, the sizes of the prediction unit PU and the transform unit TU belonging to the coding block CB as shown in FIG. 9 may be equal to the size of the coding block CB.

The coding unit split into the quad tree structure as described above may be split into one or two prediction units (PUs) using the method described with reference to FIGS. 3 and 4.

In addition, the coding unit divided into the quad tree structure as described above may be divided into one or more transform units (TUs) by using the method as described with reference to FIG. 5, and the divided transform units (TU) May have a maximum size of 64x64 pixels.

FIG. 10 illustrates an embodiment of a syntax structure used to divide and process an image in block units.

10 and 9, a block structure according to an embodiment of the present invention may be determined through split_cu_flag indicating whether a quad tree is split and binary_split_flag indicating whether a binary tree is split.

For example, whether to split the coding unit CU as described above may be indicated using split_cu_flag. After the quad tree division, the binary_split_flag indicating whether the binary division is performed and the syntax indicating the division direction may be determined in response to the binary division CU. In this case, as a method of indicating the direction of binary division, a method of determining a split direction based on decoding a plurality of syntaxes such as binary_split_hor and binary_split_ver or decoding a syntax and a signal value thereof according to binary_split_mode, Horizontal (0) Alternatively, a method of processing division in the vertical (1) direction may be illustrated.

As another embodiment according to the present invention, the depth of a coding unit (CU) split using a binary tree may be represented using binary_depth.

See FIGS. 1 through 8 for blocks divided by the method as described with reference to FIGS. 9 and 10 (eg, coding unit (CU), prediction unit (PU), and transform unit (TU)). By applying the methods as described above, encoding and decoding on an image may be performed.

Hereinafter, other embodiments of a method of dividing a coding unit (CU) into one or more transform units (TUs) will be described with reference to FIGS. 11 through 16.

According to an embodiment of the present invention, the coding unit CU may be divided into a binary tree structure and divided into transform units (TUs) which are basic units for transforming a residual block.

For example, referring to FIG. 11, at least one of rectangular coding blocks CU ₀ and Cu ₁ divided into a binary tree structure and having a size of N × 2N or 2N × N may be divided into a binary tree structure and thus have a size of N × N. It can be divided into square transformation units (TU ₀ , TU ₁ ) having a.

As described above, the block-based image encoding method may perform prediction, transform, quantization, and entropy encoding steps.

In the prediction step, a prediction signal may be generated by referring to a block currently performing encoding and an existing coded image or a neighboring image, and thus a difference signal between the current block and the current block may be calculated.

On the other hand, in the transforming step, the difference signal is input, and the transform is performed using various transform functions. The transformed signal is classified into DC coefficients and AC coefficients and is energy compacted to improve encoding efficiency. Can be.

In addition, in the quantization step, quantization may be performed by inputting transform coefficients, and then an image may be encoded by performing entropy encoding on the quantized signal.

On the other hand, the image decoding method is performed in the reverse order of the above encoding process, the image quality distortion may occur in the quantization step.

As a method for reducing image distortion while improving encoding efficiency, the size or shape of a transform unit (TU) and the type of transform function to be applied may be varied according to the distribution of the differential signal input to the input and the characteristics of the image in the conversion step. have.

For example, in the case of finding a block similar to the current block through a block-based motion estimation process in a prediction step, a difference is measured using a cost measurement method such as a sum of absolute difference (SAD) or mean square error (MSE). The signal distribution may occur in various forms according to the characteristics of the image.

Accordingly, effective encoding can be performed by selectively determining the size or shape of the transform unit CU based on the distribution of various differential signals to perform the transform.

Referring to FIG. 12, when a differential signal is generated as shown in (a) in any coding unit CUx, the coding unit CUx is divided into a binary tree structure as shown in (b). By dividing into two transform units (TUs), an efficient transform can be performed.

For example, it can be said that the DC value generally represents an average value of the input signal, so that when a differential signal as shown in FIG. 12A is received as an input of the conversion process, two coding units CUx are provided. By dividing into transform units (TUs) it is possible to effectively represent a DC value.

Referring to FIG. 13, a square coding unit CU ₀ having a size of 2N × 2N may be divided into a binary tree structure and divided into rectangular transform units TU ₀ and TU ₁ having a size of Nx2N or 2N × N. .

According to another embodiment of the present invention, as described above, the step of dividing the coding unit (CU) into a binary tree structure may be repeated two or more times to divide the coding unit (CU) into a plurality of transform units (TUs).

Referring to FIG. 14, a rectangular coding block CB ₁ having a size of Nx2N is divided into a binary tree structure, and a block having a size of the divided NxN is further divided into a binary tree structure to N / 2xN or NxN /. After configuring a rectangular block having a size of 2, the block having a size of N / 2xN or NxN / 2 is further divided into a binary tree structure and square transform units having a size of N / 2xN / 2 (TU _1). , TU ₂ , TU ₄ , and TU ₅ ).

Referring to FIG. 15, a square coding unit CU ₀ having a size of 2N × 2N is divided into a binary tree structure, and a block having a size of Nx2N is further divided into a binary tree structure to have a square having a size of N × N. After configuring a block of, the block having the size of NxN may be divided into a binary tree structure and divided into rectangular transform units TU ₁ and TU ₂ having a size of N / 2xN.

Referring to FIG. 16, a rectangular coding unit CU ₀ having a size of 2N × N is divided into a binary tree structure, and a block having a size of the divided N × N is divided into a quad tree structure again to form N / 2 × N / 2. It can be divided into square transform units TU ₁ , TU ₂ , TU ₃ , and TU ₄ having a size.

See FIGS. 1 through 8 for blocks divided by the method as described with reference to FIGS. 11 through 16 (eg, coding unit (CU), prediction unit (PU), and transform unit (TU)). By applying the methods as described above, encoding and decoding on an image may be performed.

Hereinafter, embodiments of a method of determining, by the encoding apparatus 10 according to the present invention, a block division structure will be described.

The picture division unit 110 included in the image encoding apparatus 10 performs rate distortion optimization (RDO) according to a preset order, and thus is capable of splitting a coding unit (CU), a prediction unit (PU), and a transform as described above. The partition structure of the unit TU may be determined.

For example, to determine the block division structure, the picture division unit 110 determines the optimal block division structure in terms of bitrate and distortion while performing rate distortion optimization-quantization (RDO-Q). Can be.

Referring to FIG. 17, when the coding unit CU has a form of 2Nx2N pixel size, the 2Nx2N pixel size shown in (a), the NxN pixel size shown in (b), and the Nx2N pixel size shown in (c) , RD may be performed in the order of transform unit (PU) partition structure of 2N × N pixel size shown in (d) to determine an optimal partition structure of the transform unit PU.

Referring to FIG. 18, when the coding unit CU has a form of Nx2N or 2NxN pixel size, the pixel size of Nx2N (or 2NxN) shown in (a), the pixel size of NxN shown in (b), N / 2xN (or NxN / 2) and NxN pixel sizes shown in (c), N / 2xN / 2, N / 2xN and NxN pixel sizes shown in (d), N shown in (e) An RDO may be performed in a transform unit (PU) partition structure order of a pixel size of 2 × N to determine an optimal partition structure of the transform unit PU.

In the above, the block division method of the present invention has been described with an example in which a block division structure is determined by performing RDO (Rate distortion Optimization). However, the picture division unit 110 may have a sum of absolute difference (SAD) or mean square error (MSE). ) Can be used to determine the block division structure to reduce the complexity and maintain the proper efficiency.

According to an embodiment of the present invention, whether to apply adaptive loop filtering (ALF) in units of a coding unit (CU), a prediction unit (PU), or a transform unit (TU) divided as described above may be determined. Can be.

For example, whether the adaptive loop filter (ALF) is applied may be determined in units of a coding unit (CU), and the size or coefficient of the loop filter to be applied may vary according to the coding unit (CU).

In this case, information indicating whether to apply the adaptive loop filter (ALF) for each coding unit (CU) may be included in each slice header.

In the case of a chrominance signal, whether the adaptive loop filter (ALF) is applied in units of pictures may be determined, and the loop filter may have a rectangular shape unlike luminance.

In addition, the adaptive loop filtering (ALF) may determine whether to apply to each slice. Therefore, information indicating whether adaptive loop filtering (ALF) is applied to the current slice may be included in a slice header or a picture header.

Indicating that the adaptive loop filtering is applied to the current slice, the slice header or the picture header may additionally include information indicating the filter length in the horizontal and / or vertical direction of the luminance component used in the adaptive loop filtering process.

The slice header or the picture header may include information indicating the number of filter sets. When the number of filter sets is two or more, the filter coefficients may be encoded using a prediction method.

Accordingly, the slice header or the picture header may include information indicating whether filter coefficients are encoded by a prediction method, or may include predicted filter coefficients when the prediction method is used.

Meanwhile, not only the luminance but also the chrominance components may be adaptively filtered. In this case, information indicating whether each of the chrominance components is filtered may be included in the slice header or the picture header. It may be joint coded (ie, multiplexed coding) together with information indicating whether to filter.

In this case, in the case of chrominance components, it is most likely not to filter both Cr and Cb to reduce the complexity, so that entropy coding is performed by allocating the smallest index when not filtering both Cr and Cb. can do.

In the case of filtering both Cr and Cb, entropy encoding may be performed by allocating the largest index.

19 to 21 are diagrams for describing a composite partition structure according to another embodiment of the present invention.

Meanwhile, referring to FIG. 19, as the coding unit CU is divided into a binary tree structure, the horizontal length W as shown in FIG. 19A is longer than the vertical length H, and as shown in FIG. 19B. The shape of the coding unit CU divided into a rectangle having a vertical length H longer than the horizontal length W may appear. As described above, in the case of a coding unit having a long length in a specific direction, it is highly likely that coding information is concentrated in the left, right, and top and bottom edge regions relatively to the middle region.

Therefore, in order to encode and decode more precisely and efficiently, the encoding apparatus 10 according to an embodiment of the present invention easily divides an edge region of a coding unit having a long length in a specific direction by quad tree and binary tree splitting. The coding unit can be divided into a ternary tree or triple tree structure that can be split.

For example, FIG. 19A illustrates a first region of a left edge having a horizontal W / 8 and a vertical H / 4 length, and a horizontal W / 8 * 6 and vertical when the splitting target coding unit is a horizontally divided coding unit. As H / 4 length, it is shown that it can be divided into the 2nd area | region which is an intermediate area | region, and the 3rd area | region of the right edge of the horizontal W / 8 and the vertical H / 4 length.

19 (B) shows the first region of the upper edge of the horizontal W / 4 and the vertical H / 8 length, the horizontal W / 4 and the vertical H / 8 * when the coding unit to be divided is the vertically divided coding unit. As six lengths, it is shown that it can be divided into the 2nd area | region which is an intermediate area | region, and the 3rd area | region of the lower edge of length W / 4 and length H / 8.

In addition, the encoding apparatus 10 according to an embodiment of the present invention may process such division of the ternary tree structure through the picture division unit 110. To this end, the picture dividing unit 110 may not only determine the division into the quad tree and the binary tree structure described above according to the coding efficiency, but also determine the subdivided division method in consideration of the ternary tree structure.

Here, the division of the ternary tree structure can be processed for all coding units without any limitation. However, considering the encoding and decoding efficiency as described above, it may be desirable to allow the ternary tree structure only for the coding unit of a certain condition.

In addition, the ternary tree structure may require ternary splitting in various manners for the coding tree unit, but in consideration of encoding and decoding complexity and transmission bandwidth by signaling, it may be preferable that only an optimized predetermined form is allowed.

Accordingly, in determining the division of the current coding unit, the picture dividing unit 110 may determine and determine whether to split into a ternary tree structure of a specific type only when the current coding unit meets a preset condition. In addition, depending on the allowance of the ternary tree, the split ratio of the binary tree may also be extended and changed to 3: 1, 1: 3, etc., not just 1: 1. Accordingly, the split structure of the coding unit according to the embodiment of the present invention may include a complex tree structure divided into quadtrees, binary trees, or ternary trees according to a ratio.

20 to 22 illustrate a partition table for determining a partition of a complex tree structure according to an embodiment of the present invention. For example, the picture partition unit 110 may perform partition target coding based on the partition table. The composite partition structure of the unit can be determined.

According to an embodiment of the present disclosure, the picture division unit 110 processes quad tree division in response to a maximum size of a block (eg, pixel-based 128 x 128, 256 x 256, etc.), and quad tree division. A complex partitioning process for processing at least one of a dual tree structure and a triple tree structure partition corresponding to the terminal node may be performed.

In particular, according to an embodiment of the present invention, the picture partition unit 110 may be a first binary partition (BINARY 1) and a second binary partition (BINARY 2), which are binary tree partitions corresponding to the characteristics and sizes of the current block, according to the partition table. ) And a partition structure of any one of the first ternary partition TRI 1 and the second ternary partition TRI 2.

Here, the first binary division may correspond to a vertical or horizontal division having a ratio of N: N, and the second binary division may correspond to a vertical or horizontal division having a ratio of 3N: N or N: 3N, and each The binary partitioned root CU may be divided into CU0 and CU1 of each size specified in the partition table.

Meanwhile, the first ternary division may correspond to a vertical or horizontal division having a ratio of N: 2N: N, and the second ternary division may correspond to a vertical or horizontal division having a ratio of N: 6N: N and each The ternary divided root CU may be divided into CU0, CU1, and CU2 of each size specified in the partition table.

Accordingly, FIGS. 20 to 22 are partition tables showing respective processable partition structures and coding unit sizes in the case of division, corresponding to the sizes of the division target coding units.

However, the picture division unit 110 according to an exemplary embodiment of the present invention may include a maximum coding unit size and a minimum coding unit size for applying the first binary division, the second binary division, the first ternary division, or the second ternary division. You can set each.

This is because performing an encoding and decoding process corresponding to a block having a minimum size, for example, a horizontal or vertical pixel of 2 or less may be inefficient in terms of complexity, and thus, a partition table according to an embodiment of the present invention An allowable partition structure for each size of each coding unit may be predefined.

Accordingly, the picture dividing unit 110 may prevent a case in which the picture dividing unit 110 is divided into a minimum size, for example, a size less than 4 and the horizontal or vertical pixel size is 2, and the like, and for this purpose, the size of the target block to be divided. Determines in advance whether to allow the first binary division, the second binary division, the first ternary division, or the second ternary division, and then compares the RDO performance operations corresponding to the allowable division structure to determine an optimal division structure. Can be.

Accordingly, referring to FIG. 20, when the root coding unit CU 0 having the maximum size is binary divided, the binary division structure includes CU0 constituting any one of 1: 1, 3: 1, and 1: 3 vertical divisions. The three-part division structure may be divided into CU0, CU1, and CU2 constituting any one of 1: 2: 1 or 1: 6: 1 vertical division.

In particular, as shown in FIG. 20, according to the size of the coding target coding unit, an allowable vertical division structure may be limited. For example, the vertical division structure of the 64X64 coding unit and the 32X32 coding unit may allow all of the first binary division, the second binary division, the first ternary division, and the second ternary division, but among the vertical division structures of the 16X16 coding unit. The second ternary division may be limited to impossible. In addition, the vertical division structure of the 8X8 coding unit may be limited to allow only the first binary division. Thus, splitting into blocks of a minimum size that causes complexity can be prevented in advance.

Similarly, referring to FIG. 21, when the root coding unit CU 0 of the maximum size is binary divided, the binary division structure constitutes one of 1: 1, 3: 1, or 1: 3 horizontal division. The ternary division structure may be divided into CU0, CU1 and CU2 constituting any one of 1: 2: 1 or 1: 6: 1 horizontal division.

Likewise, as shown in FIG. 21, according to the size of the coding target coding unit, an allowable horizontal division structure may be limited. For example, the horizontal division structure of the 64X64 coding unit and the 32X32 coding unit may allow all of the first binary division, the second binary division, the first ternary division, and the second ternary division, but among the horizontal division structures of the 16X16 coding unit. The second ternary division may be limited to impossible. In addition, the horizontal division structure of the 8X8 coding unit may be limited to only the first binary division. Thus, splitting into blocks of a minimum size that causes complexity can be prevented in advance.

Meanwhile, FIG. 22 is a diagram illustrating a division form when the horizontal division corresponding to the coding unit vertically divided is processed.

Referring to FIG. 22, the picture division unit 110 horizontally processes a vertically divided coding unit into a first binary division or a second binary division or horizontally processes a first ternary division or a second ternary division according to a division table. Can be split.

For example, in response to the coding unit vertically divided into 32X64, the picture division unit 110 divides the CU0 and CU1 of 32X32 according to the first binary division, or the C0 and CU1 of 32X48 and 32X16 according to the second binary division. Or divided into 32X32, 32X16, and 32X16 CU0, CU1, and CU2 according to the first ternary division, or divided into 32X8, 64X48, and 32X8, CU0, CU1, and CU2, according to the second ternary division.

In addition, the picture division unit 110 may vertically divide the horizontally divided coding unit into the first binary division or the second binary division, or vertically divide the horizontal division coding unit into the first ternary division or the second ternary division.

For example, in response to a coding unit horizontally divided into 32X16, the picture division unit 110 divides the CU0 and the CU1 of 16X16 according to the first binary division, or the C0 and CU1 of 24X16 8X16 according to the second binary division. The image may be divided into CU0, CU1, and CU2 of 8X16, 16X16, and 8X16 according to the first ternary division, or CU0, CU1, and CU2 of 4X16, 24X16, and 4X16, according to the second ternary division.

The division allowance structure may be conditionally determined differently according to the size of the CTU, the CTU group unit and the slice unit, and in the vertical and horizontal directions, such as: first binary division, second binary division, first ternary division, and second ternary division Each CU partition ratio and decision size information in the case of processing may be defined by a partition table, or condition information may be set in advance.

This complex division process will be described in more detail with reference to FIG. 23.

Referring to FIG. 23, the encoding apparatus 10 according to an embodiment of the present invention may process the above-described complex partitioning through the picture partitioning unit 110 and signal the corresponding partitioning information using the SPLIT_MODE information. have.

To this end, the encoding apparatus 10 enters a block division and partition processing process of the picture division unit 110 (S1001), and activates a split mode SPLIT_MODE parsing for complex division (S1003).

Accordingly, when the SPLIT_MODE information indicating the split information is parsed according to a predefined condition (S1005), the encoding apparatus 10 determines whether the SPLIT_MODE information is NO_SPLIT and whether the SPLIT_MODE information is NO_SPLIT. It is determined whether the size corresponds to the minimum CU size (S1007).

When the SPLIT_MODE information is NO_SPLIT or corresponds to the minimum CU size, the encoding apparatus 10 processes prediction encoding of block information without processing subsequent divisions (S1011).

On the other hand, if the SPLIT_MODE information is not NO_SPLIT and does not correspond to the minimum CU size, the encoding apparatus 10 processes adaptive complex partitioning based on the aforementioned partition table (S1009).

For example, the picture division unit 110 of the encoding apparatus 10 may be divided into any one of ROOT division, vertical or horizontal BI_VER1 division, BI_VER2 division, TRI_VER1 division, or TRI_VER2 division according to CU size and SPLIT_MODE information. Accordingly, the division process of any one of quad tree division, vertical binary division, vertical ternary division, horizontal binary division, and horizontal ternary division may be processed.

According to such a division process, by conditionally allowing the subdivided division using the binary tree and the ternary tree, it is possible to divide the ratio appropriate to the characteristics of the coding unit, thereby improving the coding efficiency.

Meanwhile, as the block division structure according to the embodiment of the present invention is complexed and diversified, the motion compensation encoding and decoding process according to the embodiment of the present invention also performs selective encoding and decoding corresponding to the main block and the sub block for accurate prediction. Process may be included.

To this end, the motion compensation predictor 240 according to an embodiment of the present invention, as shown in FIG. 23, the main block motion compensation decoder 2410, the sub block motion compensation determiner 2420, and the sub block motion. The processor may further include a compensation processor 2430.

First, the main block motion compensation decoder 2410 may perform coding unit based motion compensation prediction processing of the motion compensation predictor 240 described above according to an embodiment of the present invention. Here, the motion prediction mode used for the main block motion compensation may include the above-described merge mode, AMVP mode, or skip mode.

Then, the sub block motion compensation determiner 2420 determines whether to perform the precise motion prediction corresponding to the sub block unit subdivided from the main block. To this end, the sub-block motion compensation determiner 2420 may determine whether to perform sub-block motion compensation by using motion compensation decoding information that is previously decoded from the main block motion compensation decoder 2410.

That is, the main block motion compensation decoder 2410 outputs at least one of reference picture information, motion parameter information, or motion compensation mode information obtained by motion compensation prediction decoding of the coding unit to the sub block motion compensation determiner 2420. The sub-block motion compensation determiner 2420 may use at least one of the reference picture information, motion parameter information, or motion compensation mode information to determine whether to compensate for the sub block corresponding to the main block and the sub block. In this case, the subblock motion compensation mode corresponding to the determined subblock may be conditionally selected.

Accordingly, the subblock motion compensation processor 2430 may operate the determined subblock and each motion compensation processor corresponding to the subblock motion compensation mode to process refined motion compensation prediction corresponding to the subblock.

Here, the sub-block motion compensation mode, for example, FRUC (FRAME RATE UP-CONVERSION) mode, BIO (BI-DIRECTIONAL OPTICAL FLOW) mode, AMP (AFFINE MOTION PREDICTION) mode, OBMC (OVERLAPPED BLOCK MOTION COMPENSATION) mode, DMVR (DECODER-SIDE MOTION VECTOR REFINEMENT) mode, alternative temporal motion vector prediction (ATMVP) mode, spatial-temporal motion vector prediction (STMVP) mode, and Local Illumination Compensation (LIC) mode. It may be determined block adaptively according to the condition.

In particular, according to an embodiment of the present invention, as a precision motion compensation prediction processing unit, the sub-block motion compensation determining unit 2420 may include an affine motion compensation processing unit or an OBMC (OVERLAPPED BLOCK MOTION COMPENSATION) processing unit. .

In particular, the OBMC processor is a processor that processes additional motion compensation corresponding to an area where the inter-frame motion information overlaps, and adaptively selects the overlapped block motion compensation and the existing block motion compensation to restore the motion of each block. To handle the process. In addition, the OBMC process may include a process of weighting and correcting the reference pixels acquired using the motion information spatially adjacent to the reference pixels acquired using the motion information of the current block with respect to some pixels of the current block. . Such processing of the OBMC is to be selectively and adaptively processed due to the reduction in the compression bit rate and the increase in complexity due to the transmission of additional information. Accordingly, the OBMC is an overlapping area having pixels above a certain threshold (THRESHOLD), and has a specific characteristic. Only applicable for

In addition, the OBMC processor according to an embodiment of the present invention can process each such adaptive OBMC motion compensation process only for a predetermined subblock unit, thereby improving its encoding and decoding efficiency and compression rate.

To this end, the sub-block motion compensation determiner 2420 may determine whether to apply the OBMC motion compensation mode of the sub-block and the sub-block in one or more ways.

As a first embodiment, the sub-block motion compensation determiner 2420 may determine the sub-block and the motion compensation mode of the sub-block by parsing the signaled sub-block information and the flag information corresponding to the block currently performing decoding. have.

For example, the sub block identification information and the motion compensation mode flag information of the sub block may be signaled through a CTU header corresponding to a CTU unit. In addition, whether or not a subblock and motion compensation mode flag information may be signaled in coding unit header information corresponding to the coding unit. Accordingly, the sub block motion compensation determiner 2420 may determine the sub block and the motion compensation mode of the sub block by parsing the CTU header decoded by the main block motion compensation decoder 2410 or header information for each block. .

As a second embodiment, the sub-block motion compensation determiner 2420 may determine a motion compensation mode of the sub-block and the sub-block by using motion parameter information of the block currently performing decoding and the neighboring block. To this end, the sub block motion compensation determiner 2420 may transfer the motion parameter information of the current block from the main block motion compensation decoder 2410 to the sub block motion compensation determiner 2420.

As a third embodiment, the sub-block motion compensation determiner 2420 uses the block characteristics (block size and depth) and partition information (division direction and partition method) for performing current decoding to determine the sub-block and the sub-block. The motion compensation mode may be determined. To this end, the sub block motion compensation determiner 2420 may transfer the block characteristics and the partition information of the current block from the main block motion compensation decoder 2410 to the sub block motion compensation determiner 2420.

As a fourth embodiment, the sub-block motion compensation determiner 2420 may inherit the sub-block motion compensation mode from the upper block. For example, the sub-block motion compensation determiner 2420 is an upper block of the partitioned block when the current decoding block is a partitioned block. For example, the sub block motion compensation determiner 2420 may perform motion compensation in units of a sub block from a root block or a CTU block. Can inherit mode information. To this end, the sub-block motion compensation determiner 2420 obtains sub-block motion compensation mode information corresponding to the higher block from the main block motion compensation decoder 2410 and inherits the current block, thereby subblocking. And a motion compensation mode of the sub block.

As a fifth embodiment, the sub-block motion compensation determiner 2420 may group some of the sub-blocks of the block currently being decoded based on the motion information, and in response to the grouping area, the sub-block motion compensation determiner 2420 may perform the partial motion compensation mode. You can also decide. In this case, the sub-block motion compensation mode corresponding to the appropriate region may be determined without determining individual sub-blocks, and the sub-block motion compensation may be processed accordingly.

On the other hand, the sub-block motion compensation determiner 2420, based on the partition structure information, in the case of a block in which the binary tree structure and the ternary tree structure described above are combined with the current block, corresponding to the ternary tree structure condition of a specific ratio, Sub-block motion compensation may be selectively determined.

For example, as shown in FIGS. 19 and 20, the sub-block motion compensation determiner 2420 is divided when TRI_VER2 horizontal division or TRI_VER2 vertical division has a ternary tree structure of 1: 6: 1. The edge left and right boundary region blocks or the upper and lower edge boundary region blocks may be determined as sub blocks, and an OBMC motion compensation mode suitable for the boundary regions may be determined.

25 is a flowchart illustrating an adaptive subblock motion compensation process based on subblock size and partition information.

Referring to FIG. 25, the sub block motion compensation determiner 2420 identifies sub block size information of a block decoded by the main block motion compensation decoder 2410 (S2001).

The sub block motion compensation determiner 2420 identifies block partitioning information corresponding to the sub block size (S2003).

Thereafter, the subblock motion compensation determiner 2420 determines a subblock motion compensation mode according to the condition information (S2005).

As described above, the sub-block motion compensation determiner 2420 may process the adaptive condition determination according to the block size and the partition information, and determine the motion compensation mode of the corresponding sub-block.

As described above, the sub-block motion compensation determiner 2420 according to an exemplary embodiment of the present invention has a strikeout structure of 1: 6: 1 when the size of the subblock is greater than or equal to the minimum size and less than or equal to the maximum size. In the case of TRI_VER2 horizontal division or TRI_VER2 vertical division having a tree structure, the divided edge left and right boundary region blocks or edge upper and lower boundary region blocks may be determined as sub blocks, and an OBMC motion compensation mode suitable for the boundary region may be determined.

Thereafter, according to the determined subblock motion compensation mode, the subblock motion compensation processing unit 2430 performs an adaptive subblock motion compensation process (S2007).

FIG. 26 is a flowchart illustrating a filtering process of a decoding apparatus according to an embodiment of the present invention, and FIG. 27 is a diagram illustrating an adaptive filter application according to an embodiment of the present invention.

Referring to FIG. 26, when adaptive motion compensation of a main block and a sub block is performed (S3005) according to an embodiment of the present disclosure, the decoding apparatus 20 determines an in-loop filtering target through the post processor 250. (S3007).

Then, based on the in-loop filtering target determined according to the main block and sub block information, the post processor 250 performs the first block boundary filtering (S3009), performs the second block boundary filtering (S3011), and then. Block internal filtering is performed (S3013). Here, the first block may correspond to a horizontally adjacent block, and the second block may correspond to a vertically adjacent block.

Accordingly, the post-processor 250 may perform adaptive deblocking processing corresponding to the boundary region by adaptively sub-blocking the in-loop filtering using the above-described deblocking filter or various other low-band filters. .

As described above, referring to FIG. 26, when performing motion compensation and in-loop filtering on a block boundary region with respect to a current block according to an embodiment of the present invention, a part of a boundary region of a block using OBMC for the current block is performed. In the case where the motion compensation is performed by overlapping the pixels, in-loop filtering may be adaptively performed.

In this case, when motion compensation is performed by overlapping some pixels of the boundary area of the block using the OBMC, whether the OBMC is applied to the corresponding area is reflected in the in-loop filtering step to determine the strength of the filtering. It can be used to adjust or determine whether to perform filtering.

In addition, referring to FIGS. 23 and 25 by extending the embodiment, according to an embodiment of the present invention, the current block performs motion compensation in units of sub-blocks, and OBMC is performed at the boundary of the sub-blocks. Even when motion compensation is performed by overlapping in the boundary pixel region, this information may be referred to in applying in-loop filtering at the boundary of the sub-block.

More specifically, referring to FIG. 27, FIG. 27 shows that block adaptive deblocking filter processing corresponding to each sub-block region is performed corresponding to a coding unit CU that is a main block according to an embodiment of the present invention.

As illustrated in FIG. 27, when the adaptive motion compensation of the subblock is processed, the post-processing unit 250 of the decoding apparatus 20 may select the first subblocks corresponding to the boundary area with the first block α. The boundary region may be determined, and the first block boundary region filtering corresponding to the first boundary region may be partially performed.

In addition, the post-processing unit 250 determines subblocks corresponding to the boundary area with the second block β as the second boundary area, and partially performs filtering of the second block boundary area corresponding to the second boundary area. can do.

The post processor 250 may perform an internal filtering process on the remaining inner regions of the current coding block subjected to the boundary filtering.

Accordingly, adjacent regions of the block boundary may be subdivided into sub-block units having a size of 4 × 4, for example, and as the split ratio of the sub-block units is structured in a binary tree and a ternary tree, a variety of forms may be obtained. Block boundary filtering becomes possible.

28 to 29 illustrate signaling of the above-described block partition information, signaling to the sub-block motion compensation determiner 2420, and determination of a boundary region processed by the post processor 250 according to an embodiment of the present invention. And header information for signaling whether to apply adaptive filtering.

As illustrated in FIG. 28, the signaling header information described in FIG. 29 may be transmitted corresponding to a CTU unit, a CTU group unit determined according to motion information, or a slice unit.

Accordingly, the decoding apparatus 20 may obtain split tree list information from the CTU header information, determine whether to apply the subblock adaptive deblocking filter, determine the boundary region, or compensate for the motion of the subblock. Flag information for determining whether to apply can be obtained.

In addition, the decoding apparatus 20 may determine split sub-depth information for determining whether to block a subblock from CU header information and whether to apply a subblock adaptive deblocking filter corresponding thereto, determine a boundary region, or apply an OBMC. Flag information for determining whether or not may be obtained.

Accordingly, the encoding apparatus 10 and the decoding apparatus 20 according to an embodiment of the present invention may adaptively process motion compensation based on a complex partition tree structure in sub-block units, and thus, an efficient operation of the OBMC and By processing the adaptive filtering linked to this, it is possible to maximize encoding and decoding efficiency and transmission efficiency.

The method according to the present invention described above may be stored in a computer-readable recording medium that is produced as a program for execution on a computer, and examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape , Floppy disks, optical data storage devices, and the like, and also include those implemented in the form of carrier waves (eg, transmission over the Internet).

The computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the method can be easily inferred by programmers in the art to which the present invention belongs.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Claims (11)

In the video decoding method,
A picture of an image is divided into a plurality of coding units, which are basic units on which inter prediction or intra prediction is performed, and a quad tree of the picture or the split coding unit. Determining a target block for decoding a coding unit divided into a binary tree or a ternery tree structure; And
Adaptively determining a subblock motion compensation mode corresponding to the subblock of the target block based on the split information of the target block;
Image Decoding Method. The method of claim 1,
The ternary tree structure is determined when the higher coding unit is a horizontal division or a vertical division coding unit.
Image Decoding Method. The method of claim 1,
The ternary tree structure may include a first region of a left edge having a horizontal W / 8 and a vertical H / 4 length and a horizontal W / 8 * when the higher coding unit is horizontally divided and is a coding unit having horizontal W and vertical H lengths. 6, longitudinal H / 4 length, comprising a tree structure triangulated into a second region that is an intermediate region and a third region of the right edge of the horizontal W / 8, vertical H / 4 length;
Image Decoding Method. The method of claim 1,
The determining step,
Parsing signaled sub block information and flag information corresponding to the target block, and determining a motion compensation mode of the sub block and the sub block.
Image Decoding Method. The method of claim 1,
The determining step,
Determining a motion compensation mode of the sub block and the sub block by using the motion information of the target block and the neighboring block;
Image Decoding Method. The method of claim 1,
On the basis of the partitioning information, when the target block is divided into a ternary tree structure having a specific ratio, at least one of the blocks divided into the ternary tree structure is determined as the sub block, and the motion compensation mode of the sub block is determined. doing
Image Decoding Method. The method of claim 6,
The motion compensation mode of the subblock includes an OMBC (VERLAPPED BLOCK MOTION COMPENSATION) mode that is adaptively determined corresponding to the subblock.
Image Decoding Method. The method of claim 1,
Processing sub block motion compensation according to the sub block motion compensation mode;
Image Decoding Method. The method of claim 1,
In response to processing of the sub-block motion compensation mode, further comprising in-block filtering sub-block adaptively
Image Decoding Method. In the video decoding apparatus,
A picture of an image is divided into a plurality of coding units, which are basic units on which inter prediction or intra prediction is performed, and a quad tree of the picture or the split coding unit. A division unit for determining a target block for decoding a coding unit divided into a binary tree or a ternery tree structure; And
A subblock motion compensation determiner configured to adaptively determine a subblock motion compensation mode corresponding to the subblock of the target block based on the split information of the target block;
Video decoding device. In the video encoding method,
A picture of an image is divided into a plurality of coding units, which are basic units on which inter prediction or intra prediction is performed, and a quad tree of the picture or the split coding unit. Determining a target block for decoding a coding unit divided into a binary tree or a ternery tree structure; And
Adaptively determining a subblock motion compensation mode corresponding to the subblock of the target block based on the split information of the target block;
Image coding method.

Images