Method to induce a fusion candidate block and device that uses the same

ES 2 602 201 A2

DESCRIPTION

METHOD TO INDUCE A CANDIDATE MERGER BLOCK AND DEVICE USING THE

SAME

Technique field

The present invention relates to a video encoding and decoding method and, more particularly, to a method of obtaining a fusion candidate block and to an apparatus using the same.

Previous technique

Recently, the demand for high-quality, high-resolution video such as high-definition (HD) video and ultra-high-definition (UHD) video has increased in various fields of communication. app. As the resolution and quality of video become higher, the amount of video increases relatively compared to an existing video and therefore in a case where, when the video is transmitted using a medium such as a wireless broadband network or an existing wire or is stored in an existing storage medium, the transmission cost and the storage cost would be increased. In order to solve these problems that arise as resolution and quality are getting higher, high-efficiency video compression techniques can be used.

Video compression techniques include various techniques, such as an interprediction (image) technique to predict a pixel value included in a current image from a before or after image of the current image, a intra (image) prediction to predict the pixel value included in a current image by using pixel information within the current image, and an entropy coding technique to assign a shorter code to a high-occurrence frequency value and assign a longer code to a low-occurrence frequency value, and the video data can be effectively compressed for transmission or storage by using such a video compression technique.

Object of the invention

The first purpose of the present invention is the provision of a method of obtaining a fusion candidate with parallel processing.

The second purpose of the present invention is the provision of an apparatus for performing a method of obtaining a fusion candidate with parallel processing.

Description of the invention

According to one aspect of the present invention to achieve the first objective of the present invention described above, a method of obtaining a fusion candidate is provided. The method may include decoding information in relation to the motion estimation region (MER); determining whether a predicted block and a spatial fusion candidate block are included in the same MER; and deciding that the spatial fusion candidate block is a fusion candidate block not available if a fusion candidate block is being determined that does not use the spatial fusion candidate block when the predicted block and the spatial fusion candidate block are included in the same MER. The method may further include adaptively determining a candidate spatial fusion block according to the size of the MER and the size of the predicted block if the predicted block and the candidate spatial fusion block are included in the same MER. If the size of the MER is 8 x 8 and the size of the predicted block is 8 x 4 or 4 x 8, at least one of the candidate spatial fusion blocks of the predicted block can be replaced with a block that includes a point that is outside the MER. The method may further include determining whether the spatial fusion candidate block is included in a MER that has not yet been decoded. The method may further include replacing the spatial fusion candidate block with a block included in another MER if the predicted block and the spatial fusion candidate block are included in the same MER. The substituted spatial fusion candidate block may be a spatial fusion candidate block that is adaptively substituted to be included in a different MER from the predicted block according to a location of the spatial fusion candidate block included in the same MER. The information regarding the MER may be information regarding the size of the MER and transmitted in one unit of a picture. Determining whether the prediction target block and the spatial fusion candidate block are included in the same MER may include determining whether the prediction target block and the spatial fusion candidate block are included in the same MER according to a Determination equation based on predicted block location information, spatial fusion candidate block location information, and MER size information.

According to another aspect of the present invention to achieve the second objective of the present invention described above, a decoding apparatus is provided

ES 2 602 201 A2 of images. The apparatus may include an entropy decoding unit for decoding information in relation to the motion estimation line (MER) and a prediction unit for determining whether a prediction object block and a spatial fusion candidate block are included therein. MER and the decision of the spatial fusion candidate block as a fusion candidate block not available if the predicted block and the spatial fusion candidate block are included in the same MER. The prediction unit may be a prediction unit that adaptively determines a spatial fusion candidate block according to the size of the MER and the size of the predicted block if the predicted block and the spatial fusion candidate block they are included in the same MER. If the size of the MER is 8 x 8 and the size of the predicted block is 8 x 4 or 4 x 8, the prediction unit can replace at least one of the candidate spatial fusion blocks of the predicted block with a block that includes a point that is outside the MER. The prediction unit can determine whether the spatial fusion candidate block is included in a MER that has yet been decoded. The prediction unit may be a prediction unit that replaces the spatial fusion candidate block with a block included in another MER when the predicted block and the spatial fusion candidate block are included in the same MER. The substituted spatial fusion candidate block may be a spatial fusion candidate block that is adaptively substituted to be included in a MER different from the predicted block according to a location of the spatial fusion candidate block included in the same MER. The information regarding the MER may be information regarding the size of the MER, and be transmitted in one unit of a picture. The prediction unit may be a prediction unit that determines whether the predicted block and the spatial fusion candidate block are included in the same MER based on a determination equation according to location information of the predicted block, information location of the candidate spatial fusion block, and size information of the MER.

Advantageous effects

According to a fusion candidate block obtaining method and an apparatus using the same as described in exemplary embodiments of the present invention, parallel processing can be achieved by performing the candidate block obtaining method merge in parallel, therefore, the computational quality and implementation complexity can be reduced.

Brief description of the drawings

FIG. 1 is a block diagram illustrating a video encoder in accordance with an exemplary embodiment of the present invention.

FIG. 2 is a block diagram illustrating a video decoder in accordance with another exemplary embodiment of the present invention.

Figure 3 is a conceptual view illustrating candidate blocks for applying a blending mode and a skip mode in accordance with an exemplary embodiment of the present invention.

FIG. 4 is a conceptual view illustrating a merge candidate block decision method in accordance with an exemplary embodiment of the present invention.

FIG. 5 is a conceptual view illustrating a fusion candidate block decision method according to the size of a MER in accordance with an exemplary embodiment of the present invention.

Figure 6 is a conceptual view illustrating a method of determining whether a spatial merge candidate block of a current block is available.

FIG. 7 is a flow chart illustrating a method of obtaining a candidate spatial fusion block in a fusion mode in accordance with an exemplary embodiment of the present invention.

FIG. 8 is a flow chart illustrating an Interprediction method applying a blending mode in accordance with an exemplary embodiment of the present invention.

Detailed description of one mode of the invention

Although various modifications and exemplary embodiments may be made, only particular exemplary embodiments will be more fully described herein with reference to the accompanying drawings. However, the present invention should not be construed as limited to only the exemplary embodiments set forth herein but rather should be understood to cover all modifications, equivalents, or alternatives that fall within the scope and technical expressions. of the invention. Like numbers refer to like items throughout the drawings.

It will be understood that, even though the expressions first, second, etc. may be used herein to describe various items, these items should not be limited by these terms. These expressions are only used to distinguish one element from another. These expressions

ES 2 602 201 A2 are only used to distinguish one element from another element. For example, a first element could be called a second element without departing from the teachings of the present invention, and similarly, the second element could be called the first element. The term "and / or" includes a combination of a plurality of associated numbered items or any of the plurality of associated numbered items.

It will be understood that when one feature or element is referred to as being "connected" or "coupled" with another feature or element, it may be directly connected or coupled with the other item or intermediate elements may be present. In contrast, when referring to a feature or element as being "directly connected" or "directly coupled" with another element, it will be understood that there are no intermediate elements present.

The terminology used herein is for the purpose of describing only particular embodiments and is not intended to be limiting of exemplary embodiments of the invention. The singular forms "a", "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", or "includes", when used herein, will be understood to specify the presence of indicated characteristics, integers, steps, operations, elements, components, or any combinations thereof, but do not exclude the presence or addition of one or more other characteristics, integers, stages, operations, elements, components, or any combinations thereof.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the same reference numerals are used throughout the drawings to refer to the same parts and a repetitive explanation of the same parts will be omitted.

FIG. 1 is a block diagram illustrating a video encoder in accordance with an exemplary embodiment of the present invention.

Referring to Figure 1, a video encoder 100 may include an image partitioning module 110, an inter-prediction module 120, an intra-prediction module 125, a transform module 130, a quantization module 135, a reordering module 160, an entropy encoding module 165, a dequantization module 140, an inverse transform module 145, a filtering module 150, and a memory 155.

Each module shown in figure 1 is illustrated independently in order to provide different functional characteristics in the video encoder and is not intended to mean that each module is configured as a component unit of software or hardware. Independent. That is, each module is listed as a respective element for illustrative purposes, and at least two modules from among the modules can be combined to give one element or one module can be divided into a plurality of elements to perform a function, and one embodiment in that the respective modules are combined or divided is within the scope of the claims of the present invention without departing from the essence of the present invention.

Also, an element part cannot be an indispensable element to perform an essential function in the present invention but merely a selective element to improve performance. The present invention can be implemented with only essential elements to implement the essence of the present invention and exclude the elements that are used merely to improve performance, and a configuration that includes only the essential elements excluding the selective elements, which are used only to improve performance is also within the scope of the claims of the present invention.

Image partitioning module 110 can divide an input image into at least one processing unit. In the present case, the processing unit can be a prediction unit (PU), a transform unit (TU), or a coding unit (CU). The image partitioning module 110 can divide an image into a combination of a plurality of coding units, prediction units and transform units and can code the image by selecting a combination of a coding unit, unit or prediction units and transform unit or units based on a predetermined criterion (for example, a cost function).

For example, an image can be partitioned into a plurality of encoding units. In order to partition the coding unit, a recursive tree structure such as a quadrangular tree structure can be used, and a coding unit that is divided into other coding units with an image or a coding unit that is the largest as a root can be divided to have a child node as many times as the number of coding units divided. An encoding unit that is no longer divided according to a certain constraint becomes a leaf node. In other words, when it is assumed that only one subdivision into square partitions is available for a coding unit, a coding unit can be divided into up to four different coding units.

ES 2 602 201 A2

Hereinafter, in exemplary embodiments of the present invention, the encoding unit may be used to refer to not only a unit for encoding but also a unit for decoding.

The prediction unit can be subdivided into partitions shaped like squares or rectangles having the same size within a coding unit.

When the prediction unit is generated to perform an intra-prediction based on the coding unit, if the coding unit is not a coding unit that is the smallest, the intra-prediction can be made without dividing into a plurality of prediction units. in an N x N unit.

The prediction module may include interprediction module 120 to perform an interprediction and intraprediction module 125 to perform an intraprediction. With respect to the prediction unit, the prediction module can determine whether the inter-prediction is performed or whether the intra-prediction is performed, and it can determine specific information (for example, an intra-prediction mode, a motion vector, an image reference, etc.) according to each prediction method. In the present case, a processing unit for performing the prediction and a processing unit for determining the prediction method and a specific detail may be different. For example, the prediction method and the prediction mode can be determined in the prediction unit and the prediction can be performed in the transform unit. A residual value (a residual block) between a generated prediction block and an original block can be input into the transform module 130. Likewise, the prediction mode information, motion vector information, and so on. that are used for prediction can be encoded in the entropy encoding module 135 along with the residual value to be transmitted to the decoder. When using a specific encoding mode, it is possible that the prediction block is not generated through the prediction module 120, 125 but the original block is encoded as it is to be transmitted to a decoder.

The inter-prediction module can predict in the prediction unit based on information from at least one image from among the before or after images for a current image. The interprediction module may include a reference image interpolation module, a motion prediction module, and a motion compensation module.

The reference image interpolation module can be provided with reference image information from memory 155 and can generate pixel information in less than a whole pixel unit from the reference image. In the case of a luma pixel, a DCT-based 8-element storage interpolation filter can be used in which a filter coefficient is made to vary to generate pixel information less than the entire pixel unit in a unit of 1/4 of a pixel. In the case of a chroma signal, a DCT-based 4-element storage interpolation filter can be used in which a filter coefficient is made to vary to generate pixel information less than the entire pixel unit in a unit of 1/8 pixel.

The motion prediction module can perform motion prediction based on a reference image interpolated by the reference image interpolation module. For a method of obtaining the motion vector, various methods can be used such as FBMA (Full search-based Block Matching Algorithm), TSS (Three Step Search) , or NTS (New Three-Step Search Algorithm, New Three-Stage Search Algorithm). The motion vector may have a motion vector value in a unit of 1/2 or 1/4 of a pixel based on the interpolated pixel. The motion prediction module can predict a current prediction unit by varying the motion prediction method. As a motion prediction method, various methods such as a skip mode, a blend mode, or an advanced motion vector prediction (AMVP) mode can be used.

In accordance with exemplary embodiments of the present invention, when inter-predicting, the motion estimation region (MER) may be defined to perform the prediction in parallel. For example, when interpredicting using the merge mode or skip mode, it can be determined whether a prediction target block and a spatial fusion candidate block are included in the same MER, and when the prediction target block and the candidate block of spatial fusion are not included in the same MER, the candidate spatial fusion block can be determined as unavailable or a candidate fusion block can be determined by determining whether the candidate spatial fusion block is included in a MER that has not yet been decoded. Hereinafter, in exemplary embodiments of the present invention, an operation of the prediction unit when performing inter prediction is described.

The interprediction unit may generate the prediction unit based on information about reference pixels neighboring a current block, wherein the reference pixels are pixels within the current image. If a neighboring block of the current prediction unit is a block on which the interprediction is performed in such a way that the reference pixels are pixels on which the

ES 2 602 201 A2 performs the inter-prediction, the reference pixels included in the block on which the inter-prediction is made can be replaced with the reference pixels of the neighboring block on which the intra-prediction is made. In other words, when the reference pixel is not available, the reference pixels that are not available can be replaced with at least one reference pixel from the available reference pixels.

Intra-prediction can have directional prediction modes that use information about reference pixels according to a prediction direction and non-directional modes that do not use directional information when predicting. A mode for predicting information about luma samples and a mode for predicting information about chroma samples may be different. In addition, information about the intra-prediction mode that is used for luma samples or information about the predicted luma signal can be used to predict information about chroma samples.

In a case where the size of the prediction unit and the size of the transform unit are the same when the intra prediction is performed, the intra prediction can be performed on the prediction unit based on pixels existing on a left side. of the prediction unit, pixels that exist in a top left region, and pixels that exist over a top region. However, in a case where the size of the prediction unit and the size of the transform unit are different when the intra-prediction is performed, the intra-prediction can be performed by using the reference pixels based on the unit of transformed. Likewise, intra-prediction using an N x N division only with respect to the coding unit that is the smallest can be used.

In the intra prediction method, according to the prediction mode, a mode dependent intra smoothing (MDIS) filter can be applied to the reference pixel to generate the prediction block. A type of the MDIS filter that is applicable to the reference pixel may be different. In order to perform the intra-prediction, the intra-prediction mode of the current prediction unit can be predicted from the intra-prediction mode of the neighboring prediction unit to the current prediction unit. When the prediction mode of the current prediction unit is predicted by using information so that it is predicted from a neighboring prediction unit, if the intra-prediction modes of the current prediction unit and the prediction unit neighbor are the same, the information that the prediction modes of the current prediction unit and the neighbor prediction unit are the same can be transmitted using a predetermined flag information, and if the prediction modes of the current prediction unit and the neighboring prediction unit are different, the prediction mode information of the current block can be decoded by entropy coding.

Likewise, a residual block that includes residual value information that is a difference between the prediction unit on which the prediction is made based on the prediction unit that is generated in the prediction module 120, 125 and an original block of the prediction unit. The generated residual block can be fed into the transform module 130. The transform module 130 can transform the residual block that includes the residual value information from the original block and the prediction unit that is generated in the prediction module 120, 125 by using a transform method such as a cosine transform. discrete (DCT, discrete cosine transform) or a discrete sine transform (DST, discrete sine transform). It can be determined whether to apply the DCT or the DST in order to transform the residual block based on the intra-prediction mode information of the prediction unit that is used to generate the residual block.

Quantization modulus 135 can quantize values ​​transformed in a frequency domain by transform modulus 130. Depending on a block or importance of an image, a quantization parameter can be made to vary. A value output by quantization module 135 may be provided to dequantization module 140 and rearrangement module 160.

The reordering module 160 may reorder the quantized coefficient value with respect to the residual value.

The reordering module 160 can modify a coefficient of a block-shaped two-dimensional array to give a one-dimensional vector shape through a coefficient scanning method. For example, in the rearrangement module 160, from a DC coefficient to a coefficient in a high frequency domain can be scanned to rearrange as a one-dimensional vector using a diagonal scan mode. According to the size of a transform unit and the intra-prediction mode, a vertical scanning mode of scanning two-dimensional coefficients in block form in a column direction or a horizontal scanning mode of scanning two-dimensional coefficients in the block shape in a row direction can be used instead of diagonal scan mode. In other words, it can be determined which scan mode is used from among the diagonal scan mode, the vertical scan mode and the horizontal scan mode, according to the size of the transform unit and the intra-prediction mode.

ES 2 602 201 A2

Entropy encoding module 165 performs entropy encoding based on values ​​output from reordering module 160. Entropy encoding can use various encoding methods such as, for example, Exponential Golomb, Context Adaptive Binary Arithmetic Encoding ( CABAC, Context-Adaptive Binary Arithmetic Coding).

The entropy encoding unit 165 can encode various information such as encoding unit residual coefficient information and block type information, prediction mode information, partition unit information, prediction unit information, unit information. transmission information, motion vector information, reference image information, interpolation information about a block, filtering information, MER information, etc. from reordering module 160 and prediction module 120, 125.

The entropy coding unit 165 can perform entropy coding on the coefficient value in the coding unit that is input from the reordering module 160 by using the entropy coding method such as CABAC.

The dequantization module 140 and the inverse transform module 145 dequantize values ​​quantized by the quantization module 135 and inverse transforms the values ​​transformed by the transform module 130. The residual value that is generated by the dequantization module 140 and the inverse transform module 145 can be added to the prediction unit that is predicted through the motion estimation module, the motion compensation module, and the intra-prediction module. included in the prediction module 120, 125 to generate a reconstructed block.

The filtering module 150 may include at least one of a block ungrouping filter, a displacement correction module, and an adaptive loop filter (ALF).

The block ungrouping filter can remove a block distortion that is generated due to a boundary between blocks in a reconstructed image. In order to determine if block ungrouping filtering is performed, it can be determined whether to apply the block ungrouping filter to the current block based on pixels included in multiple columns or rows included in the block. When the block ungrouping filter is applied to the block, a strong filter or a weak filter can be applied depending on a required block ungrouping filtering intensity. Also, in the application of the block unbundling filter, when vertical filtering and horizontal filtering are performed, filtering in the horizontal direction and filtering in the vertical direction can be processed in parallel.

The displacement correction module can correct a displacement from an original image in one unit of pixels with respect to the image on which the block ungrouping filtering is performed. In order to perform offset correction with respect to a specific image, a method of classifying the pixels included in the image can be used to give a predetermined number of regions, determine a region over which the offset is to be performed, and applying the offset to a corresponding region or a method of applying the offset by considering the edge information of each pixel.

The Adaptive Loop Filter (ALF) can perform filtering based on a comparison of the filtered reconstructed image and the original image. After sorting the pixels included in the image to give a predetermined group and determining a filter to be applied to a corresponding group, then filtering can be applied to each predetermined group for differentially with each filter. Information about whether to apply the ALF can be transmitted by the coding unit (CU) and the size and a coefficient of the ALF to be applied can be different for each block. The ALF can have various shapes and therefore a number of coefficients in the filter can be different for each filter. Information related to ALF filtering (filter coefficient information, Active / Non-Active ALF information, filter shape information, etc.) can be included and transmitted in a predetermined set of parameters in a bit stream.

Memory 155 can store a reconstructed image or block outputted from filtering module 150, and the stored reconstructed image or block can be provided to prediction module 120, 125 when inter-prediction is performed.

FIG. 2 is a block diagram illustrating an image decoder in accordance with another exemplary embodiment of the present invention.

Referring to Figure 2, a video decoder may include an entropy decoding module 210, a reordering module 215, a dequantization module 220, a reverse transform module 225, a prediction module 230, 235, a module filter 240 and memory 245.

When a video bit stream is input from the video encoder, the input bit stream can be decoded in an order opposite to the order of processing in the video encoder.

The entropy decoding module 210 can perform entropy decoding in an opposite order of performing the entropy encoding in the entropy encoding module of the video encoder. The information to generate the prediction block from among the information

ES 2 602 201 A2 decoded by entropy decoding module 210 can be provided to prediction module 230, 235 and residual values ​​that are entropy decoded in entropy decoding module can be input into reordering module 215.

The entropy decoding module 210 can decode information regarding the intraprediction and interprediction made by the encoder. As described above, when there is a predetermined restriction for intra-prediction and inter-prediction in the video encoder, information regarding the intra-prediction and inter-prediction of the current block can be provided by performing the constraint-based entropy decoding.

The reordering module 215 can perform the reordering of the bit stream that is entropy decoded by the entropy decoding module 210 based on an encoder reordering method. The coefficients represented as a one-dimensional vector can be reconstructed and rearranged as a two-dimensional block.

Dequantization module 220 may perform dequantization based on the quantization parameter that is provided from the encoder and the reordered coefficient block.

The inverse transform module 225 can perform an inverse DCT and an inverse DST on a result of the quantization performed by the video encoder with respect to the DCT and DST performed by the transform module. The inverse transform can be performed based on the transmission unit which is determined by the video encoder. In the transform modulus of the video encoder, DCT and DST can be performed selectively according to a plurality of information such as the prediction method, the current block size and prediction direction, and the transform modulus. Inverse 225 of the video decoder can perform an inverse transform based on transform information performed in the transform module of the video encoder.

The prediction module 230, 235 may generate the prediction block based on information regarding the generation of the prediction block that is provided from the entropy decoding module 210 and information from the previously decoded image or block that is provided from memory 245.

The prediction module 230, 235 may include a prediction unit determination module, an inter-prediction module, and an intra-prediction module. The prediction unit determination module may receive various information such as prediction unit information, prediction mode information of the intra-prediction method, and information regarding the motion prediction of the inter-prediction method that is input to starting from the entropy decoder, distinguish the prediction unit in the current coding unit based on the received information, and determining whether the inter prediction is performed on the prediction unit or the intra prediction is performed on the prediction unit. The interprediction unit can perform interprediction with respect to the current prediction unit based on information included in at least one image between the previous images and subsequent images of the current image that includes the current prediction unit by using of information required for inter prediction of the current prediction unit that is provided by the video encoder.

In order to perform inter-prediction, based on the coding unit, it can be determined whether the motion prediction method in the prediction unit included in a corresponding coding unit is the skip mode, the blend mode, or the slip mode. AMVP.

According to an exemplary embodiment of the present invention, when inter-predicting, the motion estimation region (MER) can be defined to perform the prediction in parallel. For example, when interpredicting using fusion or skipping, it can be determined whether the predicted block and the spatial fusion candidate block are included in the same MER. When the predicted block and the spatial fusion candidate block are not included in the same MER, the spatial fusion candidate block can be determined as unavailable or the spatial fusion candidate block can be determined as the fusion candidate block by determining the if the candidate spatial fusion block is included in a MER that has not yet been decoded. An operation of the prediction module will be described in detail in an exemplary embodiment of the present invention.

The intra-prediction module can generate a prediction block based on pixel information within the current image. When the prediction unit is a prediction unit for performing the intra-prediction, the intra-prediction can be performed based on information of intra-prediction modes of the prediction unit that is provided by the video encoder. The intra-prediction module may include the MDIS filter, a reference pixel interpolation module, and a DC filter. The MDIS filter is a module for filtering on the reference pixel of the current block, and it can be determined whether to apply the filter and apply according to the prediction mode of the current prediction unit. Filtering can be performed on the reference pixel of the current block by using the prediction mode of the prediction unit and the MDIS filter information that is provided by the video encoder. When the prediction mode of the current block is a mode

ES 2 602 201 A2 does not perform filtering, the MDIS filter cannot be applied.

The reference pixel interpolation module can generate a reference pixel in a pixel unit less than an integer value by interpolating the reference pixel when the prediction mode of the prediction unit is the prediction unit to perform an intra prediction based on a pixel value of the interpolated reference pixel. When the prediction mode of the current prediction unit is a prediction mode that generates the prediction block without interpolating the reference pixel, the reference pixel cannot be interpolated. The DC filter can generate the prediction block through filtering if the prediction mode of the current block is a DC mode.

The reconstructed block or image may be provided to filter module 240. Filter module 240 may include a block unbundling filter, a displacement correction module, an ALF.

Information about whether the block ungrouping filter is applied to a corresponding block or picture and whether a strong filter is applied or a weak filter is applied if the block ungrouping filter is applied can be provided from the video encoder. The block ungrouping filter of the video decoder can be provided with information about the block ungrouping filter from the video encoder and perform block ungrouping filtering for the corresponding block in the video decoder. As with the video encoder, vertical block ungrouping filtering and horizontal block ungrouping filtering are performed first, while at least one of the vertical block ungrouping and horizontal block ungrouping can be performed in an overlapping area. In the overlapping area of ​​vertical block ungrouping filtering and horizontal block ungrouping filtering, vertical block ungrouping filtering or horizontal block ungrouping filtering that has not been previously performed can be performed. Through this block ungrouping filtering process, a parallel processing of the block ungrouping filtering may be possible.

The displacement correction module can perform a displacement correction on the reconstructed image based on a type of the displacement correction that is applied to the image and displacement value information.

The ALF can perform filtering based on a comparison value of the original image and the reconstructed image through filtering. The ALF can be applied to the encoding unit based on information about whether to apply the ALF, information about an ALF coefficient that is provided from the decoder. The ALF information can be included in a particular set of parameters to be provided.

Memory 245 can store the reconstructed image or block to be used as the reference image or reference block, and the reconstructed image can be provided to the output module.

As described above, although the coding unit is used to refer to a coding unit in an exemplary embodiment, the coding unit may be a unit to perform not only the coding. but also decoding. Hereinafter, a prediction method described in Figures 3-11 according to an exemplary embodiment of the present invention may be performed by an element such as the prediction module included in Figure 1 and figure 2.

FIG. 3 is a conceptual view illustrating candidate blocks for applying blending mode and skip mode in accordance with an exemplary embodiment of the present invention.

Hereinafter, for illustrative purposes, a description is made with respect to the mode of fusion in an exemplary embodiment of the present invention; however, the same method can be applied to the skip mode and such an embodiment is also within the scope of the claims in the present invention.

Referring to Figure 3, in order to perform inter-prediction through the blending mode, spatial blend candidate blocks 300, 305, 310, 315, 320 and temporal blend candidate blocks 350, 355 can be used.

When a point (xP, yP) lying on an upper left portion of the predicted block relative to a location of the predicted block, with a width of the predicted block, nPSW and a height of the predicted block , sPSH, each block of candidate spatial fusion blocks 300, 305, 310, 315, 320 can be one of a first block 300 that includes a point (xP - 1, yP + nPSH - MinPuSize), a second block 305 that includes a point (xP + nPSW - MinPuSize, yP - 1), a third block 310 that includes a point (xP + nPSW, yP - 1), a fourth block 315 that includes a point (xP - 1 , yP + nPSH), and a fifth block 320 that includes a point (xP - MinPuSize, yP - 1).

The temporary fusion candidate can use a plurality of candidate blocks and a first Col block (co-located block) 350 can be a block that includes a point (xP + nPSW, yP + nPSH) that lies on a Col image (image co-located). If the first Col 350 block does not exist or is not available (for example, if the first Col block does not perform the interprediction), you can use

ES 2 602 201 A2 a second Col 355 block that includes a point (xP + (nPSW >> 1), yP + (nPSH >> 1)) lying on the Col image instead.

According to an exemplary embodiment of the present invention, in order to perform interprediction using the parallel fusion mode when performing motion prediction, it can be determined whether to use the fusion candidate block in relation to a certain area. For example, in order to determine the fusion candidate block to perform the fusion mode, relative to a predetermined area of ​​a certain size, it can be determined whether the fusion candidate block exists within the predetermined area together with the target block. prediction to determine whether to use the merge candidate block or not, or substitute with another merge candidate block, thereby performing the prediction of movement in parallel relative to the predetermined area. Hereinafter, a parallel motion prediction method using blending mode will be described in an exemplary embodiment of the present invention.

FIG. 4 is a conceptual view illustrating a method of determining a fusion candidate block in accordance with an exemplary embodiment of the present invention.

Referring to Figure 4, it is assumed that a coding unit that is the largest (LCU) is divided into four motion estimation regions (MER).

In the case of a first PU0 prediction block included in a first MER (MER0), similar to Figure 4, when the inter prediction is performed by using the merge mode with respect to the first PU0 prediction block, there can be five spatial fusion candidate blocks 400, 405, 410, 415, 420 as the spatial fusion candidate blocks. The five merge candidate blocks 400, 405, 410, 415, 420 may exist in a location not included in the first MER (MER0) and may be blocks that have already been encoded / decoded.

The second prediction block (PUI) is a prediction block included in a second MER (MER1) and four fusion candidate blocks 430, 435, 445, 450 from among the spatial fusion candidate blocks 430, 435, 440, 445, 450 to perform inter prediction using the merge mode can be blocks that exist within the second MER (MER1) and blocks that belong to the same MER that currently performs the prediction. The remaining one fusion candidate block 440 may be a block that exists on the right side of the current MER and a block included in the LCU or MER that has not yet been encoded / decoded.

According to an exemplary embodiment of the present invention, when the merge candidate block of the current block and the current block belong to the same MER, the merge candidate block of the current block is excluded and the movement information of by at least one block in another location can be added as the merge candidate according to the current block size and the MER size.

A block that includes a point that exists in another MER in a vertical or horizontal direction can be added as the fusion candidate block. Alternatively, a block that belongs to another MER at a location that is closest to the candidate block can be added as the merge candidate block. Alternatively, a block at a predetermined location according to the shape and size of the current block can be added as a merge candidate block.

For example, in the case of the fusion candidate block 435 that is on an upper side of the second prediction unit (PU1) and the fusion candidate block 450 that is located on an upper left side of the second prediction unit, Blocks 455, 460 that include points that lie on the outside of the second MER in the vertical direction can be used as substituted fusion candidate blocks. For the fusion candidate block 430 that is on a left side of the second prediction unit and the fusion candidate block 445 that is located on a lower left side of the second prediction unit, the blocks 465, 470 that include points on the outside of the MER in the horizontal direction can be used as the substituted fusion candidate blocks. When a block is included in the same MER with the current prediction unit and therefore cannot be used as the fusion candidate block, the fusion candidate block can be replaced with another block that includes a point in another MER according to with a location of the merge candidate block.

In the case of a third prediction block (PU2), a merge candidate block 475 included in the same MER with the third prediction block can be substituted for use by a block 480, which exists on an upper side in the vertical direction. Furthermore, as another exemplary embodiment of the present invention, it is possible to substitute the location of the fusion candidate block by substituting a location of the spatial fusion candidate block with a block included in another MER in a direction other than the vertical or horizontal direction and the present exemplary embodiment is also included within the scope of the claims of the present invention.

The following steps can be performed in order to perform a method to determine the fusion candidate blocks.

1) Stage of decoding information in relation to the motion estimation region (MER)

Information regarding the MER may include information about the size of the MER.

ES 2 602 201 A2

It can be determined whether the predicted block is included in the MER based on information about the size of the MER and the size of the predicted block.

2) Step of determining whether the block object of prediction and the candidate block of spatial fusion are included in the same MER

In the case that the prediction target block and the spatial fusion candidate block are included in the same mEr, the following steps can be performed to adaptively determine the spatial fusion candidate block according to the size of the MER and the size of the predicted block.

3) Step of determining that the spatial fusion candidate block is not available when the predicted block and the spatial fusion candidate block are included in the same MER

When the predicted block and the spatial fusion candidate block are included in the same MER, the spatial fusion candidate block can be determined as unavailable and the spatial fusion candidate block included in the same MER can be replaced with another candidate block of fusion. Also, as described hereinafter, the fusion candidate block that is determined to be unavailable may not be able to be used in interprediction with the fusion mode.

According to another exemplary embodiment of the present invention, a method that does not use the fusion candidate block included in the same MER with the predicted block may be applied as well.

For example, among the candidate merge blocks, the blocks in which a MER on which an encoding / decoding has already been performed is included and if it is different from a current MER on which a prediction is currently being performed, are They are available for inter prediction applying the parallel blending mode. The blocks can be used as the interprediction candidate blocks with the merge mode. However, blocks belonging to the MER on which the prediction is currently being performed cannot be used as the candidate interprediction block for interprediction with the merge mode. The block on which the encoding / decoding is not performed cannot be used as the candidate interprediction block either. The present exemplary embodiment is also included within the scope of the claims of the present invention.

FIG. 5 is a conceptual view illustrating a method of determining a fusion candidate block based on the size of a MER in accordance with an exemplary embodiment of the present invention.

Referring to Figure 5, the fusion candidate can be adaptively determined according to the size of the MER and the size of the current prediction unit. For example, in a case where a fusion candidate that corresponds to one of the location of the fusion candidates A, B, C, D, E is included in the same MER with the current prediction unit, the candidate merge is determined to be unavailable. In the present case, the movement information of at least one block in another location can be added as the merge candidate according to the current block size and the size of the MER.

In Figure 5, the size of the MER is assumed to be 8 x 8 and the block to be predicted is 4 x 8. When the size of MER is 8 x 8, a block of A included in the block to be predicted belongs to the same MER with the block to be predicted and the blocks of B, C, D and E are included in a MER different from the block to be predicted.

In the case of the A block, the block can be substituted with a one-block location (eg, the A 'block) that is included in the different MER. Therefore, in accordance with an exemplary embodiment of the present invention, when the merge candidate block of the current block and the current block belong to the same MER, the current block merge candidate block can be excluded from a block. for merge candidate such that the movement information of at least one block in another location can be added as the merge candidate according to the current block size and MER size.

According to an exemplary embodiment of the present invention, the MER size information may be included in a higher level syntax information to be transmitted.

Table 1 hereinafter is associated with a method of transmitting the size information about the MER in the top-level syntax.

<Table 1>

ES 2 602 201 A2

<td>pic pitraiiieU'i_ser_itwp () {</td><td>Descriptor</td>

<td>p fc_ para ni et € r_ «t_ id</td><td>eu (v)</td>

<td>seq pa ra hj eter_sct_fd</td><td>eu (v)</td>

<td>in tropy _cod ingmod eflap</td><td>u (l)</td>

<td>niiin_ieiii]) oral_laj ersHiTcliingpoiniflags</td><td>ue (Y)</td>

<td>foi (i = 0; i &lt;iiinii lemporal layer iwj [chulapoim ílflgj: i--)</td><td></td>

<td>ientporaMayer_s «irching_point_flag [i]</td><td>u (l)</td>

<td>num_ref_idx_lO_ (lefau] t_acrive_minusl</td><td>ne (v)</td>

<td>núm reí irtx ll ileíault active niinusl</td><td>eu (v)</td>

<td>pie in it qp minuslo P in relation to 26 * /</td><td>I know</td>

<td>eo n st ra ín ed _in tra _ p red _ fia g</td><td>u (l)</td>

<td>shared pps info enabled flag</td><td>u (l)</td>

<td>if (hai ed pps info enibled flag)</td><td></td>

<td>ifl¡ adapli ^ e_loop_tthei_enabled_flag)</td><td></td>

<td>a1f_pninni ()</td><td></td>

<td>iff cu_qp_delia_enabletl flag)</td><td></td>

<td>inai_cu_qp_rtelta_deplh</td><td> 11(4)</td>

<td>lo g2 _p a ral teliuergelcv el_ ni i mi s 2</td><td>ιιφ}</td>

<td>rbsp irailing bits ()</td><td></td>

<td>F</td><td></td>

Referring to Table 1, the MER size information can be obtained based on a syntax element Iog2_parallel_merge_level_m¡nus2 included in a high-level syntax structure such as a set of image parameters. A syntax element Iog2_parallel_merge_level_m¡nus2 may also be included in a high-level syntax structure other than the image parameter set, and the present exemplary embodiment is also within the scope of the claims of the present invention.

Table 2 hereinafter describes a relationship between a value of 10 Iog2_parallel_merge_level_m¡nus2 and the size of the MER.

&lt;Table 2&gt;

<td>Iog2_parallel_merge_level_m¡nus2</td><td>MER size</td><td>Observation</td>

<td> 0</td><td>4x4</td><td>Sequencing skip blending mode for all PUs in an LCU because the minimum PU size allowed by HEVC is 4 x 4</td>

<td> 1</td><td>8x8</td><td>Parallel skip merge mode search allowed for all PUs within an 8x8 block</td>

<td> 2</td><td>16x 16</td><td>Parallel skip merge mode search allowed for all PUs within a 16 x 16 block</td>

<td> 3</td><td>32 x 32</td><td>Parallel skip merge mode search allowed for all PUs within a 32 x 32 block</td>

<td> 4</td><td>64x64</td><td>Parallel skip merge mode search allowed for all PUs within a 64 x 64 block</td>

ES 2 602 201 A2

Referring to Table 2, the value of log2_parallel_merge_level_minus2 can have a value from 0 to 4, inclusive, and the size of the MER size can be specified differently according to the value of the syntax element. When the MER is 0, this is the same as performing the interprediction using the blending mode without using the MER.

The syntax element that includes the MER size information may, in an exemplary embodiment of the present invention, represented and used as the expression "MER size information syntax element" and defining the MER size information syntax element as in Table 2 is an example and it is possible to specify the MER size using various different methods and such a method of expressing syntax elements is also within the scope of the claims of the present invention.

Fig. 6 is a conceptual view illustrating a method of determining whether a spatial merge candidate block of the current block is available.

Referring to FIG. 6, based on locations of a prediction target block 600 and a spatial fusion candidate block 650 neighboring the prediction target block 600 and the MER size information syntax element, the availability of the block can be determined. spatial fusion candidate.

When (xP, yP) is assumed to be a point at the top left of the prediction block and (xN, yN) is a point at the top left of the fusion candidate block, it can be determined whether the candidate block Spatial fusion is available through the following Mathematical Expression 1 and Mathematical Expression 2.

&lt;Mathematical expression 1&gt;

(xP &gt;&gt; (Iog2_i&gt; ariilleI_merge_level_niiiius2 + 2)) == (xN »(log2_parallel_merge_level_minus2 + 2)) &lt;Mathematical expression 2&gt;

(yP »(log2_paraHel_nierge_level_niiniis2 + 2)) == (yN» (log2_p; u '; ülel_mei'ge_leYd_iiiiiius2 + 2))

Mathematical Expression 1 and Mathematical Expression 2 above are exemplary equations for determining whether the fusion candidate block and the predicted block are included in the same MER. Furthermore, it can be determined whether the fusion candidate block and the predicted block are included in the same MER by using a method other than the above determination method as long as it does not depart from the essence of the present invention.

FIG. 7 is a flow chart illustrating a method of obtaining a candidate spatial fusion block in a fusion mode in accordance with an exemplary embodiment of the present invention.

Referring to Figure 7, the information in relation to the MER is decoded (step

S700).

The information regarding the MER may be syntax item information, as described above, and may be included in the high-level syntax structure. Based on the information regarding the decoded MER, it can be determined whether the spatial fusion candidate block and the predicted block are included in the same MER or in different MERs.

It is determined whether the candidate spatial fusion block and the block to be predicted are included in the same MER (step S710).

According to an exemplary embodiment of the present invention, when the merge candidate block of the current block and the current block are included in the same MER, the merge candidate block of the current block can be excluded and the motion information of At least one different location block of the fusion candidate block can be added as a fusion candidate according to the current block size and the MER size (step S720). In accordance with another exemplary embodiment of the present invention, when a candidate spatial fusion block and the predicted block are included in the same MER, instead of using the candidate spatial fusion block included in the MER as the Fusion candidate block, a block included in another MER with another location can substitute the spatial fusion candidate block to perform inter prediction.

Also, in another exemplary embodiment, when a candidate spatial fusion block and the predicted block are included in the same MER, the candidate spatial fusion block included in the MER cannot be used as the candidate fusion block. , as described above.

When the candidate spatial fusion block and the candidate prediction block are not included in the same MER, the inter-prediction is performed based on a corresponding candidate spatial fusion block (step S730).

FIG. 8 is a flow chart illustrating an interprediction method using a blending mode in accordance with an exemplary embodiment of the present invention.

ES 2 602 201 A2

Referring to Fig. 8, Information regarding motion prediction is obtained from the spatial fusion candidate (step S800).

The spatial fusion candidate can be obtained from the neighboring prediction unit of the predicted block. In order to obtain the spatial fusion candidate, a prediction unit width and height information, MER information, singleMCLFlag information, and information about the partitioning location may be provided. Based on the input information above, information (availableFlagN) about the availability of the spatial fusion candidate, reference image information (refIdxL0, refIdxL1), list utilization information (predFlagL0N, predFlagL1N), and vector information of motion (mvL0N, mvL1N) can be obtained according to a location of the spatial fusion candidate. The spatial fusion candidate can be a plurality of blocks neighboring the predicted block.

In accordance with an exemplary embodiment of the present invention, the spatial fusion candidate block can be classified to give three as follows: 1) a spatial fusion candidate block that is not included in the same MER and has already been encoded or decoded, 2) a candidate spatial fusion block that is included in the same MER, and 3) a candidate spatial fusion block on which encoding and decoding have not yet been processed.

According to an exemplary embodiment of the present invention, in order to perform the interprediction in parallel in one unit of the MER, out of the candidate blocks of spatial fusion to perform the interprediction, the candidate block of fusion that is not included in the MER itself and has already been encoded or decoded can be used as the candidate spatial fusion block. Furthermore, the candidate space fusion block that replaces a location of the candidate space fusion block included in the same MER can be used as the candidate space fusion block. In other words, in accordance with an exemplary embodiment of the present invention, when the current block's merge candidate block is included in the same MER as the current block, the current block's merge candidate block is excluded and the movement information of at least one block from another location can be added as the merge candidate according to the current block size and the MER size. As described above, a method of determining the fusion candidate block can be performed through a step of decoding information in relation to the MER (Motion Estimation Region), a step of determining whether the Prediction object block and fusion candidate block are included in the same MER, and a step of determining that the fusion candidate block is not available for interprediction with the fusion mode when the fusion candidate block and the predicted block are included in the same MER.

According to another exemplary embodiment of the present invention, among the candidate spatial fusion blocks to perform the interprediction, only the candidate spatial fusion block that is not included in the same MER and has already been encoded or decoded can be used to perform interprediction.

A reference image index value is obtained from the temporary merge candidate (stage

S810).

The reference image index value of the temporary merge candidate is an index value of the image Col that includes the temporary fusion candidate (Col block) and can be obtained through a particular condition as hereinafter. For example, when a point at the top left of the predicted block is (xP, yP), a width of is nPSW, and a height of the predicted block is nPSH, the reference image index value of the temporary fusion candidate can be determined as the same value as the reference image index value of the neighboring prediction unit (hereinafter referred to as " neighbor prediction unit to obtain the reference image index ”) if 1) there is the neighboring prediction unit of the block to be predicted that corresponds to a location (xP - 1, yP + nPSH - 1), 2) a partition index value of the neighboring prediction unit to obtain the reference image index is 0, 3) the neighboring prediction unit to obtain the reference image index is not a block that performs the prediction using the intra-prediction mode, and 4) the prediction object block and the neighboring prediction unit to obtain the reference image index are not included in the same MER (Motion Estimation Region). If the above conditions are not satisfied, the temporary merge candidate's reference image index value can be set to 0.

The temporary fusion candidate is determined and information regarding the motion prediction is obtained from the temporary fusion candidate (step S820).

In order to determine the temporary merge candidate block (Col block) and obtain the information regarding the motion prediction based on the determined temporary merge candidate block (Col block), a location of the Col block that is used to obtain a temporal prediction motion vector can be determined based on conditions such as, for example, whether the Col block is available to the predicted block, or where a location of the predicted block is relative to the LCU (for example, if the location of the predicted block is on a bottom boundary or a right boundary relative to the LCU). TO

ES 2 602 201 A2 through obtaining the Information regarding the motion prediction based on the determined reference image information from the Col block and the motion prediction vector information, the information regarding the motion prediction can be derived from the temporary merge candidate block (Col block).

A fusion candidate list is built (step S830).

The fusion candidate list can be constructed by including at least one of the spatial fusion candidate and the temporal fusion candidate. The spatial fusion candidate and the temporal fusion candidate included in the fusion candidate list can be arranged with a fixed priority.

The merge candidate list can be constructed by including a fixed number of merge candidates. When the fusion candidates are deficient to generate the fixed number of fusion candidates, a fusion candidate can be generated by combining the information regarding the motion prediction of the fusion candidate or the fusion candidate list can be generated. by adding a zero vector as the fusion candidate.

As described above, the above method of obtaining the fusion candidate can be used not only in the inter-frame prediction method using the fusion mode but also in the inter-frame prediction mode using the fusion mode. Omission and the present exemplary embodiment is also within the scope of the claims of the present invention.

Although the present disclosure has been described with reference to exemplary embodiments thereof, those skilled in the art will understand that various changes and modifications can be made therein without departing from the spirit and scope of the present invention. as defined by the following claims.