Abstract: Disclosed herein are a video decoding method and apparatus and a video encoding method and apparatus. Encoding and decoding of a target block are performed using intra-prediction. The intra-prediction is intra-prediction that uses bidirectional intra-prediction and a remaining mode. In bidirectional intra-prediction, a prediction value for a target pixel in the target block is determined based on reference pixels in two directions of bidirectional intra-prediction. In intra-prediction using a remaining mode, the remaining mode indicates remaining intra-prediction modes other than MPMs present in an MPM list.

Abstract: A video coding system including an acceleration device including input circuitry configured, for each of a first plurality of video frames to be encoded, to receive an input including at least one raw video frame and at least one reference frame, and to divide each of the first plurality of video frames to be encoded into a second plurality of blocks, and similarity computation circuitry configured, for each one of the first plurality of video frame to be encoded: for each the block of the second plurality of blocks, to produce an intra-prediction hint and an intra-prediction direction. Related apparatus and methods are also provided.

Abstract: Disclosed are an image encoding/decoding method and apparatus. The image decoding method includes decoding coding mode information of a current coding block, dividing the current coding block into at least one prediction block, and generating prediction samples of the at least one prediction block on the basis of the decoded coding mode, in which the coding mode information is information Indicating any one mode among intra mode, inter mode, and hybrid mode.

Abstract: A global index value is generated for selecting a global reshaping function for an input image of a relatively low dynamic range using luma codewords in the input image. Image filtering is applied to the input image to generate a filtered image. The filtered values of the filtered image provide a measure of local brightness levels in the input image. Local index values are generated for selecting specific local reshaping functions for the input image using the global index value and the filtered values of the filtered image. A reshaped image of a relatively high dynamic range is generated by reshaping the input image with the specific local reshaping functions selected using the local index values.

Abstract: An image decoding method executed by a decoding apparatus according to the present document comprises the steps of: deriving an intra prediction type for the current block from among the intra prediction types; establishing an intra prediction mode candidate list for the current block by executing a process for establishing an intra prediction mode candidate list; selecting an intra prediction mode for the current block on the basis of the intra prediction mode candidate list; and generating prediction samples for the current block on the basis of the intra prediction type and intra prediction mode.

Abstract: Given an input image in a high dynamic range (HDR) which is mapped to a second image in a second dynamic range using a reshaping function, to improve coding efficiency, a reshaping function generator may adjust the codeword range of the HDR input under certain criteria, such as for noisy HDR images with a relatively-small codeword range. An example of generating a scaler for adjusting the HDR codeword range based on the original codeword range and a metric of the percentage of edge-points in the HDR image is provided. The adjusted reshaping function allows for more efficient rate control during the compression of reshaped images.

Abstract: An image decoding method performed by a decoding apparatus according to the present disclosure includes receiving intra prediction information including at least one of most probable mode (MPM) flag information representing whether to derive an intra prediction mode for a current block based on MPM candidates for the current block or planar flag information representing whether to determine the intra prediction mode for the current block as a planar mode, deriving the intra prediction mode for the current block based on the MPM flag information and the planar flag information, deriving a predicted block for the current block based on the intra prediction mode for the current block, and generating a reconstructed picture based on the predicted block.

Abstract: A method, computer program, and computer system is provided for decoding point cloud data. Data corresponding to a point cloud is received. A number of contexts associated with the received data is reduced based on reducing a size of an array corresponding to syntax elements for predictive tree-based coding of the point cloud. The data corresponding to the point cloud is decoded based on the reduced number of contexts.

Abstract: The present invention relates to a technique for encoding and decoding video data, and more particularly, to a method for performing inter-prediction in an effective manner. The present invention combines an inter-prediction method using an AMVP mode and an inter-prediction method using a merge mode so as to propose a method for using the same candidate. The method for encoding video data proposed by the present invention comprises the following steps: receiving mode information on an inter-prediction method of a current block; determining, on the basis of the received mode information, whether the interprediction method to be applied to the current block is an AMVP mode or a merge mode; and selecting a candidate to derive motion information of the current block, wherein the candidate is selected in a left region, top region and corner region of the current block and in the same position block as the current block, and the AMVP mode and the merge mode are applied on the basis of the selected candidate.

Abstract: Aspects of the disclosure provide a method and an apparatus for video coding. In some examples, the apparatus includes processing circuitry. The processing circuitry determines, for a current block in a current picture, motion information including a first motion vector (MV) that has a x component and a y component. Each of the x and y components has a fractional MV precision that is 2?N of a sample size in the current block and has one of 2L+1 MV values with the fractional MV precision, N being 4 and indicating the fractional MV precision, and a magnitude of the first MV being represented by L bits. At least one sample of the current block is encoded based on the motion information.

Abstract: A method of data decompression includes receiving compressed pixel data substantially in raster scan order and determining a number of bits of compressed data that corresponds to one row of pixels. Then, for each group of pixels in the row, the method identifies a block-based decoding scheme for the group of pixels and decodes the group of pixels using the identified scheme.

Abstract: There is provided a method of generating a dataset of synthetic images, comprising: for each real image each depicting a real human anatomical structure: extracting and preserving a real anatomical structure region(s) from the real image, generating a synthetic image comprising a synthetic human anatomical structure region and the preserved real anatomical structure region(s), designating pairs of images, each including the real image and the synthetic image, feeding the pair into a machine learning model trained to recognize anatomical structure parts to obtain an outcome of a similarity value denoting an amount of similarity between the real image and the synthetic image, verifying that the synthetic image does not depict the real human anatomical structure when the similarity value is below a threshold, wherein an identity of the real human anatomical structure is non-determinable from the synthetic image, and including the verified synthetic image in the dataset.

Abstract: A computer-implemented method and a decompression unit for decompressing a compressed block of data in accordance with a multi-level difference table. The compressed block of data represents a block of image data comprising a plurality of image element values, wherein each level of the multi-level difference table comprises a plurality of entries. An origin value for the block of image data is determined using data representing the origin value from the compressed block of data. A level within the multi-level difference table for the block of image data is identified using an indication of the level from the compressed block of data.

Abstract: Detection of scaling of compressed videos or images is provided. A frequency domain transformation is applied along both horizontal and vertical directions of input video or images to generate frequency domain data. Statistics in the frequency domain data are computed for each of the horizontal and vertical directions to extract features. The features are modeled to scores along each of the horizontal and vertical directions. An original resolution of the input video or images in the horizontal and vertical directions is identified according to the scores.

Abstract: An apparatus of decoding video data can include a prediction mode decoding module to derive a luma intra prediction mode and a chroma intra prediction mode; a prediction size determining module to determine a size of a luma transform unit and a size of a chroma transform unit using transform size information; a reference pixel generating module to generate referential pixels if at least one reference pixel is unavailable; and a reference pixel filtering module adaptively filter the reference pixels of a current luma block based on the luma intra prediction mode and the size of the luma transform unit. The apparatus can further include a prediction block generating module to generate prediction blocks of the current luma block and the current chroma block; and a residual bock generating module to generate residual blocks of the current luma block and the current chroma block.

Abstract: Provided are method and apparatus methods and apparatuses for encoding an intra-prediction mode based on a secondary IPM. The present invention may comprises a first decision step of determining whether an intra-prediction mode of a current block is included in a first candidate mode set including M candidate modes (M is an integer equal to or greater than 1); a second decision step of determining whether the intra-prediction mode of the current block is included in a second candidate mode set including N candidate modes (N is an integer equal to or greater than 1) based on a first determination result representing a determination result of the first decision step; and an intra prediction mode encoding step of encoding the intra-prediction mode of the current block based on the first determination result or a second determination result representing a determination result of the second decision step.

Abstract: The present disclosure relates to apparatus and methods of image decoding and image encoding. In one or more embodiments, an image decoding method may comprise determining a first sample value of an upper left reference sample of the current block. The image decoding method may further comprise sequentially searching for a searched reference sample of at least one reference line from a plurality of reference lines, except for the upper left reference sample. The image decoding method may further comprise determining a second sample value of remaining reference samples of the current block, except for the upper left reference sample. The image decoding method may further comprise performing intra prediction on the current block to obtain a prediction block of the current block. The image decoding method may further comprise obtaining a residual block of the current block and a reconstruction block of the current block.

Abstract: Provided are method and apparatus methods and apparatuses for encoding an intra-prediction mode based on a secondary IPM. The present invention may comprises a first decision step of determining whether an intra-prediction mode of a current block is included in a first candidate mode set including M candidate modes (M is an integer equal to or greater than 1); a second decision step of determining whether the intra-prediction mode of the current block is included in a second candidate mode set including N candidate modes (N is an integer equal to or greater than 1) based on a first determination result representing a determination result of the first decision step; and an intra prediction mode encoding step of encoding the intra-prediction mode of the current block based on the first determination result or a second determination result representing a determination result of the second decision step.

Abstract: The present disclosure provides systems and methods for video coding. The systems include, for example, an image encoder comprising: circuitry; and a memory coupled to the circuitry, wherein the circuitry, in operation, performs the following: predicting a first block of prediction samples for a current block of a picture, wherein predicting the first block of prediction samples includes at least a prediction process with a motion vector from a different picture; padding the first block of prediction samples to form a second block of prediction samples, wherein the second block is larger than the first block; calculating at least a gradient using the second block of prediction samples; and encoding the current block using at least the calculated gradient.

Abstract: The present invention relates to an intra prediction mode mapping method and a device using the method. The intra prediction mode includes: decoding flag information providing information regarding whether an intra prediction mode of a plurality of candidate intra prediction modes for the current block is the same as the intra prediction mode for the current block, and decoding a syntax component including information regarding the intra prediction mode for the current block in order to induce the intra prediction mode for the current block if the intra prediction mode from among the plurality of candidate intra prediction modes for the current block is not the same as the intra prediction mode for the current block. Thus, it is possible to increase the efficiency with which are images are decoded.

Abstract: A three-dimensional data encoding method includes: encoding first information of a first current node or second information of a second current node, the first current node being included in an N-ary tree structure of first three-dimensional points included in a first three-dimensional point cloud, N being 2 or 4, the second current node being included in an octree structure of second three-dimensional points included in a second three-dimensional point cloud The encoding of the first information or the second information includes encoding the first information using a first encoding pattern including a pattern common to a second encoding pattern used in encoding the second information.

Abstract: A method of decoding a bitstream comprising decoding the bitstream into color values and metadata items indicating information about adaptive post-processing operations performed by a decoder, performing high dynamic range (HDR) adaptation operations on the color values based on the metadata items, and performing fixed post-processing operations to reconstruct an HDR video from the color values, wherein the HDR adaptation operations convert color values into a format expected by the fixed post-processing operations.

Abstract: A method by which a decoding device performs image decoding, according to the present invention, comprises the steps of: deriving an intra prediction mode of a current block; deriving neighboring samples including left neighboring samples and upper neighboring samples of the current block; deriving reference samples for prediction of a target sample among the neighboring samples on the basis of the position of the target sample of the current block and the prediction angle of the intra prediction mode; determining an interpolation filter for the target sample; and deriving the prediction sample of the target sample on the basis of the interpolation filter and the reference samples.

Abstract: An image encoding device (1) according to a first feature encodes blocks obtained by dividing an original image of a frame included in a video. The image encoding device (1) includes a code amount allocator (180) configured to allocate a code amount to each of a plurality of intra prediction modes defined in advance, a mode selector (171) configured to select an intra prediction mode to be applied to a target block of intra prediction from among the plurality of intra prediction modes, and an encoder (130) configured to encode identification information indicating the selected intra prediction mode in accordance with the allocated code amount. The code amount allocator (180) calculates a feature amount of a plurality of reference pixels adjacent to the target block and changes a manner of allocation of code amounts to the plurality of intra prediction modes based on the calculated feature amount.

Abstract: Provided are a video decoding method and apparatus and a video encoding method and apparatus which determine whether to use a Most Probable Mode (MPM) list, based on encoding information of a current block, obtain, from a bitstream, intra prediction mode index information indicating one of candidate intra prediction modes included in the MPM list, and determine an intra prediction mode of the current block by using the obtained intra prediction mode index information.

Abstract: An image encoder includes a processor and a memory. The memory includes instructions configured to cause the processor to perform operations. In one example implementation, the operations may include determining whether a dictionary item is available for replacing a block of an image being encoded, the determining based on a hierarchical lookup mechanism, and encoding the image along with reference information of the dictionary item in response to determining that the dictionary item is available. In one more example implementation, the operations may include performing principal component analysis (PCA) on a block to generate a corresponding projected block, the block being associated with a group of images, comparing the projected block with a corresponding threshold, descending the block recursively based on the threshold until a condition is satisfied, and identifying a left over block as a cluster upon satisfying of the condition.

Abstract: A decoding method is presented. An illumination compensation parameter is first determined for a current block of a picture. The illumination compensation parameter is determined from one or more illumination compensation parameters or from one or more reconstructed samples of at least one spatially neighbor block only in the case where said at least one spatially neighbor block belongs to the same local illumination compensation group as the current block, called current local illumination compensation group. Finally, the current block is reconstructed using the determined illumination compensation parameter.

Abstract: In some embodiments, a method selects a first template of pixels that is outside of a first block and a second template of pixels that is outside of the first block. Then, the method selects a first region of pixels that are inside the first block and a second region of pixels that are inside the first block. A first weight is calculated based on the first template of pixels and the first region of pixels and a second weight is calculated based on the second template of pixels and the second region of pixels. The first weight and the second weight are used in a motion prediction search for a second block.

Abstract: An intra prediction method and a device using the intra prediction method are provided. The intra prediction method includes the steps of: deriving a current prediction mode as a prediction mode of a current block; constructing neighboring samples of the current block with available reference samples; filtering the available reference samples; and generating predicted samples of the current block on the basis of the filtered available reference samples. The filtering step includes performing the filtering using the available reference sample located in the prediction direction of the current prediction mode and a predetermined number of available reference samples neighboring to the prediction direction of the current prediction mode.

Abstract: A method, computer program, and computer system is provided for decoding point cloud data. Data corresponding to a point cloud is received. A number of contexts associated with the received data is reduced based on reducing a size of an array corresponding to syntax elements for predictive tree-based coding of the point cloud. The data corresponding to the point cloud is decoded based on the reduced number of contexts.

Abstract: Provided are a video decoding method and apparatus and a video encoding method and apparatus which determine whether to use a Most Probable Mode (MPM) list, based on encoding information of a current block, obtain, from a bitstream, intra prediction mode index information indicating one of candidate intra prediction modes included in the MPM list, and determine an intra prediction mode of the current block by using the obtained intra prediction mode index information.

Abstract: Provided are a video decoding method and apparatus and a video encoding method and apparatus which determine whether to use a Most Probable Mode (MPM) list, based on encoding information of a current block, obtain, from a bitstream, intra prediction mode index information indicating one of candidate intra prediction modes included in the MPM list, and determine an intra prediction mode of the current block by using the obtained intra prediction mode index information.

Abstract: Provided are a video decoding method and apparatus and a video encoding method and apparatus which determine whether to use a Most Probable Mode (MPM) list, based on encoding information of a current block, obtain, from a bitstream, intra prediction mode index information indicating one of candidate intra prediction modes included in the MPM list, and determine an intra prediction mode of the current block by using the obtained intra prediction mode index information.

Abstract: Disclosed is a method of decoding an image and a method of encoding an image. The method of decoding an image includes: obtaining motion-constrained tile set information; determining, on the basis of the motion-constrained tile set information, a first boundary region of a collocated tile set within a reference picture, which corresponds to a motion-constrained tile set; padding a second boundary region corresponding to the first boundary region; and performing inter prediction on the motion-constrained tile set by using a collocated tile set that includes the padded second boundary region.

Abstract: An image signal decoding method according to the present invention comprises the steps of: decoding information indicating whether a current block is encoded using a multi-mode intra prediction; when it is determined that the current block is encoded in the multi-mode intra prediction, dividing the current block into a plurality of partial blocks; and obtaining an intra prediction mode of each of the plurality of partial blocks.

Abstract: An image signal decoding method according to the present invention comprises the steps of: decoding information indicating whether a current block is encoded using a multi-mode intra prediction; when it is determined that the current block is encoded in the multi-mode intra prediction, dividing the current block into a plurality of partial blocks; and obtaining an intra prediction mode of each of the plurality of partial blocks.

Abstract: An image decoding method performed by a decoding apparatus according to the present invention comprises: a step of deriving an intra prediction mode for a current block; a step of deriving upper neighboring samples of a plurality of rows for the current block, and left neighboring samples of a plurality of columns; a step of deriving one row of upper reference samples on the basis of the upper neighboring samples; a step of deriving one column of left reference samples on the basis of the left neighboring samples; and a step of generating a prediction sample for the current block by using at least one of the upper reference samples and the left reference samples in accordance with the intra prediction mode.

Abstract: Methods and apparatus for compressing image data are described along with corresponding methods and apparatus for decompressing the compressed image data. An encoder unit, which generates the compressed image data, comprises an input arranged to receive a first image and a second image, wherein the second image is twice the width and height of the first image, a prediction generator arranged to generate a prediction texture from the first image using an adaptive interpolator, a difference texture generator arranged to generate a difference texture from the prediction texture and the second image and in encoder unit arranged to encode the difference texture.

Abstract: Disclosed are a method for decoding a video signal and a device therefore. More particularly, a method for decoding an image based on an intra prediction mode, may comprise the steps of: acquiring a most probable mode (MPM) flag for indicating whether an MPM is applied to a current block, the MPM representing a mode in which an intra prediction mode of the current block is induced from an intra predicted block neighboring the current block; configuring an MPM list, on the basis of whether intra prediction modes of a left neighboring block and an above neighboring block of the current block satisfy predefined conditions, if the MPM is applied to the current block; acquiring an MPM index for indicating, within the MPM list, a specific intra prediction mode; and generating a prediction block for the current block by using the intra prediction mode specified by the MPM index.

Abstract: A three-dimensional data encoding method includes: encoding first information of a first current node or second information of a second current node, the first current node being included in an N-ary tree structure of first three-dimensional points included in a first three-dimensional point cloud, N being 2 or 4, the second current node being included in an octree structure of second three-dimensional points included in a second three-dimensional point cloud. The encoding of the first information or the second information includes encoding the first information using a first encoding pattern including a pattern common to a second encoding pattern used in encoding the second information.

Abstract: Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus includes processing circuitry. For example, the processing circuitry obtains reconstructed samples in a temporal source frame that is different from a current frame, and determines filter coefficients of a filter for a current block in the current frame based on at least the reconstructed samples in the temporal source frame. The processing circuitry generates prediction information of the current block based on the determined filter coefficients. The temporal source frame is an inter coded frame that satisfies at least one of a quantization parameter (QP) requirement, a temporal distance requirement, and a reference picture requirement.

Abstract: A method of video processing includes making a determination, fora conversion between a current video block of a video and a coded representation of the video, of an affine merge candidate selectively according to a rule; and performing the conversion according to the determination. The rule specifies how the affine merge candidate is calculated without use of a log 2(X) operation where X is equal to or less than zero. The affine merge candidate is a motion candidate derived from neighboring affine coded video blocks.

Abstract: An image encoding/decoding method and device according to the present disclosure may configure a reference sample for a cross component prediction of a chroma component block, derive a cross component prediction parameter by using the reference sample, and make a cross component prediction of the chroma component block on the basis of the cross component prediction parameter and a luma component block corresponding to the chroma component block.

Abstract: The present invention relates to an intra prediction mode mapping method and a device using the method. The intra prediction mode includes: decoding flag information providing information regarding whether an intra prediction mode of a plurality of candidate intra prediction modes for the current block is the same as the intra prediction mode for the current block, and decoding a syntax component including information regarding the intra prediction mode for the current block in order to induce the intra prediction mode for the current block if the intra prediction mode from among the plurality of candidate intra prediction modes for the current block is not the same as the intra prediction mode for the current block. Thus, it is possible to increase the efficiency with which are images are decoded.

Abstract: Embodiments of the present application provide an occupancy information prediction method, an encoder, a decoder, and a storage medium. The occupancy information prediction method comprises: when an encoder encodes geometrical information on the basis of an octree, determining encoding information corresponding to a neighboring node of a node to be predicted, and a distance parameter between a child node of the node to be predicted and the neighboring nodes; wherein the encoding information corresponding to the neighboring node comprises occupancy information; determining an occupancy weight corresponding to the child node of the node to be predicted according to the distance parameter, and the encoding information corresponding to the neighboring node; performing a prediction processing on the child node according to the occupancy weight and a preset occupancy threshold set to obtain a node type corresponding to the child node.

Abstract: A decoding method is disclosed. The decoding method comprises: determining an index from a bitstream, the index identifying a coding element in a set of a plurality of coding elements; decoding a picture block from the bitstream using the coding element of the set identified by the index. In a specific embodiment, determining the index comprises: determining, for each coding element in the set, a probability that the coding element was used for encoding the picture block; and determining the index responsive to the determined probabilities.

Abstract: A method of processing an image divided into a plurality of pixel blocks which are processed according to a processing sequence is provided, which comprises, for a current pixel block: determining an application area consisting of a set of pixels in blocks preceding the current block in the processing sequence, for each pixel of the application area, computing a gradient representing a directional change of an intensity at the pixel, and selecting, based on at least one of the computed gradients, an intra prediction video coding mode among a plurality of intra prediction video coding modes usable for encoding and/or decoding the current block.

Abstract: An image decoding method performed by a decoding apparatus according to the present disclosure includes receiving intra prediction information including at least one of most probable mode (MPM) flag information representing whether to derive an intra prediction mode for a current block based on MPM candidates for the current block or planar flag information representing whether to determine the intra prediction mode for the current block as a planar mode, deriving the intra prediction mode for the current block based on the MPM flag information and the planar flag information, deriving a predicted block for the current block based on the intra prediction mode for the current block, and generating a reconstructed picture based on the predicted block.

Abstract: A method can include decoding residual signals to generate quantized coefficient components; determining an inverse scan pattern and generating a quantized block using the inverse scan pattern; deriving a quantization parameter and inversely quantizing the quantized block using the quantization parameter to generate a transformed block; and inversely transforming the transformed block to generate a residual block, in which when the quantization parameter is a chroma quantization parameter, the chroma quantization parameter is generated using a luma quantization parameter and an offset parameter indicating a relationship between the luma quantization parameter and the chroma quantization parameter, the luma quantization parameter is derived using a differential quantization parameter and a quantization parameter predictor, and the differential quantization parameter is generated by entropy decoding, and parameters are set according to certain conditions.

Abstract: There is provided a computer-implemented method and a decompression unit for decompressing a compressed block of data in accordance with a multi-level difference table. The compressed block of data represents a block of image data comprising a plurality of image element values, wherein each level of the multi-level difference table comprises a plurality of entries. An origin value for the block of image data is determined using data representing the origin value from the compressed block of data. A level within the multi-level difference table for the block of image data is identified using an indication of the level from the compressed block of data.