Samsung Electronics Co., Ltd.

Lg Electronics Inc.

Minwoo Park

Minsoo Park

Seungsoo Jeong

Anish Tamse

Kiho Choi

Yinji Piao

Narae Choi

Woongil Choi

Chanyul Kim

Gahyun Ryu

Kwangpyo Choi

Seung-soo Jeong

Kyungah Kim

Sanghyun Lee

Yin-Ji Piao

Yumi Sohn

Quockhanh Dinh

Yin-ji Piao

Bora Jin

Changwoan Yang

Seungjin Choi

Yoomin Park

Hanhyo Kim

Heechul Yang

Tackwon Han

Jinyoung Lee

Kwonyeol Park

Leechun Kim

An image decoding method includes: comparing a size of a current image including a current block with a size of a reference image; selecting, in the reference image, reference samples corresponding to current samples in the current block according to a motion vector of the current block; and reconstructing the current block based on the reference samples, wherein, when the size of the reference image is greater than the size of the current image, the reference samples are spaced apart from one another in the reference image by an interval corresponding to a result of the size comparison.

Method and device for encoding video on basis of video size, and method and device for decoding video on basis of video size

Provided is a video decoding method including: obtaining, from a bitstream, intra prediction mode information indicating an intra prediction mode of a current block; determining an interpolation filter set to be used in prediction of the current block, based on at least one of a size of the current block and the intra prediction mode indicated by the intra prediction mode information; determining a reference location to which a current sample of the current block refers according to the intra prediction mode; determining, in the interpolation filter set, an interpolation filter that corresponds to the reference location; determining a prediction value of the current sample, according to reference samples of the current block and the interpolation filter; and reconstructing the current block, based on the prediction value of the current sample.

Encoding method and apparatus therefor, and decoding method and apparatus therefor

Video encoding method and video decoding method

Provided are a video decoding method and a video decoding device, which, during video encoding and decoding processes, obtain most probable mode (MPM) information indicating whether to use MPMs of a current block determined based on at least two of a prediction mode of a left neighboring block adjacent to a left side of the current block, a prediction mode of an upper neighboring block adjacent to an upper side of the current block, and a right neighboring block adjacent to a right side of the current block, obtain extended intra mode set information indicating whether to use an extended intra mode set configured based on the MPMs, and determine an intra prediction mode of the current block based on the MPM information and the extended intra mode set information.

Selection of an extended intra prediction mode

Provided are a video decoding method and apparatus which, during video encoding and decoding processes, determine whether a current block is in contact with an upper boundary of a largest coding unit including the current block, when it is determined that the current block is in contact with the upper boundary of the largest coding unit, determine an upper reference line of the current block as one reference line, when it is determined that the current block is not in contact with the upper boundary of the largest coding unit, determine the upper reference line of the current block based on N reference lines, and use the determined upper reference line.

Method and device for video decoding, and method and device for video encoding

An image decoding method may include: obtaining, from a sequence parameter set of a bitstream, information indicating a plurality of first reference image lists for an image sequence including a current image; obtaining, from a group header of the bitstream, an indicator for a current block group including a current block in the current image; obtaining a second reference image list by modifying a first reference image list indicated by the indicator, from among the plurality of first reference image lists, into the second reference image list; and prediction-decoding a lower block of the current block based on a second reference image included in the second reference image list.

Apparatuses for encoding and decoding image, and methods for encoding and decoding image thereby

An image decoding method and apparatus obtain intra prediction feature data of a current block from a bitstream, determine an intra flow indicating a reference pixel of a current pixel in the current block, by applying the intra prediction feature data, neighboring pixels of the current block, and coding context information of the current block to a neural network, obtain a predicted pixel of the current pixel based on the intra flow of the current block, and reconstruct the current block based on the predicted pixel.

Image decoding apparatus and method and image encoding apparatus and method

Provided are an image decoding method and apparatus. The image decoding method includes identifying at least two neighboring sub-blocks that have a same motion vector and are adjacent to each other from among a plurality of neighboring sub-blocks adjacent to a current block, determining a representative motion vector and representative location information corresponding to the at least two neighboring sub-blocks, determining a parameter of a model for determining a motion vector based on the representative motion vector and the representative location information, determining a motion vector of a current sub-block included in the current block, based on location information of the current sub-block and the parameter, and predicting the current block based on the motion vector of the current sub-block wherein the representative motion vector is determined based on the same motion vector, and the representative location information indicates coordinates that are determined based on the at least two neighboring sub-blocks.

Image decoding method and apparatus, and image encoding method and apparatus

A method of decoding an image, including obtaining a motion vector of a current block; obtaining a preliminary prediction block based on a reference block indicated by the motion vector in a reference image; obtaining a final prediction block for the current block by applying, to a neural network, at least one of a picture order count (POC) map including a POC difference between the reference image and a current image including the current block, the preliminary prediction block, and a quantization error map; and reconstructing the current block based on the final prediction block and a residual block obtained from a bitstream, wherein sample values of the quantization error map are calculated based on a quantization parameter for the reference block.

Method and apparatus for image decoding and image encoding using AI prediction block

Provided is an image decoding method including determining a plurality of coding units in a chroma image by hierarchically splitting the chroma image, based on a split shape mode of blocks in the chroma image of a current image, and decoding the current image, based on the plurality of coding units in the chroma image. In this regard, the determining of the plurality of coding units in the chroma image may include, when a size or an area of a chroma block from among a plurality of chroma blocks to be generated by splitting a current chroma block in the chroma image is equal to or smaller than a preset size or a preset area, not allowing splitting of the current chroma block based on a split shape mode of the current chroma block, and determining at least one coding unit included in the current chroma block.

Method and apparatus for image encoding, and method and apparatus for image decoding

Provided is a video decoding method including: obtaining, from a picture parameter set, a quantization parameter (QP) initial value to be applied to a current picture, and picture header QP difference value information; when the picture header QP difference value information indicates that QP difference value information is present in a picture header of the current picture, obtaining a first QP difference value for the current picture from the picture header; determining a QP for a coding unit included in the current picture, by using the QP initial value and the first QP difference value; obtaining transform coefficients of the coding unit by performing inverse quantization on the coding unit by using the QP; and reconstructing the coding unit by using the transform coefficients.

Video decoding method and apparatus for obtaining quantization parameter, and video encoding method and apparatus for transmitting quantization parameter

A video decoding method includes, determining a center motion vector of a current block by using a base motion vector of the current block based on affine model-based inter-prediction being performed in the current block, determining a reference range of an area to be referred to, with respect to the current block, based on a size of the current block, based on a reference area having a size of the reference range with respect to a point in a reference picture of the current block, the point being indicated by a central motion vector of the current block, deviating from or including a boundary of the reference picture, changing the reference area by parallelly translating the reference area into a current picture, and determining prediction samples of sub-blocks of the current block in the changed reference area from the reference picture.

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Suwon-si, South Korea

Minwoo Park