Abstract: An image encoding/decoding method and apparatus are provided. The image decoding method performed by the image decoding apparatus, according to the present disclosure, may comprise the steps of: determining whether a color space transformation is applied to residual samples of a current block; determining quantization parameter of the current block on the basis of whether the color space transformation is applied; and determining a transformation coefficient of the current block on the basis of the quantization parameter. The step of determining the quantization parameter may be performed by limiting the range of an effective value of the quantization parameter such that a value of the quantization parameter has a value less than or equal to a predetermined upper value and greater than or equal to a predetermined lower value.

Abstract: An image encoding/decoding method and apparatus for signaling a VPS and a recording medium storing a bitstream are provided. An image decoding method may comprise obtaining first information indicating whether each output layer set (OLS) specified by a video parameter set (VPS) includes only one layer, obtaining second information indicating the number of decoded picture buffer (DPB) parameter syntax structures in the VPS, based on the first information, obtaining the DPB parameter syntax structures in the VPS based on the second information, and managing a DPB based on the DPB parameter syntax structures.

Abstract: Disclosed herein are an image encoding and decoding method and apparatus for signaling information on a subpicture and picture header, and a method of transmitting a bitstream. The image decoding method according to the present disclosure may include acquiring a first flag specifying whether information on a subpicture is present in a bitstream, acquiring a second flag specifying whether picture header information is present in a slice header, and decoding the bitstream based on the first flag and the second flag. When the first flag specifies that the information on the subpicture is present in the bitstream, the second flag may have a value specifying that the picture header information is not present in the slice header.

Abstract: A method for intra prediction comprises determining a first MPM candidate corresponding to a left-side candidate block on the basis of a position of the left-side candidate block adjacent to a left side of a current block; determining a second MPM candidate corresponding to an upper-end candidate block on the basis of a position of the upper-end candidate block adjacent to an upper end of the current block; generating an MPM candidate list including a plurality of MPM candidates, on the basis of the first MPM candidate and the second MPM candidate; and determining one MPM candidate of the plurality of the MPM candidates that constitute the MPM candidate list as an intra prediction mode of the current block, and performing intra prediction for the current block on the basis of the determined intra prediction mode to generate a prediction block corresponding to the current block.

Abstract: Provided is an image encoding/decoding method and apparatus. The image decoding method comprises obtaining subpicture information from a bitstream, deriving one or more subpictures in a current picture based on the subpicture information, and decoding a current subpicture in the current picture based on the subpicture information. The subpicture information may comprise a first flag specifying whether each of the one or more subpictures is treated as a picture, and, based on the bitstream including at least one first layer referring to a current layer including the current picture, the first flag for the first subpicture included in a first layer and corresponding to the current subpicture, and the first flag for the current subpicture have the same value.

Abstract: According to embodiments of the present document, information for carrying out in-loop filtering across virtual boundaries can be efficiently signaled. For example, in-loop filtering can be carried out on the basis of signaling of information which is related to whether in-loop filtering across virtual boundaries is enabled or not.

Abstract: Disclosed herein are an image encoding/decoding method and apparatus. An image decoding method performed by an image encoding apparatus may include acquiring size information indicating a size of a current slice corresponding to at least a portion of a current picture from a bitstream and determining the size of the current slice based on the size information.

Abstract: A deblocking filtering method, a boundary strength (bS) deriving method, and encoding/decoding method and apparatus using the methods are provided. The bS deriving method includes the steps of: deriving a boundary of a deblocking filtering unit block which is a unit block on which deblocking filtering is performed; and setting a bS for each bS setting unit block in the deblocking filtering unit block. Here, the step of setting the bS includes setting a bS value of a target boundary corresponding to the boundary of the deblocking filtering unit block as the bS setting unit block.

Abstract: The present invention relates to a method for signaling image information and to a decoding method using same. The method for signaling image information according to the present invention comprises: a step of performing inter-prediction for a current picture; and a step of signaling information including the result of said inter-prediction and reference picture information indicating reference pictures usable in said inter prediction, wherein said reference picture information contains pieces of picture order count (POC) information of said usable reference pictures. The POC information of said usable reference pictures in said reference picture information is configured such that POCs for the pictures existing before said current picture in terms of a POC sequence are located at the front, and POCs for the pictures existing after said current picture in terms of a POC sequence are located following the POCs located at the front.

Abstract: A video decoding method performed by a video decoding device according to the present document comprises the steps of: parsing a flag pertaining to a weighted prediction from a bitstream; parsing the syntax of a prediction weighted table from the bitstream based on the flag; performing a weighted prediction for the current block in the current picture based on the prediction weighted table syntax to generate prediction samples for the current block; generating residual samples based on residual information acquired from the bitstream; and generating reconstructed samples for the current block based on the prediction samples and the residual samples, wherein the prediction weighted table syntax can be parsed from the picture header of the bitstream based on the value of the flag being 1, and can be parsed from the slice header of the bitstream based on the value of the flag being 0.

Abstract: A method or coding image information, according to the present invention, comprises the steps of: binarizing according to different techniques, index values of forward prediction, backward prediction, and bidirectional prediction, depending on whether the bidirectional prediction is applied when inter-predicting a current block; and entropy coding a binarized codeword, wherein whether to apply the bidirectional prediction when inter-predicting the current block can be determined on the basis of the size of the current block. As a result, provided are a method for binarizing an inter-prediction direction of a prediction unit having a specific size, and an apparatus using same.

Abstract: An image encoding/decoding method and apparatus are provided. The image decoding method comprises obtaining, from a bitstream, video coding layer (VCL) network abstraction layer (NAL) unit type information of a current picture and first flag information specifying whether a subpicture included in the current picture is treated as one picture, determining a NAL unit type of each of a plurality of slices included in the current picture, based on the obtained VCL NAL unit type information, and decoding the plurality of slices based on the determined NAL unit type and the first flag information. The current picture may comprise two or more subpictures based on at least some of the plurality of slices having different NAL unit types, and the first flag information may have a predetermined value specifying that each of the two or more subpictures is treated as one picture based on at least some of the plurality of slices having different NAL unit types.

Abstract: An image encoding/decoding method and device are provided. An image decoding method performed by an image decoding device according to the present disclosure may comprise the steps of: determining a prediction mode of the current block on the basis of prediction information obtained from a bitstream; on the basis of the prediction mode of the current block, obtaining a flag indicating whether a color space transform is applied to a residual sample of the current block; determining a quantization parameter of the current block on the basis of the flag; and determining a transform coefficient of the current block on the basis of the quantization parameter.

Abstract: An image decoding method performed by a decoding apparatus according to the present document comprises the steps of: acquiring a flag indicating whether a picture header (PH) network abstraction layer (NAL) unit exists; acquiring a PH on the basis of the flag; and decoding a current picture related to the PH on the basis of the PH.

Abstract: The present invention relates to a video encoding method, to a video decoding method, and to an apparatus using same. The video encoding method according to the present invention comprises the steps of: setting a tile and a slice for the inputted current picture; performing encoding based on the tile and the slice; and a step of transmitting the encoded video information. The current picture may include one or more tiles and one or more slices. The largest coding units (hereinafter, referred to as LCUs) in the slice may be arranged based on a tile scan.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method comprises determining whether a current entry in a reference picture list structure is an inter-layer reference picture (ILRP) entry, determining whether a current layer including a current picture has a plurality of direct reference layers, based on the current entry being the ILRP entry, acquiring a layer index of the current entry for a direct reference layer list from a bitstream, based on the current layer having a plurality of direct reference layers, and determining a direct reference layer including the current entry based on the layer index. The obtaining of the layer index may be skipped based on the current layer doing not have a plurality of direct reference layers.

Abstract: An image encoding/decoding method and apparatus is provided. The image decoding method comprises obtaining, from a bitstream, a first flag specifying whether sublayer level information is present for each of one or more sublayers in a current layer, and obtaining, from the bitstream, the sublayer level information based on the first flag. The first flag may be obtained in a descending order of temporal identifier values for the one or more sublayers.

Abstract: According to embodiments of the present document, the subjective/objective quality of an image can be improved through image coding on the basis of subpictures and/or virtual boundaries, and consumption of hardware resources required for coding can be reduced.

Abstract: An image decoding method according to the present invention includes: receiving information on a set of reference pictures for configuring a set of reference pictures of a current picture, wherein the information on the set of reference pictures includes the most significant bit (MSB) information that may calculate the MSB of the picture order count (POC) of a long-term reference picture relative to the current picture, and flag information that represents whether there is MSB information; and eliciting the set of reference pictures by using received MSB information when the flag information is 1, and performing marking on the reference picture, wherein the flag information may be 1 when a temporal sub-layer identifier is 0, and there is at least one POC value for which a remainder obtained by dividing by a maximum value MaxPicOrderCntLsb capable of being represented by the LSB is the same as the least significant bit (LSB) of the POC of the long-term reference picture, in a set of POCs of a previous picture

Abstract: A video decoding method performed by a video decoding apparatus according to the present document may comprise the steps of: parsing a prediction weighted table syntax from a bitstream; parsing number information about weighted reference pictures in a reference picture list from the prediction weighted table syntax; deriving a weighting factor-related flag about the reference picture list on the basis of the number information; performing weighted prediction on a current block on the basis of the weighting factor-related flag so as to derive prediction samples of the current block; generating residual samples on the basis of residual information obtained from the bitstream; and reconstructing a current picture on the basis of the prediction samples and the residual samples, wherein the prediction weighted table syntax is parsed from a picture header of the bitstream.