Industry-University Cooperation Foundation KOREA AEROSPACE UNIVERSITY

There is provided an image encoding/decoding method and apparatus. The image decoding method comprises decoding size information of a quantization group from a bitstream, acquiring a delta quantization parameter of a current block on the basis of the size information of the quantization group, and deriving a quantization parameter for the current block on the basis of the delta quantization parameter.

An image encoding/decoding method is provided. An image decoding method of the present invention may comprise restoring an intra-prediction mode of a current chroma block, deriving at least one representative value based on a neighboring sample of the current chroma block and a neighboring sample of a corresponding luma block corresponding to the current chroma block in case the intra-prediction mode is a CCLM (Cross-Component Linear Model) mode, deriving a parameter of CCLM by using the at least one representative value, and generating a prediction block of the current chroma block by using the parameter of CCLM.

An image encoding/decoding method and apparatus are disclosed. The method of decoding an image according to the present invention, comprises, generating a first prediction block of a current block, generating a second prediction block of the current block and generating a final prediction sample of the current block using a sample unit weighted sum of the first prediction block and the second prediction block, wherein a weight used for the sample unit weighted sum is determined based on a location of a current luma sample and a geometric prediction mode (GPM) boundary line for partitioning the current block.

Disclosed herein are a decoding method and apparatus and an encoding method and apparatus for deriving an intra prediction mode. An intra prediction mode may be derived using a method for deriving an intra prediction mode based on a neighbor block of the target block, a method for deriving an intra prediction mode using signaling of the intra prediction mode of the target block, or a method for deriving an adaptive intra prediction mode based on the type of a target slice. An MPM list may be used to derive the intra prediction mode, and a temporal neighbor block or the like may be used to configure the MPM list.

An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus according to the present invention may comprise deriving an intra-prediction mode of a current block, and performing intra-prediction for the current block based on the intra-prediction mode. The deriving of the intra-prediction mode may comprise decoding a predetermined mode sameness indicator.

Disclosed herein is an image decoding method. The method of decoding an image comprises obtaining prediction information and residual signal information for a current block from a bitstream and reconstructing, based on the obtained prediction information and the residual signal information, the current block, wherein the prediction information is obtained through entropy decoding, and wherein a context model used for the entropy decoding of the prediction information is determined based on a prediction mode of a neighboring block of the current block.

Disclosed herein are an image encoding/decoding method and apparatus. The image decoding method of the present disclosure may include obtaining maximum transform block size information, deriving a maximum transform block size on the basis of the maximum transform block size information, and, determining whether or not a secondary inverse transform is applied to the current block on the basis of the maximum transform block size and a horizontal size and a vertical size of a current block.

Disclosed herein are a decoding method and apparatus and an encoding method and apparatus that perform inter-prediction using a motion vector predictor. For a candidate block in a col picture, a scaled motion vector is generated based on a motion vector of the candidate block. When the scaled motion vector indicates a target block, a motion vector predictor of the target block is generated based on the motion vector of the candidate block. The motion vector predictor is used to derive the motion vector of the target block in a specific inter-prediction mode such as a merge mode and an AMVP mode.

Disclosed herein is a method of decoding an image. The method includes generating an inter prediction block by performing inter prediction with respect to a current block, generating an intra prediction block by performing intra prediction with respect to the current block, determining a first weight and a second weight, and generating a final prediction block by respectively applying the first weight and the second weight to the inter prediction block and the intra prediction block. The generating of the intra prediction block includes generating the intra prediction block using a predefined intra prediction mode.

Disclosed herein is an image decoding method. The method of decoding an image comprises obtaining prediction information and residual signal information for a current block from a bitstream and reconstructing, based on the obtained prediction information and the residual signal information, the current block, wherein the prediction information is obtained through entropy decoding, and wherein a context model used for the entropy decoding of the prediction information is determined based on a prediction mode of a neighboring block of the current block.