Image decoding method and image encoding method using motion compensation, and transmission method for image data
The present invention relates to a method for encoding/decoding a video. To this end, the method for decoding a video may include: deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block, deriving a temporal merge candidate from a co-located block of the current block, and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein a reference picture for the temporal merge candidate is selected based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block.
1 . An image decoding method performed by a decoding apparatus, the method comprising:
obtaining image information comprising information related to motion compensation from a bitstream, wherein the information related to motion compensation includes inter prediction indication information;
determining that bi-prediction is applied to a current block based on the inter prediction indication information;
deriving motion information candidates based on neighboring blocks of the current block;
deriving motion information of the current block based on at least one of the motion information candidates;
generating predicted blocks of the current block based on the motion information of the current block; and
generating a predicted block of the current block based on weight information for the bi-prediction and the predicted blocks,
wherein the inter prediction indication information indicates that the bi-prediction is applied to the current block,
wherein the motion information candidates include spatial candidates derived based on spatial neighboring blocks of the current block,
wherein the information related to the motion compensation includes the weight information for the bi-prediction,
wherein the weight information for the bi-prediction is signaled in a unit of coding unit,
wherein the weight information for the bi-prediction indicates one of weight values including a negative weight value,
wherein the weight information for the bi-prediction is based on a truncated unary binarization, and
wherein the weight information for the bi-prediction is decoded based on a context model.
2 . The method of claim 1 , wherein the bi-prediction is based on reference picture lists, and
wherein a prediction direction for a first reference pictures list is different from a prediction direction for a second reference picture list.
3 . An image encoding method performed by an encoding apparatus, the method comprising:
determining that bi-prediction is applied to a current block;
deriving motion information candidates based on neighboring blocks of the current block;
deriving motion information of the current block based on at least one of the motion information candidates;
generating predicted blocks of the current block based on the motion information of the current block;
generating a predicted block of the current block based on weight information for the bi-prediction and the predicted blocks;
generating information related to motion compensation; and
encoding image information including the information related to the motion compensation,
wherein the information related to motion compensation includes inter prediction indication information indicating that the bi-prediction is applied to the current block,
wherein the motion information candidates include spatial candidates derived based on spatial neighboring blocks of the current block,
wherein the information related to the motion compensation includes the weight information for the bi-prediction,
wherein the weight information for the bi-prediction is signaled in a unit of coding unit,
wherein the weight information for the bi-prediction indicates one of weight values including a negative weight value,
wherein the weight information for the bi-prediction is based on a truncated unary binarization, and
wherein the weight information for the bi-prediction is encoded based on a context model.
4 . The method of claim 3 , wherein the bi-prediction is based on reference picture lists, and
wherein a prediction direction for a first reference pictures list is different from a prediction direction for a second reference picture list.
5 . A transmission method for image data, the method comprising:
obtaining a bitstream of encoded image information generated based on an image encoding method, wherein the image encoding method comprises determining that bi-prediction is applied to a current block, deriving motion information candidates based on neighboring blocks of the current block, deriving motion information of the current block based on at least one of the motion information candidates, generating predicted blocks of the current block based on the motion information of the current block, generating a predicted block of the current block based on weight information for the bi-prediction and the predicted blocks, generating information related to motion compensation, and encoding image information including the information related to the motion compensation; and
transmitting the image data comprising the bitstream,
wherein the information related to motion compensation includes inter prediction indication information indicating that the bi-prediction is applied to the current block,
wherein the motion information candidates include spatial candidates derived based on spatial neighboring blocks of the current block,
wherein the information related to the motion compensation includes the weight information for the bi-prediction,
wherein the weight information for the bi-prediction is signaled in a unit of coding unit,
wherein the weight information for the bi-prediction indicates one of weight values including a negative weight value,
wherein the weight information for the bi-prediction is based on a truncated unary binarization, and
wherein the weight information for the bi-prediction is encoded based on a context model.