Inter prediction method and apparatus therefor
According to the present invention, an inter prediction method comprises the steps of: generating a merge candidate list for a block to be predicted, wherein the block is to correspond to a current prediction unit; deriving, on the basis of one of a plurality of merge candidates constituting the merge candidate list, motion information on the block to be predicted; and performing, on the basis of the derived motion information, a prediction on the block to be predicted so as to generate a prediction block corresponding to the current prediction unit.
1. An image decoding method performed by a decoding apparatus, the method comprising:
receiving information on a parallel merge level which represents a size of a parallel merging unit region;
receiving merge index information;
constructing a merging candidate list including spatial merging candidates for a current block;
deriving motion information of the current block, based on one of the spatial merging candidates indicated by the merge index information in the merging candidate list;
deriving prediction samples of the current block based on the derived motion information; and
generating a reconstructed picture based on the prediction samples,
wherein the current block belongs to the parallel merging unit region,
wherein the current block is related to a prediction unit(PU), and the PU is one of PUs partitioned from a coding unit (CU),
wherein for the PU, within the parallel merging unit region, the spatial merging candidates are identical to spatial merging candidates of a 2N×2N PU which has a same size as the parallel merging unit region, and
wherein the spatial merging candidates of the 2N×2N PU which has the same size as the parallel merging unit region, are derived from a lower left corner neighboring block, a left neighboring block, an upper right corner neighboring block, an upper neighboring block and an upper left corner neighboring block of the parallel merging unit region.
2. The method of claim 1 , wherein when a value of the information on the parallel merge level is 0, the size of the parallel merging unit region is 4×4.
3. The method of claim 1 , wherein when the value of the information on the parallel merge level is greater than 0, motion information for each of the PUs contained in the parallel merging unit region can be derived in parallel.
4. The method of claim 1 , wherein when a value of the information on the parallel merge level is 1, the size of the parallel merging unit region is 8×8, and
wherein when a value of the information on the parallel merge level is 2, the size of the parallel merging unit region is 16×16.
5. The method of claim 1 , wherein when a value of the information on the parallel merge level is 3, the size of the parallel merging unit region is 32×32, and
wherein when a value of the information on the parallel merge level is 4, the size of the parallel merging unit region is 64×64.
6. The method of claim 1 , wherein when the size of the CU is 8×8 and the size of the parallel merging unit region is larger than 4×4, the PUs share the spatial merging candidates.
7. An image encoding method performed by an encoding apparatus, the method comprising:
deriving spatial merging candidates for a current block when a merge mode is applied to the current block;
constructing a merging candidate list including the spatial merging candidates for the current block;
selecting a merging candidate from the merging candidate list;
generating merge index information for indicating the selected merging candidate from the merging candidate list;
generating information on a parallel merge level which represents a size of a parallel merging unit region; and
encoding image information including the merge index information and the information on the parallel merge level,
wherein the current block belongs to the parallel merging unit region,
wherein the current block is related to a prediction unit(PU), and the PU is one of PUs partitioned from a coding unit (CU),
wherein for the PU, within the parallel merging unit region, the spatial merging candidates are identical to spatial merging candidates of a 2N×2N PU which has a same size as the parallel merging unit region, and
wherein the spatial merging candidates of the 2N×2N PU which has the same size as the parallel merging unit region, are derived from a lower left corner neighboring block, a left neighboring block, an upper right corner neighboring block, an upper neighboring block and an upper left corner neighboring block of the parallel merging unit region.
8. A non-transitory decoder-readable storage medium for storing encoded image information causing a decoding apparatus to perform an image decoding method, the method comprising:
receiving information on a parallel merge level which represents a size of a parallel merging unit region;
receiving merge index information;
constructing a merging candidate list including spatial merging candidates for a current block;
deriving motion information of the current block, based on one of the spatial merging candidates indicated by the merge index information in the merging candidate list;
deriving prediction samples of the current block based on the derived motion information; and
generating a reconstructed picture based on the prediction samples,
wherein the current block belongs to the parallel merging unit region,
wherein the current block is related to a prediction unit(PU), and the PU is one of PUs partitioned from a coding unit (CU),
wherein for the PU, within the parallel merging unit region, the spatial merging candidates are identical to spatial merging candidates of a 2N×2N PU which has a same size as the parallel merging unit region, and
wherein the spatial merging candidates of the 2N×2N PU which has the same size as the parallel merging unit region, are derived from a lower left corner neighboring block, a left neighboring block, an upper right corner neighboring block, an upper neighboring block and an upper left corner neighboring block of the parallel merging unit region.