Method and apparatus for inter prediction using motion vector candidate based on temporal motion prediction
An inter prediction method according to the present invention comprises: a step for deriving reference motion information related to a unit to be decoded in a current picture; and a step for performing motion compensation for the unit to be decoded, using the reference motion information that has been derived. According to the present invention, image encoding/decoding efficiency can be enhanced.
1. A video decoding method, comprising:
deriving spatial motion information from a neighboring unit of a decoding target unit;
obtaining index information relating to temporal motion information of the decoding target unit from a bitstream,
wherein the index information specifies a first reference picture having the temporal motion information of the target unit among a plurality of reference pictures in a reference picture list, and
wherein the neighboring unit is adjacent to the decoding target unit or is disposed at a corner of the decoding target unit;
selecting, based on the index information, the first reference picture among the plurality of the reference pictures in the reference picture list;
deriving the temporal motion information from a collocated unit of the selected first reference picture, the first reference picture having a different temporal order from a picture including the decoding target unit,
wherein the temporal motion information includes motion vector of the collocated unit;
generating a merge candidate list for the decoding target unit including derived spatial motion information and the derived temporal motion information;
performing motion compensation on the decoding target unit by using the merge candidate list,
generating a prediction block of the current block using a result of the motion compensation;
obtaining a residual block of the current block; and
generating a reconstructed block of the current block by adding the prediction block and the residual block,
wherein the step of performing the motion compensation comprises:
obtaining a merge index of the decoding target unit;
selecting motion information indicated by the merge index among merge candidates included in the merge candidate list; and
performing the motion compensation for the decoding target unit using the selected motion information.
2. A video encoding method, comprising:
deriving spatial motion information from a neighboring unit of an encoding target unit,
wherein the neighboring unit is adjacent to the encoding target unit or is disposed at a corner of the encoding target unit;
deriving temporal motion information from a collocated unit of a first reference picture, the first reference picture having a different temporal order from a picture including the encoding target unit,
wherein the temporal motion information includes motion vector of the collocated unit;
generating a merge candidate list for the encoding target unit including the derived spatial motion information and the derived temporal motion information;
encoding, based on the merge candidate list, a merge index of the encoding target unit;
encoding index information relating to the temporal motion information of the encoding target unit;
obtaining a prediction block of the current block;
obtaining a residual block of the current block based on the prediction of the current block; and
encoding the residual block of the current block;
wherein the index information specifies the first reference picture having the temporal motion information of the encoding target unit among a plurality of reference pictures in a reference picture list.
3. A non-transitory computer-readable recording-medium storing a bitstream which is generated by a video encoding method,
the method comprising:
deriving spatial motion information from a neighboring unit of an encoding target unit,
wherein the neighboring unit is adjacent to the encoding target unit or is disposed at a corner of the encoding target unit;
deriving temporal motion information from a collocated unit of a first reference picture, the first reference picture having a different temporal order from a picture including the encoding target unit,
wherein the temporal motion information includes motion vector of the collocated unit;
generating a merge candidate list for the encoding target unit including the derived spatial motion information and the derived temporal motion information;
encoding, based on the merge candidate list, a merge index of the encoding target unit;
encoding index information relating to the temporal motion information of the encoding target unit;
obtaining a prediction block of the current block;
obtaining a residual block of the current block based on the prediction of the current block; and
encoding the residual block of the current block;
wherein the index information specifies the first reference picture having the temporal motion information of the encoding target unit among a plurality of reference pictures in a reference picture list.