METHOD AND APPARATUS FOR ENCODING/DECODING IMAGE
A method and an apparatus for encoding/decoding an image according to the present invention may determine a reference area that is a pre-reconstructed area spatially adjacent to a current block on the basis of reference information for specifying the position of a reference area used for predicting a current block and may predict the current block on the basis of the reference area.
1 . A method of decoding video data, the method comprising:
determining initial motion information of a current block;
determining delta motion information of the current block;
modifying the initial motion information of the current block by using the delta motion information; and
performing motion compensation of the current block by using the modified motion information.
2 . The method of claim 1 , wherein determining the delta motion information comprises:
determining a search region for modifying the initial motion information;
generating a sum of absolute difference (SAD) list from the search region, the SAD list including SAD candidates, each of the SAD candidates corresponding to each of search positions in the search region; and
updating the delta motion information based on the SAD candidates in the SAD list.
3 . The method of claim 2 , wherein an SAD candidate is determined as an SAD value between an L0 block and an L1 block, and
wherein the SAD value is calculated based on only samples belonging to one of odd sample lines or even sample lines in the L0 and L1 blocks.
4 . The method of claim 3 , wherein a position of the L0 block is determined based on a position of a L0 reference block of the current block and a predetermined offset, and
wherein the offset includes at least one of a non-directional offset or a directional offset.
5 . The method of claim 4 , wherein updating the delta motion information is performed based on a comparison result between a reference SAD candidate and a predetermined threshold value, and
wherein the reference SAD candidate means an SAD candidate corresponding to the non-directional offset.
6 . The method of claim 5 , wherein the threshold value is determined as a product of width and height of the current block.
7 . The method of claim 6 , wherein, in response to the reference SAD candidate being greater than or equal to the threshold value, an SAD candidate having a minimum value among the SAD candidates in the SAD list is identified, and
wherein the delta motion information is updated based on an offset corresponding to the identified SAD candidate.
8 . The method of claim 7 , wherein the modification of the initial motion information is selectively performed in consideration of at least one of a size of the current block, a distance between a current picture and a reference picture of the current block, an inter prediction mode, or a prediction direction.
9 . A method of encoding video data, the method comprising:
determining initial motion information of a current block;
determining delta motion information of the current block;
modifying the initial motion information of the current block by using the delta motion information; and
performing motion compensation of the current block by using the modified motion information.
10 . A non-transitory computer readable medium for storing a bitstream generated by a video encoding method, the video encoding method comprising:
determining initial motion information of a current block;
determining delta motion information of the current block;
modifying the initial motion information of the current block by using the delta motion information; and
performing motion compensation of the current block by using the modified motion information.