Method and apparatus using boundary matching for mode selection in video coding system
A method and apparatus for video coding. According to the method, a set of candidates associated with coding modes or mode parameters are determined. Boundary matching costs associated with the set of candidates are determined, where each of the boundary matching costs is determined for one target candidate of the set of candidates. The costs are calculated by using reconstructed or predicted samples of the current block and one or more neighboring blocks of the current block. Each of the boundary matching costs is calculated using one target configuration selected from a plurality of configurations. A final candidate is selected from the set of candidates based on the boundary matching costs. The current block is encoded or decoded using the final candidate.
1 . A method of video coding, the method comprising:
receiving input data associated with a current block, wherein the input data comprise pixel data for the current block to be encoded at an encoder side or encoded data associated with the current block to be decoded at a decoder side;
determining a set of candidates associated with coding modes or mode parameters;
determining boundary matching costs associated with the set of candidates, wherein each of the boundary matching costs is determined, for one target candidate of the set of candidates, by using reconstructed or predicted samples of the current block determined according to said one target candidate and neighboring reconstructed or predicted samples of one or more neighboring blocks of the current block, and wherein each of the boundary matching costs is calculated using one target configuration selected from a plurality of configurations;
determining a final candidate from the set of candidates based on the boundary matching costs; and
encoding or decoding the current block using the final candidate,
wherein each of the boundary matching costs is determined for one weighting using the reconstructed samples of the current block derived according to said one weighting, and a weighting index is signaled at the encoder side or parsed at the decoder side for selecting a final weighting value from re-ordered weightings according to the boundary matching costs.
2 . The method of claim 1 , wherein at least one of the plurality configurations excludes, for said determining boundary matching costs, top-side pixels or left-side pixels of the current block and corresponding top-side pixels or corresponding left-side pixels of said one or more neighboring blocks.
3 . The method of claim 2 , wherein said at least one of the plurality configurations depends on at least two motion vectors of the current block and said one or more neighboring blocks.
4 . The method of claim 3 , wherein the top-side pixels or the left-side pixels of the current block and the corresponding top-side pixels or the corresponding left-side pixels of said one or more neighboring blocks are excluded if one or more motion vector differences between the current block and said one or more neighboring blocks exceed a threshold on a corresponding top side or a corresponding left side.
5 . The method of claim 3 , wherein similarity or differences of said at least two motion vectors of the current block and said one or more neighboring blocks are determined on a pixel-wise, subblock-wise, or block-wise basis.
6 . The method of claim 1 , wherein at least one of the plurality configurations only includes, for said determining boundary matching costs, top-side pixels or left-side pixels of the current block and corresponding top-side pixels or corresponding left-side pixels of said one or more neighboring blocks.
7 . The method of claim 1 , wherein at least one of the plurality configurations calculates boundary matching in an angular direction other than a horizontal direction and a vertical direction.
8 . The method of claim 7 , wherein one or more syntax elements associated with the angular direction is signaled in a bitstream at the encoder side or parsed from the bitstream at the decoder side.
9 . The method of claim 8 , wherein said one or more syntax elements are signaled in the bitstream or parsed from the bitstream in a CU (coding unit), PU (prediction unit) or CTU (coding tree unit) level.
10 . The method of claim 7 , wherein the angular direction of the current block is predicted based on the angular direction of one neighboring block.
11 . The method of claim 7 , wherein the angular direction of the current block is implicitly determined by analyzing context information of L-shape neighboring pixels of the current block.
12 . The method of claim 1 , wherein the set of candidates corresponds to weightings of BCW.
13 . The method of claim 1 , wherein each of the boundary matching costs is calculated using one target configuration selected from a plurality configurations according to one or more coding information or contexts of the current block and/or said one or more neighboring blocks of the current block.
14 . A method of video coding, the method comprising:
receiving input data associated with a current block, wherein the input data comprise pixel data for the current block to be encoded at an encoder side or encoded data associated with the current block to be decoded at a decoder side;
determining a set of candidates associated with coding modes or mode parameters;
determining boundary matching costs associated with the set of candidates, wherein each of the boundary matching costs is determined, for one target candidate of the set of candidates, by using reconstructed or predicted samples of the current block determined according to said one target candidate and neighboring reconstructed or predicted samples of one or more neighboring blocks of the current block, and wherein each of the boundary matching costs is calculated using one target configuration selected from a plurality of configurations;
determining a final candidate from the set of candidates based on the boundary matching costs; and
encoding or decoding the current block using the final candidate, wherein each of the boundary matching costs is determined for one weighting using the predicted samples of the current block derived according to said one weighting.
15 . The method of claim 14 , wherein a final weighting value corresponding to a smallest boundary matching cost is selected implicitly.
16 . An apparatus for video coding, the apparatus comprising one or more electronics or processors arranged to:
receive input data associated with a current block, wherein the input data comprise pixel data for the current block to be encoded at an encoder side or encoded data associated with the current block to be decoded at a decoder side;
determine a set of candidates associated with coding modes or mode parameters;
determine boundary matching costs associated with the set of candidates, wherein each of the boundary matching costs is determined, for one target candidate of the set of candidates, by using reconstructed or predicted samples of the current block determined according to said one target candidate and neighboring reconstructed or predicted samples of one or more neighboring blocks of the current block, and wherein each of the boundary matching costs is calculated using one target configuration selected from a plurality of configurations;
determine a final candidate from the set of candidates based on the boundary matching costs; and
encode or decode the current block using the final candidate,
wherein each of the boundary matching costs is determined for one weighting using the reconstructed samples of the current block derived according to said one weighting, and a weighting index is signaled at the encoder side or parsed at the decoder side for selecting a final weighting value from re-ordered weightings according to the boundary matching costs.