Patent ID: 11949903
Assignee: SUN PATENT TRUST
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. An image coding method for coding a current block, the image coding method comprising:
encoding information in a slice header indicative of a maximum number of merging candidates, wherein the slice header corresponds to a slice containing a plurality of blocks including the current block;
deriving a plurality of merging candidates for encoding the current block from a corresponding plurality of blocks that are neighbor or co-located blocks of the current block, each of the plurality of merging candidates having a motion vector for encoding a corresponding one of the plurality of blocks, a prediction direction that corresponds to the corresponding one of the plurality of blocks, and a reference picture index that identifies a reference picture corresponding to the corresponding one of the plurality of blocks;
determining whether a number of the plurality of merging candidates is less than the maximum number of merging candidates;
when it is determined that the number of the plurality of merging candidates is less than the maximum number of merging candidates, deriving at least one combined candidate for bi-directional prediction, by:
assigning, the motion vector and the reference picture index of a first merging candidate of the plurality of merging candidates, to a first prediction direction of the at least one combined candidate, and
assigning, the motion vector and the reference picture index of a second merging candidate of the plurality of merging candidates, to a second prediction direction of the at least one combined candidate;

selecting a candidate from the plurality of merging candidates and the at least one combined candidate;
encoding an index corresponding to the selected candidate, wherein the maximum number of merging candidates is used to encode the index;
encoding the current block by using the selected candidate; and
decoding the information from the slice header indicative of the maximum number of merging candidates;
deriving the plurality of merging candidates for decoding the current block;
determining whether the number of the plurality of merging candidates for decoding the current block is less than the maximum number of merging candidates;
when it is determined that the number of the plurality of merging candidates is less than the maximum number of merging candidates, deriving the combined merging candidate for bi-directional prediction for decoding the current block, by:
assigning the motion vector and the reference picture index of the first merging candidate of the plurality of merging candidates to the first prediction direction of the combined merging candidate; and
assigning the motion vector and the reference picture index of a second merging candidate of the plurality of merging candidates, to the second prediction direction of the combined merging candidate; and

decoding the current block using the candidate selected from the plurality of merging candidates and the combined merging candidate.