CPC H04N 19/137 (2014.11) [H04N 19/105 (2014.11); H04N 19/132 (2014.11); H04N 19/176 (2014.11)] | 9 Claims |
1. An image decoding method performed by a decoding apparatus, the method comprising:
deriving reference subblocks on a collocated reference picture for subblocks of a current block;
deriving motion information for the subblocks of the current block based on motion information for the reference subblocks;
generating prediction samples based on the motion information for the subblocks of the current block; and
generating reconstructed samples based on the prediction samples,
wherein for a reference subblock in which a motion vector is not available among the reference subblocks, base motion information is derived, and
wherein the base motion information is used as the motion information for a subblock of the current block corresponding to the reference subblock,
wherein the base motion information is derived based on one of the reference subblocks in a reference block located corresponding to the current block on the collocated reference picture,
wherein the base motion information is derived based on a first reference subblock having an initially available motion vector, by checking whether a motion vector is available according to a determined order with respect to the reference subblocks in the reference block, and
wherein, based on the base motion information being not derived, a subblock-based temporal motion vector prediction (sbTMVP) is specified as available.
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