Local illumination compensation
Methods are provided for optical flow-based motion refinement. An exemplary method includes: receiving a bitstream; and decoding, using coded information of the bitstream, one or more pictures, wherein the decoding includes: determining whether a current block is coded by partitioning into multiple parts; and in response to the current block being partitioned into multiple parts that are inter predicted according to respective reference blocks, determining whether to apply a local illumination compensation (LIC) process to the multiple parts based on whether a coded block applies the LIC process.
1 . A method of decoding a bitstream to output one or more pictures for a video stream, the method comprising:
receiving a bitstream; and
decoding, using coded information of the bitstream, one or more pictures,
wherein the decoding comprises:
determining whether a current block of a current picture is coded by partitioning into two geometric partitioning mode (GPM) partitioning parts;
in response to the current block being partitioned into two GMP partitioning parts, determining whether to apply a local illumination compensation (LIC) process to a target GPM partitioning part of the two GPM partitioning parts based on whether a causally neighboring block of the current block applies the LIC process; and
in response to a determination that applying the LIC process to the target GPM partitioning part, deriving LIC parameters from the causally neighboring block.
2 . The method of claim 1 , wherein the causally neighboring block is a block corresponding to a merge index of the target GPM partitioning part.
3 . The method of claim 1 , wherein the decoding further comprises:
storing, for a subblock comprising the target GPM partitioning part, the LIC parameters of the target GPM partitioning part.
4 . The method of claim 1 , wherein the target GPM partitioning part is uni-predicted or bi-predicted.
5 . The method of claim 1 , wherein the decoding further comprises:
in response to a determination that applying the LIC process to the target GPM partitioning part and the target GPM partitioning part being bi-predicted, skipping decoder-side motion vector refinement (DMVR) or bi-directional optical flow (BDOF) towards the target GPM partitioning part.
6 . The method of claim 1 , wherein the decoding further comprises:
inheriting a LIC flag from the causally neighboring block for GPM Template Matching (TM) or GPM split mode reorder towards the target GPM partitioning part.
7 . The method of claim 1 , wherein the current block is a GPM intra inter mode coded block.
8 . The method of claim 1 , wherein the current picture is coded with an angular weighted prediction (AWP) mode.
9 . A method of encoding a video sequence into a bitstream, the method comprising:
receiving a video sequence;
encoding one or more pictures of the video sequence; and
generating a bitstream,
wherein the encoding comprises:
determining whether a current block of a current picture is coded by partitioning into two geometric partitioning mode (GPM) partitioning parts;
in response to the current block being partitioned into two GMP partitioning parts, determining whether to apply a local illumination compensation (LIC) process to a target GPM partitioning part of the two GPM partitioning parts based on whether a causally neighboring block of the current block applies the LIC process; and
in response to a determination that applying the LIC process to the target GPM partitioning part, deriving LIC parameters from the causally neighboring block.
10 . A method for signaling a bitstream, the method comprising:
receiving a video sequence;
encoding the video sequence by:
determining whether a current block of a current picture is coded by partitioning into two geometric partitioning mode (GPM) partitioning parts;
in response to the current block being partitioned into two GPM partitioning parts, determining whether to apply a local illumination compensation (LIC) process to a target GPM partitioning part of the two GPM partitioning parts based on whether a causally neighboring block of the current block applies the LIC process; and
in response to a determination that applying the LIC process to the target GPM partitioning part, deriving LIC parameters from the causally neighboring block;
signaling a bitstream that is generated based on the encoding.
11 . The method of claim 9 , wherein the causally neighboring block is a block corresponding to a merge index of the target GPM partitioning part.
12 . The method of claim 9 , wherein the target GPM partitioning part is uni-predicted or bi-predicted.
13 . The method of claim 9 , wherein the encoding further comprises:
inheriting a LIC flag from the causally neighboring block for GPM Template Matching (TM) or GPM split mode reorder towards the target GPM partitioning part.
14 . The method of claim 9 , wherein the current block is a GPM intra inter mode coded block.
15 . The method of claim 9 , wherein the encoding further comprises:
storing, for a subblock comprising the target GPM partitioning part, the LIC parameters of the target GPM partitioning part.
16 . The method of claim 10 , wherein the causally neighboring block is a block corresponding to a merge index of the target GPM partitioning part.
17 . The method of claim 10 , wherein the target GPM partitioning part is uni-predicted or bi-predicted.
18 . The method of claim 10 , wherein the encoding further comprises:
inheriting a LIC flag from the causally neighboring block for GPM Template Matching (TM) or GPM split mode reorder towards the target GPM partitioning part.
19 . The method of claim 10 , wherein the current block is a GPM intra inter mode coded block.
20 . The method of claim 10 , wherein the encoding further comprises:
storing, for a subblock comprising the target GPM partitioning part, the LIC parameters of the target GPM partitioning part.