CPC H04N 19/115 (2014.11) [H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/44 (2014.11)] | 8 Claims |
1. A method of decoding a video signal, with a decoding apparatus, comprising:
receiving, with the decoding apparatus, a bitstream including a flag indicating whether to decode a chrominance block based on a luminance block corresponding to the chrominance block and a luminance reference region adjacent to the luminance block;
predicting, with the decoding apparatus, the chrominance block based on the luminance block and the luminance reference region according to the flag; and
reconstructing, with the decoding apparatus, the predicted chrominance block,
wherein the luminance reference region includes a top luminance reference region adjacent to a top boundary of the luminance block and a left luminance reference region adjacent to a left boundary of the luminance block,
wherein the top luminance reference region includes a plurality of horizontal sample lines,
wherein the left luminance reference region includes a plurality of vertical sample lines,
wherein a number of the horizontal sample lines belonging to the top luminance reference region is variably determined based on an availability of the top luminance reference region,
wherein a number of the vertical sample lines belonging to the left luminance reference region is variably determined based on an availability of the left luminance reference region,
wherein a second prediction sample of the predicted chrominance block is obtained based on compensation parameters including a weight and an offset,
wherein the second prediction sample is obtained by multiplying a first prediction sample by the weight and summing the offset,
wherein the first prediction sample is obtained by predicting the luminance block,
wherein the compensation parameters are calculated based on a representative luminance value of a luminance reference region adjacent to the luminance block and a representative chrominance value of chrominance reference region adjacent to the chrominance block,
wherein the representative luminance value is derived to be one or more of average values, minimum values, maximum values or median values of some of samples belonging to the luminance reference region, and
wherein the representative chrominance value is derived from a luminance value of the luminance reference region at a corresponding location.
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