Patent ID: 9667974
Date: 2017-05-30
CPC Classifications: H04N

Claim:
1. A method of decoding an image, the method comprising: obtaining first information that indicates an intra prediction mode of a luminance block from a bitstream; obtaining second information that indicates an intra prediction mode of a chrominance block corresponding to the luminance block from the bitstream; performing intra prediction on the luminance block based on the intra prediction mode of the luminance block; and performing intra prediction on the chrominance block based on the intra prediction mode of the chrominance block, wherein the intra prediction mode of the luminance block includes a particular direction among a plurality of directions and the particular direction is indicated by one of a dx number in a horizontal direction and a fixed number in a vertical direction, and a dy number in the vertical direction and a fixed number in the horizontal direction, wherein the performing intra prediction on the luminance block comprises: wherein, when the second information indicates that the intra prediction mode of the chrominance block is equal to the intra prediction mode of the luminance block, the intra prediction mode of the chrominance block is determined to be equal to the intra prediction mode of the luminance block.