Patent ID: 9300964
Filing Date: 2016-03-29
CPC Classification: H04N

Claim Text:
1. An image decoding apparatus configured to reconstruct an image from coded data by generating prediction images in terms of luma and chroma through intra-prediction method corresponding to a prediction mode respectively, the image decoding apparatus comprising: a chroma prediction circuit that corrects a prediction direction in a case that chroma prediction image generation is performed in accordance with the prediction mode used in luma prediction image generation with a color format of the image being a 4:2:2 format, wherein the chroma prediction circuit corrects a first prediction mode for use in the luma prediction image generation to a second prediction mode for use in the chroma prediction image generation by referencing a prediction mode conversion table to convert the first prediction mode, wherein the prediction mode conversion table is a table that results in the first prediction mode in luma space and the second prediction mode in chroma space having approximately a same gradient of prediction direction in a coordinate system.