Patent ID: 8938003
Filing Date: 2015-01-20
Classification: H04N

Abstract:
1. A picture coding device that performs intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and codes information relating to an intra prediction mode, the picture coding device comprising: a luma signal intra prediction unit configured to set first to fourth prediction blocks of luma signals acquired by partitioning the luma signals of a minimal coding block horizontally and vertically and predict a luma signal based on a coded neighboring block of the luma signals in accordance with first to fourth luma intra prediction modes derived based on information relating to luma intra prediction modes for prediction blocks of the luma signals respectively in a case where a partition mode in which the luma signals are partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in units of minimal coding blocks set in advance; a chroma signal intra prediction unit configured to set a prediction block of the chroma signals without partitioning the chroma signals of the minimal coding block and predict a chroma signal based on a coded neighboring block of the chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set, and a chroma format is 4:2:0 the chroma intra prediction mode being derived based on information relating to a chroma intra prediction mode and the first luma intra prediction mode; and a bitstream constructing unit configured to code information relating to the prediction mode of the minimal coding block and construct a bitstream in which information relating to prediction modes is arranged in order of, within the minimal coding block, a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals, wherein the luma signal intra prediction unit, the chroma signal intra prediction unit, and the bitstream constructing unit are implemented using hardware, memory storing firmware, or a computer with software.