Patent ID: 9008186
Filing Date: 2015-04-14
Classification: H04N

Abstract:
1. An image coding method for coding an image, comprising: quantizing a plurality of coefficients included in a plurality of blocks included in the image; and coding coefficient information indicating the plurality of coefficients, and quantization information which is used in the quantizing, wherein the quantization information includes at least one of: (i) a first flag indicating whether or not the plurality of blocks are quantized using a plurality of quantization matrices each having coefficients respectively corresponding to the plurality of coefficients, (ii) a second flag indicating whether or not the plurality of quantization matrices are included in a sequence parameter set, and (iii) a third flag indicating whether or not the plurality of quantization matrices are included in a picture parameter set, and when all of the plurality of blocks are quantized in the quantizing using only a plurality of default matrices as the plurality of quantization matrices, only the following are coded as the quantization information in the coding, indicating that the quantizing is performed using only the plurality of default matrices: (i) the first flag indicating that the plurality of are quantized using the plurality of quantization matrices, (ii) the second flag indicating that the plurality of quantization matrices are not included in the sequence parameter set, and (iii) the third flag indicating that the plurality of quantization matrices are not included in the picture parameter set.