Image processing device and method
The present disclosure relates to an image processing device and method that enable suppression of an increase in the amount of coding of a quantization matrix. An image processing device of the present disclosure includes an up-conversion unit configured to up-convert a quantization matrix limited to a size less than or equal to a transmission size that is a maximum size allowed for transmission, from the transmission size to a size that is identical to a block size that is a processing unit of quantization or dequantization. The present disclosure is applicable to, for example, an image processing device for processing image data.
1. An image processing device, comprising:
a memory; and
processing circuitry configured to:
decode a bit stream to generate quantized data, the bit stream including a first quantization matrix, a second quantization matrix and a third quantization matrix, wherein the first quantization matrix is a first size of 32×32, the second quantization matrix is a second size of 16×16, the third quantization matrix is a third size of 8×8, and the third quantization matrix is extracted from elements of the first quantization matrix;
set the first quantization matrix of the first size, corresponding to a transform unit that is the first size, by performing a nearest neighbor interpolation process onto each element of the third quantization matrix of the third size; and
dequantize the generated quantized data using the set first quantization matrix of the first size.
2. The image processing device according to claim 1 , wherein the second quantization matrix of the second size is included in a picture parameter set of the bit stream.
3. The image processing device according to claim 2 , wherein the processing circuitry is further configured to inverse orthogonal transform, in transformation units of the first size, the transform coefficient data resulted from dequantization to the generated quantized data.
4. An image processing method, comprising:
decoding a bit stream to generate quantized data, the bit stream including a first quantization matrix, a second quantization matrix and a third quantization matrix, wherein the first quantization matrix is a first size of 32×32, the second quantization matrix is a second size of 16×16, the third quantization matrix is a third size of 8×8, and the third quantization matrix is extracted from elements of the first quantization matrix;
setting the first quantization matrix of the first size, corresponding to a transform unit that is the first size, by performing a nearest neighbor interpolation process onto each element of the third quantization matrix of the third size; and
dequantizing the generated quantized data using the set first quantization matrix of the first size.
5. The image processing method according to claim 4 , wherein the second quantization matrix of the second size is included in a picture parameter set of the bit stream.
6. The image processing method according to claim 5 , further comprising:
inverse orthogonal transforming, in transformation units of the first size, the transform coefficient data resulted from dequantization to the generated quantized data.