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:
circuitry configured to
decode a bit stream including image data and a first 8×8 quantization matrix corresponding to an 8×8 transform unit, a second 8×8 quantization matrix associated with a 16×16 quantization matrix corresponding to a 16×16 transform unit, and a third 8×8 quantization matrix, different from the second 8×8 quantization matrix, associated with a 32×32 quantization matrix corresponding to a 32×32 transform unit to generate quantized image data;
set a 16×16 quantization matrix from the second 8×8 quantization matrix in a case where an inverse orthogonal transform is to be performed using the 16×16 transform unit and set a 32×32 quantization matrix from the third 8×8 quantization matrix in a case where the inverse orthogonal transform is to be performed using the 32×32 transform unit; and
dequantize the generated quantized image data using the set 16×16 quantization matrix or the set 32×32 quantization matrix.
2. The image processing device according to claim 1 , wherein the circuitry sets the 16×16 quantization matrix by performing an interpolation process on a matrix element in the second 8×8 quantization matrix.
3. The image processing device according to claim 2 , wherein the circuitry sets the 16×16 quantization matrix by performing a nearest neighbor interpolation process on a matrix element in the second 8×8 quantization matrix.
4. The image processing device according to claim 3 , wherein
the circuitry dequantizes the generated quantized image data using the set 32×32 quantization matrix.
5. The image processing device according to claim 4 , wherein the circuitry sets the 32×32 quantization matrix by performing an interpolation process on a matrix element in the third 8×8 quantization matrix.
6. The image processing device according to claim 5 , wherein the circuitry sets the 32×32 quantization matrix by performing a nearest neighbor interpolation process on a matrix element in the third 8×8 quantization matrix.
7. The image processing device according to claim 1 , wherein the circuitry dequantizes the generated quantized image data using the first 8×8 quantization matrix in a case where an inverse orthogonal transform is to be performed using the 8×8 transform unit.
8. The image processing device according to claim 7 , wherein the first 8×8 quantization matrix, the second 8×8 quantization matrix, and the third 8×8 quantization matrix are included in a picture parameter set of the bit stream.
9. The image processing device according to claim 8 , wherein the circuitry is further configured to perform an inverse orthogonal transform on a transform coefficient data obtained by dequantizing the quantized image data, using the 8×8 transform unit, the 16×16 transform unit, or the 32×32 transform unit.
10. An image processing method comprising:
decoding a bit stream including a first 8×8 quantization matrix corresponding to an 8×8 transform unit, a second 8×8 quantization matrix associated with a 16×16 quantization matrix corresponding to a 16×16 transform unit, and a third 8×8 quantization matrix, different from the second 8×8 quantization matrix, associated with a 32×32 quantization matrix corresponding to a 32×32 transform unit to generate quantized image data;
setting a 16×16 quantization matrix from the second 8×8 quantization matrix in a case where an inverse orthogonal transform is to be performed using the 16×16 transform unit and setting a 32×32 quantization matrix from the third 8×8 quantization matrix in a case where the inverse orthogonal transform is to be performed using the 32×32 transform unit; and
dequantizing the generated quantized image data using the set 16×16 quantization matrix or the set 32×32 quantization matrix.