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 quantization matrix corresponding to a first transform unit of first unit size, a second quantization matrix corresponding to a second transform unit of second unit size larger than the first unit size, and a third quantization matrix, different from the second quantization matrix, corresponding to a third transform unit of third unit size larger than the first unit size to generate quantized image data;
set a fourth quantization matrix from the second quantization matrix in a case where an inverse orthogonal transform is to be performed using the second transform unit and set a fifth quantization matrix from the third quantization matrix in a case where the inverse orthogonal transform is to be performed using the third transform unit; and
dequantize the generated quantized image data using the set fourth quantization matrix or the set fifth quantization matrix.
2. The image processing device according to claim 1 , wherein the circuitry sets the fourth quantization matrix by performing an interpolation process on a matrix element in the second quantization matrix.
3. The image processing device according to claim 2 , wherein the circuitry sets the fourth quantization matrix by performing a nearest neighbor interpolation process on a matrix element in the second quantization matrix.
4. The image processing device according to claim 3 , wherein the circuitry dequantizes the generated quantized image data using the set fifth quantization matrix.
5. The image processing device according to claim 4 , wherein the circuitry sets the fifth quantization matrix by performing an interpolation process on a matrix element in the third quantization matrix.
6. The image processing device according to claim 5 , wherein the circuitry sets the fifth quantization matrix by performing a nearest neighbor interpolation process on a matrix element in the third quantization matrix.
7. The image processing device according to claim 1 , wherein the circuitry dequantizes the generated quantized image data using the first quantization matrix in a case where an inverse orthogonal transform is to be performed using the first transform unit.
8. The image processing device according to claim 7 , wherein the first quantization matrix, the second quantization matrix, and the third 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 first transform unit, the second transform unit, or the third transform unit.
10. An image processing method comprising:
decoding a bit stream including image data and a first quantization matrix corresponding to a first transform unit of first unit size, a second quantization matrix corresponding to a second transform unit of second unit size larger than the first unit size, and a third quantization matrix, different from the second quantization matrix, corresponding to a third transform unit of third unit size larger than the first unit size to generate quantized image data;
setting a fourth quantization matrix from the second quantization matrix in a case where an inverse orthogonal transform is to be performed using the second transform unit and setting a fifth quantization matrix from the third quantization matrix in a case where the inverse orthogonal transform is to be performed using the third transform unit; and
dequantizing the generated quantized image data using the set fourth quantization matrix or the set fifth quantization matrix.
11. The image processing method according to claim 10 , further comprising setting the fourth quantization matrix by performing an interpolation process on a matrix element in the second quantization matrix.
12. The image processing method according to claim 11 , further comprising setting the fourth quantization matrix by performing a nearest neighbor interpolation process on a matrix element in the second quantization matrix.
13. The image processing method according to claim 12 , further comprising dequantizing the generated quantized image data using the set fifth quantization matrix.
14. The image processing method according to claim 13 , further comprising setting the fifth quantization matrix by performing an interpolation process on a matrix element in the third quantization matrix.
15. The image processing method according to claim 14 , further comprising setting the fifth quantization matrix by performing a nearest neighbor interpolation process on a matrix element in the third quantization matrix.
16. The image processing method according to claim 10 , further comprising dequantizing the generated quantized image data using the first quantization matrix in a case where an inverse orthogonal transform is to be performed using the first transform unit.
17. The image processing method according to claim 16 , wherein the first quantization matrix, the second quantization matrix, and the third quantization matrix are included in a picture parameter set of the bit stream.
18. The image processing method according to claim 17 , further comprising performing an inverse orthogonal transform on a transform coefficient data obtained by dequantizing the quantized image data, using the first transform unit, the second transform unit, or the third transform unit.