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
set a first 8×8 quantization matrix corresponding to an 8×8 transform unit, set a 16×16 quantization matrix from an associated second 8×8 quantization matrix in a case where an orthogonal transform is to be performed using a 16×16 transform unit, and set a 32×32 quantization matrix from an associated third 8×8 quantization matrix, different from the second 8×8 quantization matrix, in a case where the orthogonal transform is to be performed using a 32×32 transform unit; and
quantize transform coefficient data using the set 16×16 quantization matrix or the set 32×32 quantization matrix to generate quantized transform coefficient data; and
encode the quantized transform coefficient data to generate a bit stream including the first 8×8 quantization matrix, the second 8×8 quantization matrix corresponding to the 16×16 transform unit, and the third 8×8 quantization matrix corresponding to the 32×32 transform unit.
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 1 , wherein
the circuitry quantizes the transform coefficient 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 quantizes the transform coefficient data using the first 8×8 quantization matrix in a case where an orthogonal transform is to be performed using an 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 orthogonal transform on image data, using the 8×8 transform unit, the 16×16 transform unit, or the 32×32 transform unit, to generate the transform coefficient data.
10. An image processing method comprising:
setting a first 8×8 quantization matrix corresponding to an 8×8 transform unit, setting a 16×16 quantization matrix from an associated second 8×8 quantization matrix in a case where an orthogonal transform is to be performed using a 16×16 transform unit, and setting a 32×32 quantization matrix from an associated third 8×8 quantization matrix, different from the second 8×8 quantization matrix, in a case where the orthogonal transform is to be performed using a 32×32 transform unit; and
quantizing transform coefficient data using the set 16×16 quantization matrix or the set 32×32 quantization matrix to generate quantized transform coefficient data; and
encoding the quantized transform coefficient data to generate a bit stream including the first 8×8 quantization matrix, the second 8×8 quantization matrix corresponding to the 16×16 transform unit, and the third 8×8 quantization matrix corresponding to the 32×32 transform unit.
11. The image processing method according to claim 10 , wherein the setting the 16×16 quantization matrix includes performing an interpolation process on a matrix element in the second 8×8 quantization matrix.
12. The image processing method according to claim 11 , wherein the setting the 16×16 quantization matrix includes performing a nearest neighbor interpolation process on a matrix element in the second 8×8 quantization matrix.
13. The image processing method according to claim 12 , wherein
the quantizing the transform coefficient data includes using the set 32×32 quantization matrix.
14. The image processing method according to claim 13 , wherein the setting the 32×32 quantization matrix includes performing an interpolation process on a matrix element in the third 8×8 quantization matrix.
15. The image processing method according to claim 14 , wherein the setting the 32×32 quantization matrix includes performing a nearest neighbor interpolation process on a matrix element in the third 8×8 quantization matrix.
16. The image processing method according to claim 10 , wherein the quantizing the transform coefficient data includes using the first 8×8 quantization matrix in a case where an orthogonal transform is to be performed using an 8×8 transform unit.
17. The image processing method according to claim 16 , 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.
18. The image processing method according to claim 17 , wherein the method further includes performing an orthogonal transform on image data, using the 8×8 transform unit, the 16×16 transform unit, or the 32×32 transform unit, to generate the transform coefficient data.