Image processing device and image processing method

1. An image processing device comprising:

a decoder that decodes a bitstream to generate a decoded image; and

a filter that

applies a deblocking filter to a color difference component of pixels near a block boundary of the decoded image generated by the decoder using a color difference offset parameter set used when applying a deblocking filter to the color difference component of pixels near the block boundary of the decoded image generated by the decoder, wherein the pixels near the block boundary of the decoded image are pixels located within a range in which the deblocking filter is applied to the block boundary, and

applies the deblocking filter to a first color difference component and a second color difference component of the pixels near the block boundary of the decoded image generated by the decoder using a first color difference offset parameter set used when applying a deblocking filter to the first color difference component of the decoded image and a second color difference offset parameter set used when applying a deblocking filter to the second color difference component of the decoded image.

2. The image processing device according to claim 1 , wherein

when a color space for the decoded image is YUV,

the first color difference offset parameter set is an offset parameter set used for a U component of the decoded image, and

the second color difference offset parameter set is an offset parameter set used for a V component of the decoded image.

3. The image processing device according to claim 1 , wherein

when a color space for the decoded image is YCbCr,

the first color difference offset parameter set is an offset parameter set used for a Cb component of the decoded image, and

the second color difference offset parameter set is an offset parameter set used for a Cr component of the decoded image.

4. The image processing device according to claim 1 , wherein

the first color difference offset parameter set and the second color difference offset parameter set are set as the syntax of the bitstream, and

the decoder parses the first color difference offset parameter set and the second color difference offset parameter set included in the bitstream.

5. The image processing device according to claim 4 , wherein the syntax is a picture parameter set or a slice header.

6. The image processing device according to claim 4 , wherein the syntax is a picture parameter set and a slice header.

7. The image processing device according to claim 1 , wherein the filter applies the deblocking filter to a luminance component of pixels near the block boundary of the decoded image generated by the decoder using a luminance offset parameter set used when applying a deblocking filter to the luminance component of the decoded image.

8. An image processing method comprising:

decoding a bitstream to generate a decoded image;

applying a deblocking filter to a color difference component of pixels near a block boundary of the decoded image generated by the decoding using a color difference offset parameter set used when applying a deblocking filter to the color difference component of pixels near the block boundary of the decoded image generated by the decoding, wherein the pixels near the block boundary of the decoded image are pixels located within a range in which the deblocking filter is applied to the block boundary; and

applying the deblocking filter to a first color difference component and a second color difference component of the pixels near the block boundary of the decoded image generated by the decoder using a first color difference offset parameter set used when applying a deblocking filter to the first color difference component of the decoded image and a second color difference offset parameter set used when applying a deblocking filter to the second color difference component of the decoded image.

9. An image processing device comprising:

circuitry that sets a color difference offset parameter set used when applying a deblocking filter to a color difference component of a decoded image obtained by decoding a bitstream; and

an encoder that encodes an image to generate the bitstream including the color difference offset parameter set set by the circuitry,

wherein the circuitry sets a first color difference offset parameter set used when applying a deblocking filter to a first color difference component of the decoded image and a second color difference offset parameter set used when applying a deblocking filter to a second color difference component of the decoded image,

the encoder generates the bitstream including the first color difference offset parameter set and the second color difference offset parameter set set by the circuitry,

when a color space for the decoded image is YUV

the first color difference offset parameter set is a parameter set used for a U component of the decoded image, and

the second color difference offset parameter set is a parameter set used for a V component of the decoded image, and

when a color space for the decoded image is YCbCr,

the first color difference offset parameter set is an offset parameter set used for a Cb component of the decoded image, and

the second color difference offset parameter set is an offset parameter set used for a Cr component of the decoded image.

10. The image processing device according to claim 9 , wherein the encoder generates the bitstream including the first color difference offset parameter set and the second color difference offset parameter set set by the circuitry as syntax.

11. The image processing device according to claim 10 , wherein the syntax is a picture parameter set or a slice header.

12. The image processing device according to claim 10 , wherein the syntax is a picture parameter set and a slice header.

13. The image processing device according to claim 9 , wherein

the circuitry sets a luminance offset parameter set used when applying a deblocking filter to a luminance component of the decoded image, and

the encoder generates the bitstream including the luminance offset parameter set set by the circuitry.

14. The image processing device according to claim 9 , further comprising:

a filter that applies a deblocking filter to a color difference component of pixels near the block boundary of a locally decoded image locally decoded when encoding using the color difference offset parameter set to generate a filter image, wherein the encoder encodes the image using the filter image generated by the filter.

15. An image processing method comprising:

setting a color difference offset parameter set used when applying a deblocking filter to a color difference component of a decoded image obtained by decoding a bitstream;

encoding an image to generate a bitstream including the color difference offset parameter set set by the setting;

setting a first color difference offset parameter set used when applying a deblocking filter to a first color difference component of the decoded image and a second color difference offset parameter set used when applying a deblocking filter to a second color difference component of the decoded image; and

generating the bitstream including the first color difference offset parameter set and the second color difference offset parameter set set by the circuitry,

when a color space for the decoded image is YUV,

the first color difference offset parameter set is a parameter set used for a U component of the decoded image, and

the second color difference offset parameter set is a parameter set used for a V component of the decoded image, and

when a color space for the decoded image is YCbCr,

the first color difference offset parameter set is an offset parameter set used for a Cb component of the decoded image, and

the second color difference offset parameter set is an offset parameter set used for a Cr component of the decoded image.