Image processing device and image processing method

1. An image processing device comprising:

a decoding section that generates a decoded image by performing a decoding process of a bitstream; and

a filtering section that applies, as a second color-difference filter having a higher filter strength than a first color-difference filter, a reduced second luminance filter or a reduced first luminance filter to a pixel of a color-difference component located around a block boundary in the decoded image having undergone the decoding process by the decoding section, the reduced second luminance filter having a reduced filter characteristic with respect to a second luminance filter having a higher filter strength than a first luminance filter, the reduced first luminance filter having a reduced filter characteristic with respect to the first luminance filter.

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

the reduced second luminance filter is a reduced second luminance vertical filter that executes the reduced second luminance filter in a vertical direction, and

the second color-difference filter is a second color-difference vertical filter that executes the second color-difference filter in the vertical direction.

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

the reduced second luminance vertical filter is a filter in which a filter coefficient or a clip parameter is changed with respect to the second luminance filter.

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

the reduced second luminance vertical filter is an asymmetric filter in which a filter characteristic of a filter to be applied to a pixel located on an upper side of a block boundary is reduced.

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

the reduced first luminance filter is a reduced first luminance vertical filter that executes the reduced first luminance filter in the vertical direction.

6. The image processing device according to claim 2 , further comprising:

a control section that controls the filtering section such that the reduced second luminance vertical filter is applied, as the second color-difference vertical filter, to a block boundary of a coding tree block of a fixed size by a sequence unit.

7. The image processing device according to claim 6 , wherein

the control section controls the filtering section such that the reduced second luminance vertical filter is applied, as the second color-difference vertical filter, to a block boundary of a block divided from the coding tree block.

8. The image processing device according to claim 6 , wherein

the control section controls the filtering section such that a second luminance vertical filter that executes the second luminance filter in the vertical direction is applied, as the second color-difference vertical filter, to a block boundary of a block divided from the coding tree block.

9. The image processing device according to claim 7 , wherein

the block is divided according to a Quad-Tree Block Structure, a Quad Tree Plus Binary Tree Block Structure, or a Multi-type Tree Coding Block Structure.

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

the second luminance filter is a strong filter for a luminance component conforming to H,265/HEVC standard.

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

the second luminance filter is a filter obtained by changing a filter characteristic of a strong filter for a luminance component conforming to H,265/HEVC standard.

12. An image processing method comprising:

generating a decoded image by performing a decoding process of a bitstream; and

applying, as a second color-difference filter having a higher filter strength than a first color-difference filter, a reduced second luminance filter or a reduced first luminance filter to a pixel of a color-difference component located around a block boundary in the decoded image, the reduced second luminance filter having a reduced filter characteristic with respect to a second luminance filter having a higher filter strength than a first luminance filter, the reduced first luminance filter having a reduced filter characteristic with respect to the first luminance filter.

13. An image processing device comprising:

a filtering section that applies, as a second color-difference filter having a higher filter strength than a first color-difference filter, a reduced second luminance filter or a reduced first luminance filter to a pixel of a color-difference component located around a block boundary in a local decoded image obtained by a local decoding process during an encoding process of an image, the reduced second luminance filter having a reduced filter characteristic with respect to a second luminance filter having a higher filter strength than a first luminance filter, the reduced first luminance filter having a reduced filter characteristic with respect to the first luminance filter; and

an encoding section that performs an encoding process of the image by using the local decoded image to which the second color-difference filter has been applied by the filtering section.

14. An image processing method comprising:

applying, as a second color-difference filter having a higher filter strength than a first color-difference filter, a reduced second luminance filter or a reduced first luminance filter to a pixel of a color-difference component located around a block boundary in a local decoded image obtained by a local decoding process during an encoding process of an image, the reduced second luminance filter having a reduced filter characteristic with respect to a second luminance filter having a higher filter strength than a first luminance filter, the reduced first luminance filter having a reduced filter characteristic with respect to the first luminance filter; and

performing an encoding process of the image by using the local decoded image to which the second color-difference filter has been applied.