Image processing device and method
The present disclosure relates to an image processing device and method that allow reduction in coding efficiency to be suppressed. A pixel value of a chroma component is predicted by linear prediction from a pixel value of a reference image of a luma component whose pixel location is changed by using a filter, and a prediction image of the chroma component is generated. A chroma component of encoded data in which an image is encoded is decoded by using the generated prediction image. The filter is selected on a basis of information regarding a pixel location of the chroma component and information regarding a color format. The present disclosure is applicable, for example, to an image processing device, an image encoding device, an image decoding device, or the like.
1. An image processing device comprising:
circuitry configured to:
predict a pixel value of a chroma component by linear prediction from a pixel value of a reference image of a luma component whose pixel location is changed by using a filter selected on a basis of information regarding a pixel location of the chroma component, relative to a pixel location of the reference image of the luma component, and information regarding a color format, the filter changing the pixel location of the reference image of the luma component;
generate a prediction image of the chroma component based on the predicted pixel value of the chroma component; and
decode, by using the prediction image, a chroma component of encoded data in which an image is encoded.
2. The image processing device according to claim 1 , wherein the circuitry is configured to select the filter on a basis of linear prediction mode information, the information regarding the pixel location of the chroma component, and the information regarding the color format, the linear prediction mode information including information regarding a mode of the linear prediction.
3. The image processing device according to claim 1 , wherein the circuitry is further configured to
change the pixel location of the reference image of the luma component by using the selected filter
predict the pixel value of the chroma component by linear prediction from the pixel value of the reference image of the luma component whose location is changed, and
generate the prediction image of the chroma component.
4. The image processing device according to claim 1 , wherein
the chroma component includes a Cb component and a Cr component, and
the circuitry is further configured to correct a prediction image of the Cr component by using a collocate block of the Cb component, and the prediction image of the Cr component, the collocate block corresponding to the prediction image of the Cr component.
5. The image processing device according to claim 1 , wherein
the circuitry is configured to
acquire the information regarding the pixel location of the chroma component included in the encoded data, and
generate the prediction image of the chroma component by the linear prediction by using the pixel value of the reference image of the luma component whose pixel location is changed on a basis of the information regarding the pixel location of the chroma component, the acquired information regarding the pixel location of the chroma component.
6. The image processing device according to claim 1 , wherein the circuitry is configured to acquire cross-chroma residual prediction information indicating whether to correct a prediction image of a Cr component by using a collocate block of a Cb component corresponding to the prediction image of the Cr component, the cross-chroma residual prediction information being included in the encoded data.
7. An image processing method comprising:
selecting a filter on the basis of the information regarding a pixel location of a chroma component, relative to a pixel location of a reference image of a luma component, and information regarding color format, the filter changing the pixel location of the reference image of the luma component;
predicting a pixel value of the chroma component by linear prediction from a pixel value of the reference image of the luma component whose pixel location is changed by using the filter, and generating a prediction image of the chroma component; and
decoding, by using the generated prediction image, a chroma component of encoded data in which an image is encoded.
8. An image processing device comprising:
circuitry configured to:
predict a pixel value of a chroma component of an image by linear prediction from a pixel value of a reference image of a luma component of the image at a pixel location determined using a filter selected on a basis of information regarding a pixel location of the chroma component, relative to a pixel location of the reference image of the luma component and information regarding a color format of the image;
generate a prediction image of the chroma component; and
encode, by using the prediction image, a chroma component of the image.
9. The image processing device according to claim 8 , wherein the circuitry is configured to:
change the pixel location of the reference image of the luma component by using the filter,
predict the pixel value of the chroma component by linear prediction from the pixel value of the reference image of the luma component whose location is changed, and
generate the prediction image of the chroma component.
10. The image processing device according to claim 8 , wherein
the chroma component includes a Cb component and a Cr component, and
the circuitry is configured to correct a prediction image of the Cr component by using a collocate block of the Cb component, the collocate block corresponding to the prediction image of the Cr component.
11. The image processing device according to claim 8 , wherein the circuitry is configured to add cross-chroma residual prediction information to encoded data, the cross-chroma residual prediction information indicating whether to correct a prediction image of a Cr component by using a collocate block of a Cb component corresponding the prediction image of the Cr component.
12. The image processing device according to claim 11 , wherein the circuitry is configured to add cross-chroma residual prediction enabled information to the encoded data, and adds the cross-chroma residual prediction information to the encoded data in a case where the cross-chroma residual prediction enabled information indicates that the cross-chroma residual prediction information is enabled, the cross-chroma residual prediction enabled information indicating whether or not the cross-chroma residual prediction information is enabled.
13. An image processing method comprising:
selecting a filter on the basis of the information regarding a pixel location of a chroma component, relative to a pixel location of a reference image of a luma component, and information regarding color format, the filter changing the pixel location of the reference image of the luma component;
predicting a pixel value of the chroma component by linear prediction from a pixel value of the reference image of the luma component whose pixel location is changed by using the filter, and generating a prediction image of the chroma component; and
encoding, by using the generated prediction image, a chroma component of an image.