Method for processing immersive video and method for producing immersive video
A method for processing an immersive video includes: performing pruning for view images; generating an atlas by packing a patch that is extracted as a result of the pruning; deriving an offset for the patch that is comprised in the atlas; and correcting pixel values in the patch by using the derived offset.
1. A method for processing an immersive video, the method comprising:
performing pruning for view images;
generating a texture atlas by packing a patch extracted as a result of the pruning;
determining an offset for the patch in the texture atlas;
correcting pixel values in the patch by using the offset; and
encoding the patch with corrected pixel values,
wherein a correction of a pixel value in the patch is performed by subtracting the offset from the pixel value in the patch, and
wherein when a value obtained by subtracting the offset from the pixel value is less than a minimum value expressible by a bit-depth, the pixel value is corrected to the minimum value expressible by the bit-depth rather than the value obtained by subtracting the offset from the pixel value.
2. The method of claim 1 , wherein the offset is derived as a difference value between a median value under the bit-depth, and an average value of the pixel values in the patch.
3. The method of claim 1 , wherein, when a value, which obtained by subtracting the offset from the pixel value is greater than a maximum value expressible by the bit-depth, the pixel value is corrected to the maximum value expressible by the bit-depth rather than the value obtained by subtracting the offset from the pixel value.
4. The method of claim 1 , further comprising encoding offset information for the patch as metadata,
wherein the offset information is encoded individually for each of color components, the color components comprising a luminance component and a chrominance component.
5. A method for synthesizing an immersive video, the method comprising:
decoding a texture atlas;
decoding metadata for the texture atlas;
extracting, by using the metadata, a patch from the texture atlas;
decoding an offset for the patch; and
correcting pixel values in the patch extracted from the texture atlas by using the decoded offset,
wherein a correction of a pixel value in the patch is performed by adding the offset to the pixel value in the patch, and
wherein when a value obtained by adding the offset to the pixel value is greater than a maximum value expressible by a bit-depth, the pixel value is corrected to the maximum value expressible by the bit-depth rather than the value obtained by adding the offset to the pixel value.
6. The method of claim 5 , wherein the correction is performed only for the patch derived from the texture atlas, but not for a patch derived from a depth atlas.
7. The method of claim 6 , wherein when a value resulting from adding the offset to the pixel value is less than a minimum value expressible by a bit-depth, the pixel value is corrected to the minimum value expressible by the bit-depth rather than the value derived by adding the offset to the pixel value.
8. The method of claim 5 , wherein:
the offset is signaled as metadata for the patch, and
the offset is signaled individually for each of color components, the color components comprising a luminance component and a chrominance component.