Decoded tile hash SEI message for V3C/V-PCC
A new hash Supplemental Enhancement Information (SEI) message for the V3C/V-PCC atlas frame is described herein. The message is used to signal the hash values that are computed for the syntax elements associated with each patch. The hash SEI message is able to be used for the V3C/V-PCC tile level and optionally for atlas level conformance testing. The hash is able to be used to confirm that the decoded values by the decoder are the same as the original values that were encoded by the encoder.
1. A method comprising:
encoding point cloud content to generate encoded point cloud content;
generating hash information for an atlas, wherein generating the hash information includes combining values of syntax elements of the atlas comprising a frame width of the atlas, a frame height of the atlas and variable values and applying a hash algorithm to the combined values of syntax elements, wherein the hash algorithm is selected based on a defined variable using a lookup table to store multiple hash algorithms;
sending the hash information;
decoding the encoded point cloud content; and
verifying the decoded content using the hash information.
2. The method of claim 1 wherein encoding the point cloud content includes using a V-PCC encoding implementation which compresses point clouds based on projection from 3D to 2D, wherein encoding the point cloud content includes mapping the 3D point cloud data into several 2D patches and arranging the patches into the atlas, which is subsequently encoded with a video encoder, wherein atlas images correspond to geometry of points, respective texture, and an occupancy map that indicates which positions are to be considered for point cloud reconstruction.
3. The method of claim 1 wherein the hash information is sent for a block to patch of the atlas.
4. The method of claim 1 wherein the hash information is sent for a tile.
5. The method of claim 1 wherein the hash information is sent for a block to patch of a tile.
6. The method of claim 1 wherein the hash information is sent in a Supplemental Enhancement Information (SEI) message.
7. The method of claim 6 wherein the SEI message includes tile-based “BlockToPatchMap[ ][ ]” hash value information.
8. The method of claim 1 wherein the hash information is generated using an implementation selected from the group consisting of MD5, CRC and checksum.
9. An apparatus comprising:
a non-transitory memory for storing an application, the application for:
receiving encoded point cloud content;
receiving hash information for an atlas, wherein the hash information includes combined values of syntax elements of the atlas comprising a frame width of the atlas, a frame height of the atlas and variable values and applying a hash algorithm to the combined values of syntax elements, wherein the hash algorithm is selected based on a defined variable using a lookup table to store multiple hash algorithms;
decoding the encoded point cloud content; and
verifying the decoded content using the hash information; and
a processor coupled to the memory, the processor configured for processing the application.
10. The apparatus of claim 9 wherein the hash information is sent for a block to patch of the atlas.
11. The apparatus of claim 9 wherein the hash information is sent for a tile.
12. The apparatus of claim 9 wherein the hash information is sent for a block to patch of a tile.
13. The apparatus of claim 9 wherein the hash information is sent in a Supplemental Enhancement Information (SEI) message.
14. The apparatus of claim 13 wherein the SEI message includes tile-based “BlockToPatchMap[ ][ ]” hash value information.
15. The apparatus of claim 9 wherein the hash information is generated using an implementation selected from the group consisting of MD5, CRC and checksum.
16. A system comprising:
one or more cameras for acquiring three dimensional content;
an encoder for:
encoding the three dimensional content to generate encoded point cloud content; and
generating hash information for an atlas, wherein generating the hash information includes combining values of syntax elements of the atlas comprising a frame width of the atlas, a frame height of the atlas and variable values and applying a hash algorithm to the combined values of syntax elements, wherein the hash algorithm is selected based on a defined variable using a lookup table to store multiple hash algorithms;
sending the hash information; and
a decoder for:
decoding the encoded point cloud content; and
verifying the decoded content using the hash information.
17. The system of claim 16 wherein encoding the three dimensional content includes using a V-PCC encoding implementation which compresses three dimensional content based on projection from 3D to 2D, wherein encoding the three dimensional content includes mapping the 3D point cloud data into several 2D patches and arranging the patches into the atlas, which is subsequently encoded with a video encoder, wherein atlas images correspond to geometry of points, respective texture, and an occupancy map that indicates which positions are to be considered for point cloud reconstruction.
18. The system of claim 16 wherein the hash information is sent for a block to patch of the atlas.
19. The system of claim 16 wherein the hash information is sent for a tile.
20. The system of claim 16 wherein the hash information is sent for a block to patch of a tile.
21. The system of claim 16 wherein the hash information is sent in a Supplemental Enhancement Information (SEI) message.
22. The system of claim 21 wherein the SEI message includes tile-based “BlockToPatchMap[ ][ ]” hash value information.
23. The system of claim 16 wherein the hash information is generated using an implementation selected from the group consisting of MD5, CRC and checksum.