Granted Patent B2

US 12,744,936 · App. 18/865,941 · Granted Sep 22, 2026

Inventors: Yong Jo Ahn (Seoul, KR); Jong Seok Lee (Seoul, KR); Jin Heo (Yongin-si, KR); Seung Wook Park (Yongin-si, KR)

Assignees: HYUNDAI MOTOR COMPANY; KIA CORPORATION; DIGITALINSIGHTS INC.

H04N19/597H04N19/172H04N19/33H04N19/51

Abstract

Claims (79)

1 . A method of decoding a mesh, performed by a mesh decoding device, the method comprising:

separating a bitstream into a base mesh bitstream, a transform-coefficient bitstream, and an attribute map bitstream, wherein the base mesh bitstream includes a patch bitstream and a sub-base mesh bitstream; and

decoding the base mesh bitstream to reconstruct a base mesh including base mesh vertices and connectivity,

wherein reconstructing the base mesh includes:

decoding the patch bitstream to reconstruct patch information, wherein the patch information includes an offset and a size of each patch;

decoding the sub-base mesh bitstream to reconstruct a patch-based base mesh; and

reconstructing the base mesh vertices and connectivity by using the patch information and the patch-based base mesh.

2 . The method of claim 1 , further comprising:

performing surface split based on the reconstructed base mesh vertices and connectivity to generate predicted vertices and connectivity, wherein the predicted vertices include the reconstructed base mesh vertices and sub-vertices;

decoding the transform-coefficient bitstream based on a video decoding method to reconstruct vector differences of vertices for the mesh;

adding the predicted vertices and vector differences to reconstruct vertices and connectivity; and

decoding the attribute map bitstream based on the video decoding method to reconstruct an attribute map.

3 . The method of claim 2 , wherein generating the predicted vertices and connectivity includes:

performing the surface split based on the base mesh vertices and connectivity to generate a sub-vertex; and

generating connectivity connecting the sub-vertex to the base mesh vertices.

4 . The method of claim 2 , wherein reconstructing the vector differences of the vertices includes:

decoding the transform-coefficient bitstream to reconstruct a transform-coefficient image; and

generating transform-coefficients of the vertices from the transform-coefficient image.

5 . The method of claim 4 , wherein reconstructing the vector differences of the vertices includes:

inversely quantizing the transform-coefficients; and

inversely transforming the inversely quantized transform-coefficients to reconstruct the vector differences of the vertices.

6 . The method of claim 1 , wherein reconstructing the base mesh includes:

separating the base mesh bitstream into the patch bitstream and the sub-base mesh bitstream; and

storing the reconstructed base mesh vertices and connectivity.

7 . The method of claim 1 , wherein reconstructing the base mesh vertices and connectivity includes:

adding the offset to the patch-based base mesh to correct the patch-based base mesh; and

collecting corrected patch-based base meshes in a same space to generate the base mesh vertices and connectivity.

8 . The method of claim 1 , wherein reconstructing the base mesh includes:

decoding the sub-base mesh bitstream to reconstruct a motion vector;

compensating for a motion of base mesh vertices of a previous frame by using the motion vector to reconstruct the base mesh vertices and connectivity; and

storing the reconstructed base mesh vertices and connectivity.

9 . A method of encoding a mesh, performed by a mesh encoding device, the method comprising:

acquiring original vertices and connectivity, and an original attribute map for the mesh;

encoding the original vertices and connectivity to generate a base mesh bitstream; and

generating a reconstructed base mesh including reconstructed base mesh vertices and connectivity from the base mesh bitstream,

wherein generating the base mesh bitstream includes:

downsampling the original vertices and connectivity to generate a base mesh, wherein the base mesh includes base mesh vertices and connectivity;

classifying the base mesh into a plurality of patches by using the base mesh vertices and connectivity and generating patch information of each patch, wherein the patch information includes an offset and a size of each patch; and

subtracting the offset from position coordinate values of the base mesh vertices to generate differential base mesh vertices and connectivity.

10 . The method of claim 9 , further comprising:

performing surface split based on the reconstructed base mesh vertices and connectivity to generate predicted vertices and connectivity, wherein the predicted vertices include the reconstructed base mesh vertices and sub-vertices; and

subtracting the predicted vertices from the original vertices based on the original vertices and connectivity and the predicted vertices and connectivity to generate vector differences.

11 . The method of claim 10 , further comprising:

transforming, quantizing, and packing the vector differences to generate a transform-coefficient image; and

encoding the transform-coefficient image by using a video encoding method to generate a transform-coefficient bitstream.

12 . The method of claim 11 , further comprising:

generating a reconstructed transform-coefficient image from the transform-coefficient bitstream;

unpacking, inversely quantizing, and inversely transforming the reconstructed transform-coefficient image to reconstruct the vector differences; and

adding the predicted vertices and the reconstructed vector differences to reconstruct vertices and connectivity for the mesh.

13 . The method of claim 12 , further comprising:

generating a corrected attribute map by using the original vertices and connectivity, the original attribute map, and the reconstructed vertices and connectivity;

encoding the corrected attribute map by using the video encoding method to generate an attribute map bitstream; and

combining the base mesh bitstream, the transform-coefficient bitstream, and the attribute map bitstream.

14 . The method of claim 9 , wherein generating the base mesh bitstream includes:

encoding the patch information to generate a patch bitstream;

encoding the differential base mesh vertices and connectivity based on a static mesh encoding method to generate a sub-base mesh bitstream; and

combining the patch bitstream and the sub-base mesh bitstream to generate the base mesh bitstream.

15 . The method of claim 9 , wherein generating the reconstructed base mesh includes:

reconstructing the differential base mesh vertices and connectivity from the sub-base mesh bitstream;

adding the reconstructed differential base mesh vertices and the offset to generate the reconstructed base mesh vertices and connectivity; and

storing the reconstructed base mesh vertices and connectivity.

16 . The method of claim 9 , wherein generating the base mesh bitstream includes:

performing motion prediction based on the original vertices and connectivity and reconstructed base mesh vertices and connectivity of a previous frame to generate a motion vector; and

encoding the motion vector to generate the sub-base mesh bitstream.

17 . The method of claim 16 , wherein generating the reconstructed base mesh includes:

decoding the sub-base mesh bitstream to reconstruct the motion vector;

compensating for the motion of the reconstructed base mesh vertices of the previous frame by using the reconstructed motion vector to generate the reconstructed base mesh vertices and connectivity; and

storing the reconstructed base mesh vertices and connectivity.

18 . A method of transmitting a bitstream, the method comprising:

generating the bitstream by a mesh encoding method; and

transmitting the bitstream,

wherein the mesh encoding method comprises:

acquiring original vertices and connectivity, and an original attribute map for mesh;

encoding the original vertices and connectivity to generate a base mesh bitstream; and

generating a reconstructed base mesh including reconstructed base mesh vertices and connectivity from the base mesh bitstream,

wherein generating the base mesh bitstream includes:

downsampling the original vertices and connectivity to generate a base mesh, wherein the base mesh includes base mesh vertices and connectivity;

classifying the base mesh into a plurality of patches using the base mesh vertices and connectivity and generating patch information of each patch, wherein the patch information includes an offset and a size of each patch; and

subtracting the offset from position coordinate values of the base mesh vertices to generate differential base mesh vertices and connectivity.

Assignments (1)

Priority Claims (2)

Continuity (1)

References Cited (14)