Granted Patent B2

US 12,225,197 · App. 18/126,082 · Granted Feb 11, 2025

Inventors: Hui Yuan (Dongguan, CN); Xiaohui Wang (Dongguan, CN); Ming Li (Dongguan, CN); Lu Wang (Dongguan, CN); Qi Liu (Dongguan, CN)

Assignee: GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.

H04N19/124H04N19/14H04N19/176

Abstract

Claims (77)

1. A method for point cloud encoding, comprising:

partitioning a point cloud, and determining a current coding block;

determining a quantization parameter optimization enable identifier, a hierarchical level index, and a quantization parameter offset parameter of the current coding block;

determining, according to the hierarchical level index and the quantization parameter offset parameter, a quantization step Qstep corresponding to a level of detail (LOD); and

upon detecting that the quantization parameter optimization enable identifier is a first value, performing the following operations for one or more points included in the current coding block;

determining an LOD i where a currently processed point P i is located;

predicting the point P i according to the LOD i to obtain a prediction value of the point P i ;

determining a quantization step Qstep i which is adaptive to the LOD i ;

determining, according to the prediction value of the point P i and an original value of the point P i , a residual of the point P i ;

quantizing the residual of the point P i according to the quantization step Qstep i to obtain a quantized residual of the point P i ; and

encoding and signalling the quantization parameter optimization enable identifier.

2. The method of claim 1 , wherein the determining a quantization parameter optimization enable identifier, a hierarchical level index, and a quantization parameter offset parameter of the current coding block comprises:

acquiring coding parameters of the current coding block; and

determining the quantization parameter optimization enable identifier, the hierarchical level index, and the quantization parameter offset parameter in the coding parameters.

3. The method of claim 1 , wherein the bitstream comprises a bitstream of parameter set, wherein the parameter set is used for decoding data of one or more point clouds at different times, the data is attribute data; and the parameter set is an attribute parameter set.

4. The method of claim 1 , wherein the determining a quantization step Qstep i which is adaptive to the LOD i comprises:

querying a quantization step lookup table according to a hierarchical level index of the LOD i to determine the quantization step Qstep i corresponding to the LOD i , wherein the quantization step lookup table comprises a corresponding relationship between LODs and quantization step Qsteps.

5. The method of claim 4 , wherein the determining, according to the hierarchical level index and the quantization parameter offset parameter, a quantization parameter offset of the LOD comprises:

determining, according to a hierarchical level index corresponding to a level combination which a currently processed LOD is in, a hierarchical level index of the currently processed LOD; and

querying, according to the hierarchical level index of the currently processed LOD, the quantization parameter offset parameter to determine a quantization parameter offset corresponding to the quantization parameter offset parameter.

6. The method of claim 1 , wherein the determining, according to the hierarchical level index and the quantization parameter offset parameter, a quantization step Qstep i corresponding to the LOD i comprises:

determining a quantization parameter Qp i ;

determining, according to the hierarchical level index and the quantization parameter offset parameter, a quantization parameter offset of each LOD i ; and

determining, according to the quantization parameter Qp i and the quantization parameter offset of each LOD i , a quantization step Qstep i corresponding to each LOD i .

7. The method of claim 6 , wherein the determining, according to the hierarchical level index and the quantization parameter offset parameter, a quantization parameter offset of each LOD i comprises:

determining whether a currently processed LOD belongs to a level range restrained by the hierarchical level index, wherein the level range comprises first N levels of a plurality of LODs, and N is a positive integer less than or equal to a first threshold value;

if yes, determining a value j of the quantization parameter offset of the currently processed LOD according to the quantization parameter offset parameter, wherein j is an integer greater than 0 and less than or equal to a second threshold value; and

if not, determining the value of the quantization parameter offset of the currently processed LOD as 0.

8. The method of claim 7 , wherein when the quantization parameter Qp i is greater than or equal to a third threshold value, then j is a first preset value; and

when the quantization parameter Qp i is less than the third threshold value, then j is a second preset value.

9. A method for point cloud decoding, comprising:

performing the following operations for one or more points included in a current coding block:

determining an LOD i where a currently processed point P i is located;

predicting the point P i according to the LOD i to obtain a prediction value of the point P i ;

determining a quantization step Qstep i which is adaptive to the LOD i , comprising:

determining the quantization step Qstep i which is adaptive to the LOD i according to a hierarchical level index and quantization parameter offset parameter corresponding to the current coding block;

determining a quantized residual of the point P i ;

performing inverse quantization on the quantized residual of the point P i according to the quantization step Qstep; to obtain a reconstructed residual of the point P i ; and

determining a reconstructed value of the point P i according to the reconstructed residual of the point P i and the prediction value of the point P i .

10. The method of claim 9 , wherein before determining the quantization step Qstep i which is adaptive to the LOD i according to the hierarchical level index and quantization parameter offset parameter corresponding to the current coding block, further comprising:

determining a value of a quantization parameter optimization enable identifier of the current coding block;

if the value of the quantization parameter optimization enable identifier is a first value, determining the hierarchical level index and the quantization parameter offset parameter corresponding to the current coding block; and

determining a quantization step Qstep corresponding to the LOD according to the hierarchical level index and the quantization parameter offset parameter.

11. The method of claim 10 , wherein the determining a value of a quantization parameter optimization enable identifier of the current coding block comprises:

parsing a bitstream, and determining the value of the quantization parameter optimization enable identifier in a parameter set of the current coding block.

12. The method of claim 11 , wherein the parameter set is an attribute parameter set, wherein the determining the hierarchical level index and the quantization parameter offset parameter of the current coding block comprises:

determining the hierarchical level index and the quantization parameter offset parameter in the attribute parameter set.

13. The method of claim 9 , wherein the determining a quantization step Qstep i which is adaptive to the LOD i comprises:

querying a quantization step lookup table according to the hierarchical level index of the LOD i to determine the quantization step Qstep i corresponding to the LOD i , wherein the quantization step lookup table comprises a corresponding relationship between LODs and quantization step Qsteps.

14. The method of claim 9 , wherein the determining a quantization step Qstep; corresponding to the LOD i according to the hierarchical level index and the quantization parameter offset parameter comprises:

determining a quantization parameter Qp i ;

determining a quantization parameter offset of each LOD i according to the hierarchical level index and the quantization parameter offset parameter; and

determining a quantization step Qstep i corresponding to each LOD i according to the quantization parameter Qp i and the quantization parameter offset of each LOD i .

15. The method of claim 14 , wherein the determining a quantization parameter offset of each LOD i according to the hierarchical level index and the quantization parameter offset parameter comprises:

determining whether a currently processed LOD belongs to a level range restrained by the hierarchical level index, wherein the level range comprises first N levels of a plurality of LODs, and N is a positive integer less than or equal to a first threshold value;

if yes, determining a value j of the quantization parameter offset of the currently processed LOD according to the quantization parameter offset parameter, wherein j is an integer greater than 0 and less than or equal to a second threshold value; and

if not, determining the value of the quantization parameter offset of the currently processed LOD as 0.

16. The method of claim 15 , wherein when the quantization parameter Qp i is greater than or equal to a third threshold value, then j is a first preset value; and

when the quantization parameter Qp i is less than the third threshold value, then j is a second preset value.

17. The method of claim 14 , wherein the determining a quantization parameter offset of each LOD according to the hierarchical level index and the quantization parameter offset parameter comprises:

determining, according to a hierarchical level index corresponding to a level combination which a currently processed LOD is in, a hierarchical level index of the currently processed LOD; and

querying, according to the hierarchical level index of the currently processed LOD, the quantization parameter offset parameter to determine a quantization parameter offset corresponding to the quantization parameter offset parameter.

18. A decoder, comprising a non-volatile storage medium and a central processing unit, wherein the non-volatile storage medium stores an executable program; the central processing unit is connected to the non-volatile storage medium; and when the central processing unit executes the executable program, the decoder performs a method for point cloud decoding comprising:

performing the following operations for one or more points included in a current coding block;

determining an LOD i where a currently processed point P i is located;

predicting the point P i according to the LOD i to obtain a prediction value of the point P i ;

determining a quantization step Qstep i which is adaptive to the LOD i , comprising:

determining the quantization step Qstep i which is adaptive to the LOD i according to a hierarchical level index and quantization parameter offset parameter corresponding to the current coding block;

determining a quantized residual of the point P i ;

performing inverse quantization on the quantized residual of the point P i according to the quantization step Qstep i to obtain a reconstructed residual of the point P i ; and

determining a reconstructed value of the point P i according to the reconstructed residual of the point P i and the prediction value of the point P i .

19. The decoder of claim 18 , wherein before determining the quantization step Qstep i which is adaptive to the LOD i according to the hierarchical level index and quantization parameter offset parameter corresponding to the current coding block, the decoder further performs:

determining a value of a quantization parameter optimization enable identifier of the current coding block;

if the value of the quantization parameter optimization enable identifier is a first value, determining the hierarchical level index and the quantization parameter offset parameter corresponding to the current coding block; and

determining a quantization step Qstep corresponding to the LOD according to the hierarchical level index and the quantization parameter offset parameter.

20. The decoder of claim 19 , wherein the determining a value of a quantization parameter optimization enable identifier of the current coding block comprises:

parsing a bitstream, and determining the value of the quantization parameter optimization enable identifier in a parameter set of the current coding block.

Assignments (1)

Continuity (2)

References Cited (59)