Scaling of quantization parameter values in geometry-based point cloud compression (G-PCC)

1. An apparatus configured to decode a point cloud, the apparatus comprising:

a memory configured to store encoded point cloud data; and

one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to:

receive the encoded point cloud data;

determine a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

decode the encoded point cloud data using the final QP value to create a decoded point cloud.

2. The apparatus of claim 1 , wherein the one or more processors are further configured to:

decode a node QP offset syntax element to determine the node QP offset; and

decode a geometry QP multiplier syntax element to determine the geometry QP multiplier.

3. The apparatus of claim 1 , wherein to determine the final QP value, the one or more processors are further configured to determine the final QP value according to an equation: qpFinal=((base_qp+slice_qp)<<geom_qp_multiplier_log 2)+(node_qp_offset<<geom_qp_multiplier_log 2), wherein qpFinal is the final QP value, base_qp is a base QP value, slice_qp is a slice QP value, node_qp_offset is the node QP offset, and geom_qp_multiplier_log 2 is the geometry QP multiplier.

4. The apparatus of claim 3 , wherein the node QP offset is a multiple of (1<<geom_qp_multiplier_log 2).

5. The apparatus of claim 3 , wherein the one or more processors are further configured to round the final QP value to (1<<geom_qp_multiplier_log 2).

6. The apparatus of claim 1 , further comprising a display configured to display the decoded point cloud.

7. An apparatus configured to encode a point cloud, the apparatus comprising:

a memory configured to store point cloud data; and

one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to:

receive the point cloud data;

determine a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

encode the point cloud data using the final QP value to create an encoded point cloud.

8. The apparatus of claim 7 , wherein the one or more processors are further configured to:

encode a node QP offset syntax element that indicates the node QP offset; and

encode a geometry QP multiplier syntax element that indicates the geometry QP multiplier.

9. The apparatus of claim 7 , wherein to determine the final QP value, the one or more processors are further configured to determine the final QP value according to an equation: qpFinal=((base_qp+slice_qp)<<geom_qp_multiplier_log 2)+(node_qp_offset<<geom_qp_multiplier_log 2), wherein qpFinal is the final QP value, base_qp is a base QP value, slice_qp is a slice QP value, node_qp_offset is the node QP offset, and geom_qp_multiplier_log 2 is the geometry QP multiplier.

10. The apparatus of claim 9 , wherein the node QP offset is a multiple of (1<<geom_qp_multiplier_log 2).

11. The apparatus of claim 9 , wherein the one or more processors are further configured to round the final QP value to (1<<geom_qp_multiplier_log 2).

12. The apparatus of claim 7 , further comprising a sensor configured to generate the point cloud data.

13. A method of decoding a point cloud, the method comprising:

receiving encoded point cloud data;

determining a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

decoding the encoded point cloud data using the final QP value to create a decoded point cloud.

14. The method of claim 13 , further comprising:

decoding a node QP offset syntax element to determine the node QP offset; and

decoding a geometry QP multiplier syntax element to determine the geometry QP multiplier.

15. The method of claim 13 , wherein determining the final QP value comprises determining the final QP value according to an equation: qpFinal=((base_qp+slice_qp)<<geom_qp_multiplier_log 2)+(node_qp_offset<<geom_qp_multiplier_log 2), wherein qpFinal is the final QP value, base_qp is a base QP value, slice_qp is a slice QP value, node_qp_offset is the node QP offset, and geom_qp_multiplier_log 2 is the geometry QP multiplier.

16. The method of claim 15 , wherein the node QP offset is a multiple of (1<<geom_qp_multiplier_log 2).

17. The method of claim 15 , further comprising rounding the final QP value to (1<<geom_qp_multiplier_log 2).

18. The method of claim 13 , further comprising displaying the decoded point cloud.

19. A method of encoding a point cloud, the method comprising:

receiving point cloud data;

determining a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

encoding the point cloud data using the final QP value to create an encoded point cloud.

20. The method of claim 19 , further comprising:

encoding a node QP offset syntax element that indicates the node QP offset; and

encoding a geometry QP multiplier syntax element that indicates the geometry QP multiplier.

21. The method of claim 19 , wherein determining the final QP value comprises determining the final QP value according to an equation: qpFinal=((base_qp+slice_qp)<<geom_qp_multiplier_log 2)+(node_qp_offset<<geom_qp_multiplier_log 2), wherein qpFinal is the final QP value, base_qp is a base QP value, slice_qp is a slice QP value, node_qp_offset is the node QP offset, and geom_qp_multiplier_log 2 is the geometry QP multiplier.

22. The method of claim 21 , wherein the node QP offset is a multiple of (1<<geom_qp_multiplier_log 2).

23. The method of claim 21 , further comprising rounding the final QP value to (1<<geom_qp_multiplier_log 2).

24. The method of claim 19 , further comprising generating the point cloud data.

25. A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to encode a point cloud to:

receive point cloud data;

determine a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

encode the point cloud data using the final QP value to create an encoded point cloud.

26. An apparatus configured to encode a point cloud, the apparatus comprising:

means for receiving point cloud data;

means for determining a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

means for encoding the point cloud data using the final QP value to create an encoded point cloud.

27. A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to decode a point cloud to:

receive encoded point cloud data;

determine a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

decode the encoded point cloud data using the final QP value to create a decoded point cloud.

28. An apparatus configured to decode a point cloud, the apparatus comprising:

means for receiving encoded point cloud data;

means for determining a final quantization parameter (QP) value for the point cloud data as a function of a node QP offset multiplied by a geometry QP multiplier; and

means for decoding the encoded point cloud data using the final QP value to create a decoded point cloud.