US 12,462,437 B2
Compression and decompression of sub-primitive presence indications for use in a rendering system
Alper Ozkan, Hertfordshire (GB); and Simon Fenney, St Albans (GB)
Assigned to Imagination Technologies Limited, Kings Langley (GB)
Filed by Imagination Technologies Limited, Kings Langley (GB)
Filed on May 29, 2023, as Appl. No. 18/202,990.
Claims priority of application No. 2207937 (GB), filed on May 30, 2022; and application No. 2207942 (GB), filed on May 30, 2022.
Prior Publication US 2024/0119640 A1, Apr. 11, 2024
Int. Cl. G06T 9/00 (2006.01); G06T 9/40 (2006.01); G06T 15/06 (2011.01)
CPC G06T 9/001 (2013.01) [G06T 9/00 (2013.01); G06T 9/40 (2013.01); G06T 15/06 (2013.01); G06T 2210/21 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of decompressing compressed data to determine one or more sub-primitive presence indications for use in a rendering system, the method comprising:
receiving a block of compressed data for a block of sub-primitive presence indications, wherein the block of sub-primitive presence indications is subdivided into a plurality of parent regions, each of the parent regions being subdivided into a plurality of child regions, wherein the block of compressed data comprises a hierarchical representation of the block of sub-primitive presence indications, wherein: (i) for each of one or more parent regions whose child regions all have the same presence state, parent-level data is included in the hierarchical representation to represent the presence state of the parent region without child-level data for the child regions within the parent region being included in the hierarchical representation, and (ii) for each of one or more parent regions whose child regions do not all have the same presence state, child-level data for the child regions within the parent region is included in the hierarchical representation to represent the presence states for the child regions within the parent region;
determining whether child-level data is included in the hierarchical representation for one of the parent regions;
if it is determined that child-level data is included in the hierarchical representation for said one of the parent regions, using child-level data for said one of the parent regions to determine one or more sub-primitive presence indications in said one of the parent regions; and
if it is determined that child-level data is not included in the hierarchical representation for said one of the parent regions, using parent-level data for said one of the parent regions, without child-level data, to determine one or more sub-primitive presence indications in said one of the parent regions.