High-quality texture compression using adaptive color grouping and selection algorithm

Texture compression is an important technique to reduce memory storage and increase rendering speed in graphic processing units (GPUs). To ensure fast decoding and retain random memory access characteristics, the industry standard DXTC compression finds an approximate line segment in color space for each 4×4 block. The idea has been extended to multiline solutions by segmenting the 4×4 block into several partitions and adopted by the new format BPTC. BPTC can provide the highest quality than other texture compression standards. However, the limited partition combinations used in BPTC would smooth the texture detail in some cases. This work introduces an adaptive color grouping and selection algorithm to relax the texture smoothing issue. Simulation results show that the proposed algorithm can improve the average PSNR by 0.78 dB for those blocks.