Olano, Marc, Dan Baker, Wesley Griffin, and Joshua Barczak. 2011.
Variable Bit Rate GPU Texture Compression.
Computer Graphics Forum 30 (4): 1299-1308.
Variable bit rate compression can achieve better quality and compression
rates than fixed bit rate methods. None the less, GPU texturing uses
lossy fixed bit rate methods like DXT to allow random access and
on-the-fly decompression during rendering. Changes in games and GPUs
since DXT was developed make its compression artifacts less acceptable,
and texture bandwidth less of an issue, but texture size is a serious
and growing problem. Games use a large total volume of texture data, but
have a much smaller active set. We present a new paradigm that separates
GPU decompression from rendering. Rendering is from uncompressed data,
avoiding the need for random access decompression. We demonstrate this
paradigm with a new variable bit rate lossy texture compression
algorithm that is well suited to the GPU, including a new GPU-friendly
formulation of range decoding, and a new texture compression scheme
averaging 12.4:1 lossy compression ratio on 471 real game textures with
a quality level similar to traditional DXT compression. The total game
texture set are stored in the GPU in compressed form, and decompressed
for use in a fraction of a second per scene.