Latent-based GPU texture public Prior Art from 2012

Experiments in Luma-Optimized and Mipmapped DXT1 Compression:

https://web.archive.org/web/20140915122940/https://sites.google.com/site/richgel99/luma_chroma_texture_compression

The sample app's archive (with shader source code) is still available here.

Major concepts:

• It splits information by spatial frequency: full-resolution luma/detail plus lower-resolution chroma/color state. The page puts luma in mip 0 and the color/chroma image at half resolution and below.
• It reconstructs the final texel in the pixel shader from separately hardware-filtered components. The page explicitly says bilinear/trilinear/anisotropic filtering works normally because the reconstruction is linear.
• It deliberately makes the encoder aware of the runtime reconstruction. There is even an optional feedback pass that modifies the high-resolution luma to compensate for errors introduced by the compressed, upsampled low-resolution chroma.
• It treats the lower-resolution representation as something that gets interpolated by ordinary texture hardware and then combined with the high-resolution signal—not decompressed into a conventional texture first.
• It even says a preferable version would use DXT5A/BC4 for the high-resolution scalar field instead of abusing DXT1 for luma.