GPUOpen-Tools
Compressonator doesn't factor in Alpha when computing MSE
This I would think is a pretty serious issue. I had an issue where my MSE computation doesn't match Compressonator, and it seems that the reason is that Compressonator doesn't factor in Alpha when computing MSE?! This is totally inaccurate of course for many reasons and many textures.
See:
https://github.com/GPUOpen-Tools/Compressonator/blob/b4723bad4025a7561825b91e505d8eeb400f4fa4/Compressonator/Applications/_Plugins/CAnalysis/Analysis/CAnalysis.cpp#L548
https://github.com/GPUOpen-Tools/Compressonator/blob/master/Compressonator/Source/Codec/BC7/Codec_BC7.cpp#L652
Possibly other places too.
@Zelex A issue report has been filed for this and code will be added to the alpha channels.
The use of 3 and or 4 channel calculations in the analysis reports will be correctly displayed in the next release for processed textures.
@Zelex, There is only a partial fix in v4.0 will continue to resolve your issue with additional enhancement to the code