I see.
Unfortunately, I don't plan to add compressed texture formats to SFML.
I'm curious why that is.
DDS has made so many strides at the forefront of graphics tech with new improvements in quality.
Now with YCoCg you can have near lossless, but even good old DXT 1 and 3 have are optimized to where you no longer have to fear artifacts.
SFML doesn't support 8bit, but it's also not going to support DDS?
32bit pngs are not very useful for making any kind of an optimized 2D game.