Vampyre Imaging Library is up to date and actual. Supports Free Pascal and Delphi, I personally have successfully built and used it @ Raspberry Pi 2

It's just its home page that smells so, stuck in 2009 with a grossly outdated download link (ptruint = cardilnal, the horror).

For up to date, see the author's forum:
You can ask him question and he will answer

The library is priceless in its huge scope of supported formats, both image file formats and pixel formats, and its built-in Lanczos resampler.
Must have if you work with GLES2 which requires you convert image into required internal format yourself.

The source code is MPL1 + LGPL, will be migrated to MPL2 (which has built-in clause about double-licensing under GPL) - which is *priceles* since I'm moving onto grayer stuff of modding where I can't take unmodded LGPL with me.