Is it possible to crop a profile picture as a circle? I tried PHP crop, but the quality was awful. Color shades changed and image quality suffered. Is there any PHP library which does this properly? Or some Apche program?
You can not crop image to circle. Image must be rectangular. The best solution is to use css with border-radius property - border-radius: 50%. But if you really need a circle you can try to add a frame using ImageMagic. One of possible solutions: http://www.imagemagick.org/Usage/thumbnails/#badge_overlay