The following is just a test to see if my WordPress installation / Web Server setup / PHP Version / GD Library are actually rendering transparent PNG images correctly (both 8 bit and 24 bit) or if the transparency gets lost.
And the test result is: yes they do render correctly – transparency is preserved:
#1 8-bit PNG
this is a gray box with a transparent 8-bit PNG inside:
#2 24-bit PNG
this is another gray box with a transparent 24-bit PNG inside:
