To load a PNG you need more time. I've tested it. It's not so much. I think bmp was about 30% faster.
In the graphics-memory every graphic, eqal to bmp, jpg, png or CreateImage :D) needs the same memory (=size of bmp). It is only a difference on the disk.
In the graphics-memory every graphic, eqal to bmp, jpg, png or CreateImage :D) needs the same memory (=size of bmp). It is only a difference on the disk.