- if ((io->flags & IMAGE_ALPHA) || (io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
- png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
+ if (!(io->flags & IMAGE_ALPHA))
+ {
+ if (io->flags & IMAGE_IO_USE_BACKGROUND)
+ {
+ png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
+ read_flags = (read_flags | IMAGE_ALPHA) & IMAGE_CHANNELS_FORMAT;
+ }
+ else if ((io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
+ png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
+ else
+ png_set_strip_alpha(rd->png_ptr);
+ }