by Jim
Jul 19, 2006 5:56 PM
I was creating a fancy new icon for a program I'm working on, and noticed that it sometimes wasn't displaying correctly. After a little testing, I determined that in certain situations, Windows XP does not correctly render partially transparent pixels in a 16x16 icon.
Sometimes pixels with anything less than full opacity are rendered as transparent. Depending on the icon and how it is drawn, this may be hardly noticable. But here is my test icon:
First is the Explorer thumbnail view, second is what the icon looks like in the list or details view - that's the correct rendering.
The icon is correctly upsized to 32x32 for the icon view in explorer, and native 32x32 icons don't appear to have any problems.
Lesson - minimize use of partial transparency in 16x16 icon formats.