you have to use photoshop to add the text onto the icon itself. use a free software called paint.net
open the picture file in paint.net
add layer, then select a gray box to put at the bottom of the picture file. put the transparency at 50% (or whatever you feel looks nicer, i use 55% for myself)
add another layer, then select text box and put this on top of the previous layer.
wala you now have a nice picture icon with text to use for desktop visualizer.
you can refer to my post to see how the effect looks like:
http://forums.hardwarezone.com.sg/70609982-post1432.html