The bounding box of the image will always be rectangular; there's no way
Png supports transparent backgrounds (even wonderful 8-bit transparent
backgrounds), but a lot of programs that support the png format do not
support background transparency on pngs.
If you are working on a static web site, your best choice is probably to go
with (yuck) gif.
If you're working on a dynamic web site, you can read the user-agent string to
find out which browser is being used, and return the png if it's capable of
handling transparent backgrounds, or a gif otherwise. (Mozilla has great
support, IE doesn't support it at all).
If you're working on something for print, save it as a tiff. Pretty much any
program that can handle a tiff can handle tiff alpha transparency.
> I want ot create a logo using a picture of an eagle, but I don't want
> the background to show when I use it. In other words I want. the figure
> to be eagle shaped, not rectangular. I already have the xcf version with
> a transparent background. Now, what format should I use to save the
> file? Png seems not to work, I still get the rectangle.
> John Culleton
Gimp-user mailing list