Need input for creating new icon

[Richard Shaw]

I'm working on packaging the spacenav group of programs one of which
is a gui app to setup the configuration of the spacenav daemon. It
currently doesn't provide an icon so I thought I'd try my hand at it.

Which resolutions do I really need to provide?

Since I'm a CAD guy I used Unigraphics to model and export a high
resolution image. Unfortunately the only export option was tiff. I
then opened it in GIMP and set the background as transparent and saved
it as a PNG.

Of course with this method SVG is not an option....

Any advice would be appreciated.

Thanks,
Richard