How to use the netpbm utilities

Getting the netpbm package

To create a GIF with a transparent color, you need a few utilities from a fairly recent version of the netpbm package, which is available from,, and (and probably other sites too). If you FTP this, pick a site close to where you are, geographically.

You're welcome to ask me for help in compiling these, but I don't promise to be of much help. I've only recently started to learn the tricks of compiling things on odd platforms.

Here at MIT, Seth Finkelstein compiled this package for AIX, Solaris, and Ultrix, and I compiled it for SunOS:

(note, if you get the binaries for SunOS 4.1.3, you'll be using giftopnm instead of giftoppm; it should work just the same, though.)

How do I make a picture transparent?

The process of creating such an image requires several steps. You could have done all this conversion in one step, also:
giftoppm foobar.gif | ppmtogif -transparent #rgb > fooquux.gif
If you have any questions about this process, please feel free to contact me for help, although I make no claims as to my actual helpfulness. :-)

Please feel free to let me know what you think.

-Eric Mumpower (