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The Netpbm PAM documentation suggests that I will have a fairly seamless transition if I choose to start using PAM instead of PPM/PGM/PBM as an image format:

"PAM" is in fact a fourth format. But it is so general that you can represent the same information in a PAM image as you can in a PBM, PGM, or PPM image. And in fact a program that is designed to read PBM, PGM, or PPM and does so with a recent version of the Netpbm library, will read an equivalent PAM image just fine and the program will never know the difference.

[Updated: 09 October 2005 ]

Note: The above comment is also included in man pam on the systems that I am having trouble with.

However, when I run Netpbm utilities on Ubuntu (several versions including 12.10), it does not work as advertised:

$ pnminvert
pnminvert: bad magic number - not a ppm, pgm, or pbm file

I have verified that some other distributions, as well as from-source builds of netpbm-super-stable (also stable, advanced), do not have this problem.

It looks like from the packages page, that this package is being updated periodically, so I can't figure out why the Ubuntu versions wouldn't work.

I want to deploy tools based on this to an arbitrarily large number of machines, so build-from-source isn't appealing. Any ideas about how to make this work on Ubuntu?

share|improve this question
I have found that ImageMagick (e.g. convert,display) knows how to deal with simple PAM images. You can generate a PAM image with convert - pam:- <input_file >output_file –  nobar Feb 19 '13 at 22:54
Maybe build-from source isn't such a bad idea -- just make it part of your deployment. –  nobar Jun 22 '13 at 17:22

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