Are you sure you did not make a typo? You write netbpm (as in beats per minute) here but as far as I know the product is called netpbm.
Just did a quick test... installed NetPBM form the base repository, the library is installed in the /usr/lib folder.
Configuring Gallery2 to use the /usr/lib folder gives the following result after executing the Test Settings:
NetPBM binary test results
Binary Name Pass/Fail
pnmscale Failed
pnmcut Failed
pnmfile Failed
pnmcomp Failed
pnmflip Passed
I think we need to install an older version of NetPBM or try to convince the maintainers of the gallery2 to incorporate the changes reflected here:
http://netpbm.sourceforge.net/doc/pnmscale.html (obsolete since version 10.20 (January 2004) and replaced by pamscale)
http://netpbm.sourceforge.net/doc/pnmcut.html (obsolete since version 9.20 (May 2001) and replaced by pamcut)
http://netpbm.sourceforge.net/doc/pnmfile.html (obsolete since version 10.9 (September 2002) and replaced by pamfile)
http://netpbm.sourceforge.net/doc/pnmcomp.html (obsolete since version 10.21 (March 2004) and replaced by pamcomp)
I don't use NetPBM but use Imagick and GD (the latter is incorporated in PHP in SME7.0). The first can be downloaded and installed here:
http://www.imagemagick.org/script/binary-releases.php, I succesfully use version 6.2.6-4. The lastest official acknowledged version for SME (6.0.7.1-14) can be obtained from the base repository using the following line:
yum install Imagemagick