Do I need to install the netpbm-progs.i386 and netpbm-devel.i386 also??
netpbm is the libraries - needed by everything (compiled programs, etc) netpbm-progs is the command line utilities netpbm-devel are the header files, etc needed to compile programs using the netpbm libraries.
Depending on whether you are using C/C++ programs (need the -devel to compile) or bash scripts (use the commandline utils, thus need -progs) you'll want to have one or the other (or both...)
Cheers, MaZe.