hi.about netpbm.help!

[EricYang]

i have installed netpbm in my computer (redhat 7.0) and the path is
  /usr/local/netpbm/
  but it always told me i set the wrong path and i  can't get the contractible image automatic when someone upload his/her image.Who can tell me the current netpbm path.There are so many command in netpbm folder but i don't  know which command  can produce the contractible image automatic.
  /usr/local/netpbm/bin can't work either.
  any idea?
  thanks