There is an open source application that appears to compete with GIMP 
plus plugins for handling digital camera images.  The package is called 
darktable,

URL:

http://www.darktable.org/about/

The claim is that it will install under SL6, preferably X86-64
RHEL 6 / SL 6 / Centos 6, using the following sequence:

         install the linuxtech.repo config file if you don't have it 
already:

su - root
cd /etc/yum.repos.d/
wget http://pkgrepo.linuxtech.net/el6/release/linuxtech.repo

         install darktable:

yum --enablerepo=linuxtech-testing install darktable

Does anyone have experience with either this application or the 
linuxtech repository?  Does anyone know if this is a "safe" repository 
to use?  Had EL proper polymorphism and encapsulation, this sort of 
issue would not arise; however, under the present design, if a 
repository (e.g., linuxtech) overwrites a systems library, etc., the 
results can be less than desirable.

Yasha Karant