MMBase uses ImageMagick's convert tool to build and convert its images.
ImageMagick is already part of the Red Hat distribution. Check its availability using:
rpm -q ImageMagick  | 
If ImageMagick is not available on your system, install it using up2date:
up2date  | 
or download it from the Red Hat Network:
https://rhn.redhat.com/  | 
and install it by hand:
rpm -ihv ImageMagick-xxx.rpm  |