This simple program generates thumbnails of digital camera raw image files 
using libopenraw and GDK. It supports the same file formats as libopenraw 
<http://libopenraw.freedesktop.org/wiki/FileFormats>.

This thumbnailer is designed to be small, lightweight, and fast. It is 
primarily intended to be used with file managers (although it could easily 
be used by a photograph management program) and is used by thunar-thumbnailers.

  Usage: raw-thumbnailer -i input_file -o output_file -s size 

raw-thumbnailer requires libopenraw (also available at SlackBuilds.org).