Hadoop-thumbnail is a project mainly written in JAVA and C, it's free.
This project is a demo of creating thumbnail images via MapReduce in a map only job using ImageMagick via JNI.
Prereqs: Java ImageMagick (& ImageMagick-devel on RH) gcc maven3
Tested on: CentOS release 5.6 Mac OS X 10.8.0 (very lightly tested)
Try it on a machine with the `hadoop' command configured: $ ./run-thumbnail-mapreduce.sh