Jpegrdf reads and manipulates RDF metadata stored in the comment section of JPEG images. It can extract, query, and augment the data. Manipulating JPEG images with jpegrdf does not modify the actual image data or any other sections of the file.
This program was inspired by the Rdfpic application. I couldn't (well, I wouldn't, anyway) have written it without the Jena repository. It currently relies on Jena 1.6. I plan to upgrade to Jena 2 soon.