RDF, image metadata, jpg/jpeg image annotation (RDFPic)

I am constantly adding images to my genealogy database. The final destination of these images is the web. The annotation of these images is stored inside the image file itself. I use jpeg images and I annotate the images with RDFPic. RDFPic is a java application that stores metadate using the RDF (resource description framework) format in the comment section of the jpeg file. Unfortunately the program can handle only jpeg images and not tif or png images.