If the jpg image doesn't have exif header you need to create it first:
jhead -mkexif
Then enter the time stamp data:
jhead -ts2009:08:15-10:30:00
I wanted to have a quick way to rotate the images I take with my digital camera. The Olympus Camedia C-4000 always writes "1" als orientation into the EXIF data (either it doesn't have an orientaiton sensor or it is broken), therefore I cannot rotate the images automatically by the command
jhead -autorot *.jpg
So I created a desktop file ~/bin/rotate90clockwise.desktpop with the following content
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.