My site has been submitted to and verified with Google webmaster tools for a long while now, but when I look at how many of my images have been both submitted and indexed, it is only a fraction. Nearly 750 images exist, but only 163 have been submitted.

Is there something I can do about this? I can't find a related topic in the forums, but a pointer to a thread or personal experience with this issue would be greatly appreciated !:)!