Google indexes images from PDF files. Fairly limited at present, possibly because the pictures all seem to be drawn from a small set of 500 PDFs stored at
http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/. But I’d guess that, as Google’s machine-learning algorithms get tuned up on this, we may start to see the service expanded to extract and serve images from wild PDFs. I wonder if there will be a Creative Commons filter for images from open access research PDFs? I also wonder if this may enhance the size of the image pool accessible via JURN’s new Image Search feature?
[ Hat-tip: ResearchBuzz ]