Does anyone know the specifics about how much a backlink from a hyperlink, and a backlink from a hyperlinked image compare? How about if the image has an alt & title tag with keywords?
I don't suppose there is any way of really measuring the difference acurately. However a link from a page is the same if it's text or pictures. Without keywords it's obviously less effective but Google does look at alt text for images so that should compensate for the lack of text on image hyperlinks.