Corrupted photos are best considered lost; quick-formatting might be an option to recover the good ones. In my experience, Recuva is both hit and miss. Specifically with a Canon, you could also try this:
(From the product spec:
CR2 Canon RAW version 2. Photograph from a Canon camera.
CRW Canon RAW. Photograph from a Canon camera.)
I have a Canon 70D camera with a Transcend SDHC 16 GB memory card. At some point, about half of the photos on it became corrupted. I tried downloading the other, good photos to my laptop. They do show up on the computer through one of the USB ports connected to the camera. I tried copying the good photos to a folder on the computer, and while the window that pops up shows movement, no photos are transferred. I used Recuva and was able to pull out old photos from the card, but not the good or the corrupted photos. I'm considering formatting the card then using Recuva again -- if the recovery program could pull up old, deleted photos, maybe it would pull up at least the good photos that I couldn't copy to the computer. Or is there another route I should try? Whaddya think?