Image Capture and CanoScan 8800F I have discovered, through personal experience and checking online forums, that the software for my 10-year old, CanoScan 8800f, film and negative scanner is no longer supported for High Sierra users.  Users of this particular scanner, a wonderful workhorse, are furious.  I know that one solution is to purchase VueScan software for about $50.  I have seen that another solution would be to find an open-source driver.
As I continued my search for an answer, someone noted that scanners should work with Image Capture, but Image Capture does not recognize this scanner.  Further searching revealed (and I hope I have this right) that Image Capture does not "see" this scanner because the scanner is not TWAIN-compliant. Is there some way I can make this scanner TWAIN-compliant?
I have been using VueScan with my Epson slide scanner, with better results than the rather ropey SW that came with it.
50 bucks isn’t much, and you can try it first for free to at least see if it will work with your scanner at all.
Otherwise, I can only wish you luck (I’m no HW or SW expert…).