Scanjet 4670?

[ffutures]

One possibility I'm looking at for book scanning is HP's old Scanjet 4670, which seems to have been VERY strange but would possibly do quite a lot of what I would want. Basically, it's a transparent inverted flatbed, basically a thick lid containing the scanning mechanism - you put things under the lid face up, you can see the alignment precisely because the scanner is transparent, glass front and back. Doesn't solve all of the problems of scanning old books etc. but it looks like it would generally get the alignment right first time, and re-positioning stuff repeatedly to fix alignment problems is one of the things that buggers books.

They don't seem to have a stellar reputation for colour fidelity, but since 99% of what I scan is grey scale or text that wouldn't necessarily be a huge problem.

http://reviews.cnet.com/scanners/hp-scanjet-4670/4505-3136_7-30535469.html

http://www.lordpercy.com/hp_scanjet_4670_scanner.htm

The trouble is I've never used one, or seen one outside a photo, and can't currently find anyone with one for sale. Looks to have been USB, not USB 2, which may mean slowish speed. Anyone know anything about them? Was there a later version?

Comments

[ffutures.livejournal.com]

Getting things flat and really well focused is the big problem - you have to use a piece of glass or something, which leads to problems with reflections. nojay is working on something like this.

[the-magician.livejournal.com]

Flat can be fixed in software, which is what I believe Google uses.

E.g. Wisebook
WiseBook automatically eliminates skewed images and removes unwanted fan and gutter. [...] When used with wide-format flatbed or planetary scanners, Wisebook scans two pages at once automatically splitting pages and correcting for book-fold. The same process can be applied to already scanned images.[...] The book-fold area is normally darker with the gradient incline. WiseBook can automatically correct brightness of the fold removing the gradient. This procedure can be done in the post-processing of the image after separating the pages. WiseBook allows for manual correction of the preview cutting area.

and
Google is rumored to use a pair of 45 degree optical systems. These project an infrared grid onto the pages and then use that sensed grid to provide for image deskewing and distortion correction.
article on book flattening algorithms

"Focussed" can be most easily handled by using a lot of light and a small aperture for great depth of field! And good quality lenses of course (which aren't cheap). Though a small aperture may mean your lens only really needs to be very sharp in the central regions and you don't have to worry so much about the edges.

In any case, more time/money than I'm sure you're willing to throw at it!

I'd never heard of this transparent scanner before, but it sounds really interesting and I hope that you manage to find one at a good price and get it working well for you.