[sane-devel] New Genius CP-SF600 troubles

[Frank Hunleth]

I had been using a Genius CP-SF600 (gt68xx) with sane without any problems.
Actually, it worked very well. Recently I bought a new CP-SF600, and it's
pretty clear that something is different inside of it. On the outside, it
just looks like they changed the USB connector from an regular B to a mini-B
connector. The USB VID/PID is the same on both versions.

My hope was to figure out the difference between this version and the
previous one and submit a patch back. However, I'm running into a lot of
trouble and was wondering if anyone had any pointers. Here's what I know:

The following is a grayscale scan that I made with the Windows driver:

http://dl.dropbox.com/u/37770195/scaninwindows.png

and here's what I get with sane:

http://dl.dropbox.com/u/37770195/sane.png

It seems like a lot of code still works in sane, since I get a recognizable
image. The image looks like it was delta encoded, but that doesn't make
sense to me. I'm not that familiar with scanner technology and I wonder
whether any of you had seen anything like this before.

The other difference that I've seen between sane and the Windows driver is
that sane uses the cism216.fw firmware and the new Windows driver uses
cism603.fw. I tried having sane use cism603.fw, but just received a blank
white scan. I then used a USB sniffer to see what Windows was sending for
the AFE parameters, but it looked like it was just sending zeros. I tried
the same change on the sane side without any luck. Perhaps least encouraging
was that when I used a USB sniffer to see what the raw form of the Windows
scan looked like, it looked similar to the image above. My conclusion from
this was that the cism216.fw firmware might be ok, but that the new scanner
required different post-processing than the old one.

Any pointers would be appreciated since it would be nice to get this scanner
working again.

Thanks,
Frank
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