SANE, or Scanner Access Now Easy is a free, open source driver that works on most existing models of scanner for the backed, and speaks to any number of front end softwares for scanning, GUI-based or otherwise. The thing is, there are a few dozen different drivers in this package, and each speaks to a wide variety of scanners - and so the quality of imaging, the access to options, the support for the driver, all vary greatly. Although each driver works with many different scanners, even the results here vary, depending on their color profiles, lights, buttons, etc.
With the four scanners I had available in my studio, each got very different qualities of image than the commercial scanner driver they came with and used in PhotoShop (always of lower quality in terms of color matching). Here is a list of supported devices by manufacturer or backend - and note that each backend is in a different stage of development.
Sadly, my high-end CanoScan 9900F is not supported. That's OK; I prefer HP scanners anyhow.
My ScanJet 3400c is only a USB 1.0 scanner, relatively slow and lo-res, so not ideal. It is no longer supported on the Mac, so in fact needs SANE there as well as Linux. It uses the sane-niash backend, but despite having "complete" support within the documentation, it is limited in function and the color matching was pretty awful beyond a foot in space. This was the first scanner I used in the series back in 2005, and I actually hand colored all my images in PhotoShop - VERY time consuming.
The HP G3110 uses the sane-hp3900 driver with only "basic" support. Again, the bigger issue is color. Below, compare the same scanner with the top open and a scan of the studio environment between the Linux driver and the PhotoShop / HP driver on the Mac.
Very different quality of image. Although I did some touching up to tease out the image after what is pictured above, it still had some issues. The sane-hp3900 is considered an "alpha" driver.
Finally - LUCKILY! - I worked with the G4050 and the sane-genesys driver. This is actually my favorite scanner all around, in terms of quality imaging and focal length and point (Giverny of the Midwest was scanned with this scanner), so I'm quite pleased it tested best. Although this scanner only has "good" support, I was able to get a fairly decent image and color at 300 DPI. It's distinct from the PhotoShop image, but work-able. See below a scan of a 2 inch deep tupperware against my window frame and a blue sky - the first is the RasPi scan, the second on my laptop...
Score!
I am able to control resolution and bit depth via command line, with "scanimage", and I just save to the card. I had to install some drivers on my Mac to view the files, though one could email or else network the Pi in order to grab the images as well. Next up I want to auto-detect the scanner on startup, have a pushbutton and perhaps visual feedback (LED? LED Screen?) to initiate and track the scan. I've got the Pi working off batteries, and am testing the scanner with batteries this week as well.
More soon.
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