Hi Fred, Don't give up yet, some suggestions you probably already heard below...
--- Fred Odendaal <[email protected]> wrote: > So, I'm thinking "I've got a degree in comp. sci. How difficult can it > be to write a scanner driver?" ...big snip... > Finally after many Windows scans and log files at various different > sizes, resolutions, and colour or gray scale mode I start writing the > backend. It only took me about 2 weeks before I could scan on Linux, but > this is the easy part! What I soon discovered is something called > CALIBRATION. At 600x1200dpi colour resolution the Windows driver > actually does ~20 scans off to the side of the glass flat bed. I have no > idea what its doing. By looking at the usb logs it appears to be setting > the gain and the dc offset in a gradual fashion over several calibration > scans. Dump the received binary data to an image and then just see which control register they're iterating over. Then it's just a matter of figuring what they want the end image to look like (ie. adjust offset down until black pixels are < XXX, then increase gains until white pixels are near YYY). The received calibration image was really helpful when I was trying to figure out what the heck the Microtek driver was doing! It may also be adjusting the individual pixel gains for each sensor element. If there's a really large download of slowly varying #s between scans that might be a pointer. Good luck, __________________________________ Do you Yahoo!? Make Yahoo! your home page http://www.yahoo.com/r/hs
