Hello, I am currently working on a SANE backend for rts8891 based scanner such as the HP Scanjet 4470c and UMAX Astra 4400/4450. I have set up a page at http://stef.dev.free.fr where you can get the current work in progress.
What is working: - origin detection, gain, offset and shading calibration - 75, 150, 300 and 600 dpi color modes are working fine - 1200 dpi almost work, the data needs to be realigned for some "saw-tooth" effect Things to fix: - warming up, currently the first scan gives "overlighted" colors Features to add: - gray level scans - button reading The transparency adapter isn't supported at all since I don't have one to test. During tests I wiped out the data in the NVRAM, and now the USB id of the scanner has gone from 0x03f0/0x0805 (HP4470c) to 0x1606/0x0070 (UMAX Astra 4400). I disabled those dangerous acesses to NVRAM, and such thing won't happen again. However, this confuses the windows driver, and I'm not able to generate logs for the gray level scans. I installed the driver for the UMAX 4400 which detected the scanner but crashed everytime I tried to scan. So I'd be glad if someone could record USB activity for gray preview and 150, 300, 600 and 1200 dpi gray scans and send me these logs. I expect to have it finished and hopefully ready for inclusion in regular SANE CVS by december. While this backend is written from scratch, some clues of the working of the scanner were gathered from the hp44x0backend (by Johannes Hub) and the hp3500 (by Troy Rollo). Regards, Stef