Hi Johann, great to her from you! First of all the whole backend is based on code I got from Plustek, therefore it's sometimes not really clear what they've done. Esp. the differences between the originally supported devices are "hardcoded" by using CCD-type, PCD-id and motor type...
Anyway. Calibration is a problem for me so far, as this does not really work for correctly for my 670 here. We might have to write new routines for the CIS devices.=20 Before you continue, I suggest to use at least the 0.45-TEST2 version from www.g-jaeger.de/scanner/plustek.html. This one provides a better picture quality on the CanoScan devices even without calibration... Your questions: On Sonntag, 17. November 2002 16:58, Johann Philipp wrote: > Hi > > I'm happy to post a definitely positive message: My CanoScan N1240U is > working with the plustek backend. Some details: > Scanner is a LM9833 based CIS type with 1200x2400dpi @ 48bit color dept= h, > Sane is version 1.0.9 taken from cvs yesterday, > adaptions were made only to plustek-devs.c and plustek.conf. > Great work, Gerhard! I have been working on a CanoScan backend within t= he > canonscanner project on sourceforge.net and were able to scan with it t= oo. > But your version is much more flexible and stable. > I need to test some more on all the hardware settings, before I will > provide you with a "non-dangerous" patch for the N1240U. Also I hope to= get > the calibration working, but there are a few questions open: > > 1) Basically the routines seem to work, but I need some more control on= the > Y-positions / sizes of the white and black part of the calibration stri= p. > As far as I have seen, I cannot control this completely in plustek.conf= =2E > Can you give some help, where and for what to start looking? The X/Y positions of the strip can be set in plustek-devs.c at the DCapsD= ef entry, the size is currently fixed inside the calibration routines to the width of the scanbed - see the four main calibration routines: coarse calibration: usb_AdjustGain() usb_AdjustOffset() fine calibration: usb_AdjustDarkShading() usb_AdjustWhiteShading() At least the fine calibration is not yet activated as I have too much trouble with it (disabled by the flag WAF_SKIP_FINE in DCapsDef entry of the device... For debugging the output of the calibration data, you might set the debug-level of the backend to 20 and you'll get a bunch of *.raw files... > 2) What for do you need the "black optical pixels" (regs 0x1c and 0x1d) > during calibration? Sniffed data says that my windows driver software n= ever > uses these during calibration. Hmpf - good question! I thought I got those settings from the various test-programs around, but nope! Well in fact I guess those are settings from another scanner so far. They're used in function usb_AdjustOffset() but aren't of much use so far... I'd be happy if you can manage to provide some kind of calibration code for this scanner type... > > Greetings > Johann Cheers Gerhard BTW: I assume, that you're talking german and we might continue in a private discussion...
