> -----Urspr?ngliche Nachricht----- > Von: "Pierre Willenbrock" <pierre at pirsoft.dnsalias.org> > Gesendet: 27.11.07 23:03:13 > An: Ralf Haueisen <ralf.haueisen at web.de> > CC: sane-devel at lists.alioth.debian.org > Betreff: Re: [sane-devel] Canon LIDE 90
> > Ralf Haueisen schrieb: > >> -----Urspr?ngliche Nachricht----- > >> Von: "Pierre Willenbrock" <pierre at pirsoft.dnsalias.org> > >> Gesendet: 27.11.07 22:23:19 > >> An: Ralf Haueisen <ralf.haueisen at web.de> > >> CC: sane-devel at lists.alioth.debian.org > >> Betreff: Re: [sane-devel] Canon LIDE 90 > > > > > >> Ralf Haueisen schrieb: > >>>> Can you send a small image? > >>>> > >>> The image shows the cover of a book... > >>> > >> This looks like the shading correction(corrects for the properties of > >> each ccd cell) is making the image worse. please disable it by changing > >> gl841_init_optical_regs_scan to only disable it: > >> > >> /* if (flags & OPTICAL_FLAG_DISABLE_SHADING)*/ > >> r->value &= ~REG01_DVDSET; > >> /* else > >> r->value |= REG01_DVDSET;*/ > >> > >> The resulting image may give better information. Another possibility is > >> to look at the generated black_white_shading.pnm when > >> SANE_DEBUG_GENESYS=255 is set in the environment. > >> > > > > It is not the shading. > > Well, it does look better. My current guess: either some gpio is > incorrect, or the sensor needs some other clock settings. The noise may > stem from too few light or the data bytes from the frontend are swapped. > > The sensor does not seem to switch the read out pixel, but it does > capture line data, so you end up with the first pixel over and over again. > > First, i'd make sure that i actually get the most significant byte from > the frontend(by trying the possible byte positions in register 0x52) if > you get a noise free image from the scanner, you got the msb right. The > lsb is not that important at the moment(It would be the byte position > where you get a different noisier image). The "correct" msb may be very > dark(not 0 though), you are scanning pixels that are under the scanner > cover). > > Then i'd try to find out which of the clock/gpio registers needs to be > set. An usb log may reveal this. > > Hope this helps, > Pierre > 52=4 53=8 gives a picture with much less noise. setting for the registers 16 to 1d i can not get out of my usb log. I guess there register set the clock for the read out. Maybe someone else has them? But now it close to midnight. cu. Ralf _______________________________________________________________________ Jetzt neu! Sch?tzen Sie Ihren PC mit McAfee und WEB.DE. 3 Monate kostenlos testen. http://www.pc-sicherheit.web.de/startseite/?mc=022220
