Guillaume Gastebois schrieb: > Hello, > > Selon Pierre Willenbrock <pierre at pirsoft.dnsalias.org>: > >> Hi, >> >> Guillaume Gastebois schrieb: >>> Hello, >>> >>> So, what's the next step ? Re-enabling shading ? >> Yes, but only after the shading-calibration is able to get black level >> information.(This really needs a better api..) > > How to do that ? Do you mean a better api adapted to lide 90 or for all > genesys > backend ? Do you have some code ?
It is not as bad as i initially thought, the functions for receiving black/white level information for shading are already available. But there is some code duplication between genesys.c and genesys_gl841.c/genesys_gl646.c. All three need to gather black/white level information, for the various calibrations. >>> Do you think that last modification "for (i = 150; i..." is necessary ? >> Yes. Some time back, that part of the code just used the middle half of >> the scan, exactly to drop the dummy black pixels at the begin. That >> didn't work too well, missing some low black levels. >> >>> Is it time to fine tune registers 52... ? >> Try increasing register 53, 55, 57 by one. Attached is a small program, >> that shows the probability of any two-byte pair appearing in a file. It >> takes the file as input and dumps an portable anymap(pnm) as output. >> I created that program for something completely unrelated, but it proved >> useful. >> >> I used it on offset1_1.pnm(as offset1_0.pnm is only black). >> The image should show a fuzzy vertical and horizontal bar, near >> top/left. Currently, the horizontal bar is more a line, the vertical bar >> is correct(it shows the relationship between the low byte of one pixel >> and the high byte of the _next_ pixel). >> > OK, interesting program. I'll try it tonight. > > One more thing, what are you thinking about output image quality ? Is that > normal with todays calibration or is it another problem ? Well, i, for one, can see the impurities of the white inside of the scanner lid. There are only very faint vertical lines, if at all. Example attached. > Regards > Guillaume > >>> Regards >>> Guillaume >> Regards, >> Pierre >> >>> Pierre Willenbrock a ?crit : >>>> Guillaume Gastebois schrieb: >>>>> Hello, >>>>> >>>>> Yep, I write "for (j = 150; j...." instead of "for (i = 150; i....." >>>>> Now second set seems good. Result is on : >>>>> http://ggastebois.free.fr/lide90_snoop/20_test1.tar >>>>> >>>> Hi, >>>> >>>> i am sorry, i actually wanted 450, but didn't realize until just now. I >>>> missed that the calibration dump images are really grayscale images, >>>> although stored in color pnms. 1 pixel in image is 3 pixels for the >>>> calibration... >>>> >>>> I hope this fixes that part of the calibration. >>>> >>>> Regards, >>>> Pierre >>>> >>>>> Regards >>>>> Guillaume >>>>> >> > > > -------------- next part -------------- A non-text attachment was scrubbed... Name: canon-lide-35-example.jpg Type: image/jpeg Size: 6061 bytes Desc: not available Url : http://lists.alioth.debian.org/pipermail/sane-devel/attachments/20080221/bebc286c/attachment.jpg
