[sane-devel] [CanoScan5000f] Analyse of logs

[m. allan noah]

> > Ok but :
> > - There are more thant 3 blocks which seems to be image data: 2 for 
> > calibration and 1 for the picture ?
> > What is the format of the sent picture ? RAW ? it might be possible to 
> > find this no? To be able to determine what size if may have.
> > For exemple : 100dpi, 1cm2 is about 39x39 pixels : this represents 1511 
> > pixels. 8bits per pixel ? 16 ? (don't know..) if  8 : 4968 hex codes, 
> > true ?
> > 
> The scanner may scan more than asked for, and the front end will use 
> what it needs. 39x39 may scan as 40x40 or 64x64 or ..... It is also 
> possible that 100dpi scans as 150dpi. OK not that likely but be prepared 
> for it.

it is also possible that the scanner scans full-width of page, even when 
you ask for less. the way to tell is to take two dumps at two different 
widths, but leave all else the same.

> A colour scan is normally 24bits - 3 bytes per pixel. But again other 
> values are possible.

i would recommend comparing logs of a color scan and a black and white. i 
have seen really cheap scanner do all scans in jpeg color, and the lineart 
mode was simulated in the driver.

allan

> > 
> > - There is apparently a timeout when sniffing a big scan or a preview : 
> > my computer my be to slow :( (Athlon 600Mhz, 256RAM). The scan stops at 
> > that point :(
> > 
> > Now I have to understand libusb in order to try and get an answer of the 
> > scanner from Linux...
> > 
> > Thanks,
> > Thibault
> > 
> > 
> 
> 
> 

-- 
"so don't tell us it can't be done, putting down what you don't know.
money isn't our god, integrity will free our souls" - Max Cavalera