[sane-devel] [CanoScan5000f] Analyse of logs

[David Stevenson]

Thibault North wrote:
> 
>> Unlikely, all things are possible but the windows driver will be 
>> reasonably efficient, and will not send the image more than it needs to.
>>
>> For a small image the calibration data may be larger than the image. 
>> You could try a larger scan - expect a very large log - and look for 
>> where the data is similar and where there is a large amount of new data.
>>
>> David
>>
> 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.
A colour scan is normally 24bits - 3 bytes per pixel. But again other 
values are possible.
> 
> - 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
> 
>