Scanner Compatibility

Predrag Punosevac punosevac at
Sat Dec 8 12:14:13 PST 2007

Michaël Grünewald wrote:
> Predrag Punosevac <punosevac at> writes:
>> Let me clarify firstly some things.
> Thank you very much for this very detailed answer, it's very nice
> from you!
>   [SNIP]
>> In essence your scanner uses this file to explain the Sane the page
>> layout and graphics. So it is not a driver!
> If I do understand, this seems a close analogue of PPL files in the
> printing world, right?
> [SNAP]

You meant PPD files? (Of course there is subtitle difference between 
CUPS-PPD files and generic PPD files used by LPD).
My hunch is yes but I have not read enough documentation to say yes or 
no. I would really like to hear from some Sane developers or
IT professional who works on scanners who will give us more explanation.
So far my understanding is following. The kernel recognizes your 
scanning device using the  uscanner0 driver and usb daemon as it is 
attached to USB.
Sane-backhands and Sane-fronthands is a collection of drivers that speak 
scanner language. As a mater of fact it used to be that you need one 
driver per application  per scanner (like printing in old times) but I 
think that one of chef achievements of Sane project is to automatize 
writing drivers so that you need to write one driver per application and 
then hack it to work on all supported scanners.  Firmware is dictionary 
which teach sane backhand to speak proprietary language of a particular 
scanner. So it is  something like this
scanner<---> uscanner0<---->sane-backhands<----> Xsane
>> I see no reason why should sane-backhands work any different on
>> amd64.
> Now you made clear that these binary blobs consist of data (and not
> of a cpu program), I do not see either. I will soon be able to tell :)
Does the generic kernel on for amd64 contains the same drivers as for 
i386? Also kernel driver like uscanner and  even  usb daemon  might
be on the different level of the development than in i386 as they really 
need to interact to  different amd64 kernel.
A kernel developer could easily clarify this for us.

>> On another hand if you are using amd64 that tells me that you
>> are running serious production servers so why would you want to attach
>> a scanner to  such  machine is not really clear to me.
> In fact, I have no serious reason to run amd64 since I use my amd64
> computer as a ``user workstation'' and the main benefit from running
> amd64 is to manage huge amounts of RAM --- as far as I can tell from
> the various docs I have read. My reasons to run amd64 are mainly geeky
> or childish :)
I hope you do not have 32 Gb of RAM as my neighbor who is a gamer  and 
passionately in love with
Windows Vista:-) On another hand those gamers are the reason that I can 
go to junk yard and get a
PIII with 512 Mb of RAM and 10Gb Hard-drive for $5. I am a happy camper!

>> As I said before the handbook is excellent but here is my quick and
>> dirty step by step how to for scanners.
> [SNIP]
> Thanks a lot for this con tribution,
I realized that Handbook article about scanner could be appended but 
there are people on this mailing lists who are qualified to do so
unlike me.


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