[sane-devel] Epson 3490

[Bjorn Solberg]

Oliver Schwartz writes:

> Hi,
>> I don't have access to that information right now, so I'll check
>> that tonight also.  It is whatever firmware came with the scanner -
>> esfw52.bin.

> yes, but at least for other epson scanners these firmware files are 
> available in different versions. The filename is always the same.

$ strings esfw52.bin  | tail
Thu Apr 14 2005 14:32
1.08 u
A0~      
 4{ 
r {o0r
~rSP
u89u9
u89u9
EPSON   GT-F520         1.08
qThu Apr 14 2005 14:32


> Another thing that I'm interested in is whether only the size of the 
> scan area is wrong or if the origins of the scan area are also not 
> set correctly (i.e. options -l and -t in scanimage)

-x and -y are reduced by about 25% - i.e. I ask for 100mm and get only
75mm.

-l and -t are ditto reduced by about 25% - getting only 75mm when asking
for 100mm.

> If it is always the same ratio of real distance to scanned distance 
> (also for -l and -t) it is most likely that the calculation of the 
> scan area is not handled correctly. That could be corrected by 
> changing the value of pos_factor in function set_window() in 
> snapscan-scsi.c. 

That would seem to be the case here.

> For the guy that developed the patch that didn't help, though.

Hm.  Is that the guy that you say below has the scanner working for him,
or is it someone else?

>> My main interest at this point is to understand whether this issue
>> is something that can be solved with some patch to the backend, or
>> whether it's inherently related to the scanner's firmware or
>> something that is Epson-proprietary that the SANE developers won't
>> get access to. Is anyone able to shed some light on this issue?  

> I don't think that this is an unsolvable problem. It may be necessary 
> to do some deeper analysis and maybe get some USB traces from the 
> windows driver, though.

How do I go about getting such traces for you (or whoever it is who'll
likely be working on this)?

> Also keep in mind that the scanner seems to work for at least one guy, 
> so the solution can't be that difficult :-)

I certainly hope that is the case!  What did that guy do to make it work?
I.e. scanning over the whole area?

(On a side note: Is brightness supposed to work for lineart mode?  As it
is, it tends to make Lineart mode scans too dark - things that are
clearly (but somewhat faded) white paper gets smothered in black.  My
UMAX Astra 1200 didn't have that problem at all.)

Thank you,

Bjorn.