Hi, > > 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.
Yes, so maybe it's enough to just change that value for the 3490. It's set in line snapscan-scsi.c, line 810. The value is currently set to 1600 for resolutions below 1600, 3200 for resolutions above. If your distances are off by 25%, try setting it to 1600/0.75 = 2130. > > 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? Yes. Unfortunately I've lost contact to him, i.e. he doesn't answer my mail. > > 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)? You can use usbsnoop: http://benoit.papillault.free.fr/usbsnoop/ The files tend to get very large, so chose a very small scan area and a low resolution. You can send them to me in private mail. > > 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? He developed the patch. His last mail stated it works, so I applied it to CVS. > (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.) Yes. The parameter is called "Threshold" in lineart mode. It's available in the Standard Options window in xsane or as option --threshold in scanimage. /Oliver
