Le mardi 05 septembre 2006 ? 20:29 +0200, Oliver Schwartz a ?crit : > Hi, > > > > When I try to scan in lineart mode, it makes garbage on output. > > > The scan seems "misaligned". > > > But if I first make a scan in gray or color mode, and then switch > > > to lineart, it works ! > > > > It works ... sometimes :( > > > > I acquire a scan in Lineart mode and make a log : > > http://www.starox.org/pub/sane/snapscan/lineart.log > > It makes dirty squares in the image : > > http://www.starox.org/pub/sane/snapscan/lineart.pnm > > So... is this the best result you can get or does it work ok (without > the dirty squares) if you scan in grayscale first? It is the best result I can get with scanimage. It always fails. Whereas with xsane, sometimes it works after a real scan (not a preview, but after a preview). Maybe a problem with preview ?
> Unfortunately it seems that lineart mode is less and less supported in > newer scanners. These scanners always scan in grayscale mode, the > conversion to lineart has to be done in the backend. I don't know if > this is the case for the Perfection 660, but on the other hand > there's not much that can fail on lineart mode. So, it's possible to fallback to software conversion. It seem's there is many scanner with this problem, maybe we can add a new option for this ? > Maybe you can provide an USB trace of a lineart scan on windows. > You need to install an USB sniffer first. I prefer USBSnoop which is > available from http://benoit.papillault.free.fr/usbsnoop/ . The page > also gives basic instructions on how to use it. > [...] I'll do this tomorrow.
