I spent all the effort to get the Niash backend working on my SuSE 9.0 system. I'm using SANE 1.0.13 and XSANE 0.99. XSANE won't allow me to scan in greyscale or lineart mode; the selection box is simply not there.
Since the XSANE manual claims it should be there, I was wondering whether the backend can tell XSANE that it won't do b/w scanning. It's not quite clear to me why the selection box won't appear from reading the documentation.
I care about this because the Fax quality and the CPU load are rather unsatisfactory this way.
Any suggestions more than welcome!
In essence, XSane is a GUI for the sane-backends, so if the backend does not support greyscale or lineart, then Xsane cannot offer them either. This seems logical to me, so I don't really see the problem. If the Xsane manual says otherwise, then I think that part of the Xsane manual is wrong.
The niash type of scanners do not support greyscale or lineart scanning in their hardware. In the very latest sane package (1.0.15), there is a niash backend that does have support for grayscale/lineart. However this is emulated, which means that the scanner still sends full-color data, from which the backend produces b/w images. This means that scanning in b/w is not any faster (actually slightly slower probably because of the conversion) than scanning in color.
Thanks for shedding some light on this.
The manual does not say how xsane bahaves if the backend does not support the options. The manual just shows the select box without mentioning it could vanish in some cases.