I have read a number of posts on the topic and it seems that for now it is not possible to use sane to read infrared data (second pass) with my Epson Perfection V700 scanner out of the box.
But are there any options to get that working? Any known patch? Any configuration behind the scenes? Any undocumented feature?
I just asked the question on Avasys' message board, but if any of you guys out there had relevant information, I would appreciate greatly.
Of particular interest is the 6400dpi resolution in 16bits per channel to scan slides, so I need the infrared option on the
epkowa driver as the
epson2 driver seems limited to 3200dpi anyway.
As far as I can tell neither
epson2 offers the infrared scan, though it seems that it should be a simple option (
vuescan actually can do the job, it does two scan passes, one for the RGB and one for the infrared, but I would much prefer to be able to do my scans from the command-line).
Note that I don't mind if the infrared scan comes out as a separate image, I can manage to combine them as needed.
Also of interest and not included in the current
sane-epkowa driver are:
1/ scans with multiple samples
2/ confirmation that the
-brightness setting actually changes the CCD exposure time (rather than performing software image processing)
Edit 2011-02-01: check sane-devel for the start of an answer.
sane-backends v1.0.21 has code that's unused by default. A tweak in epson2.c to enable my scanner (GT-X900) and a configure option to enable IR (CPPFLAGS=-DSANE_FRAME_IR) gets me a version that can at least pretend to do the job.
I still have to solve two significant issues before I can call it a victory:
1/ with --mode=Infrared, the output image format seems incorrect, it seems like it produces grayscale, albeit in a funny format.
2/ --mode=Infrared does not actually produce IR data, the data looks like Grayscale from ordinary colour, it does not look like the result of an Infrared scan.
More tweaking will be necessary before I get the desired result.
Again, if any of you has any idea that would help debug and fix (such as where to start in the code, debug settings...), please shout.