Is it possible to make the popup help more informative on this point? Like maybe:
"Do a quality (rather than quick) internal white-calibration"
The point is to distiguish it from calibration on the image. You can decide if
this is necessary since the real problem here is that my scanner just
doesn't have a very good white point whether it's calibrated carefully or not.
Sounds like this option adresses the problem of vertical streaks more than my
problem, so maybe it should say something more along those lines, I don't know.
> Xsane makes available the highlight and shadow function via the hystogram window.
> Open the histogram window, between the two histograms there are some colored blocks.
> In the recent version there are three sliders in the gray block. Move the mid slider
> and
> the left slider to the right, as far as possible. Then do a real scan of the image.
> On a preview
> you will not see any differences, because the preview is always done in 24bpp, the
> real
> scan uses a 36bpp and afterwards converts it to a 24bpp image.
>
> I hope this works for you!
Actually this helps a lot! Thanks for the pointer. The scan comes out actually
useful though it's still not as good as the one done on another scanner. I'm kinda
new to scanning so I don't know many tricks yet.
> > I think I could do better if I had an idea what I was looking for. What is
> > the Quality Calibration supposed to work like? Should it happen at the
> > beginning of each scan when the button is checked? Should the scan process
> > be different? A two pass scan maybe? If it's not working is this because
> > the driver is just not telling the scanner to do it properly? Is this
> > documented anywhere or is this a trial and error type thing?
> >
>
> The difference is in the short time before the real scan begins.
> If you don`t see any differences, it is possible that the scanner
> always does a quality calibration independent from the quality bit.
>
> May be you see/hear a difference between a preview scan and a
> real scan.
I see now it now. It's like a really short scan just before the actual scan. I
wasn't seeing it before because it only does it the first time you scan with it on
after a scan with it off. I was always checking in the wrong order by doing a
scan with it on (after having just done one with it on) and then one with it off.
Apparently the firmware is intelligent and doesn't redo the quality calibration if
it has just been done on the previous scan, or something like that.
In the end I have decided the white point on this scanner is just not so good for
whetever reason. I can put in something white and something slightly off-white
and even using only the top half of the values as described above they both come
out completely white, indicating the scanner can't see the difference between
them. Oh well that's why it's not an expensive scanner I suppose (I use it mostly
for 1-bit scans of text anyhow), though I really have no way of knowing if it's
the model or just this one scanner.
Thanks for all of your help Oliver, and thanks for your work on the software!
-Dean Townsley
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