[sane-devel] newbie

Andy Bennett andyjpb at ashurst.eu.org
Mon Jan 25 17:48:33 GMT 2021


> Regarding the colors of the iX500, they are not strictly raw data. The
> scanner self-calibrates, which removes most of the high frequency
> noise. But, the default brightness and contrast values may still need
> some manual tweaking. It is also possible that the windows software
> does some further enhancement, which is not done in the sane backend.

Thanks allan!

The calibration is really noticable, especially if there's any dust on the 
glass. There's always been a slightly lighter stripe on the back sensor 
that won't seem to go away and it's easy to see the bits of the paper that 
are held slightly closer to the head by the rollers.

Fixing the gamma gets rid of most of it and tweaking the white point gets 
rid of the rest. ...but it seems to be almost a bit's worth of data in each 

I've never used the Windows software; I just took the PNM files, converted 
them to PNG, verified they looked exactly the same as the PNMs in Gimp on 
Linux and then transfered the PNGs to Windows where I looked at them with 
the built-in viewer.
I guess the Windows viewer does its own gamma correction or something? Or 
perhaps it's the other way around?

Best wishes,

andyjpb at ashurst.eu.org

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