[sane-devel] XScanimage: Gamma function bugs

[Oliver Rauch]

Andre Herms wrote:
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> Hi,
> 
> If you select a gamma value < 1 in xscanimage, you get an inverted output.
> White <-> Black.
> Maybe is because the output values get negative. If I correct the function by
> hand - it works.
> 
> I don't know, who's responsible for this, so I use the Sane mailing list.

I think this is a bug in the gtk_gamma functions.
But it does not swap black and white, only the last value (e.g. 255)
sometimes is not set to 255 but to 0. There is another bug in the
gamma function, the number of used colors is defined by the number of pixels
(horizontal direction) of the gamma widget.

The problem is that no one in the gtk team cares about that.
Someone (I don`t remember his name) corrected the buggy routines
and contacted the gtk team / mailing list but no one did ever answer
his reqeuests.

Bye
Oliver

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