[sane-devel] Custom Gamma Curves

[Martin Collins]

On Tue, 05 Nov 2002 22:28:04 +0100
Oliver Rauch <oliver.rauch@rauch-domain.de> wrote:

Hi Oliver

> >  When I'm adjusting the IRGB components in the histogram tool it
> >  would be nice to have the option of seeing just the selected
> >  components in the preview.
> For what do you need this, I do not find an advantage of this
> display mode.

I am trying to scan some old comics that have very yellowed paper. I
want to set the "whitepoint" for each color to the minimum required
to get a white background. With the colours mixed in the preview it
is hard to see where this is. If I could see just the blue (say) as
I adjust the "bluepoint" it would be clear when all the speckles in
the background disappear.

> man xsane:
>        The --Medium-calibration or -M flag enables a special mode of
>        xsane that can  be used  to  define  a  source
>        medium.   This mode should not be used for scanning images
>        because it may behave unexpected in several cases.

That's the ticket! I was so busy reading through the html docs I
forget all about the man page. "behave unexpected" sounds ominous
though.

Thanks
	Martin