[Gimp-user] Picking Gray Point in a Photograph and recalling pixel points

[laptop]

< snip >
> 
> > Have a look at Sample points dialogue.

> This looks like it might be it :-)
> 
> First, I was able to select a "sample point" per the instructions in
> the documentation (drag a ruler w/the ctrl key down), but the Sample
> Points Dialog did not come up. The documentation said it might not,
> and that you had to open it separately.

I also have to open the sampled point dialogue which I have docked from
'Dockable Dialogues'.
> 
> 1) Does anyone know why adding a sample point might not open the
> Sample Points Dialog automatically?
> 
> Second, with the sample point selected, I opened the Levels Tool. I
> want to use this sample point as the "gray point". In the Levels Tool,
> I clicked the "Pick gray point" eyedropper, and then went to click on
> the sample points, but the only thing that happened was the cursor
> changed from an eyedropper to an eyedropper+move_symbol, which means,
> according to the status message at the bottom of Gimp, I can move the
> point, but I can't seem to use it.
> 
> 2) Now that I have a sample point (the gray point), how do I use it in
> the Levels Dialog?

I thought I had explained that but just to re-iterate in the Levels
dialogue select the colour channel of the colour cast and reduce its
intensity, following the changes in the sample point dialogue.

Norman