Display curve node input/output values

[Beep6581]

Originally reported on Google Code with ID 2610

I think the Curves Tool (Exposure Panel, Lab Adjustments, etc) need a textboxes with
the input-output values of each node of the curve. This is a very useful improvement
for a fine curve design when we work with step wedges o densitometric scales, where
we work with numeric values as a output and the eyedropper for pick input values from
the image.

This textboxes are a common tool in the most raw developers and image editors because
are very useful (may be imperative) for a fine tunning or design of tone response curves.

Thanks

Reported by info@jpereira.net on 2014-12-18 00:36:25

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• Attachment: curvas.png
  

[Beep6581]

This:

"Regarding the tone curves in the Exposure tool, despite you seeing the R, G and B
histogram (merged) in the background of the curve, the curve operates on luminance
values, where Relative Luminance Y = R*0.2126729 + G*0.7151521 + B*0.0721750 (See https://en.wikipedia.org/wiki/Relative_luminance
) First the relative luminance value of the node is obtained, the curve is applied
to that value, the multiplication factor between before and after luminance is calculated,
and then this factor is applied to each R, G and B component, compared to applying
the curve to each component separately in the separate RGB curves in the Color tab.
"

...should not be part of the explanation of the curve editing process, but part of
the "Curve mode" section here http://50.87.144.65/~rt/w/index.php?title=Exposure

Reported by natureh.510 on 2015-06-08 18:15:22

[Beep6581]

Ah! Done. Please check and close this issue if it's fine.

Reported by entertheyoni on 2015-06-09 07:34:44