Match Color feature - white balance on skin tones

[Beep6581]

Originally reported on Google Code with ID 1773

It would be nice to have a "Match Color" feature. 

It could be implemented by selecting a color in a photo, switching to a different photo,
selecting the area to match and then RawTherapee would change the color tones in the
current image (at the selected point) to match those in memory (from the first image).

It would simplify making skin tone consistent from one image to the next, for instance.

Specifically, the code would be very similar to setting white balance, except that
two samples are taken and the second sample would be normalized to the first, instead
of neutral (as in WB). All other tones would be translated by the same values as used
to normalize the second sample.

If this is too difficult to implement, maybe think of it like a sampled "memory color",
where you use a dropper to sample the color from a reference image, and then a second
operation sets the sampled color onto the image area to be corrected. It would be nice
if the corrections were somewhat limited in tonal scope, so that white and black neutrality
remains.

Reported by ziggggy53 on 2013-03-12 03:49:06

[Beep6581]

Related forum: http://www.rawtherapee.com/forum/viewtopic.php?f=2&t=873&p=30460#p4292

Reported by entertheyoni on 2013-03-12 08:08:24

• Labels added: Type-Enhancement
• Labels removed: Type-Defect

[Beep6581]

When I shoot landscape winter images matching the color of snow is a common task that
could be helped by this feature

Reported by torger@ludd.ltu.se on 2013-10-26 21:37:49

[Beep6581]

skin balance. 

It's a nice start .. 

http://www.magiclantern.fm/forum/index.php?topic=9469

Reported by iliasgiarimis on 2013-12-08 17:10:59

[Beep6581]

Issue 1159 has been merged into this issue.

Reported by entertheyoni on 2013-12-08 17:30:39

[Beep6581]

This seems to be getting lost. RawTherapee could really benefit from this feature, and
it would distinguish RawTherapee from other similar applications.

It should also be possible to sample and evaluate skin tones to make sure that they
fall into plausible values. If they don't fall into typical values, then color-corrective
remedial actions could be applied.

Analysis of sampled human skin tones, their RGB values and ranges, and some rudimentary
RGB formulas here:

http://johnthemathguy.blogspot.com/2013/08/what-color-is-human-skin.html

Thanks all.

Ziggy

Reported by ziggggy53 on 2014-04-02 18:28:38

[Beep6581]

Re #5: There already are some settings concerning skin tone protection in RT. Jacques
can give more detailed information.

Ingo

Reported by heckflosse@i-weyrich.de on 2014-04-04 22:58:17