[Digikam-users] Can't reduce saturation of only 'Red'.

[Photonoxx]

Anyway, something seems a little not inaccurate for me. I don't think it's  
possible to reduce saturation for the red channel only, since the  
saturation result of the proportion between different channel. So there's  
no truly a reduction of the red saturation value, but a reduction of the  
saturation, only applied on a mask which contain pixel with a certain hue.

I test Gimp tool on a picture with a pink cloth, if i selected red in  
place of master channel, and set the saturation to 0, there's still some  
spots unaffected which are more associated with magenta "channel", so it's  
not really a reduction of the saturation of a channel, but of a range of  
hue original value.

But at the end, it's anyway the result the main thing ;>)

Nicolas

Le Tue, 07 Sep 2010 06:59:31 +0200, Gilles Caulier  
<caulier.gilles at gmail.com> a écrit:

> Open a new file in bugzilla about this wish...
>
> Gilles Caulier
>
> 2010/9/7 jag59 <jldeshpande at gmail.com>:
>>
>>
>> jag59 wrote:
>>>
>>> In editor, with Color> Hue/Saturation/Lightness>Channel Red (in the
>>> drop-down list), I can not reduce saturation of only 'Red' channel.This
>>> reduces saturation of all channels in spite of selecting either  
>>> Luminosity
>>> or Red or Green or Blue in the drop-down list.
>>> My Nikon D40 gives much saturated (red) skin in portrait mode.Is there  
>>> any
>>> way to achieve this?
>>> Reducing level of red is not useful as we need to reduce only saturated
>>> reds, not all reds in the image.
>>> Reducing 'Temperature' in 'White Balance' overexposes the image,but  
>>> seems
>>> this is the only solution presently.
>>> In many tools,selecting one among Luminosity,Red,Green or Blue from the
>>> drop-down menu does not make any difference besides showing graph for  
>>> that
>>> color.
>>>
>>
>> At last I found  the solution,though not direct but can say a  
>> workaround.
>> In Color>Hue/Saturation/Lightness......reduce saturation to @ (-)40  and
>> then increase vibrance to 70.This attends the over saturated skin tones
>> without affecting other colors.
>> This  gives almost same results which I get in GIMP by selecting 'red
>> instead of default master' in the 'hue-saturation tool' and reducing  
>> it's
>> saturation.
>>
>> Hope in future version the sliders in H/S/L tool will work only on  
>> selected
>> channel.
>>
>> Regards.
>>
>>
>>
>>
>> -----
>> Jagdeesh Deshpande.
>> Registered Linux user #492893
>>
>> --
>> View this message in context:  
>> http://digikam.1695700.n4.nabble.com/Can-t-reduce-saturation-of-only-Red-tp2332476p2529053.html
>> Sent from the digikam-users mailing list archive at Nabble.com.
>> _______________________________________________
>> Digikam-users mailing list
>> Digikam-users at kde.org
>> https://mail.kde.org/mailman/listinfo/digikam-users
>>
> _______________________________________________
> Digikam-users mailing list
> Digikam-users at kde.org
> https://mail.kde.org/mailman/listinfo/digikam-users


-- 
Nicolas Boulesteix - Chasseur de lueurs - http://www.photonoxx.fr