[G'MIC] New filter 'Colors / Curves [interactive]'

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Hi there,

I've coded a new filter for the G'MIC plug-in, trying to extend the color curves tool for many more colorspaces, including Lab, HSV, CMYK, etc..
If you have at least the version 1.6.0.1 of the plug-in, you can access it after updating your filters.

I've recorded a very quick video to show how it works (here, for a curves manipulation in the CIE Lab colorspace) :

Video from : www.youtube.com

Once you are happy with your curves, you can add this filter to your Faves, and the color preset will be remembered next time.

Let me know if you find it useful !

Carlos Diniz · **Joined:** Jan 20, 2013 **Posts:** 590

Ronounours, please, from which link can Iget the installer for version 1.6.0.1 of G'MIC for Win32? At the official website of G'MIC there is no indication on the version.

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

This link shows under the black bar at the top that this is the stable version of 1.6.0.1
The top one would be for windows 32 and 64
http://gmic.eu/

Carlos Diniz · **Joined:** Jan 20, 2013 **Posts:** 590

Thanks, Molly.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Carlos, all versions available in the G'MIC web site are at least 1.6.0.1 for the proposed architectures.

Carlos Diniz · **Joined:** Jan 20, 2013 **Posts:** 590

Thanks, Ronounours

YAFU · **Joined:** Nov 09, 2011 **Posts:** 726

The possibility of having interactive filters on G'MIC is really wonderful. This has great potential. Thank you David.

Do you know about Darktable? If you could implement Darktable Equalizer (Luminance/Chrominance/Edges) and Color Zones filter would be great

Playing with the filter (plus vignetting):

http://pixabay.com/es/punta-trigo-cerea ... ampo-8742/

lylejk · **Joined:** Sep 24, 2010 **Posts:** 12775

Looks cool indeed. Hopefully someone can come up with some cool presets like Photochrom.

Odinbc · **Posted:** Fri Oct 10, 2014 11:04 am **(#9)**

Curves [interactive] is exactly what I wanted David. It's way better than going the decompose/recompose route for channels adjustments and these Interactive methods are excellent to work with.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Thanks Odin.
And the very good thing (in my opinion), is that you can also output a so-called 'CLUT' file, which remembers all your color transformations, and which can be used in other softwares as well (e.g. RawTherapee).
If you have nice color presets you've done and you want to share, then this is a convenient way (albeit not the smallest one) to do it. Just save the CLUT file and share it with others. G'MIC has also a filter to apply an arbitrary CLUT file (located in 'Film emulation/' if I remember well).

himppu · **Joined:** Jan 25, 2014 **Posts:** 78

This is a great filter!

I've played with it this morning.
Thank You!

Graechan · **Posted:** Sat Oct 11, 2014 1:35 am **(#12)**

David your spoiling us with all these fantastic Gmic interactive goodies, Thank you for turbocharging Gimp

Rod · **Joined:** May 16, 2010 **Posts:** 16023

This is simply amazing David. Thank you for adding these interactive window filters. They are fantastic.

K1TesseraEna · **Joined:** Sep 22, 2012 **Posts:** 2089 **Location:** US

Thanks David!
You are making a good use of the interactive window. Love this new gmic feature as I said before.
Curves is a powerful tool. I use it to make a tonal and color corrections, even prefer Curves to Brightness/Contrast
tool to make corresponding adjustments.

A few suggestions that I believe would make the new filter even greater.
1. Clicking on image would create a curve point on each separate channel curve. Say you can assign LMB click
for color picker sampling and leave RMB for before/after split view. Well, this is a very important functionality in the Curve tool*.
2. There's gotta be a way to reset curves to the initial state without closing interactive window.
3. The possibility to delete points.
4. [very optional] Sampling shadows, midtones and highlights (aka black, grey and white points)

* It's too long to explain. E.g. I can make color adjustments selectively (kind of) of make it locally based on the sampled tone/color.
The new Curves tool reminded me of the Curvemeister plugin for PS. Maybe watching this video is a fastest way to explain what I mean.

P.S. At 1:30 of that video the guy makes some wrong assumptions about PS curve tool.
Actually, the CC version of PS has some added functionality.
This is odd, because the video is dated April 2014 and CC version was around for almost a year back then.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

1. Adding new curve point from the image is indeed a very good idea, I'll add it (right button probably).
2. Press key 'R' on the curve window to reset a curve. This is already implemented.
3. Click with right mouse button on a control point to delete it. This is also already implemented

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

Amazing David, thank you

K1TesseraEna · **Joined:** Sep 22, 2012 **Posts:** 2089 **Location:** US

awesome! thanks!

MichaJo · **Joined:** Nov 21, 2011 **Posts:** 28

This is really great! Thanks!
But i've got a problem. I'm still on Windows XP (Professional SP3). Probably that's to blame for the error i get after clicking OK (png-image, colorspace Lab).

*** Error in ./gimp_curves_interactive/*if/../*if/*thread0/*local/rgb2lab8/ *** Command '-rgb2lab': [instance(504,756,1,1,06D40020,non-shared)] gmic<float>::RGBtoXYZ(): Instance is not a RGB image.

This doesn't happen all the time. Sometimes the filter works with a fresh opened GIMP. Sometimes it doesn't.

(Sorry if this is not the right place to post this)

Michael

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Maybe your png has an alpha-channel ?
This should not be a problem anyway, but I'm just trying to guess

MichaJo · **Joined:** Nov 21, 2011 **Posts:** 28

Yes, it has. With removed alpha channel it works like a charm.