I would try with a "drawn & Parametric mask" blend mode on the Monochrome module.
On the parametric mask use hue or a/b sliders to isolate the main color (hint: input slider). You may also set lightness and chroma for fine tuning, but probably there is no need. Use the mask preview. It's easier to select and then invert the masks in this case. Add just a little mask blur. Also use the "Color picker" tool (the one inside the parametric mask ui), in area mode, to help you locate the color/tone you are looking for: the small indicators will give you a good starting point. Then draw a few masks, brush or path, to roughly isolate the elements. Even if you cannot see that specific color in other parts of the pictures is there too and you'll end up with a small hint of that color in other places otherwise. If you are going for something like green, where you have grass and tree leaves create multiple instances of the monochrome module and use one for each tone, otherwise you need to widen too much the color range picking up about everything or leaving holes. An alternative is the color zone module. Saturation tab, drop down everything else. Add a few masks, even parametric, for fine tuning. https://www.darktable.org/usermanual/ch03s02s08.html.php https://www.youtube.com/watch?v=x1RRaXbnixQ Lorenzo 2017-01-16 16:30 GMT+01:00 Anton Aylward <li...@antonaylward.com>: > My Sony camera has a "picture" setting that produces an image that brings > out > one primary color and makes the rest of the scene B&W. You've probably > seen > this kind of effect in advertising. > > The downside of using this in-camera option is that it (a) only works for > the 3 > primary colours and (b) only works in JPG mode, not RAW. > > I prefer to use RAW and post-process since I can also do things like deal > with > skylines and shadows, so I wonder how I would do this in DT after I've > done that > basic processing. > > If this is a single discrete object such as a red sport scar in the midst > of > otherwise banal traffic, such a I've seen in adverts, then its easy enough > to > crop. But there are many situations where the colour you want is > distributed, > perhaps the green of trees on a street scene. > > As I say, this only works for primary colours. I can think of a few > photographs > I've got where I'd like to apply this technique but the color I want to > bring > out isn't primary. > > Other then simply killing the green and blue in a color profile, what can > I do > about the sport car scene? or red and blue in the trees in the street > scene? > > > -- > Rule of Feline Frustration: > When your cat has fallen asleep on your lap and looks utterly > content and adorable, you will suddenly have to go to the bathroom. > ____________________________________________________________ > ________________ > darktable user mailing list > to unsubscribe send a mail to darktable-user+unsubscribe@ > lists.darktable.org > > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
