On Mon, Sep 21, 2009 at 6:26 PM, Noel Stoutenburg <mjol...@ticnet.com> wrote: > Friends, > > I'm trying to figure the best way to use GIMP blend colors in a > particular application. > > I have a topographical map, and I want to apply a color gradient which > follows the contour lines of the map, and blends from a darker hue at
BTW: I don't know what 'a color gradient that follows the contour lines' means, I could only guess. If my advice is not suitable for what you mean, I suggest clarifying. > the lower contour to a lighter hue at the next higher contour. The > contour lines are not parallel. In the final image, I want a uniform > darker hue right next to the contour line, and a uniform ligher hue at > the higher one. A further complication is that the contours do not have > a uniform direction. In one part of the image the gradient from 10 units > to 20 units will be right to left, in another part of the image going > from 10 units to 20 will go from left to right, and in still others, the > contour representing 20 units will be a smaller irregular shape inside > the larger, different, but still irregular shape representing an > elevation of 10 units. > > I've thought of a number of ways to do this manually, for example, > divide the map into different layers at the contour lines, and using the > airbrush tool to overlay the colors; another is to leave the different > contour levels in one layer, and use the smudge tool to blend across the > contours. But are there filters of plug-ins which might automate at > least part of the process? The built in edge detection filters may help you in creating a suitable selection to apply darkening to. For the basic colorizing , I think you want the Gradient Map filter (Colors->Map->Gradient Map) Hope that helps _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
