I have an image that has areas with different colors in them similar to this
I would like to draw a line at the boundary between the red and the blue regions using Gimp. So the end result might look something like this
I can select one of the two regions with the Select by Color Tool, but then I don’t know how to draw the edge of the selection.
- Choose black as the foreground colour
- Select the Brush Tool. In the tool options underneath the toolbox, set the Hardness to 100%, and size to something like 10.
Use the Fuzzy select tool (Magic Wand) or the Select by Colour tool, to select the blue area
Do Edit > Stroke selection, choose the “Stroke with a paint tool” option. Click Stroke.
Do Select > None (Shift+Ctrl+A)