This GIMP (GNU) tutorial demonstrates how to apply GIMP’s Decompose Filter to remove an image’s colour. To work along, you are welcome to download the Start Image I am working with Here. Unzip the file and open the image onto GIMP’s workspace.
You can quickly Undo a step at any time by pressing Ctrl then Z. Alternatively, click a previous Undo History snapshot - Windows then Dockable Dialogues then click Undo History. In addition, to Zoom in (or Zoom out) of your image; from the top menu choose View then select a Zoom Tool from the subsequent drop-down list.
Launch GIMP & Organise Its Workspace & Palettes
Open your choice of Start Image onto GIMP’s workspace - File then Open - Ctrl then O.
Ensure the Layers and the Undo History Palettes are visible, and then drag them into position over your workspace - (Windows then Dockable Dialogues - then click Layers and Undo History).
Now, from the top menu, choose Colours then choose Components then choose Decompose. And from the subsequent Decompose dialogue box, enter the following settings, or experiment, and then click OK.
To create extra impact, apply a Sharpening Filter of your choice - Filters then Enhance.
Congratulations, your Decompose Colour removal is complete, and it is ready to save - top menu, then File then Save As. GIMP 2.8 - File then Export.
Wendi E. M. Scarth. Top of Page.