### Producing colour sketches Although the Sketcher plugin only works on the intensity of an image, it can be combined with the other functions in a graphics program to add more artistic options to your graphics. The following will show how an average photograph can be easily turned into an artistic portrait sketch.
From this source photo | To this colour sketch
With this as a starting image, the first thing to decide is how you want the final sketch to look. If we want a general sketch we will want strokes covering the image. If we want a contrasted sketch, we will want strokes only in the areas we want to highlight. In this example a contrasty sketch highlighting the red hair is desired, so we'll need more/darker strokes in areas of red. To get the right source material, the image source intensity needs to be processed in such a way to highlight the material wanted. By using the companion PhotoGrey plugin, selecting a slightly green blue colour keeps the reds dark, producing this source material... This has kept the hair dark. To increase contrast use the Histogram functions or other image processing functions of your graphics package... Then convert it into a pencil sketch using the Sketcher plugin. In this case the default settings of NiceSketch.sms work well... This image is then pasted as a new layer over the old image, and the blending type set to Screen. The colour image underneath only shows through where there are strokes... As a final bit of artistic processing, the underlying image can have it's saturation increased and brightness decreased, to look like this...
Increased saturation and decreased brightness... | ...adds more life to the final colour sketch
By using different level blend modes, different styles of sketch, and different contrast in the source images, you can experiment in finding different effects.