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. |