Introduction
The Sketcher plugin can
transform digital pictures into simulated
hand-drawn sketches as well as special halftoning
effects. Here’s an overview of the controls…

The easiest way to use the
Sketcher is to apply the provided settings.
Clicking the Load
button in the Effect
Settings Section provides a file
selector where you can load any .sms settings
file, such as 'PenAndInk.sms' or 'NiceSketch.sms'.
Then click the preview
button to see what it looks like, and click
the Apply
button to apply the effect, or Cancel
to exit without changing the image.
The Sketcher Plugin works
on the illumination level within the image,
rendering light and dark areas, paying no
attention to the colour of an object. If
you apply it to a colour image without taking
the illumination into account, the results
may be rather bland. To illustrate the point,
here's a colourful picture of some balloons
to be given a sketch effect.

If the Sketcher's applied
straight away, the intensity level looks
very flat like this...

and the sketch result looks
similarly flat...

When applied to a colour
image, the Sketcher plugin shows the intensity
(grey image) in the Preview window. To get
nice sketch effects you need a suitable
source intensity image, generally with high
contrast and a high dynamic range. That's
easily provided with the colour manipulation
tools within your graphics application.
Just apply Brightness, Contrast, Gamma and
Histogram type processes before applying
the Sketcher Plugin. It is easier to see
the effect on the intensity by converting
your image to greyscale before using those
colour processing functions. For this image,
using the Transformation Curve function
with this curve...

a better intensity source
can be created...

which results in a better
sketch

Using the companion plugin
PhotoGrey, selectively filtering
the image can provide dramatically different
sources. Here's the result applying a red
filter and a slightly-green, blue filter...

Red filter applied
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Blue filter applied
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Of course, as well as using
the existing settings you can set up your
own sketch effects, but before you can do
that you need to know how the Sketcher plugin
works. |