### 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 |
Blue filter applied |
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.