I\'m curious - is it possible to ahieve in PHP:
1) Send image file to server 2) Process image = detect edges and create simple strokes basing on the edges 3) Save fi
If you can use ImageMagick, there is the --charcoal filter:
The charcoal effect is meant to simulate artist's charcoal sketch of the given image.
The "-charcoal" operator is in some respects similar to edge detection transforms used by Computer Vision. Basically it tries to convert the major borders and edges of object in the image into pencil and charcoal shades.
The one argument is supposed to represent the thickness of the edge lines.
The ImageMagick examples manual shows another way whose results look even better:
Artist Charcoal Sketch of Image