Image Pencil Effect

Level steps: 2 3 4 5 6
Line alpha: 0.05 0.1 0.2 0.5
Line thickness: 0.5 1 2 3 5 10
Line density: 0.25 0.5 1

Greyscale output image


Lightness: 1 2 4 8
Edge thickness: 2 3 5 10
Edge amount: 0 0.5 1 2