Weighted Voronoi Stippling
Author(s): Andrian Secord.
Proceedings: 2nd International Symposium on Non-Photorealistic Animation and Rendering (NPAR'02), pp. 37--43, Annecy, France, June 3-5,
2002.
[BibTeX] 
Abstract:
The traditional artistic technique of stippling places small dots of
ink onto paper such that their density give the impression of tone.
The artist tightly controls the relative placement of the stipples on
the paper to produce even tones and avoid artifacts, leading to long
creation times for the drawings.
We present two non-interactive techniques for generating stipple
drawings from grayscale images using weighted centroidal Voronoi
diagrams. An iterative technique acts on input images directly
to produce high-quality stipple drawings and a real-time approach
uses precomputed dot distributions to stipple images quickly.