The Painterly Approach
Wasinee Rungsarityotin, Victor Zordan.
Georgia Tech. - (Project: Advanced Topics in Rendering),
1996. [BibTeX]
The Virtual Painting Paintbox
Dominique Sobczyk, Vincent Boyer, Jean-Jaques Bourdin.
Short Presentations, Eurographics 2003,
2003. [BibTeX]
Turning Images into Simple Line-Art
Samuel G. Noble.
Undergraduate Thesis, Reed College, December,
2001. [BibTeX]
Varieties of Digital Painting
Author(s): Alvy Ray Smith.
Misc: Tech Memo 8, Aug 30,
1995.
[BibTeX] 
Abstract:
The purpose of this memo is to distinguish between the various meanings that digital painting may have. It is important to have a taxonomy so that intelligent conversation may proceed on such important issues as multi-resolution paint programs. Each type of painting will be discussed in its multi-resolution generalization. The taxonomy here splits painting into discrete and continuous categories and each of these into maxing and non-maxing subcategories.
VelvetPath - Layout Design System with Sketch and Paint Manipulations
Hiroaki Tobita.
2003. [BibTeX]