Abstract
Stippling is a basic class of non-photorealistic rendering (NPR) graphics. The NPR stippling images are monochromatic binary ones where black dots are distributed over white backgrounds. In this paper, we extend their composition and present methods for producing monochromatic multi-valued stippling or color stippling images. Our method is based on the scheme of point redistribution according to probability distributions presented by Secord et al. We extend their scheme and apply it to stippling with multi-valued dots over multi-valued backgrounds and to color images. Additionally we devise a scheme for improving detail description with varying dot sizes according to the gradient of tonal intensities in input images.
