Halftoning with Image-Based Dither Screens
Author(s): Oleg Veryovka, John W. Buchanan.
Proceedings: Graphics Interface (GI'99),
1999.
[BibTeX] 
Abstract:
Continuous tone images must be halftoned to be displayed
on binary output devices such as printers. The ordered
dither algorithm is a popular approach to halftoning.
This algorithm uses a threshold matrix to approximate
gray scale values. The arrangement of thresholds
in the matrix determines texture artifacts introduced into
the halftoned image. Thus, the challenge of research in
ordered dithering is to find a matrix that results in the
least visible texture artifacts.
In this work we control the halftoning texture by generating
a threshold matrix from an arbitrary image. We
demonstrate that processing images using adaptive histogram
equalization results in pixel distributions similar
to traditional dither screens. Ordered dithering with the
resulting threshold matrix enables us to define texture in
the halftoned image. We control the appearance of this
texture by a combination of the ordered dither algorithm
with an error diffusion process.
We present applications of the image-based dither
screens to both photorealistic and artistic rendering. In
the case of photorealistic tone reproduction this technique
preserves textures and edges of the original image. The
ability to define an arbitrary texture enables us to introduce
a variety of artistic effects. A halftoned image
can be embossed with another image, texture, or text.
Also, halftoning with textures clipped from the existing
art works approximates the look of traditional illustration
media.