Graph-Order Dither

This paper will be presented at Color Imaging XI, which is SPIE Conference 6058, part of the IS&T/SPIE 18th Annual Symposium on Electronic Imaging, 15-19 January 2006, San Jose, California, USA.

The full paper is available here. Below are some sample images made with the technique presented in the paper.

Gray ramp
This image uses Bayer-like dispersed dither. However, instead of replicating a fixed dither matrix across the original image, it randomly chooses one of 100 different dither matrices. The repetitive artifacts of Bayer's dither are avoided, but the potential parallelism of the ordered dither is retained.

Artistic Screen
Using graph-order dither, this image reproduces the technique in Ostromoukhov's paper "Multi-Color and Artistic Dithering" in Siggraph 99. Notice that the motif (a swiss cross rotated 45 degrees) must be specially constructed.

Source Image

Motif Image

Artistic Screen
This image uses an arbitrary decorative image as a motif screen. There is no need to prepare a special motif image.
The gray levels in the motif are each graph-ordered, and then the pixels for all the gray levels are concatenated into a single dither matrix.

Source Image

Motif Image

Artistic Screen
This image shows that an arbitrary binary image can be used as a motif.

Source Image

Binary motif Images