The mirage problem in digital halftone resolution

Abstract

Generating realistic images is a challenging problem in computer graphics. The last stage of many graphic tasks is the production of a continuous tone picture often on a bilevel display. As a result, an algorithm to map continuous tone intensity data to bilevel data is required. This paper examines the ordered dither and Knuth's dot diffusion algorithms and constructs a mi­ rage for both these techniques, that is, an image which is recognizable under a special display technique but which vanishes completely when displayed using either ordered dither or dot diffusion. Finally, we conclude that there is still more work that could be done in the field of reproducing halftone images.