Exploiting texture effects in dithering
Kenneth R. Sloan, Yun Wang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
This paper presents a method of dithering which attempts to exploit the inevitable textures generated by all dithering schemes. We concentrate on rendering continuous tone (monochrome or color) image on a CRT display with a small number (on the order of 16 - 256) of distinct colors. Monochrome (especially bi-level) dithering techniques are well studied. We have previously demonstrated that texture introduced by the dithering process can significantly affect the appearance of the image. We then developed a scheme by which the user had some control over these texture effects. The primary tradeoff was between very fine grained textures which depend critically on the local gray level and relatively coarser, more obvious, textures which appear uniform across the entire image. In this paper we try to actively exploit the texture effects to enhance the appearance of the rendered image. The key idea is to use our previously described hybrid method (which combines ordered-dither with error diffusion) but to choose (locally) different ordered-dither matrices based on measured properties of the original image (e.g., the local gradient). We also show how to use anisotropic error diffusion to generate similar texture effects.