Texture-based dither matrices

Continuous tone images must be halftoned to be displayed on binary output d evices such as printers. Halftoning algorithms at low resolutions of the ou tput hardware introduce textures into the resulting display. In this work w e control halftoning texture by generating a threshold matrix from an image -based texture. We demonstrate that processing textures by the adaptive his togram equalization algorithm approximates pixel distribution properties of 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 algorith m with an error diffusion process. We present applications of texture-based dither screens to both photorealistic and artistic rendering. In the case of photorealistic tone reproduction our technique preserves textures and ed ges of the original image. The ability to define an arbitrary texture enabl es us to introduce a variety of artistic effects, including embossing of im ages with textures and text. and approximation of the appearance of of conv entional illustration media. We evaluate the resulting halftoning using mul ti-scale edge distortion measures. Our quantitative evaluation closely corr esponds to the visual observations.