Digital Halftoning is the process of arranging a pattern of dots to create the illusion of a grey-scale image. The histroy of halftoning dates back to seventeenth century print making technology of Mezzotint, which has evolved into classical screens and modern error diffusion, and blue noise methods. The successful creation of a halftone illusion requires a model of the display device (e.g., printer), and a model of how the human visual system perceives the image. Initial printer model using dot overlap and perceptual models using a Gaussian blurring kernel have improved the halftone quality. In this project, we make explicit use of perceptual concepts such as edges, scale, color, and texture in the modeling how a halftone is perceived. This project is in collaboration with Astro-Med Inc. 

original	cluster-dot dithering	blue noise screening
JJN error diffusion	Least-square model-based	Our method