Half Toning and Error diffusion

Image halftoning converts a high-resolution image to a low-resolution image, e.g. a 24-bit color image to a three-bit color image or an 8-bit grayscale image to a binary image, for printing and display. In error diffusion halftoning, the quantization error at each pixel is filtered and fed back to the input in order to diffuse the error among neighboring grayscale pixels. Grayscale error diffusion introduces nonlinear distortion (directional artifacts and false textures), linear distortion (sharpening), and additive noise