and computer graphics
The process of converting an image
to use a very small number of predetermined pixel
types, by forming patterns of these pixels. For instance, given red
pixels, we can generate magenta
-like areas in the output image by placing red and blue pixels next to each other.
The most common type of dithering represents a black and white image with just 2 pixel types: black and white. This is useful for printing out the image.
Newspaper images are usually also printed using just black and white dots; however, the process there is an analogue (non-computerised) process known as halftoning. The results there are usually similar to ordered dithering, but with a rotated halftoning screen.