Creating the illusion of new colors and shades by varying the pattern of dots. Newspaper photographs, for example, are dithered. If you look closely (see example below), you can see that different shades of gray are produced by varying the patterns of black and white dots. There are no gray dots at all. The more dither patterns that a device or program supports, the more shades of gray it can represent. In printing, dithering is usually called halftoning, and shades of gray are called halftones. 1
Legal Electronic Document Institute, Basic Principles of Automated Litigation Support (2005).