Dithering is a technique to convert a grayscale image to black and white. It is used to create an illusion of the color which is actually not present. Dithering is done by randomly arranging the pixels.
Dither is applied in the form of noise to prevent quantization error.Dither is commonly used in the processing of both digital audio and video data. It is the last stage of mastering audio to a CD.
Below image have different levels of dithering.
There are three types of dithering methods:
In random dither, errors appear as a noise.
In ordered dither, error occurs randomly in the form of pseudo.
Error diffusion dither
In error diffusion dither, error occurs over in the neighbor pixel.