Dither 

By Inkjet Insight / Published:

In digital imaging, to use the values (colors) of two pixels to determine the color of a pixel lying between them. This new pixel thus has a value that is the average of the two pixels on either side of it. Dithering is often used to eliminate unwanted jaggies (i.e., to give an image a smoother edge), or to determine the value of certain pixels when reducing the color depth of an image, as when converting from 24-Bit color to 8-Bit color. The term dither also means to change a range of grayscale values to patterns of black-and-white by placing white and black dots in such a pattern as to simulate or suggest a range of grays.