Dithering

Dithering, from the Middle English word “didderen,” literally means trembling. In digital photography, dithering is a technical term that describes the way in which noise, movement or other outside data affects the processing of digital information. While a person might assume that extraneous data would negatively affect the processing, in fact, dithering ironically reduces the amount of quantifiable error.

The effects of dithering were first noted during WWII when bomb navigation systems were found to function better in aircrafts than in ground testing. Researchers soon concluded that the small movements of the airplanes facilitated the turning of the various gears in the system. Instead of moving jerkily as they had on the ground, the gears moved more smoothly due to the plane’s movements.

In digital photography, dithering translates to the process of approximating colors not in the original frame. By dispersing the coloration encapsulated in the original pixels, the LCD screens on digital cameras can generate other colors.

While images that have undergone dithering appear grainy and blurry, they show the original image in better quality than those that are otherwise distorted and haven’t undergone dithering.