Seonglae ChoA technique for reducing the number of colors in an image while maintaining the original appearance
Sometimes you need to reduce the number of colors to save storage space or display images on older screens. Simply reducing colors creates distinct boundaries and flat "banding" artifacts. Dithering solves this problem by mixing pixels of different colors in a pattern, so that from a distance, they appear as intermediate colors.
For example, when there's no gray color available, mixing black and white pixels in a certain ratio makes the human eye perceive it as 'gray'.