A binary image is a digital image that consists of pixels that can have one of exactly two colors, usually black and white. Each pixel is stored as a single bit β i.e. either a 0 or 1.
A binary image can be stored in memory as a bitmap: a packed array of bits. A binary image of 640βΓβ480 pixels has a file size of only 37.5 KiB, and most also compress well with simple run-length compression. A binary image format is often used in contexts where it is important to have a small file size for transmission or storage, or due to color limitations on displays or printers.