A binary image is a digital image that has only two possible values for each pixel. Image:LennaBinary.png Binary images are also called bi-level or two-level. (The names black-and-white, B&W, monochrome or monochromatic are often used for this concept, but may also designate any images that have only one sample per pixel, such as grayscale images.) Binary images often arise in image processing as masks or as the result of certain operations such as segmentation, thresholding, and dithering.