The picture in which each pixel has only two possible values or gray scale states, for example, the picture of an image processing system with the value of “0” (black) or “1” (white) only.; 每一象素只有兩種可能的數(shù)值或灰級狀態(tài)的圖形，例如圖象處理系統(tǒng)中只含有“0”(黑)或“1”(白)的圖形。