A method and system for classifying images between natural pictures and synthetic graphics is provided. In embodiments of the invention, a picture/graphic classification method and system implements one-dimensional color discreteness features, two-dimensional color discreteness features, or three-dimensional color discreteness features for image classification of natural pictures and synthetic graphics. In another embodiment of the invention, a picture/graphic combination classification method and system implements one-dimensional color discreteness features, two-dimensional color discreteness features, and/or three-dimensional color discreteness features is used to classify images between natural picture and synthetic graphic classes.