Image processing is a field distinct from the rest of computer graphics. It describes how digital images can be manipulated mathematically. Image processing is also called image filtering, a term that originated with the use of filters in photography. Digital filters tend to be more capable and precise than their physical counterparts. The terminology persists, however; when we look at the BufferedImageOp interface, you'll see that its central method is named filter().
This chapter describes image processing in the 2D API. First, I'll talk about the new image processing model in the 2D API. After that, there's a long example that demonstrates 2D's image processing capabilities. The remainder of the chapter is a sort of cookbook that describes the types of image operations that are included in the java.awt.image package. I'll explain each operation briefly in mathematical terms and try to show its effect on different images.