Images - Java

CHAPTER 27

Images

This chapter examines the Image class and the java.awt.image package. Together, they provide support for imaging (the display and manipulation of graphical images). An image is simply a rectangular graphical object. Images are a key component of web design. In fact, the inclusion of the <img> tag in the Mosaic browser at NCSA (National Center for Supercomputer Applications) is what caused the Web to begin to grow explosively in 1993. This tag was used to include an image inline with the flow of hypertext. Java expands upon this basic concept, allowing images to be managed under program control. Because of its importance, Java provides extensive support for imaging.

Images are objects of the Image class, which is part of the java.awt package. Images are manipulated using the classes found in the java.awt.image package. There are a large number of imaging classes and interfaces defined by java.awt.image, and it is not possible to examine them all. Instead, we will focus on those that form the foundation of imaging. Here are the java.awt.image classes discussed in this chapter:

CropImageFilter

FilteredImageSource

ImageFilter

MemoryImageSource

PixelGrabber

RGBImageFilter

These are the interfaces that we will use:

ImageConsumer

ImageObserver

ImageProducer

Also examined is the MediaTracker class, which is part of java.awt.