Java AWT Reference

12

Image Processing

In this chapter:

• ImageObserver
• ColorModel
• ImageProducer
• ImageConsumer
• ImageFilter

The image processing parts of Java are buried within the java.awt.image package. The package consists of three interfaces and eleven classes, two of which are abstract. They are as follows:

• The ImageObserver interface provides the single method necessary to support the asynchronous loading of images. The interface implementers watch the production of an image and can react when certain conditions arise. We briefly touched on ImageObserver when we discussed the Component class (in Chapter 5, Components), because Component implements the interface.
• The ImageConsumer and ImageProducer interfaces provide the means for low level image creation. The ImageProducer provides the source of the pixel data that is used by the ImageConsumer to create an Image.
• The PixelGrabber and ImageFilter classes, along with the AreaAveragingScaleFilter, CropImageFilter, RGBImageFilter, and ReplicateScaleFilter subclasses, provide the tools for working with images. PixelGrabber consumes pixels from an Image into an array. The ImageFilter classes modify an existing image to produce another Image instance. CropImageFilter makes smaller images; RGBImageFilter alters pixel colors, while AreaAveragingScaleFilter and ReplicateScaleFilter scale images up and down using different algorithms. All of these classes implement ImageConsumer because they take pixel data as input.
• MemoryImageSource and FilteredImageSource ...