The Immediate Mode Rendering Model

The AWT imaging model wasn't sufficient for any kind of serious image processing because it didn't provide a mechanism for a persistent memory store of pixel data. In other words, there was no convenient way to get to the pixel data. Note that although it is possible to access data through the grabPixels() method, operations on this data were quite limited. Easier access to the pixel data was added in Java 2D with the introduction of the immediate mode rendering model. The immediate mode rendering model is based on the concept of a buffered image. The class BufferedImage represents an area of memory containing pixel data. The ability to use an accessible data buffer enables custom filtering operations such as blurring and sharpening as well as color operations such as color correction and color banding. Buffered imaging is covered in substantially more detail in Chapter 4.

Because a BufferedImage is a Java image in every sense of the word, it must have the three components listed in the preceding Java image description. That is, it must have a DataBuffer, a SampleModel, and a ColorModel.