Chapter 8. Image Basics

In introducing Quartz 2D, and throughout the book up to this point, the fact that Quartz 2D has a resolution independent drawing model has been emphasized. It has also been pointed out that Quartz 2D does not, in general, base its drawing model on the concept of a pixel. However, computer graphics is riddled with resolution dependent graphics that are pixel-based. One of the most popular examples today are the images captured by digital cameras. The digital camera works by capturing light and generating a set of color pixels that closely match what it "sees."

To draw pixel-based graphics, like the images from a digital camera, Core Graphics needs some way to model those graphics. The Quartz 2D API uses the concept of an image for this task.