Painting the Web

Chapter 2. Imagine

Nothing replaces text when it comes to providing information, but how dull our world would be without the imagery that has been a part of publications from the beginning. The very first book ever published, the Gutenberg Bible, contains exquisite illustrations, following a tradition of such ornamentation that extended to cultures all around the world and has lasted to today's new digital medium.

The graphics files we use on the Web have become so ubiquitous that it's difficult to imagine not having them. Computer graphics, though, are relatively new. They originated at MIT when a student named Ivan Sutherland used a light pen to draw objects to a computer in 1960. The type of image he created is known as a vector graphic. It's called this because the image is created through vectors or paths between mathematically derived computer points, and controlled by commands issued via an application of some form. Scalable Vector Graphics (SVG), featured in several chapters throughout this book, is an example of this type of graphic.

Another type of graphic is the bitmap, or raster, graphic. Unlike the vector, raster graphics consist of a set of points or dots, each containing color and other information. The commonly occurring Graphics Interchange Format (GIF), Joint Photographic Experts Group (JPEG), and Portable Network Graphics (PNG) are all examples of this type of graphic.

Incorporating graphics into web pages came about because of one simple HTML element: the IMG element, ...