SVG Essentials, 2nd Edition

Chapter 1. Getting Started

SVG, which stands for Scalable Vector Graphics, is an application of XML that makes it possible to represent graphic information in a compact, portable form. Interest in SVG is growing rapidly. Most modern web browsers can display SVG graphics, and most vector drawing software programs can export SVG graphics. This chapter begins with a description of the two major systems of computer graphics, and describes where SVG fits into the graphics world. The chapter concludes with a brief example that uses many of the concepts that you will explore in detail in the following chapters.

Graphics Systems

The two major systems for representing graphic information on computers are raster and vector graphics.

Raster Graphics

In raster graphics, an image is represented as a rectangular array of picture elements or pixels (see Figure 1-1). Each pixel is represented either by its RGB color values or as an index into a list of colors. This series of pixels, also called a bitmap, is often stored in a compressed format. Because most modern display devices are also raster devices, displaying an image requires a viewer program to do little more than uncompress the bitmap and transfer it to the screen.

Figure 1-1. Raster graphic rectangle

Vector Graphics

In a vector graphics system, an image is described as a series of geometric shapes (see Figure 1-2). Rather than receiving a finished ...