vector graphics

vector graphics, mathematically based computer image format.

Vector graphics, composed of lines defined by mathematical formulas, were first used in computer displays in the 1960s and ’70s. The displays were essentially modified oscilloscopes, and vector graphics were used because the memory that would be needed for displaying raster graphics, or bit-mapped graphics, was too expensive. Vector graphics were also used in early arcade games such as Asteroids. By the 1980s, raster graphics, which use dots called pixels to create an image, had all but replaced vector graphic displays.

Vector graphics made a comeback, however. Graphic designers use vector graphics to create graphics that need to be scaled. The nature of vector graphics, where each line, curve, shape, and colour is mathematically defined, lends itself to creating images that can be scaled down for a business card or up for a billboard. The popularity of vector graphics led the World Wide Web Consortium (W3C) to create a graphics language called scalable vector graphics (SVG). SVG is a royalty-free language that contains vector shapes and text and can contain embedded raster graphics. One common application for vector graphics in general, and SVG specifically, is in geographic information systems (GIS). SVG is used in GIS applications to produce maps that are scalable and interactive.