A vector background is a type of image used as a website's background or as a computer's desktop wallpaper. Rather than the dots or pixels that make up raster images, vector images consist of lines and geometrical shapes, and mathematical equations are used to create the image. Each shape in the image is considered an object that can be easily altered to have a different color or size. To create or alter a vector background, one must use one of the special image editing applications that are available for multiple platforms. Vector backgrounds have both advantages and disadvantages over raster images and are not the best format for all types of images.
Compared to a vector background image that uses mathematical formulas along with lines, curves and shapes, a raster image uses square pixels that become less clear when the image is enlarged in any way. Objects in vector images have two elements that determine how the image appears. The length of each line is the magnitude, and the direction in which the line is positioned determines the orientation.
Vector background images have an advantage over raster graphics in that they can be enlarged without losing image quality. Although raster graphics become distorted and greatly lose quality when enlarged, vector images maintain their look and are much more flexible with resolution. Another advantage is that vector backgrounds have a smaller file size than many other image formats. This makes them well suited for website backgrounds, because they load better for users with slower Internet connections.
Some disadvantages to vector graphics are that they're not the best choice for some types of images and they can take longer to create. While they're suited for illustrated backgrounds that contain complex shapes, they are not useful for photographic images. Vector graphics also don't support some advanced image editing techniques, including lighting effects, complex color changes and blurring. A special image editing application is required to edit vector images, so they are not as universal as raster images and may display differently across different programs.
Vector images are commonly used for maps, architectural designs and various other types of two-dimensional (2D) and three-dimensional (3D) images. Raster images, on the other hand, include pictures taken from cameras, imported from scanners or made in many traditional image editing programs. In addition to vector backgrounds, vector images are often used for company logos, because they can be resized for use on many types of signs, banners and promotional materials.