Vector graphics
A vector graphic is a computer graphic, consisting of graphic primitives such as lines, circles, polygons, or general curves (splines ) is composed. Most are meant by vector graphics representations, let their primitive two-dimensionally describe in the plane. A figure description which is based on three-dimensional primitives is called rather a 3D model or scene.
To save example the image of a circle, a vector graphic requires at least two values: the position of the circle center and the circle diameter. In addition to the shape and position of the primitives and the color, line thickness, various fill patterns, and more, the appearance of determining data may be specified.
- 2.1 graphics applications
- 2.2 page description languages
- 2.3 computer fonts
- 2.4 Computer Games
- 2.5 Internet
- 2.6 Geographic Information Systems
- 2.7 Computer Aided Design
Properties
Illustrations are not based unlike raster graphics on a pixel grid where each pixel is assigned a color value, but on a picture description that the objects from which the image is built, precisely defined. For example, are fully described in a vector graphics on the location of the center point, radius, line thickness and color of a circle; only these parameters are stored. Compared to raster graphics, vector graphics, therefore, can often be saved with a much smaller footprint. One of the key features and advantages over raster graphics is the continuous and lossless scalability.
The term "vector graphics " is related to that until the 1980s, widespread vector screens anzeigten lines ( " vectors" ) with a cathode ray. However Illustrations in the modern sense not only consist of lines, but can also allow other basic shapes. To display on standard today screen monitors vector graphics need to be rasterized.
The creation of vector graphics is the subject of geometric modeling and usually done using a vector graphics program or directly with a markup language. Raster graphics can be converted by the so-called vectorization with certain restrictions in vector graphics; some text recognition programs are based on a Vektorisierungsalgorithmus. By now offer various vector graphics programs to functions that allow you to save vector graphics with gradients and transparency levels, and thus to describe a larger number of images satisfactorily. Even such vector graphics can be, as opposed to raster graphics, convenient and lossless change and transform.
Reproduction cost
Applications
The strength of vector graphics is representations that can be described as a set of graphical primitives satisfying, for example, diagrams or company logos. They are not suitable for scanned images and digital photos that are naturally recognized as raster graphics and can not be converted without loss. Also on the borders encounter vector formats for complex rendered images, which are also calculated directly as raster graphics. However, more and more companies specialize in the vectorization of raster graphics. This is mainly of interest for large-scale image advertising, vehicle or if the vectorization is used as a graphic effect.
Vector graphics can be printed directly on a variety of materials without rasterization using plotters ( chart recorders ) or laser markers.
Graphics applications
For the creation of illustrations, especially for the creation of logos, vector-based drawing programs can be used. The generated 3D modeling tools, 3D scenes can also be regarded as vector graphics.
Page description languages
Vector graphics allow us to describe documents regardless of the resolution of the output device. Using a vector -graphics page description language such as PostScript or resulting from it Portable Document Format (PDF) documents can, in contrast to raster graphics, detail being lost with the highest possible resolution on screens or printed.
Computer fonts
On the major computer systems today are mainly so -called outline fonts using that describe the outline of each character as a vector graphic. Important formats TrueType, PostScript and OpenType.
Computer Games
Early arcade games ran with vector graphics. The first was Spacewar! from the year 1977. known were also Lunar Lander ( Atari, 1979) and Star Wars (Color Vector ). There was also the Vectrex game console.
In these systems, the X / Y deflection of the picture tube used to represent was directly driven, rather than line by line output a graphics memory as at point raster graphics as technical feature. The advantage of this solution is the smooth, free podium appearance of lines; to issue general, particularly complex graphics and texts, but this method is less suitable.
Even on home computers such as the Amiga and Commodore 64, there were a few games that were based on vector graphics, such as Stuntcar Racer or the Elite series. These were, unlike the vector graphics systems, but the vector graphics output directly, but calculated and converted to a raster graphic. Because of this need - for that time - high computing power, these games, however, were generally relatively slow and lacking in detail.
Internet
On the World Wide Web are usually vector graphics in SVG format open or proprietary SWF files ( Macromedia Flash) ago. For 3D scenes is the successor to the Virtual Reality Modeling Language (VRML ) a description of the X3D language. Resurrects the OpenGL based Web Graphics Library ( WebGL ) and based on WebGL JavaScript library Open 3D ( o3d ) by Google.
Geographic Information Systems
In geographic information systems (GIS ), the geometry of parcels and maps in the form of vector data can be stored. Such vector graphics can be comparatively easily link with factual data. A typical GIS vector format is the shapefile.
Computer Aided Design
For technical drawings CAD programs are used. Here the geometry is previously stored as vector data, allowing eg the calculated dimension and creating mass statements and bills of material. A typical CAD vector format is the Drawing Interchange Format (DXF).