[Previous] [Next]

Sources of Vector Format Files

The simplest vector formats are those used by spreadsheet applications. These normally contain numerical data meant to be displayed on a 2D grid on an output device. Some non-spreadsheet applications use spreadsheet file formats to store data that can alternately be interpreted as either bitmap or vector data.

Examples of common spreadsheet formats include those associated with the programs Lotus 1-2-3 (.WKS and .WK1), Excel (.XLS), and Quattro Pro. Although these originated on Intel-based PCs, the respective vendors now support multiple platforms. Several spreadsheet formats have been developed explicitly to support portable data interchange between different spreadsheet applications; as a result, these are now also found on multiple platforms. These include Lotus DIF (Data Interchange Format) and Microsoft SYLK (SYmbolic LinK Format).

The majority of vector formats, however, are designed for storing line drawings created by CAD applications. CAD packages are used to create mechanical, electrical, and architectural drawings, electronic layouts and schematics, maps and charts, and artistic drawings. The complexity of information needed to support the needs of a major CAD application is considerably greater than that needed to support a spreadsheet and generally requires a more complicated vector format.

CGM (Computer Graphics Metafile) is an example of a general format designed with data interchange in mind, a format that is defined in a published standard. All elements in a CGM-format file are constructed of simple objects such as lines and polygons, primitives assumed to be available in every rendering application. Very complex objects are broken down into the simplest possible shapes.

Autodesk's AutoCAD DXF (Data eXchange Format) was also designed with vector data interchange in mind but is vendor-controlled and originated as a format supporting a single application. In addition, DXF was specifically tailored for CAD information useful in the construction of mechanical, electrical, and architectural drawings. DXF therefore supports not only common vector elements such as circles and polygons, but also complex objects frequently used in CAD renderings, such as 3D objects, labels, and hatching.

[Previous] [Next]

This page is taken from the Encyclopedia of Graphics File Formats and is licensed by O'Reilly under the Creative Common/Attribution license.