[image] c.valenti - 2015

Unlocking the Mysteries of the Bounding Box

Persistent URL for citation: http://purl.oclc.org/coordinates/a2.htm

Douglas R. Caldwell

Douglas R. Caldwell (e-mail: Douglas.R.Caldwell@erdc.usace.army.mil) is employed as a cartographer and geospatial analyst at the US Army Engineer Research & Development Center, Topographic Engineering Center, Research Division, Information Generation and Management Branch, 7701 Telegraph Road, Alexandria, VA 22315. 

Date of Publication: 08/29/05

Abstract

Few geospatial data representations are more basic than the bounding box; a rectangle surrounding a geographic feature or dataset. Bounding boxes are a key component of geospatial metadata and lie at the heart of many computational geometry algorithms as well as spatial indexing systems. Despite their ubiquity and common use, bounding boxes are more complicated than they first appear. The phrase that ‘spatial is special’ applies to this humble representation as well as to more sophisticated geospatial representations. This paper explores the nuances of correctly understanding, using, and interpreting bounding boxes.

Keywords: Bounding box, Minimum Bounding Rectangle (MBR), metadata, map projection, geographic information systems, GIS

The bounding box is a fundamental component of numerous computational geometry algorithms, indexing schemes such as R-trees, and metadata. As a surrogate for a feature, it provides exact information on the extent or limits of the feature and approximates the coverage. Despite its ubiquity and simplicity, the bounding box remains a subtle and nuanced entity, showing once again that "spatial is special."

http://www.stonybrook.edu/libmap/coordinates/seriesa/no2/a2.htm