The simplest technique is to represent linear structures by their geometric parameters; for example, a line segment may be represented by 4 parameters, e.g.

• Line = { } or
• Line = { (, length, orientation) }
• Line = { (, , ( or ), ( or )) }

where and define the end coordinates of the line and the centre of the line. An arc requires 6 parameters, of which there are several choices, e.g.

• Arc = { }

A disadvantage of this method is the requirement for a regular geometric structure composed of lines, arcs, parabolas etc., although piecewise approximations (see the next section: Chain Codes) may be possible.

[ Representation of two-dimensional boundaries | Chain Codes ]

Comments to: Sarah Price at ICBL.
(Last update: 22th April, 1996)