The storage and reconstruction of polygon boundaries using circles
Moore, Antoni; Mason, Chris; Whigham, Peter A; Thompson-Fawcett, Michelle
This paper investigates the accuracy of using circles to store polygon boundaries. Can a series of xy points be accurately replaced by a smaller array of variably-sized circles used in a non space filling sense to approximate to the edge of the polygon? Two measures were used to ascertain this, areal error and visual error. A vector dataset representing the island of Rarotonga was converted from boundary coordinates to circle storage using a Voronoi-based medial axis approach. Three parameters were altered to derive as many as 150 circle-based realisations – minimum allowed circle radius, degree of overlap allowed between circles and Douglas-Peucker algorithm threshold (the latter algorithm of line reduction was used to extract “important” points from the polygon and add them to the circle list as “zero-radius circles”). This presentation presents and analyses the areal error and visual error results for all realisations.
Conference: 15th Annual Colloquium of the Spatial Information Research Centre (SIRC 2003: Land, Place and Space), Dunedin, New Zealand
Keywords: areal error; visual error; cartographic generalisation
Research Type: Conference or Workshop Item (Paper)