Rapid facilitation of dasymetric-based population interpolation by means of raster pixel maps Mitchel Langford * School of Computing, University of Glamorgan, Pontypridd, Wales, UK Received 30 April 2004; received in revised form 18 July 2005; accepted 18 July 2005 Abstract Areal interpolation between one partitioning of geographical space and another remains an important topic, particular in terms of population counts and related statistics which are often required in order to compute an incidence ratio. Despite numerous recent developments in intelligent areal interpolation methods, and studies that have demonstrated their clear advantage over simple areal weighting, there is little evidence to suggest widespread usage amongst the GIS user com- munity. It is argued that to encourage greater uptake such methods must offer simplicity and con- venience. Areal interpolation based on binary dasymetric mapping is conceptually simple, but examples to date tend to use information extracted from multi-spectral satellite imagery which limits its perceived convenience. This paper examines a simple method to extract equivalent information from a raster pixel map. It is shown to offer comparable areal interpolation performance at con- siderably less cost in terms of both time and complexity. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Interpolation; Dasymetric; Population; Raster 1. Introduction GIS users often manipulate and manage thematic or attribute information either associated with, or directly generated from, a corresponding spatial zone. These zones may be defined by real natural boundaries or by abstract lines in geographical space, with 0198-9715/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.compenvurbsys.2005.07.005 * Tel.: +44 1443 654148; fax: +44 1443 652715. E-mail address: mlangfor@glam.ac.uk Computers, Environment and Urban Systems 31 (2007) 19–32 www.elsevier.com/locate/compenvurbsys