Automatic Stem Mapping in Three Dimensions by Template Matching from Aerial Photographs
Abstract:Recent developments in remote sensing have shown promising results for the detection and species classification of individual trees from high-resolution imagery of forests in leaf-on condition. Existing image-analysis algorithms produce a two-dimensional stem map in the observed imagery. This paper develops a new algorithm that generalizes existing template-matching algorithms to produce a stem map in the three dimensions of a forest in leaf-off condition. A self-contained algorithm to produce artificial template images is introduced. The image-analysis algorithm was applied to oak (Quercus robur L.) grown under standard silvicultural treatment in Denmark. One analysis gave detection rates in the range 85-98% and root mean squared errors on the stem base coordinates below 8.1, 7.6 and 20.5 cm in the x-, y- and z-directions, respectively. It is concluded that it is indeed feasible to produce a quite accurate three-dimensional stem map.
Document Type: Research Article
Publication date: August 1, 2002