ASTRACT: This paper presents the results of the application of mathematical morphology techniques for a semi-automatic quantification of the number of dwellings in an IDP camp in Sri Lanka. The specific assessment was undertaken based on a WorldView-1 satellite image (0.5m). First, an area opening was used to suppress all bright objects whose area was below a given threshold value. These objects were then revealed by computing the difference between the original and the transformed images, considering at the final stage a given size criterion. In a second step, the extracted structures were counted in a GIS using the centroids of the dwellings and limited visual interpretation.
The assessment for the IDP camp indicates an overall number o f 10,138 tents on the 10th of May, 2009. After the 10th of May 2009, the camp had been abandoned and was destroyed to a la rge extend.