was then assessed using an error matrix. The accuracies computed from the error matrix include the user accuracy , producer accuracy , overall accuracy and Kappa coefficient . At the same time, both the producer’s and user’s average accuracies are also calculated to represent the average accuracies of each individual class. In the experiment, a total of 35 buildings that exist in both the pre- and post-seismic areas were used as reference data, and the status of these buildings were observed in situ. Error matrices were produced employing two methods. The first examines the conditions of the difference DEM pixels in pre- and post-seismic areas, and the second examines the conditions of the building objects by regarding each building as an object.