Table 4 shows the error matrix of the detection of the collapsed buildings in terms of pixels based on the difference between the pre-seismic DEM created from the topographical map and the post-seismic DEM created from the IKONOS stereo images as shown in Fig. 11a. Table 5 shows the error matrix based on the difference between the pre- and post-seismic DEMs created from both IKONOS stereo image pairs as shown in Fig. 11b. In both difference DEMs, the spatial resolution is 1m, which is approximately the same as that of the IKONOS images used in the experiment. From the results presented in Table 4 and Table 5, we see that (1) the accuracies of detecting the collapsed buildings in terms of pixels based on the two scenarios of the difference DEMs are rather consistent and the overall accuracy obtained is better than 94%. (2) However, in both difference DEMs, the user’s and producer’s accuracies of detecting the collapsed buildings are lower than those of detecting the buildings that have not collapsed. The reason for this is that there are far more pixels of buildings that have not collapsed than pixels of collapsed buildings.