We may find different floor numbers from the multiple facades of one building. It is possible that a building has different floor counts on a sloping terrain. Since the Bald Earth as well as the slope of a building footprint is known, this must enter into the floor count. We have redundant information also from overlapping images all showing one and the same facade. Figure 15 illustrates four results for one single facade imaged four times. The window locations are defined to within ±3 pixel in both horizontal as well as vertical directions, converting to a value of ±0.3 m vertically and ±0.3 m horizontally. In this example all 28 windows of the facade were found in all four aerial images.