True ortho-photo generation from high resolution satellite imagery

Abstract

Ortho-photos contain highly valuable data with high potential. They an useful in various applications, such as the creation of image maps and tex ture information in Geographic Information System (GIS). The Z-buffei method has been one of the most popular methods for the true ortho-photc generation. However, it has strict requirements regarding the Digital Surface Model (DSM) cell size. Furthermore, Z-buffer Method have false visibility problmes in narrow vertical structrues. The Z-buffer Method car be modified to avoid this problem using pseudo points along vertical surfaces. However, this method still has problems with certain DSM resolutions. This study implements two technical approaches for true ortho-photc generation u(1) the horizontal position of a point along the search path reaches the nadir point in the object space sing high resolution satellite imagery. The first approach deals with the scan line search method, which is required since each scan line has its own perspective center. The other approach is concerned with occlusion detection, which is required for the creation of true ortho-photos. Final experimental results with real date have demonstrated the feasibility of this proposed true ortho-photo generation methodology.