Hierarchical approach to reconstruct surfaces by using iteratively rectified imagery

A new approach to reconstruct the three-dimensional surface of the object space from digital images is described. All the object points obtained by an automatic orientation procedure lead to a first approximation of the surface. Edges are computed for one image and matched to the other image by grey level correlation or least-squares matching through the scale space. To every discrete step in the scale space there exists the digital stereopair (image pyramid), the corresponding surface (digital elevation model DEM) and the warped images. The warped images in this discrete scale space representation correspond to digital orthophotos obtained from the DEMs that result from matching the image pyramid. We propose to use the warped images on every successive level in the image pyramid in order to reduce the foreshortening problems associated with any area-based matching method. The paper describes the method and some experimental results are reported.