Occlusion-compensated true orthorectification for high-resolution satellite images

This paper describes a method to generate true ortho-images from high-resolution satellite images. Multi-view images are used to compensate for hidden areas. This work includes three steps: (1) the generation of traditional ortho-images using a terrain model, (2) the relief correction for buildings, and (3) the detection of, and compensation for, hidden areas. A rational function model (RFM) is used to determine the geometric correspondence between the image space and the object space. In the generation of traditional ortho-images, RFM parameters and a digital terrain model (DTM) are employed to rectify tilt displacements and relief displacements for the terrain. Then, using a digital building model (DBM), relief displacements for buildings are computed. The purpose of the detection of hidden areas is to avoid double mapping. Considering the satellite's small field of view, an efficient method for the detection of hidden areas and building rectification is proposed. The test area covers the city of Hsinchu in northern Taiwan. The test images are obtained from the QuickBird satellite.