Enhancing Textured Digital Elevation Models Using Photographs

We present a method for enhancing the visual quality of existing digital elevation models textured with orthophotos, using a sparse set of unordered, high resolution photographs. After an initial manual selection of correspondence points, we automatically register the input photographs to the given terrain data set using robust imagebased modeling techniques. To combine the geo-registered images on the terrain surface, we propose a compositing algorithm that ensures smooth transitions between the images while at the same time preserving the fine details. The resulting textures are inserted into the quadtree representation of a terrain rendering engine to allow an efficient realtime visualization. We demonstrate our method on an HRSC terrain data set and a collection of high resolution photos of Turtmann valley in Switzerland.