ERROR DETECTION IN DIGITAL ELEVATION MODEL USING A CAMERA IMAGE

A digital elevation model (DEM) contains the elevation of terrain, which is widely used in the geographic information system (GIS). However, a DEM may not be accurate due to the measurement inaccuracy and the change of topography with time. In this paper, we propose a feature based algorithm for detecting DEM elevation errors using a camera image. In the algorithm, we first extract ridges in a depth map obtained from a DEM. We then extract ridges in the corresponding camera image, and determine the elevation error in the DEM, if any, by comparing the corresponding points of ridges between the depth map and camera image. To robustly extract a ridge in the camera image, we adopt a mask that is obtained using the ridge information in the depth map, and apply dynamic programming within the mask. Experimental results show that the proposed algorithm can reliably determine elevation errors in the DEM.