Mapping Ground Video to Aerial Dem ’ S ∗

We present an approach for registering an aerial Digital Elevation Model (DEM) with a color intensity image obtained using a camera mounted on a mobile robot. An approximate measurement of the camera pose is obtained using auxiliary sensors on-board the robot. The DEM is transformed into a depth map in the camera’s coordinate system using this initial pose. The problem is now simplified to the alignment of two images, one containing intensity information, and the other, depth. Region boundaries in the intensity image are matched with discontinuities in the depth map using a robust directed Hausdorff distance. This cost function is minimized with respect to the six parameters defining the camera pose. Due to the highly non-linear nature of cost function with multiple local minima, a stochastic algorithm based on the downhill simplex principle is employed for minimization. Results on real data are presented.