Initialization of Model-Based Camera Tracking with Analysis-by-Synthesis

In applications of augmented reality it is an essential task to retrieve the camera pose for correct overlay with virtual content. This can be realized by using a model-based camera tracking approach that fits a given model of the scene to the images captured by the camera. These systems have to be initialized properly for the pose estimation process of continuous tracking. We present a two-step concept for the global initialization of such model-based tracking systems. With a model database and known GPS coordinates as well as compass orientation, it is possible to determine which part of the scene is visible and to obtain a first rough pose. We also introduce a method to refine the initialization pose to overcome GPS inaccuracies. It has been successfully tested in an urban context.