Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

443Applications of Augmented Reality for the Automotive Industry

frame, and an arbitrary scale factor when a single camera is used. However, this last

drawback can be partially resolved by bootstrapping the 3D model of the scene with

the help of a model-based tracking approach. While the model-based solution is used

to estimate the pose of the rst keyframe, an initial reconstruction of the scene is

achieved by back-projecting the 2D image features onto the CAD model of the target

object (Bleser etal. 2006). If this initial reconstruction process provides a coordinate

frame and a scale factor to the VSLAM localization, their accuracy remains limited

since the reconstruction is achieved from a single point of view.

In the following, we wil