Scale-Awareness of Light Field Camera based Visual Odometry

We propose a novel direct visual odometry algorithm for micro-lens-array-based light field cameras. The algorithm calculates a detailed, semi-dense 3D point cloud of its environment. This is achieved by establishing probabilistic depth hypotheses based on stereo observations between the micro images of different recordings. Tracking is performed in a coarse-to-fine process, working directly on the recorded raw images. The tracking accounts for changing lighting conditions and utilizes a linear motion model to be more robust. A novel scale optimization framework is proposed. It estimates the scene scale, on the basis of keyframes, and optimizes the scale of the entire trajectory by filtering over multiple estimates. The method is tested based on a versatile dataset consisting of challenging indoor and outdoor sequences and is compared to state-of-the-art monocular and stereo approaches. The algorithm shows the ability to recover the absolute scale of the scene and significantly outperforms state-of-the-art monocular algorithms with respect to scale drifts.