We present a novel method to fuse the power of deep networks with the
computational efficiency of geometric and probabilistic localization
algorithms. In contrast to other methods that completely replace a classical
visual estimator with a deep network, we propose an approach that uses a
convolutional neural network to learn difficult-to-model corrections to the
estimator from ground-truth training data. To this end, we derive a novel loss
function for learning SE(3) corrections based on a matrix Lie groups approach,
with a natural formulation for balancing translation and rotation errors. We
use this loss to train a Deep Pose Correction network (DPC-Net) that predicts
corrections for a particular estimator, sensor and environment. Using the KITTI
odometry dataset, we demonstrate significant improvements to the accuracy of a
computationally-efficient sparse stereo visual odometry pipeline, that render
it as accurate as a modern computationally-intensive dense estimator. Further,
we show how DPC-Net can be used to mitigate the effect of poorly calibrated
lens distortion parameters.Comment: In IEEE Robotics and Automation Letters (RA-L) and presented at the
IEEE International Conference on Robotics and Automation (ICRA'18), Brisbane,
Australia, May 21-25, 201