  The growing popularity of autonomous systems creates a need for reliable and
efficient metric pose retrieval algorithms. Currently used approaches tend to
rely on nearest neighbor search of binary descriptors to perform the 2D-3D
matching and guarantee realtime capabilities on mobile platforms. These methods
struggle, however, with the growing size of the map, changes in viewpoint or
appearance, and visual aliasing present in the environment. The rigidly defined
descriptor patterns only capture a limited neighborhood of the keypoint and
completely ignore the overall visual context.
  We propose LandmarkBoost - an approach that, in contrast to the conventional
2D-3D matching methods, casts the search problem as a landmark classification
task. We use a boosted classifier to classify landmark observations and
directly obtain correspondences as classifier scores. We also introduce a
formulation of visual context that is flexible, efficient to compute, and can
capture relationships in the entire image plane. The original binary
descriptors are augmented with contextual information and informative features
are selected by the boosting framework. Through detailed experiments, we
evaluate the retrieval quality and performance of LandmarkBoost, demonstrating
that it outperforms common state-of-the-art descriptor matching methods.
