  We present COMO, a real-time monocular mapping and odometry system that
encodes dense geometry via a compact set of 3D anchor points. Decoding anchor
point projections into dense geometry via per-keyframe depth covariance
functions guarantees that depth maps are joined together at visible anchor
points. The representation enables joint optimization of camera poses and dense
geometry, intrinsic 3D consistency, and efficient second-order inference. To
maintain a compact yet expressive map, we introduce a frontend that leverages
the covariance function for tracking and initializing potentially visually
indistinct 3D points across frames. Altogether, we introduce a real-time system
capable of estimating accurate poses and consistent geometry.
