Online environment mapping

A non-transitory computer-readable storage medium storing executable computer program code for generating an environment map of an input video sequence, the computer program code comprising instructions for:

• identifying a plurality of keyframes of the input video sequence and adding the identified keyframes into an initial environment map, the keyframes being identified based on video features associated with a plurality of video frames of the input video sequence, and the initial environment map being represented by a keyframe pose graph;
• enforcing local metric properties of a group of identified keyframes of the initial environment map;
• optimizing the initial environment map based on global metric properties of the identified keyframes, wherein optimizing the initial environment map comprises:
• clustering the identified keyframes into a plurality of disjoint sets of keyframes based on geodesic distance information of the keyframe pose graph, a disjoint set of keyframes representing a segment of keyframes;
• for each segment of keyframes, enforcing local metric properties of the keyframes in the segment;
• applying global segment optimization to the segments of keyframes, comprising:
• embedding the segments of keyframes and landmarks associated with the keyframes of the segments into a metric space;
• and
• updating projected three-dimensional coordinates of the landmarks to the associated keyframes based on the metric constraints of the landmarks and keyframes;
• and
• generating an output environment map based on the optimization.

A computer system for generating an environment map of an input video sequence, the system comprising:

• a location recognition module for identifying a plurality of keyframes of the input video sequence and adding the identified keyframes into an initial environment map, the keyframes being identified based on the video features associated with a plurality of video frames of the input video sequence, and the initial environment map being represented by a keyframe pose graph;
• a local adjustment module for enforcing local metric properties of a group of identified keyframes of the initial environment map;
• and
• a global adjustment module for:
• optimizing the initial environment map based on global metric properties of the identified keyframes, wherein optimizing the initial environment map comprises:
• clustering the identified keyframes into a plurality of disjoint sets of keyframes based on geodesic distance information of the keyframe pose graph, a disjoint set of keyframes representing a segment of keyframes;
• for each segment of keyframes, enforcing local metric properties of the keyframes in the segment;
• applying global segment optimization to the segments of keyframes, comprising:
• embedding the segments of keyframes and landmarks associated with the keyframes of the segments into a metric space;
• and
• updating projected three-dimensional coordinates of the landmarks to the associated keyframes based on the metric constraints of the landmarks and keyframes;
• and
• generating an output environment map based on the optimization.