Visual Localization & SLAM

Published research

Reliable spatial perception starts with establishing correspondences across images and connecting observations to a 3D map. We develop feature-matching and visual-localization methods for scenes affected by changes in illumination, viewpoint, weather, and appearance.

TopicFM and TopicFM+ use latent topic representations to guide matching between related image regions. Our semi-dense localization method extends 2D-3D correspondences beyond predefined map points by inferring scene coordinates from geometric and visual cues. These methods provide components for camera pose estimation and image-based mapping.

  • Context-aware matching: use shared scene context to distinguish image features in visually difficult regions.
  • Semi-dense correspondences: infer additional scene coordinates to make better use of image matches.
  • Map-based localization: estimate camera pose when reference observations or 3D map points are sparse or noisy.
Image-matching examples, camera-localization comparisons, and reconstructed scenes with camera trajectories
Examples of image correspondences, camera-localization comparisons, and reconstructed environments with estimated camera trajectories.

Multi-View Stereo & Neural Rendering

Published research

We reconstruct scene geometry from overlapping images and develop scene representations that support novel-view rendering. Our work addresses both depth-estimation quality and the practical limits of updating a model as new images arrive.

Curvature-guided feature extraction adapts matching support to local surface structure, while prior-depth-based multi-view stereo (MVS) reuses sequential depth estimates to improve online reconstruction. For 3D Gaussian Splatting (3DGS), adaptive view selection adds informative non-keyframes to refine incomplete regions. PR-IQA evaluates diffusion-generated views against reference observations and uses quality estimates to filter unreliable supervision.

  • Depth estimation: combine geometry-aware image features with depth information accumulated over time.
  • Online Gaussian mapping: select useful observations to improve scene coverage under limited update time.
  • Quality-aware synthesis: identify reliable regions in generated views before using them to train a 3D representation.
Depth-map comparisons, a historical MVS leaderboard, Gaussian scene renderings, and urban 3D reconstructions
Depth estimation, neural rendering, and large-scale reconstruction examples. The included leaderboard is a historical benchmark snapshot.
Related reconstruction projects

Active 3D Scanning

Published research; latest work accepted to IROS 2026

A robot's viewpoint determines which surfaces can be reconstructed. We combine online 3D modeling with view-path planning so an aerial robot can respond to missing or weakly reconstructed regions during data collection.

Our methods analyze the evolving surface model, identify inspection targets, and plan observations that improve coverage and geometric quality. Recent work combines an initial coverage pass with targeted return re-scanning within a limited flight budget. The objective is to direct sensing effort toward regions where additional observations are most useful.

  • Surface-quality assessment: locate incomplete or uncertain surfaces as the model is reconstructed.
  • Coverage and inspection: combine global coverage paths with local observations of difficult regions.
  • Budget-aware re-scanning: choose return observations while accounting for the available flight budget.
Online reconstruction and inspection-planning pipeline with initial coverage and budgeted return re-scanning paths
Online reconstruction and inspection planning, alongside the initial coverage and targeted return paths in the work accepted to IROS 2026.

3D Scene Graphs

Ongoing research

A geometric map describes shape, but robot tasks also require information about objects and their relationships. We investigate 3D scene graphs that connect object instances, spatial relations, and visual evidence in a form that can support language-guided planning.

Our current approach combines observations from selected views with contextual spatial constraints to examine uncertain object candidates. We aim to reduce false detections and construct more compact object representations, while keeping task plans grounded in evidence from the environment.

  • Object-level mapping: represent object instances and their spatial relationships in 3D.
  • Candidate verification: compare visual evidence with spatial context when observations are ambiguous.
  • Task grounding: connect language-guided plans to the objects represented in the scene.
Illustration comparing dense object candidates with a compact scene graph and contextual object verification
Illustration of object-candidate filtering and contextual verification for a more compact 3D scene graph.
Language-guided robot planning

Multi-Object Tracking

Ongoing research

Robots operating around people need to distinguish moving objects and maintain their identities over time. We investigate multi-object tracking in video sequences, focusing on the difficulty of associating observations when objects overlap, disappear from view, or change appearance.

The goal is to provide temporally consistent information about dynamic scenes that can complement localization and mapping. Our research examines how detection and association can preserve useful object tracks in crowded environments and through intermittent observations.

  • Association across frames: connect detections that correspond to the same object.
  • Identity consistency: study how to retain tracks through occlusion and appearance changes.
  • Dynamic-scene perception: explore how object tracks can complement a robot's spatial map.
Video frames with pedestrian boxes and identity labels in outdoor, crowded, and performance scenes
Example tracking scenarios with object boxes and identity labels across successive video frames.
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