19 research outputs found
TrackletMapper: Ground Surface Segmentation and Mapping from Traffic Participant Trajectories
Robustly classifying ground infrastructure such as roads and street crossings
is an essential task for mobile robots operating alongside pedestrians. While
many semantic segmentation datasets are available for autonomous vehicles,
models trained on such datasets exhibit a large domain gap when deployed on
robots operating in pedestrian spaces. Manually annotating images recorded from
pedestrian viewpoints is both expensive and time-consuming. To overcome this
challenge, we propose TrackletMapper, a framework for annotating ground surface
types such as sidewalks, roads, and street crossings from object tracklets
without requiring human-annotated data. To this end, we project the robot
ego-trajectory and the paths of other traffic participants into the ego-view
camera images, creating sparse semantic annotations for multiple types of
ground surfaces from which a ground segmentation model can be trained. We
further show that the model can be self-distilled for additional performance
benefits by aggregating a ground surface map and projecting it into the camera
images, creating a denser set of training annotations compared to the sparse
tracklet annotations. We qualitatively and quantitatively attest our findings
on a novel large-scale dataset for mobile robots operating in pedestrian areas.
Code and dataset will be made available at
http://trackletmapper.cs.uni-freiburg.de.Comment: 19 pages, 14 figures, CoRL 2022 v
Survey on video anomaly detection in dynamic scenes with moving cameras
The increasing popularity of compact and inexpensive cameras, e.g.~dash
cameras, body cameras, and cameras equipped on robots, has sparked a growing
interest in detecting anomalies within dynamic scenes recorded by moving
cameras. However, existing reviews primarily concentrate on Video Anomaly
Detection (VAD) methods assuming static cameras. The VAD literature with moving
cameras remains fragmented, lacking comprehensive reviews to date. To address
this gap, we endeavor to present the first comprehensive survey on Moving
Camera Video Anomaly Detection (MC-VAD). We delve into the research papers
related to MC-VAD, critically assessing their limitations and highlighting
associated challenges. Our exploration encompasses three application domains:
security, urban transportation, and marine environments, which in turn cover
six specific tasks. We compile an extensive list of 25 publicly-available
datasets spanning four distinct environments: underwater, water surface,
ground, and aerial. We summarize the types of anomalies these datasets
correspond to or contain, and present five main categories of approaches for
detecting such anomalies. Lastly, we identify future research directions and
discuss novel contributions that could advance the field of MC-VAD. With this
survey, we aim to offer a valuable reference for researchers and practitioners
striving to develop and advance state-of-the-art MC-VAD methods.Comment: Under revie