Papers › Making the Invisible Visible: Action Recognition Through Walls and Occlusions

Making the Invisible Visible: Action Recognition Through Walls and Occlusions

20 Sep 2019ICCV 2019 10arXiv:1909.09300archive 2025-07-28

Tianhong Li, Lijie Fan, Ming-Min Zhao, Yingcheng Liu, Dina Katabi

Understanding people's actions and interactions typically depends on seeing them. Automating the process of action recognition from visual data has been the topic of much research in the computer vision community. But what if it is too dark, or if the person is occluded or behind a wall? In this paper, we introduce a neural network model that can detect human actions through walls and occlusions, and in poor lighting conditions. Our model takes radio frequency (RF) signals as input, generates 3D human skeletons as an intermediate representation, and recognizes actions and interactions of multiple people over time. By translating the input to an intermediate skeleton-based representation, our model can learn from both vision-based and RF-based datasets, and allow the two tasks to help each other. We show that our model achieves comparable accuracy to vision-based action recognition systems in visible scenarios, yet continues to work accurately when people are not visible, hence addressing scenarios that are beyond the limit of today's vision-based action recognition.

PaperPDFConference PDF

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

Code

No code repository is listed for this paper in the archive or in Syntology's graph.

Code Syntology ran Syntology

Not run by Syntology. Nothing on this page verifies that the listed code works.

Tasks

3D Human Pose EstimationAction RecognitionRF-based Pose EstimationSkeleton Based Action Recognition

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
RF-based Pose Estimation RF-MMD RF-Action mAP (@0.1, Through-wall) 86.5 #1 of 1 Archive leaderboard report
RF-based Pose Estimation RF-MMD RF-Action mAP (@0.1, Visible) 90.1 #1 of 1 Archive leaderboard report
Skeleton Based Action Recognition NTU RGB+D RF-Action Accuracy (CS) 86.8 #80 of 135 Archive leaderboard report
Skeleton Based Action Recognition NTU RGB+D RF-Action Accuracy (CV) 91.6 #80 of 135 Archive leaderboard report
Skeleton Based Action Recognition PKU-MMD RF-Action mAP@0.50 (CS) 92.9 #1 of 4 Archive leaderboard report
Skeleton Based Action Recognition PKU-MMD RF-Action mAP@0.50 (CV) 94.4 #1 of 4 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections