Augmented reality (AR) systems pose unique privacy risks due to their continuous capture of visual data. Existing AR privacy frameworks lack semantic understanding of visual content, limiting their effectiveness in detecting context-dependent privacy risks. We propose PrivAR, which leverages vision language models (VLMs) with chain-of-thought prompting for contextual privacy risk detection in AR environments. PrivAR uses visual scene cues to infer potential sensitive information types, such as identifying password notes in office environments through contextual reasoning. PrivAR detects and obfuscates textual content, preventing exposure of sensitive information while preserving contextual cues necessary for VLM inference. Additionally, we investigate contextually-informed warning interfaces to enhance user privacy awareness. Experiments on a real-world AR dataset show that PrivAR achieves superior accuracy (81.48%) and F1-score (84.62%) compared to baselines, while reducing privacy leakage rate to 17.58%. User studies evaluating contextually-informed warning interfaces provide insights into effective privacy-aware AR design.
Figures & tables
Figure 1: System architecture of PrivAR.
Figure 2: Different warning modes when a risk of privacy leakage is identified: (a) center-screen warning, (b) top-screen warning, and (c) region overlay warning.
Detection method
Acc.(%) ↑
Prec.(%) ↑
Rec.(%) ↑
F1(%) ↑
Rule-based
39.58
44.00
8.63
14.43
Sensitive object recognition
55.79
50.00
83.77
62.62
Scene captioning-based
67.36
82.02
57.25
67.44
PrivAR (ours)
81.48
83.02
86.27
84.62
Table 1: Privacy risk detection performance of PrivAR and baseline approaches.
VLM
Acc.(%) ↑
Prec.(%) ↑
Rec.(%) ↑
F1(%) ↑
GPT-4o mini
81.48
83.02
86.27
84.62
GPT-4o
82.87
84.41
87.06
85.71
LLaMA-4-Mav.
78.47
81.15
82.75
81.94
Table 2: Privacy risk detection performance of PrivAR with different VLMs.
Protection method
CER (%) ↑
PLR (%) ↓
Oracle-guided obfuscation
91.11±14.57
2.29
PriAR w/o obfuscation
74.30±26.70
82.18
PrivAR (ours)
95.71±6.88
17.58
Table 3: Privacy protection effectiveness of 3 methods.