Enhancing object detection robustness through adversarial noise filtering with luma non-local means
摘要
Adversarial attacks pose a significant threat to object detectors reliant on Deep Neural Networks (DNNs), often inducing erroneous predictions. Given the scarcity of effective adversarial defense methods for object detection, this paper proposes an innovative defense approach based on adversarial noise filtering using Luma Non-Local Means (LNLM). LNLM leverages the brightness channel of adversarial sample images to guide the color channel processing, effectively removing adversarial noise and restoring samples to their original manifold space. This method is applied during the preprocessing phase and does not require prior knowledge of adversarial attacks or modifications to the object detection model's internal architecture. Comprehensive experiments on four object detectors (Faster R-CNN, SSD, YOLOv3, and YOLOv5) against eight adversarial attacks demonstrate LNLM's effectiveness, with defense success rates exceeding 60% for Faster R-CNN and reaching up to 90.1% for YOLOv3 against specific attacks. LNLM exhibits minimal interference with normal sample detection outcomes and is readily migratable across different object detectors. Furthermore, integrating Grad-CAM provides insights into the nature of adversarial attacks and the effectiveness of the LNLM defense mechanism.