CF-CAM: Gradient Perturbation Mitigation and Feature Stabilization for Reliable Interpretability

As deep learning continues to advance, the opacity of neural network decision-making remains a critical challenge, limiting trust and applicability in high-stakes domains. Class Activation Mapping (CAM) techniques have emerged as a key approach to visualizing model decisions, yet existing methods face inherent trade-offs. Gradient-based CAM variants suffer from sensitivity to gradient perturbations, leading to unstable and unreliable explanations. Conversely, gradient-free approaches mitigate gradient instability but incur significant computational overhead and inference latency. To address these limitations, we propose Cluster Filter Class Activation Map (CF-CAM), a novel framework that reintroduces gradient-based weighting while enhancing robustness against gradient noise. CF-CAM employs a hierarchical importance weighting strategy to balance discriminative feature preservation and noise elimination. A density-aware channel clustering via Density-Based Spatial Clustering of Applications with Noise (DBSCAN) groups semantically relevant feature channels and discard noise-prone activations. Additionally, cluster-conditioned gradient filtering leverages bilateral filters to refine gradient signals, preserving edge-aware localization while suppressing noise impact. Experiment results demonstrate that CF-CAM achieves superior interpretability performance while maintaining resilience to gradient perturbations, outperforming state-of-the-art CAM methods in faithfulness and robustness. By effectively mitigating gradient instability without excessive computational cost, CF-CAM provides a reliable solution for enhancing the interpretability of deep neural networks in critical applications such as medical diagnosis and autonomous driving.