Fourier Decomposition

Search documents
ICML 2025 Spotlight | 用傅里叶分解探讨图像对抗扰动,代码已开源
机器之心· 2025-05-18 04:25
Core Viewpoint - The article discusses a novel approach to adversarial purification in computer vision, focusing on the frequency domain to effectively separate adversarial perturbations from clean images while preserving semantic information [5][21]. Research Background - Adversarial samples pose significant challenges to the safety and robustness of models in computer vision, necessitating effective adversarial purification techniques to restore original clean images [5]. - Existing adversarial purification methods are categorized into training-based and diffusion model-based approaches, with the latter offering stronger generalization capabilities without requiring extensive training data [5][6]. Motivation and Theoretical Analysis - The key to successful adversarial purification lies in eliminating adversarial perturbations while retaining the semantic information of the original image [9]. - Current strategies that add noise to mask adversarial perturbations often excessively damage the semantic content of the original image [9]. - The study employs Fourier decomposition to analyze the distribution characteristics of adversarial perturbations, revealing that they predominantly affect high-frequency components, while low-frequency components are more robust [9][12]. Methodology - A filter is constructed to retain low-frequency amplitude spectrum components, which are less affected by adversarial perturbations, while allowing for the replacement of these components with those from the original clean image [14][15]. - The phase spectrum is also addressed, as it is influenced by adversarial perturbations across all frequency components; thus, a projection method is used to maintain the integrity of the phase information [16][17]. Experimental Results - The proposed method demonstrates improved performance in both standard and robust accuracy metrics compared to state-of-the-art (SOTA) methods on datasets such as CIFAR10 and ImageNet [18][19]. - Visualizations indicate that the purified images closely resemble the original clean images, confirming the effectiveness of the proposed approach [20]. Conclusion - While significant progress has been made in preserving semantic information and removing adversarial perturbations, further exploration into more effective image decomposition methods and deeper theoretical explanations remains a future research direction [21].