Sara Ghazanfari

I am currently a Ph.D. candidate at New York University in the EnSuRe Research Group. I'm pleased to be co-advised by Siddharth Garg and Farshad Khorrami. My primary research is focused on the intersection of trustworthy machine learning and computer vision with the goal of improving the robustness of vision systems by providing robust representations.

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News
  • Jan-2024: One paper accepted to ICLR 2024.
  • June-2023: One paper accepted to ICML Workshop 2023.
Research
LipSim: A Provably Robust Perceptual Similarity Metric
S. Ghazanfari, A. Araujo, P. Krishnamurthy, F. Khorrami and S. Garg
ICLR, 2024
PDF / arXiv / code

In this work, we demonstrate the vulnerability of the SOTA perceptual similarity metric based on an ensemble of ViT-based feature extractors to adversarial attacks. We then propose a framework to train a robust perceptual similarity metric called LipSim (Lipschitz Similarity Metric) with provable guarantees by leveraging 1-Lipschitz neural networks as backbone and knowledge distillation approach to distill the knowledge of the SOTA models. Finally, a comprehensive set of experiments shows the performance of LipSim in terms of natural and certified scores and on the image retrieval application.

R-LPIPS: An Adversarially Robust Perceptual Similarity Metric
S. Ghazanfari, S. Garg, P. Krishnamurthy, F. Khorrami and A. Araujo
ICML Workshop, 2023
PDF / arXiv / code

In this work, we show that the LPIPS metric is sensitive to adversarial perturbation and propose the use of Adversarial Training to build a new Robust Learned Perceptual Image Patch Similarity (R-LPIPS) that leverages adversarially trained deep features. Based on an adversarial evaluation, we demonstrate the robustness of R-LPIPS to adversarial examples compared to the LPIPS metric. Finally, we showed that the perceptual defense achieved over LPIPS metrics could easily be broken by stronger attacks developed based on R-LPIPS.