LenslessFace: An End-to-End Optimized Lensless System for Privacy-Preserving Face Verification

TL;DR

LenslessFace introduces an end-to-end optimized lensless system for privacy-preserving face verification, eliminating the need for face reconstruction and enhancing privacy, efficiency, and robustness in lensless imaging applications.

Contribution

It proposes a novel end-to-end approach that directly verifies faces from encoded lensless images, addressing challenges unique to lensless setups and improving over traditional two-stage methods.

Findings

Outperforms two-stage lensless verification methods.

Enhances privacy by avoiding face reconstruction.

Demonstrates robustness in real and simulated environments.

Abstract

Lensless cameras, innovatively replacing traditional lenses for ultra-thin, flat optics, encode light directly onto sensors, producing images that are not immediately recognizable. This compact, lightweight, and cost-effective imaging solution offers inherent privacy advantages, making it attractive for privacy-sensitive applications like face verification. Typical lensless face verification adopts a two-stage process of reconstruction followed by verification, incurring privacy risks from reconstructed faces and high computational costs. This paper presents an end-to-end optimization approach for privacy-preserving face verification directly on encoded lensless captures, ensuring that the entire software pipeline remains encoded with no visible faces as intermediate results. To achieve this, we propose several techniques to address unique challenges from the lensless setup which precludes traditional face detection and alignment. Specifically, we propose a face center alignment scheme, an augmentation curriculum to build robustness against variations, and a knowledge distillation method to smooth optimization and enhance performance. Evaluations under both simulation and real environment demonstrate our method outperforms two-stage lensless verification while enhancing privacy and efficiency. Project website: \url{lenslessface.github.io}.