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arXiv · 2503.20184

Spectrum from Defocus: Fast Spectral Imaging with Chromatic Focal Stack

M. Kerem Aydin·Yi-Chun Hung·Jaclyn Pytlarz·Qi Guo·Emma Alexander
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Abstract

Hyperspectral cameras face harsh trade-offs between spatial, spectral, and temporal resolution in inherently low-photon conditions. Computational imaging systems break through these trade-offs with compressive sensing, but have required complex optics and/or extensive compute. We present Spectrum from Defocus (SfD), a chromatic focal sweep method that achieves state-of-the-art hyperspectral imaging with only two off-the-shelf lenses, a grayscale sensor, and less than one second of reconstruction time. By capturing a chromatically-aberrated focal stack that preserves nearly all incident light, and reconstructing it with a fast physics-based iterative algorithm, SfD delivers sharp, accurate hyperspectral images. The combination of photon efficiency, optical simplicity, and physical interpretability makes SfD a promising solution for fast, compact, interpretable hyperspectral imaging.

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M. Kerem Aydin, Yi-Chun Hung, Jaclyn Pytlarz, Qi Guo, Emma Alexander. 2025-03-26. Spectrum from Defocus: Fast Spectral Imaging with Chromatic Focal Stack. https://arxiv.org/abs/2503.20184

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