Compact Low-Cost Hyperspectral Imaging
via Angular-to-Spectral Diversity Conversion

ECCV 2026
Kazuma Fujiwara 1, Takuya Funatomi 1,2, Kazuya Kitano 1, Yuki Fujimura 1, Yasuhiro Mukaigawa 1
1Nara Institute of Science and Technology     2Kyoto University

Abstract

Snapshot hyperspectral imaging avoids sequential scanning, but systems that jointly achieve stable reconstruction, low cost, and compact optics remain limited. We present a snapshot hyperspectral imaging system based on angular-to-spectral diversity conversion. A tapered kaleidoscope creates replicated views with distinct incidence directions, and a directly attached birefringent filter converts them into view-channel-dependent spectral transmittances, yielding complementary measurements that better condition the inverse problem for more stable single-shot spectral reconstruction. The system preserves a simple pixel-wise linear model for fast non-learning-based reconstruction and uses only off-the-shelf components without relay optics or cascaded modules.

Key Idea

A tapered kaleidoscope generates angularly diverse replicated views. A directly attached birefringent filter converts this angular diversity into spectral-response diversity, enabling compact and low-cost snapshot hyperspectral imaging.

System

The prototype is a compact 21 cm add-on built from off-the-shelf optical components. It reconstructs 25 spectral bands from 430 nm to 670 nm without learning-based reconstruction.

BibTeX

@inproceedings{fujiwara2026a2shsi,
  title     = {Compact Low-Cost Hyperspectral Imaging via Angular-to-Spectral Diversity Conversion},
  author    = {Fujiwara, Kazuma and Funatomi, Takuya and Kitano, Kazuya and Fujimura, Yuki and Mukaigawa, Yasuhiro},
  booktitle = {Computer Vision -- ECCV 2026},
  publisher = {Springer},
  year      = {2026}
}