TL;DR: This paper shows that using a monochrome event camera and a ball lens, enable colour-from-focus on the visible and near infrared wavelengths just like the cephalopod is hypothesized to do. Thanks to chromatic aberration produced by the ball lens.
Cephalopods exhibit unique colour discrimination capabilities despite having one type of photoreceptors, relying instead on chromatic aberration induced by their ocular optics and pupil shapes to perceive spectral in- formation. We took inspiration from this biological mechanism to design a spectral imaging system that combines a ball lens with an event-based camera. Our approach relies on a motorised system that shifts the focal position, mirroring the adaptive lens motion in cephalopods. This approach has enabled us to achieve wavelength-dependent focusing across the visible light and near-infrared spectrum making the event a spectral sensor. We characterise chromatic aberration effects, using both event-based and conventional frame-based sensors, validating the effectiveness of bio-inspired spectral discrimination both in simulation and in a real setup as well as assessing the spectral discrimination performance. Our proposed approach provides a robust spectral sensing capability without conventional colour filters or computational demosaicing. This approach opens new pathways toward new spectral sensing sys- tems inspired by nature’s evolutionary solutions.
@inproceedings{arja_cephalopod_CVPRW_2025,
title = {Seeing like a Cephalopod: Colour Vision with a Monochrome Event Camera},
author = {Arja, Sami and Kruger, Nimrod and Marcireau, Alexandre and Ralph, Nicholas Owen and Afshar, Saeed and Cohen, Gregory},
booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshop (CVPRW)},
year = {2025}
}