Matched illumination: Using light modulation as a proxy for a color filter that makes a camera more colorimetric

Zhu, Yuteng and Finlayson, Graham D. (2022) Matched illumination: Using light modulation as a proxy for a color filter that makes a camera more colorimetric. Optics Express, 30 (12). pp. 22006-22024. ISSN 1094-4087

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In previous work, it was shown that a camera can theoretically be made more colorimetric–its RGBs become more linearly related to XYZ tristimuli–by placing a specially designed color filter in the optical path. While the prior art demonstrated the principle, the optimal color-correction filters were not actually manufactured. In this paper, we provide a novel way of creating the color filtering effect without making a physical filter: we modulate the spectrum of the light source by using a spectrally tunable lighting system to recast the prefiltering effect from a lighting perspective. According to our method, if we wish to measure color under a D65 light, we relight the scene with a modulated D65 spectrum where the light modulation mimics the effect of color prefiltering in the prior art. We call our optimally modulated light, the matched illumination. In the experiments, using synthetic and real measurements, we show that color measurement errors can be reduced by about 50% or more on simulated data and 25% or more on real images when the matched illumination is used.

Item Type: Article
Additional Information: Acknowledgements: Engineering and Physical Sciences Research Council (EP/S028730/1). The authors would like to express their gratitude to Dietmar Wueller (Image Engineering) for his generous help of measuring the spectral sensitivity functions of the experimental camera. We also would like to thank Dr. Michal Mackiewicz for his help on the illuminator system.
Uncontrolled Keywords: atomic and molecular physics, and optics ,/dk/atira/pure/subjectarea/asjc/3100/3107
Faculty \ School: Faculty of Science > School of Computing Sciences
UEA Research Groups: Faculty of Science > Research Groups > Colour and Imaging Lab
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Depositing User: LivePure Connector
Date Deposited: 19 Jul 2022 15:30
Last Modified: 07 Mar 2023 02:13
DOI: 10.1364/OE.451839


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