A mathematical investigation into the design of prefilters that make cameras more colorimetric

Zhu, Yuteng and Finlayson, Graham D. (2020) A mathematical investigation into the design of prefilters that make cameras more colorimetric. Sensors, 20 (23). ISSN 1424-8220

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By placing a color filter in front of a camera we make new spectral sensitivities. The Luther-condition optimization solves for a color filter so that the camera’s filtered sensitivities are as close to being linearly related to the XYZ color matching functions (CMFs) as possible, that is, a filter is found that makes the camera more colorimetric. Arguably, the more general Vora-Value approach solves for the filter that best matches all possible target spectral sensitivity sets (e.g., any linear combination of the XYZ CMFs). A concern that we investigate here is that the filters found by the Luther and Vora-Value optimizations are different from one another. In this paper, we unify the Luther and Vora-Value approaches to prefilter design. We prove that if the target of the Luther-condition optimization is an orthonormal basis—a special linear combination of the XYZ CMFs which are orthogonal and are in unit length—the discovered Luther-filter is also the filter that maximizes the Vora-Value. A key advantage of using the Luther-condition formulation to maximize the Vora-Value is that it is both simpler to implement and converges to its optimal answer more quickly. Experiments validate our method.

Item Type: Article
Uncontrolled Keywords: camera sensors,colorimetry,filter design,optimization method,analytical chemistry,biochemistry,atomic and molecular physics, and optics,instrumentation,electrical and electronic engineering ,/dk/atira/pure/subjectarea/asjc/1600/1602
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: 07 Jan 2021 01:01
Last Modified: 08 Mar 2024 08:30
URI: https://ueaeprints.uea.ac.uk/id/eprint/78079
DOI: 10.3390/s20236882


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