Fitzgerald, NM;
Dainty, C;
Goncharov, AV;
(2017)
Extending the depth of field with chromatic aberration for dual-wavelength iris imaging.
Optics Express
, 25
(25)
pp. 31696-31707.
10.1364/OE.25.031696.
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Abstract
We propose a method of extending the depth of field to twice that achievable by conventional lenses for the purpose of a low cost iris recognition front-facing camera in mobile phones. By introducing intrinsic primary chromatic aberration in the lens, the depth of field is doubled by means of dual wavelength illumination. The lens parameters (radius of curvature, optical power) can be found analytically by using paraxial raytracing. The effective range of distances covered increases with dispersion of the glass chosen and with larger distance for the near object point.
Type: | Article |
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Title: | Extending the depth of field with chromatic aberration for dual-wavelength iris imaging |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1364/OE.25.031696 |
Publisher version: | http://doi.org/10.1364/OE.25.031696 |
Language: | English |
Additional information: | © 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. |
Keywords: | Science & Technology, Physical Sciences, Optics, OF-FIELD, SYSTEM, PHASE, LENS |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Ophthalmology |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10040778 |
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