Smith, William Alfred Peter orcid.org/0000-0002-6047-0413, Ramamoorthi, Ravi and Tozza, Silvia (2019) Height-from-Polarisation with Unknown Lighting or Albedo. IEEE Transactions on Pattern Analysis and Machine Intelligence. 2875 - 2888. ISSN 0162-8828
Abstract
We present a method for estimating surface height directly from a single polarisation image simply by solving a large, sparse system of linear equations. To do so, we show how to express polarisation constraints as equations that are linear in the unknown height. The local ambiguity in the surface normal azimuth angle is resolved globally when the optimal surface height is reconstructed. Our method is applicable to dielectric objects exhibiting diffuse and specular reflectance, though lighting and albedo must be known. We relax this requirement by showing that either spatially varying albedo or illumination can be estimated from the polarisation image alone using nonlinear methods. In the case of illumination, the estimate can only be made up to a binary ambiguity which we show is a generalised Bas-relief transformation corresponding to the convex/concave ambiguity. We believe that our method is the first passive, monocular shape-from-x technique that enables well-posed height estimation with only a single, uncalibrated illumination condition. We present results on real world data, including in uncontrolled, outdoor illumination.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. |
Keywords: | Azimuth,Bas-relief ambiguity,Estimation,Light sources,Lighting,Refractive index,Shape,Surface reconstruction,albedo estimation,illumination estimation,polarisation,shape-from-x |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Computer Science (York) |
Funding Information: | Funder Grant number EPSRC EP/N028481/1 |
Depositing User: | Pure (York) |
Date Deposited: | 27 Sep 2018 13:00 |
Last Modified: | 16 Oct 2024 15:08 |
Published Version: | https://doi.org/10.1109/TPAMI.2018.2868065 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1109/TPAMI.2018.2868065 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:136316 |