Volumetric calibration enhancements for single-camera light-field PIV
This work presents a volumetric calibration method for single-camera light-field particle image velocimetry (light-field PIV or LF-PIV). The proposed technique makes use of the unique point-like feature of particle light-field images to accurately determine affected pixels for a spatial voxel over a...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/142843 |
| _version_ | 1826124272673751040 |
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| author | Shi, Shengxian Ding, Junfei New, Tze How Liu, You Zhang, Hanmo |
| author2 | School of Mechanical and Aerospace Engineering |
| author_facet | School of Mechanical and Aerospace Engineering Shi, Shengxian Ding, Junfei New, Tze How Liu, You Zhang, Hanmo |
| author_sort | Shi, Shengxian |
| collection | NTU |
| description | This work presents a volumetric calibration method for single-camera light-field particle image velocimetry (light-field PIV or LF-PIV). The proposed technique makes use of the unique point-like feature of particle light-field images to accurately determine affected pixels for a spatial voxel over a relative large measurement volume. A calibration model is derived based on Gaussian optics, which relates a spatial point light source with its confusion circle produced on microlens array (MLA), and optical distortions are accounted for by introducing five calibration parameters. By taking lens defects and misalignment between MLA and image sensor into account, the calibration method can calculate weighting coefficient for particle image reconstruction more accurately than the theoretical ray-tracing method, especially for regions further away from focal plane where light ray deflections are significant due to optical distortions. The volumetric calibration method was validated by simulation tests using synthetic light-field images, and has been successfully applied to a classic vortex-ring LF-PIV measurement, where the measurable range in depth direction was successfully extended and the quality of reconstructed volumetric velocity field was greatly improved. |
| first_indexed | 2024-10-01T06:17:57Z |
| format | Journal Article |
| id | ntu-10356/142843 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:17:57Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1428432023-03-04T17:21:13Z Volumetric calibration enhancements for single-camera light-field PIV Shi, Shengxian Ding, Junfei New, Tze How Liu, You Zhang, Hanmo School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering LF-PIV MLA This work presents a volumetric calibration method for single-camera light-field particle image velocimetry (light-field PIV or LF-PIV). The proposed technique makes use of the unique point-like feature of particle light-field images to accurately determine affected pixels for a spatial voxel over a relative large measurement volume. A calibration model is derived based on Gaussian optics, which relates a spatial point light source with its confusion circle produced on microlens array (MLA), and optical distortions are accounted for by introducing five calibration parameters. By taking lens defects and misalignment between MLA and image sensor into account, the calibration method can calculate weighting coefficient for particle image reconstruction more accurately than the theoretical ray-tracing method, especially for regions further away from focal plane where light ray deflections are significant due to optical distortions. The volumetric calibration method was validated by simulation tests using synthetic light-field images, and has been successfully applied to a classic vortex-ring LF-PIV measurement, where the measurable range in depth direction was successfully extended and the quality of reconstructed volumetric velocity field was greatly improved. MOE (Min. of Education, S’pore) Accepted version 2020-07-03T07:55:35Z 2020-07-03T07:55:35Z 2019 Journal Article Shi, S., Ding, J., New, T. H., Liu, Y., & Zhang, H. (2019). Volumetric calibration enhancements for single-camera light-field PIV. Experiments in Fluids, 60(1), 21-. doi:10.1007/s00348-018-2670-5 0723-4864 https://hdl.handle.net/10356/142843 10.1007/s00348-018-2670-5 2-s2.0-85059524413 1 60 en Experiments in Fluids © 2019 Springer-Verlag GmbH Germany, part of Springer Nature. This is a post-peer-review, pre-copyedit version of an article published in Experiments in Fluids. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00348-018-2670-5. application/pdf |
| spellingShingle | Engineering::Mechanical engineering LF-PIV MLA Shi, Shengxian Ding, Junfei New, Tze How Liu, You Zhang, Hanmo Volumetric calibration enhancements for single-camera light-field PIV |
| title | Volumetric calibration enhancements for single-camera light-field PIV |
| title_full | Volumetric calibration enhancements for single-camera light-field PIV |
| title_fullStr | Volumetric calibration enhancements for single-camera light-field PIV |
| title_full_unstemmed | Volumetric calibration enhancements for single-camera light-field PIV |
| title_short | Volumetric calibration enhancements for single-camera light-field PIV |
| title_sort | volumetric calibration enhancements for single camera light field piv |
| topic | Engineering::Mechanical engineering LF-PIV MLA |
| url | https://hdl.handle.net/10356/142843 |
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