{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,25]],"date-time":"2025-10-25T19:02:54Z","timestamp":1761418974803,"version":"3.37.3"},"reference-count":19,"publisher":"Wiley","license":[{"start":{"date-parts":[[2015,1,1]],"date-time":"2015-01-01T00:00:00Z","timestamp":1420070400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"funder":[{"DOI":"10.13039\/501100002322","name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior","doi-asserted-by":"publisher","award":["543110-7\/2011-2015","71271210"],"award-info":[{"award-number":["543110-7\/2011-2015","71271210"]}],"id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["543110-7\/2011-2015","71271210"],"award-info":[{"award-number":["543110-7\/2011-2015","71271210"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Computational and Mathematical Methods in Medicine"],"published-print":{"date-parts":[[2015]]},"abstract":"<jats:p>This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 \u00d7 2000 \u00d7 2500\u2009mm) with 236 markers (64 above and 88 underwater control points\u2014with 8 common points at water surface\u2014and 92 validation points) was positioned on a 25\u2009m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.). Root Mean Square (RMS) error with homography of control and validations points was lower than without it for surface and underwater cameras (<mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M1\"><mml:mi>P<\/mml:mi><mml:mo>\u2264<\/mml:mo><mml:mn>0.03<\/mml:mn><\/mml:math>). With homography, RMS errors of control and validation points were similar between surface and underwater cameras (<mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M2\"><mml:mi>P<\/mml:mi><mml:mo>\u2265<\/mml:mo><mml:mn>0.47<\/mml:mn><\/mml:math>). Without homography, RMS error of control points was greater for underwater than surface cameras (<mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M3\"><mml:mi>P<\/mml:mi><mml:mo>\u2264<\/mml:mo><mml:mn>0.04<\/mml:mn><\/mml:math>) and the opposite was observed for validation points (<mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M4\"><mml:mi>P<\/mml:mi><mml:mo>\u2264<\/mml:mo><mml:mn>0.04<\/mml:mn><\/mml:math>). It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy.<\/jats:p>","DOI":"10.1155\/2015\/269264","type":"journal-article","created":{"date-parts":[[2015,6,14]],"date-time":"2015-06-14T17:00:51Z","timestamp":1434301251000},"page":"1-8","source":"Crossref","is-referenced-by-count":18,"title":["Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach"],"prefix":"10.1155","volume":"2015","author":[{"given":"Kelly","family":"de Jesus","sequence":"first","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto (FADE-UP), 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory (LABIOMEP), University of Porto (UP), 4200-450 Porto, Portugal"}]},{"given":"Karla","family":"de Jesus","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto (FADE-UP), 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory (LABIOMEP), University of Porto (UP), 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5515-3694","authenticated-orcid":true,"given":"Pedro","family":"Figueiredo","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto (FADE-UP), 4200-450 Porto, Portugal"},{"name":"School of Physical Education, Federal University of Rio Grande do Sul (UFRGS), 90040-060 Porto Alegre, RS, Brazil"}]},{"given":"Jo\u00e3o Paulo","family":"Vilas-Boas","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto (FADE-UP), 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory (LABIOMEP), University of Porto (UP), 4200-450 Porto, Portugal"}]},{"given":"Ricardo Jorge","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto (FADE-UP), 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory (LABIOMEP), University of Porto (UP), 4200-450 Porto, Portugal"}]},{"given":"Leandro Jos\u00e9","family":"Machado","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto (FADE-UP), 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory (LABIOMEP), University of Porto (UP), 4200-450 Porto, Portugal"}]}],"member":"311","reference":[{"year":"2007","key":"1"},{"key":"2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbiomech.2012.01.004"},{"key":"3","doi-asserted-by":"publisher","DOI":"10.1080\/10255842.2012.664637"},{"key":"5","doi-asserted-by":"publisher","DOI":"10.2478\/v10078-011-0037-6"},{"key":"6","doi-asserted-by":"publisher","DOI":"10.1080\/02640414.2012.669043"},{"key":"7","doi-asserted-by":"publisher","DOI":"10.1016\/0021-9290(94)90024-8"},{"key":"8","first-page":"351","volume":"11","year":"2005","journal-title":"Journal of Applied 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