000061359 001__ 61359 000061359 005__ 20190819101350.0 000061359 0247_ $$2doi$$a10.1364/OE.25.011574 000061359 0248_ $$2sideral$$a98844 000061359 037__ $$aART-2017-98844 000061359 041__ $$aeng 000061359 100__ $$0(orcid)0000-0001-7530-4306$$aArellano, V. 000061359 245__ $$aFast back-projection for non-line of sight reconstruction 000061359 260__ $$c2017 000061359 5060_ $$aAccess copy available to the general public$$fUnrestricted 000061359 5203_ $$aRecent works have demonstrated non-line of sight (NLOS) reconstruction by using the time-resolved signal from multiply scattered light. These works combine ultrafast imaging systems with computation, which back-projects the recorded space-time signal to build a probabilistic map of the hidden geometry. Unfortunately, this computation is slow, becoming a bottleneck as the imaging technology improves. In this work, we propose a new back-projection technique for NLOS reconstruction, which is up to a thousand times faster than previous work, with almost no quality loss. We base on the observation that the hidden geometry probability map can be built as the intersection of the three-bounce space-time manifolds defined by the light illuminating the hidden geometry and the visible point receiving the scattered light from such hidden geometry. This allows us to pose the reconstruction of the hidden geometry as the voxelization of these space-time manifolds, which has lower theoretic complexity and is easily implementable in the GPU. We demonstrate the efficiency and quality of our technique compared against previous methods in both captured and synthetic data. © 2017 Optical Society of America. 000061359 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/TIN2016-78753-P$$9info:eu-repo/grantAgreement/ES/MINECO/TIN2014-61696-EXP$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 682080-CHAMELEON$$9info:eu-repo/grantAgreement/EC/H2020/682080/EU/Intuitive editing of visual appearance from real-world datasets/CHAMELEON 000061359 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/ 000061359 590__ $$a3.356$$b2017 000061359 591__ $$aOPTICS$$b19 / 94 = 0.202$$c2017$$dQ1$$eT1 000061359 592__ $$a1.519$$b2017 000061359 593__ $$aAtomic and Molecular Physics, and Optics$$c2017$$dQ1 000061359 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000061359 700__ $$0(orcid)0000-0002-7503-7022$$aGutierrez, D.$$uUniversidad de Zaragoza 000061359 700__ $$0(orcid)0000-0001-9000-0466$$aJarabo, A. 000061359 7102_ $$15007$$2570$$aUniversidad de Zaragoza$$bDpto. Informát.Ingenie.Sistms.$$cÁrea Lenguajes y Sistemas Inf. 000061359 773__ $$g25, 10 (2017), 11574-11583$$pOpt. express$$tOptics Express$$x1094-4087 000061359 8564_ $$s4256329$$uhttps://zaguan.unizar.es/record/61359/files/texto_completo.pdf$$yVersión publicada 000061359 8564_ $$s98083$$uhttps://zaguan.unizar.es/record/61359/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000061359 909CO $$ooai:zaguan.unizar.es:61359$$particulos$$pdriver 000061359 951__ $$a2019-08-19-09:50:39 000061359 980__ $$aARTICLE