000087707 001__ 87707 000087707 005__ 20210318091408.0 000087707 0247_ $$2doi$$a10.1038/s41586-019-1461-3 000087707 0248_ $$2sideral$$a112586 000087707 037__ $$aART-2019-112586 000087707 041__ $$aeng 000087707 100__ $$aLiu, Xiaochun 000087707 245__ $$aNon line of sight imaging using phasor field virtual wave optics 000087707 260__ $$c2019 000087707 5060_ $$aAccess copy available to the general public$$fUnrestricted 000087707 5203_ $$aNon-line-of-sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications1,2,3,4,5,6,7,8,9, existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, line-of-sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of linear diffractive wave propagation. Here we show that the problem of non-line-of-sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-line-of-sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional line-of-sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of line-of-sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different line-of-sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-line-of-sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-line-of-sight imaging and promote the development of relevant applications not restricted to laboratory conditions. 000087707 536__ $$9info:eu-repo/grantAgreement/EC/H2020/682080/EU/Intuitive editing of visual appearance from real-world datasets/CHAMELEON$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 682080-CHAMELEON$$9info:eu-repo/grantAgreement/ES/MINECO/TIN2016-78753-P 000087707 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/ 000087707 590__ $$a42.778$$b2019 000087707 591__ $$aMULTIDISCIPLINARY SCIENCES$$b1 / 71 = 0.014$$c2019$$dQ1$$eT1 000087707 592__ $$a14.047$$b2019 000087707 593__ $$aMultidisciplinary$$c2019$$dQ1 000087707 655_4 $$ainfo:eu-repo/semantics/other$$vinfo:eu-repo/semantics/acceptedVersion 000087707 700__ $$0(orcid)0000-0003-4833-8732$$aGuillén, Ibón$$uUniversidad de Zaragoza 000087707 700__ $$aLa Manna, Marco 000087707 700__ $$aHyun Nam, Ji 000087707 700__ $$aAzer Reza, Syed 000087707 700__ $$aHuu Le, Toan 000087707 700__ $$0(orcid)0000-0001-9000-0466$$aJarabo, Adrián$$uUniversidad de Zaragoza 000087707 700__ $$0(orcid)0000-0002-7503-7022$$aGutiérrez, Diego$$uUniversidad de Zaragoza 000087707 700__ $$aVelten, Andreas 000087707 7102_ $$15007$$2570$$aUniversidad de Zaragoza$$bDpto. Informát.Ingenie.Sistms.$$cÁrea Lenguajes y Sistemas Inf. 000087707 773__ $$g572 (2019), 620-623$$pNature$$tNature$$x0028-0836 000087707 8564_ $$s3289696$$uhttps://zaguan.unizar.es/record/87707/files/texto_completo.pdf$$yPostprint 000087707 8564_ $$s489445$$uhttps://zaguan.unizar.es/record/87707/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000087707 909CO $$ooai:zaguan.unizar.es:87707$$particulos$$pdriver 000087707 951__ $$a2021-03-18-09:09:59 000087707 980__ $$aARTICLE