{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,11]],"date-time":"2025-11-11T13:15:32Z","timestamp":1762866932507,"version":"3.41.0"},"reference-count":22,"publisher":"Association for Computing Machinery (ACM)","issue":"9","license":[{"start":{"date-parts":[[2016,8,24]],"date-time":"2016-08-24T00:00:00Z","timestamp":1471996800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["Commun. ACM"],"published-print":{"date-parts":[[2016,8,24]]},"abstract":"<jats:p>\n            We present a novel imaging technique, which we call\n            <jats:italic>femto-photography<\/jats:italic>\n            , to capture and visualize the propagation of light through table-top scenes with an effective exposure time of 1.85 ps per frame. This is equivalent to a resolution of about one half trillion frames per second; between frames, light travels approximately just 0.5 mm. Since cameras with such extreme shutter speed obviously do not exist, we first re-purpose modern imaging hardware to record an ensemble average of repeatable events that are synchronized to a streak sensor, in which the time of arrival of light from the scene is coded in one of the sensor's spatial dimensions. We then introduce reconstruction methods that allow us to visualize the propagation of femtosecond light pulses through the scenes. Given this fast resolution and the finite speed of light, we observe that the camera does not necessarily capture the events in the same order as they occur in reality: we thus introduce the notion of\n            <jats:italic>time-unwarping<\/jats:italic>\n            between the camera's and the world's space--time coordinate systems, to take this into account. We apply our femto-photography technique to visualizations of very different scenes, which allow us to observe the rich dynamics of time-resolved light transport effects, including scattering, specular reflections, diffuse interreflections, diffraction, caustics, and subsurface scattering. Our work has potential applications in artistic, educational, and scientific visualizations; industrial imaging to analyze material properties; and medical imaging to reconstruct subsurface elements. In addition, our time-resolved technique has already motivated new forms of computational photography, as well as novel algorithms for the analysis and synthesis of light transport.\n          <\/jats:p>","DOI":"10.1145\/2975165","type":"journal-article","created":{"date-parts":[[2016,8,26]],"date-time":"2016-08-26T12:25:39Z","timestamp":1472214339000},"page":"79-86","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":10,"title":["Imaging the propagation of light through scenes at picosecond resolution"],"prefix":"10.1145","volume":"59","author":[{"given":"Andreas","family":"Velten","sequence":"first","affiliation":[{"name":"University of Wisconsin, Morgridge Institute for Research, Madison, WI"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Di","family":"Wu","sequence":"additional","affiliation":[{"name":"MIT Media Lab, Cambridge, MA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Belen","family":"Masia","sequence":"additional","affiliation":[{"name":"Universidad de Zaragoza, Zaragoza, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Adrian","family":"Jarabo","sequence":"additional","affiliation":[{"name":"Universidad de Zaragoza, Zaragoza, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christopher","family":"Barsi","sequence":"additional","affiliation":[{"name":"MIT Media Lab, Cambridge, MA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chinmaya","family":"Joshi","sequence":"additional","affiliation":[{"name":"MIT Media Lab, Cambridge, MA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Everett","family":"Lawson","sequence":"additional","affiliation":[{"name":"MIT Media Lab, Cambridge, MA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Moungi","family":"Bawendi","sequence":"additional","affiliation":[{"name":"MIT Department of Chemistry, Cambridge, MA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Diego","family":"Gutierrez","sequence":"additional","affiliation":[{"name":"Universidad de Zaragoza, Zaragoza, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ramesh","family":"Raskar","sequence":"additional","affiliation":[{"name":"MIT Media Lab, Cambridge, MA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2016,8,24]]},"reference":[{"key":"e_1_2_1_1_1","volume-title":"International Image Sensor Workshop","author":"Charbon E.","year":"2007","unstructured":"Charbon , E. 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