{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T10:45:21Z","timestamp":1777891521432,"version":"3.51.4"},"reference-count":53,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,1,6]],"date-time":"2022-01-06T00:00:00Z","timestamp":1641427200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100014438","name":"Business Finland","doi-asserted-by":"publisher","award":["NSF IUCRC CVDI AMALIA project"],"award-info":[{"award-number":["NSF IUCRC CVDI AMALIA project"]}],"id":[{"id":"10.13039\/501100014438","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Haltian","award":["Mad@Work"],"award-info":[{"award-number":["Mad@Work"]}]},{"DOI":"10.13039\/100015714","name":"Office of the Provost","doi-asserted-by":"publisher","award":["Stroke-Data project"],"award-info":[{"award-number":["Stroke-Data project"]}],"id":[{"id":"10.13039\/100015714","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Social distancing is crucial to restrain the spread of diseases such as COVID-19, but complete adherence to safety guidelines is not guaranteed. Monitoring social distancing through mass surveillance is paramount to develop appropriate mitigation plans and exit strategies. Nevertheless, it is a labor-intensive task that is prone to human error and tainted with plausible breaches of privacy. This paper presents a privacy-preserving adaptive social distance estimation and crowd monitoring solution for camera surveillance systems. We develop a novel person localization strategy through pose estimation, build a privacy-preserving adaptive smoothing and tracking model to mitigate occlusions and noisy\/missing measurements, compute inter-personal distances in the real-world coordinates, detect social distance infractions, and identify overcrowded regions in a scene. Performance evaluation is carried out by testing the system\u2019s ability in person detection, localization, density estimation, anomaly recognition, and high-risk areas identification. We compare the proposed system to the latest techniques and examine the performance gain delivered by the localization and smoothing\/tracking algorithms. Experimental results indicate a considerable improvement, across different metrics, when utilizing the developed system. In addition, they show its potential and functionality for applications other than social distancing.<\/jats:p>","DOI":"10.3390\/s22020418","type":"journal-article","created":{"date-parts":[[2022,1,9]],"date-time":"2022-01-09T23:08:26Z","timestamp":1641769706000},"page":"418","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":33,"title":["A Social Distance Estimation and Crowd Monitoring System for Surveillance Cameras"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4626-5974","authenticated-orcid":false,"given":"Mohammad","family":"Al-Sa\u2019d","sequence":"first","affiliation":[{"name":"Faculty of Information Technology and Communication Sciences, Tampere University, 33720 Tampere, Finland"},{"name":"Faculty of Medicine, Clinicum, University of Helsinki, 00014 Helsinki, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1551-3397","authenticated-orcid":false,"given":"Serkan","family":"Kiranyaz","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Qatar University, Doha, Qatar"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Iftikhar","family":"Ahmad","sequence":"additional","affiliation":[{"name":"TietoEVRY Oy, Keilalahdentie 2-4, 02101 Espoo, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"Sundell","sequence":"additional","affiliation":[{"name":"TietoEVRY Oy, Keilalahdentie 2-4, 02101 Espoo, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Matti","family":"Vakkuri","sequence":"additional","affiliation":[{"name":"Haltian Oy, Yrttipellontie 1 D3, 90230 Oulu, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9788-2323","authenticated-orcid":false,"given":"Moncef","family":"Gabbouj","sequence":"additional","affiliation":[{"name":"Faculty of Information Technology and Communication Sciences, Tampere University, 33720 Tampere, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1268","DOI":"10.1056\/NEJMe2002387","article-title":"COVID-19\u2014Navigating the Uncharted","volume":"382","author":"Fauci","year":"2020","journal-title":"N. 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