{"id":"https://openalex.org/W3128482972","doi":"https://doi.org/10.3390/jimaging7020021","title":"Critical Aspects of Person Counting and Density Estimation","display_name":"Critical Aspects of Person Counting and Density Estimation","publication_year":2021,"publication_date":"2021-01-31","ids":{"openalex":"https://openalex.org/W3128482972","doi":"https://doi.org/10.3390/jimaging7020021","mag":"3128482972","pmid":"https://pubmed.ncbi.nlm.nih.gov/34460620"},"language":"en","primary_location":{"id":"doi:10.3390/jimaging7020021","is_oa":true,"landing_page_url":"https://doi.org/10.3390/jimaging7020021","pdf_url":"https://www.mdpi.com/2313-433X/7/2/21/pdf?version=1612867315","source":{"id":"https://openalex.org/S2736465063","display_name":"Journal of Imaging","issn_l":"2313-433X","issn":["2313-433X"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Imaging","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj","pubmed"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://www.mdpi.com/2313-433X/7/2/21/pdf?version=1612867315","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5082826461","display_name":"Roland Perko","orcid":"https://orcid.org/0000-0003-3374-4201"},"institutions":[{"id":"https://openalex.org/I13402291","display_name":"Joanneum Research","ror":"https://ror.org/049bdss47","country_code":"AT","type":"facility","lineage":["https://openalex.org/I13402291"]}],"countries":["AT"],"is_corresponding":true,"raw_author_name":"Roland Perko","raw_affiliation_strings":["Joanneum Research Forschungsgesellschaft mbH, DIGITAL, Remote Sensing and Geoinformation, 8010 Graz, Austria"],"raw_orcid":"https://orcid.org/0000-0003-3374-4201","affiliations":[{"raw_affiliation_string":"Joanneum Research Forschungsgesellschaft mbH, DIGITAL, Remote Sensing and Geoinformation, 8010 Graz, Austria","institution_ids":["https://openalex.org/I13402291"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5058695482","display_name":"Manfred Klopschitz","orcid":null},"institutions":[{"id":"https://openalex.org/I13402291","display_name":"Joanneum Research","ror":"https://ror.org/049bdss47","country_code":"AT","type":"facility","lineage":["https://openalex.org/I13402291"]}],"countries":["AT"],"is_corresponding":false,"raw_author_name":"Manfred Klopschitz","raw_affiliation_strings":["Joanneum Research Forschungsgesellschaft mbH, DIGITAL, Remote Sensing and Geoinformation, 8010 Graz, Austria"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Joanneum Research Forschungsgesellschaft mbH, DIGITAL, Remote Sensing and Geoinformation, 8010 Graz, Austria","institution_ids":["https://openalex.org/I13402291"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5070668350","display_name":"Alexander Alm\u00e9r","orcid":null},"institutions":[{"id":"https://openalex.org/I13402291","display_name":"Joanneum Research","ror":"https://ror.org/049bdss47","country_code":"AT","type":"facility","lineage":["https://openalex.org/I13402291"]}],"countries":["AT"],"is_corresponding":false,"raw_author_name":"Alexander Almer","raw_affiliation_strings":["Joanneum Research Forschungsgesellschaft mbH, DIGITAL, Remote Sensing and Geoinformation, 8010 Graz, Austria"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Joanneum Research Forschungsgesellschaft mbH, DIGITAL, Remote Sensing and Geoinformation, 8010 Graz, Austria","institution_ids":["https://openalex.org/I13402291"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5014686562","display_name":"Peter M. Roth","orcid":"https://orcid.org/0000-0001-9566-1298"},"institutions":[{"id":"https://openalex.org/I62916508","display_name":"Technical University of Munich","ror":"https://ror.org/02kkvpp62","country_code":"DE","type":"education","lineage":["https://openalex.org/I62916508"]}],"countries":["DE"],"is_corresponding":false,"raw_author_name":"Peter M. Roth","raw_affiliation_strings":["Data Science in Earth Observation, Technical University of Munich, 82024 Taufkirchen, Ottobrunn, Germany"],"raw_orcid":"https://orcid.org/0000-0001-9566-1298","affiliations":[{"raw_affiliation_string":"Data Science in Earth Observation, Technical University of Munich, 82024 Taufkirchen, Ottobrunn, Germany","institution_ids":["https://openalex.org/I62916508"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5082826461"],"corresponding_institution_ids":["https://openalex.org/I13402291"],"apc_list":{"value":1600,"currency":"CHF","value_usd":1782},"apc_paid":{"value":1600,"currency":"CHF","value_usd":1782},"fwci":0.6326,"has_fulltext":false,"cited_by_count":8,"citation_normalized_percentile":{"value":0.64904341,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":91,"max":97},"biblio":{"volume":"7","issue":"2","first_page":"21","last_page":"21"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10331","display_name":"Video Surveillance and Tracking Methods","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10331","display_name":"Video Surveillance and Tracking Methods","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10036","display_name":"Advanced Neural Network Applications","score":0.9986000061035156,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10812","display_name":"Human Pose and Action Recognition","score":0.993399977684021,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.8216477036476135},{"id":"https://openalex.org/keywords/ambiguity","display_name":"Ambiguity","score":0.718447208404541},{"id":"https://openalex.org/keywords/ground-truth","display_name":"Ground truth","score":0.6246041655540466},{"id":"https://openalex.org/keywords/convolutional-neural-network","display_name":"Convolutional neural network","score":0.6081873178482056},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.5915377140045166},{"id":"https://openalex.org/keywords/baseline","display_name":"Baseline (sea)","score":0.5757205486297607},{"id":"https://openalex.org/keywords/density-estimation","display_name":"Density estimation","score":0.562609076499939},{"id":"https://openalex.org/keywords/machine-learning","display_name":"Machine learning","score":0.5325243473052979},{"id":"https://openalex.org/keywords/estimation","display_name":"Estimation","score":0.526762843132019},{"id":"https://openalex.org/keywords/limit","display_name":"Limit (mathematics)","score":0.5074576735496521},{"id":"https://openalex.org/keywords/field","display_name":"Field (mathematics)","score":0.4997673034667969},{"id":"https://openalex.org/keywords/function","display_name":"Function (biology)","score":0.4323081970214844},{"id":"https://openalex.org/keywords/pattern-recognition","display_name":"Pattern recognition (psychology)","score":0.32846465706825256},{"id":"https://openalex.org/keywords/statistics","display_name":"Statistics","score":0.15774688124656677},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.11346745491027832}],"concepts":[{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.8216477036476135},{"id":"https://openalex.org/C2780522230","wikidata":"https://www.wikidata.org/wiki/Q1140419","display_name":"Ambiguity","level":2,"score":0.718447208404541},{"id":"https://openalex.org/C146849305","wikidata":"https://www.wikidata.org/wiki/Q370766","display_name":"Ground truth","level":2,"score":0.6246041655540466},{"id":"https://openalex.org/C81363708","wikidata":"https://www.wikidata.org/wiki/Q17084460","display_name":"Convolutional neural network","level":2,"score":0.6081873178482056},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.5915377140045166},{"id":"https://openalex.org/C12725497","wikidata":"https://www.wikidata.org/wiki/Q810247","display_name":"Baseline (sea)","level":2,"score":0.5757205486297607},{"id":"https://openalex.org/C189508267","wikidata":"https://www.wikidata.org/wiki/Q17088227","display_name":"Density estimation","level":3,"score":0.562609076499939},{"id":"https://openalex.org/C119857082","wikidata":"https://www.wikidata.org/wiki/Q2539","display_name":"Machine learning","level":1,"score":0.5325243473052979},{"id":"https://openalex.org/C96250715","wikidata":"https://www.wikidata.org/wiki/Q965330","display_name":"Estimation","level":2,"score":0.526762843132019},{"id":"https://openalex.org/C151201525","wikidata":"https://www.wikidata.org/wiki/Q177239","display_name":"Limit (mathematics)","level":2,"score":0.5074576735496521},{"id":"https://openalex.org/C9652623","wikidata":"https://www.wikidata.org/wiki/Q190109","display_name":"Field (mathematics)","level":2,"score":0.4997673034667969},{"id":"https://openalex.org/C14036430","wikidata":"https://www.wikidata.org/wiki/Q3736076","display_name":"Function (biology)","level":2,"score":0.4323081970214844},{"id":"https://openalex.org/C153180895","wikidata":"https://www.wikidata.org/wiki/Q7148389","display_name":"Pattern recognition (psychology)","level":2,"score":0.32846465706825256},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.15774688124656677},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.11346745491027832},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.0},{"id":"https://openalex.org/C127313418","wikidata":"https://www.wikidata.org/wiki/Q1069","display_name":"Geology","level":0,"score":0.0},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.0},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.0},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.0},{"id":"https://openalex.org/C162324750","wikidata":"https://www.wikidata.org/wiki/Q8134","display_name":"Economics","level":0,"score":0.0},{"id":"https://openalex.org/C187736073","wikidata":"https://www.wikidata.org/wiki/Q2920921","display_name":"Management","level":1,"score":0.0},{"id":"https://openalex.org/C78458016","wikidata":"https://www.wikidata.org/wiki/Q840400","display_name":"Evolutionary biology","level":1,"score":0.0},{"id":"https://openalex.org/C111368507","wikidata":"https://www.wikidata.org/wiki/Q43518","display_name":"Oceanography","level":1,"score":0.0},{"id":"https://openalex.org/C185429906","wikidata":"https://www.wikidata.org/wiki/Q1130160","display_name":"Estimator","level":2,"score":0.0}],"mesh":[],"locations_count":4,"locations":[{"id":"doi:10.3390/jimaging7020021","is_oa":true,"landing_page_url":"https://doi.org/10.3390/jimaging7020021","pdf_url":"https://www.mdpi.com/2313-433X/7/2/21/pdf?version=1612867315","source":{"id":"https://openalex.org/S2736465063","display_name":"Journal of Imaging","issn_l":"2313-433X","issn":["2313-433X"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Imaging","raw_type":"journal-article"},{"id":"pmid:34460620","is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/34460620","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of imaging","raw_type":null},{"id":"pmh:oai:doaj.org/article:c7a2a17eb4f24cfbb473dd84a9204328","is_oa":true,"landing_page_url":"https://doaj.org/article/c7a2a17eb4f24cfbb473dd84a9204328","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Journal of Imaging, Vol 7, Iss 2, p 21 (2021)","raw_type":"article"},{"id":"pmh:oai:pubmedcentral.nih.gov:8321281","is_oa":true,"landing_page_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/8321281","pdf_url":null,"source":{"id":"https://openalex.org/S2764455111","display_name":"PubMed Central","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"J Imaging","raw_type":"Text"}],"best_oa_location":{"id":"doi:10.3390/jimaging7020021","is_oa":true,"landing_page_url":"https://doi.org/10.3390/jimaging7020021","pdf_url":"https://www.mdpi.com/2313-433X/7/2/21/pdf?version=1612867315","source":{"id":"https://openalex.org/S2736465063","display_name":"Journal of Imaging","issn_l":"2313-433X","issn":["2313-433X"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Imaging","raw_type":"journal-article"},"sustainable_development_goals":[],"awards":[{"id":"https://openalex.org/G4519649436","display_name":null,"funder_award_id":"854747 and 879709","funder_id":"https://openalex.org/F4320323031","funder_display_name":"\u00d6sterreichische Forschungsf\u00f6rderungsgesellschaft"}],"funders":[{"id":"https://openalex.org/F4320323031","display_name":"\u00d6sterreichische Forschungsf\u00f6rderungsgesellschaft","ror":"https://ror.org/028jc0449"}],"has_content":{"grobid_xml":false,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W3128482972.pdf"},"referenced_works_count":54,"referenced_works":["https://openalex.org/W231968962","https://openalex.org/W1003853626","https://openalex.org/W1542079534","https://openalex.org/W1686810756","https://openalex.org/W1885434661","https://openalex.org/W1897582057","https://openalex.org/W1910776219","https://openalex.org/W1964719110","https://openalex.org/W2003152501","https://openalex.org/W2031342017","https://openalex.org/W2037227137","https://openalex.org/W2049856457","https://openalex.org/W2072232009","https://openalex.org/W2097324787","https://openalex.org/W2104974755","https://openalex.org/W2109255472","https://openalex.org/W2117539524","https://openalex.org/W2121864252","https://openalex.org/W2123175289","https://openalex.org/W2138948290","https://openalex.org/W2145983039","https://openalex.org/W2150123015","https://openalex.org/W2151103935","https://openalex.org/W2158437588","https://openalex.org/W2159564241","https://openalex.org/W2161969291","https://openalex.org/W2182680597","https://openalex.org/W2193145675","https://openalex.org/W2340897893","https://openalex.org/W2463631526","https://openalex.org/W2493229751","https://openalex.org/W2741077351","https://openalex.org/W2788040570","https://openalex.org/W2886443245","https://openalex.org/W2895051362","https://openalex.org/W2949162858","https://openalex.org/W2952888378","https://openalex.org/W2953139137","https://openalex.org/W2963035940","https://openalex.org/W2963037989","https://openalex.org/W2964203052","https://openalex.org/W2964209782","https://openalex.org/W2967069910","https://openalex.org/W2975467257","https://openalex.org/W2981353488","https://openalex.org/W2983249795","https://openalex.org/W3000068949","https://openalex.org/W3027606690","https://openalex.org/W3033135512","https://openalex.org/W3081436178","https://openalex.org/W3106250896","https://openalex.org/W6681368121","https://openalex.org/W6683411478","https://openalex.org/W6772656625"],"related_works":["https://openalex.org/W2353179089","https://openalex.org/W2923538289","https://openalex.org/W2383111961","https://openalex.org/W2365952365","https://openalex.org/W2353125546","https://openalex.org/W2352448290","https://openalex.org/W2470643824","https://openalex.org/W2380820513","https://openalex.org/W4400595174","https://openalex.org/W2913146933"],"abstract_inverted_index":{"Many":[0],"scientific":[1],"studies":[2],"deal":[3,97],"with":[4,98],"person":[5,146,161,178],"counting":[6],"and":[7,42,65,117,148],"density":[8,149,162,179],"estimation":[9,163,180],"from":[10],"single":[11],"images.":[12],"Recently,":[13],"convolutional":[14],"neural":[15],"networks":[16],"(CNNs)":[17],"have":[18],"been":[19],"applied":[20],"for":[21,135],"these":[22,63,69,75,82],"tasks.":[23],"Even":[24],"though":[25],"often":[26,33],"better":[27],"results":[28,129],"are":[29,39],"reported,":[30],"it":[31],"is":[32],"not":[34],"clear":[35],"where":[36],"the":[37,44,50,59,103,108,123,138,143,165,175,188],"improvements":[38],"resulting":[40],"from,":[41],"if":[43],"proposed":[45],"approaches":[46],"would":[47,171],"generalize.":[48],"Thus,":[49],"main":[51],"goal":[52],"of":[53,62,105,119,142,145,159,177],"this":[54,85,152],"paper":[55],"was":[56],"to":[57,66,80,96,173],"identify":[58],"critical":[60],"aspects":[61],"tasks":[64],"show":[67,78,130],"how":[68,79],"limit":[70],"state-of-the-art":[71],"approaches.":[72],"Based":[73],"on":[74],"findings,":[76],"we":[77,87,94,154],"mitigate":[81],"limitations.":[83],"To":[84],"end,":[86],"implemented":[88],"a":[89,156],"CNN-based":[90,160],"baseline":[91,139],"approach,":[92],"which":[93],"extended":[95],"identified":[99],"problems.":[100],"These":[101],"include":[102],"discovery":[104],"bias":[106],"in":[107,113,140,181,187],"reference":[109],"data":[110],"sets,":[111],"ambiguity":[112],"ground":[114],"truth":[115],"generation,":[116],"mismatching":[118],"evaluation":[120,189],"metrics":[121],"w.r.t.":[122],"training":[124],"loss":[125],"function.":[126],"The":[127],"experimental":[128],"that":[131],"our":[132,169],"modifications":[133],"allow":[134,172],"significantly":[136],"outperforming":[137],"terms":[141],"accuracy":[144],"counts":[147],"estimation.":[150],"In":[151],"way,":[153],"get":[155],"deeper":[157],"understanding":[158],"beyond":[164],"network":[166],"architecture.":[167],"Furthermore,":[168],"insights":[170],"advance":[174],"field":[176],"general":[182],"by":[183],"highlighting":[184],"current":[185],"limitations":[186],"protocols.":[190]},"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2023,"cited_by_count":2},{"year":2022,"cited_by_count":3},{"year":2021,"cited_by_count":2}],"updated_date":"2026-07-22T07:51:19.307946","created_date":"2025-10-10T00:00:00"}
