{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:39:15Z","timestamp":1760236755066,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,12,21]],"date-time":"2021-12-21T00:00:00Z","timestamp":1640044800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007835","name":"Silesian University of Technology","doi-asserted-by":"publisher","award":["07\/010\/RGJ20\/0043","07\/010\/SDU\/10-22-01","BK-296\/RIB1\/2021"],"award-info":[{"award-number":["07\/010\/RGJ20\/0043","07\/010\/SDU\/10-22-01","BK-296\/RIB1\/2021"]}],"id":[{"id":"10.13039\/501100007835","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005632","name":"National Centre for Research and Development","doi-asserted-by":"publisher","award":["STRATEGMED1\/234261\/2\/NCBR\/2014"],"award-info":[{"award-number":["STRATEGMED1\/234261\/2\/NCBR\/2014"]}],"id":[{"id":"10.13039\/501100005632","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ministry of Science","award":["07\/010\/BK_21\/1006"],"award-info":[{"award-number":["07\/010\/BK_21\/1006"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Ultra-widefield fluorescein angiography (UWFA) is an emerging imaging modality used to characterise pathologies in the retinal vasculature, such as microaneurysms (MAs) and vascular leakages. Despite its potential value for diagnosis and disease screening, objective quantitative assessment of retinal pathologies by UWFA is currently limited because laborious manual processing is required. In this report, we describe a geometrical method for uneven brightness compensation inherent to UWFA imaging technique. The correction function is based on the geometrical eyeball shape, therefore it is fully automated and depends only on pixel distance from the center of the imaged retina. The method\u2019s performance was assessed on a database containing 256 UWFA images with the use of several image quality measures that show the correction method improves image quality. The method is also compared to the commonly used CLAHE approach and was also employed in a pilot study for vascular segmentation, giving a noticeable improvement in segmentation results. Therefore, the method can be used as an image preprocessing step in retinal UWFA image analysis.<\/jats:p>","DOI":"10.3390\/s22010012","type":"journal-article","created":{"date-parts":[[2021,12,21]],"date-time":"2021-12-21T09:50:43Z","timestamp":1640080243000},"page":"12","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Ultra-Widefield Fluorescein Angiography Image Brightness Compensation Based on Geometrical Features"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7783-2732","authenticated-orcid":false,"given":"Wojciech","family":"Wi\u0119c\u0142awek","sequence":"first","affiliation":[{"name":"Faculty of Biomedical Engineering, Silesian University of Technology, Roosevelta St. 40, 41-800 Zabrze, Poland"}],"role":[{"role":"author","vocab":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5912-2753","authenticated-orcid":false,"given":"Marta","family":"Danch-Wierzchowska","sequence":"additional","affiliation":[{"name":"Faculty of Biomedical Engineering, Silesian University of Technology, Roosevelta St. 40, 41-800 Zabrze, Poland"}],"role":[{"role":"author","vocab":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6942-1821","authenticated-orcid":false,"given":"Marcin","family":"Rudzki","sequence":"additional","affiliation":[{"name":"Faculty of Biomedical Engineering, Silesian University of Technology, Roosevelta St. 40, 41-800 Zabrze, Poland"}],"role":[{"role":"author","vocab":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4057-1898","authenticated-orcid":false,"given":"Bogumi\u0142a","family":"S\u0119dziak-Marcinek","sequence":"additional","affiliation":[{"name":"Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Panewnicka St. 65, 40-760 Katowice, Poland"}],"role":[{"role":"author","vocab":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0935-8880","authenticated-orcid":false,"given":"Slawomir Jan","family":"Teper","sequence":"additional","affiliation":[{"name":"Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Panewnicka St. 65, 40-760 Katowice, Poland"}],"role":[{"role":"author","vocab":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,21]]},"reference":[{"doi-asserted-by":"crossref","unstructured":"Kato, Y., Inoue, M., and Hirakata, A. 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