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Likewise, adequate image\u2010processing methods are analyzed that highlight key image information, prior to the application of Artificial Neural Network classification algorithms. Twenty\u2010two image\u2010processing methods are reviewed and applied to a broad and unbiased dataset of 1500 sky images recorded in Burgos, Spain, over an extensive experimental campaign. The dataset comprises one hundred images of each CIE standard sky type, previously classified from simultaneous sky scanner data. Color spaces, spectral features, and texture filters image\u2010processing methods are applied. While the use of the traditional RGB color space for image\u2010processing yielded good results (ANN accuracy equal to 86.6%), other color spaces, such as Hue Saturation Value (HSV), which may be more appropriate, increased the accuracy of their global classifications. The use of either the green or the blue monochromatic channels improved sky classification, both for the fifteen CIE standard sky types and for simpler classification into clear, partial, and overcast conditions. The main conclusion was that specific image\u2010processing methods could improve ANN\u2010algorithm accuracy, depending on the image information required for the classification problem.<\/jats:p>","DOI":"10.1155\/2021\/2636157","type":"journal-article","created":{"date-parts":[[2021,12,21]],"date-time":"2021-12-21T04:05:09Z","timestamp":1640059509000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Pixel\u2010Based Image Processing for CIE Standard Sky Classification through ANN"],"prefix":"10.1155","volume":"2021","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9046-7397","authenticated-orcid":false,"given":"D.","family":"Granados-L\u00f3pez","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3233-0525","authenticated-orcid":false,"given":"A.","family":"Garc\u00eda-Rodr\u00edguez","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7064-0308","authenticated-orcid":false,"given":"S.","family":"Garc\u00eda-Rodr\u00edguez","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6471-0261","authenticated-orcid":false,"given":"A.","family":"Su\u00e1rez-Garc\u00eda","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4957-9530","authenticated-orcid":false,"given":"M.","family":"D\u00edez-Mediavilla","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4733-7391","authenticated-orcid":false,"given":"C.","family":"Alonso-Trist\u00e1n","sequence":"additional","affiliation":[]}],"member":"311","published-online":{"date-parts":[[2021,12,20]]},"reference":[{"key":"e_1_2_11_1_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.solener.2019.11.060"},{"volume-title":"A Set of Standard Skies Characterizing Daylight Conditions for Computer and Energy Conscious Design, Final Report","year":"1998","author":"Kittler R.","key":"e_1_2_11_2_2"},{"volume-title":"Spatial Distribution of Daylight\u2013CIE Standard General Sky","year":"2004","author":"Uetani Y.","key":"e_1_2_11_3_2"},{"key":"e_1_2_11_4_2","doi-asserted-by":"publisher","DOI":"10.1088\/1757-899x\/556\/1\/012044"},{"key":"e_1_2_11_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.energy.2016.02.054"},{"key":"e_1_2_11_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.buildenv.2009.11.014"},{"key":"e_1_2_11_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.solener.2019.12.039"},{"key":"e_1_2_11_8_2","doi-asserted-by":"publisher","DOI":"10.1002\/col.5080200118"},{"key":"e_1_2_11_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.renene.2018.03.063"},{"key":"e_1_2_11_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.solener.2021.02.039"},{"key":"e_1_2_11_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.renene.2017.06.013"},{"key":"e_1_2_11_12_2","doi-asserted-by":"publisher","DOI":"10.1109\/LGRS.2014.2356616"},{"key":"e_1_2_11_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.buildenv.2008.11.012"},{"key":"e_1_2_11_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/joc.1891"},{"key":"e_1_2_11_15_2","unstructured":"LiD. 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