{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T18:20:43Z","timestamp":1776277243377,"version":"3.50.1"},"reference-count":14,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2014,3,27]],"date-time":"2014-03-27T00:00:00Z","timestamp":1395878400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>For robotic harvesting of sweet-pepper fruits in greenhouses a sensor system is required to detect and localize the fruits on the plants. Due to the complex structure of the plant, most fruits are (partially) occluded when an image is taken from one viewpoint only. In this research the effect of multiple camera positions and viewing angles on fruit visibility and detectability was investigated. A recording device was built which allowed to place the camera under different azimuth and zenith angles and to move the camera horizontally along the crop row. Fourteen camera positions were chosen and the fruit visibility in the recorded images was manually determined for each position. For images taken from one position only with the criterion of maximum 50% occlusion per fruit, the fruit detectability (FD) was in no case higher than 69%. The best single positions were the front views and looking with a zenith angle of 60\u00b0 upwards. The FD increased when a combination was made of multiple viewpoint positions. With a combination of five favourite positions the maximum FD was 90%.<\/jats:p>","DOI":"10.3390\/s140406032","type":"journal-article","created":{"date-parts":[[2014,3,27]],"date-time":"2014-03-27T12:28:24Z","timestamp":1395923304000},"page":"6032-6044","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":72,"title":["Fruit Detectability Analysis for Different Camera Positions in Sweet-Pepper"],"prefix":"10.3390","volume":"14","author":[{"given":"Jochen","family":"Hemming","sequence":"first","affiliation":[{"name":"Wageningen UR Greenhouse Horticulture, P.O. Box 644, 6700 AP Wageningen, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jos","family":"Ruizendaal","sequence":"additional","affiliation":[{"name":"Farm Technology Group, Wageningen University, P.O. Box 317, 6700 AH Wageningen,  The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jan","family":"Hofstee","sequence":"additional","affiliation":[{"name":"Farm Technology Group, Wageningen University, P.O. Box 317, 6700 AH Wageningen,  The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eldert","family":"Van Henten","sequence":"additional","affiliation":[{"name":"Wageningen UR Greenhouse Horticulture, P.O. Box 644, 6700 AP Wageningen, The Netherlands"},{"name":"Farm Technology Group, Wageningen University, P.O. Box 317, 6700 AH Wageningen,  The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2014,3,27]]},"reference":[{"key":"ref_1","unstructured":"Homepage of the EU project Clever Robots for Crops. Available online: http:\/\/www.crops-robots.eu."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.13031\/2013.3096","article-title":"A survey of computer vision methods for locating fruit on trees","volume":"43","author":"Ceres","year":"2000","journal-title":"Trans. ASAE"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1007\/PL00013271","article-title":"Localization of spherical fruits for robotic harvesting","volume":"13","author":"Plebe","year":"2000","journal-title":"Mach. Vis. Appl."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/S1881-8366(09)80023-2","article-title":"Machine Vision Algorithm for Robots to Harvest Strawberries in Tabletop Culture Greenhouses","volume":"2","author":"Rajendra","year":"2009","journal-title":"Eng. Agric. Environ. Food"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/0168-1699(93)90058-9","article-title":"Feature extraction of spherical objects in image analysis: An application to robotic citrus Harvesting","volume":"8","author":"Pla","year":"1993","journal-title":"Comput. Electron. Agric."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1023\/A:1020568125418","article-title":"An autonomous robot for harvesting cucumbers in greenhouses","volume":"13","author":"Hemming","year":"2002","journal-title":"Auton. Robot."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.compag.2008.01.018","article-title":"Cherry-harvesting robot","volume":"63","author":"Tanigaki","year":"2008","journal-title":"Comput. Electron. Agric."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"81","DOI":"10.2525\/ecb.48.81","article-title":"A multispectral imaging analysis for enhancing citrus fruit detection","volume":"48","author":"Bulanon","year":"2010","journal-title":"Environ. Control Biol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"831","DOI":"10.1109\/70.897793","article-title":"Robotic melon harvesting","volume":"16","author":"Edan","year":"2000","journal-title":"IEEE Trans. Robot. Autom."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"765","DOI":"10.17660\/ActaHortic.2005.691.94","article-title":"A leaf detection method using image sequences and leaf movement","volume":"691","author":"Hemming","year":"2005","journal-title":"Acta Hortic."},{"key":"ref_11","unstructured":"Connolly, C. (1985, January 25\u201328). The determination of next best views. St. Louis, MO, USA."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1016","DOI":"10.1109\/34.799908","article-title":"A solution to the next best view problem for automated surface acquisition","volume":"21","author":"Pito","year":"1999","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_13","unstructured":"Gil, P., Torres, F., and Reinoso, O. (2007, January 9\u201312). Estimation of camera 3D-position to minimize occlusions. Angers, France."},{"key":"ref_14","unstructured":"Foix, S., Aleny\u00e0, G., and Torras, C. (2011, January 26\u201328). Towards plant monitoring through next best view. Catalonia, Spain."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/14\/4\/6032\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:09:41Z","timestamp":1760216981000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/14\/4\/6032"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,3,27]]},"references-count":14,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2014,4]]}},"alternative-id":["s140406032"],"URL":"https:\/\/doi.org\/10.3390\/s140406032","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,3,27]]}}}