A unified approach for automatic camera calibration from vanishing points

dc.contributor.author	Γραμματικόπουλος, Λάζαρος	el
dc.contributor.author	Καρράς, Γιώργος	el
dc.contributor.author	Πέτσα, Έλλη	el
dc.contributor.author	Καλησπεράκης, Ηλίας	el
dc.date.accessioned	2015-01-29T10:27:02Z
dc.date.available	2015-01-29T10:27:02Z
dc.date.issued	2015-01-29
dc.identifier.uri	http://hdl.handle.net/11400/5034
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.subject	Automation
dc.subject	Calibration
dc.subject	Distortion
dc.subject	Edge
dc.subject	Extraction
dc.subject	Αυτοματισμός
dc.subject	Βαθμονόμηση
dc.subject	Παραμόρφωση
dc.subject	Εξαγωγή
dc.title	A unified approach for automatic camera calibration from vanishing points	en
heal.type	conferenceItem
heal.classification	Technology
heal.classification	Photogrammetry
heal.classification	Τεχνολογία
heal.classification	Φωτογραμμετρία
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh85133147
heal.classificationURI	http://skos.um.es/unescothes/C02980
heal.classificationURI	N/A-Τεχνολογία
heal.classificationURI	N/A-Φωτογραμμετρία
heal.language	en
heal.access	free
heal.recordProvider	Τ.Ε.Ι. Αθήνας, Σχολή Τεχνολογικών Εφαρμογών, Τμήμα Μηχανικών Πληροφορικής και Μηχανικών Τοπογραφίας & Γεωπληροφορικής	el
heal.publicationDate	2006
heal.bibliographicCitation	Grammatikopoulos, L., Karras, G., Petsa, E. and Kalisperakis, I. (2006). A unified approach for automatic camera calibration from vanishing points. International Archives of the Photogrammetry, Remote Sensing & Spatial Information Sciences, Vol. XXXVI, Part 5 (in CD). Available from: http://www.isprs.org/proceedings/XXXVI/part5/paper/1261_Dresden06.pdf.	en
heal.abstract	A novel approach is presented for automatic camera calibration from single images with three finite vanishing points in mutually or-thogonal directions (or of more independent images having two and/or three such vanishing points). Assuming ‘natural camera’, esti-mation of the three basic elements of interior orientation (camera constant, principal point location), along with the two coefficients of radial-symmetric lens distortion, is possible without any user interaction. First, image edges are extracted with sub-pixel accuracy, linked to segments and subjected to least-squares line-fitting. Next, these line segments are clustered into dominant space directions. In the vanishing point detection technique proposed here, the contribution of each image segment is calculated via a voting scheme, which involves the slope uncertainty of fitted lines to allow a unified treatment of long and short segments. After checking potential vanishing points against certain geometric criteria, the triplet having the highest score indicates the three dominant vanishing points. Coming to camera calibration, a main issue here is the simultaneous adjustment of image point observations for vanishing point esti-mation, radial distortion compensation and recovery of interior orientation in one single step. Thus, line-fitting from vanishing points along with estimation of lens distortion is combined with constraints relating vanishing points to camera parameters. Here, the prin-cipal point may be considered as the zero point of distortion and participate in both sets of equations as a common unknown. If a re-dundancy in vanishing points exists – e.g. when more independent images from the same camera with three, or even two, vanishing points are at hand and are to be combined for camera calibration – such a unified adjustment is undoubtedly advantageous. After the initial adjustment, the points of all segments are corrected for lens distortion to allow linking of collinear segments to longer entities, and the process is repeated. Data from automatic single-image calibrations are reported and evaluated against multi-image bundle ad-justment with satisfactory results. Finally, further interesting topics of study are indicated.	en
heal.fullTextAvailability	true
heal.conferenceName	International Archives of the Photogrammetry, Remote Sensing & Spatial Information Sciences	en
heal.conferenceItemType	full paper