Automatic calibration of stereo-cameras using ordinary chess-board patterns

dc.contributor.author	Πρόκος, Αντώνης	el
dc.contributor.author	Καλησπεράκης, Ηλίας	el
dc.contributor.author	Πέτσα, Έλλη	el
dc.contributor.author	Καρράς, Γιώργος	el
dc.date.accessioned	2015-01-28T11:41:20Z
dc.date.available	2015-01-28T11:41:20Z
dc.date.issued	2015-01-28
dc.identifier.uri	http://hdl.handle.net/11400/4924
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	Bundle
dc.subject	Calibration
dc.subject	Stereoscopic cameras
dc.subject	Distortion
dc.subject	Extraction
dc.subject	Non-Metric
dc.subject	Aυτοματοποίηση
dc.subject	Δέσμη
dc.subject	Βαθμονόμηση
dc.subject	Στερεοσκοπικές κάμερες
dc.subject	Παραμόρφωση
dc.subject	Εξαγωγή
dc.subject	Μη-Μετρικό
dc.title	Automatic calibration of stereo-cameras using ordinary chess-board patterns	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.keywordURI	http://id.loc.gov/authorities/subjects/sh85128014
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	2012
heal.bibliographicCitation	Prokos, A., Kalisperakis, I., Petsa, E. and Karras, G. (2012). Automatic calibration of stereo-cameras using ordinary chess-board patterns . International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol.XXXVIII, part 5 (accepted). Available from: http://portal.survey.ntua.gr/main/labs/photo/staff/gkarras/Karras_ISPRS_2012b.pdf	en
heal.abstract	Automation of camera calibration is facilitated by recording coded 2D patterns. Our toolbox for automatic camera calibration using images of simple chess-board patterns is freely available on the Internet. But it is unsuitable for stereo-cameras whose calibration im-plies recovering camera geometry and their true-to-scale relative orientation. In contrast to all reported methods requiring additional specific coding to establish an object space coordinate system, a toolbox for automatic stereo-camera calibration relying on ordinary chess-board patterns is presented here. First, the camera calibration algorithm is applied to all image pairs of the pattern to extract nodes of known spacing, order them in rows and columns, and estimate two independent camera parameter sets. The actual node cor-respondences on stereo-pairs remain unknown. Image pairs of a textured 3D scene are exploited for finding the fundamental matrix of the stereo-camera by applying RANSAC to point matches established with the SIFT algorithm. A node is then selected near the centre of the left image; its match on the right image is assumed as the node closest to the corresponding epipolar line. This yields matches for all nodes (since these have already been ordered), which should also satisfy the 2D epipolar geometry. Measures for avoiding mis-matching are taken. With automatically estimated initial orientation values, a bundle adjustment is performed constraining all pairs on a common (scaled) relative orientation. Ambiguities regarding the actual exterior orientations of the stereo-camera with respect to the pattern are irrelevant. Results from this automatic method show typical precisions not above ¼ pixels for 640x480 web cameras.	en
heal.fullTextAvailability	true
heal.conferenceName	International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences	en
heal.conferenceItemType	full paper