Automatic camera calibration for cultural heritage application using unstructured planar objects

dc.contributor.author	Adam, K.	en
dc.contributor.author	Καλησπεράκης, Ηλίας	el
dc.contributor.author	Γραμματικόπουλος, Λάζαρος	el
dc.contributor.author	Καρράς, Γιώργος	el
dc.contributor.author	Πέτσα, Έλλη	el
dc.date.accessioned	2015-01-29T12:54:41Z
dc.date.available	2015-01-29T12:54:41Z
dc.date.issued	2015-01-29
dc.identifier.uri	http://hdl.handle.net/11400/5062
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	Camera calibration
dc.subject	Point operator
dc.subject	Radial distortion
dc.subject	Bundle adjustment
dc.subject	Automation
dc.subject	Αυτοματισμός
dc.subject	Κάμερα βαθμονόμησης
dc.title	Automatic camera calibration for cultural heritage application using unstructured planar objects	en
heal.type	conferenceItem
heal.generalDescription	proceedings	en
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	2013-09-02
heal.bibliographicCitation	Adam, K., Kalisperakis, I., Grammatikopoulos, L., Karras, I. and Petsa, I. (2013). Automatic camera calibration for cultural heritage application using unstructured planar objects. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-5/W2, 2013 XXIV International CIPA Symposium, 2-6/09/2013, Strasbourg, France . Available from: http://cipa.icomos.org/fileadmin/template/doc/STRASBOURG/ARCHIVES/isprsarchives-XL-5-W2-1-2013.pdf	en
heal.abstract	As a rule, image-based documentation of cultural heritage relies today on ordinary digital cameras and commercial software. As such projects often involve researchers not familiar with photogrammetry, the question of camera calibration is important. Freely available open-source user-friendly software for automatic camera calibration, often based on simple 2D chess-board patterns, are an answer to the demand for simplicity and automation. However, such tools cannot respond to all requirements met in cultural heritage conserva-tion regarding possible imaging distances and focal lengths. Here we investigate the practical possibility of camera calibration from unknown planar objects, i.e. any planar surface with adequate texture; we have focused on the example of urban walls covered with graffiti. Images are connected pair-wise with inter-image homographies, which are estimated automatically through a RANSAC-based approach after extracting and matching interest points with the SIFT operator. All valid points are identified on all images on which they appear. Provided that the image set includes a ‘fronto-parallel’ view, inter-image homographies with this image are regarded as emulations of image-to-world homographies and allow computing initial estimates for the interior and exterior orientation elements. Following this initialization step, the estimates are introduced into a final self-calibrating bundle adjustment. Measures are taken to discard unsuitable images and verify object planarity. Results from practical experimentation indicate that this method may produce satisfactory results. The authors intend to incorporate the described approach into their freely available user-friendly software tool, which relies on chess-boards, to assist non-experts in their projects with image-based approaches.	en
heal.fullTextAvailability	true
heal.conferenceName	International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, International CIPA Symposium, 2.	en
heal.conferenceItemType	full paper