Photography-based façade recovery & 3-d modeling: A CAD application in Cultural Heritage

• Published in: Journal of cultural heritage 2011-07, Vol.12 (3), p.243-252
• Main Authors: Styliadis, Athanasios D., Sechidis, Lazaros A.
• Format: Article
• Language: English
• Subjects: Digital cultural heritage; Historical photography architecture; Image-based CAD; Single view metrology; Uncalibrated imagery
• ISSN: 1296-2074; 1778-3674
• DOI: 10.1016/j.culher.2010.12.008

This paper deals with the problem of monument's façade pose recovery from a single image acquired with a completely uncalibrated camera (e.g. historical photography). The five camera intrinsic parameters are directly representing from the Image of the Absolute Conic (IAC) and the recovering procedure is based on some prior knowledge on camera's aspect ratio ( r) value domain (one independent quadratic constraint on IAC) and monument's geometric properties (four independent linearly constraints on IAC). So, for each r discrete value, the five camera intrinsic parameters are estimated using these five independent constraints on IAC, and then monument's facade pose is recovered and 3-d projective and metric reconstruction is achieved relative to the selected aspect ratio. Following, by back-projecting the reconstructed 3-d model onto the single image on screen (CAD design session) and applying a minimization function on the discrepancy vectors between the 3-d model and the single photography image, the final r value is estimated. This new presence-of-skew stratified self-calibration method, despite the fact that it is an iterative one, is experimentally shown to be advantageous over traditional zero-skew calibration methods, when historical, or on-site, completely uncalibrated photography, of rich in geometric constraints monuments, is concerned. The method is of interest for cultural heritage documentation, digital architecture, archaeology, reverse engineering and virtual reality. Also, the proposed approach can be used in any vision problem where camera self-calibration is involved, either for enhancing robustness or removing ambiguities.