Historical photography-based computer-aided architectural design: Demolished buildings information modeling with reverse engineering functionality

This paper is about single three-point perspective historical photography-based CAAD modeling (amateur camera calibration, pose and 3-d reconstruction) of man-made environments, buildings and monuments, rich in geometrical regularity. The proposed method, gains profit from the presence in the image (historical photography) of three vanishing directions and two orthogonal object edges with known length ration, and then focuses on the graphical estimation of the skew intrinsic parameter of the uncalibrated camera (i.e. the angle of dot's x and y optical axes, in photography plane), dealing in this way even with the skew presence case (non-rectangle dot). The presence of skew is not a negligible factor in historical photography of early 20th century years, due to dot optical axes failure (carelessness manufacturing) or collapse, as well as the twist effect (distortion) from the undocumented film development process in 1920s. The graphical recovery of the skew factor is the main contribution of the paper to the pose and CAAD literature. It is shown that a single three-point perspective amateur photography, even with the presence of skew, is adequate for calibration, pose and planar structure (building façades) recovery, if the usual in building's architecture geometric clues are present (i.e. planarity, orthogonality and parallelism) and some metric data (e.g. length and width of demolished building's dimensions) are available. The proposed method was validated on a simulated cuboid and demonstrated on a number of demolished historical buildings for which only one uncalibrated (and skewed) photography was available. The accuracy evaluation shows that the method is suitable for CAAD modeling applications regarding demolished buildings and monuments of the early 20th century years (2% relative accuracy, i.e. 40 cm for a 20 m façade, included the metric data inaccuracy). The method is of interest for architecture, archaeology, reverse engineering and virtual reality. There are many reasons and motives for 3-d modeling of real-world objects, buildings and scenes, including: virtual reconstruction of historical buildings and monuments that no longer or only partially exist [1]; digital documentation of historical buildings and monuments for restoration purposes in case of fire, flood, war, earthquake, etc.; ability for virtual interaction without the risk of damage; production of e-learning data for educational resources; virtual tourism; virtual museum exhibits; and interactive on demand 3-d visualization of the object, building or scene. 3-d model based applications include: digital documentation of buildings, monuments and sites [2,3]; robot navigation and obstacle recognition [4]; augmented and virtual reality; architectural …