Multimodal Calibration of Portable X-Ray Capture Systems for 3D Reconstruction

We describe a method for non-invasive, accurate and efficient 3D reconstruction of occluded scenes, from a minimal number of X-ray and range scan image acquisitions. The residuals of generalised epipolar constraints (GEC) are incorporated in a highly efficient bundle adjustment minimization, to obtain maximum likelihood estimations of the X-ray image calibration parameters from correspondences between scene points, image points and apparent contours of scene objects. Furthermore, we propose a multimodal template adequate for accurate joint calibration of X-ray and range scan images. It offers crucial advantages for security applications, such as minimal scene occlusion and an agile data acquisition. Finally we describe a shape-from-silhouettes method based on the state of the art, able to reconstruct scene objects with general 3D shapes. We combine these proposals in a full system for 3D reconstruction of occluded scenes, and use it to demonstrate the practical and computational advantages of the methods herein described, with respect to previous proposals, using both synthetic and real data experiments.