METHOD AND APPARATUS FOR RAPID THREE-DIMENSIONAL RESTORATION

摘要

The present invention comprises a method and an apparatus for three-dimensional modelling using the principle of stereo vision with an integrated lighting system used for restoring depth without prior data on the surface reflection. The method includes several initial steps using stereo and radiometric calibration and processes of rectification with a view to obtaining precise results. In addition, an active stereo technique is applied in order to restore dense depth maps from a simple pair of stereo images. This technique is a combination of conventional approaches and stereo photometry and is based on the reflection reciprocity property which considers an arbitrary surface distribution of the reflection. This particular property is achieved if the object to be restored is acquired in the specific lighting conditions provided by the invention. The active stereo technique is followed by a process of in-depth map calibration. The method also includes a procedure for image acquisition for obtaining the sets of images required for calibration, rectification and three-dimensional restoration processes. The apparatus for stereo acquisition of images comprises internal light sources which are automatically communicated by a lighting control to ensure the reciprocity property, a stereo camera head made up of the optics required for acquiring reciprocal stereo images and a PC compatible interface. Positions of external light sources can be considered as an extension of this apparatus. The method and apparatus can be extended to other cameras or light source configurations for acquiring large objects and/or multiple points for view acquisition. This invention is potentially quicker than other 3-D scanners or 3-D restoration systems since it requires only two images in order to obtain deep models of objects with an arbitrary distribution of surface reflection such that, the system is useful in a wide range of applications such as metrology, quality control and medical and dynamic three-dimensional modelling.