A COMPUTATIONAL FRAMEWORK FOR POINT CLOUD CONSTRUCTION USING DIGITAL PROJECTION PATTERNS

Many reverse engineering and inspection applications require generation of point clouds representing faces of phys ical objects. This paper describes a computational framework fo r constructing point clouds using digital projection patter ns. The basic principle behind the approach is to project known patt erns on the object using a digital projector. A digital camera is t hen used to take images of the object with the known projection pa tterns imposed on it. Due to the presence of 3-D faces of the object, the projection patterns appear distorted in the image s. The images are analyzed to construct the 3-D point cloud that is c apable of introducing the observed distortions in the images . The approach described in this paper presents three advances ov er the previously developed approaches. First, it is capable o f working with the projection patterns that have variable fringe w idths and curved fringes and hence can provide improved accuracy. Second, our algorithm minimizes the number of images needed for creating the 3-D point cloud. Finally, we use a hybrid approach that uses a combination of reference plane images and estimated system parameters to construct the point cloud. Thi s approach provides good run-time computational performance a nd