Integration of active and passive sensing techniques for representing three-dimensional objects

An algorithm is introduced for inferring the structure of three-dimensional (3-D) objects from multiple viewing directions using an integration of active and passive sensing. The structural description of a 3-D object is constructed in two stages: (i) the surface orientation and partial structure are first inferred from a set of single views, and (ii) the visible surface structures inferred from different viewpoints are integrated to complete the description of the 3-D object. In the first stage, an active stripe coding technique is used for recovering visible surface orientation and partial structure. In the second stage, an iterative construction/refinement scheme is used which exploits both passive and active sensing for representing the object surfaces. The final surface structure is recorded in a data structure where the surface contours in a set of parallel planar cross sections are stored. The system construction is inexpensive, and the algorithms introduced are adaptive, versatile, and suitable for applications in dynamic environments