Method and system for unsynchronized structured lighting

Abstract

A system and method to capture the surface geometry a three-dimensional object in a scene using unsynchronized structured lighting is disclosed. The method and system includes a pattern projector configured and arranged to project a sequence of image patterns onto the scene at a pattern frame rate, a camera configured and arranged to capture a sequence of unsynchronized image patterns of the scene at an image capture rate, and a processor configured and arranged to synthesize a sequence of synchronized image frames from the unsynchronized image patterns of the scene. Each of the synchronized image frames corresponds to one image pattern of the sequence of image patterns.

What is claimed is: 
     
         1 . A method to synthesize a sequence of synchronized image frames synchronized from a sequence of unsynchronized image frames;
 each of the synchronized image frames corresponding to one of a sequence of image patterns;   the synchronized image frames and unsynchronized image frames being image frames of the same width and height;   the image frames comprising a plurality of common pixels;   the method comprising the steps of:
 a) partitioning the plurality of common pixels into a pixel partition; the pixel partition comprising a plurality of pixel sets; the pixel sets being disjoint; each of the plurality of common pixels being a member of one of the pixel sets; 
 b) selecting a pixel set; 
 c) building a pixel set measurement matrix; 
 d) estimating a pixel set projection matrix; the pixel set projection matrix projecting a measurement space vector onto the column space of the pixel set measurement matrix; 
 e) estimating a pixel set system matrix; the system matrix being parameterized by a set of system matrix parameters; 
 f) estimating a pixel set synchronized matrix as a function of the pixel set measurement matrix and the pixel set system matrix; 
 g) repeating steps b) to f) until all the pixels sets have been selected; and 
 h) constructing a sequence of synchronized image frames from the pixel set synchronized matrices. 
   
     
     
         2 . A method as in  claim 1 , where the pixel partition comprises a single pixel set, and the single pixel set contains all the pixels of the image frames. 
     
     
         3 . A method as in  claim 1 , where the number of pixel sets in the pixel partition is equal to the height of the image frames, and each row of the image frames is a pixel set. 
     
     
         4 . A method as in  claim 1 , where the pixel set measurement matrix is modeled as the product of the system matrix times the pixel set synchronized matrix, and the step of estimating the pixel set synchronized matrices reduces to the solution of a linear least-squares problem. 
     
     
         5 . A method as in  claim 1 , where the system matrix is parameterized by an image frame period parameter, an integration time parameter, and a first pattern delay parameter.