System and method for high resolution range imaging with slit light source and pattern mask

摘要

A high-resolution range imaging system and method can sense the presence of and determine the position or range of each point on the surface of an object through triangulation calculation methods. A moving pattern of light is projected onto the object to be imaged. This resulting moving light pattern, comprised of vertical planes of light, is achieved by projecting light through a moving mask having a DeBruijn code formed thereon, the light being projected through the mask to provide blurring. The light source has a slit or the like which is between one and two times as wide as the narrowest stripe on the mask. Each light ray of the incoming reflected light pattern is recorded by a detecting device, such as a charge coupled device camera (CCD camera). The detecting device measures the blurring of the light pattern and records the associated gray-scale value, a measurement of the reflected light intensity, at each pixel location. A series of recordings are taken at each pixel location as the structured light pattern moves across the object. A vector defined by the series of gray scale values recorded at each pixel location corresponds to a unique location along the pattern of light. Once the series of gray-scale values is matched to this unique location, the range of each pixel location and a three-dimensional image of the object can be formed using triangulation calculation methods.