<title>Application of communication theory to high-speed structured light illumination</title>

Abstract

Structured light illumination has been used for several decades to extract three-dimensional information from surface topology. Most of the research and development has been in the light structuring methodology and the electronic processing while a unified theoretical description has been lacking. With the advent of programmable spatial light modulators having high frame rates, structured light illumination methods using spatial and temporal patterns are practical. We present structured light systems using spatial light modulation as communication systems and use communications theory in their description. This theory is applied to the specific method of successive binary light striping and the tradeoffs between surface encoding quality and processing speeds are discussed. Shannon's theorem of channel capacity provides an objective measure to evaluate some of these tradeoffs and compare a variety of different approaches to structured light illumination. Another result of our analysis is the unification of structured light projection with pattern recognition. Methods of image recognition using Fourier expansion via orthogonal pattern projection are presented. The results of this analysis establish some physical limitations which guide us to effectively utilize both the methodology and the technology applicable to both 3-D data acquisition as well as pattern recognition. Both numerical and experimental results are presented to demonstrate concepts.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.