Bit-pairing codification for binary pattern projection system

Abstract

In a previous work, we proposed a new binary-light projection mechanism that had a much reduced system size that made it particularly suitable for 3D shape inspection of semiconductor products. The inspection speed of the mechanism was governed by the number of required images which also equaled the number of shiftings of the grating. In this paper we address how inspection speed could be gained, i.e., how the number of required images could be reduced, by the incorporation of two neighboring bits in the codification of each scene element. We provide an optimal design of such a codification strategy. A solution to the shifting strategy optimization is also proposed that is applicable to any given binary patterns. Theoretical analysis and real image experiments are presented to illustrate the workability of the solutions. © 2006 IEEE.