Joint fractional transform correlator based on structured light coding

A new method for 3-D object recognition is proposed. The method combines structured light coding with the joint fractional transform correlator (JFrTC).When projecting sinusoidal grating fringes onto the surface of 3-D objects, the fringes are distorted due to the height of the objects. Then the distorted fringe patterns are regarded as the joint input image used for correlation recognition. Simultaneously, to achieve JFrTC, we can replace either (or both) Fourier transforms in the joint transform correlator (JTC) by a fractional Fourier transform. Four architectures of JFrTC with the distorted fringe pattern and four JFrTC with the intensity map are analyzed in detail. By comparing these different structures, a JFrTC with distorted fringe patterns, especially for the FrT-FT architecture, is suggested to improve the discernment performance, to more decrease the widths of the correlation peaks, and to flexibly change the intensity and position of correlation peaks. Both mathematical analysis and computer simulation results are presented in support of the proposed idea.

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