Optical Joint Fourier Transform Correlation for Phase Object Recognition
Several methods can be used for visualizing phase objects, i.e. transparent planar objects whose index of refraction is a function of two spatial coordinates x, y and refractive properties are negligible1. Examples of phase objects are thin biological sections, flames and hot gases fluxes, pellicles, ultrasonic fields ... In this paper, we present a Joint Fourier Transform correlation method2 to recognize or classify automatically without visualization phase objects. The method is applied to the recognition of different strain states in thin plastic samples (polymethyl methacrylate). We also mention the results obtained on rapidly self modifying liquid pellicles which are other phase objects prepared by smearing microscopy cover glasses with a fast evaporating solvent.
KeywordsFocal Plane Ultrasonic Field Phase Object Optical Pattern Input Object
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