Correlation fringe pattern of ESPI generated method based on the orientation partial differential equation

Abstract Fringe-generation is one of the most exciting problems in electronic speckle pattern interferometry. We present an efficient correlation fringe pattern generation method based on the orientation partial differential equation, which derives the fringe pattern with smooth fringes without speckle noise from two original speckle patterns. The average calculations in the correlation method are replaced by the anisotropic filter provided by the oriented partial differential equation. Because the filter along fringe orientation for the entire image can be simply realized based on the oriented partial differential equation, our method does not spoil the phase distribution, and needs not calculate each gray average in the corresponding filter window pixel by pixel. The experimental results show that it is an effective fringe pattern generation method for electronic speckle pattern interferometry.