ESPI filtering method based on anisotropic coherence diffusion and Perona-Malik diffusion

Noise reduction is one of the most important concerns in electronic speckle pattern interferometry (ESPI). According to partial differential equation (PDE) filtering theory, we present an anisotropic PDE noise- reduction model based on fringe structure information for interferometric fringe patterns. This model is based on coherence diffusion and Perona-Malik (P-M) diffusion. The former can protect the structure information of fringe pattern, while the latter can effectively filter off the noise inside the fringes. The proposed model generated by the two diffusion methods helps to obtain good effects of denoising and fidelity. ESPI fringes and the phase pattern are tested. Experimental results validate the performance of the proposed filtering model.