Image Feature Extraction Method to Analyze Soft-Mode Turbulence Fluctuation in Nematic Liquid Crystal

Abstract

An electroconvective pattern called soft-mode turbulence (SMT) of homeotropic alignment in MBBA (4’-Methoxy-benzylidene-4-butyl-aniline) nematic liquid crystal appears when an external electric field with a certain frequency applied on the nematic liquid crystal sample at a threshold voltage (V SMT). The threshold voltage will increase with increasing of frequency. SMT fluctuation occurs when V SMT continues to increase at the same frequency. This phenomenon can be analized by applying an image processing tecnique. Based on image feature extraction method, inhomogeneity of SMT patterns can be observed through contrast, correlation, energy, homogeneity, and entropy parameters. Those parameters represent a result in accordance with the image visualization. Significant changes in the value of contrast, energy, homogeneity, and entropy parameters occur at V> V SMT which fluctuation begin. In this experiment the fluctuation begin at V = 27.3 V.