Analysis of entropy and fractal dimension to classify the hydrophobicity in polymeric insulators

The aim of this work was classify the hydrophobicity in high power polymeric insulators using digital image processing. To analyze the texture of these images it had been used the calculation of the fractal dimension and entropy that had been compared with the guide of the STRI comparing to contact angle on silicon rubber surfaces. In a way to avoid gradient illuminations caused by natural conditions or contrast variations during analyzes, various kinds of images were produced: as taken from camera, using histogram equalization, White Top-Hat filter and edge detection by Sobel operator. In such a way it was possible to obtain a mathematical relation and to compare these results with those ones published by other researchers, presenting the reliability of this method.