Outdoor high voltage insulators play a key role in power transmission systems. Due to adverse meteorological conditions, the surface of outdoor overhead insulators frequently covered with snow and ice and exposed to mechanical and electrical stress. This condition leads to insulation breakdowns and power transmission line outages. This paper studies the surface of glass insulator covered with snow, ice and wet condition using image processing techniques. Image filtering methods and state-of-the-art classification algorithms are utilized to discriminate the states of insulator surface using real images of high voltage glass insulator. The obtained results showed that four different insulator surface conditions classified correctly with the accuracy of 99%. An Unnamed Aerial Vehicle (UAV) application is proposed as a prospective data acquisition system.