Thick line center and width estimation are important prob- lems in computer vision. In this paper, we analyze this issue in real sit- uations where we have to deal with some additional diculties, such as the thick line distortion produced by interlaced broadcast video cameras or large shaded areas in the scene. We propose a technique to properly extract the thick lines and their centers using mathematical morpholog- ical operators. In order to illustrate the performance of the method, we present some numerical experiments in real images.