Summarization: The inspection of power transmission lines is an important task that enhances the reliability of Electricity Distribution Network Operators. This task can be performed in a low-cost way using unmanned aircrafts. At the present study, we examine the effectiveness of using basic image processing methods on image data of the power lines acquired by an unmanned aerial vehicle (UAV). The specific UAV was assembled for the present work under the considerations that arise from the purpose of the inspection of power transmission lines. Two methodologies are proposed differing on the preprocessing required in order to detect the location of the lines on the video images. Both proposed methodologies were tested in real-world cases, wit...