A Preliminary Study on the Automatic Visual based Identification of UAV Pilots from Counter UAVs Topics: Assistive Computer Vision; Categorization and Scene Understanding; Event and Human Activity Recognition; Machine Learning Technologies for Vision; Understanding from Wearable and Mobile Cameras; Video Surveillance and Event Detection; Vision for Robotics In Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 5: VISAPP, 582-589, 2020 , Valletta, Malta