I. Introduction
Human tracking is a still current challenging task [1]. In a video, people change direction, pass next to each other, are occluded, their detected positions can be unreliable and as such, it is easy to lose or not be able to find a person. These problems are emphasised in distorted contexts such as in top view fisheye cameras. Indeed, a fisheye camera increases the focal distance and embraces a wide field of view [2], [3], making people look inclined and distorted in the image. Consequently, people have irregular movements in the image, their aspect ratio, size and orientation can change drastically as they move. This context is extensively studied for detection [4]–[9] and tracking tasks [10]–[13] as fisheye cameras give 180° of vision and as such find applications in many fields such as security, autonomous driving and aeronautics.