Towards the Robustness of Multiple Object Tracking Systems

Due to the wide use of visual perception techniques in safety-critical fields, existing studies have tested the robustness of the essential object detection systems in scenarios with different image content. However, the applications that perceive one video with multiple image frames, such as autonomous driving, usually further require the trajectories of objects. This is mainly realized by combining detecting objects and associating detected objects in frames using multiple object tracking (MOT) systems. Thus, it is also essential to test the robustness of MOT systems, particularly in their exclusive scenarios that involve variety beyond the static image content. In this paper, we propose a novel testing method with five new Metamorphic Relations to realize the robustness test for MOT systems in two typical categories of scenarios, i.e., the speed variety of tracked objects and temporary camera failures. Our method also properly addresses the oracle problem and the lack of test cases for some rare scenarios to make the test efficient and diverse. Finally, we use our method to test three typical MOT systems and effectively reveal numerous and diverse MOT errors. We also extensively discuss the performance of tested systems and summarize two typical scenes where they often misbehave.