Online association by continuous-discrete appearance similarity measurement for multi-object tracking

Abstract

Appearance similarity is of great importance for the association between objects and candidates. Recurrent models and similarity vector are two ways widely used by trackers for calculating similarities between objects and candidates. Recurrent models, like Long Short Term Memory network (LSTM), are capable of modeling the continuous change of object’s appearance in trajectory. But it is prone to identity (ID) switch when only employ recurrent models as appearance model. The similarity vector way is able to maintain correct IDs for objects when they reappear. But association fails easily when the object is partially occluded and similarity vector is used as the only appearance model. To obtain more accurate and robust appearance similarity, in this paper, we propose an online association by continuous-discrete appearance similarity measurement, OA-CDASM, for multi-object tracking. For continuous perspective, the concept of “smoothness” is proposed to explicitly model and use the continuous and smooth change of object’s appearance in trajectory. For discrete perspective, similarity vector is employed. By taking both continuous smoothness and discrete similarity vector into consideration, we can get the continuous-discrete appearance similarity measurement, CDASM, and further perform online association based on CDASM. Experimental results on three public benchmarks demonstrate the effectiveness of our work.