1. Introduction
Gait recognition aims to identify people based on their way of walking when the subject is far from the camera or when the collaboration of the subject is not feasible (e.g. subjects wearing protection suits). Previous studies [14], [18] showed that the human gait is a stable and feasible feature over time, even in the case of low frame rates and low image resolution. Thus, gait can be used as a kind of biometric feature to identify people in a robust way, which has motivated its application as a forensic feature [19] in many countries.