1. A system for detecting and tracking a moving object in a field of view, the system comprising: a moving object indication stage for detecting a candidate object in a series of input video frames depicting the field of view, wherein the moving object indication stage comprises: a short-term change detector for detecting fast-moving objects in the series of input video frames; and a long-term change detector for detecting slow-moving and stopped objects in the series of input video frames; and a track association stage that uses a joint probabilistic graph matching framework to associate an existing track with the candidate object based on analysis of a first set of matching probability terms and a different second set of matching probability terms, and wherein the existing track represents a trajectory of the candidate object, wherein the track association stage comprises: a repository for storing the existing track; and a graph matching processor for matching the candidate object to the existing track using at least one of: a vertex matching feature and a pairwise spatial matching feature.