People counting using ellipse detection and forward/backward tracing

There are two different people counting methods: (1) counting people across a detecting line in certain time duration and (2) estimating the total number of people in some region at certain time instance. This paper presents a new approach to count the number of people crossing a line of interest (LOI). First, the foreground object silhouettes are extracted described as blobs. Second, we generate the blob linkage based on the one-to-one or one-to-many correspondence between the blobs in every two consecutive frames. Third, we label the number of objects in each blob by applying the ellipse detection technique. However, the occlusion problem jeopardizes the labeling process. Here, we use forward/backward tracing to re-label the number of objects in the occluded blob. In the experiments, we illustrate the effectiveness of our method.