Fig. 11

People counting results in terms of mean opportunity error (MOE), MOE for different person–signage distances, mean people error (MPE), and cumulative opportunity error (COE) for Algorithm 1 (A1: red box), Algorithm 2 (A2: dark red box), Algorithm 3 (A3: light green box), and Algorithm 4 (A4: dark green box). When compatible with the system, the results are reported with inference in GPU (filled boxes) and CPU (non-filled boxes). The actual cumulative number of people with OTS across all videos is 646. Results indicate that trackers (A3–4) perform better than detectors (A1–2) for instantaneous (MOE) and, especially, for cumulative (COE) counting where the error obtained by trackers is at least an order of magnitude smaller than that obtained by detectors. COE results suggest that processing a smaller number of frames (e.g., Systems 3 and 4) can benefit the performance for cumulative counting