Fig. 14

People counting results in terms of Temporal cumulative opportunity error (TCOE) for varying input frame rate videos in System 1 with GPU (left column) and with CPU (right column) 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). Input frame rates above 1 fps for A4-CPU have been omitted as the algorithm becomes very slow. Longer segments produce a monotonically increase of the error, with steeper slope for detectors (A1–2) than for trackers (A3–4). Higher input frame rates produce a monotonically increase of TCOE for detectors (A1–2) and for the tracker A4. However for tracker A3, TCOE decreases, with a minimum around 6 fps, after which it increases. The considered input frame rates are 0.25, 0.5, 1, 2, 6, 7.5, 10, 15, and 30 frames per second