Flow-of-flow We can stack our layer multiple times, computing the flow-of-flow (FoF). This has the advantage ofcombining more temporal information into a single feature.Our results are shown in Table 5. Applying the TV-L1 algorithm twice gives quite poor performance, as optical flowfeatures do not really satisfy the brightness consistency assumption, as they capture magnitude and direction of motion(shown in Fig. 5). Applying our representation flow layertwice performs significantly better than TV-L1 twice, but still