Fig. 5

Utilization of a spline function for tracking through collisions. The front paw motion pattern in the U−V plane, the front paw motion pattern in the U direction, the hind paw motion pattern in the U−V plane, and the hind paw motion pattern in the U direction for four consecutive strides are illustrated in a, b, c, and d, respectively. In panels a to d, the colors show different strides. Panels b and d show the coordinates shifted up to have the same minimum number (zero). The plots in the U−V plane are shifted to have approximately the same start point. The predicted points for future frames when “collision type II” occurs are shown in e. Front and hind paw predicted locations based on previously tracked points are illustrated in f and g, respectively. Each of these two plots contains the spline function (which is generated from a previously studied mouse with a constant speed of 30 cm/s and averaged from ten strides) before fitting, after fitting of the spline templates to the tracked paw coordinates by applying “frequency of paw locomotion” and not time shift, and final spline function helping the prediction of paws location when “collision type II” happens. It should be noted that fitting is applied for the U coordinates, and the V coordinates are moved accordingly. Finally, two cycles of splines are considered to make sure that the trajectory of coordinates will be continuous