(a) Red contour represents the initial snake on first image (the Sun at 2010-10-05), (b) and (c) cropped view of the tracking process of the selected CBP during time, showing the CBP in frame 1 and frame 37, respectively. The cyan contour is the boundary of the tracked CBP, the red square is the expert’s manual CBP positioning result, and the yellow circle is the PSO-Snake hybrid algorithm’s automated tracking result for CBP’s center of mass.