Parallel region-based level set method with displacement correction for tracking a single moving object

We proposed a parallel level set method with displacement correction (DC) to solve collision problems during tracking a single moving object. The major collision scenarios are that the target cell collides with other cells, air bubbles, or a wall of the water pool where cells swim. These collisions result in detected contour of the target spreading to the other obstacles which induces target missing and tracking failure. To overcome this problem, we add displacement correction to the procedure of boundary detection once the collision occurs. The intensity summation of inside detected contour is utilized to determine whether collision occurs. After the collision is detected, we translate the current level set function according to the displacement information of target cell. To clarify the ability of our proposed method, we try cell (paramecium) tracking by visual feedback controlling to keep target cell at the center of a view field under a microscope. To reduce computational time, we implement our proposed method in a column parallel vision (CPV) system. We experimentally show that the combination of our proposed method and CPV system can detect the boundary of the target cell within about 2 [ms] for each frame and robustly track cell even when the collision occurs.