Algorithm 4. Fragment of the Python code: drawing setPoint on screen cv2.circle() and self.PID().

# only proceed if the radius meets a minimum size

if radius > 10:⋯# length of min 10 pixel

# draw setpoint on screen—5 pixel red dot

cv2.circle(frame, (int(self.setPointX), int(self.setPointY)), 5, (0, 0, 255), −1)

self.PID(self.setPointX, self.setPointY, x, y)

# PID setpoint actual position in x, y,