python opencv 在图像上进行绘制时，最后记得swap

line = np.array([[lx, ly],[cx, cy]], dtype=np.int32)

trajectoryImg = cv2.polylines(trajectoryImg, [line], 1, (0, 0, 0))

记得swap
# 绘制小鼠的轨迹
trajectoryImg = trajectoryImg.swapaxes(0, 1)