r.  *  * @see <a href="http://docs.opencv.org/modules/video/doc/motion_analysis_and_object_tracking.html#calcmotiongradient">org.opencv.video.Video.calcMotionGradient</a>  */     public static void calcMotionGradient(Mat mhi, Mat mask, Mat orientation, double delta0, double delta0, int apertureSize)     {          calcMotionGradient_0(mhi.nativeObj, mask.nativeObj, orientation.nativeObj, delta0, delta0