Within the OpenCV libraries, there are other functions that deal with motion. Other Optical Flow technique methods are implemented, such as the Horn and Schunk (cvCalcOpticalFlowHS), block machine (cvCalcOpticalFlowBM), and simple flow (calcOpticalFlowSF) methods. A method to estimate the global movement is also available (calcGlobalOrientation). Finally, there are other methods to obtain backgrounds such as MOG (createBackgroundSubtractorMOG), MOG2 (createBackgroundSubtractorMOG2), and GMG (createBackgroundSubtractorGMG) methods.