Python: cv2.createBackgroundSubtractorMOG([history[, nmixtures[, backgroundRatio[, noiseSigma]]]]) → retval
Parameters: 
history – Length of the history.
nmixtures – Number of Gaussian mixtures.
backgroundRatio – Background ratio.
noiseSigma – Noise strength (standard deviation of the brightness or each color channel). 0 means some automatic value.