背景建模方法之高斯混合模型，使用到MOG2。算法快，并且可以进行阴影检测。遍历性：对每一个像素进行建模。作者为Z.Zivkovic-The algorithm similar to the standard Stauffer&Grimson algorithm with additional selection of the number of the Gaussian components based on: "Recursive unsupervised learning of fini