Online EM Algorithm for Background Subtraction

Gaussian mixture model is a popular model in background subtraction and efficient equations have been derived to update GMM parameters previously. In order to compute parameters more accurately while maintain constant computing time per frame, we apply online EM algorithm to update the parameters of Gaussian mixture models. To avoid computing the inverse of covariance matrix, we use isotropic matrix and the corresponding incremental EM equations are derived. Experiments demonstrate that online EM algorithm can give more accurate segment result than previous update equations.