 This is used to construct a Markov random field over the pixel labels, with an energy function that prefers connected regions having the same label, and running a graph cut based optimization to infer their values.As this estimate is likely to be more accurate than the original, taken from the bounding box, this two-step procedure is repeated until convergence.Estimates can be further corrected by the user by pointing out misclassified regions and rerunning the optimization.