This is a paper discribing a fast matting method. It uses a large kernal matting laplacian. A KD-Tree trimap segmentation is also used to decide the size of the kernal.

FuzzyMatte: A Computationally Efficient Scheme for Interactive Matting.More avance than the method bayesien and BELIEF PROPAGATION

learning Based Image Matting 很好的抠图代码, 精度较高-learning Based Image Matting