说明：  By using the local regional information which has the ability to enhance the image, an improved active contour model based on level set method is proposed. Defining a novel SPF function with a nonnegative kernel function and local intensity clustering property
(the novel model could draw upon intensity information in local regions at a controllable scale. In addition, the penalizing term which can be called distance regularization term drives the motion of the zero level set toward desired locations. Experimental results for real and synthetic images show the desirable proposed method performances and the model efficiency on intensity inhomogeneities and weak boundaries)