这是改进的TV模型，用于原始噪声图像的边缘检测，代码里还包括PM模型，YK模型等-In this MTV, the diffusion is along the edge direction of the original noisy image(maybe its smoothed version using a Gaussian filter of small scale),it can preserve edge and suppress staircase very well.

this code includes the TV, Perona-Malik, Y-K forth order PDE, and the proposed MTV model.