[4] [4] Weickert J. A review of nonlinear diffusion filtering. in scale-space theory in computer vision, lecture notes in computer science 1252, Berlin :Springer, 1997.3～28

[5] [5] Perona P, Malik J. Scale-space and edge detection using anisotropic diffusion. IEEE Transaction on Pattern Analysis and Machine Intelligence, 1990,12 (7): 629 ～639

[6] [6] Wei G W. Generalized Perona-Malik equation for image restoration. IEEE Signal Processing Letters, 1999, 6(7): 165～167

[8] [8] Weickert J. Coherence-Enhancing dffusion filtering.International Journal of Computer Vision, 1999,31 (2/3): 111～127

[9] [9] Fco Solé A, López A, Sapiro G. Crease enhancement diffusion. Computer Vision and Image Understanding,2001,84(2): 241 ～248

[10] [10] Gilboa G, Zeevi Y Y, Sochen N A. Forward and backward diffusion processes for adaptive image enhancement denosing. IEEE Transaction on Image Processing ,2002,11(7): 689～703