改进的各向异性扩散方程的超声图像滤波方法.pdfVIP

Vol No Optics and Precision Engineering Jun X T H T P A doi OPE Improved speckle reducing anisotropic diffusion for ultrasound image filtering X U Xianze Z HA O Wencheng X U Feng iu LIU Pan an q p School of E lectronic I nf orm ation W uhan Univ e rs ity W uhan China Cor resp ond ing author Email hncx u w hu e d u cn Abstract In order to eliminate the block eff ect and the blurring details of images caused by the tradi tional speckle reducing anisotropic diff usion an improved anisotropic diff usion algorithm w as pro po sed in w hich a new diff usion coeff icient constituted by the hy perbolic tangent f unction w as used to replace the original diff usion coefficient thus can w ipe off the block eff ect in the unif orm region of im ages A damping f actor w as used to guide the speed of attenuation in the no unif orm area thus reser ving the details and the w eak edges of images In the meanw hile the relative smooth increment w as introduced to monitor the degree of filtering automatically and could stop the iteration process of the partial diff erential equation adaptively T he ex periment s show that the proposed method can not only filter the speckle noises of the images eff ectively but also eliminate the block eff ect problem lead by the traditional anisotropic diff usion In addition it can improve the ability of preserving the detail in f ormations of images and enhance the structural similarity betw een the filtered images an