Nonlinear anisotropic diffusion filtering for multiscale edge enhancement
Nonlinear anisotropic diffusion filtering for multiscale edge enhancement
复制标题
DOI：
10.1088/0266-5611/18/1/312
复制
发表时间：
2002-02-01
期刊：
影响因子：
2.1
通讯作者：
Stollberger, R
中科院分区：
文献类型：
--
作者：
Keeling, SL;Stollberger, R
非线性各向异性扩散滤波是一种基于非线性演化偏微分方程组的方法，它通过去除噪声、保留细节甚至增强边缘来提高图像的质量。然而，众所周知的实现对必须调整以锐化窄范围边缘斜率的参数很敏感；否则，边缘要么模糊，要么呈阶梯状。在这项工作中，发展了非线性各向异性扩散滤波器，它在很大范围的斜率尺度上锐化边缘，并在仅沿特征边界耗散的情况下保守地降低噪声。具体地说，当垂直于水平集的向后扩散与与水平集相切的正向扩散平衡时，锐化的边缘斜率的范围被加宽。此外，通过选择性地朝着减小正常后向扩散的方向，特别是向全变差滤波的方向改变平衡，来降低噪声。文中给出了该滤波器的理论依据，并给出了在合成图像和磁共振图像上与其他非线性各向异性扩散滤波器的计算结果。
Nonlinear anisotropic diffusion filtering is a procedure based on nonlinear evolution partial differential equations which seeks to improve images qualitatively by removing noise while preserving details and even enhancing edges. However, well known implementations are sensitive to parameters which are necessarily tuned to sharpen a narrow range of edge slopes; otherwise, edges are either blurred or staircased. In this work, nonlinear anisotropic diffusion filters have been developed which sharpen edges over a wide range of slope scales and which reduce noise conservatively with dissipation purely along feature boundaries. Specifically, the range of sharpened edge slopes is widened as backward diffusion normal to level sets is balanced with forward diffusion tangent to level sets. Also, noise is reduced by selectively altering the balance toward diminishing normal backward diffusion and particularly toward total variation filtering. The theoretical motivation for the proposed filters is presented together with computational results comparing them with other nonlinear anisotropic diffusion filters on both synthetic images and magnetic resonance images.