摘要
基于变分水平集方法提出了一种通用的曲面扩散变分模型,其数据项为演化曲面与原曲面的水平集函数Heaviside函数差的平方,规则项为基于整体曲率的通用函数,通过图像扩散模型中的总变差与该模型中的总曲率类比设计该规则项,以实现曲面扩散的任务。为了避免水平集函数的重新初始化,在本文的能量泛函中增加了水平集函数为符号距离函数的惩罚项。所得到的演化方程为4阶偏微分方程,对其对流项采用经典迎风差分格式离散,对其中的扩散项采用中心差分格式。最后通过数值算例验证了模型用于曲面光滑、边缘保持与边缘增强的可行性。
Based on variational level set method, a variational formulation is presented in this paper. The energy functional includes three parts. The first one is data term which is expressed as square of difference between Heavi- side function of the original level set function and the evolved level set function. The second part is a regularized term in general form which is expressed as total curvature similar to total variation term used in image diffusion. The third part is a penalty term to avoid re - initialization of level set function. The derived evolution equation is a fourth order partial differential equation which includes advection term and diffusion term. The advection part is diseretized by u- sing classic upwind difference scheme, and the diffusion part is diseretized by using central difference scheme. Finally, some numerical examples are presented to validate the model for surface diffusion, edge preserving and edge en- hancement.
出处
《计算机仿真》
CSCD
北大核心
2010年第4期240-244,共5页
Computer Simulation
关键词
曲面扩散
变分方法
水平集方法
总曲率
曲面演化
Surface diffusion
Variational method
Level set method
Total curvature
Surface evolution