基于Nakagami分布的自适应斑点抑制与边缘增强方法

超声图像中的特殊斑点噪声严重影响了图像质量,针对此问题提出了一种基于Nakagami分布的自适应斑点抑制与边缘增强方法.根据斑点噪声的Nakagami分布模型,设计一个基于斑点局部统计特性的自适应滤波器.并应用"窄条"技术以不同方向与长度的"窄条"来近似图像的局部线性特性,滤波区域采用"窄条"代替常用的方形窗口,其中"窄条"的方向由假设试验优化方法确定,"窄条"长度与斑点的局部统计特性相关.实验证明,该方法在抑制斑点噪声、保留与增强图像边缘和细节方面均具有良好的性能.

An Adaptive Speckle Suppression and Edge Enhancement Method Based on Nakagami Distribution

Ultrasonic images suffer from a special kind of noise called speckle.An adaptive speckle suppression and edge enhancement method based on Nakagami distribution is presented.An adaptive filter is designed by the Nakagami distribution model of speckle.The stick technique what utilizes sticks with different size and various orientations is applied to locally approximate certain linear features of image.The local region is a stick instead of a usual window,the orientation of sticks is decided by hypothesis test optimizing method and the length of sticks is concerned with local statistical feature of speckle.The effectiveness in speckle suppression and edge preservation and enhancement of the proposed filter is demonstrated on ultrasound images of prostate.