基于分数阶梯度驱动的主动Demons算法研究  

Research on Active Demons Based on Fractional Differentiation Gradient Driving

作　　者：张桂梅[1] 曹红洋 陈阳泉 刘建新[3] 

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330063 [2]加州大学默塞德分校,加利福尼亚默塞德ca95343 [3]西华大学机械工程学院,四川成都610039

出　　处：《电子学报》2016年第12期2834-2841,共8页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61462065);江西省自然科学基金(No.2015BAB207036)

摘　　要：图像非刚性配准在计算机视觉和医学图像有着重要的作用.Demons算法被证明是解决非刚性配准的有效方法,然而存在的Demons非刚性配准算法对灰度均匀和弱纹理区域的图像配准精度低,优化易陷入局部极小导致配准速度缓慢.针对该问题,将R-L（Riemann-Liouville）分数阶微分引入到主动Demons算法中,提出了基于R-L分数阶梯度驱动的主动Demons算法.本文将R-L分数阶梯度代替传统的梯度算子,不但可以增强图像的细节信息,而且可以增强灰度均匀和弱纹理区域的梯度信息,从而提高了图像配准精度和速度.另外,通过实验给出了配准精度与R-L分数阶模板参数之间的关系,从而为模板最佳参数的选取提供了依据.尽管不同类型的图像其最佳参数是不同的,但是其最佳配准阶次一般在0~1之间.理论分析和实验结果均表明,该算法可以用于灰度均匀和弱纹理区域的图像配准,且配准精度和速度都有明显的提高,本文方法是Demons算法应用的一个重要延伸.Non-rigid image registration plays an important role in computer vision and medical image. Demons algo- rithm has been proved to be effective for non-rigid image registration;however, the existing Demons algorithms are limited in registration image for intensity uniformity or weak textile region, which always results in low registration accuracy and ef- ficiency. Aiming at the problem, this paper applies R-L（Riemann-Liouville） fractional differentiation to active Demons, and proposes a new image registration based on fractional differentiation active Demons. In this paper we calculate image gradi- ent using R-L fractional differentiation instead of the traditional gradient function, not only detail feature is strengthened but also image gradient of intensity uniformity and weak textile area is enhanced, thus registration accuracy and efficiency are improved. Additionally, we give the relation curve between registration accuracy and mask parameters, which can guide one to select optimal parameters. Though optimal parameter （order） is different for different images,it is proved the optimal in- terval is between 0 - 1. Theoretical analysis and experiment results show the effectiveness of the proposed method. It is a sig- nificant extension of Demons algorithm.

关 键 词：Riemann-Liouville 分数阶梯度 主动Demons算法 非刚性配准 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]