顾及灰度和梯度信息的多模态影像配准算法

基于特征匹配的多模态影像配准方法无法达到像素级配准精度要求。本文研究了一种顾及灰度和梯度信息的多模态影像配准算法。基于马尔科夫随机场（MRF）的非参数化配准模型充分利用多模态影像的图像信息进行相似性测量，同时考虑了灰度及梯度统计信息，求解方法上对值空间进行离散化，提高收敛速度。通过3组多模态影像的配准试验，验证了该算法的可行性。试验表明：本文算法的配准效果优于基于人工刺点的多项式模型配准和只考虑灰度信息的多模态影像配准；与此同时，该算法对于较大形变的影像配准也具有一定的适用性。在空间精度方面，平均配准误差小于1个像素，最大配准误差小于2个像素。

Multimodal Image Registration Algorithm Considering Grayscale and Gradient Information

Multimodal image registration method based on feature matching can‘t satisfy the demands of pixel level registration precision.This paper proposes a multimodal image registration algorithm considering grayscale and gradient information.The nonparametric registration model based on Markov random field (MRF) makes full use of the image information of multimodal image to measure the similarity which considers the grayscale and the gradient statistical information are considered,and the value space is discretized to improve the convergence speed.The algorithm is validated both qualitatively and quantitatively demonstrating its potentials on three groups of multimodal image registration experiments.The result indicates that the proposed algorithm is superior to the polynomial model registration based on manual selection and the multimodal image registration only with gray information only.At the same time,this algorithm has some applicability for multimodal image registration of large deformation.In terms of spatial accuracy,the average registration error is less than 1 pixel and the maximum registration error isless than 2 pixels.