Log-Demons With Driving Force For Large Deformation Image Registration

Large deformation image registration has important research value and application significance in computer vision especially medical image processing.Due to large amount of deformation in the process of registration,the traditional Demons algorithm only uses gradient information of the image to drive the pixel to diffuse,which is difficult to complete the registration if the image is flat or the gradient information is missing at the edge.Therefore,this paper proposes a Log-Demons algorithm based on driving force,which can keep more structural information in the registration process by using the structural tensor of the image as the constraint.This paper uses the driving force based on the descriptor matching to avoid the algorithm to fall into the local optimal and improve the precision in large deformation registration.Finally,this paper builds a high precision registration model based on Log-Demons algorithm for large deformation image registration.The main work of this paper includes:1)Propose Log-Demons algorithm based on structural tensor:the structural tensor of the image can extract more local structure information and is insensitive to external illumination changes.It is incorporated into the Log-Demons algorithm by the tensor conservation criterion to constrain the diffusion of the pixels so that it can maintain a good local structure and obtain a more accurate deformation field.2)Propose a driving-based Log-Demons algorithm:in order to obtain high-precision registration of large deformation images,this paper proposes to use the vector displacement obtained by edge points matching algorithm as a driving force,to pull the motion of the points around the edge of the image,which solves the problem of random diffusion in the case of large deformation,so that it can adapt to large deformation registration.3)Propose the algorithm of obtaining the driving force based on MROGH descriptor matching:in order to obtain more accurate driving force and adapt to the large angle change caused by large deformation,this paper proposes to use MROGH to construct descriptor and perform one-to-one point matching to obtain the displacement vector as the driving force.4)Propose a feature-driven Log-Demons fusion algorithm:take the driving force as a constant and combine the update of Log-Demons with driving force in the way of exponential reduction,so that it can give a great influence at the beginning.When deformation is reduced,it can complete the registration by the Log-Demons own driving force,which can not only speed up the registration process but also reduce the impact of wrong points matching.In the process of calculating update field,this paper proposes to use the property of fusion of the Lie Group to combine the driving force with the update field calculated by Log-Demons,so that the fusion field can also maintain the diffeomorphism.Through the algorithm(1)-(4),the Log-Demons algorithm model based on driving force is constructed,and the large deformation image registration is realized.The method is compared with other methods,and the experimental results show that the method has achieved good results.The results show that the proposed method has a good effect on the simulated image,the real scene large displacement image and the brain image.The method can not only complete the large deformation image registration,but also has better local structure and precision.