Study of mutual information registration based on modified simplex optimization method

A mutual information registration based on modified simplex optimization method is presented in this paper to improve the speed of medical image registration. For two MRI and PET images, the principal axis method is adopted to achieve the rough registration, and the modified simplex algorithm is employed to implement global search using the mutual information as similarity measure. Results indicate that the proposed registration method prevents the optimizing process from falling into local extremum and improves the convergence speed while keeping the precision. The accurate registration of multimodal image with different resolutions is achieved.