An Improved Medical Image Registration Algorithm Based on Mutual Information

Medical image registration is widely used in clinical diagnosis, treatment, quality assurance and it's also the prerequisite to realize the fusion and reconstruction. This paper presents an improved medical image registration algorithm based on mutual information. First of all, B-spline gradient operator is adopted to detect edges of the reference image and the floating image and then get binarization image respectively. Next, in order to obtain the centroid coordinates, the moments of the binarization image is calculated. According to the edge detection operator, the rotation angle of the reference image and floating image are obtained. In this paper, improved mutual information (IMI) is used as a measure of similarity between the reference and floating images. The experimental results show that the proposed algorithm has the advantages of low computational complexity and high accuracy, and overcomes the shortcomings of the traditional mutual information easily falling into local optimum.