Intensity-based registration of medical images

Abstract

Mutual information is used widely as a similarity measure for registration of images. In order to improve the robustness of this similarity measure, spatial information is combined with normalised mutual information. In this paper, mutual information is multiplied with a gradient term to integrate spatial information with mutual information and this is taken as similarity measure. The combined measure is a good registration function. For optimisation purpose, fast convergence particle swarm optimisation technique FCPSO is used. In this optimisation method, the diversity of position of single particle is balanced by adding a new variable, particle mean dimension PMD of all particles to the existing position and velocity equation. It reduces the convergence time by reducing the number of iterations in optimisation process.