MATLAB Source Code for Demons Registration Algorithm

This article presents an image processing technique called the "Demons Registration Algorithm" along with its complete MATLAB source code implementation. This algorithm is specifically designed for medical image registration, where it aligns two images by calculating their similarity metrics through iterative deformation field optimization. The implementation utilizes MATLAB's image processing toolbox functions and demonstrates key components including Gaussian filtering for force computation, gradient calculations for deformation vectors, and interpolation methods for image transformation. We provide comprehensive explanations of the algorithmic principles, including the demons force calculation based on intensity differences and the regularization process using Gaussian smoothing. The MATLAB code showcases practical implementation techniques such as handling multi-resolution registration pyramids, controlling iteration parameters, and visualizing displacement fields. Several practical application examples are included to demonstrate the algorithm's effectiveness in medical imaging scenarios, complete with performance metrics and optimization guidelines. Through this technical documentation, readers will gain deep understanding of demons registration methodology and acquire the skills to implement, customize, and apply this algorithm in their own image processing projects.