Automatic Registration Algorithm for SAR and Optical Images with Rotation and Scale Invariability
Jinwen Tian · Journal of Astronautics · 2011
Focus on the image registration problems for SAR(Synthetic Aperture Radar) and optical images on condition that existing big scale and angle change,a novel image registration algorithm based on improved SIFT(Scale Invariant Feature Transform) is proposed.First,the enhanced Frost Filter and adaptive local histogram equalization is adopted to improve the common property of SAR and optical images to get enough SIFT points and high represent rate.Then multi-main-direction assignment,normalized cross-correlation measure,clustering analysis,and full hypothesis-proof-test methods are introduced into the algorithm to improve the key point detection,point-pair matching and out-point-pair eliminating performance.Finally,based on the reserved points,the images are registered automatically by using similarity transformation model and least squares method.The experiment results approve that the proposed method is better than SIFT,Harris and other popular state-of-art algorithms both in correct matching probability and positioning accuracy,and would have a good prospect in engineering application.