Application of radon transform for fast image registration

One of the important steps in image fusion is image registration. The process of determining the spatial transformation that maps the points in the target image to the points in the source image is known as image registration. Various image registration approaches can be classified as area, feature and transform domain based. Choice of approach depends on image contents and application. Area based approach requires more computation time, specially for large images such as satellite images, while feature based approach may not be accurate if significant features are not available in the images. In this paper authors have used the rotation and translation invariant properties of radon transform to find the amount of rotation and translation required to perform registration, i.e. to align the images. Simulation results are shown for different images, with different amount of rotation and translations, to show the accuracy and reliability of the method. Again noise level is also varied, to observe the robustness of the method to noise. The required average computation time is in seconds, depending on the size of images.