Image registration model and algorithm for multi-focus images

Accurate registration of multi-focus images is essential in the fields of image fusion and shape from focus. A new image registration model, which is based on the geometry of multi-focus imaging, is presented for multi-focus images. The model contains only one parameter to be calibrated, and the parameter has explicit physical meaning. Golden section search is utilized to calibrate the parameter in our global image registration algorithm. Experimental results show that the model and algorithm can improve registration accuracy of multi-focus images and the method is superior to the widely used method based on affine transformation. Finally, factors affecting the registration error of our method are analyzed by simulation, and suggestions are given to improve the registration accuracy in practical applications. (C) 2016 Elsevier B.V. All rights reserved.