a new rstb invariant image template matching based on log-spectrum and modified ica

template matching is a widely used technique in many of image processing and machine vision applications. in this paper we propose a new as well as a fast and reliable template matching algorithm which is invariant to rotation, scale, translation and brightness (rstb) changes. for this purpose, we adopt the idea of ring projection transform (rpt) of image. in the proposed algorithm, two novel suggestions are offered that significantly increase the precision and performance of the previous methods. first, our algorithm works with log-spectrum of image instead of the image itself, this change increases the accuracy of matching, and secondly for boosting the speed of the searching strategy, a new and modified version of imperialist competitive algorithm, mica, is presented. this matching procedure avoids the searching algorithm from being trapped in local minimum by taking advantage of adding a modification step to ica. the simulation results show the superiority of proposed method in comparison with the previous ones.