A new localized phase congruency based object detector for X-ray images

In this paper, we present a novel method for automatically computing phase congruency at appropriate scales and orientations. Compared with Kovesi´s phase congruency method, there are two distinct improvements in our method. First, our local phase information can be evaluated in a rotation invariant manner. Therefore, no orientation sampling is required. Second, the phase congruency is computed in a localized way, so there is no need to take all scales into consideration. Thus the computation load is reduced greatly and in the meanwhile this method can gain sub-pixel accuracy. We apply our algorithm to the endotracheal tube detection on X-ray image. Comparative experimental results show the efficiency of our method.