Multiscale image registration using scale trace correlation

This paper presents a method for registering images at different magnifications (scales) by treating the problem not only as one of scaling the image coordinates but also as one inherently involving multiresolution information. While some existing methods for multiresolution registration do consider the way the resolution (scale) affects the image, they often consider the image one scale at a time, using geometric properties within that scale. Others use multiscale information, usually to produce more robust results, but only to register same-magnification images (e.g., stereo). A scale trace is the set of values that a single pixel takes on as magnification decreases and the effective point specifications corresponding increases. As such, scale traces capture information across multiple scales. This paper presents a method that uses correlation of scale traces through multiresolution images to find correspondences between images of the same scene at differing magnifications. Because the method relies solely on the multiscale properties of the images themselves and not on spatial correspondence, it is less sensitive to discrete sampling of potential scale factors. Sample results demonstrate that the method is able to accurately identify both the relative position and relative magnification (scale) of the two images