An Upsampling Approach to Subpixel Registration Based on Gray Scale Projection

In order to realize high-precision image registration, a subpixel registration algorithm based on gray scale projection is presented. In traditional gray scale projection algorithm, sum of absolute difference is used to perform the correlation process where pixel-level image registration precision is measured. In this paper, we use cross power spectrum method to translate the computing from spatial domain to frequency domain and promote the precision to subpixel level by fast Fourier transform up sampling approach.