Fourier-Mellin transform (FMT) is frequently used in content-based image retrieval and digital image watermarking. This paper extends the application of FMT into image registration and proposes an improved registration algorithm based on FMT for the alignment of images differing in translation, rotation angle, and uniform scale factor. The proposed algorithm can eliminate the conversion from Cartesian to log-polar coordinates, avoid the process of interpolation required in the conversion, and obtain a more signi?cant improvement than the conventional method using cross-correlation. Experiments show that the algorithm is accurate and robust regardless of white noise.