Image registration using subpixel-shifted images for super-resolution

A novel image registration algorithm for super-resolution is proposed. The quality of reconstructed images becomes poor when the arrangement of the registered positions is irregular. However, there are no known ways to acquire the positions arranged regularly without using active cameras. By using a conventional algorithm, the positions registered with subpixel accuracy are often distributed near integer values in the low-resolution grid when the aperture problem occurs, for example, in the case of processing straight edges. Since this phenomenon causes an irregular arrangement, the high- resolution images are reconstructed inefficiently. The proposed method estimates corresponding positions on the shifted image whose image grid is shifted by a desired subpixel displacement. By using the proposed method, the distribution of the corresponding positions is shifted artificially so that the quality of the reconstructed image is improved. The effectiveness of the proposed method is demonstrated in experiments.