Local Feature Extraction for Image Super-Resolution

The problem of image super-resolution from a set of low resolution multiview images has recently received much attention and can be decomposed, at least conceptually, into two consecutive steps as: registration and restoration. The ability to accurately register the input images is key to the success and the quality of image super-resolution algorithms. Using recent results from the sampling theory for signals with finite rate of innovation (FRI), we propose in this paper a new technique for subpixel extraction from low resolution images of local features like step edges and corners for image registration. By exploiting the knowledge of the sampling kernel, we are able to locate exactly the step edges on synthetic images. We also present results of full frame super-resolution of real low resolution images using our registration technique. We obtain super-resolved images with a much improved visual quality compared to using a standard local feature detection approach like a subpixel Harris corner detector.