Undecimated wavelet transform-based image interpolation

Abstract

In this paper, a new wavelet-based image interpolation algorithm is developed for magnifying the image details so that the visibility of tiny features in a digital image is improved. The algorithm takes the LR image as the low-pass filtered subband of an unknown wavelet transformed high resolution image. Then an initial HR image of size twice the LR image is estimated using zero padding of the details. The HR image is transformed via UWT resulting in four subbands, three of which are related with the high frequency components of the image. In the UWT domain, the LL subband is replaced with the initially estimated HR image and applying the inverse UWT, the final HR image is determined. Experiments conducted with both gray level and color images show the superiority of the proposed algorithm over the state-of-the-art interpolation methods. © 2010 Springer-Verlag.