We consider the problem of recovering a high-resolution image from a pair consisting of a complete low-resolution image and a high-resolution but incomplete one. We refer to this task as the image zoom completion (IZC) problem. After discussing possible contexts in which this setting may arise, we study three regularization strategies, giving full details concerning the numerical optimization of the corresponding energies, and discussing the benefits and shortcomings of each method. As the application that leads us to consider the IZC setting concerns images with strong textural content, we evaluate the performance of the proposed methods on a set of Brodatz textures, comparing the results we get with those obtained with two recent state-of-the-art single-image super-resolution algorithms.