Image registration is the process that overlays two or more images from different sources taken at different times and angles. Art conservators take various scans of paintings and then register them against the original in order to learn more about the working style of the artist, materials used and physical changes throughout time. This paper describes how scale space theory could be applied with a variant of cross-correlation to find the right scale at which to register the input images. From there, the standard state-of-the-art approach is used to register the images. This added step allows automatically registering a wider range of images.