1. A method of aligning data for a target frame and a reference frame, the method comprising: receiving patch data for each of a plurality of reference patches of the reference frame, the patch data comprising a reference direction of a feature in an associated reference patch and a reference signal corresponding to a projection of reference patch image data in a direction substantially perpendicular to the reference direction; determining a shift between at least one of said reference patches and a corresponding target patch in the target frame using the reference signal associated with said reference patch and a target signal corresponding to a projection of the target patch image data in the direction substantially perpendicular to the reference direction associated with said reference patch; determining the alignment data for the target frame using the determined shift for said reference patch; and transforming image data of the target frame using the alignment data.