1. A method for positioning a two-dimensional (2D) image using a textured three dimensional (3D) model of a region of space, comprising: obtaining a textured 3D model that represents a region of space; acquiring a 2D image that represents at least a portion of the region of space; determining, with respect to the textured 3D model and the acquired 2D image, an initial pose for the acquired 2D image; synthesizing a second 2D image from the textured 3D model based on the initial pose; aligning the acquired 2D image with the second 2D image to obtain a new estimated pose, wherein the aligning comprises: distributing a first set of points in the acquired 2D image using image coordinates, distributing a second set of points in the second 2D image using the same image coordinates, selecting an area surrounding each point in the first set of points, selecting an area surrounding each point in the second set of points, and adjusting a position of one or more of the points in the first set of points or the second set of points based on the selected area surrounding the points of the first set of points and the second set of points; and positioning the acquired 2D image with respect to the textured 3D model based on the new estimated pose.