1. A method of aligning a first image captured by a first camera with at least a segment of an image captured with a second camera, the images captured by the first and second camera having an overlapping field of view, the method comprising: determining, in the first image, an image characteristic value indicative of an image characteristic at a position within the overlapping field of view; determining, in the second image, an image characteristic value indicative of an image characteristic at a position within the overlapping field of view; determining the difference in position between corresponding image characteristic values in the overlapping field of view in the first image and the overlapping field of view in the second image; applying a transform to the first image, the transform adjusting the orientation of the first image relative to the second image, wherein the first and second image are aligned when the difference in position between corresponding image characteristic values in the first and second image is a predetermined amount; selecting at least part of the overlapping field of view in the first image and the second image; displaying a first graph identifying the image characteristic values in the selected part of the overlapping field of view in the first image, each image characteristic value being plotted on the graph at a point corresponding to the position in the first image having such image characteristic value; and overlaying, on the displayed first graph, the image characteristic values in the selected part of the overlapping field of view in the second image, each image characteristic value being plotted on the graph at a point corresponding to the position in the second image having such image characteristic value, whereby the distance in position between the corresponding image characteristic values in the first and second image is determined in accordance with the distance between the plotted image characteristic values.