A method is provided for estimating parameters of an imaging device with respect to an image of a scene said method comprising the steps of locating a target coordinate system in a scene, using an imaging device to capture an image of the scene, and processing the image using the target coordination system as a reference to estimate the parameters of the imaging device with respect to the image, wherein the target coordinate system comprises at least one planer target and wherein the at least one planar target contains a set of identifiable features with known relative positions.