A method of registering image data of an object with at least one of a location and an orientation of the object, the method comprising: - providing registration tracking data representative of at least one of a spatial location and a spatial orientation of a registration tracker; - providing object tracking data representative of at least one of a spatial location and a spatial orientation of an object tracker adapted to be tracked by a navigation system, wherein the object tracker has a fixed spatial relationship with the object, characterized in that the method further comprises - providing three-dimensional image data generated for the object, the image data being representative of at least a portion of the object and of reference markings associated with the object, wherein the reference markings have a known spatial relationship with the registration tracker adapted to be tracked by the navigation system; - calculating from the registration tracking data and the object tracking data for a given point in time the relative position between the registration tracker and the object tracker; and - generating registered image data representative of at least one of the location and the orientation of the object taking into account the spatial relationship between the reference markings and the registration tracker and the relative position between the registration tracker and the object tracker. - providing registration tracking data representative of at least one of a spatial location and a spatial orientation of a registration tracker; - providing object tracking data representative of at least one of a spatial location and a spatial orientation of an object tracker adapted to be tracked by a navigation system, wherein the object tracker has a fixed spatial relationship with the object, characterized in that the method further comprises - providing three-dimensional image data generated for the object, the image data being representative of at least a portion of the object and of reference markings associated with the object, wherein the reference markings have a known spatial relationship with the registration tracker adapted to be tracked by the navigation system; - calculating from the registration tracking data and the object tracking data for a given point in time the relative position between the registration tracker and the object tracker; and - generating registered image data representative of at least one of the location and the orientation of the object taking into account the spatial relationship between the reference markings and the registration tracker and the relative position between the registration tracker and the object tracker. - providing three-dimensional image data generated for the object, the image data being representative of at least a portion of the object and of reference markings associated with the object, wherein the reference markings have a known spatial relationship with the registration tracker adapted to be tracked by the navigation system; - calculating from the registration tracking data and the object tracking data for a given point in time the relative position between the registration tracker and the object tracker; and - generating registered image data representative of at least one of the location and the orientation of the object taking into account the spatial relationship between the reference markings and the registration tracker and the relative position between the registration tracker and the object tracker.