1. A data processing method, performed by a computer for generating a complete medical image data set from an incomplete image data set, comprising: providing a first image data set which represents an image of a first region of a body, including at least a part of the surface of the body, at a first point in time; providing a second image data set which represents an image of a second region of the body at a second point in time, wherein the second image data set has less dynamic range than the first image data set and/or the second image data set represents only a portion of the first region; and the first region and the second region at least partially overlap; providing a third data set which represents a boundary of the body in the form of points on the surface of the body over the second region, substantially at the second point in time; using the computer to adapt the first image data set to the second image data set by incorporating a distance between points of the third data set and corresponding points in the first image data set; and accepting the adapted first image data set as a complete image data set.