A method and an apparatus for creating a correction map for electronic correction of digital projection data from which it is possible to reconstruct a tomosynthetic 3D X-ray image. Furthermore, a method and apparatus are described for electronic correction of digital projection data. In order to allow particularly simple correction of digital projection data, the creation of the correction map includes a reconstruction of the lowermost layer of the 3D X-ray image to be reconstructed from the digital projection data, which lowermost layer corresponds to the detector plane of the digital X-ray detector.
