The Affine GeoTransform is wrongly calculated , while the "positioningInformation" being assumed as AREA_OR_POINT=POINT (point coordinates from a "mapCoordinate" item is assumed to be a center of the pixel). But really the map projection coordinates from "positioningInformation" are AREA_OR_POINT=AREA (the coordinates of pixel corners). That could be proved by equal coordinate values of these point from "geodeticCoordinate" data and corresponding coordinates of GCP data. As a result of that, georeferencing performed from GeoTransform and GCP point data are different with a half pixel shift and slightly wrong scaled.