sentences:  Also on 2006, Google Summer of Code sponsored Tuomas Suutari to create a SQL database back-end for KPhotoAlbum, that although functional, wasn't ready to be included in version 3.0, released December 31.This version improved existing functionalities and added support for viewing video files.Version 4.0 supported KD4 and added "stacking" of images belonging together (like for HDR or panorama images).Version 4.6.0 included face detection.