“…The retrospective methods are further classified into filtering, surface fitting, segmentation-based, and histogram-based, etc. Additionally, several valuable reviews about this topic can be found in (Arnold et al, 2001;Belaroussi et al, 2006;Hou, 2006;Sled et al, 1997;Velthuizen et al, 1998;Vovk et al, 2007). …”