“…Unfortunately this may also cause smoothing of important image structures such that the resulting images appear blurred and not sharp everywhere. Hence, researchers came up with the idea of not applying the smoothness constraint on the resulting image itself, but on the per-pixel decision of the in-focus areas: In [13,14,15,16,17,18] the authors determine an initial decision map by means of a specific sharpness criterion. Subsequently they segment these maps into regions that belong to the same input frames.…”