the way you describe it reminds me of a tool in Ps.

it's the midtone adjustment in "image-adjustments-shadows/highlights and you use the "midtone contrast" adjustment at the bottom. it does not change overall contrast, i.e. it will not alter the black or the white portions of an image, and using it with care will seem to sometimes lift a veil in large parts of an image, or seemingly increase contrast and detail in parts of an image where there are small details.

of course, what it does never increases detail (resolution) really, but it can give a very good impression.

i have no idea how this Darbee works though.

See: http://www.blu-ray.com/community/gallery.php?member=Gelli
or: Axiom Gallery