It sounds to me like you might be aiming in the direction of unsharp masking. Its probably the most complicated thing that I've ever tried to wrap my head around, photographically speaking, but there are some folks who make it look like riding a bike. Do some searches, both google and APUG, and look for the name Alistair Inglis. I don't know about the first name spelling, but I'm sure about the last name. Cool guy, really knows his stuff.