Quote from: msiegel;155789
en... enhance?
Tricks like unsharp mask are just an illusion, making the viewer perceive a level of sharpness without actually restoring detail.
Consider this picture of Albert Einstein:
I blurred it by applying a Gaussian blur of radius 12:
Looks a bit like Marilyn Monroe, doesn't it? This is how beer goggles work. You can get the same effect by squinting at picture 1.
If I try to 'enhance' the image by using unsharp mask with radius 12 strength 1 (not that these values are particularly relevant) I get this:
It looks a bit sharper and contrasty, but she won't be discovering new laws of physics any time soon.
Even though you know exactly how I made picture 2, you cannot recreate image 1 from it, because the file simply does not contain enough accurate information.