Difference between Unsharp Mask and normal Sharpener

[titlis]

And actually, I wonder what 'Unsharp Mask' stands for :confused:

[Gavino]

http://en.wikipedia.org/wiki/Unsharp_masking

[Guest]

See here to understand that "unsharp masking" is just a convolution kernel:

http://forum.doom9.org/showthread.php?t=51988

The strange phrase "unsharp mask" derives from the analog photographic domain; it originated before computers.

[titlis]

thanks now it's clear

so basically It behaves like a normal sharpener but functions in different method comparing original one and blurred one?
ooops now I understand why they call it 'unsharp'....
would better search wiki before asking... my bad