I was wondering, what is the difference between the high-pass filter and the unsharpen mask one?
I am used to use the first to improve the quality of the image (to make it less dreamy and more realistic, especially when doing photomanipulations). I tired using also the second one, but the only thing I have noticed is that in this way I have to work with more paramenters, but the result at the end will be the same (using the correct set of parameters), am I right?
As I wrote on the comment, unsharp filter combines a blurry (unsharp) version of the image with the original, creating an apparently sharper version. High Pass filter is an algorithm which passes the high-frequency detail while blocking the low frequency areas. When applied to a copied layer of the image it results in an image of middle gray, lighter and darker areas along the high frequency edges. The blend mode of this layer is changed to one of Overlay or Soft Light to apply the crispness to the original. Unsharp mask increases the contrast along the edges by making light side lighter and dark side darker.
Whereas in High Pass filter, there is only one parameter, radius, in the Unsharp Mask there are three, radius, amount, and threshold. The first one determines the number pixels along the edge to apply the contrast enhancement, the amount determines how much to increase the contrast, and threshold controls how different the tones along an edge has to be for the filter to apply.
Some images and approaches may benefit from high pass filter, but is it generally augmented by an application of some kind of unsharp filter for the output purpose, print or screen. This is a very long subject. If you care to read more, follow the link below:
Source : Link , Question Author : Rhei , Answer Author : Community