Unsharp Mask
The Unsharp Mask command is used to find the areas in an image where substantial color transitions occur, and to sharpen them. The command can be used to adjust the contrast of a specific edge detail and produce light and dark lines from both sides of an edge to emphasize it and create an illusion of a sharper image.
The Unsharp Mask dialog starts by clicking on "Effects -> Unsharp Mask" on the user menu.
