In the Preview box that pops up there is a slider to adjust the radius of the pixels. Slide this from left to right until the edges of the image to stand out, almost in Bass Relief. Click Ok, - the image will look as though it has been “Greyed Out” – but don’t be alarmed.
In the Layers palette (where it says Normal in the tab box at the top), click on the down arrow to the right of this box and select either Soft Light or Overlay – Hey presto! Your image has reappeared and looks sharper

Now, magnify a section of the image (often of a sharp, contrasty edge) and, in the Layers palette, slide the Opacity scale to the left to reduce the effect until it softens the edge between the areas of high contrast.

When you are happy, flatten the layers and save in the usual way.

Ray Anderson.