Depends on if you're sharpening for screen, or for print.
Here's the image sharpened for screen:
Here's the technique:
Duplicate the layer
Go to Filter> Sharpen> Unsharp Mask. Use an amount of 280, radius .7 pixels, threshold 0. No, that's not a typo. At this point, the layer will look oversharpened and pixelated.
Go to Image> Calculations and use the following settings:
This will add an alpha channel in the channels palette. Highlight that channel, and apply Filter> Stylize> Find Edges. Invert the channel (Image> Adjustment> Invert) and apply a gaussian blur at 1.5 pixels.
You now have a workable edge mask. Click on the "Load channel as selection" icon at the bottom of the channel pallette, click on the RGB icon at the top of the channels pallette, switch to the layers pallette, and click on the "add layer mask" icon. Boom, edge mask applied.
Most of the pixelation disappears, because we have now confined the sharpening to the edges (more or less). What we're left with is an image that's very sharp. In fact, it's TOO sharp. Notice the visable halos on the wood paneling?
The Unsharp Mask filter applies the most sharpening to the edges with the highest contrast, and the least to the edges with the lowest contrast. This is exactly opposite of what we want. Go to Layer> Layer Style> Blending Options. In the "Blend if:" box at the bottom of the dialog box, apply the following settings (Alt/Option-clicking on the tabs separates them):
You have now gardually blended the sharpening out of the highlights and shadows, leaving the midtones alone.
One last thing. Applying the Unsharp Mask filter can alter the colors of the image at the edges. To counteract this, set the blend mode of the duplicate layer to "luminosity" before flattening the image.
You're done. As always, feel free to ask if you have questions.
-Medley.
by Q21 on Sat May 05, 2007 2:09 am 
