Extreme Edge Sharpening


This edge-sharpening technique is great when you want to apply some intense sharpening to a particular object in your photo, but there are other areas that you won't want sharpened at all. This technique is different because you're going to actually enhance the edge areas yourself, by using some tricks to put a selection around only those edges that you want to sharpen.

Step One

Open the RGB photo to which you want to apply edge sharpening (in this example, I want to sharpen the prominent fence, but I don't want to sharpen the soft background). Press Command-A (PC: Control-A) to put a selection around the entire photo, then press Command-C (PC: Control-C) to copy the photo into memory.

Step Two

Go to the Channels palette (found under the Window menu) and click on the Create New Channel icon at the bottom of the palette. When the new channel appears, press Command-V (PC: Control-V) to paste a grayscale version of your photo into this new channel. Now, deselect by pressing Command-D (PC: Control-D).

Step Three

Go under the Filter menu, under Stylize, and choose Find Edges. There's no dialog, no settings to enterthe filter is simply applied and it accentuates any visible edges in your photo. The problem you'll likely encounter is that it accentuates too many edges, so you'll want to tweak things a bit so only the most defined edges remain visible.

Step Four

Press Command-L (PC: Control-L) to bring up Levels. When the dialog appears, drag the top-right Input Levels slider (the highlights) to the left. As you do, you'll be "cleaning up" the excess linesthe lines that aren't very well defined and don't need to be sharpened. When the edges look cleaner, click OK. Defining the edge areas within your photo is very important for this method of sharpening to be effective, so we're going to further define those edges.

Step Five

It's going to sound kind of counterproductive, but you're going to blur the existing lines (don't worry, you'll remove the blur in the next step). Go under the Filter menu, under Blur, and choose Gaussian Blur. Enter a Radius setting of 1 pixel and click OK to slightly blur your channel.

Step Six

Press Command-L (PC: Control-L) to bring up the Levels dialog again. This time, you're going to use Levels to remove the blurring, and by doing so, further accentuate the edges. All you have to do is drag the Input Levels sliders at each end (the left shadow slider and the right highlight slider) toward the middle until the blurring is gone. You'll drag them until they almost meet the center midtones slider, or until the blurring is gone and the lines look much more defined. When it looks good to you, click OK.

Step Seven

Go to the Channels palette, press-and-hold the Command key (PC: Control key), and click on the thumbnail for the Alpha 1 channel to load it as a selection.

Step Eight

In the Channels palette, click on the RGB channel to see your full-color image. Your selection is loaded, but it has selected everything but the edges, so you'll need to go under the Select menu and choose Inverse to invert the selection (so that only the well-defined edges in the photo are selected). Before you apply your Unsharp Mask, press Command-H (PC: Control-H) to hide the selection border, so you can really see the results of your sharpening as you apply it. Now, go to the Filter menu, under Sharpen, and apply the Unsharp Mask filter. Move the Amount slider to the right, and when you do, only the selected edge areas will be affected, leaving the trees in the background virtually unsharpened. Press Command-D (PC: Control-D) to deselect, completing the sharpening.

Before

After



    The Photoshop CS2 Book(c) for Digital Photographers
    The Photoshop CS2 Book for Digital Photographers (Voices That Matter)
    ISBN: B002DMJUBS
    EAN: N/A
    Year: 2006
    Pages: 187
    Authors: Scott Kelby

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