Adobe Photoshop CS4 - Manual (Page 224)

217 USING PHOTOSHOP CS4
Retouching and transforming
Last updated 1/10/2010
• Choose Image > Adjustments > Invert to invert the image.
Find Edges filter applied and image inverted
• With the inverted image still selected, choose Filter > Other > Maximum. Set the radius to a low number and
click OK to thicken the edges and randomize the pixels.
• Choose Filter > Noise > Median. Set the radius to a low number and click OK. This averages the neighboring pixels.
• Choose Image > Adjustment > Levels and set the black point high to get rid of random pixels. If necessary, you can
also paint with black to retouch the final edge mask.
Setting the black point high in Levels to eliminate random pixels in the edge mask
• Choose Filter > Blur > Gaussian Blur to feather the edges.
Important: The Maximum, the Median, and the Gaussian Blur filters soften the edge mask so that the sharpening effects
blend better in the final image. Although all three filters are used in this procedure, you can experiment using only one or two.
2 In the Channels panel, Ctrl-click (Windows) or Command-click (Mac OS) the duplicate channel to make the edge
mask a selection.
3 In the Layers panel, select the image layer. Make sure the selection is still visible on the image.
4 Choose Select > Inverse.
5 With the selection active on the image layer, choose Filter > Sharpen > Unsharp Mask. Set the desired options and
click OK.
To view your results, select the RGB channel in the Channels panel and deselect the selection in the image.
You can create an action to conveniently apply all the steps in the procedure.
Add lens blur
Adds blur to an image to give the effect of a narrower depth of field so that some objects in the image stay in focus and
others areas are blurred. You can use a simple selection to determine which areas are blurred, or you can provide a
separate alpha channel depth map to describe exactly how you want the blur added.