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Photoshop CS Bible @Team LiB - Stacy C.

Stacy C. Photoshop CS Bible @Team LiB - Wiley Publishing, 2004. - 773 p.
Download (direct link): photoshopcsbible2004.pdf
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I applied Unsharp Maskwith an Amount of500 percent, a Radius of4.0 pixels, and a Threshold of0. T
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he result is an exaggerated sharpening effect with very thick edges, creating the appearance ofdeep g rooves in the cream on the woman's face (upper right). The remaining examples show what happens if I alternatively apply these same settings to a single color channel or a pair of channels. The results are relatively predictable once you understand what's going on. Unsharp Mask highlights edges by tracing light and dark lines along them. If you apply the filter in just the red channel, for example, the edges be come red where Unsharp Mask traces its light lines and turquoise (the inverse of red) where the lines a re dark. Beyond special effects, you can apply Unsharp Maskto independent channels to accommodat e an image that has different focus problems in each channel (see Color Plate 10-3).Color Plate 102: The Gaussian Blur filter ranks among Photoshop's most useful functions, essential for building mas ks, creating depth effects, and more. In the examples on left, I used Gaussian Blurto simulate a soft di ffused glow. The first image shows the result ofapplying the filterwith a Radius of12 pixels. The imag e appears out of focus, as if in the background. The problem is, this woman is our foreground subject, so she needs to look sharp and clear. To bring back some ofthe detail, I chose Edit ® Fade and set th e Mode to Darken, which kept only those pixels from the blur effect that were darkerthan their counter parts in the original image (middle). The result is an overall darkening ofthe image, with blurrytransitio ns most evident in the highlights like the cheeks, eyes, and teeth. To restore some ofthe lightness to t he image, I pressed Ctrl+F (z -
F) to reapply the Gaussian Blur filter using the same Radius setting. Then I again chose Edit ® Fade, t his time changing the Mode to Linear Dodge and reducing the Opacity value to 80 percent. The effect i s one of an image shot in soft focus under powerful direct light (bottom), but with the pivotal details in t he image fully intact.Color Plate 103: This image I created for Macworld magazine more than ten years ago illustrates a common proble m with scanned images. Where you see a continuous-
tone image, yourscannersees and captures a collection ofcolored dots. Ifyou commercially reproduc e that scanned image as I've done at top you're adding new halftone to old halftone, which invariably produces moire patterns. How do you get rid ofthe halftone pattern without harming the image? The e asy way is to apply the Dust & Scratches filter. But as demonstrated by the second image, in averaging away the pattern, Dust & Scratches has averaged away the detail in the image as well. The final imag e appears miraculous by comparison, and yet it's the result ofabout 10 minutes ofwork on the original scan. I used three filters Median, Gaussian Blur, and Unsharp Mask each applied to a single color ch annel at a time. As is typical, the blue channel was in the worst shape, so I applied the highest Radius amounts there. I was more careful with the green and red channels, which carry the majority ofthe det ail and color information, respectively. For a full account ofthe procedure, read "Cleaning up scanned halftones" nearthe end ofChapter 10.ColorPlate 111: Most of Photoshop's Sketch filters those that appear under the Filter ® Sketch submenu recolor an image entirely in the foreground and background colors. (The exceptions are Chrome, which converts the image to shades ofgray, and Water Paper, which retains the image's original colors.) For example, starting with the photograph shown at top, I set the foreground and background colors to medium gree n and light turquoise, respectively, and then applied Filter®Sketch ® Halftone Pattern using the settin gs listed in the second image. The result is a photo that looks as if it were projected on an old-style computer monitor. That's fine, but what ifyou want to combine the texture from the filtered image with the colors from the original? Fade the filter. Immediately after applying the Halftone Pattern filter, I pressed Ctrl+Shift+F (z -Shift-
F on the Mac) to invoke the Fade command and changed the blend mode to Overlay. Shown in the thir d image, the result brings backthe reds and yellows inside the leafbut keeps the filtered greens inside the previously gray background. If you'd prefer to forsake all color from the filtered image, set the blend mode to Luminosity, as in the last example.Color Plate 112: Here I've applied Filter® Pixelate ® Mezzotint with the Type option set to Long Strokes to the photo graph featured at the top of Color Plate 11-1. The left-
hand column of images shows the results of applying the filter in each of the three main color modes, RGB, Lab, and CMYK. In each case, Photoshop has changed all pixels in each and every channel to ei ther black orwhite, resulting in some very high-
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