Photoshop 6 for Windows Bible- P17

Photoshop 6 for Windows Bible- P17:If you are reading this foreword, it probably means that you’ve purchased a copyof Adobe Photoshop 6.0, and for that I and the rest of the Photoshop team atAdobe thank you.If you own a previous edition of the Photoshop Bible, you probably know what toexpect. If not, then get ready for an interesting trip.
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Photoshop 6 for Windows Bible- P17 Chapter 10 ✦ Corrective Filtering 449 Soft Sharpened, Threshold: 20 Sharpened, Threshold: 0Figure 10-14: The original Ike is a bit soft (left), a condition I can remedy withUnsharp Mask. Leaving the Threshold value set to 0 brings out the film grain(middle), but raising the value results in equally unattractive artifacts (right).While we wait for Photoshop to give us a better Threshold — one with a Fuzzinessslider or similar control — you can create a better Threshold using a very simplemasking technique. Using a few filters that I explore at greater length throughoutthis chapter and the next, you can devise a selection outline that traces the essen-tial edges in the image — complete with fuzzy transitions — and leaves the non-edges unmolested. So get out your favorite old vintage photograph and followalong with these steps. STEPS: Creating and Using an Edge Mask 1. Duplicate one of the color channels. Bring up the Channels palette and drag one of the color channels onto the little page icon. Ike is a grayscale image, so I duplicate the one and only channel. 2. Choose Filter ➪ Stylize ➪ Find Edges. As I explain in Chapter 11, the Find Edges filter automatically traces the edges of your image with thick, gooey outlines that are ideal for creating edge masks. 3. Press Ctrl+I. Or choose Image ➪ Adjust ➪ Invert. Find Edges produces black lines against a white background, but in order to select your edges, you need white lines against a black background. The Invert command reverses the lights and darks in the mask, as in the first example in Figure 10-15.450 Part III ✦ Selections, Masks, and Filters Find Edges, Invert Sharpened edges Find edge mask Figure 10-15: I copy a channel, find the edges, and invert (left). I then apply a string of filters to expand and soften the edges (middle). After converting the mask to a selection outline, I reapply Unsharp Mask with winning results (right). 4. Choose Filter ➪ Noise ➪ Median. You need fat, gooey edges, and the current ones are a bit tenuous. To firm up the edges, choose the Median filter, enter a value of 2 (or thereabouts), and press Enter. 5. Choose Filter ➪ Other ➪ Maximum. The next step is to thicken up the edges. The Maximum filter expands the white areas in the image, serving much the same function in a mask as Select ➪ Modify ➪ Expand serves when editing a selection outline. Enter 4 for the Radius value and press Enter. 6. Choose Filter ➪ Blur ➪ Gaussian Blur. Unfortunately, the Maximum filter results in a bunch of little squares that don’t do much for our cause. You can merge the squares into a seamless line by choosing the Gaussian Blur command and entering 4, the same radius you entered for Maximum. Then press Enter. The completed mask is pictured in the second example of Figure 10-15. Though hardly an impressive sight to the uninitiated eye, you’re looking at the perfect edge mask — soft, natural, and extremely accurate. 7. Return to the standard composite view. Press Ctrl+tilde (~) in a color image. In a grayscale image, press Ctrl+1. 8. Convert the mask to a selection outline. Ctrl-click the mask name in the Channels palette. Photoshop selects the most essential edges in the image without selecting the grain. Chapter 10 ✦ Corrective Filtering 451 9. Choose Filter ➪ Sharpen ➪ Unsharp Mask. In the last example in Figure 10-15, I applied the highest permitted Amount value, 500 percent, and a Radius of 2.0. 10. Whatever values you use, make sure the Threshold is set to 0. And always leave it at 0 from this day forward.In case Figures 10-14 and 10-15 are a little too subtle, I include enlarged views ofthe great general’s eyes in Figure 10-16. The top eyes show the result of using theThreshold value, the bottom eyes were created using the edge mask. Which onesappear sharper and less grainy to you? Figure 10-16: Enlarged views of the last examples from Figures 10-14 (top) and 10-15 (bottom). ...