Photoshop 6 for Windows Bible- P19

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Photoshop 6 for Windows Bible- P19:If you are reading this foreword, it probably means that you’ve purchased a copy of Adobe Photoshop 6.0, and for that I and the rest of the Photoshop team at Adobe thank you. If you own a previous edition of the Photoshop Bible, you probably know what to expect. If not, then get ready for an interesting trip.

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Nội dung Text: Photoshop 6 for Windows Bible- P19

Chapter 11 ✦ Full-Court Filtering 509 Tip Both filters can affect elliptical regions only. If a selection outline is not elliptical, Photoshop applies the filter to the largest ellipse that fits inside the selection. As a result, the filter may leave behind a noticeable elliptical boundary between the affected and unaffected portions of the selection. To avoid this effect, select the region you want to edit with the elliptical marquee tool and then feather the selec- tion before filtering it. This softens the effect of the filter and provides a more grad- ual transition (even more so than Pinch already affords). One of the more remarkable properties of the Pinch filter is that it lets you turn any image into a conical gradation. Figure 11-15 illustrates how the process works. First, blur the image to eliminate any harsh edges between color transitions. Then apply the Pinch filter at full strength (100 percent). Reapply the filter several more times. Each time you press Ctrl+F, the center portion of the image recedes farther and far- ther into the distance, as shown in Figure 11-15. After 10 repetitions, the face in the example all but disappeared. Original Gaussian blur, 5.0 Pinch, 100% Pinch x 3 Pinch x 5 Pinch x 10, Radial Blur Figure 11-15: After applying the Gaussian Blur filter, I pinched the image 10 times and applied the Radial Blur filter to create a conical gradation. Next, apply the Radial Blur filter set to Spin 10 pixels or so to mix the color bound- aries a bit. The result is a type of gradation that you can’t create using Photoshop’s gradient tool.
510 Part III ✦ Selections, Masks, and Filters Twirling spirals The Twirl filter rotates the center of a selection while leaving the sides fixed in place. The result is a spiral of colors that looks for all the world as if you poured the image into a blender set to a very slow speed. When you choose Filter ➪ Distort ➪ Twirl, Photoshop displays the Twirl dialog box, shown in Figure 11-16. Enter a positive value from 1 to 999 degrees to spiral the image in a clockwise direction. Enter a negative value to spiral the image in a coun- terclockwise direction. As you are probably already aware, 360 degrees make a full circle, so the maximum 999-degree value equates to a spiral that circles around almost three times, as shown in the bottom-right example in Figure 11-17. Figure 11-16: The Twirl dialog box enables you to create spiraling images. Tip The Twirl filter produces smoother effects when you use lower Angle values. Therefore, you’re better off applying a 100-degree spiral 10 times rather than applying a 999-degree spiral once, as you can see in Figure 11-17.
Chapter 11 ✦ Full-Court Filtering 511 Original Twirl, 100° Twirl, 100° x 3 Twirl, 100° x 5 Twirl, 100° x 10 Twirl, 999° Figure 11-17: The effects of applying the Twirl filter. Repeatedly applying the Twirl filter at a moderate value (bottom middle) produces a smoother effect than applying the filter once at a high value (bottom right). In addition to creating ice-cream swirls like those shown in Figure 11-17, you can use the Twirl filter to create organic images virtually from scratch, as witnessed by Figures 11-18 and 11-19. To create the images shown in Figure 11-18, I used the Spherize filter to flex the conical gradation vertically by entering 100 percent in the Amount option box and selecting Vertical Only from the Mode pop-up menu. After repeating this filter sev- eral times, I eventually achieved a stalactite-stalagmite effect, as shown in the cen- ter example of the figure. I then repeatedly applied the Twirl filter to curl the flexed gradations like two symmetrical hairs. The result merges the simplicity of pure math with the beauty of bitmapped imagery. Figure 11-19 illustrates a droplet technique designed by Mark Collen. I took the liberty of breaking down the technique into the following steps.
512 Part III ✦ Selections, Masks, and Filters Figure 11-18: You can create surprisingly naturalistic effects using distortion filters exclusively. Original Spherize, 100%, Vertical Spherize x 3 Spherize x 5 Spherize x 7 Twirl, 100° Twirl x 3 Twirl x 5 Twirl x 10 Figure 11-19: Although they appear as if they might be the result of the ZigZag filter, these images were created entirely by using the gradient tool, the Twirl filter, and a couple of transformations.
Chapter 11 ✦ Full-Court Filtering 513 STEPS: Creating a Thick-Liquid Droplet 1. Press D to restore the default foreground and background colors. 2. Shift-drag with the rectangular marquee tool to select a square portion of an image. 3. Create a linear gradation by dragging inside the selection outline with the gradient tool. Before you drag, select the linear gradient style on the Options bar and select the foreground to background gradient from the Gradients drop-down palette, also on the Options bar. Drag a short distance near the center of the selection from upper left to lower right, creating the gradation shown in the top-left box in Figure 11-19. 4. Choose the Twirl filter and apply it at –360 degrees so that the spiral moves counterclockwise. To create the top-right image in the figure, I applied the Twirl filter three times. Each repetition of the filter adds another ring of ripples. 5. Press Ctrl+J to copy the selection to a layer. 6. Choose Edit ➪ Transform ➪ Flip Horizontal. 7. Lower the Opacity value to 50 percent. You can do this from the keyboard by selecting the rectangular marquee tool and pressing 5. The result appears in the lower-left example in Figure 11-19. 8. Choose Edit ➪ Transform ➪ Rotate 90° CW. This rotates the layer a quarter turn, thus creating the last image in the figure. You can achieve other interest- ing effects by choosing Lighten, Darken, and others from the brush modes pop-up menu. Now, if a few twirls and transformations can produce an effect this entertaining in black and white, just imagine what you can do in color. On second thought, don’t imagine; check out Color Plate 11-6 instead. The first row in this eight-part color plate is nothing more than a color version of Figure 11-19, intended merely to set the scene. As you can see, I’ve created a gradation using two complementary colors, blue and yellow. In the fifth example (lower left), I apply the Difference blend mode to the layer (Shift+Alt+E with a non-painting tool selected) and return the Opacity setting to 100 percent. Next, I clone that layer and rotate it another 90 degrees clock- wise to produce the sixth example. The Difference blend mode remains in effect for this cloned layer as well. Not satisfied, I clone that layer, rotate it another 90 degrees, and flip it horizontally. The result, also subject to Difference, is the seventh example. Then for the coup de grâce, I randomly apply the Twirl, Spherize, and ZigZag filters to the layers to mutate the concentric rings into something a little more interesting. If that went a little fast for you, not to worry. More important than the specific effects is this general category of distortion drawings. A filter such as Pinch or Twirl permits you to create wild imagery without ever drawing a brushstroke or scanning a photograph. If you can do this much with a simple two-color gradation, just think of what you can do if you throw in a few more colors. Pixels are little more than fodder for these very powerful functions.
514 Part III ✦ Selections, Masks, and Filters Creating concentric pond ripples I don’t know about you, but when I think of zigzags, I think of cartoon lightning bolts, wriggling snakes, scribbles — anything that alternately changes directions along an axis, like the letter Z. The ZigZag filter does arrange colors into zigzag pat- terns, but it does so in a radial fashion, meaning that the zigzags emanate from the center of the image like spokes in a wheel. The result is a series of concentric rip- ples. If you want parallel zigzags, check out the Ripple and Wave filters, described in the next section. (The ZigZag filter creates ripples and the Ripple filter creates zigzags. Go figure.) When you choose Filter ➪ Distort ➪ ZigZag, Photoshop displays the ZigZag dialog box, shown in Figure 11-20. The dialog box offers the following options: ✦ Amount: Enter an amount between negative and positive 100 in whole-number increments to specify the depth of the ripples. If you enter a negative value, the ripples descend below the surface. If you enter a positive value, the ripples protrude upward. Examples of three representative Amount values appear in Figure 11-21. Figure 11-20: The ZigZag dialog box lets you add concentric ripples to an image, as if the image were reflected in a pond into which you dropped a pebble.
Chapter 11 ✦ Full-Court Filtering 515 Pond Ripples Amount = 10 50 100 Out From Center Amount = 10 50 100 Around Center Amount = 10 50 100 Figure 11-21: The effects of the ZigZag filter subject to three Amount values and the Pond Ripples, Out From Center, and Around Center settings. In all cases, the Ridges value was 5. ✦ Ridges: This option box controls the number of ripples in the selected area and accepts any value from 1 to 20. Figure 11-22 demonstrates the effect of three Ridges values. ✦ Pond Ripples: This option is really a cross between the two that follow. It moves pixels outward and rotates them around the center of the selection to create circular patterns. As demonstrated in the top rows of Figures 11-21 and 11-22, this option truly results in a pond ripple effect.
516 Part III ✦ Selections, Masks, and Filters Pond Ripples Ridges = 5 10 20 Out From Center Ridges = 5 10 20 Around Center Ridges = 5 10 20 Figure 11-22: The effects of the ZigZag filter using three Ridges values and each of the three Style pop-up menu settings. In all cases, the Amount value was 20. ✦ Out From Center: When you select this option, Photoshop moves pixels outward in rhythmic bursts according to the value in the Ridges option box. Because the gradation image I created in Figure 11-15 was already arranged in a radial pattern, I brought in Moses to demonstrate the effect of the Out From Center option, as shown in the second rows of Figures 11-21 and 11-22. ✦ Around Center: Select this option to rotate pixels in alternating directions around the circle without moving them outward. This is the only option that produces what I would term a zigzag effect. The last rows of Figures 11-21 and 11-22 show the effects of the Around Center option.
Chapter 11 ✦ Full-Court Filtering 517 Creating parallel ripples and waves Photoshop provides four means to distort an image in parallel waves, as if the image were lying on the bottom of a shimmering or undulating pool. Of the four, the ripple filters — which include Ripple, Ocean Ripple, and Glass — are only moder- ately sophisticated, but they’re also relatively easy to apply. The fourth filter, Wave, affords you greater control, but its options are among the most complex Photoshop has to offer. The Ripple filter To use the Ripple filter, choose Filter ➪ Distort ➪ Ripple. Photoshop displays the Ripple dialog box shown in Figure 11-23. You have the following options: ✦ Amount: Enter an amount between negative and positive 999 in whole-number increments to specify the width of the ripples from side to side. Negative and positive values change the direction of the ripples, but visually speaking, they produce identical effects. The ripples are measured as a ratio of the Size value and the dimensions of the selection — all of which translates to, “Experiment and see what happens.” You can count on getting ragged effects from any value over 300, as illustrated in Figure 11-24. Figure 11-23: The Ripple filter makes an image appear as if it were refracted through flowing water. ✦ Size: Select one of the three options in the Size drop-down menu to change the length of the ripples. The Small option results in the shortest ripples and therefore the most ripples. As shown in the upper-right corner of Figure 11-24, combining the Small option with a high Amount value results in a textured- glass effect. The Large option results in the longest and fewest ripples.
518 Part III ✦ Selections, Masks, and Filters Small, 100 300 999 Medium, 100 300 999 Large, 100 300 999 Figure 11-24: The effects of combining three different Ripple filter Amount values with three different Size settings. Tip You can create a blistered effect by overlaying a negative ripple onto a posi- tive ripple. Try this: First, copy the selection. Then apply the Ripple filter with a positive Amount value — say, 300. Next, paste the copied selection and apply the Ripple filter at the exact opposite Amount value, in this case, –300. Press 5 to change the Opacity value to 50 percent. The result is a series of dia- metrically opposed ripples that cross each other to create teardrop blisters.
Chapter 11 ✦ Full-Court Filtering 519 Ocean Ripple and Glass The Ocean Ripple and Glass filters are gifts from Gallery Effects. Both filters emu- late the effect of looking at an image through textured glass. These two distorters so closely resemble each other that they would be better merged into one. But where the effects filters are concerned, interface design is as fickle and transitory as the face on the cover of Tiger Beat Magazine. The Ocean Ripple and Glass dialog boxes appear joined at the hip in Figure 11-25. While the names and effects of the specific slider bars vary, the only real difference between the two filters is that Ocean Ripple subscribes to a fixed ripple texture, and Glass lets you switch out the texture by selecting from a pop-up menu. Figure 11-25: The Ocean Ripple and Glass effects filters are two birds of a feather, ultimately born from the same egg. To guide you in your experimentations, Figure 11-26 shows the Pinch gradation sub- ject to several Ocean Ripple settings. The first number represents the Ripple Size value (listed first in the dialog box); the second number in the figure represents the Ripple Magnitude value. As you can see, you can vary the Size value with impunity. But raise the Magnitude value, and you’re looking through sculpted glass.
520 Part III ✦ Selections, Masks, and Filters 3, 5 8, 5 15, 5 3, 20 8, 20 15, 20 Figure 11-26: Raising the Ripple Size value (first number in each pair) spreads out the effect; raising the Ripple Magnitude (second number) adds more depth and contrast to the ripples. The Wave filter Now that you’ve met the ripple family, it’s time to ride the Wave. I’ve come to love this filter — I use it all the time — but it’s complex enough to warrant its own book. It wouldn’t be a very big book and no one would buy it, but you never know what a freelancer like me will do next. Keep an eye out for Wave Filter Bible at your local bookstore. In the meantime, choose Filter ➪ Distort ➪ Wave (that’s the easy part) to display the Wave dialog box shown in Figure 11-27. Photoshop presents you with the following options, which make applying a distortion every bit as easy as operating an oscillo- scope: ✦ Number of Generators: Right off the bat, the Wave dialog box boggles the brain. A friend of mine likened this option to the number of rocks you throw in the water to start it rippling. One generator means that you throw in one rock to create one set of waves, as demonstrated in Figure 11-28. You can throw in
Chapter 11 ✦ Full-Court Filtering 521 two rocks to create two sets of waves (see Figure 11-29), three rocks to create three sets of waves, and all the way up to a quarryful of 999 rocks to create, well, you get the idea. If you enter a high value, however, be prepared to wait a few years for the preview to update. If you can’t wait, press Escape, which turns off the preview until the next time you enter a value in the dialog box. Figure 11-27: The Wave dialog box lets you wreak scientific havoc on an image. Put on your pocket protector, take out your slide rule, and give it a whirl. ✦ Wavelength and Amplitude: Beginning to feel like you’re playing with a ham radio? The Wave filter produces random results by varying the number and length of waves (Wavelength) as well as the height of the waves (Amplitude) between minimum and maximum values, which can range from 1 to 999. (The Wavelength and Amplitude options, therefore, correspond in theory to the Size and Amount options in the Ripple dialog box.) Figures 11-28 and 11-29 show examples of representative Wavelength and Amplitude values. ✦ Scale: You can scale the effects of the Wave filter between 1 and 100 percent horizontally and vertically. All the effects featured in Figures 11-28 and 11-29 were created by setting both Scale options to 15 percent.
522 Part III ✦ Selections, Masks, and Filters Sine 20, 50 50, 100 100, 200 Triangle 20, 50 50, 100 100, 200 Square 20, 50 50, 100 100, 200 Figure 11-28: The effect of three sets of Maximum Wavelength (first value) and Amplitude (second value) settings when combined with each of the three Type settings. The Number of Generators value was 1 in all cases. ✦ Type: You can select from three kinds of waves. The Sine option produces standard sine waves that rise and fall smoothly in bell-shaped curves, just like real waves. The Triangle option creates zigzags that rise and fall in straight lines, like the edge of a piece of fabric cut with pinking shears. The Square option has nothing to do with waves at all, but rather organizes an image into a series of rectangular groupings, reminiscent of Cubism. You might think of this option as an extension of the Mosaic filter. Figures 11-28 and 11-29 demon- strate all three options.
Chapter 11 ✦ Full-Court Filtering 523 Sine 20, 50 50, 100 100, 200 Triangle 20, 50 50, 100 100, 200 Square 20, 50 50, 100 100, 200 Figure 11-29: The only difference between these images and their counterparts in Figure 11-28 is that the Number of Generators value used for all images was 2. ✦ Randomize: The Wave filter is random by nature. If you don’t like the effect you see in the preview box, click the Randomize button to stir things up a bit. You can keep clicking the button until you get an effect you like. ✦ Undefined Areas: The Wave filter distorts a selection to the extent that gaps may appear around the edges. You can fill those gaps either by repeating pix- els along the edge of the selection, as in the figures, or by wrapping pixels from the left side of the selection onto the right side and pixels from the top edge of the selection onto the bottom.
524 Part III ✦ Selections, Masks, and Filters Distorting an image along a curve The Distort command, which isn’t discussed elsewhere in this book, creates four corner handles around an image. You drag each corner handle to distort the selected image in that direction. Unfortunately, you can’t add other points around the edges to create additional distortions, which can be frustrating if you’re trying to achieve a specific effect. If you can’t achieve a certain kind of distortion using Edit ➪ Free Transform, the Shear filter may be your answer. Shear distorts an image along a path. When you choose Filter ➪ Distort ➪ Shear, you get the dialog box shown in Figure 11-30. Initially, a single line that has two points at either end appears in the grid at the top of the box. When you drag the points, you slant the image in the preview. This, plus the fact that the filter is named Shear — Adobe’s strange term for skewing (it appears in Illustrator as well) — leads many users to dismiss the filter as nothing more than a slanting tool. But in truth, it’s more versatile than that. Figure 11-30: Click the grid line in the left corner of the Shear dialog box to add points to the line. Drag these points to distort the image along the curve. You can add points to the grid line simply by clicking on it. A point springs up every time you click an empty space in the line. Drag the point to change the curvature of the line and distort the image along the new curve. To delete a point, drag it off the left or right side of the grid. To delete all points and return the line to its original vertical orientation, click the Defaults button.
Chapter 11 ✦ Full-Court Filtering 525 The Undefined Areas options work just as they do in the Wave dialog box (described in the preceding section). You can either fill the gaps on one side of the image with pixels shoved off the opposite side by selecting Wrap Around or repeat pixels along the edge of the selection by selecting Repeat Edge Pixels. Changing to polar coordinates The Polar Coordinates filter is another one of those gems that a lot of folks shy away from because it doesn’t make much sense at first glance. When you choose Filter ➪ Distort ➪ Polar Coordinates, Photoshop presents two radio buttons, as shown in Figure 11-31. You can either map an image from rectangular to polar coordinates or from polar to rectangular coordinates. Figure 11-31: In effect, the Polar Coordinates dialog box enables you to map an image onto a globe and view the globe from above. All right, time for some global theory. The first image in Figure 11-32 shows a stretched detail of the world map from the Digital Stock library. This map falls under the heading of a Mercator projection, meaning that Greenland is all stretched out of proportion, looking as big as the United States and Mexico combined. The reason for this has to do with the way different mapping systems handle longi- tude and latitude lines. On a spherical globe, lines of latitude converge at the poles. On a Mercator map, they run absolutely parallel. Because the Mercator map exag- gerates the distance between longitude lines as you progress away from the equa- tor, it likewise exaggerates the distance between lines of latitude. The result is a map that becomes infinitely enormous at each of the poles.
526 Part III ✦ Selections, Masks, and Filters Figure 11-32: The world from the equator up expressed in rectangular (top) and polar (bottom) coordinates. When you convert the map to polar coordinates (by selecting the Rectangular to Polar radio button in the Polar Coordinates dialog box), you look down on it from the extreme North or South Pole. This means that the entire length of the top edge of the Mercator map becomes a single dot in the exact center of the polar projec- tion. The length of the bottom edge of the map wraps around the entire perimeter of the circle. The second example in Figure 11-32 shows the result. As you can see, the Rectangular to Polar option is just the tool for wrapping text around a circle.
Chapter 11 ✦ Full-Court Filtering 527 If you select the Polar to Rectangular option, the Polar Coordinates filter produces the opposite effect. Imagine for a moment that the conical gradation shown in the upper-left corner of Figure 11-33 is a fan spread out into a full circle. Now imagine closing the fan, breaking the hinge at the top, and spreading out the rectangular fab- ric of the fan. The center of the fan unfolds to form the top edge of the fabric, and what was once the perimeter of the circle is now the bottom edge of the fabric. Figure 11-33 shows two examples of what happens when you convert circular images from polar to rectangular coordinates. Figure 11-33: Two familiar circular images (left) converted from polar to rectangular coordinates (right). The top example is simple enough that you can probably predict the results of the conversion in your head. The lower example looks cool, but you’d need a brain extension to predict the outcome. Tip The Polar Coordinates filter is a great way to edit gradations. After drawing a linear gradation with the gradient tool (as discussed in Chapter 6), try applying Filter ➪ Distort ➪ Polar Coordinates with the Polar to Rectangular option selected. (Rectan- gular to Polar just turns it into a radial gradation, sometimes with undesirable results.) You get a redrawn gradation with highlights at the bottom of the selection. Press Ctrl+F to reapply the filter to achieve another effect. You can keep repeating this technique until jagged edges start to appear. Then press Ctrl+Z to go back to the last smooth effect.
528 Part III ✦ Selections, Masks, and Filters Distorting an image inside out The following exercise describes how to achieve a sizzling Parting of the Red Sea effect. Although it incorporates several distortion filters, the star of the effect is the Polar Coordinates filter, which is used to turn the image inside out and then convert it back to polar coordinates after flipping it upside down. No scanned image or artistic talent is required. Rumor has it that Moses puts in a guest appearance in the final image. This effect is the brainchild of Mark Collen, easily the most imaginative distortion expert I’ve had the pleasure of knowing. I already mentioned his name in this chap- ter, in connection with the steps for “Creating a Thick-Liquid Droplet.” To be per- fectly honest, I probably should have mentioned him more than that because many of the ideas in this chapter were based on long, expensive telephone conversations with the guy. At any rate, Figures 11-34 through 11-39 show the progression of the image through the following steps, starting with a simplistic throwback to Dada (the art move- ment, not the family member) and continuing to the fabled sea rising in billowing streams. Color Plate 11-7 shows one of Mark’s most vivid images, which was cre- ated in part using many of the techniques from the following steps. Obviously, Mark used a couple of other filtering and nonfiltering techniques to create his image, but gee whiz folks, you can’t expect the guy to share everything he knows in one fell swoop. He has to make a living, after all. STEPS: The Parting of the Red Sea Effect 1. Draw some random shapes in whatever colors you like. My shapes appear against a black background in Figure 11-34, but you can use any shapes and colors you like. To create each shape, I used the lasso tool to draw the outline of the shape and pressed Alt+Backspace to fill the lassoed selection with the foreground color. The effect works best if your colors have a lot of contrast. Figure 11-34: Draw several meaningless shapes with the lasso tool and fill each with a different color.