329 Chapter 8 ✦ Selections and Paths Figure 8-6: Note the results of clicking on a pixel with a brightness value of 140 (top row) and a brightness value of 10 (bottom row) with the tolerance set to three different values. Figure 8-7: Because the yellow Sasquatch sign contains almost no blue, it appears most clearly distinguished from its background in the blue channel. So the blue channel is the easiest channel in which to select the sign with the magic wand. Red Green Blue 32 (default) 60 100 330 Part III ✦ Selections, Masks, and Filters Here’s one more twist to the Tolerance story: The magic wand is affected by the Sample Size option that you select for the eyedropper tool. If you select Point Sample, the wand bases its selection solely on the single pixel that you click. But if you select 3 by 3 Average or 5 by 5 Average, the wand takes into account 15 or 25 pixels, respectively. As you can imagine, this option can have a noticeable impact on the extent of the selection that you get from the wand. Try clicking the same spot in your image using each of these Sample Size settings, using the same Tolerance value throughout, to see what I mean. Making the wand see beyond a single layer The Use All Layers option enables you to create a selection based on pixels from different layers (see Chapter 12 for more about layers). Returning to my previous landmass example, suppose you set Europe on one layer and North America on the layer behind it so the two continents overlap. Normally, if you clicked inside Europe with the magic wand, it would select an area inside Europe without extending out into the area occupied by North America on the other layer. Because the wand doesn’t even see the contents of other layers, anything outside Europe is an empty void. We’re talking pre-Columbus Europe here. If you select Use All Layers, though, the situation changes. Suddenly, the wand can see all the layers you can see. If you click on Europe, and if North America and Europe contain similar colors, the wand selects across both shapes. Mind you, while the Use All Layers option enables the wand to consider pixels on different layers when creating a selection, it does not permit the wand to actually select images on two separate layers. Strange as this may sound, no selection tool can pull off this feat. Every one of the techniques explained in this chapter is appli- cable to only a single layer at a time. Use All Layers merely allows the wand to draw selection outlines that appear to encompass colors on many layers. What good is this? Well, suppose you want to apply an effect to both Europe and North America. With the help of Use All Layers, you can draw a selection outline that encompasses both continents. After you apply the effect to Europe, you can switch to the North America layer — the selection outline remains intact —and then reapply the effect. Ways to Change Selection Outlines If you don’t draw a selection outline correctly the first time, you have two options. You can either draw it again from scratch, which is a real bore, or you can change your botched selection outline, which is likely to be the more efficient solution. Note 331 Chapter 8 ✦ Selections and Paths You can deselect a selection, add to a selection, subtract from a selection, and even select the stuff that’s not selected and deselect the stuff that is. (If this sounds like a load of nonsense, keep reading.) Quick changes Some methods of adjusting a selection outline are automatic: You choose a com- mand and you’re finished. The following list explains how a few commands—all members of the Select menu — work: ✦ Deselect (Ctrl+D): You can deselect the selected portion of an image in three ways. You can select a different portion of the image; click anywhere in the image window with the rectangular marquee tool, the elliptical marquee tool, or the lasso tool; or choose Select ➪ Deselect. Remember, though, when no part of an image is selected, the entire image is susceptible to your changes. If you apply a filter, choose a color-correction command, or use a paint tool, you affect every pixel of the foreground image. ✦ Reselect (Ctrl+Shift+D): If you accidentally deselect an image, you can retrieve the most recent selection outline by choosing Select➪ Reselect. It’s a great func- tion that operates entirely independently of the Undo command and History palette, and it works even after performing a long string of selection-unrelated operations. (You can restore older selections from the History palette, but that usually means undoing operations along the way.) ✦ Inverse (Ctrl+Shift+I): Choose Select ➪ Inverse to reverse the selection. Photoshop deselects the portion of the image that was previously selected and selects the portion of the image that was not selected. This way, you can begin a selection by outlining the portion of the image you want to protect, rather than the portion you want to affect. You can also access the Inverse and Deselect commands from a context-sensitive pop-up menu in the image window. Right-click to make the menu appear under- neath your cursor. Manually adding and subtracting Ready for some riddles? When editing a portrait, how do you select both eyes with- out affecting any other portion of the face? Answer: By drawing one selection and then tacking on a second selection. How do you select a doughnut and leave the hole behind? Answer: Encircle the doughnut with the elliptical marquee tool, and then use the same tool to subtract the center. Tip 332 Part III ✦ Selections, Masks, and Filters Photoshop enables you to whittle away at a selection, add pieces on again, whittle away some more, ad infinitum, until you get it exactly right. Short of sheer laziness or frustration, no reason exists why you can’t eventually create the selection out- line of your dreams: ✦ Adding to a selection outline: To increase the area enclosed in an existing selection outline, Shift-drag with one of the marquee or lasso tools. You also can Shift-click with the magic wand tool or Shift-click with one of the marquee tools when the Fixed Size option is active (as described in the “Geometric selection outlines” section earlier in this chapter). ✦ Subtracting from a selection outline: To take a bite from an existing selection outline, press Alt while using one of the selection tools. ✦ Intersecting one selection outline with another: Another way to subtract from an existing selection outline is to Shift+Alt-drag around the selection with the rectangular marquee, elliptical marquee, or lasso tool. You also can Shift+Alt-click with the magic wand tool. Shift+Alt-dragging instructs Photoshop to retain only the portion of an existing selection that also falls inside the new selection outline. I frequently use this technique to confine a selection within a rectangular or elliptical border. If the key-press techniques seem bothersome, use the selection state buttons at the left end of the Options bar to set your selection tool to add, subtract, or intersect mode. (Figure 8-8 labels the icons.) After clicking a button, simply drag to alter the selection outline. To toggle the tool back to normal operating mode, click the first button in the bunch. Note that the keyboard techniques described in the preceding list work no matter what button you select in the Options bar. For example, if you click the Intersect icon, Alt-dragging still subtracts from the selection outline. Figure 8-8: You can use the selection state buttons as well as the Shift and Alt keys when modifying a selection outline. When you’re working with the magic wand, you can right-click to display a context- sensitive menu that contains the add, subtract, and intersect mode options. Click the mode you want to use. Tip Normal Add IntersectSubtract 6 Photoshop 6 333 Chapter 8 ✦ Selections and Paths Photoshop displays special cursors to help you keep track of a tool’s selection state. Suppose that you select part of an image and the lasso tool is active. When you press Shift or click the Add button on the Options bar, Photoshop appends a little plus sign to the lasso cursor to show you’re about to add. A minus sign indi- cates that you’re set to subtract from the selection outline; a multiply sign appears when you work in intersect mode. If you’re pressing keys to switch tool modes, Photoshop temporarily selects the corresponding selection state button on the Options bar as well. Using Shift and Alt like a pro The roles of the Shift and Alt keys in adding, subtracting, and intersecting selection outlines can interfere with your ability to take advantage of other functions of the selection tools. For example, when no portion of an image is selected, you can Shift- drag with the rectangular marquee tool to draw a square. But after a selection is active, Shift-dragging adds a rectangle— not a square— to the selection outline. This is one reason why Adobe added the selection state buttons to the Options bar. After you click a button, the tool adds, subtracts, or intersects, with no additional key presses on your part, depending on which button you click. But if you want to hide the Options bar or you just prefer pressing keys to clicking buttons, you can control the selection tools from the keyboard without giving up any selection flexibility. The trick is to learn when to press Shift and Alt. Sometimes you have to press the key before you begin your drag; other times you must press the key after you begin the drag but before you release. For example, to add a square to a selection outline, Shift-drag, release Shift while keeping the mouse button pressed, and press Shift again to snap the rectangle to a square. The same goes for adding a circle with the elliptical marquee tool. The following list introduces you to a few other techniques. They sound pretty elaborate, I admit, but with a little practice, they become second nature (so does tightrope walking, but don’t let that worry you). Before you try any of them, be sure to select Normal from the Style pop-up menu on the Options bar. ✦ To subtract a square or a circle from a selection, Alt-drag, release Alt, press Shift, drag until you get it right, release the mouse button, and then release Shift. ✦ To add a rectangle or an ellipse by drawing from the center outward, Shift- drag, release Shift, press Alt, and hold Alt until after you release the mouse button. You can even press the spacebar during the drag to move the mar- quee around, if you like. ✦ To subtract a marquee drawn from the center outward, Alt-drag, release Alt, press Alt again, and hold the key down until after you release. ✦ What about drawing a straight-sided selection with the lasso tool? To add a straight-sided area to an existing selection, Shift-drag with the tool for a short distance. With the mouse button still down, release Shift and press Alt. Then click around as you normally would, while keeping the Alt key down. 6 Photoshop 6 Tip 334 Part III ✦ Selections, Masks, and Filters ✦ To subtract a straight-sided area, Alt-drag with the lasso, release Alt, press Alt again, and click around with the tool. If you can’t manage the last two lasso-tool techniques, switch to the polygonal lasso instead. In fact, the reason Adobe provided the polygonal lasso tool was to accom- modate folks who don’t want to deal with pressing Alt seven times during a single drag (which I strangely quite enjoy). Adding and subtracting by command Photoshop provides several commands under the Select menu that automatically increase or decrease the number of selected pixels in an image according to numer- ical specifications. The commands in the Select ➪ Modify submenu work as follows: ✦ Border: This command selects an area of a specified thickness around the perimeter of the current selection outline and deselects the rest of the selec- tion. For example, to select a 6-point-thick border around the current selec- tion, choose Select ➪ Modify ➪ Border, enter 6 in the Width option box, and press Enter. But what’s the point? After all, if you want to create an outline around a selection, you can accomplish this in fewer steps by choosing Edit➪ Stroke. The Border command, however, broadens your range of options. You can apply a special effect to the border, move the border to a new location, or even create a double-outline effect by first applying Select ➪ Modify ➪ Border and then applying Edit ➪ Stroke. ✦ Smooth: This command rounds off the sharp corners and weird anomalies in the outline of a selection. When you choose Select ➪ Modify ➪ Smooth, the program asks you to enter a Sample Radius value. Photoshop smoothes out corners by drawing little circles around them; the Sample Radius value deter- mines the radius of these circles. Larger values result in smoother corners. The Smooth command is especially useful in combination with the magic wand. After you draw one of those weird, scraggly selection outlines with the wand tool, use Select ➪ Modify ➪ Smooth to smooth out the rough edges. ✦ Expand and Contract: Both of these commands do exactly what they say, either expanding or contracting the selected area by a specified amount. For example, if you want an elliptical selection to grow by 8 pixels, choose Select ➪ Modify ➪ Expand, enter 8, and call it a day. These are extremely useful commands; I refer to them several times throughout the book. Photoshop 6 enables you to expand and contract selections by as many as 100 pixels, up from the previous limit of 16. The upper limits of the Border and Smooth commands were raised also (to 200 and 100 pixels, respectively), but my guess is that you’ll have less reason to take advantage of those changes than you will the new ranges for Expand and Contract. 6 Photoshop 6 Tip 335 Chapter 8 ✦ Selections and Paths Both Expand and Contract have a flattening effect on a selection. To round things off, apply the Smooth command with a Sample Radius value equal to the number you just entered into the Expand Selection or Contract Selection dialog box. You end up with a pretty vague selection outline, but what do you expect from automated commands? In addition to the Expand command, Photoshop provides two other commands— Grow and Similar— that increase the area covered by a selection outline. Both com- mands resemble the magic wand tool because they measure the range of eligible pix- els by way of a Tolerance value. In fact, the commands rely on the same Tolerance value (on the Options bar) that you set for the magic wand. So if you want to adjust the impact of either command, you must first select the magic wand and then apply the commands: ✦ Grow: Choose Select ➪ Grow to select all pixels that both neighbor an existing selection and resemble the colors included in the selection, in accordance with the Tolerance value. In other words, Select ➪ Grow is the command equivalent of the magic wand tool. If you feel constrained because you can only click one pixel at a time with the magic wand tool, you may prefer to select a small group of representative pixels with a marquee tool and then choose Select ➪ Grow to initiate the wand’s magic. ✦ Similar: Another member of the Select menu, Similar works like Grow, except the pixels needn’t be adjacent. When you choose Select ➪ Similar, Photoshop selects any pixel that falls within the tolerance range, regardless of the loca- tion of the pixel in the foreground image. Although both Grow and Similar respect the magic wand’s Tolerance value, they pay no attention to the other wand options — Contiguous, Use All Layers, and Anti- aliased. Grow always selects contiguous regions only; Similar selects noncontigu- ous areas. Neither can see beyond the active layer or produce antialiased selection outlines. One of the best applications for the Similar command is to isolate a complicated image set against a consistent background whose colors are significantly lighter or darker than the image. Consider Figure 8-9, which features a dark and ridiculously complex foreground image set against a continuous background of medium-to-light brightness values. The following steps explain how to separate this image using the Similar command in combination with a few other techniques I’ve described thus far. STEPS: Isolating a Complex Image Set Against a Plain Background 1. Use the rectangular marquee tool to select some representative portions of the background. In Figure 8-9, I selected the lightest and darkest portions of the background along with some representative shades in between. Remember, you make multiple selections by Shift-dragging with the tool. Note Tip 336 Part III ✦ Selections, Masks, and Filters Figure 8-9: Before choosing Select➪ Similar, select a few sample portions of the background for Photoshop to base its selection range. 2. Double-click the magic wand tool icon to display the Tolerance option box on the Options bar. For my image, I entered a Tolerance value of 16, a rela- tively low value, in keeping with the consistency of the background. If your background is less homogenous, you may want to enter a higher value. Make certain you turn on the Anti-aliased check box. 3. Choose Select ➪ Similar. Photoshop should select the entire background. If Photoshop fails to select all the background, choose Edit➪ Undo (Ctrl+Z) and use the rectangular marquee tool to select more portions of the background. You may also want to increase the magic wand’s Tolerance value. If Photoshop’s selection bleeds into the foreground image, try reducing the Tolerance value. 4. Choose Select ➪ Inverse. Or press Ctrl+Shift+I. Photoshop selects the fore- ground image and deselects the background. 5. Modify the selection as desired. If the detail you want to select represents only a fraction of the entire image, Shift+Alt-drag around the portion of the image you want to retain using the lasso tool. In Figure 8-10, I Shift+Alt- dragged with the polygonal lasso tool to draw a straight-sided outline around the selection. 6. Congratulations, you’ve isolated your complex image. Now you can filter your image, colorize it, or perform whatever operation inspired you to select this image in the first place. I wanted to superimpose the image onto a differ- ent background, so I copied the image to the Clipboard (Ctrl+C), opened the desired background image, and then pasted the first image into place (Ctrl+V). The result, shown in Figure 8-11, still needs some touching up with the paint and edit tools, but it’s not half bad for an automated selection process. 337 Chapter 8 ✦ Selections and Paths Figure 8-10: Shift+Alt-drag with the polygonal lasso tool to intersect the area you want to select with a straight-sided outline. Figure 8-11: The completed selection superimposed onto a new background. 338 Part III ✦ Selections, Masks, and Filters Whenever you introduce a selection into another image— by copying and pasting or by dragging the selection and dropping it into another image window— Photoshop automatically assigns the selection to a new layer. This is a great safety mechanism because it prevents you from permanently affixing the selection to its new back- ground. But it also limits your file format options when saving an image; you can’t save in a format other than the native Photoshop format, PDF, or TIFF (the last two now offer layer support) without first flattening the image. For the big story on lay- ers, read Chapter 12. Softening selection outlines You can soften a selection in two ways. The first method is antialiasing, introduced in Chapter 5. Antialiasing is an intelligent and automatic softening algorithm that mimics the appearance of edges you’d expect to see in a sharply focused photograph. Where did the term antialias originate? Anytime you try to fit the digital equivalent of a square peg into a round hole —say, by printing a high-resolution image to a low-resolution printer— the data gets revised during the process. This revised data, called an alias, is frequently inaccurate and undesirable. Antialiasing is the act of revising the data ahead of time, essentially rounding off the square peg so it looks nice as it goes into the hole. According to a reader who spent time at MIT’s Architecture Machine Group, “We did the first work with displaying smooth lines. We called the harsh transitions jaggies and the display process dejaggying. Somehow, this easy-to-understand term slid sideways into ‘alias’ (which it isn’t, really, but it’s too late to change).” Now you know. When you draw an antialiased selection outline in Photoshop, the program calcu- lates the hard-edged selection at twice its actual size. The program then shrinks the selection in half using bicubic interpolation (described in Chapter 2). The result is a crisp image with no visible jagged edges. The second softening method, feathering, is more dramatic. Feathering gradually dissipates the selection outline, giving it a blurry edge. Photoshop accommodates partially selected pixels; feathering fades the selection both inward and outward from the original edge. You can specify the number of pixels affected either before or after drawing a selec- tion. To feather a selection before you draw it with a marquee or lasso tool, enter a value in the Feather option box, found on the Options bar in Photoshop 6. To feather a selection after drawing it, choose Select ➪ Feather or press Ctrl+Alt+D. You also can right-click in the image window and then choose Feather from the pop-up menu that appears next to your cursor. The Feather Radius value determines the approximate distance over which Photoshop fades a selection, measured in pixels in both directions from the original selection out- line. Figure 8-12 shows three selections lifted from the image at the bottom of the figure. Note Note [...]... to grow comfortable with the pen tool, for example, because it requires you to draw a selection outline one point at a time Photoshop Note 6 If you’re familiar with Illustrator’s pen tool and other path-editing functions, you’ll find Photoshop s tools nearly identical Photoshop doesn’t provide the breadth of options available in Illustrator, but the basic techniques are the same Photoshop 6 includes... independent — and entirely changeable — as long as a selection tool is active In addition to moving a selection outline, you can transform it by choosing Select ➪ Transform Selection Photoshop Chapter 8 ✦ Selections and Paths 6 When you select this command, Photoshop displays a transformation boundary framed by eight handles, as shown in Figure 8-23 You can drag the handles to adjust the outline as described... in Photoshop 5, evidently wasn’t a huge hit on the path tool circuit In Version 6, the magnetic pen no longer appears in the toolbox But if you select the freeform pen and then select the Magnetic check box on the Options bar, the freeform pen does a dandy impression of the magnetic pen Click the edge of the foreground element you want to select and then move the cursor along the edge of the shape Photoshop. .. freeform pen, described next (As always, the shortcuts assume that you turned off the Use Shift Key for Tool Switch option in the Preferences dialog box.) Photoshop Freeform pen: Drag with this tool to create a path that automatically follows the twists and turns of your drag Simplicity at its best; control at its lowest Luckily, you can turn around and edit the path after you initially draw it 6 The... double-click inside the boundary To cancel the transformation, press Escape 6 Alternatively, click the check mark button near the right end of the Options bar to apply the transformation or click the X button to cancel out of the operation Chapter 8 ✦ Selections and Paths The untimely demise of floating selections As you may (or may not) recall, Photoshop 4 bludgeoned floating selections into a state... Ctrl-dragging in Photoshop Making precise movements Photoshop provides three methods for moving selections in prescribed increments In each case, the move tool is active, unless otherwise indicated: ✦ First, you can nudge a selection in 1-pixel increments by pressing an arrow key on the keyboard or nudge in 10-pixel increments by pressing Shift with an arrow key This technique is useful for making precise... boxes, as shown at the bottom of the figure These options take the place of those formerly accessed through the Numeric Transform dialog box You can enter specific values to relocate, size, rotate, and skew the selection outline precisely The handles and Options bar controls work just as they do for the Edit ➪ Free Transform command, which I cover in gripping detail in Chapter 12 To save you the backbreaking... Filters Drag outside to rotate Drag a handle to scale Transformation origin Relative to transformation origin Constrain Proportions Position Scale Rotate Skew Set origin point Figure 8-23: After choosing Select ➪ Transform Selection, you can scale the selection outline (top) and rotate it (bottom), all without harming the image in the slightest Photoshop When you get the selection outline the way you... of the shape Photoshop automatically assigns points as it deems appropriate 355 3 56 Part III ✦ Selections, Masks, and Filters Add anchor point: Click an existing path to add a point to it Delete anchor point: Click an existing point in a path to delete the point without creating a break in the path’s outline Photoshop 6 Photoshop Convert point: Click or drag a point to convert it to a corner or smooth... to choose when After you create a path, you can select it or edit it by using the two tools on the flyout directly above the pen tools flyout: Photoshop Chapter 8 ✦ Selections and Paths 6 Path component selection tool (black arrow): This tool, new to Photoshop 6, selects an entire path Just click inside the path to select it If you created subpaths, the tool selects only the one underneath your cursor . options. Click the mode you want to use. Tip Normal Add IntersectSubtract 6 Photoshop 6 333 Chapter 8 ✦ Selections and Paths Photoshop displays special cursors to help you keep track of a tool’s. with the tool for a short distance. With the mouse button still down, release Shift and press Alt. Then click around as you normally would, while keeping the Alt key down. 6 Photoshop 6 Tip 334 Part. have less reason to take advantage of those changes than you will the new ranges for Expand and Contract. 6 Photoshop 6 Tip 335 Chapter 8 ✦ Selections and Paths Both Expand and Contract have a flattening