Tài liệu Photoshop cs5 by Dayley part 39 pdf

Part III: Selections, Layers, and Channels 266 4. Use the Add to Selection and Subtract from Selection tools to fine-tune your selection. Zoom in on hard-to-define areas and reduce your brush size to make the smaller selec- tions. If you select too much, use the Subtract from Selection to take the extra area out. That is the beginning of creating a selection with the Quick Selection tool. From beginning to end, it took less than five minutes to select the boy off the background of the sample image. Magic Wand tool Nested with the Quick Selection tool is the Magic Wand tool. The Magic Wand tool creates a selec- tion by targeting areas that are the same color. Use this tool if the area you want to select is all a similar color or colors. This works best, of course, if the areas that you don’t want selected are a contrasting color. Magic Wand tool options Before using the Magic Wand tool, you should familiarize yourself with the options displayed above the document window in the Options bar, as shown in Figure 9.7. Familiarizing yourself with these options before you use the tool helps you to get the most out of this tool’s capability. FIGURE 9.7 The Options for the Magic Wand tool Tool presets New, Add, Subtract, and Intersect l Tool presets: You can save and retrieve your favorite tool settings using this drop-down list. Click the little black arrow to see a menu of available options. l New selection: When this option is highlighted, every time you drag the selection brush, you create a new selection and the old selection disappears. l Add to selection: With this option highlighted, everything you select is added to the cur- rent selection. This makes it easy to do the detail work after the initial selection is made. l Subtract from selection: With this option highlighted, you can subtract areas from the current selection. l Intersect with selection: This option selects only those areas that were in the first selec- tion you made, as well as the second, and deselects anything that was selected only once. l Tolerance: The tolerance level determines how many shades of the color you choose with the Magic Wand are selected. A higher tolerance selects more shades; a lower tolerance selects fewer. The level you set depends entirely on your photo. 15_584743-ch09.indd 26615_584743-ch09.indd 266 5/3/10 10:24 AM5/3/10 10:24 AM Chapter 9: Creating Selections 267 l Anti-Alias: This creates a smoother-edged selection. l Contiguous: When this option is on, only the appropriate colors contiguous in the area the Magic Wand is used in are selected. If this option is off, all the color in the document within the tolerance range specified is selected. l Sample all layers: With this options checked, the Quick Selection tool uses color and textures from all available layers to determine the edges of your selection. l Refine Edge: Refining the edge of a selection is the finish work that perfects your selec- tion. This option is covered later in this chapter. Using the Magic Wand In the photo shown in this example, I want to select the pistils to create a stylistic photo where the pistils are the only element of the lily in color. (I know, I know, none of it’s in color as far as you’re concerned, but work with me here.) Using the Magic Wand tool is as easy as following these steps: 1. Choose the Magic Wand tool from the Toolbox, or press Shift +W. The Magic Wand tool is nested behind the Quick Selection tool. Tip If the Magic Wand tool is hidden behind the Quick Selection tool, pressing W activates the Quick Selection tool. Simply press Shift+ W to toggle to the Magic Wand tool. You also can change your preferences so that you don’t need to use the Shift key. Choose Edit ➪ Preferences ➪ General and deselect Use Shift Key for Tool Switch. After you’ve done this, you can toggle through your tools using the single hotkey assigned to the tool without having to use the Shift key at all. n 2. Change the tolerance level. Because I want to select several different shades of orange in my photo and the surround- ing area is cream, I use a high tolerance of 75. 3. Uncheck Contiguous. I am choosing several unconnected areas that are all the same color, so I want to sample the entire document. 4. Click the color in your photo that you want to select. The Magic Wand tool is different from every other selection tool in that it doesn’t require you to click and drag, just click a color. If you want to select several different shades, choose an area that is mid-range between the lightest and darkest shades you want to select. Photoshop selects everything in your photo that is the color you click and uses the tolerance setting to determine the range of other colors that are selected. By choosing a midrange pixel to sample and with a high tolerance on a contrasting background, I got a nearly perfect selection in Figure 9.8. 15_584743-ch09.indd 26715_584743-ch09.indd 267 5/3/10 10:24 AM5/3/10 10:24 AM Part III: Selections, Layers, and Channels 268 FIGURE 9.8 The Magic Wand tool easily selected the bright orange pistils (along with the freckles) on the cream-colored lily. On the Web Site You can try your hand at creating this selection by downloading Figure 9-8 from the Web site. n 5. Use the Add to Selection or Subtract from Selection tools to add or subtract areas from your selection. You can choose an entirely different color to add to the selected area than the color you used for the first selection. Color Range The Color Range selector is not a tool in the Toolbox, but rather a dialog box that can be launched from the Select menu. It works similarly to the Magic Wand because it makes selections primarily based on color, but it gives you a little more control over what is selected by letting you customize the settings and preview the results before making the selection. A unique feature of the Color Range dialog box is that it works within a selection as well as the entire image, so you can make a general selection around the area that you would like to ultimately select color from, and only that area is used in the dialog box, as shown in Figure 9.9. After your selection is made and you click OK in the Color Range dialog box, the original general selection disappears and the selection made by the Color Range dialog box takes its place. 15_584743-ch09.indd 26815_584743-ch09.indd 268 5/3/10 10:24 AM5/3/10 10:24 AM Chapter 9: Creating Selections 269 FIGURE 9.9 The Color Range dialog box is versatile when it comes to selecting color or tonal ranges. On the Web Site Use the Color Range dialog box to select the orange rope in this photo by downloading Figure 9-9 from the Web site. n The Color Range dialog box has the following options: l Select menu: The Select menu gives you the option to use a sample from the image as a basis for your selection, or from the drop-down menu you can choose to use a specific color, tonal ranges, or out-of-gamut colors. l Localized Color Clusters: Select this option if you are choosing more than one color and you want to restrict the selection to the same general area. l Fuzziness: The Fuzziness slider works much like the tolerance levels of the Magic Wand. The higher the fuzziness, the more varied the colors in your selection are. The best thing about it is that you can preview the selected areas as you move the slider, allowing you to set a precise fuzziness level before creating your selection. l Range: The Range slider works with the Fuzziness slider to determine how large an area in your image to select from. Again, having the preview is priceless. l Selection/Image: You can either preview the selection or the image. The Selection pre- view is shown as a mask where the selected areas are anything in the upper half of the brightness scale. In Figure 9.9, the rope is the only item in the image that is selected when the Color Range dialog box is closed. The Image preview is shown just as you see it in your document window, with no indication of what has been selected. This option is handy if you are using the Selection Preview option described next. 15_584743-ch09.indd 26915_584743-ch09.indd 269 5/3/10 10:24 AM5/3/10 10:24 AM Part III: Selections, Layers, and Channels 270 l Selection Preview: This option changes the image in your document window to reflect the areas that are selected. You can choose to display it in several ways: grayscale (which mimics the selection window), black matte, white matte, and quick mask. The option that works best is entirely dependent on the colors in your image and the colors you are selecting. l Save: This option allows you to save your Color Range settings for later use. l Load: This option allows you to load saved Color Range settings. l Eyedropper: This tool is used to select the color. Use it by placing the tip over the color that you want to select and clicking. Every time you do, a new selection is made. l Add to Sample: If you would like to select additional areas after creating an initial selec- tion, you need to use this tool. It adds to your selection rather than replacing it. l Subtract from Sample: This tool subtracts areas from your selection. l Invert: This option is used to create a selection around everything in your image except for the colors that you choose. Selecting by shape The Rectangular and Elliptical tools allow you to select areas in your photo that are roughly those shapes very quickly. A rectangular building and the sun are just two examples. The Row and Column marquees select a one-pixel row the width or height of your image. The Marquee tools can be found in the same “drawer” of the Toolbox as shown in Figure 9.10. Click and hold the triangle at the bottom of the Rectangular Marquee to choose between them or press Shift+M to toggle between them. FIGURE 9.10 The Marquee tools are found together in the Toolbox. The Marquee options The Options bar is identical for the Marquee tools, except that some options are grayed out when the Column and Row Marquee tools are selected. These are the options: l Tool presets: You can save and retrieve your favorite tool settings using this drop-down list. Click the little black arrow to see a menu of available options. l New selection: When this option is highlighted, every time you drag the selection brush, you create a new selection and the old selection disappears. 15_584743-ch09.indd 27015_584743-ch09.indd 270 5/3/10 10:24 AM5/3/10 10:24 AM Chapter 9: Creating Selections 271 l Add to selection: With this option highlighted, everything you select is added to the cur- rent selection. This makes it easy to do the detail work after the initial selection is made. l Subtract from selection: With this option highlighted, you can subtract areas from the current selection. l Intersect with selection: This option selects only those areas that were in the first selec- tion you made as well as the second, and deselects anything that was selected only once. Note When adding to a selection, subtracting from a selection, or creating an intersection, you can use the tools interchangeably. You can add an ellipse to a rectangle or add a rectangle to a selection made with the Quick Selection tool. n l Feather: This makes the specified pixels on the edges of the selection gradually transpar- ent. This allows changes you make to the selection to blend with the surrounding areas, whether you apply an adjustment to the selection or create a mask with the selection. This option is not available with the Row and Column Marquees because you can’t feather a single pixel line. l Anti-Alias: This creates a smoother-edged selection. This option is available only for the Elliptical Marquee tool because the other tools have straight-lined selection borders and don’t require smoothing. l Style: This allows you to choose Normal to freehand your selection, Fixed Ratio to free- hand a selection that is constrained to a certain ratio, or Fixed Size to type in exact values for your selection. l Width and Height: Whether you want to set a ratio or an actual dimension, type the width and height in these boxes. You don’t have to use pixels (px); you can type in inches (in) or centimeters (cm). l Refine Edge: Refining the edge of a selection is the finish work that perfects your selec- tion. This option is covered later in this chapter. The Rectangle Marquee tool The Rectangle Marquee tool can be used to easily select rectangular objects in your image. Of course, it’s not very often that you want to select something that’s a perfect rectangle in a two- dimensional image; even buildings usually have a skewed shape due to perspective. A more realis- tic use for the tool is to create a new document from a selected portion of your photo without overwriting the original photo or to select an area of your photo that you want “framed.” To create a rectangular selection, check your options on the Options bar. Do you want the edges of your selection feathered? Perhaps you are creating different print sizes of the same document, so you need to set the width and height for a 5x7 or 8x9 ratio setting. After you have double-checked all your options, click the Rectangle Marquee tool in the Toolbox and drag diagonally across the area of your image that you want to select. Figure 9.11 shows a rectangular selection that was cre- ated with a 090 pixel feather. The edges are rounded because of the feather. I turned on the Quick Mask so you could see the effects of the feathered edges. 15_584743-ch09.indd 27115_584743-ch09.indd 271 5/3/10 10:24 AM5/3/10 10:24 AM Part III: Selections, Layers, and Channels 272 FIGURE 9.11 Using the Quick Mask makes it easy to see how feathering the edges of a selection softens it. The Elliptical Marquee tool The Elliptical Marquee tool can be used to select round or oval objects in your image, to copy rounded areas of your image into other documents, or to create a vignette. I often use it when cor- recting a tough case of red-eye. It’s a little trickier to use than the Rectangle Marquee tool, because you have to imagine a box around the oval you want to draw and start at the top corner of that box to get the selection placed just right. It’s mostly a matter of practice and trial and error. The good news is that if you get the right size, you can always pick the selection up and move it to the right position. Tip Holding down the Shift key while you use either the Rectangle or the Elliptical Marquee tool results in a per- fect square or a perfect circle, depending on the tool, of course. n Using the Lasso tools The Lasso Selection tools have been in Photoshop much longer than the Quick Selection tools and in many ways have been superseded by them. Before the Quick Selection tool, the Magnetic Lasso was the best tool in the arsenal for selecting irregular edges that blended into the background; now mine’s a bit dusty. The Lasso and the Polygonal Lasso tools can still be very useful, and I show you how to use them. Lasso tool options The options for the Lasso and the Polygonal Lasso tool are identical. They are also very similar to the options for the previous selection tools discussed in this chapter. The Magnetic Lasso tool has the most involved option menu of all the selections tools, so I cover the additional options in the Magnetic Lasso tool section. l Tool presets: You can save and retrieve your favorite tool settings using this drop-down list. Click the little black arrow to see a menu of available options. 15_584743-ch09.indd 27215_584743-ch09.indd 272 5/3/10 10:24 AM5/3/10 10:24 AM . want to select. Photoshop selects everything in your photo that is the color you click and uses the tolerance setting to determine the range of other colors that are selected. By choosing a midrange. Lasso tools The Lasso Selection tools have been in Photoshop much longer than the Quick Selection tools and in many ways have been superseded by them. Before the Quick Selection tool, the Magnetic. Part III: Selections, Layers, and Channels 266 4. Use the Add to Selection and Subtract from Selection