Using Adobe Photoshop CS, Part 1 - Lasso Tools
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Although the Marquee selection tools can be quite helpful, chances are there will be plenty of times when you'll need to select something that isn't rectangular or elliptical in shape. The Lasso tool enables you to make irregularly shaped selections. Simply choose the Lasso tool and press the mouse button. As you drag, you'll see a line appear. When you release the mouse button, Photoshop will close the path and turn it into a selection (see Figure 5.21). All the options we spoke about for the Marquee tools are available here as well (adding, subtracting, moving, and so on).
If you're not as comfortable using a mouse, it can be difficult to make clean selections using the Lasso tool (as with anything, practice helps). Don't fret though-Photoshop has two variations of the Lasso tool that might help:
Polygonal Lasso tool-I personally use this selection tool more than any other, and I find it extremely useful for many tasks, including creating silhouettes (which we'll discuss later in the chapter). Rather than having to press the mouse and drag it all over your screen, you can click once and then move your cursor to the next spot and click again. A "rubber band" follows your cursor around to give you visual feedback of where your selection path will be drawn (see Figure 5.22). You can either click on the original point to close your path and turn it into a selection or simply double-click to have Photoshop automatically close the path for you.
Figure 5.21 A selection created with the Lasso tool.
Figure 5.22 Making a selection using the Polygonal Lasso tool.
Tip -Holding the (Option) [Alt] key while using the regular Lasso tool makes it act just like the Polygonal Lasso tool.
Magnetic Lasso tool-You spent enough money on your computer and on the software you're using, so why are youl eft doing all the work? Shouldn't the computer be doing the work for you? Well, the Magnetic Lasso tool does it's part-it automatically detects edges as you use it. An edge here is defined as a shift or change between one color and another. As you drag along an edge with the Magnetic Lasso tool, it automatically detects the edge and draws a path along it (see Figure 5.23). Double-clicking with the tool will automatically close the path and turn it into an active selection.
Figure 5.23 Making a selection using the Magnetic Lasso tool.
If you look at the Tool Options bar when you have the Magnetic Lasso tool selected, you can see various options that control the sensitivity of the tool (see Figure 5.24). Width refers to how far the tool will look for an edge from where your cursor is. Edge Contrast controls how sensitive the tool is with regard to differences in color. A higher number will find only an edge that is a high-contrast one, whereas a lower number will look for more subtle shifts in color. The Frequency value determines how many points the tool uses to draw out the path. A higher number will yield a path that is more precise, and a lower number will result in a smoother path.
Figure 5.24 The settings for the Magnetic Lasso tool.
Tip -With Caps Lock turned on, Photoshop will display the cursor for the Magnetic Lasso tool as the size of the Width setting, making it easier to trace over edges of color. Pressing the right or left bracket on your keyboard will increase or decrease the Width setting by one pixel.
Magic Wand
For selecting areas of similar color, you can use the Magic Wand tool. By default, the Magic Wand takes the area that you click on and selects all pixels of similar color adjacent to it. Simply click on an area of your image. If you uncheck the Contiguous option in the Tool Options bar, Photoshop will select all similarly colored pixels throughout the entire document.
You can control how sensitive the Magic Wand tool is by adjusting the Tolerance setting in the Tool Options bar (see Figure 5.25). A low tolerance number means the Magic Wand will select only pixels that are closer to the color that you clicked on. For example, if you click on a dark blue color with a low tolerance, the Magic Wand will select only dark blue pixels-but with a higher tolerance, other shades of blue will be selected as well (see Figure 5.26).
Figure 5.25 The Tool Options bar for the Magic Wand tool.
Figure 5.26 A selection made with a high tolerance setting (left) and a selection made with a low tolerance setting (right).
Tip -If you don't see the Tolerance setting in the Tool Options bar, it means you haven't selected the Magic Wand tool from the toolbox.
As with the other selection tools, you can use the Add, Subtract, and Intersect options with the Magic Wand tool.
Note -Another way to make a selection is by using a feature called Quick Mask, which we'll cover later in the chapter.
 This chapter is from Adobe Creative Suite, by Mordy Golding (Sams, 2003, ISBN: 0672325918). Check it out at your favorite bookstore today. Buy this book now.
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