Life is all about making choices, and the time you spend in Photoshop is no exception. Perhaps the biggest decision you'll make is which part of an image to edit—after all, your edits don't have to affect the whole thing. Using a variety of Photoshop tools, you can tell the program exactly which portion of the image you want to tinker with, right down to the pixel, if you so desire. This process is called making a selection.
As you'll learn in this chapter, Photoshop has a bunch of tools that you can use to create selections based on shape, color, and other attributes. You can also draw selections by hand, although that requires a bit of mouse prowess. True selection wisdom lies in learning which selection tool to start with, how to use the tools together, and how to fine-tune your selections quickly and efficiently. The following pages will help you with all that and then some.
Fill it with color or pixels from the image's background. Normally, the Edit→Fill command (Filling a Layer with Color) floods an entire layer with color, but by creating a selection first, you can color just that area. In CS5, you can use the Fill command in conjunction with a selection to delete a person from your photo as if they were never there (see Filling a Selection with Color).
Add an outline. You can add a stroke (Photoshop's term for an outline) to any selection. For instance, you can use selections to give your photo a black border (Stroking (Outlining) a Selection) or to circle yourself in a group photo (Stroking (Outlining) a Selection).
Move it around. To move part of an image, you need to select it first. You can even move selections from one document to another, as discussed on Moving Selections. For example, a little head swapping is great fun after family reunions and breakups. If you want to stick your ex's head onto a ballerina's body, hop on over to Moving Selections.
Resize or transform it. Need to change the size or shape of your selection? No problem: Just make a selection and then transform it into whatever size or shape you need (Transforming a Selection). Photoshop won't reshape any pixels that are in your selected area, just the selection itself.
Use it as a mask. When you create a selection, Photoshop protects the area outside it—anything you do to the image affects only the selected area. For example, if you move the Eraser tool (Fading Images Together) across the edge of a selection, it erases only the area inside the selection. Likewise, if you create a selection before adding a layer mask (Layer Masks: Digital Masking Tape), Photoshop loads the selected area into the mask automatically, letting you adjust only that part of the image. So selections are crucial when you need to correct the lighting in just one area (Chapter 9), or change the color of an object (Changing Color).
This chapter discusses all these options and more. But, first, you need to understand how Photoshop marks selections.
When you create a selection, Photoshop calls up a lively army of animated "marching ants" (shown in Figure 4-1). These tiny soldiers dutifully march around the edge of the selected area, awaiting your command. You can select part of an image, everything on a single layer, or a whole document. Whenever you have an active selection (that is, whenever you see marching ants), Photoshop has eyes only for that portion of your document—any tool you use (except the Type and Shape tools) will affect only the area inside the selection.
Selections don't hang around forever—when you click somewhere else on your screen (outside the selection) with a selection tool, your original selection disappears, forcing you to redraw it. If you want to save a selection to use again later, flip to Saving a Selection.
Figure 4-1. To let you know an area is selected, Photoshop surrounds it with tiny, moving dashes that look like marching ants. Here you can see the ants running around the armadillo. (FYI, the nine-banded armadillo is the state animal of Texas. Aren't you glad you bought this book?)
Select All. This command selects your whole document and places marching ants around the perimeter, which is helpful when you want to copy and paste an entire image into another program or create a border around a photo (see Stroking (Outlining) a Selection). To run this command, go to Select→All or press ⌘-A (Ctrl+A on a PC).
Deselect. To get rid of the marching ants after you've finished working with the selection, choose Select→Deselect or press ⌘-D (Ctrl+D). Alternatively, if you've got one of the selection tools activated in the Tools panel, you can click once outside the selection to get rid of your selection.
Reselect. To resurrect your last selection, choose Select→Reselect or press ⌘-Shift-D (Ctrl-Shift-D). This command reactivates the last selection you made, even if it was five filters and 20 brushstrokes ago (unless you've used the Crop and Type tools, which render the Reselect command powerless). Reselecting is helpful if you accidentally deselect a selection you've been working on for a long time. (The Undo command [⌘-Z or Ctrl+Z] can also help you in that situation.)
Inverse. This command, which you run by going to Select→Inverse or pressing ⌘-Shift-I (Ctrl-Shift-I), lets you flip-flop a selection to select everything you didn't select before. You'll often find it easier to select what you don't want and then inverse the selection to get what you do want (see the box on Selecting the Opposite).
Load a layer as a selection. When talking to people about Photoshop, you'll often hear the phrase "load as a selection," which is (unavoidable) Photoshop-speak for activating a layer that contains the object you want to work with and then summoning the marching ants so they run around that object; that way, whatever you do next affects only that object. To load everything that lives on a single editable layer as a selection, mouse over to the Layers panel and ⌘-click (Ctrl+click) the layer's thumbnail (The Layers Panel); you don't need to have the layer selected. Photoshop responds by putting marching ants around everything on that layer. Alternatively, you can Ctrl-click (right-click on a PC) the layer's thumbnail and then choose Select Pixels from the resulting shortcut menu.
Although you can find most of the commands in this list in the Select menu at the top of your screen (except for loading a layer as a selection), you should memorize their keyboard shortcuts if you want to be smokin' fast in Photoshop.
These next three items live in the Select menu, but they don't actually call up marching ants. Instead, they tell Photoshop to select entire layers (for the lowdown on layers, see Chapter 3):
All Layers. Use this command if you want to select every layer in your document (so you can move several layers at once, for example). To select all layers, choose Select→All Layers or press ⌘-Option-A (Ctrl+Alt+A).
Deselect Layers. This command does the exact opposite of the previous one: It deselects all the layers in your Layers panel, leaving nary a layer highlighted. To run it, choose Select→Deselect Layers.
Similar Layers. Choose this command if you want to select all layers of the same kind (Layer Basics lists the different types of layers). For example, say you want to change the font in all the Type layers in your document. Just select a Type layer and then choose Select→Similar. Photoshop selects all your Type layers and highlights them in the Layers panel so you can modify them all at once. (See Chapter 14 for more on Type layers.)
When you move objects around with the Move tool, you can enlist Photoshop's help in selecting individual layers by turning on Auto-Select in the Options bar. With this setting on, as you click an object in your document, Photoshop tries to guess which layer it's on and select that layer for you.
Now it's time to discuss the tools you can use to make selections. Photoshop has a ton of 'em, so in the next several pages, you'll find them grouped according to which kind of selections they're best at making.