Adobe Photoshop Tutorial Part 3: Working with Selections

Modifying Selections

As you learned in the section on using the marquee tools, it’s possible to define irregular selection areas by adding to or subtracting from the original selection marquee. You can use any marquee tool to do this, and change out marquee tools as necessary to define the shape of the final selection.

The selection state options on the Options bar let you switch between selection states, which include Add to selection and Subtract from selection. These states are available for all the marquee tools. But you don’t have to use the Options bar to change selection states; there are a few keyboard shortcuts that make it much faster and easier to add to and subtract from a selection marquee:

• To add to a selection, hold down the Shift key while defining the additional selection area:

• To subtract from the selection, hold down the Alt key (or the Option key, for Mac users) while you define the area you want to remove:

• To subtract from a selection using the intersection method (where the resulting selection is based on the area where both marquees intersect), hold down both the Shift and Alt keys (or Shift and Option keys, for Mac users), while creating the second marquee:

Tip:

You can also access these commands by right-clicking with one of the marquee tools.

If you’re trying to select a portion of a complex image, it may be easier to select the area you don’t want:

1. Select the area you don’t want included in the selection marquee.

1. From the Select menu, select Invert, or right-click and select Select Inverse from the shortcut menu. The selection is inverted so you can work with the remainder of the area:

The Select menu contains some additional commands for working with selections. The following commands are available from the Modify submenu of the Select menu:

• Border adds a new marquee around an existing selection marquee, and the pixels inside the original marquee are deselected, creating a border selection. To apply a border, first create the selection marquee. Then, from the Select menu, select Modify and then Border. In the dialog that opens, enter the width of the border you want in pixels.

As you’ll learn later, you can apply a stroke or fill to a border, as well as other effects.

• Smooth smoothes, or rounds, corners on a selection marquee based on a sample radius you define. Photoshop uses the value you enter into the Smooth Selection dialog to create circles that smooth the corners. The higher the value you enter, the smoother the resulting corners. Below, a sample radius of 5 was entered to create gently rounded corners:

• Expand and Contract expand and contract the selection marquee, respectively. This is a simple way to enlarge or reduce an existing selection marquee based on a specific number of pixels.

In addition, the Grow and Similar commands, also found in the Select menu, function like the Magic Wand tool by selecting all pixels that match others you’ve selected using one of the marquee tools:

• If you select several pixels with one of the marquee tools and then select Grow from the Select menu, Photoshop selects all the neighboring pixels that fall within the range of the selected pixels.
• Similar functions like Grow, but selects all matching pixels, regardless of their location.

Transforming Selections

You can scale, shear, and deform selection outlines using the Transform Selection command in the Select menu:

1. Use one of the marquee tools to select the area you want to transform.
2. From the Select menu, select Transform Selection.
3. A bounding box appears around the selection.

In addition, the Options bar displays fields for changing the position and size of the selection, as well as for entering values for rotating or skewing the selection:

1. You can enter precise values into the Options bar, or you can click and drag one of the handles on the bounding box:

Note that transforming a selection only modifies the selection outline, and not the underlying image. Later, you’ll learn how to stroke and fill a selection outline, as well as apply various effects to it.

Stroking and Filling Selections

One of the most useful features of a selection outline is the ability to paint inside it—without crossing its borders. Everything outside a selection marquee is frozen and can’t be altered by whatever you’re doing within the marquee. This makes selection marquees handy for all kinds of things besides copying, moving and generally transforming a portion of an image.

A few sections back, you learned that you can use the Paint Bucket tool to fill a selection area. But you can also use the Brush or Pencil tool to make more subtle changes to the selected area without affecting any of the pixels outside the selection. In other words, selection marquees give you a handy way to “color within the lines”:

In addition, Photoshop includes a couple of useful commands for stroking and filling a selection:

• To paint along the selection marquee (called stroking the selection), select Stroke from the Edit menu. This opens the Stroke dialog, which lets you define a range of settings:

You can define the width of the stroke, the color, the location of the stroke in relation to the selection marquee, and blending and opacity options. Click OK to apply the stroke. Below, a complex selection border was stroked to create the outline of a bird on a perch:

• To fill the interior of the selection marquee, select Fill from the Edit menu. The Fill dialog lets you specify what to fill the selection with:

You can also specify blending and opacity settings. Click OK to apply the fill:

Congratulations!

Congratulations, you have completed part 3 of our free Adobe Photoshop tutorials.