Task 6 How to Modify Selections

To select complex shapes and areas, you must sometimes combine multiple selection methods. Adding or subtracting from a selection is only the beginning. You also can shrink or grow a selection, smooth out sharp corners, and tweak or skew the selection area in any direction. This task shows the top 12 shortcuts for working with selections. Combine them as you see fit to select exactly the right area of your image.

1. Adding to Selections

To add to a selection, hold the Shift key as you're using any of the Photoshop selection tools. Alternatively, click the Add to Selection button in the Options bar. A plus sign appears next to the mouse pointer to show that you're adding to the current selection.

2. Subtracting from Selections

To subtract from a selection, hold the Alt key (Windows users) or the Option key (Mac users) as you're using any of the Photoshop selection tools. Alternatively, you can click the Subtract from Selection button in the Options bar. A minus sign appears next to the mouse pointer to show that you're subtracting from the current selection.

3. Intersecting Selections

With an area selected, you can introduce a second, overlapping selection so that the final selection is made up of only the common, intersecting areas. First, select an area. Then press Shift+Alt (Windows users) or Shift+Option (Mac users) as you draw a second selection that overlaps the first. Alternatively, click the Intersect with Selection button in the Options bar. An x appears next to the mouse pointer as you do this. After you release the mouse and the keyboard keys, only the intersecting area remains selected.

4. Nudging a Selection

After you select an area, you can nudge the selection area up, down, left, or right one pixel at a time. Select any of the selection tools in the toolbox and press the arrow keys on your keyboard.

5. Inverting Selections

To invert an active selection, choose Select, Inverse. This action selects the exact opposite of the current selection. In this example, after you select the menu command, everything on the image area will be selected except the areas that are currently selected.

6. Smoothing Selections

Smoothing a selection involves a gradual rounding of corners or sharp edges. To smooth an active selection, choose Select, Modify, Smooth. In the Smooth Selection dialog box that appears, enter a value from 1 to 100 pixels to determine the degree of smoothing. Click OK to modify the selection. Repeat this step as desired to smooth the selection even more.

7. Expanding Selections

Expanding a selection means just what it says: expanding the overall area of a selection by a specific number of pixels. To expand an active selection, choose Select, Modify, Expand. In the Expand Selection dialog box that appears, enter a value from 1 to 100 pixels to determine the degree of expansion. Click OK to modify the selection. Repeat this step as desired to expand the selection even more.

8. Contracting Selections

Contracting a selection makes the overall selection area smaller. To contract an active selection, choose Select, Modify, Contract. In the Contract Selection dialog box that appears, enter a value from 1 to 100 pixels. Click OK to modify the selection. Repeat this step to contract the selection even more.

9. Isolating Selection Borders

When you're working with geometric selections, there might be times when you want to apply an effect only to the border of a selected area. Choose Select, Modify, Border. In the Border dialog box that appears, enter a value from 1 to 200 pixels to specify the width of the border. This option thickens the selection line to the width you specify and makes that line the active selection area. Click OK to modify the selection.

10. Feathering a Selection

Feathering a selection involves vignetting the selection edges, softening any effects that are applied to the selected area. To feather a selection, choose Select, Feather. In the Feather Selection dialog box that appears, type a feather value from 0.2 to 250 pixels and click OK. To set the feather amount before making a selection, enter a pixel value in the Feather field of the Options bar.

11. Selecting Similar Colors

After you select an area, you can select all other pixels in the image that have the same color value. This capability can be effective if you want to select multiple colored objects or areas. To do this, select a color or range of colors and then choose Select, Similar. All pixels with similar pixel values are selected.

12. Transforming Selections

You can distort or skew a selection using any of the Transform options described in Part 10, Task 6, "How to Transform Layers." To transform an active selection, choose Select, Transform Selection. A bounding box appears around the selection; drag the handles to modify the selection area. Alternatively, right-click (Windows users) or Ctrl+click (Mac users) to view a context menu of transforming options. The Options bar also provides a variety of methods to help in transforming the selection. Double-click inside the bounding box or press Enter (Windows users) or Return (Mac users) to apply the transformation. Press the Esc key to cancel the transformation changes.

How-To Hints

Smoothing Selections to Make Rounded Corners

Use the Smooth Selection technique from step 6 to create rounded-corner rectangular selections. A 16-pixel rounding value works very well with 72dpi web images. The result is ready to be stroked or filled to create a rounded-corner box shape.

Using Tolerance with Select Similar

The Select Similar command in step 11 uses the Tolerance setting from the Magic Wand Options palette to determine how it selects similar colors. If you set the Tolerance value high, more similar colors are selected; if you set the Tolerance value low, a more narrow range of colors is selected.