Selecting Pixels by Color on Your Digital Photo

The selections that you can make with your image-editing program's Magic Wand (or like-named tool) often resemble those you can make with the Lasso or Freehand selection tools. They're freeform shapes and — like selections made with the Add to Selection option turned on — they can encompass several separate areas. The difference between those selection tools and the Magic Wand, however, is that the Magic Wand makes selections based on an initial pixel sample. For example, you can select all the blue areas, all the white areas, or all the areas that are the same as or quite close to any color or shade within your image.

Abracadabra! Using the Magic Wand

The Magic Wand selects pixels within your image based on a pixel that you sample by clicking it. It's a simple process that you can master and use to your advantage if you know exactly how it works.

To use the Magic Wand tool, follow these simple steps:

1. Click the Magic Wand tool to activate it.

2. Click a pixel that's the color of the pixels that you want to select in your image.

3. If you don't get all the pixels that you want, press and hold the Shift key while you continue to click pixels around in the image, adding to the Magic Wand selection.

If you get more pixels in the selection than you want, reduce your selection by switching to Subtract from Selection mode (Photoshop or Elements) or by using the Ctrl key (Command for Mac) to take away from the existing selection. When you click an unwanted area within the selection, those pixels are no longer selected.

If you don't get as much of the image as you want, check the tool's options settings, such as Tolerance, to include more pixels. You can tweak the number of selected pixels by expanding the tolerance; or press the Shift key and click in the additional area that you want to select, in order to add to the selection.

Controlling the wand's magic

You can find any wand settings that you could possibly want to tweak on the tool's Options bar (in Photoshop and Elements) or in the palette or Tool options bar of other image editors. The settings work differently, depending on the application that you use.

In any case, you see a Tolerance setting, which is a threshold for the sensitivity of the wand. The higher the number you set for the Tolerance setting, the more pixels that the software sees as selectable — a risky approach if you're working with a black-and-white photo or a color photo without a lot of color diversity throughout. You can make other application-specific adjustments that, when you use them in conjunction with the Tolerance setting, can get you the exact selection that you want. These adjustments include the following:

• Match Mode (Paint Shop Pro): Lets you choose what pixel attribute you want to compare with the surrounding pixels. You can choose from RGB Value, Hue, Brightness, All Opaque, or Opacity. If you choose RGB Value (the default), the tool compares the surrounding pixels in terms of their levels of red, green, and blue. And, if they're close enough to the sampled pixel (based on the Tolerance that you set), the tool selects them.

• Contiguous (Photoshop/Elements): This check box lets you choose whether the selection includes pixels that aren't touching the sampled pixel or any of the pixels that you selected on the first click with the wand. If you turn on the option (it's off by default), you get a smaller selection, which may be just what you want. If you turn it off, the tool selects any pixels meeting your Tolerance setting, no matter where in the image they appear.

• Use All Layers (Photoshop/Elements): Lets you select pixels on (who'd have guessed it) all the layers of the image. If you turn this adjustment on (it's off by default), you can select all the pixels that meet your tolerance requirements, no matter which layer they're on. If you want to restrict your edits to a particular layer, however, make sure this option is off.

You may find it easier to set your Tolerance setting low so that you don't get more of a selection than you want and then use the Add to Selection option or use the Shift key to augment the selection by clicking again on a new spot, which resamples the image and compares surrounding pixels against a different sample pixel. Like most things in life, you can more easily start small and add what you need than grab too much and then have to give some of it back or start all over again.