79. Add Areas Similar to the Current Selection
Before You Begin
70 About Making Selections
78 Expand or Shrink a Selection
It is often difficult to select all the pixels that make up the area you want to select. For example, you might want to select the blossom of a firework explosion. Although you can use one of the Lasso tools to select the bloom, tracing around all the tendrils of the explosion of light can be tedious. Fortunately, Photoshop Elements provides tools that enable you to expand a selection to include pixels that match those in the current selection.
You have two options for expanding the current selection by adding similar pixels: If you want to select all the pixels in the image that match the current selection, choose the Select, Similar command. In a photo of a troop of costumed dancers in which you have selected a portion of a single blue costume (maybe using the Lasso tool and selecting an area quickly and well inside the borders of the costume), this command selects not only the rest of the original blue costume, but all similarly colored blue costumes in the image (and any other blue pixels, which you can usually quickly deselect by lassoing them). If you want to select only the pixels adjacent to the current selection (for example, only the remainder of the single blue costume), choose the Select, Grow command instead. You can use this process for a selection you intend to invertfor example, to quickly select a similarly colored background around an object.
Make First Selection
Open the image you want to work with in the Editor in Standard Edit mode and save it in Photoshop (*.psd) format. In the Layers palette, choose the layer that contains the data you want to select and then use any selection tool to make the initial selection in the image. You can use any of the selection tools to select the area containing the pixels you want to match. For example, you can use the Elliptical Marquee tool to select a circular area containing the pixels you want. The colors and tone in this selection will be used to find matching pixels in the image.
Adjust the Tolerance
Select the Magic Wand tool on the Toolbox and adjust the Tolerance value on the Options bar to suit your needs. Remember that a higher Tolerance allows the Editor to add pixels to your selection that don't match the pixels in your original selection all that closely. See 76 Select Areas of Similar Color.
You control how closely pixels must match the pixels in the current selection with the Tolerance setting, available with the Magic Wand tool. Basically, before using the Similar or Grow commands, you change to the Magic Wand tool (even if you didn't use that tool to create the selection), and adjust the Tolerance to a level that describes what kind of a match to the current selection you're looking for. See 76 Select Areas of Similar Color for more information on using the Magic Wand tool. Keep in mind that you want a low Tolerance level to most closely match the current selection. Specify a higher Tolerance value to include pixels with a wider range of colors and tone.
Add Similar Areas
Choose Select, Similar to select all areas in the image that are similar in color and tone to the area you selected in step 1.
Or Grow Selection
Alternatively, choose Select, Grow to expand the current selection to include only neighboring pixels of similar color and tone.
View the Result
When you have correctly adjusted the Tolerance value, all the matching pixels are selected. After you're satisfied with the selection, make changes to the data within the selection, copy or cut the data to another image or layer, or delete the data within the selection. Save the PSD file and then resave the file in JPEG or TIFF format, leaving your PSD image with its layers (if any) intact so that you can return at a later time and make different adjustments if you want.
I wanted to select this photo of Kermit the Frog for a birthday card I was designing, taken while visiting a recent exhibit at a children's museum. I tried to select him using the Magic Wand, but even at a high Tolerance setting, it didn't want to easily grab all those green pixels in the rug. And I wasn't looking forward to trying to use the Magnetic Lasso to outline Kermit, given all those fingers and the tiny pole his hand was sitting on. So, I made a quick selection of the red curtain behind him, set the Tolerance to 75, and used the Select, Grow command to grab similar neighboring pixels. It took a few seconds more to grab a few stray pixels, and then I inverted the selection and selected Kermit.
If these commands cause too much of the image to be selected, undo them and try reducing the Tolerance setting and then applying the Grow or Similar command again. Alternatively, increase the Tolerance value to include a broader range of colors in the selection.