<li class="Bulleted"><a href="12-Selections8.html#1010111">Combining Selections Using Boolean Operations</a></li><br/>
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<h2 id="1010111" class="Heading1">
<a name="1010111"> </a>Combining Selections Using Boolean Operations
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<a name="1010897"> </a>When you save selections, you can use Boolean operations (add, subtract, and intersect) to combine the saved selection with an existing channel.
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<a name="1010914"> </a>Adding a selection combines it with the existing channel. Subtracting a selection cuts it out of the existing channel. When you intersect a selection, you include only those parts that are common to the selection and the existing channel.
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<a name="1010907"> </a>For information about specifying Boolean operations when saving selections, refer to <a href="12-Selections6.html#1010785">"To modify an existing channel:"</a>.
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<a name="1010113"> </a>When you load saved selections, or channels, you can use Boolean operations to combine the loaded channel with the current selection.
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<a name="1010114"> </a>Adding a channel combines it with the current selection. Subtracting a channel cuts it out of the current selection. When you intersect a channel, you include only those parts that are common to the current selection and the loaded channel.
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<a name="1010882"> </a>For information about specifying Boolean operations when loading selections, refer to <a href="12-Selections7.html#999261">"To load a selection from a channel:"</a>.
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<a name="1010967"> </a>There are many practical uses for loading a selection using Boolean operations. For example, in the owl image below, the artist created and saved selections for each area she wanted to work with separately-the eyes, beak, and outline.
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<p id="1010974" class="Body">
<a name="1010974"> </a>To show the selections clearly in the graphics below, the selections were saved to channels, reloaded, and displayed as red overlays. For information about displaying channels as colored overlays, refer to <a href="13-Channels5.html#1010461">"To view a channel as a colored overlay:"</a>.
<a name="1010145"> </a><i>The "head" channel is created by loading the "outline" channel and subtracting the "eyebeak" channel.
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<li class="SmartList1"><a name="1010146"> </a>A rough "face" selection is drawn with the Lasso tool. The eyes, beak, and a portion of the background are included.</li>
<a name="1010151"> </a><i>The original "face" selection.
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<li class="SmartList1"><a name="1010152"> </a>The "head" channel (the outline with eyes and beak subtracted) is loaded and intersected with the rough "face" selection. This removes the eyes, beak, and background portion. </li>
<a name="1010157"> </a><i>The modified "face" selection after loading and intersecting the "head" channel.
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<li class="SmartList1"><a name="1010158"> </a>The resulting selection is saved to the "face" channel.</li>
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<a name="1010159"> </a>Now, with a precise selection of the face, it's easy to control brush strokes and constrain effects.
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<p id="1010160" class="Body">
<a name="1010160"> </a>You can also combine selections when you create them by adding to, or subtracting from, the current selection. You can combine selections made with different tools. For more information, refer to the procedures <a href="12-Selections4.html#1010220">"To add to a selection:"</a> and <a href="12-Selections4.html#1010228">"To subtract from a selection:"</a>.
