You
can use the Quick Selection tool 
to
quickly “paint” a selection using an adjustable round brush tip.
As you drag, the selection expands outward and automatically finds
and follows defined edges in the image.
- To change the brush tip size, click the Brush pop-up menu in the options bar, and type in a pixel size or drag the slider. Use the Size pop‑up menu options to make the brush tip size sensitive to pen pressure or a stylus wheel.
Note:
When creating a selection, press the right bracket (]) to increase the Quick Selection tool brush tip size; press the left bracket ([) to decrease the brush tip size.
The selection grows as you paint. If updating is slow, continue to drag to allow time to complete work on the selection. As you paint near the edges of a shape, the selection area extends to follow the contours of the shape edge.
Painting with the Quick Selection tool to extend the selection
Note:
If you stop dragging and then click or drag in a nearby area, the selection will grow to include the new area.
- To subtract from a selection, click the Subtract From option in the options bar, then drag over the existing selection.
(Optional) Click Refine Edge to further adjust the selection boundary. See Refine selection edges.
.)The Magic Wand tool lets you select a consistently colored area (for example, a red flower) without having to trace its outline. You specify the selected color range, or tolerance, relative to the original color you click.
Note:
You cannot use the Magic Wand tool on an image in Bitmap mode or on 32‑bits-per-channel images.
Tolerance
Determines the color range of selected pixels. Enter a value in pixels, ranging from 0 to 255. A low value selects the few colors very similar to the pixel you click. A higher value selects a broader range of colors.
(Optional) Click Refine Edge to further adjust the selection boundary or view the selection against different backgrounds or as a mask. See Refine selection edges.
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