Adobe Photoshop CS4 - Manual (Page 270)

263 USING PHOTOSHOP CS4
Selecting and masking
Last updated 1/10/2010
You can also use Refine Edge options to refine a layer mask. See “ Change mask opacity or refine edges ” on page 326.
1 Create a selection with any selection tool.
2 Click Refine Edge in the selection tool options bar or choose Select > Refine Edge to set options for adjusting the
selection:
Radius Determines the size of the region around the selection boundary in which edge refinement occurs. Increase the
radius to create a more exact selection boundary in areas with soft transitions or fine detail, such as those in short hair
or fur, or blurred boundaries.
Contrast Sharpens selection edges and removes fuzzy artifacts. Increasing contrast can remove excessive noise near
selection edges caused by a high Radius setting.
Smooth Reduces irregular areas (“hills and valleys”) in the selection boundary to create a smoother outline. Enter a
value or move the slider from 0 to 100.
Feather Creates a soft-edged transition between the selection and its surrounding pixels. Enter a value or move the
slider to define the width of the feathered edge from 0 to 250 pixels.
Contract/Expand Shrinks or enlarges the selection boundary. Enter a value or move the slider to set the amount from
0 to 100% to expand, 0 to -100% to contract. Most useful for making subtle adjustments to soft-edged selections.
Shrinking the selection can help remove unwanted background colors from selection edges.
For images where the colors of the selected object are distinct from the background, try increasing the Radius, applying
Contrast to sharpen edges, then adjusting the Contract/Expand slider. For grayscale images or images where the colors
of the selected object and the background are very similar, try smoothing first, then the Feather option, then
Contract/Expand.
3 Click a Selection View icon to change view modes. Click Description to view information about each mode.
• Select or deselect Preview to turn edge refinement previewing on or off.
• Click the Zoom tool to zoom in or out while adjusting the selection.
• Use the Hand tool to reposition the image.
Double-click the Quick Mask preview mode icon to change mask color or opacity.
4 To save your selection adjustments, click OK.
Soften the edges of selections
You can smooth the hard edges of a selection by anti-aliasing and by feathering.
Anti-aliasing Smooths the jagged edges of a selection by softening the color transition between edge pixels and
background pixels. Because only the edge pixels change, no detail is lost. Anti-aliasing is useful when cutting, copying,
and pasting selections to create composite images.
Anti-aliasing is available for the Lasso tool, the Polygonal Lasso tool, the Magnetic Lasso tool, the Elliptical Marquee
tool, and the Magic Wand tool. (Select a tool to display its options bar.)
Note: You must specify this option before using these tools. After a selection is made, you cannot add anti-aliasing.
Feathering Blurs edges by building a transition boundary between the selection and its surrounding pixels. This
blurring can cause some loss of detail at the edge of the selection.
You can define feathering for the Marquee tools, the Lasso tool, the Polygonal Lasso tool, or the Magnetic Lasso tool
as you use the tool, or you can add feathering to an existing selection.