Softening The Edges Of A Selection - Adobe PHOTOSHOP 5.0 User Manual

To increase the selection in increments, choose
either command more than once.
Note: You cannot use the Grow and Similar
commands on images that are in Bitmap mode.
To smooth a selection:
1 Choose Select > Modify > Smooth.
2 For Sample Radius, enter a pixel value between
1 and 16, and click OK.
Adobe Photoshop checks around each selected
pixel to find any unselected pixels falling within
the specified range. For example, if you enter 16
for the sample radius, the program uses each pixel
as the center of a 33-by-33-pixel area (16 pixels in
the horizontal and vertical directions). If most
pixels in the range are selected, any unselected
pixels are added to the selection. If most pixels are
unselected, any selected pixels are removed from
the selection.
Note: The relationship between physical distance
and pixel distance depends on the resolution of the
image. For example, 5 pixels is a longer distance in a
72-ppi image than in a 300-ppi image. (See "About
image size and resolution" on page 42.)
Softening the edges of a
selection
Photoshop offers two ways to smooth the hard
edges of a selection.
Anti-aliasing Smooths the jagged edges of a
selection by softening the color transition between
edge pixels and background pixels. Since only the
edge pixels change, no detail is lost. Anti-aliasing is
useful when cutting, copying, and pasting selec-
tions to create composite images.
Anti-aliasing is available for the lasso, polygon
lasso, magnetic lasso, elliptical marquee, and
magic wand tools. (Double-click the tool to
display its Options palette.) You must specify this
option before using these tools. Once a selection is
made, you cannot add anti-aliasing.
For an illustration of anti-aliasing, see "Specifying
anti-aliasing" on page 298.
Blurs edges by building a transition
Feathering
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, lasso,
polygon lasso, or magnetic lasso tool as you use the
tool, or you can add feathering to an existing
selection. Feathering effects become apparent
when you move, cut, or copy the selection.
To use anti-aliasing:
Double-click the marquee, lasso, polygon lasso,
1
or magnetic lasso tool to display its Options
palette.
Select Anti-aliased in the Options palette for the
2
selected tool.
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