Adobe Photoshop CS4 - Manual (Page 269)

262 USING PHOTOSHOP CS4
Selecting and masking
Last updated 1/10/2010
Create a selection around a selection border
The Border command lets you select a width of pixels inside and outside an existing selection border. This can be useful
when you need to select a border or band of pixels around an image area, rather than the area itself, for example to
clean up a halo effect around a pasted object.
Original selection (left), and after Border command: 5 pixels (right)
1 Use a selection tool to make a selection.
2 Choose Select > Modify > Border.
3 Enter a value between 1 and 200 pixels for the border width of the new selection, and click OK.
The new selection frames the original selected area, and is centered on the original selection border. For example, a
border width of 20 pixels creates a new, soft-edged selection that extends 10 pixels inside the original selection border
and 10 pixels outside it.
Expand a selection to include areas with similar color
Do one of the following:
• Choose Select > Grow to include all adjacent pixels falling within the tolerance range specified in the Magic Wand
options.
• Choose Select > Similar to include pixels throughout the image, not just adjacent ones, falling within the tolerance
range.
To increase the selection in increments, choose either command more than once.
Note: You cannot use the Grow and Similar commands on Bitmap mode images or 32-bits-per-channel images.
Clean up stray pixels in a color-based selection
1 Choose Select > Modify > Smooth.
2 For Sample Radius, enter a pixel value between 1 and 100, and click OK.
For each pixel in the selection, Photoshop examines the pixels around it, to the distance you specify in the radius
setting. If more than half of these surrounding pixels are selected, the pixel remains in the selection, and the unselected
pixels around it are added to the selection. If less than half the surrounding pixels are selected, the pixel is removed
from the selection. The overall effect is to reduce patchiness and smooth sharp corners and jagged lines in the selection.
Refine selection edges
The Refine Edge option improves the quality of a selection’s edges and allows you to view the selection against different
backgrounds for easy editing.