Working with selections : Modifying the edges of selections
 
Modifying the edges of selections
You can modify the edges of a selection by smoothing its boundary or by adding a border.
To smooth the boundary of a selection
Edit workspace 
1 Choose Selections Modify Smooth.
The Smooth Selection dialog box appears.
2 Mark or unmark the following options:
Anti-alias — smooths the edges of the selection
Preserve Corners — preserves the shape of the corners. Unmark this check box if you want to smooth the corners.
3 Specify values for one or both of the following controls:
Smoothing amount — specifies the amount of smoothing to apply around the selection
Corner scale — specifies the amount of smoothing to apply around the corners of the selection. This control is not available when the Preserve Corners check box is not marked.
4 Click OK.
You can click the Toggle Selection button in the Smooth Selection dialog box to toggle between a preview of the selection and a preview of the selection and the rest of the image.
To add a border to a selection
Edit workspace 
1 Choose Selections Modify Select Selection Borders.
The Select Selection Borders dialog box appears.
2 Mark one of the following options to set the position of the feathering:
Inside
Outside
Both
3 Type a value in the Border width box.
If you want to smooth the edges of the selection border, mark the Anti-alias check box.
4 Click OK.