Graphics Programs Reference
In-Depth Information
Using the Magnetic Lasso
The Magnetic Lasso tool is something like a cross between the lasso and the
polygonal lasso, but with a difference. Like the polygonal lasso, the magnetic
lasso lays down tiny straight segments. But like the regular lasso, it lets you
work freehand. As you drag the magnetic lasso, Photoshop performs real-time
edge detection based upon the contrast between pixels along the edge. In the
following steps you will use the Magnetic Lasso tool to subtract from a selection
you saved earlier.
1.
Reopen the
DomeSelection.psd
file that you saved earlier or go to the
browse to Chapter 7, and open that same file.
2.
Choose Select a Load Selection. Choose Dome from the Channel
drop-down in the Load Selection dialog box (see Figure 7.10). Click OK.
FIGURe 7.10
Loading a saved selection
3.
Press Shift+L to select the Magnetic Lasso tool. Set Feather to 0 px,
select Anti-Alias, and set Width to 10 px, Contrast to 10%, and
Frequency to 100.
4.
Select the Subtract From Selection button on the options bar. Press
F to switch into Full Screen with Menu Bar mode. Press Cmd+= to
zoom into the Baroque architectural element at the bottom of the
photo.
5.
Carefully trace over the silhouette of the Baroque element, magneti-
cally lassoing its structure to remove it from the selection. You don't
have to make a perfect selection: Close is good enough for this tuto-
rial. Double-click when you get to the end of the loop to complete the
selection (see Figure 7.11).
