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SHIFT key in action with the Lasso tool, adding a new
area to the selection. Note the + beside the cursor.
The Lasso tool with the ALT or Option key, removing
an area from the selection. See the – symbol beside the cursor.
Rectangular selection with circular areas added and
removed.
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Add or subtract from a selection
To add to a selection, simply hold your SHIFT key down as you create
the new selection. To subtract, hold your ALT or Option key as you trace
around the area you wish to subtract.
In the image at the left, you can see that the selection border around
this flower has an area that must be added to the selection. It is usually
best to increase magnification until you have a very clear view of the
edge. Using the Lasso tool, with the SHIFT key depressed (note the +
beside the cursor), I traced carefully along the edge of the flower.
You can see, though, that once I had the flower edge completed, I did
not require accuracy. The area I am tracing on the interior of the flower
is already selected, so I have no need to spend time following the edge.
The second image at the left shows an area removed by using the Lasso
tool with the ALT key. Again, once I have traced the edge of the object,
I do not need accuracy for the remaining selection, since that area
is already a non-selected area, and removing from it will make no difference.
In this case, the flower was the selected area. If the background area
was the selected area, you would use the opposite tool to accomplish
the same effect.
Of course, you can also use the addition and subtraction to selections
to draw objects. To create the selection shown at the left, I drew a
rectangle, and removed the lower right corner by drawing an ellipse
selection with the ALT key pressed down, to remove the area. Finally,
with the SHIFT key down, I drew another selection with the Elliptical
Marquee tool at the top right corner.
There is no limit to the number of additions or subtractions you can
use to create a selection. However, if you are working on a complex
selection, you may wish to save the selection occasionally as you work
along (see below). Of course, you can always use the History palette
to step back if you lose the selection through a couple of careless
mouse clicks. (Does that sound like experience talking?)
You can also use addition and subtraction with any combination of selection
tools. Do the original selection with the Magic Wand, and clean it up
with any other tool. Start with a Lasso tool selection and add or subtract
a range of color with the Magic Wand. I find it much faster to do a
rough selection and then add or subtract areas, often at high magnification.
TIP: Have you ever started a selection and then realized that
you were too far to the left? Yes, you can move it later, but you need
to know now where to stop the selection. Try this. When you are drawing
a selection, press down your spacebar. You can now move the selection
as you desire, and then resume drawing the selection as soon as you
release the spacebar. Try it a few times until you have it planted in
your mind. I do not use this a lot, but when I do, it is a great time
saver.
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Oval selection in the top image. Bottom image shows
the same selection with the Grow command applied.
Photo © Tom Thomson
Photography. Used with permission.
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Select similar pixels
You can also add to your selection with either the grow or similar commands
in the select menu. If you wish to add pixels of a similar color value,
the range of which is determined by the current Magic Wand Tolerance
level, choose Select>Grow. If your Magic Wand Tolerance is set to
50, any areas containing colors within that range of color will be selected.
This command only selects colors that are joined, or contiguous. The
oval selection at the left contained a wide enough range of color to
select the entire flower when the Grow command was applied.
To select similar color areas anywhere in the document, choose Select>Similar.
Again, the Tolerance, or range of color selected is determined by the
Magic Wand Tolerance value. In the image below, I used the Magic Wand
to select one yellow rectangle. The Select>Similar command automatically
selected the remaining rectangles.
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Transform your selection
Suppose your selection is just a tiny bit too large, or, you would like
to rotate the selection to apply a special effect. No problem. Simply
choose Select>Transform from the main menu, and you have the same
control over your selection as you have for objects.
Selection handles will appear around your selection. Use the corner
handles, plus your SHIFT key to resize the selection proportionately,
or side and top handles to adjust width or height. Position your cursor
over a handle and it will change to a double arrow, indicating that
you can resize the selection in that direction.
Place your cursor on the selection between handles, and the cursor
will change to a curved double arrow. At this point you can click and
drag to rotate your selection. You can move the rotation axis my moving
the icon that is located in the middle of the selection (see the top
image for the default location). Simply click and drag the icon to move
the rotation axis to the required location. Your selection will now
rotate around this point as shown in the sample to the left.
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