Where the marquee tools let you select areas of an image in a structured way using squares, circles, lines, the lasso tools add a bit of freeform selection to the mix.. For example, you
Trang 1Mastering the Art of
Selection
Introduction
Mastering Adobe Photoshop requires skill in many diverse
areas While modifying an image's color, enhancing an old
photograph, or removing dust and scratches may require
dif-ferent skills, they have one common thread—selection
Without a selection, any changes you apply are made to the
whole image For example, if you choose to paint a black
stroke, you would select the Paintbrush tool, choose the color
black, and begin painting Photoshop will let you apply black
paint to any and all portions of the image Selections are
your way to instruct Photoshop what portions of the active
document you want to change and which you want to protect
from change
The Marquee tools are considered Photoshop's "good
old" selection tools In fact they've been a part of Photoshop
since the early days Where the marquee tools let you select
areas of an image in a structured way (using squares, circles,
lines), the lasso tools add a bit of freeform selection to the
mix Lasso tools require a certain amount of hand/eye
coordi-nation For example, you can use the lasso tool to create a
customized selection area around just about any object in a
document, be it an animal, vegetable, or mineral It just
requires a good eye, a steady hand, and a really big mouse
pad (I hate it when I run out of mouse pad)
Creating a selection lets you influence a specific area of
the image For example, If you are changing the color of a car
from red to blue, this is where making a selection really
shines When you select an area of a Photoshop document,
the selection becomes the work area—filters, adjustments,
and brushes will only work within the selection boundary
Since selection is such an important aspect of controlling
what happens in a document, Photoshop gives you many
ways to create your desired selection Mastering the art of
selection gives you control over not just what you do, but
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What You’ll Do
Use the Rectangular Marquee Tool Use the Elliptical Marquee Tool Use the Single Row and Single Column Marquee Tools
Use the Lasso Marquee Tool Use the Magnetic Lasso Tool Use the Polygonal Lasso Tool Use the Quick Selection Tool Use the Magic Wand Tool Select by Color Range Refine a Selection Edge Add, Subtract and Crop a Selection Use Channels to Create and Store Selections
Modify an Existing Selection Copy and Paste a Selection Use Free Transform and Transform Use Puppet Warp
Use Content-Aware Fill and Scaling
Trang 2The Rectangular Marquee tool lets you create rectangular and square selection marquees The Rectangular Marquee tool is excellent for a quick crop, or selecting and moving blocks of image information Select the Rectangular Marquee tool on the toolbox from the available Marquee options, and then drag the tool using the mouse (or drawing tablet) to control your movements To further control a selection, hold down the Shift key to produce a perfect square, and hold down the Alt (Win) or Option (Mac) key to create a selection marquee that starts from the center and moves outwards Releasing the mouse instructs the Rectangular Marquee tool to create the selection
Using the Rectangular
Marquee Tool
Use the Rectangular
Marquee Tool
Select the Rectangular Marquee
tool on the toolbox
Click the Tool Preset list arrow,
and then select from the available
tool presets
Use the selection options on the
Options bar to create a new
selection, or add to, subtract from,
or intersect with an existing
selection
Enter a numerical value (0 to 250)
in the Feather box to create a
feathered selection edge or click
the Refine Edge box to visually
fine-tune your feather size
Click the Style list arrow, and then
select from the available styles:
◆ Normal Lets you create
freeform rectangular, or square
marquee selections
◆ Fixed Ratio Lets you create
selections using a specific
ratio, such as a 2 to 1 ratio
Enter the Fixed Ratio values in
the Width and Height boxes
◆ Fixed Size Lets you create
selections based on an
absolute size such as 30 pixels
by 90 pixels Enter the Fixed
Size values in the Width and
Height boxes
Drag the selection area you want
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Selecting Areas for a Standard Monitor
If you are selecting areas of an image and plan to display them on a standard monitor (not DVD), then click the Fixed Aspect Ratio option
on the Options bar, and then enter a width value of 4, and a height value of 3 Since a normal computer monitor (regardless of resolu-tion) has a 4 by 3 ratio, then the selection you make will fit a com-puter monitor perfectly
For Your Information
Trang 3Using the Elliptical
Marquee Tool
Use the Elliptical Marquee Tool
Select the Elliptical Marquee tool
on the toolbox
Click the Tool Preset list arrow,
and then select from the available
tool presets
Use the selection options on the
Options bar to create a new
selection, or add to, subtract from,
or intersect with an existing
selection
Enter a numerical value (0 to 250)
in the Feather option to create a
feathered selection edge or click
the Refine Edge box to visually
fine-tune your feather size
Select the Anti-alias check box to
create a softer selection
Click the Style list arrow, and then
select from the available styles:
◆ Normal Lets you create
freeform elliptical or circular
marquee selections
◆ Fixed Ratio Lets you create
selections using a specific
ratio Enter the Fixed Ratio
values in the Width and Height
boxes
◆ Fixed Size Lets you create
selections based on an
absolute size Enter the Fixed
Size values in the Width and
Height boxes
Drag the selection area you want
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The Elliptical Marquee tool lets you create oval or circular selection marquees When used with the Layer Mask option, and a couple of creative filters, you can create some awesome vignettes Select the Elliptical Marquee tool on the toolbox from the available Marquee options, move into the document, and then drag with the tool using the mouse to control your movements To further control a selection, hold down the Shift key to produce a perfect circle, and hold down the Alt (Win) or Option (Mac) key to create a selection marquee that starts from the center and moves outwards Releasing the mouse instructs the Elliptical Marquee tool to create the selection
Trang 4The Single Row/Single Column Marquee tools let you create a 1-pixel wide horizontal or vertical selection Select the Single Row or Single Column Marquee tool on the toolbox from the available Marquee options, and then click the tool within the active document to create a single-pixel horizontal or vertical selection To move the selection, place your cursor on the selection; when you see the cursor change to
an arrow, then click and drag Release the mouse when you have the selection correctly positioned For precise positioning, press the arrow keys to move the selection 1 pixel at a time
Using the Single Row
and Single Column
Marquee Tools
Use the Single Row and Column
Marquee Tool
Select the Single Row Marquee or
Single Column Marquee tool on
the toolbox
Click the Tool Preset list arrow,
and then select from the available
tool presets
Use the selection options on the
Options bar to create a new
selection, or add to, subtract from,
or intersect with an existing
selection
Drag the selection area you want
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Single row Single column
Did You Know?
The Column Marquee tools don't have
an Anti-Alias option The reason is that
a monitor displays digital information
using pixels Since the pixels fit
together just like bricks in a wall, and
the Column Marquee tools can only
draw vertical or horizontal lines, there
is no need to make them look smoother
because they're following the
horizon-tal and vertical lines of the pixels
Creating Customized Guides
Have you ever needed a 45-degree angled guideline? Create a new layer, select the single row (or column) marquee tool, and then click
to create a selection in the active document Now, select black (or any other color) and press Alt+Backspace (Win) or Option+Delete (Mac) to fill the 1-pixel selection with the default color Click the Edit menu, point to Transform, and then click Rotate Enter a value of 45
in the Angle option on the Options bar and then you'll have an instant 45-degree guide Since the guide is in a separate layer, you can use the Move tool to reposition it anywhere it's needed
For Your Information
Trang 5The Lasso Marquee is a freeform tool that requires a bit of hand-to-eye coordination Select the Lasso tool on the toolbox from the available Lasso options, move into the active document, and then drag the tool, using the mouse (or drawing tablet) to control your movements Hold down the Alt (Win) or Option (Mac) key, and then drag to draw straight-line segments Releasing the mouse instructs the Lasso tool to close the selection shape That's all there is to it I did mention that it requires good hand-to-eye coordination, didn't I? When you use this tool, don't drink too much coffee, and have a really big mouse pad
Using the Lasso
Marquee Tool
Use the Lasso Marquee Tool
Select the Lasso tool on the
toolbox
Click the Tool Preset list arrow,
and then select from the available
tool presets
Use the selection options on the
Options bar to create a new
selection, or add to, subtract from,
or intersect with an existing
selection
Enter a numerical value (0 to 250)
in the Feather box to create a
feathered selection edge or click
the Refine Edge box to visually
fine-tune your feather size
Select the Anti-alias check box to
create a softer selection (useful
with intensely rounded or curved
selections)
Drag the selection area you want
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Did You Know?
You can temporarily convert the Lasso
tool into a straight-line drawing tool
(called the Polygonal Lasso tool) Hold
down the Alt (Win) or Option (Mac)
key, then release the mouse, move to a
different area of the document window
and click to draw a straight line
between the two points
Trang 6The Magnetic Lasso creates a selection by following along the edge of
a visible object For example, it will follow around the edge of a building set against a bright blue sky In reality there are no edges in a photo-graphic document, so the tool follows along the shifts of brightness created when one tonal value is next to another Select the Magnetic Lasso tool in the toolbox from the available Lasso options Click on the visible edge of an object within your image, and then move (don't drag) around the object The Magnetic Lasso will follow the visible edge of the object, occasionally adding anchor points to the line as you move
Double-clicking the mouse instructs the Magnetic Lasso tool to close the selection shape
Using the Magnetic
Lasso Tool
Use the Magnetic Lasso Tool
Select the Magnetic Lasso tool on
the toolbox
Click the Preset Tool list arrow,
and then select from the available
tool presets
Use the selection options on the
Options bar to create a new
selection, or add to, subtract from,
or intersect with an existing
selection
Enter a numerical value (0 to 250)
in the Feather box to create a
feathered selection edge or click
the Refine Edge box to visually
fine-tune your feather size
Select the Anti-alias check box to
create a softer selection (useful
with intensely rounded or curved
selections)
Enter a Width value (0 to 256) to
instruct the Magnetic Lasso tool
how many pixels to consider for
the edge
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Trang 7Enter an Edge Contrast value
(0% to 100%) to instruct the
Magnetic Lasso how much of a
shift in the brightness values to
use in determining the edge
Enter a Frequency value (0 to 100)
to instruct the Magnetic Lasso
where points are added to the
selection line
Click once to create an anchor
point, and then move the pointer
along the edge you want to trace
If the border doesn't snap to the
desired edge, click once to add a
anchor point manually Continue to
trace the edge, and add anchor
points as needed
Double-click or click the starting
point to complete the selection
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Magnetic Lasso selection
Did You Know?
You can remove anchor points When
you're using the Magnetic Lasso tool
and you want to reverse the selection,
simply backtrack the mouse all the way
back to the last anchor point To move
even farther backwards, press the
Backspace (Win) or Delete (Mac) key
to remove the last anchor
You can temporarily use the Magnetic
Lasso tool as a freeform Lasso tool
Hold down the Alt (Win) or Option
(Mac) key, and then drag to draw
Release the mouse to return to the
Magnetic Lasso tool