Selections and ChannelsOne of the primary features you use when editing and manipulating images are Selections . Selections are areas of an image you choose to isolate from the rest of the image to make modifications to or to copy and paste into other images or even the same image again. For instance, you might want to re-color someone’s eyes. To do so, you would use one of Photoshop ’s numerousSelection Tools and methods to isolate the area around the pupils on both eyes and make color adjustments accordingly. If you do not create a Selection then the entire image is affected by your color adjustments.
Selections are not saved by Photoshop automatically. For instance, having used the Selection Tools to isolate or select the color around the pupils of the eyes, and having made appropriate color adjustments, your client requests yet another change to the color. When you import or load your image into Photoshop again, you have to re-select the color around the pupils unless you tell Photoshop to save the Selection you have created. Photoshop saves Selections in Channels. Channels are part of the Layers Palette group. Be patient. We will get into Channels and how they operate further on in this chapter.
The Selection ToolsThe Marquee , the Move, the Lasso, the Magic Wand , the Pen Tool , and the Painting Tools in Quick Mask mode make up Photoshop ’s Selection Tools. A Marquee, a dotted line in constant motion, represents the shape of your selection. The Marquee is also known as aSelection path and informally as an “ant trail”. At any time, select Select/Deselect to remove a selection. We will examine how to use the Selection Tools and relatedPalettes.
Marquee Tool The Marquee Tool is used to create regular shaped selections. The shape of your selection is represented by a Marquee; a line of cycling black and white squares in constant motion. The Marquee is also known as aselection path. Available shapes include a Rectangular Marquee for square and rectangular Selections ,Elliptical Marquee for circular and oval Selections andSingle Row and Single Column marquee to select single rows or columns of pixels. To access the supplementaryMarquee Tools you simply {Click} and hold your mouse button on the Rectangular Marquee Button in the Toolbox. A Fly-Out Menu appears giving you access to the rest of the tools.
To constrain the shape of the rectangular, elliptical or crop Tools hold the [SHIFT] key as you {Click} and drag to create your Selection. Perfectly square and circular selections result.
Crop Tool  Use the Crop Tool to cut all non-selected content from your image. This tool is very useful for tweaking the composition of a photograph as it allows you to remove extraneous material quickly and easily. The Crop Tool is limited to rectangular shapes.
Open the Photoshop file goldseal from the chapter006folder in photoshop6xfiles. Select the Rectangular Marquee . {Click} and drag a rectangular Selection over the circular emblem in the center of the image. Use theAirbrush Tool to paint over the image. You’ll notice that painting only occurs within the Selection area because the selection designates that this area, and only this area, is subject to modifications.
The Selection isolates a particular area
of the image. Modifications occur only to
the Selection area.
Use the History Palette to remove the modifications you’ve just done. Try out the other Shapes in theMarquee Tool.
When you get to the Crop Tool , you’ll notice boxes located at the corners of the Marquee as well as in the center of each side. You can {Click} and drag these to resize the selection path or marquee. Press [ENTER] on your keyboard to crop the image. What happens? The image data outside of the Crop Tool’s selection is erased and the image scales to the data within the selection. Notice that all material outside of the crop marquee has been grayed out so as to give you a better idea of how your content will look once it has been cropped. You can use the History Palette to restore the image back to its original state.
Multiple SelectionsYou may want to isolate more than one area of the image for modifications. To do so simply create your initial selection and hold the [SHIFT] key down as you create other selections. {Shift-Clicking} within a selection, adds to the selection.
Modifying Selections
You will have noticed that modifying or resizing the Crop Tool ’s selection path is easy. You simply {Click} and drag the square handles accordingly. To do the same to a regular selection select Select/Transform Selection. {Click} and drag to resize the Selection as you wish. Press [ENTER] to affect the changes. Press [ESC] to cancel the modifications.
The Info Palette{Click} the Info Tab in the Navigator Palette group.
Pass or roll the mouse pointer over the image. Notice that the Info Palette immediately returns information to you as you move your mouse around. As your mouse passes over part of the image data the Info Palette gives you RGB and CMYK (a color mode for Print) information, as well as the location of the pointer within the image, expressed in terms of X and Y coordinates in pixels (if you selected “pixels” as your base unit of measurement in File/Preferences /Units & Rulers .) You’ll notice aWidth(W) and Height (H) indicator in the bottom right corner of the Info Palette. This returns the dimensions of your selections. Make a Rectangular selection anywhere within the goldseal image. You’ll notice the Info Palettereturns the width and height values of the Selection in pixels. You can use the Info Palette when creating selections for precise measurements and accuracy.
Moving SelectionsTo move a Selection around the image simply {Click}within the Selection you have created and drag.
In addition to using the Move Tool to move the Toolbox ,Palettes, and Images around the Photoshop workspace, you can also use the Move Tool to move selections. Any image data within the Selection area moves with the selection.
To move only the Selection Marquee , not the image data within it, make sure you have any one of the Selection Tools selected in the Toolbox and {Click} inside a Selection area, hold, and drag the Selection.
The Lasso Tools{Click} and hold down on the current Lasso Tool in theToolbox to view the fly-out menu.
Lasso Tool The Lasso Tool is used to create irregularly shaped Selections . The Lasso Tool includes the Lasso for freehand Selections, similar to drawing with the mouse as you would with a pencil on paper. {Click}, hold and drag to create your Selection. {Release} the mouse button to close the Selection.
Polygonal Lasso Tool
The Polygonal Lasso Tool is used to make Selections by drawing a series of straight lines to make a polygonal shape. {Click} within the image to start or begin creating your Selection. As you drag the mouse (having released the button) a line extends from your start point. To begin another line {Click} again and continue until you have created the desired Selection shape. To close a PolygonalSelection either {Click} the start point again or {Double-Click} to make Photoshop draw the final line to the start point for you.
Magnetic Lasso Tool The Magnetic Lasso Tool works similarly to the PolygonalLasso Tool in that you {Click} within the image to start or begin creating your Selection and drag the mouse (having released the button) to create the Selection path. However, whereas with the other Selection Tools you determined the path or shape of your Selection, theMagnetic Lasso attempts to create the path itself. You act as a guide by directing the Lasso around or close to the area you desire to select.
Open the file fudog from the chapter004 folder. Select the Magnetic Lasso Tool and {Click} on one side of the statue. Begin to guide the mouse pointer along the side of the statue. You’ll notice that the path automatically snaps to the edge of the statue. The Magnetic Lasso uses color contrast to decide where to create the Selection path or shape. To increase the Magnetic Lasso’s accuracy{Click} frequently as you guide the Lasso. Click points, represented by small boxes, become visible along the selection path. To close the Selection path {Click} again at the start point or {Double-Click} to make Photoshop close the Selection for you. Presently, just select the head of the dog statue. Use the Move Tool to move your Selection to the left of the statue. Select Select/Deselect to remove the Marquee or Selection path that surrounds your Selection. You’ll see that an accurate copy of the top of the statue has been made. Notice that the current Background Color fills the Selection area when you move it. To increase accuracy you could use the Magnification Tools or you can modify the behavior and sensitivity of the Magnetic Lasso by modifying the parameters in the Options Bar.
Having used the Magnetic Lasso Tool to isolate the
top of the statue, use the Move Tool to move
the Selection to another area of the image.
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Selection Tool OptionsAs you know, the Options Bar displays a number of different options depending on the Tool you are currently using. All of the Selection Tools have a set of options, but some differ from others. The Magnetic Lasso has the most.
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FeatherFeathering your Selection creates a gradual softening effect, from solid color to transparency, similar to how the feathers on a bird’s wing gradually become transparent at the tips. To examine the effects of feathering select the Elliptical Marquee Tool . Before making a Selection of the top half of the statue, enter a value of 20 in the Feather field. Make sure Anti-alias edis checked. Recall that Anti-aliasing softens the transition from the edge of an image or Selection to the color the edge is placed against. Leave Style at default, Normal. Select the top half of the statue. Select the Move Tool and move your Selection toward the bottom of the image. You’ll notice the area you’ve moved the image data from fills with the current background color. You’ll also notice how the background color gradually fades or feathers into the surrounding color. Deselect your Selection. Notice how the edges feather into the background as well, becoming transparent toward the edge.
The effects of Feathering
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