In Animate, we were using tools to draw things. To select the thing we drew, all we had to do was click on it. In Photoshop, we often are working with image files such as .jpg or .png which are a collection of pixels so we can't just click on a portion of the image and thus select an object, and therefore how to do selections is important in Photoshop.
Working with Selections (Chapter 3, Adobe Photoshop Classroom in a Book - 2021 release)
About selecting and selection tools
Making changes to an area within Photoshop is a two-step process
- Use one of the selection tools to select the part of the image you want to change
- Use another tool, filter, or other features, to make changes, such as moving the selected pixels to another location or applying a filter to the selected area
There are four primary types of selections
- Geometric selections
- Rectangular Marquee tool
- Elliptical Marquee tool
- Single Row Marquee tool - 1-pixel high row
- Single Column Marquee tool - 1-pixel wide column
- Freehand selections
- Lasso Tool - freehand selection
- Polygonal Lasso Tool - sets anchor points in straight line segments
- Magnetic Lasso Tool - gives best results when good contrast exists between area you want to select and its surroundings
- Edge-based selections
- Quick Selection Tool
- Object Selection Tool
- Color-based selections
The Magnetic Lasso, Quick Selection, and Magic Wand Tools all utilize color differences in the image to make the selection
Download the 03Start.psd and 03End.psd files in the Lesson 3 folder in Course Documents and copy them to a folder for today. Open the files using Bridge and examine them. The challenge in this lesson is to arrange the elements in the 03Start.psd file into the page you see in 03End.psd. Double click the 03Start.psd file to open the image in Photoshop and then choose File>Save As, rename the file 03Working.psd.
Adding to or Subtracting from a Selection (couldn't find in text, see beginning of Adobe video on schedule page)
Use a selection tool (e.g. the Rectangle tool) and drag in the image to make a selection. You will see 4 groups of rectangles at the left of the options bar. Click the second group of rectangles and then drag another rectangle with the Rectangle tool - this adds to the selection. Then click on the third group of rectangles and drag another rectangle - this subtracts from the selection.
Instead of clicking the second group of rectangles you can hold down the Shift key when making the selection; instead of clicking the third group of rectangles, you can hold down the Alt key when you are making the selection.
The fourth group of rectangles provides the intersection of two selections; i.e. the area common to both.
Using the Magic Wand Tool
The Magic Wand tool selects all the pixels of a similar color. It is most useful for selecting an area of similar colors surrounded by areas of very different colors. When one selects the Magic Wand tool, the options bar provides several choices.
- Sample size: The default is "Point Sample". This means that the color used as the starting point is the pixel on which one clicked. The other choices use the average of several pixels surrounding where one clicked. If one has used the Eye Dropper Tool and set the point size there, the same choice will be the default for the Magic Wand tool.
- The default tolerance value is 32. Increasing the tolerance value will select more pixels as being similar to the color in the picture where one clicks.
- Select the Magic Wand tool, hidden under the Object Selection Tool (second column, second from top).
- In the options bar, confirm that the Tolerance value is 32.
- Click in the red background around the sand dollar.
- The red background is selected, but we want the shell, so we start over.
- Choose Select>Deselect.
- Position the Magic Wand tool over the sand dollar (the white object against the red background) and click.
- If some interior areas of the sand dollar show selection marquees, this is because their colors differ from the color you clicked by more than 32.
- Increasing the tolerance level can often solve this problem but in this case, increasing the sample size may also solve the problem depending on what sample size is chosen and where one clicks. Increasing the tolerance may solve the problem but it may also select some unwanted parts of the background. In this case, it's better to use a different tool, such as the Quick Selection tool, which is what we will do next.
- Choose Select>Deselect.
Using the Quick Selection tool
With the Quick Selection tool, you paint an area of an image and the tool automatically finds the edges; you then can add or select areas of the selection until you have what you want.
- Select the Zoom tool and then zoom in until you can see the sand dollar well.
- Select the Quick Selection tool in the Tools panel (second down in the second column, may be hidden under the Magic Wand tool.
- Click Enhance Edge in the options bar
- Click on an off-white area inside, but near the outside edge of the sand dollar.
- You can click or drag over areas you want to add to the selection. If you want to remove areas, hold down the Alt key while clicking or dragging.
Moving a selected area
Once you've made a selection, any changes you make apply exclusively to the pixels within the selection.
- Select the Move tool (top of first column).
- Drag the selected area up to the left area of the frame, which is labeled A in this picture. Position it over the target area, leaving the lower part of the target area showing as a shadow.
- Choose Select > Deselect or Ctrl+D (Ctrl and D at the same time) and then choose File>Save.
Note that in this case our starting file only has one layer so the pixels you move will replace the pixels underneath them.
Using the Object Selection Tool
- Select the Object Selection Tool, hidden underneath the Quick Selection Tool (second down from the top, second column)
- Draw a rectangle selection around the piece of coral (middle, bottom)- it should be a relatively tight selection with a small amount of space between the coral and the edges of the selection marquee.
- Select the Move Tool and move it to area B.
Most of the methods to manipulate selections work with any selection; in this section, we will use the Elliptical Marquee tool which enables you to select ovals or perfect circles.
Repositioning a selection marquee while creating it
Selecting ovals and circles can be tricky; it is not always obvious where you should start dragging; there are some keyboard-mouse combinations that can make repositioning selections much easier. If you accidentally release the mouse button at the wrong time, simply start the exercise again at Step 1.
- Select the Zoom tool - click the plate of shells (at the bottom left of the image) and zoom to at least 100%, or 200% if the entire plate will fit on your screen.
- Select the Elliptical Marquee tool (hidden under the Rectangular Marquee Tool, which is at the top of the second column).
- Move the pointer over the plate of shells and drag diagonally to create a selection but do not release the mouse button.
- Still holding down the mouse button, press the space bar and continue to drag the selection; instead of resizing the selection, you're moving it. Position it so that it more closely aligns with the plate.
- Release the space bar (but not the mouse button) and continue to drag to try to make the size and shape of the selection match the oval plate of shells as closely as possible. If necessary, hold down the space bar again to move the selection marquee around.
- When the selection border is positioned appropriately, release the mouse button
- Choose View>Fit on Screen or use the slider in the Navigator panel to reduce the zoom view so you can see all of the object in the image window.
Leave the selection active for the next exercise.
Moving selected pixels with a keyboard shortcut
- If the plate of shells is not still selected, repeat the previous exercise to select it.
- With the Elliptical Marquee tool selected in the Tools panel press Ctrl and move the pointer within the selection.
The pointer icon now includes a pair of scissors indicating that the selection will be cut from its current location.
- Drag the plate of shells onto the area of the shadowbox labeled "C"
- Release the mouse button, but don't deselect the plate of shells
Moving a selection with the arrow keys
Using the arrow keys moves the selection one pixel; holding down the shift key and using the arrow key moves the selection 10 pixels (similar to Animate).
You can hide the edges of a selection temporarily by choosing View > Show > Selection Edges. To redisplay them, choose View > Show > Selection Edges again to reveal the selection border again (this menu choice toggles between showing the edges and not showing them)
Choose Select>Deselect (or press Ctrl-D). Choose File>Save to save your work so far.
Softening the edges of a selection (skip)
To smooth the hard edges of a selection, you can apply anti-aliasing or feathering, or use the Select and Mask option.
Anti-aliasing smooths the jagged edges of a selection by softening the color transition between edge pixels and background pixels. Since only the edge pixels change, no detail is lost. To apply anti-aliasing, you must select it as an option in the options bar before making the selection. Anti-aliasing is available for the Elliptical Marquee, the Magic Wand, and the various Lasso tools.
Feathering blurs edges by building a transition boundary between the selection and its surrounding pixels. This blurring can cause some loss of detail at the edge of the selection. You can define feathering for the marquee and lasso tools as you use them, or can add feathering to an existing selection,
To use the Select and Mask option, first make a selection, and then click Select and Mask in the options bar to open its dialog box.
Selecting with the Lasso Tools
The Lasso tools have their "add" modes (holding down the Shift key or clicking the "Add to selection" pair of rectangles in the options bar) and "subtract" modes (holding down the Alt key or clicking the "Subtract from selection" pair of rectangles in the options bar) as with other tools.
The Lasso tools are often useful to cleanup a selection made with another tool, e.g. the Quick Selection Tool.
You can use keyboard shortcuts to move between straight-line (Polygonal Lasso Tool) and freehand (Lasso Tool) selections.
- Using the zoom tool, click the nautilus (the image at the bottom right) to zoom in to at least 100%.
- Select the Lasso Tool (first column, second from the top). Starting the the lower left, drag around the rounded end of the mussel. Do not release the mouse button.
- When you reach a corner or straight part of the edge, press the Alt key and then release the mouse button so that the lasso pointer changes to the polygonal lasso shape. Do not release the Alt key.
- Begin clicking around the end of the mussel to place anchor points - be sure to hold down the Alt key throughout.
- When you reach the top of the mussel, hold down the mouse button as you release the Alt key.
- Carefully drag around the tip of the mussel, holding down the mouse button.
- When you reach the bottom side of the mussel, first press the Alt key and then release the mouse button. Click using the Polygonal Lasso Tool
- Click the starting point of the selection and then release Alt. The mussel is now entirely selected. Leave it selected for the next exercise.
Rotating a Selection
- Choose View>Fit on Screen to resize the image to fit on your screen.
- Press Ctrl as you drag the selected mussel to section D. The pointer changes to the Move tool when you press Ctrl.
- Choose Edit>Transform>Rotate.
- Move the pointer outside the bounding box and then drag to rotate the mussel. Press Enter or Return to commit the transformation.
- If necessary, select the Move tool and drag to reposition the mussel, leaving a shadow to match the others. Choose Select>Deselect when you are finished.
Selecting with the Magnetic Lasso tool
You can use the Magnetic Lasso tool to make freehand selections of areas with high-contrast edges. The selection border will automatically snap to the edge between areas of high contrast. You can also control the selection path by clicking the mouse to place anchor points.
- Select the Zoom tool and click the nautilus (middle, top) to zoom in at least 100%.
- Select the Magnetic Lasso tool hidden under the Lasso Tool
- Click once along the left edge of the nautilus and then move the Magnetic Lasso tool along the edge to trace its outline.
- When you reach the left side of the nautilus again, double-click to return the Magnetic Lasso to its starting point and make the selection..
- Double click the Hand Tool to fit the image in the image window.
- Select the Move tool and drag the nautilus onto section E, leaving a shadow below it and on the left side
- Choose Select > Deselect, and then File > Save.
Selecting from a Center Point
In some cases, it is easier to make elliptical or rectangular selections by drawing a selection from an object's center point.
- Select the Zoom tool and zoom in on the screw - make sure you can see the entire screw head.
- Select the Elliptical Marquee tool.
- Move the pointer to approximately the center of the screw.
- Click and begin dragging, holding down the Shift key as you drag. Then without releasing the mouse button or the Shift key, press Alt as you continue dragging.
The selection is centered over its starting point.
- When you have the entire screw head selected, release the mouse button first and then release the Alt or Shift key.
- If necessary, reposition the selection using one of the methods you used previously. Do not deselect since you will use this for the next exercise.
Resizing and Copying a Selection
Resizing the contents of a selection
- Choose View>Fit on Screen
- Select the Move Tool
- Position the Pointer within the screw selection - the pointer now becomes an arrow with a pair of scissors, indicating that dragging the selection will cut it from its current location and move it to a new location.
- Drag the screw on to the lower right corner of the shadow box.
- Choose Edit > Transform > Scale.
- Press Shift as you drag one of the corner points inward so that it is small enough to sit on the frame. Press Enter or Return to commit the change.
- Use the Move tool to reposition the screw after resizing it.
- File > Save
Moving and duplicating a selection simultaneously
You can move and duplicate a selection at the same time.
- With the Move Tool selected, press Alt as you position the pointer inside the screw selection
The pointer changes, displaying the usual black arrow plus a white arrow right beside it, which indicates that a duplicate will be made when you move the selection.
- Continue holding down the Alt key as you drag a duplicate straight up to the right corner of the frame. Release the mouse button and the Alt key.
- Hold down Alt + Shift as you drag a new copy up to the left corner of the frame.
Pressing the Shift key as you move a selection constrains the movement horizontally or vertically in 45 degree increments.
- Repeat Step 3 to drag a 4th screw to the lower left hand corner of the frame
- Select>Deselect, and then File > Save.
Cropping an Image
You can use either the Crop tool or the Crop command to crop an image.
- Select the Crop tool - Photoshop displays a crop boundary around the entire image
- In the options bar, make sure Ratio is selected in the Preset pop-up menu and that there are no ratio values specified. Then confirm that Delete Cropped Pixels is selected.
When Ratio is selected but no ratio values are specified, you can crop the image with any proportions.
- Drag the crop handles so that the top half (where we have been moving things to) is the highlighted area; crop the area so that there is an even area of white around it.
- Click the Commit Current Crop Operation button in the options bar.
- File > Save.
Major Points of Chapter
- Selections allow you to make changes in part of an image, as opposed to the whole image
- There are many selection tools so use the right one for the job
- Selections take time (and patience) do things in a way that minimizes the need for them, e.g. by using layers (see Chapter 4)
Revised: October 28, 2021, 1:15pm. Comments to Bill Pegram, email@example.com