Selections: Limiting the Damage

Photoshop possesses many tools for designating which pixels in a document are affected by the next action performed. Since pixels can be partially selected, selections can also designate how affected those pixels will be.

The steps are almost always the same:

• Make a selection with one of the tools discussed on the following pages.
• Refine that selection, if necessary.
• Perform some task, often resulting in a mask that reveals the result where desired and hides it elsewhere.
• Refine the mask, if necessary.

Selection Tools

Picture or recall a stencil. It could be made of cardboard or plastic and has carefully shaped holes in it. When used with an imprecise tool (a can of spray paint, for example), it creates a result as precise as the holes cut into the stencil. Our selections are very similar. We designate one or more areas (corresponding to the stencil’s holes) that will be affected when we apply a potentially imprecise tool, such as the Brush tool.

As software, we can have shockingly intricate selections that push the stencil metaphor to the edge of usefulness. When areas are partially selected, that metaphor is undone. (A porous stencil?)

Let’s have a look at the different tools and methods available to isolate parts of images and our actions on them. The next section then covers modifying and combining selection tools by adding to and subtracting from selections and more.

Marquees

There are four tools in this set: Rectangular, Elliptical, Single Row, and Single Column Marquee tools. The first two of these get regular use and are accessed by the letter M (use Shift-M to toggle between them). With either, drag diagonally to create a selection (upward or downward, left or right). Use Shift to constrain the shape to a square or circle. Modifying with the option/Alt key causes the selection to grow from its center. You can use both modifier keys to both constrain and center the selection.

Single Row or Single Column marquees are created with a single click and will span the entire canvas in one direction, but will be only one pixel high or wide, depending on which tool you’re using.

Lassos

There are three tools in this set, but only two are worth using. The Lasso tool allows you to draw the shape of your selection in a freehand manner. If you don’t complete a closed shape while drawing, Photoshop will close it with a straight line between where you release and where you began.

Use the Polygonal Lasso tool by clicking where you want the vertices of a polygon-shaped selection to be. Double-clicking a distance from your starting point will close the selection with a straight line.

The maddening Magnetic Lasso tool attempts to conform the growing selection to edges it detects near the cursor as you drag. It finds the edges you’d like it to and many others as well. The newer Quick Selection tool (discussed below) is far faster and more reliably finds edges.

Magic Wand

This venerable tool is hidden by newer ones: the Object and Quick Selection tools. Right-click on whichever is shown in the Tools panel to get to the other. The Magic Wand tool has been in Photoshop since its beginning. You might call it the “elder wand.”

This tool utilizes a Tolerance setting you choose in the Options Bar. When you click a pixel in the image, the Magic Wand tool reads or “samples” its color, then grows a selection of similar colors from that point outward. The Tolerance determines what constitutes “similar.” The algorithm is interestingly complicated. In some contexts, the Tolerance number is simply the range of levels (shades of gray) on each channel around the levels of the pixel clicked. In other contexts, it’s more sophisticated. With use, it becomes more intuitive and you’ll learn to adjust this setting in small increments.

You can also adjust the precision of the sampled color. In the Options Bar or by right-clicking on the image, you can choose the area sampled (Sample Size). The default is a single pixel. I like to enable caps lock on my keyboard to engage Photoshop’s precise cursors when I choose that setting. It shows a crosshair that helps me click on exactly the right pixel. Other settings average areas of nine pixels (3 by 3) up to over ten thousand pixels (101 by 101). The standard wand cursor is fine for those.

Warning: Almost all tools that sample color (including various eyedroppers throughout the program) will be affected by the Sample Size choice.

Also by default, the Magic Wand tool selects contiguous pixels, ignoring similar ones that are separated from the sample by an area of dissimilar color or tone. In the Peachy example, selecting the black velvet left the black parts of the eyes unselected. Uncheck the Contiguous checkbox in the Options Bar to change this behavior.

Quick Selection

This tool is a smarter, edge-detecting version of the Magic Wand tool. You sample an area with its brushlike cursor. From this, Photoshop learns the color, texture, tone, and proximity you’re trying to select. From your initial brush stroke, the selection grows to include pixels that share those attributes, stopping at detected edges.

You can increase the sample area by using a larger brush size (adjusted with the [ and ] keys) and/or making a larger brush stroke. Be wary, however, since this also makes Photoshop a little more aggressive in its selection making. I recommend smaller brush sizes and more numerous short brush strokes. After the first stroke, this tool is automatically in an additive mode without needing to use the Shift key.

Also, since the program is learning from you, prevent the edges of the brush from crossing the edges of what you’re trying to select. If this happens, undo that step rather than trying to remove those pixels from the errant selection.

If, on the other hand, Photoshop overshoots those edges on its own, you can correct it by holding down option/Alt and carefully brushing over the undesired areas to subtract them from the selection. This improves its learning. In other words, undo your mistakes, and gently correct Photoshop’s.

Object Selection

Think of this as a guided Select Subject (see below). Use it like the Rectangular Marquee tool or the Lasso tool (choose in the Options Bar) to snugly surround a subject, then Photoshop will attempt to refine the selection to that subject. Holding down option/Alt, you can surround regions that should be removed from a selection.

Select Subject

Available from Select > Subject or a button in the Options Bar when the Magic Wand, Quick Selection, or Object Selection tool is active, this function analyzes the image for a likely subject and selects it! Introduced in the 2019 release and redeveloped extensively for 2020, this method should be tried before manual methods. If it fails, we still have all the other methods. Be sure to use this method again whenever Photoshop updates, as it may then do a better job.

Quick Mask: Previewer & Helper

Quick Mask is an old method of previewing and, less often these days, adjusting selections. When I have an especially intricate or convoluted selection, Quick Mask helps me see just what is and isn’t selected. You enter this mode by tapping the letter Q on the keyboard, clicking the Quick Mask button near the bottom of the Tools panel (), or choosing Select > Edit in Quick Mask Mode. When you do any of these things, the Quick Mask button inverts (); the active layer’s highlight color changes; and, if there’s an active selection, the “marching ants” disappear, leaving a color overlay over the nonselected areas of the image:

When this mode is active, a temporary channel is created and made active. This is similar to “Saving & Loading Selections” (page 283) except that a Quick Mask channel disappears when the mode is left.

All channels are grayscale images and can be edited as such: you can paint or perform tonal adjustments on them, for example. When viewed alone, a channel indeed looks grayscale. But when you simultaneously view both the standard color channels (RGB) and one of these extra channels, like Quick Mask’s, the black of that channel is replaced with a translucent color so you can see it overlaid on the image. In this case, that color is usually red, but it can be changed by double-clicking the Quick Mask button. You can also choose to change its opacity and whether the color overlays the selected area or the nonselected or “masked” area.

When you paint on a Quick Mask with white, you are effectively adding to what’s selected. Black adds to what is masked. Blurring a Quick Mask makes the edges semi-selected like the Select > Feather… command. Painting with a soft brush or with shades of gray will also make areas partially selected.

Some users who regularly need painterly selections set their Quick Mask Options to have color indicate Selected Areas. When they need to paint a selection, they tap Q (with no preliminary selection), then start painting. When they hit Q again, they have a selection with the qualities of their paint strokes.

This ability to paint a selection has found its way into “Select and Mask: Make or Refine Selections” (page 274). Using a Quick Mask-like preview can be found there and with the other selection methods that follow. Readers interested in the historical analogs to Quick Mask should search for information on “rubylith” in the fields of graphic design and lithography.

Color Range

Color Range is a dialog box with several tools and selection previews that help us to isolate areas based on their color. As the name implies, our objective is to define the range of color we want to select.

Choose Select > Color Range to start the process. Ignore the dialog’s initial preview, as it assumes, usually incorrectly, that we’re trying to select Foreground Color pixels. Luckily, we can use the already-active eyedropper sampler to click in the image to specify a starting point for the color range’s definition. If you want to exclude a range of color from your selection (like a blue sky behind a subject you want to select), check the Invert checkbox.

The Add to Sample tool (eyedropper with a plus sign in the Color Range dialog) extends the range to include more colors. The Subtract from Sample tool is not as good at its job as its companion, however. Thus I try to avoid needing it!

At the top is a menu (Select) of predefined hues and tones. These achieve mixed results. In that menu is Skin Tones, which activates the Detect Faces checkbox. For quickly selecting different parts of the tonal range (rather than a color range), you can choose Highlights, Midtones, or Shadows, which can be fine-tuned with the Range slider.

You can use the Fuzziness slider to narrow or expand the range of Sampled Colors, which is the most useful choice. I usually set this to a low value, use the Add to Sample tool, and then adjust Fuzziness as needed.

To keep the selection closer to where you clicked to sample colors, check Localized Color Clusters. The Range slider then becomes active so you can control just how close to your samples the selection will be.

While monitoring your progress, the preview in the dialog will become frustratingly small. Use the Selection Preview menu to choose different ways of using the main image window as your preview. Grayscale will show the selected areas in white (or gray for partially selected areas), and the excluded areas in black. White or Black Matte cover the excluded pixels in white or black, leaving the selected areas in their own color. Quick Mask is a translucent, matte red by default. See “Quick Mask: Previewer & Helper” (page 271) for more about this selection-viewing aid. To recall what the image actually looks like while working, hold down command/Ctrl or choose Image below the preview in the dialog box.

Finally, if you anticipate needing to select similar ranges of colors in other images, you can use the Save… button to create a file that can later be loaded via the Load… button.

Focus Area

This function analyzes the image to select what’s “sharp,” or in-focus. To access this function, choose Select > Focus Area. At first, Photoshop automatically tries to determine a range of sharpness (the In-Focus Range), but you can adjust this parameter to tighten or loosen its constraints. If areas are either overlooked or mistakenly included, you can use the Focus Area Add and Subtract tools. These are just versions of the Quick Selection tool embedded in this dialog box. Since noise in an image can influence the analysis of what is sharp or blurry, the so-called Advanced section has an Image Noise Level slider. Raise this if noisy but blurry areas are being included in the selection.

The View and Output To choices that are included in this dialog are also in the Select and Mask workspace (discussed next). In fact, there’s a button to make the hand-off to that workspace easier if it’s needed. The choices in the View menu help you to differentiate the selected area from masked areas. Output To can save you a later step, especially if that was to make a layer mask from the selection you’re making with this dialog.

Select and Mask: Make or Refine Selections

This is an entire workspace dedicated to the task of making selections. For that reason, you sometimes hear it referred to as a “task space.” Access it by using the shortcut ⌘-option-R/Ctrl-Alt-R or by pressing the Select and Mask... button in the Options Bar when any selection tool (and a layer) is active.

In the Select and Mask workspace, you’ll find several of the tools discussed on the previous pages: the Lasso and Polygonal Lasso tools, the Quick Selection tool, the Object Selection tool, as well as a simple Brush tool that paints a selection much like it would in Quick Mask mode. When using any of these, holding down option/Alt will remove areas from the selection as you’d expect.

This environment used to be called Refine Edge, and I still use it most often to refine rather than create selections. It seems that with each version, the differences between Quick Selection tools inside Select and Mask and outside are diminishing. But be aware that small differences remain, so if you are displeased with the result of the one inside, you may wish to try the other, and then only refine in Select and Mask.

Select and Mask Views

With some selections, especially complex ones or those with soft, delicate edges, it can be hard to tell how good of a job you’re doing. Luckily, we can choose from seven different views. Each can be accessed from the View menu or via a shortcut key. Be aware that dialog boxes and task workspaces like Select and Mask often have shortcuts for their specific functions, but those same shortcuts will do other things in the rest of the program. So, to access the default View called Onion Skin, you can tap the O key. (In case you’re curious, the tools this shortcut accesses outside this workspace are very nearly useless: the Dodge, Burn, and Sponge tools.)

Onion Skin (O) Makes unselected areas of the active layer translucent, showing any layers below the active one. This is the default View. Adjust the Transparency slider for greater contrast between selected and masked (unselected) areas.

Marching Ants (M) Just the regular marquee. It’s nice to have the old nickname for it made official. This offers no way to tell if areas are less than half selected, as the marquee is not drawn for them.

Overlay (V) This is Quick Mask with another name. You can adjust its opacity, color, and where it’s displayed (selected or masked areas). See “Quick Mask: Previewer & Helper” (page 271) for more.

On Black (A) This mode is good when your subject was originally surrounded by light pixels. You can adjust the Opacity of this black matte.

On White (T) This mode is good when your subject was originally surrounded by dark pixels. You can adjust the Opacity of this white matte.

Black & White (K) Shows the selection as a mask with shades of gray indicating levels of selectedness. White is used for fully selected areas, and black for areas not selected at all. If the goal for your selection is a layer mask (as most are), this shows you exactly what that mask will look like. I like the clarity of this View when my image is visually busy and the selection is complex.

On Layers (Y) This View is especially useful when your objective is making a layer mask. You can develop your selection seeing exactly what the result will be.

Select and Mask Global Refinements

These four sliders change the character of the selection’s edge. Note that the last one, Shift Edge, is dramatically affected by other settings, and thus should be tweaked after all else.

In these examples, I chose the Black & White View to better show the character of the edges.

Smooth I suggest thinking of smooth as sanding. The selection edge will be less rough, but may retain some of its softness (blurriness or ambiguity).

Feather This refinement literally blurs the selection.

Contrast This is the opposite of Feather, in a way. Rather than add shades of selectedness at the edges, as Feather does, Contrast reduces those shades. At 100%, areas are either selected fully or not at all.

Shift Edge This refinement is the trickiest. The distance the selection edge is “shifted” depends on its softness: +100% extends the selection to its wispiest outer edges, whereas −100% pulls it in to its most solidly selected areas. With a sharp-edged selection, a −30% Shift Edge will be imperceptible, but if you use a high Feather value, that amount may be significant. The Edge Detection Radius can also amplify this refinement’s effect. That is why I recommend saving this refinement for last.

Edge Detection and Refinement

The real power of this workspace is Edge Detection. This powerful refinement relies on the concept of a Radius, a (usually) narrow band straddling the selection’s edge. Below, a Radius setting of 23 px causes Photoshop to scrutinize an area 56 pixels wide, centered on the edge of the current selection.

When you check the box for Smart Radius, the area under scrutiny narrows a bit as Photoshop works even harder to discern finer edge details in the image. If you’re curious about just where Edge Detection is taking place, check the Show Edges checkbox at the top of the View Mode section, as I did for the image above. Remember to disable this again so you can see the actual selection edge.

The Radius setting is great for edges that have a small amount of fuzziness to them, like wool sweaters, facial stubble, or plush fruit. But when wispy details like long hair are present, especially in some areas but not others, you need to use the Refine Edge Brush tool. Paint with it to indicate where to use Edge Detection. Its remove mode is useful if you make a mistake.

The Refine Edge Brush tool is best used by brushing outward from fully selected areas to include parts of the image where delicate details are entangled with unwanted pixels. When hair is involved, my motion is similar to actually brushing hair. Remove areas from edge detection by option/Alt painting. This is an amazing function, but residue is sometimes left behind.

Any colors that were behind the subject we selected will likely be entangled in the pixels at the edges—that is, right where we are doing edge detection. In this example, some gray still contaminates the hair. In the Select and Mask Output Settings section, we can check Decontaminate Colors. This finds the colors within the selected subject nearest our edge-detection zone (set by the Radius slider and our Refine Edge Brush tool brush strokes). With those colors, this checkbox essentially recontaminates those edges so they can be placed in front of any backdrop.

Since adding color to an image can be considered destructive, choosing to Decontaminate Colors changes the setting of the Output To menu too. Photoshop creates a duplicate layer with a layer mask that hides the effects of adding colors to the edges. The original layer is still present, but its visibility is turned off.

To finish such a composite, we usually need to add adjustments or other effects to better match lighting between the elements. For this image, I added one adjustment to the image of the woman to increase its contrast and warm it to match the Arizona scene. I also blurred that backdrop to have the composite better match the focus of the photo of the woman. Finally, as always, I did a little touch-up on the layer mask made by the Select and Mask process, trimming a few hairs here and there.

Other Selection Modifiers

While most modifications to a selection can be achieved through the Select and Mask task space, there are a few menu-driven methods to mention.

To invert a selection (selecting what’s not selected and deselecting what is), use Select > Inverse.

The Select > Modify menu has a few choices too. Border… transforms an area selection into a narrow band of selection as wide as you designate in its dialog box. Expand… and Contract… grow or shrink a selection by precisely the number of pixels you specify. Both of those as well as Feather… and Smooth… can be accomplished more visually in Select and Mask.

Select > Grow and Select > Similar use the Magic Wand tool’s Tolerance setting to expand a selection to include more pixels like those already selected. Grow will add only pixels contiguous to the selection, whereas Similar selects similar colors throughout the image.

Finally, you can use Select > Transform Selection to manipulate a selection in a way similar to “Free Transform” (page 332).

Combining Selection Tools

Once you’ve created a selection (and there’s a marquee in your image), you can alter it with any of the tools you’d use to create a selection. Holding down the Shift key will cause a plus sign (+) to appear next to the cursor, indicating that you’re adding to the existing selection.

Holding the option/Alt key reveals a minus sign (–) so you can remove pixels from the current selection.

Holding both those keys (shift-option/Shift-Alt) will leave selected the intersection (overlap) of the existing selection and the one made while holding those keys.

Earlier, I mentioned what these keys do when you’re first making a selection (constraining or centering the selection). Achieving both results with these keys is slightly difficult. For example, to add a perfectly circular area to an existing selection, you must be holding down the Shift key as you begin dragging with the Elliptical Marquee tool. While still dragging, you must temporarily release and then again hold down the Shift key to indicate you want a circle (constrained ellipse), and then keep the Shift key depressed as you complete the selection.

The Quick Selection tool automatically enters a mode that adds to an existing selection once you start a selection with it. The Options Bar for each tool also contains buttons for adding, subtracting, and (for most) intersecting with an existing selection.

Color Range intersects its result with an existing selection.

Saving & Loading Selections

The Quick Mask feature uses a temporary channel to help us visualize and even edit a selection as a grayscale image. We can create a more enduring version of this by saving a selection. When an active selection is saved, a new channel, called an “alpha channel,” is made below the channels that control color (RGB or CMYK, etc.). Usually, white is used for the selected areas, black for masked, and shades of gray for soft selection edges. Later, that alpha channel can be loaded as a selection again or used by certain filters (e.g., Lens Blur) to affect specific areas of an image.

To save a selection, you can choose Select > Save Selection…, after which a dialog box with options appears, or you can click the Save selection as channel button () at the bottom of the Channels panel. In the latter case, the channels will be automatically named “Alpha 1,” “Alpha 2,” etc. Hold down option/Alt when clicking the Save selection as channel button to choose a name for the channel.

With the Select menu method, you can choose a name, the document in which the channel is added, and how/whether the selection affects other alpha channels. In the Save Selection dialog, you may choose to save the selection to another document with the same pixel dimensions or create a new document. The latter will contain no channels other than the alpha channel, in essence making it a grayscale document. This procedure is useful for features that use such documents as “maps.” Photoshop’s 3D features, for example, can use these documents’ shades of gray to show where a texture is metallic, rough, or transparent.

If the Destination Document has alpha channels already, you can choose one from the Channel menu. If you do, all four choices in the Operation section of the dialog become available. The default is to create a New Channel, but when you choose an existing channel, this becomes Replace Channel. The other operations are similar to those discussed in the previous section, “Combining Selection Tools” (page 282). These operations can also be performed when loading a selection.

To load a saved selection, you can choose Select > Load Selection…. The Load Selection dialog box has similar choices as saving: from which document and channel should the selection come, and how should it interact with a live, existing selection if one exists.

It’s in loading selections that I usually leverage the choices of Operation. When I save selections, I sometimes have a look at them to do a little cleanup by painting with white or black. In retouching and color correction workflows that involve teams, some individuals are tasked with creating these channels so experts at color correction can follow them without having to make the selections.

A faster way to load a channel as a selection is to click on the channel while holding down the ⌘/Ctrl key. As you hover over a channel with that key held, you’ll see a hand cursor with a small marquee on it (like the one at right). If you have an existing selection and hold down ⌘-shift/Ctrl-Shift, a plus-sign appears in that cursor, confirming that you’ll add that channel to the selection. ⌘-option/Ctrl-Alt removes the channel from the selection (minus sign appears in cursor), and ⌘-option-shift/Ctrl-Alt-Shift intersects the channel and selection (an “X” appears in the cursor).

You’ll find this works for layer content too! Use this method on a layer’s thumbnail to select a layer’s nontransparent content or a layer mask to load it just like any other channel.

Another advantage to this method is that you can load any channel as a selection, including the color channels. By ⌘/Ctrl-clicking the RGB composite channel, you are making a selection proportional to the luminosity in the image. That is, the lighter an area is, the more selected it will be. In the lingo of Photoshop old-timers, this is making a “luminosity mask.” Inverting such a selection favors the shadows. Either way, these are excellent selections from which to make adjustments that impact one end of the tonal range more than the other. See “Luminosity Masks” (page 288) for more.