Selection Tools in Photoshop

The basic selection tools include the marquee tools, the lasso tools, and the magic wand. However, we are also going to discuss many more ways of making and refining selections using Quick Mask Mode, alpha channels, and the transform selection command.

We use selections in Photoshop to isolate editing to specific areas in an image, or for cutting out portions of an image. Similarly, masks are used to protect specific image areas from being modified, or for removing portions of an image.

Marquee Tool:
Unless you're entirely new to Photoshop, you probably have some familiarity with the marquee selection tools. It's difficult to do much of anything in Photoshop without them. These include the rectangular marquee, the elliptical marquee, the single row horizontal, and single row vertical marquee tools.

The shortcut key for the marquee tools is M and Shift+M toggles the rectangular and elliptical marquee tools.

Let's look at some additional shortcuts for the marquee tools:

• Holding down the shift key while dragging a selection marquee constrains the selection to a square or circle.
• Holding down the shift key while dragging a selection marquee when an existing selection is active adds to the selection.
• Holding down the Alt/Option key while dragging a selection marquee when an existing selection is active subtracts from the selection.
• Holding down the Alt/Option key while dragging a selection marquee creates the selection from the center out from where you initially clicked.
• The Shift and Alt/Option modifier keys can be used together when making an initial selection to constrain proportions and draw from the center.
• The Shift and Alt/Option modifier keys can be used together when another selection is active to create a selection from the intersection (the areas where the two selections overlap).
• To reposition a selection while you are in the process of drawing it, hold down the spacebar. As long as the spacebar is held down you can move you selection, when you let up on the space bar you can go back to drawing your selection. The selection will not be finalized until you release the mouse button.
• You can move a selection after it has been finalized by moving the cursor inside the selection marquee as long as the marquee tool is active. The cursor will change to look like this and then you can click and drag the marquee into a new position. You can also use the arrows on your keyboard to reposition a selection.
• Ctrl/Command-A selects the entire image.
• Ctrl/Command-D removes the selection.
• Shift-Ctrl/Command-I inverts the selection.
• Ctrl/Command-H acts as a toggle to hide the marquee but preserves the selection.
  Notes for Version CS
  In Photoshop CS, you can also choose the add/subtract/intersect modifiers from the set of buttons on the options bar.
  The marquee tools have some options you can access in the options bar. You can adjust the feathering, anti-aliasing, and style.
• Feathering lets you fade the edge of the selection, but in most cases you will leave this setting to zero since there are more accurate ways of feathering a selection after it has been drawn.
• Anti-aliasing smoothes out the edges of the selection. You'll rarely, if ever, need to deactivate this. It will be unavailable for the rectangle selection tool because rectangles always have hard edges.
• The style menu lets you make more precise selections.
• When constrained aspect ratio is chosen you can choose the ratio of width to height. With both values set to 1 you would only be able to draw a perfect square or circle. With a width of 1 and a height of 2 you would create a selection that is two times higher than the width, and so on.
• When fixed width is chosen you can enter a width and height in pixels and just click once to make a selection of that exact size.
  Take some time now to try all these options using the marquee selection tools. When you're ready, continue on to the next lesson on the lasso tools.

Lasso Tool
The shortcut key for the lasso tool is L and Shift+L toggles between the three lasso tools.
The regular lasso tool allows you to make freehand selections. Just click and drag to draw the selection. Whenever you let up on the mouse button, your selection will automatically close, forming a straight line between the start and end points. The shortcuts for adding to and subtracting from the selection are the same as the marquee tools.

Here's some additional lasso tool shortcuts:

• If you want to draw straight lines with the lasso tool, you can hold down the Alt/Option key and make a series of single clicks instead of dragging.
• You can toggle between freehand and straight line mode by pressing the Alt/Option key while you are drawing the selection. This is a bit tricky, you need to make sure you press or release the key wile the mouse button is down or you will close the selection.
• You can hold down on the delete key to erase recently drawn line segments.
• You also have feathering and anti-aliasing options with the lasso tool.

Polygonal Lasso tool
The Polygonal Lasso tool is used to draw straight line selections. You can make the polygonal lasso tool work just like the regular lasso tool by holding down the Alt/Option key to draw freehand selection. One difference with the Polygonal lasso tool is that you can use the Shift key to constrain the selection lines to 45° increments. If you are drawing a straight line selection you can press the delete key at any time to remove the last segment. To remove multiple segments, press delete repeatedly.
If you used the polygonal lasso tool to make a freehand selection you can hold down the delete key to slowly erase the line. This also requires a bit of coordination, because you will have the Alt/Option key already held down to draw freehand. What you need to do is let up on the Alt/Option key and hold down delete. Then when you have erased as much as you'd like, you can go back to pressing down the Alt/Option key to continue your selection in freehand mode.

Magnetic Lasso tool
The Magnetic Lasso tool works similarly to the other lasso tools, but it has special powers that can detect areas of contrast and it will snap to the edges of the object you're trying to select. Because of these special powers, the magnetic lasso has more options than the other lasso tools.

You can temporarily switch to the regular lasso tool behavior while using the magnetic lasso by holding down the Alt/Option key and dragging. Or you can temporarily switch to polygonal lasso tool behavior by holding down the Alt/Option key and clicking. The Delete key allows you to delete points. Here's some additional lasso tool shortcuts that aren't mentioned in my tutorial:

• You can adjust the lasso width as you draw using the arrow keys or the [ and ] keys.
• You can adjust the frequency as you draw using the ; (semicolon) and ' (apostrophe) keys.
• You can adjust the edge contrast as you draw using the , (comma) and . (period) keys.

Closing selections with the polygonal lasso and the magnetic lasso is a little bit different than the freehand lasso tool. With these tools there's two ways to close the selection:

• If you move the cursor within a few pixels of the starting point, you'll see a tiny circle appear next to the cursor and it means that when you click once the selection will close.
• If you're not near the starting point and you want to close the selection you must double click.

If you're using the polygonal or magnetic lasso tool with the Alt/Option key to make freehand selections, you must let up on the Alt/Option key first, and then you can double click to close the selection.

Magic Wand tool
Last, but not least, is the Magic Wand tool. The magic wand makes selections based on color similarity. The shortcut for the magic wand key is W.
Double click on the magic wand tool to bring the options palette to the front.
The tolerance setting controls the range of color that will be selected and has a range from 0 to 255. To select a small range of colors enter a low number, for a wider range of color, select a high number.
The Use all Layers option allows you to select based on the data from all visible layers .