Lasso & Wand Selection Tools

Lasso & Wand Selection 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.

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.

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. These options are explained in my magnetic lasso tutorial, which is part of the assignment for this lesson.

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 lasson 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.

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 (we'll be learning more about layers in the next lesson).

When contiguous is checked, the selection only includes adjacent pixels of the same color range. If you wanted to select islands of color all at once, you would deselect the contiguous option.

As with the other selection tools, you can use Shift to add to the selection, and Alt/Option to subtract from the selection.