Photoshop Lasso Tool: Freeform Selection

The Lasso tool and the Polygonal Lasso tool let you draw both straight-edged and freehand segments of a selection border. With the Magnetic Lasso tool , the border snaps to the edges of defined areas in the image. The Magnetic Lasso tool is especially useful for quickly selecting objects with complex edges set against high-contrast backgrounds.

Tip: While you are using Lasso tool you can hold-down Alt(Option) key to draw straight-edged. By press and hold-down Alt(option) and then release mouse button. Now you can click to draw straight selection edges as long as you hold-down Alt(option) key.
To go back to draw free hand, just hold-down mouse button and release Alt(option) key. To close selection just release mouse button and Alt(Option) key.

Lasso Tool Option Short Cuts

If you already have selection in your picture you can use following key to perform Add, Subtract or Intersect. Press and hold the key before making selection. See Lasso tool option below for more detail for each operation..

• Shift: To add area to current selection.
• Alt: To remove area form current selection.
• Alt+Shift: To select only overlap(intersected) area of your current selection with new selection area.

Note: You may notice that when you hold down key your cross-hair cursor will change, form default , depend on each operation. Add , Subtract , Intersect . And also selection mode button in tool option bar will temporary switch to each mode depend on key pressing.

Magnetic Lasso Short-Cuts:

Following short-cuts are available for use with Magnetic Lasso tool only

• Cap Lock: To change the lasso cursor to indicate the lasso width. Change the cursor while the tool is selected but not in use.
• [ or ] :Press ] while creating a selection to increase the Magnetic Lasso edge width by 1 pixel. Press [ to decrease the width by 1 pixel.

Lasso Tool Options

Selection Mode (A): You can use the lasso tools to add to or subtract from existing pixel selections.

Note: Before manually adding to or subtracting from a selection, set the feather(b) and anti-aliased(c) values in the options bar to the same settings used for the original selection.

• Normal: Create New Selection. Your Current selection will be replace.
• Add: Add new selection area to current selection.
  
  
  
• Subtract: Remove new selection area to current selection.
  
  
  
• Intersected: Result in overlap area of your current selection and your new selection area.
  
  
  

Feather (B): 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. (See Also Using Photoshop Selection Feather)

Anti-Aliased(C): Smooth 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. Anti-aliasing is useful when cutting, copying, and pasting selections to create composite images. Turning off this option produces a hard-edged transition between pixels--and therefore the appearance of jagged edges.

Magnetic Lasso tool option (D): This group of options available for Magnetic Lasso tool only

• Width: To specify a detection width, enter a pixel value for Width. The Magnetic Lasso tool detects edges only within the specified distance from the pointer.
• Edge Contrast: To specify the lasso's sensitivity to edges in the image, enter a value between 1% and 100% A higher value detects only edges that contrast sharply with their surroundings; a lower value detects lower-contrast edges.
• Frequency: To specify the rate at which the lasso sets fastening points, enter a value between 0 and 100. A higher value anchors the selection border in place more quickly.
• Pen Pressure: If you are working with a stylus tablet, select or deselected the Stylus Pressure option. When the option is selected, an increase in stylus pressure will cause the edge width to decrease.

Tip: On an image with well-defined edges, try a higher width and higher edge contrast, and trace the border roughly. On an image with softer edges, try a lower width and lower edge contrast, and trace the border more precisely.

To use the Lasso tool:

Select the Lasso tool , and select options. (See Lasso Tool Option above.) Drag to draw a freehand selection border.

• To draw a straight-edged selection border: While making selection hold down Alt (Windows) or Option (Mac OS), and click where segments should begin and end. You can switch between drawing freehand and straight-edged segments.
  

  Note: If you have selection in your image, you have to press Alt(Option) key after you make selection or de-select it first. Otherwise you will perform Subtract selection (your cursor will change to )

• To erase recently drawn segments: Hold down the Delete key (keep pressing mouse button or Alt(Option) key) until you've erased the fastening points for the desired segment.
• To close the selection border: Release the mouse without holding down Alt (Windows) or Option (Mac OS).

Tip: If you already have selection in your image you can hold-down Shift, Alt(option) or Shift+Alt(option) to add, subtract or intersect you new selection with current selection. (See Lasso Short-cuts above for more detail)

To use the Polygonal Lasso tool:

Select the Polygonal Lasso tool , and select options. (See Lasso Tool Option above.) Click in the image to set the starting point.

• To draw a straight segment: Position the pointer where you want the first straight segment to end, and click. Continue clicking to set endpoints for subsequent segments.
• To draw a freehand segment: Hold down Alt (Windows) or Option (Mac OS), and drag. When finished, release Alt(Option) and the mouse button.
  

  Note: If you have selection in your image, you have to press Alt(Option) key after you make selection or de-select it first. Otherwise you will perform Subtract selection (your cursor will change to )

• To erase recently drawn straight segments: Press the Delete key.
• To Close the selection border: Position the Polygonal Lasso tool pointer over the starting point (a closed circle appears next to the pointer ), and click.If the pointer is not over the starting point, double-click the Polygonal Lasso tool pointer, or Ctrl-click (Windows) or Command-click (Mac OS).

Tip: If you already have selection in your image you can hold-down Shift, Alt(option) or Shift+Alt(option) to add, subtract or intersect you new selection with current selection. (See Lasso Short-cuts above for more detail

To use the Magnetic Lasso tool

1. Select the Magnetic Lasso tool , and select options. (See Lasso Tool Option above.)
2. Click in the image to set the first fastening point. Fastening points anchor the selection border in place.
3. To draw a freehand segment, move the pointer along the edge you want to trace. (You can also drag with the mouse button depressed.)
   The most recent segment of the selection border remains active. As you move the pointer, the active segment snaps to the strongest edge in the image, based on the detection Width set in the options bar. Periodically, the Magnetic Lasso tool adds fastening points to the selection border to anchor previous segments.
4. If the border doesn't snap to the desired edge, click once to add a fastening point manually. Continue to trace the edge, and add fastening points as needed.
5. To switch temporarily to the other lasso tools, do one of the following:
   • To activate the Lasso tool, hold down Alt (Windows) or Option (Mac OS), and drag with the mouse button depressed.
   • To activate the Polygonal Lasso tool, hold down Alt (Windows) or Option (Mac OS), and click.
6. To erase recently drawn segments and fastening points, press the Delete key until you've erased the fastening points for the desired segment.
7. Close the selection border:
   • To close the border with a freehand Magnetic segment, double-click, or press Enter or Return.
   • To close the border with a straight segment, hold down Alt (Windows) or Option (Mac OS), and double-click.
   • To close the border, drag back over the starting point and click.

Tip: To change the lasso cursor to indicate the lasso width, press the Caps Lock key on the keyboard. Change the cursor while the tool is selected but not in use.

Press ] while creating a selection to increase the Magnetic Lasso edge width by 1 pixel. Press [ to decrease the width by 1 pixel.

Related Article:

• Define Selection Edge
• Photoshop CS3 Toolbox: Quick Reference
• Photoshop Quick Selection Tool
• Photoshop Marquee Tool
• Photoshop Magic-Wand Tool
• Using Photoshop Tool Preset
• Using Photoshop Selection Feather

Post Footer automatically generated by Add Post Footer Plugin for wordpress.

	Share This	Bookmarks this Page

This entry was posted on Thursday, April 5th, 2007 at 4:01 am. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.