Marquee & Lasso Selection Tools

General note: When making a 'selection' the boundaries of the selected area become visible by the appearance of 'marching ants' (yes, that's what they're called - a throw back so far as I know to the rows of ants marching towards their goal in cartoon films such as Tom & Jerry).

Marching Ants (selection boundaries) can be deselected by Selection > De-Select (or quick-key Ctrl + D)

Marching Ants can also be hidden by View > Show > Selection Edges (this may vary in earlier versions) the quick-key is Ctrl + H, simple and quick to do and it's a 'toggle' so repeating the key stroke will show the edges once again.

Rectangular Marquee
The selection is made by the (left) click-drag method. To make a proportionally square rectangle, hold down the Shift key as you drag. Release the mouse (or graphics pen) before you release Shift.

Elliptical Marquee
The selection is made by the (left) click-drag method.
The proportionality of the ellipse or to make it a circle can be controlled:
Shift / -drag = Circle from an edge (Release the mouse (or graphics pen) before you release Shift.)
Or
Shift + Alt / click-drag = Circle from centre (Release the mouse (or graphics pen) before you release Shift.)

Lasso: The basic free-hand Lasso Tool can be used to draw around an area. To complete the circuit, release the mouse (or graphics pen) when you return to the starting position.

Polygon Lasso: This tool is excellent for selecting the outline of straight-line (but not necessarily right-angular) geometric shapes, rooflines, doors, windows, etc. The route of Poly Lasso is advanced by a series of clicks, making 'node points'. Click to make the first node point, then move to next node point, click move to next point and so on. When the tool is very close to the start position, a small Poly Lasso icon appears, release the mouse (or graphics pen) and the route will be completed. If you're near the end and can't quite see the start point, using the Enter key will complete the route.

Undoing the Poly Lasso
The polygon lasso can be undone step-by-step (node-to-node) by using the 'Delete' key.

Escaping from the 'Polygon Mesh'
Frequently people get into an awful mess when they discover that they can't find the end or simply wish to quit (looks like a bad case of knitting!) with diagonal lines all over the place. To escape, simply press the Esc (Escape) key.

Click on 'Selection Tools continued' to proceed