Ulead VIDEOGRAPHICS LAB Manual page 38

34 VIDEOGRAPHICS LAB USER GUIDE
When you create a selection, it starts from where you first click your
mouse. This is fine in most cases, but sometimes you may want it to start
from the center, particularly if you are creating circular or square shapes.
To do this, first click the Draw From Center button on the Attribute
toolbar and then drag your mouse over the image starting from where you
want the center of the selection to be.
Creating a regular selection area
Selecting irregularly shaped areas
The Lasso tool allows you to select an area by drawing a freehand shape.
This is especially useful for selecting difficult areas, such as a person's
head or objects with a number of different angles. It operates in two ways:
Dragging your mouse allows you to draw precise curved segments;
clicking your mouse allows you to define straight line segments. By
combining both drawing techniques, you can quickly outline selection
areas that contain both irregular and straight segments. When you have
finished outlining the selection area, double-click to release the Lasso and
Video Paint automatically selects all image data within the bounds of the
drawn selection area.
By checking the AutoSnap option on the Attribute toolbar, and then
entering a value into the Sensitivity entry box (up to 10), Video Paint can
help you quickly trace around irregularly shaped objects. The Sensitivity
attribute works by specifying the range of contrast values that are used to
define an object's edge and AutoSnap pulls the selection area to that edge
as you draw. This works best when you are tracing a bright foreground