7. The Menus / 7.6 The Tool Menu
Form Lasso can be called by double-clicking Rectangle Lasso or Circle Lasso (see chapter 6.2.20).
It is used to create a new lasso or to modify an existing one. Mode: is the working mode: Replace replaces the current lasso, Add adds the new lasso to the current one and Remove subtracts it.
Shape: is the shape of the new lasso.
Relative and Absolute define whether Position and Size are relative to the size of the image or are given in a unit like mm or pixel.
Frame Width controls, how strong the edge of the lasso will be softened.