The ROI is the green box that appears on the screen
when you select certain tools.
Some of
the tools work on the entire image and others allow you to define
where you want them to work. The ROI box allows you to tell
that
tool where to work. The ROI box can be placed anywhere on the
Viewer window and can be resized and rotated as needed.
When the ROI box
is selected it will
turn red and 10 smaller boxes will be placed around the ROI so you can
resize and rotate it.
If you hold CTRL
down when resizing the
ROI will maintain a perfectly square shape.
If you hold Shift while rotating it will rotate in 15 degree increments.
If you
right-click inside the ROI it
will display the ROIEntity edit page. Selecting the Entity
tab allows you to adjust the colors, thickness, handle size and
visibility of the ROI box. You can also select a Coordinate
System - this controls how the ROI understands where it is on the
screen.
Selecting
the Rectangle tab allows you to enter specific values for the ROI
rectangle used, including center X, Y, width, height, angle and aspect
of width/height. After entering your values, click Apply then
Close. Note the angle is in radians. You can uses the ellipses edit buton and convert
eg if you want 17 deg type 17*PI/180 and hit calculate
The ROI will be adjusted according to the selections.