Specifies the types of non-rectangular Region of Interest (ROI).

Values:

IG_ROI_IS_RECTANGLE	The ROI is a rectangle.
IG_ROI_IS_ELLIPSE	The ROI is an ellipse.
IG_ROI_IS_POLYGON	The ROI is a polygon.

Remarks:

These modes are used with IG_IP_NR_ROI_to_HIGEAR_mask and describe what kind of non-rectangular ROI is passed in.