imroi Class
(Not recommended) Region-of-interest (ROI) abstract base class
The imroi abstract class and its inherited classes are not
            recommended. Use new ROI objects instead. For more information, see Version History.
Description
The imroi class is an abstract base class that specifies the
                Image Processing Toolbox™ interface for working with regions of interest (ROIs). You can use classes
            that inherit from the imroi interface to create interactive ROIs over
            an image.
The imroi class is a handle class.
Creation
The imroi class is abstract, and creating an instance of the
                imroi class is not allowed. To learn how to create an ROI object
            from a concrete subclass of imroi, see imellipse, imfreehand, imline, impoint, impoly, or imrect.