This task performs a union or intersection of multiple ROI geometries into a single output ROI, Note that this task only works with geometry and will ignore ROIs that contain pixels or thresholds in their definitions.
            Example
            
            e = ENVI()
             
            
            File = Filepath('qb_boulder_roi.xml', Subdir=['data'], $
              Root_Dir=e.Root_Dir)
            Regions = e.OpenROI(File)
             
            
            Task = ENVITask('MergeROI')
             
            
            Task.INPUT_ROIS = Regions
            Task.OPERATION = 'Union'
            Task.ROI_COLOR = [200,0,0]
            Task.ROI_NAME = 'Union Example'
             
            
            Task.Execute
             
            
            e.Data.Add, Task.OUTPUT_ROI
             
            
            RasterFile = Filepath('qb_boulder_msi', Subdir=['data'], $
              Root_Dir=e.Root_Dir)
            View = e.GetView()
            BaseRaster = e.OpenRaster(RasterFile)
            Layer = View.CreateLayer(BaseRaster)
            roiLayer = Layer.AddRoi(Task.OUTPUT_ROI)
            Syntax
            Result = ENVITask('MergeROI')
            Input parameters (Set, Get): INPUT_ROIS, OPERATION, OUTPUT_ROI_URI, ROI_COLOR, ROI_NAME
            Output parameters (Get only): OUTPUT_ROI
            Parameters marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Parameters marked as "Get" are those whose values you can retrieve but not set.
            Input Parameters
            INPUT_ROIS (required)
            Specify the ROIs to merge.
            OPERATION (required)
            Specify which method used to merge the ROIs:
             
            The default value is Union.
            OUTPUT_ROI_URI (optional)
            Specify a string with the fully qualified path and filename for OUTPUT_ROI.
            ROI_COLOR (optional)
            Specify the RGB triplet values for the output ROI color.
            ROI_NAME (optional)
            Specify the name of the output ROI.
            Output Parameters
            OUTPUT_ROI
            This is a reference to the output ROI.
            Methods
            Execute             
            Parameter             
            ParameterNames
            
            Properties
            DESCRIPTION             
            DISPLAY_NAME
            
             NAME
            
             REVISION
            
             TAGS
            
            Version History
            
            See Also
            ENVITask, ENVITask::Parameter