This is a reference to an ROI object.
            Example
            
            e = ENVI()
             
            
            file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $
              SUBDIRECTORY = ['data'])
            raster = e.OpenRaster(file)
             
            
            roi1 = ENVIROI(NAME='Region 1', COLOR='Blue')
             
            
            Print, roi1
            IDL prints:
            ENVIROI <244676>
              COLOR = 0, 0, 255
              NAME = 'Region 1'
              N_DEFINITIONS = 0
            See More Examples.
            Syntax
            Result = ENVIROI([, Keywords=value])
            Methods
            AddGeometry
            
             AddPixels
            
            AddThreshold
            
            AddVectorRecords
            
            ClearGeometry
            
            ClearPixels
            
            ClearThresholds
            
            ClearVectorRecords
            
             Close
            
             Dehydrate
            
             GetExtent
            
            GrowRegion
            
             Hydrate
            
            PixelAddresses
            
             Pixelate
            
            PixelCount
            
             Revert
            
             Save
            
            Properties
            Properties can be set as keywords to functions during creation, or retrieved or changed using the "." notation after creation.
            COLOR
            Set this property to a string or RGB vector that specifies the color of the ROI. If this property is not set, then it will use a default color.
            The following table lists the single characters that you can use as the color modifier in either the COLOR property or the Format string argument. You must use the lower-case character.
            
                
                                 
                    
                        | Color Name | Character | 
                                  
                    
                        | Blue | b | 
                     
                        | Green | g | 
                     
                        | Red | r | 
                     
                        | Cyan | c | 
                     
                        | Magenta | m | 
                     
                        | Yellow | y | 
                     
                        | Black | k | 
                     
                        | White | w | 
                              
            When setting the COLOR property, you can also use any of the string values defined by the !COLOR system variable, as shown in the following image:
                              
            
             NAME
            Use this property to specify a named variable that contains a ROI name. If this property is not set, then it will use a default name that is currently not in use, starting with Region 1.
            More Examples
            This example shows how to get the properties of multiple ROI records within a single ROI file:
            
            e = ENVI()
             
            
            file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $
              SUBDIRECTORY = ['data'])
            raster = e.OpenRaster(file)
             
            
            ROIFile = FILEPATH('qb_boulder_roi.xml', $
              ROOT_DIR=e.ROOT_DIR, SUBDIRECTORY = ['data'])
            rois = e.OpenROI(ROIFile)
             
            
            For i=0, n_elements(rois)-1 do $
              Print, rois[i]
            IDL prints:
            ENVIROI <231489>
              COLOR                     = 240, 240,   0
              NAME                      = 'Disturbed Earth'
              N_DEFINITIONS             = 1
             
            ENVIROI <231490>
              COLOR                     = 255,   0,   0
              NAME                      = 'Bright Roof'
              N_DEFINITIONS             = 1
             
            ENVIROI <231491>
              COLOR                     = 29,  29, 255
              NAME                      = 'Water'
              N_DEFINITIONS             = 1
            Also see How do I process the pixels within a region of interest (ROI)?
            Version History
            
                                 
                                 
                                     
                        | ENVI 5.1 | Introduced | 
                     
                        | ENVI 5.3.1 | Added Dehydrate method | 
                    
                        | ENVI 5.4 | Added Hydrate method | 
                 
            
            See Also
            ENVI function, ENVI::OpenRaster, ENVIRasterLayer::AddROI, ENVI::OpenROI, VectorAttributeToROIs Task, VectorRecordsToSeparateROI Task, VectorRecordsToROI Task