I am working with Erdas Imagine's Signature Editor to perform maximum likelihood classification.  I need to use the same training set created in Erdas for other classification using R.  Is there a way to extract the raster band pixel values under the .aoi polygons and export that information to a .txt or .csv?  I am looking for the same functionality as the ArcGIS [Sample][1] tool where the individual raster band pixel values are extracted underneath points and written to a table (e.g. Figure 2).  Alternatively, is it possible to export the signature editor table (i.e. including R,G,B,NIR bands and the class label) to a .csv? 

For example, I need the functionality of the signature editor

Figure1
![enter image description here][2]

Yet I need to convert these values to a format that I can read into R.  Note that I need all four bands of the input image along with a class ID (i.e. grid code).  This table was generated in ArcGIS.

Figure 2
![enter image description here][3]


  [1]: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009z0000002v000000.htm
  [2]: https://i.sstatic.net/1VeY8.png
  [3]: https://i.sstatic.net/wTtek.png