The HDF_DFR8_READREF procedure sets the reference number of the image to be read from an HDF file by the next call to HDF_DFR8_GETIMAGE.
            Syntax
            HDF_DFR8_READREF, Filename, Reference_number
            Arguments
            Filename
            A scalar string containing the name of the file to be read.
            Reference_number
            A reference number for an 8-bit raster image.
            Keywords
            None 
            Version History