code: def closing(input_rasterfilename, times):
          
          input_raster = RasterUtilClass.read_raster(input_rasterfilename)
          closing_raster = input_raster
          for i in range(times):
              closing_raster = RasterUtilClass.raster_dilation(closing_raster)
          for i in range(times):
              closing_raster = RasterUtilClass.raster_erosion(closing_raster)
          return closing_raster
docs: Do closing.
  
          Closing: Dilate firstly, then Erode.
  
          Args:
              input_rasterfilename: input original raster image filename.
              times: Erode and Dilate times.
  
          Returns:
              closing_raster: raster image after close.