code: public byte[] drawTileData(int[][] unsignedPixelValues) {
  		BufferedImage image = drawTile(unsignedPixelValues);
  		byte[] bytes = getImageBytes(image);
  		return bytes;
  	}
docs: Draw a coverage data image tile and format as PNG bytes from the double
  array of unsigned 16 bit integer pixel values formatted as
  int[row][width]
  
  @param unsignedPixelValues
  unsigned 16 bit integer pixel values as [row][width]
  @return coverage data image tile bytes