code: public BufferedImage drawTile(GriddedTile griddedTile, Double[] values,
  			int tileWidth, int tileHeight) {
  
  		BufferedImage image = createImage(tileWidth, tileHeight);
  		WritableRaster raster = image.getRaster();
  		for (int x = 0; x < tileWidth; x++) {
  			for (int y = 0; y < tileHeight; y++) {
  				Double value = values[(y * tileWidth) + x];
  				short pixelValue = getPixelValue(griddedTile, value);
  				setPixelValue(raster, x, y, pixelValue);
  			}
  		}
  
  		return image;
  	}
docs: Draw a coverage data image tile from the flat array of coverage data
  values of length tileWidth * tileHeight where each coverage data value is
  at: (y * tileWidth) + x
  
  @param griddedTile
  gridded tile
  @param values
  coverage data values of length tileWidth * tileHeight
  @param tileWidth
  tile width
  @param tileHeight
  tile height
  @return coverage data image tile