code: public Double getValue(GriddedTile griddedTile, float pixelValue) {
  
  		Double value = null;
  		if (!isDataNull(pixelValue)) {
  			value = pixelValueToValue(griddedTile, new Double(pixelValue));
  		}
  
  		return value;
  	}
docs: Get the coverage data value for the pixel value
  
  @param griddedTile
  gridded tile
  @param pixelValue
  pixel value
  @return coverage data value