code: public static Coordinate coordinateFromColRow( int col, int row, GridGeometry2D gridGeometry ) {
          try {
              GridCoordinates2D pos = new GridCoordinates2D(col, row);
              DirectPosition gridToWorld = gridGeometry.gridToWorld(pos);
              double[] coord = gridToWorld.getCoordinate();
              return new Coordinate(coord[0], coord[1]);
          } catch (InvalidGridGeometryException e) {
              e.printStackTrace();
          } catch (TransformException e) {
              e.printStackTrace();
          }
          return null;
      }
docs: Utility method to get the coordinate of a col and row from a {@link GridGeometry2D}.
  
  @param col the col to transform.
  @param row the row to transform.
  @param gridGeometry the gridgeometry to use.
  @return the coordinate or <code>null</code> if something went wrong.