code: function(rectangle) {
          return $.Rect.fromSummits(
              this.pointFromPixel(rectangle.getTopLeft(), true),
              this.pointFromPixel(rectangle.getTopRight(), true),
              this.pointFromPixel(rectangle.getBottomLeft(), true)
          );
      }
docs: Convert a rectangle in pixel coordinates relative to the viewer element
  to viewport coordinates.
  @param {OpenSeadragon.Rect} rectangle the rectangle to convert
  @returns {OpenSeadragon.Rect} the converted rectangle