code: public void setTransform( PixelTransform<Point2D_F32> undistToDist ) {
  		if( undistToDist != null ) {
  			InterpolatePixelS<T> interpolate = FactoryInterpolation.bilinearPixelS(imageType, BorderType.EXTENDED);
  			integralImage = new GImageGrayDistorted<>(undistToDist, interpolate);
  		} else {
  			integralImage = FactoryGImageGray.create(imageType);
  		}
  	}
docs: Used to specify a transform that is applied to pixel coordinates to bring them back into original input
  image coordinates.  For example if the input image has lens distortion but the edge were found
  in undistorted coordinates this code needs to know how to go from undistorted back into distorted
  image coordinates in order to read the pixel's value.
  
  @param undistToDist Pixel transformation from undistorted pixels into the actual distorted input image..