code: public static ImageBuffer getRasterBuffer(ImageBuffer img, double fr, double fg, double fb)
      {
          return factoryGraphic.getRasterBuffer(img, fr, fg, fb);
      }
docs: Get raster buffer from data.
  
  @param img The image buffer (must not be <code>null</code>).
  @param fr The first red.
  @param fg The first green.
  @param fb The first blue.
  @return The rastered image.
  @throws LionEngineException If invalid arguments.