code: def to_grayscale(self):
          
          gray_data = cv2.cvtColor(self.data, cv2.COLOR_RGB2GRAY)
          return GrayscaleImage(gray_data, frame=self.frame)
docs: Converts the color image to grayscale using OpenCV.
  
          Returns
          -------
          :obj:`GrayscaleImage`
              Grayscale image corresponding to original color image.