def __call__(self, img):
        """
        Args:
            img (numpy.ndarray): Image of size (H, W, C) to be normalized.

        Returns:
            Tensor: Normalized image.
        """
        if not(_is_numpy_image(img)):
            raise TypeError('img should be ndarray. Got {}'.format(type(img)))
        # TODO: make efficient
        print(img.shape)
        for i in range(3):
            img[:,:,i] = (img[:,:,i] - self.mean[i]) / self.std[i]
        return img

        Args:
            img (numpy.ndarray): Image of size (H, W, C) to be normalized.

        Returns:
            Tensor: Normalized image.
        
dataloaders/transforms.py