'Return the interpolation method the image uses when resizing.
One of \'nearest\', \'bilinear\', \'bicubic\', \'spline16\', \'spline36\',
\'hanning\', \'hamming\', \'hermite\', \'kaiser\', \'quadric\', \'catrom\',
\'gaussian\', \'bessel\', \'mitchell\', \'sinc\', \'lanczos\', or \'none\'.'

def get_interpolation(self):

    return self._interpolation
