'Augmenter body'

def __call__(self, src):

    alpha = (1.0 + random.uniform((- self.saturation), self.saturation))
    gray = (src * self.coef)
    gray = nd.sum(gray, axis=2, keepdims=True)
    gray *= (1.0 - alpha)
    src *= alpha
    src += gray
    return [src]
