def _rndLetterTransform(self, image):
        """Randomly morph a single character."""
        w, h = image.size

        dx = w * random.uniform(0.2, 0.7)
        dy = h * random.uniform(0.2, 0.7)

        x1, y1 = self.__class__._rndPointDisposition(dx, dy)
        x2, y2 = self.__class__._rndPointDisposition(dx, dy)

        w += abs(x1) + abs(x2)
        h += abs(x1) + abs(x2)

        quad = self.__class__._quadPoints((w, h), (x1, y1), (x2, y2))

        return image.transform(image.size, Image.QUAD,
                               data=quad, resample=self.resample)
Randomly morph a single character.