def test_es_values():
    image = Image([[1., 2.], [2., 1.]])
    es_img = es(image)
    k = 1.0 / (2 * (2 ** 0.5))
    res = np.array([[[k, -k], [k, -k]], [[k, k], [-k, -k]]])
    assert_allclose(es_img.pixels, res)
dataset/ETHPy150Open menpo/menpo/menpo/feature/test/test_features.py/test_es_values/original