def test_wavelet_decomposition3d_and_reconstruction3d():
# Test 3D wavelet decomposition and reconstruction and verify that
# they perform as expected
x = np.random.rand(16, 16, 16)
mode = 'sym'
wbasis = pywt.Wavelet('db5')
nscales = 1
wavelet_coeffs = wavelet_decomposition3d(x, wbasis, mode, nscales)
aaa = wavelet_coeffs[0]
reference = pywt.dwtn(x, wbasis, mode)
aaa_reference = reference['aaa']
assert all_almost_equal(aaa, aaa_reference)
reconstruction = wavelet_reconstruction3d(wavelet_coeffs, wbasis, mode,
nscales)
reconstruction_reference = pywt.idwtn(reference, wbasis, mode)
assert all_almost_equal(reconstruction, reconstruction_reference)
assert all_almost_equal(reconstruction, x)
assert all_almost_equal(reconstruction_reference, x)
wbasis = pywt.Wavelet('db1')
nscales = 3
wavelet_coeffs = wavelet_decomposition3d(x, wbasis, mode, nscales)
shape_true = (nscales + 1, )
assert all_equal(np.shape(wavelet_coeffs), shape_true)
reconstruction = wavelet_reconstruction3d(wavelet_coeffs, wbasis, mode,
nscales)
assert all_almost_equal(reconstruction, x)
def test_wavelet_decomposition3d_and_reconstruction3d():
# Test 3D wavelet decomposition and reconstruction and verify that
# they perform as expected
x = np.random.rand(16, 16, 16)
mode = 'sym'
wbasis = pywt.Wavelet('db5')
nscales = 1
wavelet_coeffs = wavelet_decomposition3d(x, wbasis, mode, nscales)
aaa = wavelet_coeffs[0]
reference = pywt.dwtn(x, wbasis, mode)
aaa_reference = reference['aaa']
assert all_almost_equal(aaa, aaa_reference)
reconstruction = wavelet_reconstruction3d(wavelet_coeffs, wbasis, mode,
nscales)
reconstruction_reference = pywt.idwtn(reference, wbasis, mode)
assert all_almost_equal(reconstruction, reconstruction_reference)
assert all_almost_equal(reconstruction, x)
assert all_almost_equal(reconstruction_reference, x)
wbasis = pywt.Wavelet('db1')
nscales = 3
wavelet_coeffs = wavelet_decomposition3d(x, wbasis, mode, nscales)
shape_true = (nscales + 1, )
assert all_equal(np.shape(wavelet_coeffs), shape_true)
reconstruction = wavelet_reconstruction3d(wavelet_coeffs, wbasis, mode,
nscales)
assert all_almost_equal(reconstruction, x)
def test_pywt_coeff_to_array_and_array_to_pywt_coeff():
# Verify that the helper function does indeed work as expected
wbasis = pywt.Wavelet('db1')
mode = 'zpd'
nscales = 2
n = 16
# 1D test
size_list = coeff_size_list((n,), nscales, wbasis, mode)
x = np.random.rand(n)
coeff_list = pywt.wavedec(x, wbasis, mode, nscales)
coeff_arr = pywt_coeff_to_array(coeff_list, size_list)
assert isinstance(coeff_arr, (np.ndarray))
length_of_array = np.prod(size_list[0])
length_of_array += sum(np.prod(shape) for shape in size_list[1:-1])
assert all_equal(len(coeff_arr), length_of_array)
coeff_list2 = array_to_pywt_coeff(coeff_arr, size_list)
assert all_equal(coeff_list, coeff_list2)
reconstruction = pywt.waverec(coeff_list2, wbasis, mode)
assert all_almost_equal(reconstruction, x)
# 2D test
size_list = coeff_size_list((n, n), nscales, wbasis, mode)
x = np.random.rand(n, n)
coeff_list = pywt.wavedec2(x, wbasis, mode, nscales)
coeff_arr = pywt_coeff_to_array(coeff_list, size_list)
assert isinstance(coeff_arr, (np.ndarray))
length_of_array = np.prod(size_list[0])
length_of_array += sum(3 * np.prod(shape) for shape in size_list[1:-1])
assert all_equal(len(coeff_arr), length_of_array)
coeff_list2 = array_to_pywt_coeff(coeff_arr, size_list)
assert all_equal(coeff_list, coeff_list2)
reconstruction = pywt.waverec2(coeff_list2, wbasis, mode)
assert all_almost_equal(reconstruction, x)
# 3D test
size_list = coeff_size_list((n, n, n), nscales, wbasis, mode)
x = np.random.rand(n, n, n)
coeff_dict = wavelet_decomposition3d(x, wbasis, mode, nscales)
coeff_arr = pywt_coeff_to_array(coeff_dict, size_list)
assert isinstance(coeff_arr, (np.ndarray))
length_of_array = np.prod(size_list[0])
length_of_array += sum(7 * np.prod(shape) for shape in size_list[1:-1])
assert len(coeff_arr) == length_of_array
coeff_dict2 = array_to_pywt_coeff(coeff_arr, size_list)
reconstruction = wavelet_reconstruction3d(coeff_dict2, wbasis, mode,
nscales)
assert all_equal(coeff_dict, coeff_dict)
assert all_almost_equal(reconstruction, x)
def test_pywt_coeff_to_array_and_array_to_pywt_coeff():
# Verify that the helper function does indeed work as expected
wbasis = pywt.Wavelet('db1')
mode = 'zpd'
nscales = 2
n = 16
# 1D test
size_list = coeff_size_list((n,), nscales, wbasis, mode)
x = np.random.rand(n)
coeff_list = pywt.wavedec(x, wbasis, mode, nscales)
coeff_arr = pywt_coeff_to_array(coeff_list, size_list)
assert isinstance(coeff_arr, (np.ndarray))
length_of_array = np.prod(size_list[0])
length_of_array += sum(np.prod(shape) for shape in size_list[1:-1])
assert all_equal(len(coeff_arr), length_of_array)
coeff_list2 = array_to_pywt_coeff(coeff_arr, size_list)
assert all_equal(coeff_list, coeff_list2)
reconstruction = pywt.waverec(coeff_list2, wbasis, mode)
assert all_almost_equal(reconstruction, x)
# 2D test
size_list = coeff_size_list((n, n), nscales, wbasis, mode)
x = np.random.rand(n, n)
coeff_list = pywt.wavedec2(x, wbasis, mode, nscales)
coeff_arr = pywt_coeff_to_array(coeff_list, size_list)
assert isinstance(coeff_arr, (np.ndarray))
length_of_array = np.prod(size_list[0])
length_of_array += sum(3 * np.prod(shape) for shape in size_list[1:-1])
assert all_equal(len(coeff_arr), length_of_array)
coeff_list2 = array_to_pywt_coeff(coeff_arr, size_list)
assert all_equal(coeff_list, coeff_list2)
reconstruction = pywt.waverec2(coeff_list2, wbasis, mode)
assert all_almost_equal(reconstruction, x)
# 3D test
size_list = coeff_size_list((n, n, n), nscales, wbasis, mode)
x = np.random.rand(n, n, n)
coeff_dict = wavelet_decomposition3d(x, wbasis, mode, nscales)
coeff_arr = pywt_coeff_to_array(coeff_dict, size_list)
assert isinstance(coeff_arr, (np.ndarray))
length_of_array = np.prod(size_list[0])
length_of_array += sum(7 * np.prod(shape) for shape in size_list[1:-1])
assert len(coeff_arr) == length_of_array
coeff_dict2 = array_to_pywt_coeff(coeff_arr, size_list)
reconstruction = wavelet_reconstruction3d(coeff_dict2, wbasis, mode,
nscales)
assert all_equal(coeff_dict, coeff_dict)
assert all_almost_equal(reconstruction, x)