def test_user_inputs_raises(user_input_params):
# GIVEN a set of inputs of the wrong data type or shape
input_data, exception = user_input_params
# WHEN an attempt is made to decode it
# THEN it raises a particular exception
with pytest.raises(exception):
ljpeg.decode(input_data)
def test_decode_unsupported_marker_raises(example_numpy_lossy_photo):
# GIVEN a lossy jpg (which isn't supported)
input_file = example_numpy_lossy_photo
# WHEN there's an attempt to decode it
# THEN it raises an exception
with pytest.raises(NotImplementedError):
ljpeg.decode(input_file)
def test_decode_tqi_value_raises(example_numpy_lossless_photo_w_bad_tqi_value):
# GIVEN a lossless jpg with a bad Hi value
input_file = example_numpy_lossless_photo_w_bad_tqi_value
expected = 'Tqi should be zero'
# WHEN an attempt is made to decode it
# THEN it raises a particular exception with particular text
with pytest.raises(ValueError) as e:
ljpeg.decode(input_file)
err_msg = e.value.args[0]
assert err_msg == expected
def test_decode_vi_value_raises(example_numpy_lossless_photo_w_bad_vi_value):
# GIVEN a lossless jpg with a bad Hi value
input_file = example_numpy_lossless_photo_w_bad_vi_value
expected = 'Pixels are an unsupported shape, Vi'
# WHEN attempt is made to decode it
# THEN it raises a particular exception with particular text
with pytest.raises(NotImplementedError) as e:
ljpeg.decode(input_file)
err_msg = e.value.args[0]
assert err_msg == expected
def test_decode_huffman_value_raises(
example_numpy_lossless_photo_w_bad_huffman_value):
# GIVEN a lossless jpg with bad huffman values
input_file = example_numpy_lossless_photo_w_bad_huffman_value
expected = 'No matching Huffman code was found for a lossless tile jpeg lkj'
# WHEN attempt is made to decode it
# THEN it raises a particular exception with particular text
with pytest.raises(ValueError) as e:
ljpeg.decode(input_file)
err_msg = e.value.args[0]
assert err_msg == expected
def test_decode_success(good_example_numpy_lossless_photo_w_decoded):
# GIVEN a good lossless jpg that's been unpacked into a 1D numpy array of type intc
# and what should result from decoding the jpg
input_file, expected_array = good_example_numpy_lossless_photo_w_decoded
# WHEN the supplied file is decoded
test_file = ljpeg.decode(input_file)
# THEN the test_file should math the expected_array
assert np.array_equal(expected_array, test_file)
def test_encode_success(rgb_numpy_photo):
# GIVEN a decoded photo in a 3D numpy array with a precision of 8
# WHEN encode is run twice to ensure that everyting's reinitialized properly
# and then decoded
ljpeg.encode(rgb_numpy_photo, 8, 5)
actual = np.asarray(ljpeg.encode(rgb_numpy_photo, 8, 5)).astype(np.intc)
actual = ljpeg.decode(actual)
# THEN the decoded image is the same as the input data
assert np.array_equal(rgb_numpy_photo, actual)