def test_run_length(self):
matrix = np.array([[99, -59, 0, 7, 0, 0, 0,
0], [0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0],
[12, -2, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0]])
rl = codec.run_length_coding(transform.zigzag(matrix))
expected = [{
'zeros': 0,
'value': 99,
'bits': 7
}, {
'zeros': 1,
'value': -59,
'bits': 6
}, {
'zeros': 6,
'value': 7,
'bits': 3
}, {
'zeros': 4,
'value': 12,
'bits': 4
}, {
'zeros': 1,
'value': -2,
'bits': 2
}, {
'zeros': 0,
'value': 0,
'bits': 0
}]
self.assertEqual([codec.RunLength.from_dict(e) for e in expected], rl)
def test_run_length_trivial(self):
matrix = np.array([[1, 2], [3, 4]])
rl = codec.run_length_coding(transform.zigzag(matrix)[1:])
self.assertEqual(rl, [
codec.RunLength(3, 0),
codec.RunLength(2, 0),
codec.RunLength(4, 0)
])
def test_zigzag(self):
matrix = np.array([
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
])
d = trans.zigzag(matrix)
self.assertTrue(np.array_equiv([
1, 4, 2, 3, 5, 7, 8, 6, 9
], d))
def test_pull_subbands(self):
expected = [
np.array(range(4)).reshape((2, 2)),
np.array(range(4, 8)).reshape((2, 2)),
np.array(range(8, 12)).reshape((2, 2)),
np.array(range(12, 16)).reshape((2, 2)),
np.array(range(16, 32)).reshape((4, 4)),
np.array(range(32, 48)).reshape((4, 4)),
np.array(range(48, 64)).reshape((4, 4))
]
data = np.array(utils.flatten([transform.zigzag(m) for m in expected]))
shapes = [(2, 2), (4, 4)]
out = codec.wavelet_decode_pull_subbands(data, shapes)
self.assertEqual(len(expected), len(out))
z = zip(expected, out)
for e in z:
self.assertTrue(np.array_equal(e[0], e[1]))
def collapse_subbands(k, v):
out = [transform.zigzag(l) for l in v]
out = utils.flatten(out)
return out
def test_zero_block_reconstruct(self):
matrix = np.array([[0, 0, 11, 0], [0, 0, 0, 0]])
lin = transform.zigzag(matrix)
out = codec.run_length_coding(lin)
invert = codec.decode_run_length(out, 8)
self.assertEqual(lin, invert)
def test_zero_block_rle(self):
matrix = np.array([[0, 0, 11, 0], [0, 0, 0, 0]])
lin = transform.zigzag(matrix)
out = codec.run_length_coding(lin)
self.assertEqual(out, [codec.RunLength(11, 3), codec.RunLength(0, 0)])
def test_zigzag_inverse(self):
matrix = np.random.randint(0, 256, (17, 19))
ziggy = trans.zigzag(matrix)
imat = trans.izigzag(ziggy, matrix.shape)
self.assertTrue(np.array_equiv(matrix, imat))