def test_offset_invertability():
picture = {
"Y": new_array(8, 16, 123),
"C1": new_array(4, 8, 456),
"C2": new_array(4, 8, 789),
}
for row in picture["Y"]:
for i in range(len(row)):
row[i] = 123
for row in picture["C1"]:
for i in range(len(row)):
row[i] = 456
for row in picture["C2"]:
for i in range(len(row)):
row[i] = 789
state = {
"luma_depth": 8,
"color_diff_depth": 10,
}
remove_offset_picture(state, picture)
assert picture["Y"][0][0] == 123 - 128
assert picture["C1"][0][0] == 456 - 512
assert picture["C2"][0][0] == 789 - 512
offset_picture(state, picture)
assert picture["Y"][0][0] == 123
assert picture["C1"][0][0] == 456
assert picture["C2"][0][0] == 789
def vh_analysis(state, data):
"""
Interleaved vertical and horizontal analysis, inverse of vh_synthesis (15.4.3).
Returns a tuple (LL_data, HL_data, LH_data, HH_data)
"""
# Bit shift, if required
shift = filter_bit_shift(state)
if shift > 0:
for y in range(0, height(data)):
for x in range(0, width(data)):
data[y][x] = data[y][x] << shift
# Analysis
for y in range(0, height(data)):
oned_analysis(row(data, y), state["wavelet_index_ho"])
for x in range(0, width(data)):
oned_analysis(column(data, x), state["wavelet_index"])
# De-interleave the transform data
LL_data = new_array(height(data) // 2, width(data) // 2)
HL_data = new_array(height(data) // 2, width(data) // 2)
LH_data = new_array(height(data) // 2, width(data) // 2)
HH_data = new_array(height(data) // 2, width(data) // 2)
for y in range(0, (height(data) // 2)):
for x in range(0, (width(data) // 2)):
LL_data[y][x] = data[2 * y][2 * x]
HL_data[y][x] = data[2 * y][2 * x + 1]
LH_data[y][x] = data[2 * y + 1][2 * x]
HH_data[y][x] = data[2 * y + 1][2 * x + 1]
return (LL_data, HL_data, LH_data, HH_data)
def h_analysis(state, data):
"""
Horizontal-only analysis, inverse of h_synthesis (15.4.2).
Returns a tuple (L_data, H_data)
"""
# Bit shift, if required
shift = filter_bit_shift(state)
if shift > 0:
for y in range(0, height(data)):
for x in range(0, width(data)):
data[y][x] = data[y][x] << shift
# Analysis
for y in range(0, height(data)):
oned_analysis(row(data, y), state["wavelet_index_ho"])
# De-interleave the transform data
L_data = new_array(height(data), width(data) // 2)
H_data = new_array(height(data), width(data) // 2)
for y in range(0, (height(data))):
for x in range(0, (width(data) // 2)):
L_data[y][x] = data[y][2 * x]
H_data[y][x] = data[y][(2 * x) + 1]
return (L_data, H_data)
def two_d_array():
"""A 2D array of numbers for test purposes."""
a = new_array(16, 32)
for y in range(height(a)):
for x in range(width(a)):
a[y][x] = (y * 100) + x
return a
def test_2d(self):
assert new_array(4, 3) == [
[None, None, None],
[None, None, None],
[None, None, None],
[None, None, None],
]
def vh_synthesis(state, LL_data, HL_data, LH_data, HH_data):
"""(15.4.3) Interleaved vertical and horizontal synthesis."""
synth = new_array(2 * height(LL_data), 2 * width(LL_data))
# Interleave transform data (as expected by synthesis routine)
for y in range(height(synth) // 2):
for x in range(width(synth) // 2):
synth[2 * y][2 * x] = LL_data[y][x]
synth[2 * y][2 * x + 1] = HL_data[y][x]
synth[2 * y + 1][2 * x] = LH_data[y][x]
synth[2 * y + 1][2 * x + 1] = HH_data[y][x]
# Synthesis
for x in range(width(synth)):
oned_synthesis(column(synth, x), state["wavelet_index"])
for y in range(height(synth)):
oned_synthesis(row(synth, y), state["wavelet_index_ho"])
# Bit shift, if required
shift = filter_bit_shift(state)
if shift > 0:
for y in range(height(synth)):
for x in range(width(synth)):
synth[y][x] = (synth[y][x] + (1 << (shift - 1))) >> shift
return synth
def h_synthesis(state, L_data, H_data):
"""(15.4.2) Horizontal-only synthesis."""
synth = new_array(height(L_data), 2 * width(L_data))
# Interleave transform data (as expected by synthesis routine)
for y in range(height(synth)):
for x in range(width(synth) // 2):
synth[y][2 * x] = L_data[y][x]
synth[y][(2 * x) + 1] = H_data[y][x]
# Synthesis
for y in range(height(synth)):
oned_synthesis(row(synth, y), state["wavelet_index_ho"])
# Bit shift, if required
shift = filter_bit_shift(state)
if shift > 0:
for y in range(height(synth)):
for x in range(width(synth)):
synth[y][x] = (synth[y][x] + (1 << (shift - 1))) >> shift
return synth
def num_array():
a = new_array(3, 5)
for x in range(width(a)):
for y in range(height(a)):
a[y][x] = x + (y * 10)
return a
def test_height():
assert height(new_array(0, 0)) == 0
assert height(new_array(20, 10)) == 20
def test_width():
assert width(new_array(0, 0)) == 0
assert width(new_array(20, 10)) == 10
def test_2d_singleton(self):
assert new_array(1, 1) == [[None]]
def test_2d_empty(self):
assert new_array(0, 0) == []
def test_1d(self):
assert new_array(0) == []
assert new_array(3) == [None, None, None]
