def test_parameters(self):
"""Test getting the parameters for a JPEG2K codestream."""
base = b'\xff\x4f\xff\x51' + b'\x00' * 38
# Signed
for ii in range(135, 143):
params = get_j2k_parameters(base + bytes([ii]))
assert ii - 127 == params['precision']
assert params['is_signed']
# Unsigned
for ii in range(7, 17):
params = get_j2k_parameters(base + bytes([ii]))
assert ii + 1 == params['precision']
assert not params['is_signed']
def test_short_bytestream(self):
"""Test result when no SIZ box present"""
assert {} == get_j2k_parameters(b'')
assert {} == get_j2k_parameters(b'\xff\x4f\xff\x51' + b'\x00' * 20)
def test_no_siz(self):
"""Test result when no SIZ box present"""
base = b'\xff\x4f\xff\x52' + b'\x00' * 38
assert {} == get_j2k_parameters(base + b'\x8F')
def test_not_j2k(self):
"""Test result when no JPEG2K SOF marker present"""
base = b'\xff\x4e\xff\x51' + b'\x00' * 38
assert {} == get_j2k_parameters(base + b'\x8F')