def test_encode_decode_msg_from_bit(self):
IMG = scipy.misc.lena()
MSG = 'This test works well'
# test with lsb
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG, stegobit=7)
msg = retrieve.decode_msg_from_bit(img_array=stego_img, stegobit=7)
self.assertEqual(MSG, msg)
# test with bit in between
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG, stegobit=4)
msg = retrieve.decode_msg_from_bit(img_array=stego_img, stegobit=4)
self.assertEqual(MSG, msg)
# test with msb
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG, stegobit=0)
msg = retrieve.decode_msg_from_bit(img_array=stego_img, stegobit=0)
self.assertEqual(MSG, msg)
def test_encode_decode_msg_from_bit(self):
IMG = scipy.misc.lena()
MSG = 'This test works well'
# test with lsb
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG, stegobit=7)
msg = retrieve.decode_msg_from_bit(img_array=stego_img, stegobit=7)
self.assertEqual(MSG, msg)
# test with bit in between
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG, stegobit=4)
msg = retrieve.decode_msg_from_bit(img_array=stego_img, stegobit=4)
self.assertEqual(MSG, msg)
# test with msb
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG, stegobit=0)
msg = retrieve.decode_msg_from_bit(img_array=stego_img, stegobit=0)
self.assertEqual(MSG, msg)
def test_constructed_strings(self):
IMG = scipy.misc.lena()
MSG1 = 'Steganography has no chance'
MSG2 = 'Really really no chance'
# first, hide two messages in the same image
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG1, stegobit=7)
stego_img = hide.encode_msg_in_bit(img_array=stego_img, msg=MSG2,
stegobit=5)
# then, check if we get it back out
msgs1 = analyse.constructed_strings(img_array=stego_img, threshold=4)
msgs1 = list(msgs1)
self.assertIn(MSG1, msgs1)
self.assertIn(MSG2, msgs1)
# test with a higher threshold (fewer garbage strings)
msgs2 = analyse.constructed_strings(img_array=stego_img, threshold=14)
msgs2 = list(msgs2)
self.assertIn(MSG1, msgs2)
self.assertIn(MSG2, msgs2)
# we should get a lot fewer results for a higher threshold
self.assertTrue(len(msgs1) > len(msgs2))
def test_constructed_strings(self):
IMG = scipy.misc.lena()
MSG1 = 'Steganography has no chance'
MSG2 = 'Really really no chance'
# first, hide two messages in the same image
stego_img = hide.encode_msg_in_bit(img_array=IMG, msg=MSG1, stegobit=7)
stego_img = hide.encode_msg_in_bit(img_array=stego_img,
msg=MSG2,
stegobit=5)
# then, check if we get it back out
msgs1 = analyse.constructed_strings(img_array=stego_img, threshold=4)
msgs1 = list(msgs1)
self.assertIn(MSG1, msgs1)
self.assertIn(MSG2, msgs1)
# test with a higher threshold (fewer garbage strings)
msgs2 = analyse.constructed_strings(img_array=stego_img, threshold=14)
msgs2 = list(msgs2)
self.assertIn(MSG1, msgs2)
self.assertIn(MSG2, msgs2)
# we should get a lot fewer results for a higher threshold
self.assertTrue(len(msgs1) > len(msgs2))
def test_msg_too_long_for_image(self):
with self.assertRaises(AssertionError):
hide.encode_msg_in_bit(img_array=lena(), msg="A" * (lena().size + 1), stegobit=3)
