The generator provided to lsbset.hide() lsbset.reveal() is now a function. Closes #5.

bin/lsb-set

@@ -20,12 +20,14 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 __author__ = "Cedric Bonhomme"
-__version__ = "$Revision: 0.5 $"
+__version__ = "$Revision: 0.5.1 $"
 __date__ = "$Date: 2016/03/18 $"
+__revision__ = "$Date: 2016/05/22 $"
 __license__ = "GPLv3"
 
 try:
     from stegano import lsbset
+    from stegano.lsbset import generators
 except:
     print("Install stegano: sudo pip install Stegano")
 
@@ -67,6 +69,10 @@ parser.set_defaults(input_image_file = './pictures/Lenna.png',
 
 (options, args) = parser.parse_args()
 
+try:
+    generator = getattr(generators, options.generator_function)()
+except AttributeError as e:
+    raise e
 
 if options.hide:
     if options.secret_message != "" and options.secret_file == "":
@@ -74,7 +80,7 @@ if options.hide:
     elif options.secret_message == "" and options.secret_file != "":
         secret = tools.binary2base64(options.secret_file)
 
-    img_encoded = lsbset.hide(options.input_image_file, secret, options.generator_function)
+    img_encoded = lsbset.hide(options.input_image_file, secret, generator)
     try:
         img_encoded.save(options.output_image_file)
     except Exception as e:
@@ -83,7 +89,7 @@ if options.hide:
 
 elif options.reveal:
     try:
-        secret = lsbset.reveal(options.input_image_file, options.generator_function)
+        secret = lsbset.reveal(options.input_image_file, generator)
     except IndexError:
         print("Impossible to detect message.")
         exit(0)

stegano/lsbset/lsbset.py

@@ -20,8 +20,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 __author__ = "Cedric Bonhomme"
-__version__ = "$Revision: 0.4.1 $"
+__version__ = "$Revision: 0.4.2 $"
 __date__ = "$Date: 2016/03/13 $"
+__revision__ = "$Date: 2016/05/22 $"
 __license__ = "GPLv3"
 
 import sys
@@ -36,7 +37,7 @@ try:
 except NameError:
    pass
 
-def hide(input_image_file, message, generator_function, auto_convert_rgb=False):
+def hide(input_image_file, message, generator, auto_convert_rgb=False):
     """
     Hide a message (string) in an image with the
     LSB (Least Significant Bit) technique.
@@ -69,11 +70,6 @@ def hide(input_image_file, message, generator_function, auto_convert_rgb=False):
         raise Exception("The message you want to hide is too long: {}".\
                             format(message_length))
 
-    try:
-        generator = getattr(generators, generator_function)()
-    except AttributeError as e:
-        raise e
-
     while index + 3 <= len_message_bits :
         generated_number = next(generator)
         (r, g, b) = img_list[generated_number]
@@ -97,8 +93,7 @@ def hide(input_image_file, message, generator_function, auto_convert_rgb=False):
     return encoded
 
 
-
+def reveal(input_image_file, generator):
-def reveal(input_image_file, generator_function):
     """
     Find a message in an image
     (with the LSB technique).
@@ -110,8 +105,6 @@ def reveal(input_image_file, generator_function):
     bitab = []
     limit = None
 
-    generator = getattr(generators, generator_function)()
-
     while True:
         generated_number = next(generator)
         # color = [r, g, b]
@@ -178,6 +171,10 @@ if __name__ == '__main__':
 
     (options, args) = parser.parse_args()
 
+    try:
+        generator = getattr(generators, options.generator_function)()
+    except AttributeError as e:
+        raise e
 
     if options.hide:
         if options.secret_message != "" and options.secret_file == "":
@@ -185,7 +182,7 @@ if __name__ == '__main__':
         elif options.secret_message == "" and options.secret_file != "":
             secret = tools.binary2base64(options.secret_file)
 
-        img_encoded = hide(options.input_image_file, secret, options.generator_function)
+        img_encoded = hide(options.input_image_file, secret, generator)
         try:
             img_encoded.save(options.output_image_file)
         except Exception as e:
@@ -194,7 +191,7 @@ if __name__ == '__main__':
 
     elif options.reveal:
         try:
-            secret = reveal(options.input_image_file, options.generator_function)
+            secret = reveal(options.input_image_file, generator)
         except IndexError:
             print("Impossible to detect message.")
             exit(0)

tests/test_lsbset.py

@@ -20,14 +20,16 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 __author__ = "Cedric Bonhomme"
-__version__ = "$Revision: 0.1 $"
+__version__ = "$Revision: 0.2 $"
 __date__ = "$Date: 2016/04/13 $"
+__revision__ = "$Date: 2016/05/22 $"
 __license__ = "GPLv3"
 
 import os
 import unittest
 
 from stegano import lsbset
+from stegano.lsbset import generators
 
 class TestLSBSet(unittest.TestCase):
 
@@ -37,33 +39,34 @@ class TestLSBSet(unittest.TestCase):
         """
         with self.assertRaises(AssertionError):
             secret = lsbset.hide("./tests/sample-files/Lenna.png", "",
-                                    "eratosthenes")
+                                    generators.eratosthenes())
 
     def test_hide_and_reveal(self):
         messages_to_hide = ["a", "foo", "Hello World!", ":Python:"]
         for message in messages_to_hide:
             secret = lsbset.hide("./tests/sample-files/Lenna.png", message,
-                                    "eratosthenes")
+                                    generators.eratosthenes())
             secret.save("./image.png")
 
-            clear_message = lsbset.reveal("./image.png", "eratosthenes")
+            clear_message = lsbset.reveal("./image.png",
+                                    generators.eratosthenes())
 
             self.assertEqual(message, clear_message)
 
     def test_hide_and_reveal_with_bad_generator(self):
         message_to_hide = "Hello World!"
         secret = lsbset.hide("./tests/sample-files/Lenna.png", message_to_hide,
-                            "eratosthenes")
+                                    generators.eratosthenes())
         secret.save("./image.png")
 
         with self.assertRaises(IndexError):
-            clear_message = lsbset.reveal("./image.png", "identity")
+            clear_message = lsbset.reveal("./image.png", generators.identity())
 
     def test_with_unknown_generator(self):
         message_to_hide = "Hello World!"
         with self.assertRaises(AttributeError):
             secret = lsbset.hide("./tests/sample-files/Lenna.png",
-                                message_to_hide, "eratosthene")
+                                    message_to_hide, generators.eratosthene())
 
     def tearDown(self):
         try: