Added steganalyse.py

LSB.py

@@ -15,15 +15,15 @@ def hide(img, message):
     LSB (Least Significant Bit) technique.
     """
     encoded = img.copy()
-    width, height = img.size    
+    width, height = img.size
     index = 0
 
-    message = message + '~~ '
+    message = message + '~~~'
     message_bits = tools.a2bits(message)
 
     npixels = width * height
     if len(message_bits) > npixels * 3:
-        return """To long message (%s > %s).""" % (len(message_bits), npixels * 3)
+        return """Too long message (%s > %s).""" % (len(message_bits), npixels * 3)
 
     for row in range(height):
         for col in range(width):
@@ -70,12 +70,46 @@ def reveal(img):
 
 if __name__ == '__main__':
     # Point of entry in execution mode
-    original_image_file = "./pictures/Lenna.png"
+    original_image_file = "./pictures/2010-08-04T15:42:06.png"
-    encoded_image_file = "Lenna_enc.png"
+    encoded_image_file = "./pictures/2010-08-04T15:42:06_enc.png"
     secret_message = "Avec la technique LSB (Least Significant Bit) l'oeil humain (un normal ;-))  ne voit plus la difference"
+    Lorem_ipsum = """\
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.    
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
+Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+"""
 
     img1 = Image.open(original_image_file)
-    img_encoded = hide(img1, secret_message)
+    img_encoded = hide(img1, Lorem_ipsum)
 
     if img_encoded:
         # Save it

steganalyse.py

@@ -0,0 +1,50 @@
+#! /usr/local/bin/python
+#-*- coding: utf-8 -*-
+
+__author__ = "Cedric Bonhomme"
+__version__ = "$Revision: 0.1 $"
+__date__ = "$Date: 2010/10/01 $"
+
+from PIL import Image
+
+def steganalyse(img):
+    """
+    Find a message in an image
+    (with the LSB technique).
+    """
+    encoded = img.copy()
+    width, height = img.size
+    bits = ""
+    for row in range(height):
+        for col in range(width):
+            r, g, b = img.getpixel((col, row))
+            if r % 2 == 0:
+                r = 0
+            else:
+                r = 255
+            if g % 2 == 0:
+                g = 0
+            else:
+                g = 255
+            if b % 2 == 0:
+                b = 0
+            else:
+                b = 255
+            encoded.putpixel((col, row), (r, g , b))
+    return encoded
+
+if __name__ == '__main__':
+    # Point of entry in execution mode
+    original_image_file = "./pictures/2010-08-04T15:42:06.png"
+    encoded_image_file = "./pictures/2010-08-04T15:42:06_enc.png"
+    original_image_file_steganalysed = "./pictures/2010-08-04T15:42:06_steganalysed.png"
+    encoded_image_file_steganalysed = "./pictures/2010-08-04T15:42:06_enc_steganalysed.png"
+
+    img_original_image_file = Image.open(original_image_file)
+    img_encoded_image_file = Image.open(encoded_image_file)
+
+    img_original_image_steganalysde = steganalyse(img_original_image_file)
+    img_encoded_image_steganalysed = steganalyse(img_encoded_image_file)
+
+    img_original_image_steganalysde.save(original_image_file_steganalysed)
+    img_encoded_image_steganalysed.save(encoded_image_file_steganalysed)