Added binary for parity steganalysis.

stegano/steganalysisStatistics.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+#-*- coding: utf-8 -*-
+
+# Stéganô - Stéganô is a basic Python Steganography module.
+# Copyright (C) 2010-2011  Cédric Bonhomme - http://cedricbonhomme.org/
+#
+# For more information : http://bitbucket.org/cedricbonhomme/stegano/
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>
+
+__author__ = "Cedric Bonhomme"
+__version__ = "$Revision: 0.1 $"
+__date__ = "$Date: 2010/10/01 $"
+__license__ = "GPLv3"
+
+import operator
+
+from PIL import Image
+from collections import Counter
+from collections import OrderedDict
+
+def steganalyse(img):
+    """
+    Steganlysis of the LSB technique.
+    """
+    encoded = img.copy()
+    width, height = img.size
+    colours = Counter()
+    for row in range(height):
+        for col in range(width):
+            r, g, b = img.getpixel((col, row))
+            colours[r] += 1
+
+    most_common = colours.most_common(10)
+    dict_colours = OrderedDict(sorted(colours.items(), key=lambda t: t[1]))
+
+    colours = 0
+    for colour in dict_colours.keys():
+        colours += colour
+    colours = colours / len(dict_colours)
+
+    #return colours.most_common(10)
+    return dict_colours.keys()[:30], most_common
+
+if __name__ == '__main__':
+    # Point of entry in execution mode.
+    from optparse import OptionParser
+    parser = OptionParser()
+    parser.add_option("-i", "--input", dest="input_image_file",
+                    help="Image file.")
+    parser.add_option("-o", "--output", dest="output_image_file",
+                    help="Image file.")
+    parser.set_defaults(input_image_file = './pictures/Lenna.png',
+                        output_image_file = './pictures/Lenna_steganalysed.png')
+    (options, args) = parser.parse_args()
+
+    input_image_file = Image.open(options.input_image_file)
+    output_image = steganalyse(input_image_file)
+    soutput_image.save(options.output_image_file)