Re-ordered files.

stegano/basic.py

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+#!/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"
+
+from PIL import Image
+
+def hide(img, message):
+    """
+    Hide a message (string) in an image.
+
+    Use the red portion of a pixel (r, g, b) tuple to
+    hide the message string characters as ASCII values.
+    The red value of the first pixel is used for length of string.
+    """
+    length = len(message)
+    # Limit length of message to 255
+    if length > 255:
+        return False
+    # Use a copy of image to hide the text in
+    encoded = img.copy()
+    width, height = img.size
+    index = 0
+    for row in range(height):
+        for col in range(width):
+            (r, g, b) = img.getpixel((col, row))
+            # first value is length of message
+            if row == 0 and col == 0 and index < length:
+                asc = length
+            elif index <= length:
+                c = message[index -1]
+                asc = ord(c)
+            else:
+                asc = r
+            encoded.putpixel((col, row), (asc, g , b))
+            index += 1
+    return encoded
+
+def reveal(img):
+    """
+    Find a message in an image.
+
+    Check the red portion of an pixel (r, g, b) tuple for
+    hidden message characters (ASCII values).
+    The red value of the first pixel is used for length of string.
+    """
+    width, height = img.size
+    message = ""
+    index = 0
+    for row in range(height):
+        for col in range(width):
+            r, g, b = img.getpixel((col, row))
+            # First pixel r value is length of message
+            if row == 0 and col == 0:
+                length = r
+            elif index <= length:
+                message += chr(r)
+            index += 1
+    return message
+
+if __name__ == '__main__':
+    # Point of entry in execution mode.
+    from optparse import OptionParser
+    usage = "usage: %prog hide|reveal [options]"
+    parser = OptionParser(usage)
+    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.add_option("-s", "--secret", dest="secret",
+                    help="Your secret (Message, Image, Music or any binary file).")
+    parser.set_defaults(input_image_file = './pictures/Lenna.png',
+                        output_image_file = './pictures/Lenna_enc.png',
+                        secret = 'Hello World!')
+
+    (options, args) = parser.parse_args()
+
+    if sys.argv[1] == "hide":
+        img = Image.open(options.input_image_file)
+        img_encoded = hide(img, options.secret)
+        img_encoded.save(options.output_image_file)
+
+    elif sys.argv[1] == "reveal":
+        img = Image.open(options.input_image_file)
+        print reveal(img)