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https://github.com/cedricbonhomme/Stegano.git
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99 lines
No EOL
2.9 KiB
Python
99 lines
No EOL
2.9 KiB
Python
#! /usr/local/bin/python
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#-*- coding: utf-8 -*-
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__author__ = "Cedric Bonhomme"
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__version__ = "$Revision: 0.1 $"
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__date__ = "$Date: 2010/10/01 $"
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import tools
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from PIL import Image
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def hide(img, message):
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"""
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Hide a message (string) in an image with the
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LSB (Less Significant Bit) technic.
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"""
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encoded = img.copy()
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width, height = img.size
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index = 0
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message = message + '~~~'
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message_bits = tools.a2bits(message)
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for row in range(height):
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for col in range(width):
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if index + 3 <= len(message_bits) :
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(r, g, b) = img.getpixel((col, row))
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# Convert in to bits
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r_bits = tools.bs(r)
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g_bits = tools.bs(g)
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b_bits = tools.bs(b)
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# Replace (in a list) the least significant bit
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# by the bit of the message to hide
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list_r_bits = list(r_bits)
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list_g_bits = list(g_bits)
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list_b_bits = list(b_bits)
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list_r_bits[-1] = message_bits[index]
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list_g_bits[-1] = message_bits[index + 1]
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list_b_bits[-1] = message_bits[index + 2]
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# Convert lists to a strings
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r_bits = "".join(list_r_bits)
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g_bits = "".join(list_g_bits)
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b_bits = "".join(list_b_bits)
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# Convert strings of bits to int
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r = int(r_bits, 2)
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g = int(g_bits, 2)
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b = int(b_bits, 2)
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# Save the new pixel
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encoded.putpixel((col, row), (r, g , b))
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index += 3
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return encoded
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def reveal(img):
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"""
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Find a message in an image (with the
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LSB technic).
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"""
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width, height = img.size
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bits = ""
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index = 0
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for row in range(height):
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for col in range(width):
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r, g, b = img.getpixel((col, row))
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bits += tools.bs(r)[-1] + tools.bs(g)[-1] + tools.bs(b)[-1]
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if len(bits) >= 8:
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if chr(int(bits[-8:], 2)) == '~':
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list_of_string_bits = ["".join(list(bits[i*8:(i*8)+8])) for i in range(0, len(bits)/8)]
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list_of_character = [chr(int(elem, 2)) for elem in list_of_string_bits]
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return "".join(list_of_character)[:-1]
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return ""
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if __name__ == '__main__':
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# Point of entry in execution mode
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original_image_file = "./pictures/Lenna.png"
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encoded_image_file = "Lenna_enc.png"
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secret_message = "Avec la technique LSB (Least Significant Bit) l'oeil humain (un normal ;-)) ne voit plus la difference!"
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img1 = Image.open(original_image_file)
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img_encoded = hide(img1, secret_message)
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if img_encoded:
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# Save it
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img_encoded.save(encoded_image_file)
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# Test it
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img2 = Image.open(encoded_image_file)
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print reveal(img2) |