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https://github.com/cedricbonhomme/Stegano.git
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79 lines
No EOL
2.3 KiB
Python
79 lines
No EOL
2.3 KiB
Python
# -*- 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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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.
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Use the red portion of a pixel (r, g, b) tuple to
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hide the message string characters as ASCII values.
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The red value of the first pixel is used for length of string.
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"""
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length = len(message)
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# limit length of message to 255
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if length > 255:
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return False
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# use a copy of image to hide the text in
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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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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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# first value is length of message
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if row == 0 and col == 0 and index < length:
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asc = length
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elif index <= length:
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c = message[index -1]
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asc = ord(c)
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else:
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asc = r
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encoded.putpixel((col, row), (asc, g , b))
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index += 1
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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.
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Check the red portion of an pixel (r, g, b) tuple for
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hidden message characters (ASCII values).
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The red value of the first pixel is used for length of string.
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"""
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width, height = img.size
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message = ""
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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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# first pixel r value is length of message
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if row == 0 and col == 0:
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length = r
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elif index <= length:
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message += chr(r)
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index += 1
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return message
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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 = "./pictures/Lenna_enc.png"
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# at this point don't exceed 255 characters
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secret_message = "Parce que je le vaut bien!"
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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)
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else:
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print("text too long! (don't exeed 255 characters)") |