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https://github.com/KevinMidboe/knowit_julekalender-2018.git
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88 lines
3.5 KiB
Python
88 lines
3.5 KiB
Python
"""A program that encodes and decodes hidden messages in images through LSB steganography"""
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from PIL import Image, ImageFont, ImageDraw
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import textwrap
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def decode_image(file_location="images/encoded_sample.png"):
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"""Decodes the hidden message in an image
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file_location: the location of the image file to decode. By default is the provided encoded image in the images folder
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"""
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encoded_image = Image.open(file_location)
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red_channel = encoded_image.split()[0]
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green_channel = encoded_image.split()[1]
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blue_channel = encoded_image.split()[2]
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x_size = encoded_image.size[0]
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y_size = encoded_image.size[1]
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decoded_image = Image.new("RGB", encoded_image.size)
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pixels = decoded_image.load()
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for i in range(x_size):
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for j in range(y_size):
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r_pixel = red_channel.getpixel((i,j))
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g_pixel = green_channel.getpixel((i,j))
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b_pixel = blue_channel.getpixel((i,j))
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# if pixels[i, j] = r_pixel, g_pixel, b_pixel ? bin(red_pixel)[-1] == '0':
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if bin(r_pixel)[-1] == '0' or bin(g_pixel)[-1] == '0' or bin(b_pixel)[-1] == '0':
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pixels[i, j] = (r_pixel, g_pixel, b_pixel)
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else:
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pixels[i, j] = (255,255,255)
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decoded_image.save("images/decoded_image.png")
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def write_text(text_to_write, image_size):
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"""Writes text to an RGB image. Automatically line wraps
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text_to_write: the text to write to the image
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"""
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image_text = Image.new("RGB", image_size)
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font = ImageFont.load_default().font
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drawer = ImageDraw.Draw(image_text)
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#Text wrapping. Change parameters for different text formatting
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margin = offset = 10
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for line in textwrap.wrap(text_to_write, width=60):
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drawer.text((margin,offset), line, font=font)
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offset += 10
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return image_text
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def encode_image(text_to_encode, template_image="images/samoyed.jpg"):
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"""Encodes a text message into an image
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text_to_encode: the text to encode into the template image
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template_image: the image to use for encoding. An image is provided by default.
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"""
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template_image = Image.open(template_image)
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red_template = template_image.split()[0]
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green_template = template_image.split()[1]
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blue_template = template_image.split()[2]
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x_size = template_image.size[0]
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y_size = template_image.size[1]
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#text draw
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image_text = write_text(text_to_encode, template_image.size)
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bw_encode = image_text.convert('1')
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#encode text into image
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encoded_image = Image.new("RGB", (x_size, y_size))
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pixels = encoded_image.load()
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for i in range(x_size):
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for j in range(y_size):
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red_template_pix = bin(red_template.getpixel((i,j)))
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green_template_pix = bin(green_template.getpixel((i,j)))
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blue_template_pix = bin(blue_template.getpixel((i,j)))
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tencode_pix = bin(bw_encode.getpixel((i,j)))
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if tencode_pix[-1] == '1':
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red_template_pix = red_template_pix[:-1] + '1'
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green_template_pix = green_template_pix[:-1] + '1'
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blue_template_pix = blue_template_pix[:-1] + '1'
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else:
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red_template_pix = red_template_pix[:-1] + '0'
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green_template_pix = green_template_pix[:-1] + '0'
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blue_template_pix = blue_template_pix[:-1] + '0'
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pixels[i, j] = (int(red_template_pix, 1), int(green_template_pix, 1), int(blue_template_pix, 1))
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encoded_image.save("images/encoded_image.png")
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if __name__ == '__main__':
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decode_image()
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# encode_image("hello world") |