Created
March 5, 2017 20:37
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Hide text in images using steganography!
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"""A program that encodes and decodes hidden messages in images through LSB steganography""" | |
from PIL import Image, ImageFont, ImageDraw | |
import textwrap | |
def decode_image(file_location="images/encoded_sample.png"): | |
"""Decodes the hidden message in an image | |
file_location: the location of the image file to decode. By default is the provided encoded image in the images folder | |
""" | |
encoded_image = Image.open(file_location) | |
red_channel = encoded_image.split()[0] | |
x_size = encoded_image.size[0] | |
y_size = encoded_image.size[1] | |
decoded_image = Image.new("RGB", encoded_image.size) | |
pixels = decoded_image.load() | |
for i in range(x_size): | |
for j in range(y_size): | |
if bin(red_channel.getpixel((i, j)))[-1] == '0': | |
pixels[i, j] = (255, 255, 255) | |
else: | |
pixels[i, j] = (0,0,0) | |
decoded_image.save("images/decoded_image.png") | |
def write_text(text_to_write, image_size): | |
"""Writes text to an RGB image. Automatically line wraps | |
text_to_write: the text to write to the image | |
""" | |
image_text = Image.new("RGB", image_size) | |
font = ImageFont.load_default().font | |
drawer = ImageDraw.Draw(image_text) | |
#Text wrapping. Change parameters for different text formatting | |
margin = offset = 10 | |
for line in textwrap.wrap(text_to_write, width=60): | |
drawer.text((margin,offset), line, font=font) | |
offset += 10 | |
return image_text | |
def encode_image(text_to_encode, template_image="images/samoyed.jpg"): | |
"""Encodes a text message into an image | |
text_to_encode: the text to encode into the template image | |
template_image: the image to use for encoding. An image is provided by default. | |
""" | |
template_image = Image.open(template_image) | |
red_template = template_image.split()[0] | |
green_template = template_image.split()[1] | |
blue_template = template_image.split()[2] | |
x_size = template_image.size[0] | |
y_size = template_image.size[1] | |
#text draw | |
image_text = write_text(text_to_encode, template_image.size) | |
bw_encode = image_text.convert('1') | |
#encode text into image | |
encoded_image = Image.new("RGB", (x_size, y_size)) | |
pixels = encoded_image.load() | |
for i in range(x_size): | |
for j in range(y_size): | |
red_template_pix = bin(red_template.getpixel((i,j))) | |
old_pix = red_template.getpixel((i,j)) | |
tencode_pix = bin(bw_encode.getpixel((i,j))) | |
if tencode_pix[-1] == '1': | |
red_template_pix = red_template_pix[:-1] + '1' | |
else: | |
red_template_pix = red_template_pix[:-1] + '0' | |
pixels[i, j] = (int(red_template_pix, 2), green_template.getpixel((i,j)), blue_template.getpixel((i,j))) | |
encoded_image.save("images/encoded_image.png") | |
if __name__ == '__main__': | |
decode_image() | |
encode_image("hello world") |
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