hide_image_in_image.py

"""
This application hides an image inside another image.
It can be done using either 1 or 2 color pixels.
The application can also decode the image and retrive the hidden image.

NOTICE! when encoding you must use .jpg formats.

Example use of application (encode):
    An example of the use, where we want to encode a the private.jpg image in the public.jpg.
    We use encode2, to tell the application we want to use 2 color pixels.

    Command: python hideInImage.py encode2 public.jpg private.jpg
    Output: secret.png

Example use of application (decode):
    Here we want to decode the encoded image named secret.png.
    We use decode2 beacus we used to color pixels of the image.
    It will then output the hidden image inside the secret.png.

    Command: python hideInImage.py decode2 secret.png
    Output: output.png

TODO:
 - Make it possible to take .png files too

Author: Mathias Nicolajsen (TidosDK)
"""

# Imported libraries
import sys
from PIL import Image


def encode_1(public_image, private_image):  # Encoding function for 1 color pixel - Takes two arguments
    """
    This function encodes the private_image inside the public_image.
    It uses 1 color pixel.
    """

    public_img = Image.open(public_image)  # Gets information for the public image
    private_img = Image.open(private_image)  # Gets information for the private image
    x_public_max = public_img.size[0]  # The max for the public image on the x-coordinate
    x_public = 0
    y_public = 0

    # Gets the size information for the private image:
    width = '{0:016b}'.format(private_img.size[0])
    height = '{0:016b}'.format(private_img.size[1])

    for i in range(1, 17):  # Saves the width for the private image
        if x_public == x_public_max:
            y_public += 1
            x_public = 0

        size_x = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[:7] + '{0}'.format(int(width[i-1]))
        other_colors = public_img.getpixel((x_public, y_public))
        public_img.putpixel((x_public, y_public), (int(size_x, 2), other_colors[1], other_colors[2]))
        x_public += 1

    for i in range(1, 17):  # Save the height for the private image
        if x_public == x_public_max:
            y_public += 1
            x_public = 0

        size_y = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[:7] + '{0}'.format(int(height[i-1]))
        other_colors = public_img.getpixel((x_public, y_public))
        public_img.putpixel((x_public, y_public), (int(size_y, 2), other_colors[1], other_colors[2]))
        x_public += 1

    for x in range(private_img.size[0]):
        for y in range(private_img.size[1]):

            red_private = '{0:08b}'.format(private_img.getpixel((x, y))[0])  # Converts red color to binary
            for i in range(1, 9):  # Red
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0
                red = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[:7] + '{0}'.format(int(red_private[i-1]))
                other_colors = public_img.getpixel((x_public, y_public))
                public_img.putpixel((x_public, y_public), (int(red, 2), other_colors[1], other_colors[2]))
                x_public += 1

            green_private = '{0:08b}'.format(private_img.getpixel((x, y))[1])  # Converts green color to binary
            for i in range(1, 9):  # Green
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0
                green = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[1])[:7] + '{0}'.format(int(green_private[i-1]))
                other_colors = public_img.getpixel((x_public, y_public))
                public_img.putpixel((x_public, y_public), (other_colors[0], int(green, 2), other_colors[2]))
                x_public += 1

            blue_private = '{0:08b}'.format(private_img.getpixel((x, y))[2])  # Converts blue color to binary
            for i in range(1, 9):  # Blue
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0
                blue = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[2])[:7] + '{0}'.format(int(blue_private[i-1]))
                other_colors = public_img.getpixel((x_public, y_public))
                public_img.putpixel((x_public, y_public), (other_colors[0], other_colors[1], int(blue, 2)))
                x_public += 1

    return public_img  # Returns the public image with the private image inside.


def decode_1(encoded_image):  # Decoding function for 1 color pixel - Takes one argument
    """
    This function decodes the image inside another image.
    It only reads 1 color pixel.
    """

    public_img = Image.open(encoded_image)  # Gets information for public image
    x_public_max = public_img.size[0]
    x_public = 0
    y_public = 0

    x_private_size = ""
    y_private_size = ""

    for _ in range(1, 17):
        if x_public == x_public_max:
            y_public += 1
            x_public = 0

        x_private_size += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[-1]
        x_public += 1

    for _ in range(1, 17):
        if x_public == x_public_max:
            y_public += 1
            x_public = 0

        y_private_size += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[-1]
        x_public += 1

    private_img = Image.new("RGB", (int(x_private_size, 2), int(y_private_size, 2)))

    for x in range(int(x_private_size, 2)):  # Loops through the x-coordinate for public image.
        for y in range(int(y_private_size, 2)):  # Loops through the y-coordinate for public image.
            red = ""
            green = ""
            blue = ""

            for _ in range(1, 9):  # Red
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0

                red += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[-1]
                x_public += 1

            for _ in range(1, 9):  # Green
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0

                green += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[1])[-1]
                x_public += 1

            for _ in range(1, 9):  # Blue
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0

                blue += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[2])[-1]
                x_public += 1

            private_img.putpixel((x, y), (int(red, 2), int(green, 2), int(blue, 2)))

    return private_img


# Encode function with 2 color pixels


def encode_2(public_image, private_image):  # Function for encoding image
    """
    This function encodes the private_image inside the public_image.
    It uses 2 color pixel.
    """

    public_img = Image.open(public_image)  # Gets information for public image
    private_img = Image.open(private_image)  # Gets information for private image
    x_public_max = public_img.size[0]
    x_public = 0
    y_public = 0
    x_size = '{0:016b}'.format(private_img.size[0])
    y_size = '{0:016b}'.format(private_img.size[1])

    for l in range(1, 16, 2):
        if x_public == x_public_max:
            y_public += 1
            x_public = 0

        size_x = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[:6] + '{0}'.format(str(x_size[l-1:l+1]))
        other_colors = public_img.getpixel((x_public, y_public))
        public_img.putpixel((x_public, y_public), (int(size_x, 2), other_colors[1], other_colors[2]))
        x_public += 1

    for l in range(1, 16, 2):  # Image size y
        if x_public == x_public_max:
            y_public += 1
            x_public = 0

        size_y = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[:6] + '{0}'.format(str(y_size[l-1:l+1]))
        other_colors = public_img.getpixel((x_public, y_public))
        public_img.putpixel((x_public, y_public), (int(size_y, 2), other_colors[1], other_colors[2]))
        x_public += 1

    for x in range(private_img.size[0]):
        for y in range(private_img.size[1]):

            red_private = '{0:08b}'.format(private_img.getpixel((x, y))[0])  # Converts red color to binary

            for l in range(1, 8, 2):  # Red
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0
                red = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[:6] + '{0}'.format(str(red_private[l-1:l+1]))
                other_colors = public_img.getpixel((x_public, y_public))
                public_img.putpixel((x_public, y_public), (int(red, 2), other_colors[1], other_colors[2]))
                x_public += 1

            green_private = '{0:08b}'.format(private_img.getpixel((x, y))[1])  # Converts green color to binary
            for l in range(1, 8, 2):  # Green
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0
                green = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[1])[:6] + '{0}'.format(str(green_private[l-1:l+1]))
                other_colors = public_img.getpixel((x_public, y_public))
                public_img.putpixel((x_public, y_public), (other_colors[0], int(green, 2), other_colors[2]))
                x_public += 1

            blue_private = '{0:08b}'.format(private_img.getpixel((x, y))[2])  # Converts blue color to binary
            for l in range(1, 8, 2):  # Blue
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0
                blue = '{0:08b}'.format(public_img.getpixel((x_public, y_public))[2])[:6] + '{0}'.format(str(blue_private[l-1:l+1]))
                other_colors = public_img.getpixel((x_public, y_public))
                public_img.putpixel((x_public, y_public), (other_colors[0], other_colors[1], int(blue, 2)))
                x_public += 1

    return public_img  # Returns the public image with the private image inside.


def decode_2(public_image):  # Function for decoding image
    """
    This function decodes the image inside another image.
    It only reads 2 color pixel.
    """

    public_img = Image.open(public_image)  # Gets information for public image
    x_public_max = public_img.size[0]
    x_public = 0
    y_public = 0

    x_private_size = ""
    y_private_size = ""

    for _ in range(1, 16, 2):
        if x_public == x_public_max:
            y_public += 1
            x_public = 0
        x_private_size += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[-2:8]
        x_public += 1

    for _ in range(1, 16, 2):
        if x_public == x_public_max:
            y_public += 1
            x_public = 0
        y_private_size += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[-2:8]
        x_public += 1

    print(int(x_private_size, 2), int(y_private_size, 2))

    private_img = Image.new("RGB", (int(x_private_size, 2), int(y_private_size, 2)))
    for x in range(int(x_private_size, 2)):  # Loops through the x-coordinate for public image.
        for y in range(int(y_private_size, 2)):  # Loops through the y-coordinate for public image.
            red = ""
            green = ""
            blue = ""
            for _ in range(1, 5):  # Red
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0

                red += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[0])[-2:8]
                x_public += 1

            for _ in range(1, 5):  # Green
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0

                green += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[1])[-2:8]
                x_public += 1

            for _ in range(1, 5):  # Blue
                if x_public == x_public_max:
                    y_public += 1
                    x_public = 0

                blue += '{0:08b}'.format(public_img.getpixel((x_public, y_public))[2])[-2:8]
                x_public += 1

            private_img.putpixel((x, y), (int(red, 2), int(green, 2), int(blue, 2)))

    return private_img


if len(sys.argv) >= 4:
    if sys.argv[1] == "encode1":
        temp_public_img = Image.open(sys.argv[2])
        temp_private_img = Image.open(sys.argv[3])
        temp_public_size = temp_public_img.size[0] * temp_public_img.size[1]
        temp_private_img = temp_private_img.size[0] * temp_private_img.size[1]
        if temp_public_size > temp_private_img * 24:
            print("Private image can fit inside the public.")
            print("Begins to encode the private image in the public...\n")

            encode_1(sys.argv[2], sys.argv[3]).save("secret.png")
            print("Image has successfully been saved as secret.png")
        else:
            print("ERROR: Private image is too bit to fit")

    elif sys.argv[1] == "encode2":
        temp_public_img = Image.open(sys.argv[2])
        temp_private_img = Image.open(sys.argv[3])
        temp_public_size = temp_public_img.size[0] * temp_public_img.size[1]
        temp_private_img = temp_private_img.size[0] * temp_private_img.size[1]
        if temp_public_size > temp_private_img * 12:
            print("Private image can fit inside the public.")
            print("Begins to encode the private image in the public...\n")

            encode_2(sys.argv[2], sys.argv[3]).save("secret.png")
            print("Image has successfully been saved as secret.png")
        else:
            print("ERROR: Private image is too bit to fi,")

elif len(sys.argv) >= 3:
    if sys.argv[1] == "decode1":
        print("Make sure you used the right color pixel argument")
        print("Application will now decode the image...\n")

        decode_1(sys.argv[2]).save("output.png")
        print("Image has been saved as output.png")

    elif sys.argv[1] == "decode2":
        print("Make sure you used the right color pixel argument")
        print("Application will now decode the image...\n")

        decode_2(sys.argv[2]).save("output.png")
        print("Image has been saved as output.png")

else:
    print("The right uses:")
    print("1 color pixel:")
    print(" - Python file.py encode1 img1 img2")
    print(" - Python file.py decode1 img")
    print("\n2 color pixels:")
    print(" - Python file.py encode2 img1 img2")
    print(" - Python file.py decode2 img")