secret_txt_in_png

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Filename: secret_txt_in_png.py
# Version: 1.0.0
# Author: Jeoi Reqi

"""
Description:
    - This script provides functionalities for encoding and decoding images to and from text files.
    - Additionally, it can combine images and additional text into a single text file and extract them back.
    - It supports encoding images into base64 strings, saving them as text files, and decoding base64 strings back into images.
    - The script includes a feature allowing users to embed extra text alongside an image.
    - This feature is beneficial for adding metadata or annotations.

Requirements:
    - Python 3.x
    - tkinter (standard library module for GUI dialogs)

Functions:
    - select_file(title, filetypes):
        Opens a file dialog to select a file.
    - save_file_as(title, defaultextension, filetypes):
        Opens a file dialog to save a file.
    - encode_image(image_file_path):
        Encodes an image to a base64 string.
    - save_text_file(file_path, content):
        Saves text content to a file.
    - read_text_file(file_path):
        Reads text content from a file.
    - decode_image(encoded_string):
        Decodes a base64 string to image binary data.
    - save_image(file_path, image_data, format='png'):
        Saves image binary data to a file with optional format specification.
    - check_file_size(file_path):
        Checks if the file size exceeds the maximum allowed size.
    - print_help(): Prints a detailed help menu.
    - convert_image_to_text():
        Converts an image file to a text file with encoded base64 data.
    - convert_text_to_image():
        Converts a text file with encoded base64 data back to an image file.
    - encode_image_and_text_to_text():
        Encodes an image and additional text into a single text file.
    - extract_image_and_text_from_text():
        Extracts an image and additional text from a combined text file.

Usage:
    - Run the script and follow the prompts in the console.
    - Choose from the menu options to perform various operations on images and text files.

Additional Notes:
    - This script uses Python's tkinter module for file dialogs, which is standard in most Python installations.
    - Error handling is implemented to log errors to 'image_processing.log' for debugging purposes.
    - Maximum file size for encoding is set to 10 MB to prevent performance issues with large files.
"""

# Get essential imports
import base64
import os
import logging
from tkinter import Tk
from tkinter.filedialog import askopenfilename, asksaveasfilename

# Configure logging to file
logging.basicConfig(filename='image_processing.log', level=logging.ERROR)

# Set max file size limit
MAX_FILE_SIZE_MB = 10  # Maximum file size in megabytes (MB) converted to bytes

def select_file(title, filetypes):
    """
    Opens a file dialog to select a file.

    Parameters:
    - title (str): The title of the file dialog window.
    - filetypes (list of tuples): Each tuple contains a description and file extension pattern.

    Returns:
    - str: The path of the selected file.
    """
    return askopenfilename(title=title, filetypes=filetypes)

def save_file_as(title, defaultextension, filetypes):
    """
    Open a file dialog to save a file.

    Parameters:
    - title (str): The title of the file dialog window.
    - defaultextension (str): The default file extension to append if none provided by the user.
    - filetypes (list of tuples): Each tuple contains a description and file extension pattern.

    Returns:
    - str or None: The path of the selected file, or None if the user cancels the operation.
    """
    return asksaveasfilename(title=title, defaultextension=defaultextension, filetypes=filetypes)

def encode_image(image_file_path):
    """
    Encode an image to a base64 string.

    Parameters:
    - image_file_path (str): The path to the image file to be encoded.

    Returns:
    - str or None: The base64 encoded string of the image data, or None if an error occurs.
    """
    try:
        with open(image_file_path, 'rb') as image_file:
            image_data = image_file.read()
            total_size = len(image_data)
            encoded_data = base64.b64encode(image_data).decode('utf-8')

            # Print progress
            print(f"\nEncoding progress: {total_size} bytes\n")

            return encoded_data
    except Exception as e:
        logging.error(f"\n!Error encoding image: {e}\n")
        print(f"\n!Error encoding image: {e}\n")
        return None

def save_text_file(file_path, content):
    """
    Save text content to a file.

    Parameters:
    - file_path (str): The path to the file where content will be saved.
    - content (str): The text content to be saved.
    """
    try:
        with open(file_path, 'w', encoding='utf-8') as text_file:
            text_file.write(content)
    except Exception as e:
        logging.error(f"\n!Error saving text file: {e}\n")
        print(f"\n!Error saving text file: {e}\n")

def read_text_file(file_path):
    """
    Read text content from a file.

    Parameters:
    - file_path (str): The path to the file from which content will be read.

    Returns:
    - str or None: The content read from the file, or None if an error occurs.
    """
    try:
        with open(file_path, 'r', encoding='utf-8') as text_file:
            return text_file.read()
    except Exception as e:
        logging.error(f"\n!Error reading text file: {e}\n")
        print(f"\n!Error reading text file: {e}\n")
        return None

def decode_image(encoded_string):
    """
    Decode a base64 string to image binary data.

    Parameters:
    - encoded_string (str): The base64 encoded string to be decoded.

    Returns:
    - bytes or None: The binary data of the decoded image, or None if an error occurs.
    """
    try:
        return base64.b64decode(encoded_string)
    except Exception as e:
        logging.error(f"\n!Error decoding image: {e}\n")
        print(f"\n!Error decoding image: {e}\n")
        return None

def save_image(file_path, image_data, format='png'):
    """
    Save image binary data to a file with optional format specification.

    Parameters:
    - file_path (str): The path to the file where image data will be saved.
    - image_data (bytes): The binary data of the image to be saved.
    - format (str): Optional. The format of the image file ('png', 'jpeg', 'bmp'). Default is 'png'.
    """
    try:
        if not file_path.endswith(f'.{format}'):
            file_path += f'.{format}'
        with open(file_path, 'wb') as image_file:
            image_file.write(image_data)
    except Exception as e:
        logging.error(f"\n!Error saving image file: {e}\n")
        print(f"\n!Error saving image file: {e}\n")

def check_file_size(file_path):
    """
    Check if the file size exceeds the maximum allowed size.

    Parameters:
    - file_path (str): The path to the file to check.

    Notes:
    - If the file size exceeds the allowed limit (MAX_FILE_SIZE_MB), a warning message is printed.
    """
    try:
        file_size = os.path.getsize(file_path)
        if file_size > MAX_FILE_SIZE_MB * 1024 * 1024:
            print(f"\n!Warning!: File size ({file_size / (1024 * 1024):.2f} MB) exceeds {MAX_FILE_SIZE_MB} MB! Proceed with caution!\n")
    except Exception as e:
        logging.error(f"\n!Error checking file size: {e}\n")
        print(f"\n!Error checking file size: {e}\n")

def print_help():
    """
    Print detailed help menu.
    """
    print("\nHelp Menu:\n")
    print("1. Convert image to text file:\nEncodes an image to a base64 string and saves it as a text file.\n")
    print("2. Convert text file to image:\nDecodes a base64 string from a text file and saves it as an image.\n")
    print("3. Encode image & text to text file:\nEncodes an image and additional text together into a text file.\n")
    print("4. Extract image & text from text file:\nExtracts an image and additional text from a text file.\n")
    print("5. Help: Print this help menu.\n")
    print("0. Exit: Quit the program.\n")

def convert_image_to_text():
    """
    Convert an image file to a text file with encoded base64 data.
    """
    image_file_path = select_file("Select Image File", [("Image Files", "*.jpg;*.jpeg;*.png;*.gif;*.bmp")])
    if not image_file_path:
        print("\nNo file selected! Operation cancelled.")
        return

    text_file_path = save_file_as("Save Encoded Text As", ".txt", [("Text Files", "*.txt")])
    if not text_file_path:
        print("\nNo file selected! Operation cancelled.")
        return

    encoded_string = encode_image(image_file_path)
    if encoded_string:
        save_text_file(text_file_path, encoded_string)
        print(f"\nImage encoded and saved to {text_file_path}\n")

def convert_text_to_image():
    """
    Convert a text file with encoded base64 data back to an image file.
    """
    text_file_path = select_file("Select Text File", [("Text Files", "*.txt")])
    if not text_file_path:
        print("\nNo file selected! Operation cancelled.")
        return

    output_image_path = save_file_as("Save Image As", ".png", [("PNG Files", "*.png"), ("JPEG Files", "*.jpg"), ("BMP Files", "*.bmp")])
    if not output_image_path:
        print("\nNo file selected! Operation cancelled.")
        return

    encoded_string = read_text_file(text_file_path)
    if encoded_string:
        image_data = decode_image(encoded_string)
        if image_data:
            # Determine output format based on file extension
            format = output_image_path.split('.')[-1]
            save_image(output_image_path, image_data, format=format)
            print(f"\nImage decoded and saved to {output_image_path}\n")

def encode_image_and_text_to_text():
    """
    Encode an image and additional text together into a text file.
    """
    image_file_path = select_file("Select Image File", [("Image Files", "*.jpg;*.jpeg;*.png;*.gif;*.bmp")])
    if not image_file_path:
        print("\nNo file selected! Operation cancelled.")
        return

    additional_text = input("\nEnter additional text to encode: ")

    text_file_path = save_file_as("Save Encoded Text As", ".txt", [("Text Files", "*.txt")])
    if not text_file_path:
        print("\nNo file selected! Operation cancelled.")
        return

    encoded_string = encode_image(image_file_path)
    if encoded_string:
        combined_content = f"{additional_text}\n--delimiter--\n{encoded_string}"
        save_text_file(text_file_path, combined_content)
        print(f"\nImage and additional text encoded and saved to {text_file_path}\n")

def extract_image_and_text_from_text():
    """
    Extract an image and additional text from a combined text file.
    """
    text_file_path = select_file("Select Text File", [("Text Files", "*.txt")])
    if not text_file_path:
        print("\nNo file selected! Operation cancelled.")
        return

    output_image_path = save_file_as("Save Image As", ".png", [("PNG Files", "*.png"), ("JPEG Files", "*.jpg"), ("BMP Files", "*.bmp")])
    if not output_image_path:
        print("\nNo file selected! Operation cancelled.")
        return

    combined_content = read_text_file(text_file_path)
    if combined_content:
        try:
            additional_text, encoded_string = combined_content.split('--delimiter--\n')
            image_data = decode_image(encoded_string)
            if image_data:
                # Determine output format based on file extension
                format = output_image_path.split('.')[-1]
                save_image(output_image_path, image_data, format=format)
                print(f"\nImage decoded and saved to {output_image_path}\n")
                print(f"\nAdditional text: {additional_text}\n")
        except ValueError:
            print("\n!Error: Text file does not contain valid delimiter!\n")

if __name__ == "__main__":
    # Hide the root Tk window
    root = Tk()
    root.withdraw()

    while True:
        print("_" * 40)
        print("\n\t:: Main Menu ::\n")
        print("1. Convert image to text file")
        print("2. Convert text file to image")
        print("3. Encode image & text to text file")
        print("4. Extract image & text from text file")
        print("5. Help Menu")
        print("0. Exit")
        print("_" * 40)

        choice = input("\nEnter your choice: ")
        print("_" * 40)

        if choice == '1':
            convert_image_to_text()
        elif choice == '2':
            convert_text_to_image()
        elif choice == '3':
            encode_image_and_text_to_text()
        elif choice == '4':
            extract_image_and_text_from_text()
        elif choice == '5':
            print_help()
        elif choice == '0':
            print("\nExiting Program...   GoodBye!\n")
            break
        else:
            print("\nInvalid choice! Please try again.\n")