St. Egano - Steganography Decoder

This project is a Java application for decoding hidden messages from images using steganography. The program reads a PNG image, extracts the encoded message from the pixel values, and writes the decoded message to a text file. It is my solution to the forth Task of the BWINF42 2023.

Project Structure

• St. Egano - Abgabe/
  Main implementation for decoding messages.
• St. Egano - mit DEBUG Tools/
  Version with additional debug output for development.
• bild01.png, bild02.png, ...
  Example images containing hidden messages.
• Ausgabe.text
  Output file with the decoded message.

How It Works

1. The program reads the first pixel of the image.
2. The red value of each pixel is interpreted as an ASCII character and added to the message.
3. The green and blue values determine the coordinates of the next pixel to read.
4. This process repeats until a pixel with green and blue values both equal to 0 is found, marking the end of the message.

Usage

1. Compile the Java files in the src directory.
2. Run the program with the following arguments:
   • Path to the folder containing the image.
   • Filename of the image to decode.

Example:

java -cp bin StEgano "C:\\path\\to\\folder" "bild01.png"

The decoded message will be printed to the console and written to Ausgabe.text in the specified folder.

Requirements

• Java 8 or higher
• PNG images with encoded messages

License

This project is licensed under the MIT License. See LICENSE for further Detail.