Image Steganography

A Java desktop application that demonstrates image steganography using the Least Significant Bit (LSB) technique.

The application allows users to hide text data inside an image by modifying the least significant bits of the image bytes and later extract the hidden message from the generated image.

This project was developed as the core steganography technique later used in the Secure Data Transmission application.

Features

• Load an image through a Java Swing desktop interface
• Hide text data inside an image using Least Significant Bit (LSB) steganography
• Extract hidden text from a steganographic image
• Store the hidden message length inside the image for accurate extraction
• Read message content from a text file before embedding
• Save the generated steganographic image as a PNG file
• Preview the selected image inside the application
• Reset the application state and process another image/message

How It Works

The application uses the Least Significant Bit (LSB) steganography technique to hide text inside an image.

Encoding

1. The user selects an image.
2. The text message is converted into bytes.
3. The application stores the message length inside the image.
4. Each message bit is written into the least significant bit of the image byte data.
5. The modified image is saved as a PNG file.

Decoding

1. The steganographic image is loaded.
2. The stored message length is extracted first.
3. The application reads the least significant bits from the image bytes.
4. The extracted bits are reconstructed into the original text message.

Because only the least significant bits are modified, the visual difference between the original and generated image is typically difficult to notice.

Tech Stack

Language: Java 8
Desktop UI: Java Swing
Image Processing: BufferedImage, ImageIO
Core Technique: Least Significant Bit (LSB) Steganography
Build / IDE: NetBeans, Ant

Project Structure

Image-Steganography/
├── src/
│   └── image_steganography/
│       ├── ImageSteganography.java
│       ├── Encode.java
│       ├── Decode.java
│       └── ...
│
├── build.xml
├── manifest.mf
└── nbproject/

Running the Application

Prerequisites

Make sure the following are installed:

• Java 8 or later
• NetBeans IDE or another Java IDE with Ant support

1. Clone the Repository

git clone https://github.com/as271996/image-steganography-java.git
cd image-steganography-java

2. Open the Project

Open the project in NetBeans or another Java IDE that supports Ant-based projects.

3. Build the Project

Using Ant:

ant clean
ant

4. Run the Application

Run the main Java class from the IDE.

The application will launch as a Java Swing desktop interface where you can select an image, hide a text message inside it, and later extract the hidden message.

Limitations and Future Improvements

This project demonstrates the core LSB steganography technique and can be further improved with:

• Validation to ensure the selected image has enough capacity for the message
• Support for additional image formats
• Improved error handling for invalid or unsupported files
• Secure password/key-based access for hidden messages
• Encryption of the message before embedding it into the image
• Improved Swing UI and user feedback
• Unit tests for encoding and decoding logic
• Clear separation between UI and steganography logic
• Support for hiding binary files in addition to text

Author

Amit Singh

This project demonstrates the core image-steganography technique used as a foundation for the more complete Secure Data Transmission application.

• GitHub: github.com/as271996
• LinkedIn: linkedin.com/in/amit-singh-sp27