INTRODUCTION

This web page describes my work done in the University of Delaware, Electrical Engineering Department under the supervision of Dr. Charles Boncelet. This undergradaute research project was conducted between 28 June to 28 August 1998 and it was an exchange program between Imperial College, UK and University of Delaware.

WHAT IS THIS PROJECT ALL ABOUT?

The objective of this project is to embed information in JPEG compressed images. For those who wish to know how JPEG works, click here .

First, I had downloaded the source code for JPEG compression from the Portable Video Research Group in Stanford University and studied its implementation. Then, the source code was modified to implement the algorithms to encode a message in an image and also to decode the hidden message.
 

 

WHY THE NEED TO EMBED INFORMATION?

• Steganography.   This refers to the techniques use to hide information in a "wrapper" eg. image or video in a such a way that no one, other than the intended receiver, knows that there is a hidden message in it. The intended receiver then can decode the hidden message.




• Authentication.   By being able to embed a timestamp, your name or a company's logo in an image, it serves as a way of verifying that the image indeed comes from the right party.




• Watermaking.   This technique allows us to leave a digital signature embedded in the image. Such a signature must be robust enough to withstand any tampering so that upon receiving the image, we can verify the originality of the image. The most wide spread use of watermaking is copyright protection.

DEMONSTRATION

Here are 2 pictures (lena at 0.5 bpp) - one has 512 bytes of information embedded in it and the other hasn't. You 've got to guess which one is it? But, don't put your nose too near the monitor!

Hah.....I'll give you one last try. Download this program and use it to decode the hidden message. Remember to read the readme_hide file first.

FUTURE WORKS

Possible areas of extensions:

1) Applying this technique of hiding information to MPEG.

2) Hiding more information in images.

3) Lower data rates without significant degradation in image quality.

This web page is last modified on 28 August 1998. If you have any questions, feel free to email me at l.tay@ic.ac.uk