06-04-2012, 02:11 PM
DIGITAL IMAGE WATERMARKING BASED ON FPGA
project_(2)_0.pdf (Size: 996.88 KB / Downloads: 44)
INTRODUCTION TO WATERMARKING
The last decade has witnessed the rapid development in information technologies and the wide availability of digital consumer device such as digital cameras ,scanners etc .But at the same time this leads to the hacking vulnerability and duplicity of the original information.
HISTORY OF INFORMATION HIDING
The idea of communicating secretly is as old as communicating itself. Steganographic methods made a record debut a few centuries later[ref].
The origin of steganography is considered biological and physiological .A whole branch of steganography ,‖linguistic steganography‖ , consists of linguistic or language forms of hidden writing .A semagram is a secret message that is not in a written form.
CONCEPT OF WATERMARKING
Over the past few years ,several watermarking algorithms have been introduced and their software is accessible ,however recently some hardware realizations are being offered in the literature .Software implementations are easy to use, have upgradability and flexibility but it has limited speed problem and vulnerability to the offline attack.
WATERMARKING EMBEDDING AND DETECTION
The algorithm for the scheme is a kind of digital modulation scheme which uses synchronous detection for decoding of the information .Using LSB modulation method , a gray scale stego image called as modulated signal is produced in which buffer block is transforming 2-D pixel values to 1-D and unbuffer block for transforming 1-D pixel values to 2-D pixel values .
IMPLEMENTATION OF SPINTRONIC LOGIC IN FLIP-FLOPS:
The group of gates thus far implemented are termed as combinational logic circuits .Its basic building block is the logic gate .There are some circuits which have valuable memory characteristics and these are known as sequential logic circuits .Its basic building block is the flip-flop. They are also known as ―latches‖ and ―bistable multivibrators‖.
CONCLUSION
The digital watermarking technique is analyzed using conventional FPGA and spintronics .The comparison has been made on the basis of analysis of results .Logic gates and flip-flops using spintronic devices are characterized by non-volatility ,noise resistance ,robustness ,programmability and low power requirements .The devices and systems built with the help of MTJ ,are expected to have these advantages over those built with the help of conventional silicon-based transistors .