technical seminar presentation-2004 presented by : ashok kumar sahoo (ei200118123) national...

Technical Seminar Presentation-2004

Presented by : ASHOK KUMAR SAHOO (EI200118123)

NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

Presented By

Ashok Kumar Sahoo Roll # EI 200118123

DIGITAL WATERMARKIG IN SPATIAL DOMAIN

Under the guidance of

Mr. S. K. Meher

1



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

OUTLINE

• Introduction

• Methods

• New Image Watermarking Algorithm

• Experimental Results

• Future Direction

• Conclusion

2



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

INTRODUCTION• Watermarking is a concept of

embedding a special pattern, watermark, into a document

• Watermarking is a key process for the protection of copyright ownership of electronic data

Watermarking Algorithm

WatermarkedImage Ì

Host-Image I

Watermark W

Secret / public key K

3



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

INTRODUCTION

• An existing scheme for still image watermarking in spatial domain is studied.

• The features of the algorithm are: – The watermark to be embedded is a visually

meaningful binary image;– More resistant to any attack;– retrieval of embedded watermark is easy;– the watermark is perceptually invisible;

4



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

WHY DIGITAL WATERMARKING

• Cryptography ensures confidentiality, authenticity, and integrity

• It cannot help after decryption • Digital Watermarking can help

– Prove ownership– Identify a misappropriating person– Trace the marked document’s

dissemination through the network

5



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

HOW IT WORKS

6



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

TECHNICAL REQUIRMENTS

Robustness

Capacity

Invisibility

7



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

• Digital watermarking techniques can be divided into two broad categories:

• 1.Spatial domain methods .

• 2 Frequency domain methods.

METHODS FOR DIGITAL WATERMARKING

8



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

SPATIAL DOMAIN METHODS

• The term spatial domain refers to the aggregate of pixels composing an image. Spatial domain methods are procedures that operate directly on these pixels. Spatial Domain processes will be denoted by the expression ,

g(x,y)= T[f(x,y)]

9



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

ATTACKS ON WATERMAKING

• Compression

• Rescaling

• Processing operation

• Cropping

• Multiple watermarks

10



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

THE PROPOSED MODEL

11



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

EMBEDDING WATERMARK

12



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

WATERMARK DETECTION

• b=1 if Snew >So,

• b=0 Otherwise.

13



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

EXPERIMENT RESULT

• The proposed algorithm was implemented using Matlab where the watermark is extracted after compression attack.

• Results

14



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

EVALUATION

• A simple watermarking scheme

• Invisibility

• Resist to lossy compression

• Watermark is invisible even though the picture in binary format.

15



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

APPLICATIONS

• Copyright defense

• Three types of watermark i) Private-key

ii) Detection-key

iii) Public-key

• Trace the route of the certain files during distribution

16



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

FUTURE DIRECTION

• Increase robustness against lossy compression

• Use better quad tree decomposition coding

• Change the way to insert key. • Encode the watermark before

embedding.• Extend the watermark techniques to

wireless environment

17



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

CONCLUSION

• Video Watermarking is needed since copyright protection is essential

• Watermarking in spatial domain is different from frequency domain.

• Spatial domain watermarking model is proposed and implemented

• Watermark is embedded in MSB to increase the efficiency

18



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

THANK YOU!!!!

19



NA

TIO

NA

L I

NS

TIT

UT

E O

F S

CIE

NC

E &

TE

CH

NO

LO

GY

technical seminar presentation-2004 presented by : ashok kumar sahoo (ei200118123) national...

Documents