This is my Lecture #4 about Basics about Watermarking

1. DIGITAL WATERMARKING
LECTURE #4
Presented By
Mrs.Vasanthi Muniasamy

2. Overview
 Introduction
 What is Watermarking?
 What is Digital Watermarking?
 Behind the Technology.
 Importance
 Types of Watermarking.
 Digital Watermarking Techniques.
 Applications

3. Conventional Encryption System

4. Watermark
What is Watermarking?
“Watermarking can be considered as a special
technique of Steganography where one message is
embedded in another and the two messages are
related to each other in some way. “
Example :-
The presence of specific patterns in currency notes
which are visible only when the note is held to light is
a well known example for watermark.

5. Example of a conventional watermark
Courtesy of Blue Spike, Inc.

6. Digital Watermarking is originated from
Steganography

7. Digital Watermark
What is Digital Watermarking?
“Digital watermarking is similar to watermarking
physical objects, except that the watermarking technique
is used for digital content instead of physical objects. “

8. Digital Watermark
 In digital watermarking a low-energy signal is
imperceptibly embedded in another signal. The
low-energy signal is called watermark.
 The main signal in which the watermark is
embedded is referred to as cover signal since it
covers the watermark.
 An entity called watermark key used for
embedding and detecting watermark signal
 Watermark key is private

9. Behind The Technology
Sending Side …
Watermark Embedding process
 Water mark
 Original Image
 Key
 Water marked image

10. Behind The Technology
Receiving Side …
Watermark retrieval process
 Water marked image
 Key
 Confidential message

11. The Overall System
The Technology Roars…

12. Importance Of Digital Watermarking
© Copyright Information
© On-linemusic industry
© News gathering using digital cameras

13. Types of Digital Watermarking
 Robust & Fragile Watermarking
 Visible & Invisible Watermarking
 Public & Private Watermarking
 Asymmetric & Symmetric Watermarking
 Steganograhic & Non-Steganographic
watermarking

14. Robust & Fragile
Watermarking
 Robust Watermarking:-Modification of
watermarked content will not affect watermark
 Fragile Watermarking:-Watermark get
destroyed when watermarked content is
modified or tampered with

15. Visible & Invisible
Watermarking
 On Visible watermarking, contents are visible

16. Visible & Invisible
Watermarking (Contn..)
 Invisible watermarking are not viewed on
just looking

17. Public & Private
Watermarking
• Public Watermarking
Users of content are authorized to detect
watermark
• Private Watermarking
Users not authorized to detect watermark

18. Asymmetric & Symmetric
watermarking
 In Asymmetric watermarking different keys
used for embedding and detecting watermark

19. Asymmetric & Symmetric
watermarking (Contn..)
 In symmetric watermarking same keys are
used for embedding and detecting watermarks

20. Steganographic & Non-
Steganographic
Watermarking
 Steganographic Watermarking
User unaware of the presence of a watermark
eg:-Used in finger printing applications
 Non-Steganographic WM:-
User aware of the presence of a watermark.
e.g.:-User to detect piracy

21. Digital Watermarking
Techniques
 LSB Watermarking
 Color Separation Technique
 Bit Stream Watermarking
 Word Space Coding, Line Space Coding
&Character Coding

22. Applications of Digital
Watermarking.
 Copy Protection
 Content Authentication
 Copyright Protection
 Metadata Tagging

23. References
 www.watermarkingworld.org
 www.digital-watermark.com