This document provides an overview of digital watermarking. It defines digital watermarking as a technique that embeds a low-energy signal or watermark imperceptibly into digital content. The document discusses different types of watermarking including robust, fragile, visible, and invisible watermarking. It also outlines various digital watermarking techniques and applications for copyright protection, content authentication, and metadata tagging. The document concludes that digital watermarking is an effective technique for protecting digital content and preventing illegal copying.

1. DIGITAL WATERMARKING
Shashwat Shriparv
dwivedishashwat@gmail.com

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

3. Introduction
 Advantages of Digital Data
 Copy right problems with digital data
 Encryption & Decryption
 Problems with Encryption & Decryption

4. Conventional Encryption
System

5. Watermark
“ 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.
What is Watermarking?

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

7. Digital Watermarking is originated
from Steganography

8. 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. “
Digital Watermark

9. Digital Watermark (Contn..)
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

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

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

12. The Overall System
The Technology Roars…

13. Importance Of Digital
Watermarking
© Copyright Information
© On-line music industry
© News gathering using digital cameras

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

15. 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

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

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

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

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

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

21. 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

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

23. LSB Watermarking
 Lower order bits of selected pixels in the
image are used to store watermarks
 Replacing lower order bits of each pixel with
higher order bit of different image

24. Color Separation Technique
 Watermark appears only in one of the color
bands
 Used to watermark in still images
 Can be extended to moving images

25. Bit Stream Watermarking
 Used in audio watermarking
 Data is directly inserted into compressed
audio files

26. Word Space Coding, Line Space
Coding &Character Coding
 Used for watermarking in text documents
 In word space coding, the spaces between
words are altered to embed watermark code. In
line space coding the space between the lines
are altered and in character coding some of
the characters are imperceptibly modified (i.e.,
made larger, serifs enhanced, etc).

27. Features of Digital Watermarking
 Imperceptibility
 Robustness
 Security

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

29. Copy Protection
 It limits the access to copyrighted material
and inhibit the copy process

30. Content Authentication
 Robust watermarks are used in this area
Example:-A photographic information that may
be presented as evidence in court. Since digital
images can be easily manipulated, there is a
need to provide proof that an image has not
been altered.

31. Content Authentication

32. Copyright Protection
 One of the main application
 Embedding watermarks in digital
photographs

33. Metadata Tagging
 Watermarks convey object specific information
to users of the object.
 Used to attach patient identification data to
medical images, or to highlight regions of
diagnostic significance.

34. Attacks to Digital
Watermarking
 Stirmark
 Mosaic Attack

35. Stirmark
 It is tool developed to test the robustness of
image marking system
 Stirmark is commonly produced by printers
and scanners
 IBM researchers have recently announced a
technique that defeats the stir mark attack.
 Detects and measures the geometric
distortions in images, and removes the
distortion to restore image geometry

36. Stirmark
Example

37. Mosaic Attack
 Use of a web crawler
 Dividing into sub images with rendition
instructions
 Browser will be rearranging the sub images to
appear as the original
 Sub images will be sufficiently small that no
single image on its own will contain a
recognizable mark.

38. Mosaic Attack
Example

39. Conclusion
 DRM systems and content management are important
for protection of rights of digital multimedia creations
that are distributed on the Internet. Digital
watermarking is an effective technique for embedding
rights information in digital multimedia data.
 Digital watermark technology can be used in consumer
electronic devices like digital still camera, digital video
camera, DVD players, MP3 players, etc., for various
applications like providing controlled access,
preventing illegal replication and watermark
embedding

40. Conclusion (Contd..)
 Digital information can easily be disseminated
and copied via global networks.
 The future of digital watermarking relies on
setting standards and creating applications so
that creators of digital content can easily
implement it.

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

42. Shashwat Shriparv
dwivedishashwat@gmail.com
InfinitySoft