Digital watermarking involves hiding identification information within digital content like images, video and audio. It can be used to authenticate ownership and detect unauthorized copying. There are two main types - visible watermarks which can be seen overlaid on an image, and invisible watermarks which are imperceptible but can be detected algorithmically. Digital watermarking works by imperceptibly altering content to embed a message. It has applications in copyright protection, content management, and tracking of digital media. The embedded data, or watermark, must be invisible, inseparable from the content, and not increase the file size. The Digital Watermarking Alliance promotes standards for watermarking across different media types.

1. Digital
watermarking
By:-jaykrishna Thakkar
Fy Msc-it

2. wHat iS a watermark..?
 Watermarking is an important
mechanism applied to physical objects
like bills, papers, garment labels ,product
packing…
 Physical objects can be watermarked
using special dyes and inks or during
paper
manufacturing.

3. CHaraCteriStiCS of
watermarkS
 The watermark is hidden from view
during normal use, only become visible
by adopting a special viewing process.
– E.g. hold the bill up to light
 The watermark carries information
about the object in which it is hidden.
– E.g. the authenticity of the bill
– E.g. the trademark of the paper
manufacturer

4. HiStory of watermarking
 The term “watermark” was probably
originated from the German term
“wassermarke”. Since watermark is of
no importance in the creation of the
mark, the name is probably given
because the marks resemble the effects
of water on paper.
 Papers are invented in China over a
thousand years ago. However, the first
paper watermark did not appear until
1282, in Italy.

5. HiStory of watermarking
 By the 18th century, watermarks on
paper in Europe and America had been
used as trademarks, to record the
manufactured date, or to indicate the
size of original sheets.
 Watermarks are commonly used on bills
nowadays to avoid counterfeiting

6. wHat iS Digital watermarking?
 Watermarking can also be applied
to digital signals!
image video Audio

7. HiStory of Digital watermarking
 The first watermarking example similar to the
digital methods nowadays appeared in 1954.
The Muzak Corporation filed a patent for
“watermarking” musical Work. An identification
Work was inserted in music by intermittently
applying a narrow notch filter centred at 1KHz.
 About 1995, interest in digital watermarking
began to mushroom.

8. Definitions about Digital
watermarking
 Digital watermarking:
– The practice of imperceptibly alternating a
Work to embed a message about the Work.
 – Related terms
 Work: a specific copy of some electronic signal,
such as a song, a video sequence, or a picture
 Cover Work: the original un-watermarked work,
since it covers (hides) the watermark
 Watermark: the messages being embedded,
indicating some information about the work

9. How it works…

10. types of watermark
 Visible
 A visible translucent
image which is overlaid
on the primary image
 Invisible
 An overlaid image
which cannot be seen,
but which can be
detected
algorithmically

11. Visible watermark
 Logo or seal of the organization which
holds the rights to the primary image,
it allows the primary image to be
viewed, but still marks it clearly as the
property of the owning organization.
 Overlay the watermark in a way which
makes it difficult to remove, if the goal
of indicating property rights is to be
achieved.

12. Visible watermark

13. inVisible watermark
 Embedding level is too small to notice
 Can be retrieved by extraction software
 Applications:
Authentication
Copyrighting
Etc…

14. inVisible watermark

15. ApplicAtions of digitAl
wAtermArking
 Rights management
 Contents management
 Access/copy control
 Authentication

16. feAtures of wAtermArking
 Invisible/Inaudible
 Information is embedded without digital content
degradation, because of the level of embedding
operation is too small for human to notice the
change.
 Inseparable
 The embedded information can survive after some
processing, compression and format transformation.
 Unchanging data file size
 Data size of the media is not changed before and
after embedding operation because information is
embedded directly into the media.

17. technicAl requirements for
wAtermArking
Invisibility
Robustness Capacity

18. digitAl wAtermArking AlliAnce
Represents applications and solutions for:
 Audio and Music Content
 Video, Movies and TV Content
 Digital Imagery
 Identity Documents
 Value Documents

19. digitAl wAtermArking AlliAnce
members

20. digitAl wAtermArking exAmples
 Copyright Communication
 Copy Protection
 Monitoring
 Filtering/Classification
 Authentication/Integrity
 Product Serialization & Tracking
 Asset/Content Management
 Rights Management
 Remote Triggering
 Linking/E-Commerce

21. copyright digitAl
wAtermArk Architecture
Audio/Video Master
Embed Copyright
and Content ID DWM
Content Owner
Provider Index Database Location
(Centralized or Distributed)
User’s PC
Rip Software
Compressed Audio/Video
File (e.g. MP3 file)
User Software
Detect Copyright and Content ID
DWM for Secure and Enhanced
content
Rights & Info Database
Content ID linked to rights, information
and related content
Can be used to address P2P and social network content Identification needs as well
as providing identification of orphan works and access to metadata/networked
information

22. Digital MeDia Serialization &
tracking
 Identifies content owners and rights
while communicating copyright
information
 Awareness of watermarked content by
consumer creates deterrent against
unauthorized copying and distribution
 Provides accurate identification of source
of unauthorized content discovered on
the Internet and/or physical media

23. Protected for
privacy
Recordable Media
Embed
Serial # (2)
Embed
Serial # (1)
Content ID
Retail Content
Content Provider
Track and take
proper action Detect
Serial Number

24. any queStionS…