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Full animated slides, produced to give the introductory+advance knowledge about watermaking techniques.
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Digital Water Marking
By
Sheikh Qaisar Ayub
Advanced Topics in Image Processing
Qaisar Ayub & Sulma Rashid
Watermark
Observe image It is intellectual property
Some one may spend a lot of time And thinking to compose this image
The image has been extended by any other person now he is owner of image
How to protect image ?Problem
Solution Watermark
What ?The term watermark is derived from the German term “Wessmark”
Basic Idea
The basic idea of watermark is to embed some information in digital
images so that it can not be miss used or owned by others
Watermarked imageImage without watermark
Watermark
Visible watermark- The visible watermark consist of visible message of company logo
indicating the ownership of image.
Watermark
Visible watermarkThe implementation of visible watermarks can be applied in following areas
1. Word Document
Types of Digital Watermark
Visible watermarkThe implementation of visible watermarks can be applied in following areas
2. On Images
Types of Digital Watermark
Visible watermark2. Multimedia Files
Types of Digital Watermark
Click on image to Play
Invisible watermark- The watermark will not appear on the image and its existence can be determined
using appropriate watermark extraction or detection algorithm.
ExplanationAn invisible watermark technique consist of an encoding process and a decoding process.
Types of Digital Watermark
Invisible watermark
Types of Digital Watermark
How to implement ?
Step -1Select randomly the area of image to obtain its pixel values
A=
Invisible watermark
Types of Digital Watermark
How to implement ?
Step -2Convert into its binary values
B=
A=
Invisible watermark
Types of Digital Watermark
How to implement ?
Step -3Form a watermarking key
Watermark Key
A=
C=
B=
Invisible watermark
Types of Digital Watermark
How to implement ?
Step -4The OR Operation is used
B=
D= B + C
0110010100000011
01101000
0110010000000001
01100101
0110011000000010
01101000
0110011100000000
01100111
Summery
1. Select randomly area of image and get its pixel values
2. Obtain its digital values
3. Convert to binary
4. Get a key matrix consisting binary values
5. Embed watermark using D:= B OR C
Types of Digital Watermark
A=
B=
C=
Types of Digital Watermark
01100101
00000011
01101000
Encoder Key
Data
ENCODING Algorithm
NoteWatermark will not effect the composition of image
We have add a invisible water mark in the image
The process of embedding the invisible watermark in image is called ENCODING
Achievement
Invisible watermarkWe have embed the watermark in image
Can this image be owned by others?
Types of Digital Watermark
The Answer is yes
What is the function of watermark ?
Example 1. Mr. Ali Compose a image
2. He then embed a watermark in it
3. Later on Mr.Jamil access this image and modify it and clam its ownership
4. Mr.Ali can detect his image by extracting the embedded watermark and can reclaim the ownership
Invisible watermark Decoding- The process of extracting the embedded watermark from image is called Decoding.
- The image can only be decoded by using the decoded algrothem with the key which was used for encoding.
Types of Digital Watermark
01101000
Extract the encoded data from image
Input to Decoding Algorithm
Detect watermark Algorithm
01100101
Example
Extract Watermark Algorithm
Watermark detected by the Algorithm and hence intellectual property can be saved.
Encoding & Decoding
01100101
00000011
01101000
Encoder Key
Data
ENCODING Algorithm
Extract Watermark Algorithm
DECODING Algorithm
Communication Media
01101000
Mathematically Encoding
X’ = EK (X,W)HenceX = Original ImageW= watermark information being embeddedK= user insertion keyE= watermark insertion functionX’ = Watermarked Image
Mathematically Decoding
W = DK’ (X’)HenceX’ = Watermarked imageK’= extraction keyD= watermark extraction functionW= Extracted watermarked information
We have understand the process of extracting the watermarked key from image
Encoding and Decoding Mathematically
Achievement
Application of watermark
1. Ownership Declaration
Application of watermarkFinger Print IS File save ?
Application of watermarkFinger Print
Data Center-01
Data Center-02
Data Center-03
Network
Application of watermarkFinger Print
A invalid copy is found at any location
Extract the embedded figure print From file
A figure print is unique value form each data center
Can identify the data center
Application of watermark
Embed the number of copies to be allowed for copying embed in the hardware
4
4 3 2 1
Copy not allowed
Click on image to Play
Application of watermarkFraud Detection
Data Center-01
Data Center-02
Data Center-03
Network
5. ID Card & Security
Application of watermark
Muhammad IshfaqueKarim Ahmad
Observe ID card
WHAT IS THE PROBLEM ?
5. ID Card & Security
Application of watermark
Muhammad Ishfaque
Muhammad Ishfaque
Extract name using watermarked algorithm
Muhammad Ishfaque
Compare the to validate ID CARD.
M Jamil
M.jamil
M.jamil
Muhammad Ishfaque
We have understand the application of water mark
Achievement
Robustness
The ability of watermark to provide the resistance against the modification of image is
called robustness
Modification
Original Image
Properties of Watermark
Resize Rotation & Compression
No perceptibility
“ When we embed a invisible watermark by changing it bits it will not effect Human visual
system”
Modification
Original Image
Properties of Watermark
Watermarked image
Non Detectable
Design a watermark that is not detectable by the outer attacks
Complexicity
The amount of time required to encode & decode a image is called complexicity
Properties of Watermark
We have understand the properties of watermarks
Achievement
Methods of Water MarkingWater Marking in Spatial domain
The values of the image pixels are directly modified based on the
water mark that has to be embedded.
Advantage
- Simple
- Less computational required
Drawback
- No security against modification
Water marking in frequency domainA distributed sequence inserted into the perceptually most significant
frequency components.
Image: 11001010 00110101 00011010 00000000...
Watermark: 01 01 10 11...
Watermarked Image:11001011 00110010 00011100 00000011...
Methods of Water Marking
Thanks