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Presented by:
Abhipsa Dash
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What is watermark
A watermark is a recognizable image or pattern in paper/background that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), caused by thickness or density variations in the paper/background.
What is digital watermarking?
The process of digitally inserting a watermark into a multimedia object in such a way that the watermark can be detected or extracted later easily to make an impression about the object and it’s owner is called digital watermarking.
Encoding of watermarking to an object
Let’s denote an image by I, a signature by S and the watermarked image by I’ . E is an encoder function, taking the image I and signature S, and generating a new image called watermarked image (I’).
Mathematically, E(I,S)=I’
Following figure illustrates the encoding process.
Decoding of watermark
A function D takes an image ‘J’ whose ownership is to be determined and recovers a signature S’ from the image. In this process an additional image ‘I’ can also be included which is often the original and un-watermarked version of ‘J’ .
Mathematically, D(J , I )= S’
The extracted signature S’ will then be compared with the owner signature sequence by a comparator function C and a binary output decision generated. It is 1 if there is match and 0 otherwise .
Types of watermarking
1. Image watermarking
a ) Visible watermarking
b ) Invisible watermarking
2.Video watermarking
3. Audio watermarking
4. Text watermarking
Image watermarking
According to human perception image watermarking is of two types
1. Visible watermarking
2. 2. Invisible watermarking
1. VISIBLE WATERMARK:
A visible watermark is a semi-transparent text or image overlaid on the original image. This watermark appears visible to a casual viewer on a careful inspection. Visible watermarks are more robust against image transformation.
2. Invisible Watermarking:
An “invisible watermark” is an embedded image which cannot be perceived with human eye. Only electronic devices can extract the hidden information to identify the copyright owner. It is used to mark a specialized digital content (text, images or even audio) to prove its authenticity.
2. VIDEO WATERMARKING:
The process of watermarking the sequence of video frames is called video
watermarking. To watermark a video file we have to watermark each
frame of the video file.
3. AUDIO WATERMARKING:
The process of embedding information into audio can be termed as audio
watermarking. In case of audio watermarking the time and frequency
property of human ear is used to hide the watermark and make it
inaudible.
4. TEXT WATERMARKING:
The process of embedding/hiding data in text can be termed
as text watermarking. At the time of printout some of the information is
hidden.
Types of possible attacks
THERE ARE MAINLY FOUR TYPES OF POSSIBLE ATTACKS:
• Active Attacks – Hacker tries to remove the watermark or make it undetectable.
• Passive Attacks – Hacker tries to determine whether there is a watermark and identify it. However, no damage or removal is done.
• Forgery Attacks – Hacker tries to embed a valid watermark of their own rather than remove one.
• Decorative Attacks – Hacker applies some distorted transformation uniformly over the object in order to degrade the watermark so that it becomes undetectable/unreadable.
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plz upload the ppt of Digital Watermarking...and also report...
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PRESENTED BY:
Parag Agarwal
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Digital Watermarking
[attachment=12891]
Information Hiding
Information Hiding…..started with
Steganography (art of hidden writing):
The art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message. The existence of information is secret.
Steganography (dates back to 440 BC)
Histaeus used his slaves (information tattooed on a slave’s shaved head )
Microchip - Application
Germans used Microchips in World War II
What is a watermark ?
What is a watermark ? A distinguishing mark impressed on paper during manufacture; visible when paper is held up to the light (e.g. $ Bill)
What is a watermark ?
Digital Watermarking: Application of Information hiding (Hiding Watermarks in digital Media, such as images)
Digital Watermarking can be ?
- Perceptible (e.g. author information in .doc)
- Imperceptible (e.g. author information in images)
Visibility is application dependent
Invisible watermarks are preferred ?
Applications
Applications
Tamper proofing: To find out if data was tampered.
Applications
Quality Assessment: Degradation of Visual Quality
Comparison
Watermarking Vs Cryptography
Watermark D Hide information in D
Encrypt D Change form of D
Watermarking Process
Data (D), Watermark (W), Stego Key (K), Watermarked Data (Dw)
Embed (D, W, K) = Dw
Extract (Dw) = W’ and compare with W
(e.g. find the linear correlation and compare it to a threshold)
Q. How do we make this system secure ?
A. K is secret (Use cryptography to make information hidden more secure)
Watermarking Process Example – Embedding (Dw = D + W)
Matrix representation (12 blocks – 3 x 4 matrix)
(Algorithm Used: Random number generator RNG), Seed for RNG = K, D = Matrix representation, W = Author’s name
Watermarking Process Example – Extraction
The Watermark can be identified by generating the random numbers using the seed K
Data Domain Categorization
Spatial Watermarking
Direct usage of data to embed and extract Watermark
e.g. voltage values for audio data
Transform Based Watermarking
Conversion of data to another format to embed and extract.
e.g. Conversion to polar co-ordinate systems of 3D models, makes it robust against scaling
Extraction Categorization
Informed (Private)
Extract using {D, K, W}
Semi - Blind (Semi-Private)
Extract using {K, W}
Blind (Public)
Extract using {K}
- Blind (requires less information storage)
- Informed techniques are more robust to tampering
Robustness Categorization
Fragile (for tamper proofing e.g. losing watermark implies tampering)
Semi-Fragile (robust against user level operations, e.g. image compression)
Robust (against adversary based attack, e.g. noise addition to images)
Categorization of Watermark
Eg1. Robust Private Spatial Watermarks
Eg2. Blind Fragile DCT based Watermarks
Eg3. Blind Semi-fragile Spatial Watermarks
Watermarking Example
Application: Copyright Protection
Design Requirements:
- Imperceptibility
- Capacity
- Robustness
- Security
Imperceptibility
Robustness
Adversaries can attack the data set and remove the watermark.
Attacks are generally data dependent
e.g. Compression that adds noise can be used as an attack to remove the watermark. Different data types can have different compression schemes.
Robustness
Value Change Attacks
- Noise addition e.g. lossy compression
- Uniform Affine Transformation e.g. 3D
model being rotated in 3D space OR
image being scaled
If encoding of watermarks are data value dependent
Watermark is lost Extraction process fails
Robustness
Sample loss Attacks
- Cropping e.g. Cropping in images
- Smoothing e.g. smoothing of audio
signals e.g. Change in Sample rates
in audio data change in sampling rat
results in loss of samples
If watermarks are encoded in parts of data set which are
lost Watermark is lost Extraction process fails
Robustness
Reorder Attack
- Reversal of sequence of data values e.g. reverse filter in audio signal reverses the order of data values in time
Capacity
Multiple Watermarks can be supported.
More capacity implies more robustness since watermarks can be replicated.
Spatial Methods are have higher capacity than transform techniques ?
Security
In case the key used during watermark is lost anyone can read the watermark and remove it.
In case the watermark is public, it can be encoded and copyright information is lost.
Watermarking Algorithm Design Requirements
As much information (watermarks) as possible
Capacity
Only be accessible by authorized parties
Security
Resistance against hostile/user dependent changes
Robustness
Invisibility
Imperceptibility
Tamper proofing
Robustness against user related operations – compression, format conversion
Accuracy of Detection – Only changes in meaning should be detected
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27-04-2011, 02:33 PM
please send me the full seminar report and presentation
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plz check all report information did u get..
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05-05-2011, 09:29 AM
:
Please send me the report on Digital Watermarking
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[attachment=13625]
Objective:-
The purpose of the project is
à To add the watermarks to the image inside to hide the data from the unauthorized persons.
à To Provide copy right Protection for the Documents.
Introduction :-
Watermarking can be defined as an act of embedding a message i.e. a text or an image into a existing work .
(or)
Watermarking can also be defined as an invisible signature.
More recently, different watermarking techniques and strategies have been proposed in order to solve a number of problems, ranging from the detection of content manipulations, to information hiding (steganography), to document usage tracing.
Why Watermarking ?
Security of multi media communications is regarded by both academy and industrial research as one of the most important and urgent problems of last decades.
Watermarking is the art of imperceptibly embedding a message into a work. More recently, different watermarking techniques and strategies have been proposed in order to solve a number of problems, ranging from the detection of content manipulations, to information hiding (steganography), to document usage tracing.
The possibility of adding several watermarks to the same image would enable many interesting applications such as multimedia document tracing, data usage monitoring, multiple property management.
Existing System :-
In the existing system we used single watermarking concept. In this concept overwriting applied only one time. So, it has some low security. In the Traditional (and Conventional) method of Watermarking, the Watermark is made during the paper manufacturing process. Once the water marking has been applied to the paper then we cannot change it or overwrite it, which makes insecure in the water marking technique.
Existing System Disadvantages :-
Minimum Order Quantity is HUGE (Typically Larger Than 30 Tons of Paper)
Paper Mill has to recover the cost of the Dandy Roll, which is very expensive to make
INCONSISTENT Positioning of the Watermark across all the Sheets
Proposed System :-
Here we are providing multiple watermarking concepts, such as the sample image overwrite more than one time on the original image. Its robustness against standard image degradation operations has been extensively tested and its security under projection attack has also been proven even though the envisaged application refers to a collaborative environment, in which malicious attacks are not a critical aspect.
Proposed System Advantages :-
• In this scheme we use multiple watermarking.
• We can implement text based, image based, passcode based.
• We can watermark even after manufacturing of paper.
• The encryption is done by symmetric key cryptographic algorithm that is fast and inexpensive.
Modules :-
This project contains four modules. They are:
Preprocessing
Resolution Hiding
Watermarking
Security providing
Briefly about Modules :-
Preprocessing :-
Preprocessing is nothing but the color enhancement where the quality of the picture is increased. The quality can be varied by using the parameters like contrast, Brightness/Gamma, Saturation, etc
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i want matlab code for digital watermarking using dct and wavelet
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hi... iam jaideep.. doin b.tech in govt. engg colg calicut.. i would like to do digital water marking as my seminar on dis 7th semester.... can u pls give notes about dis topic...
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i want full report on digital water marking
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this is very beautiful site for seminar finder
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HI... very good work, but, please send or post the rar password for the file...
thanks to u...
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please send the full report and ppt for digital watermarking as soon as possible....
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Watermark = Water (Invisible) + Mark
Media Copyright Protection
- Develop of e-commerce
- Ownership
Two Different Viewpoints
- Watermark-as-signal
- Watermark-as-information
Why Watermarking?
Secure Distribution of Digital Contents
- Unlimited copies of original contents
- Instant distribution over internet
- Quick download of compressed streams
Content Protection
- Authentication
- Encryption/Decryption
- Watermarking
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hai,
i am very happy to join.i want some model project paper.please send to my mail
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hiiiiiiiiiiiiii send me digital watermarking ppt.....
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im glad to take this report. 
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Hi i want reprt on digital voltmeter
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i need adv of this.and i need the advantage of digital watermarking that is used in the robust video data hiding
