Digital Watermarking for Videos

8/2/2019 Digital Watermarking for Videos

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Mohit Singh (08BCE172)

Puneet Singla (08BCE229)Rupesh Soni (08BCE274)


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Watermarking can be used in a wide variety of

applications. In general, if it is useful to associate some

additional information with a Work, this metadata can

be embedded as a watermark.

1. Broadcast Monitoring

2. Owner Identification

3. Proof of Ownership

4. Transaction Tracking5. Content Authentication

6. Copy Control


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Digital watermarking is a technique which allows an

individual to add hidden copyright notices or other

verification messages to digital audio, video, or image

signals and documents.

Such hidden message is a group of bits describing

information pertaining to the signal or to the author of

the signal (name, place, etc.).


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A watermark can be classified into two sub-types:

visible and invisible:

Visiblewatermarks change the signal altogether such

that the watermarked signal is totally different from the

actual signal, e.g., adding an image as a watermark to

another image.


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Invisiblewatermarks do not change the signal

to a perceptually great extent, i.e., there are

only minor variations in the output signal.

An example of an invisible watermark is when

some bits are added to an image modifying

only its least significant bits.


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Fidelity

Robustness

BlindD

etection Capacity

Statistical Imperceptibility

Speed


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Subtractive Attack

Distortive Attack

Additive Attack

Filtering Attack

Cropping Attack

Compression

Rotation & Scaling

Statistical Averaging


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Frame Dropping

Frame Averaging

Frame Swapping

Frame Insertion

Statistical Analysis


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1. Spatial Domain Watermarking: The watermark is applied in the pixel or coordinate domain.

No transforms are applied to the host signal during watermark

embedding.

The watermark is derived from the message data via spread spectrum

modulation.

Combination with the host signal is based on simple operations, in the

pixel domain.

The watermark can be detected by correlating the expected pattern

with the received signal.

Conceptually simple and have very low computational complexities.


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I. LeastSignificant Bit:The most straight-forward method of

watermark embedding, would be to embed the watermark intothe least-significant bits of the cover object. Given the

extraordinarily high channel capacity of using the entire cover

for transmission in this method, a smaller object may be

embedded multiple times.

II. Corelation Based Technique:Another technique for watermark

embedding is to exploit the correlation properties of additive

pseudo-random noise patterns as applied to an image.


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2. Frequency Domain Watermarking

I. Discrete Cosine Transform:

x The DCT allows an image to be broken up into different frequency bands,

making it much easier to embed watermarking information into the middle

frequency bands of an image.

x The middle frequency bands are chosen such that they have minimize they

avoid the most visual important parts of the image (low frequencies)

without over-exposing themselves to removal through compression and

noise attacks (high frequencies).

II. Discrete WaveletTransform:

x The DWT (DiscreteWavelet Transform) separates an image into a lower

resolution approximation image (LL) as well as horizontal (HL), vertical (LH)

and diagonal (HH) detail components.


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III. Discrete Fourier Transform:

x This approach first extracts the brightness of the to-be-marked

frame, computing its full-frame DFT and then taking the

magnitude of the coefficients.

x The watermark is composed of two alphanumerical strings.The

DFT coefficient is altered, then IDFT.

x Decide to watermark one or more frames in GOP, a trade-off

between time spent for marking and the degree of robustness

needed for the sequence can be achieve.


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Video watermarking introduces some issues not

present in image watermarking.

Due to large amounts of data and inherent redundancy

between frames, video signals are highly susceptible to

pirate attacks, including frame averaging, frame

dropping, frame swapping, statistical analysis, etc.

However, the existing algorithms do not solve these

problems effectively.


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The new watermarking scheme we propose is based on

scene change analysis.

Our scheme embeds different parts of a single watermark

into different scenes of a video under the wavelet domain.

Our scheme employs independent watermarks for

successive but different scenes.

It allows blind retrieval of embedded watermark which does

not need the original video.

The watermark is perceptually invisible.


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Applying independent watermarks to each frame also

presents a problem if regions in each video frame remain

little or no motion frame after frame.

These motionless regions may be statistically compared or

averaged to remove the independent watermarks.

Consequently, we use an identical watermark within each

motionless scene.

With these mechanisms, the proposed method is robust

against the attacks of frame dropping, averaging, swapping,

and statistical analysis.


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Embedding


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Extraction


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2. Watermark Embedding:

o The watermark is then embedded to the video

frames by changing position of some DWT

coefficients.

o The higher frequency coefficients of the watermark

are embedded to higher frequency parts of the

video frame, and only the middle frequency wavelet

coefficient of the frame (middle frequency sub-

band) is watermarked


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3. Watermark Extracting:

oScene changes are detected from the tested

video.oEach video frame is transformed to the wavelet

domain.Then the watermark is extracted

oThe retrieval of the embedded watermark does

not need the original image


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Level-1 DWT

Decomposition


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Level-2 DWT

Decomposition


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1. M. Barni, F. Bartolini, R. Caldelli, A. De Rosa, and A. Piva, A Robust Watermarking

Approach for RawVideo, Proceedings 10th International PacketVideoWorkshop

PV2000, Cagliari, Italy, May 1-2 2000

2. P.W. Chan and M. Lyu, ADWT-based Digital Video Watermarking Scheme with

Error Correcting Code, Proceedings Fifth International Conference on Informationand Communications Security (ICICS2003), Lecture Notes in Computer Science,

Springer, Vol. 2836, pp. 202-213, Huhehaote City, Inner-Mongolia, China, Oct. 10-13,

2003.

3. P.W. Chan, M.R. Lyu, R. Chin, Copyright Protection on the Web: A Hybrid Digital

Video

Watermarking Scheme, Poster Proceedings 13th International World Wide

Web Conference (WWW2004), pp. 354-355,New York,May 17- 22, 2004.


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4. J. Lee and S. Jung, A survey of watermarking techniques applied

to multimedia, Proceedings 2001 IEEE International Symposium

on Industrial Electronics (ISIE2001),Vol. 1, pp. 272-277, 2001.

5.Wikipedia,http://www.wikipedia.org

6.F.Duan, I. King, L. Xu, and L. Chan, Intra-block maxmin algorithm

for embedding robust digital watermark into images, In Horace

H.S. Ip and ArnoldW.M. Smeulders, editors,Proceedings of the

IAPR International Workshop on Multimedia Information Analysis and

Retrieval, MINAR 98, Lecture Notes in Computer Science,Vol. 1464,

pp. 255-264, Berlin Heidelberg, Germany, 1998. Springer- Verlag

Digital Watermarking for Videos

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