Date post: | 27-Oct-2014 |
Category: |
Documents |
Upload: | manjesh-kumar |
View: | 65 times |
Download: | 3 times |
VIDEO WATERMARKING
Presented by:-
MANJESH KUMAR (12100027)
Guided by:-
Dr. David Peter S.
CONTENTS • Introduction • Need for video watermarking • Video watermarking terminologies • Types for video watermarking • Desired properties • Application of watermarking Structure of a Typical Video Watermarking
System
• An algorithm of video watermarking • Attack on watermark • Conclusion • References
INTRODUCTION
Definition: A digital watermark is a digital signal or
pattern inserted into a digital document such as text, graphics or multimedia, and carries information unique to the copyright owner.
Video watermarking is an extension of this concept.
Need for video watermarking
Protect copyright of a data.
Video Watermarking can help
◦ Prove ownership
◦ Identify a misappropriating person
◦ Trace the video dissemination
Broadcast Monitoring
Video watermarking introduces some issues not present in image watermarking
Frame averaging, frame dropping, frame swapping …
Video watermarking terminologies
• Digital Video
• Payload
• Perceptibility
• Robustness
• Security
TYPES of Video Watermarking
Two types :-
1. Visible
2. Invisible
Visible watermarks it’s use : -
1. To discourage unauthorized usage. 2. As an advertisement
Visible watermarking algorithm
Least Significant Beat (LSB)
EXAMPLE OF VISIBLE VIDEO WATERMARKING
Invisible watermarks
Three types of Invisible watermark :
1. Robust Watermarks
2. Fragile Watermarks
3. Public and Private Watermark
No degradation in the aesthetic quality of the data.
Invisible Robust Video Watermarking Techniques Spatial Domain Method
Frequency Domain Method
DESIRED PROPERTIES
Robust
Video watermarking ( frame averaging, frame dropping, frame swapping... )
Recoverable from a document
Removable by authorized users
Low error probability
Provide the original information embedded reliably
Capacity
Invisible
APPLICATION OF WATERMARKING
• Owner Identification
• Proof of Ownership
• Transaction Tracking
• Content Authentication
• Broadcast Monitoring
• Device Control
• Automatic monitoring of copyrighted material on
the Web
A Generic approach to watermarking digital data
There are 3 main processes involved in watermarking —
1. Insertion of a watermark
2. Detection of a watermark
3. Removal of a watermark
Inserting a watermark
It consists of :-
A watermark insertion unit that uses:-
a. Original video
b. Watermark
c. A user key
to obtain the watermarked video.
watermark insertion unit
The user key , input video and the watermark are passed through a watermark insertion unit.
This results in a watermarked video.
Watermark Extraction Unit
Two phases:-
1. Locating the watermark
2. Recovering the watermark information.
Watermark Detection Unit
Consists of :-
a. An extraction unit to first extract the watermark.
b. Compare it with the original watermark inserted.
c. The output is Yes or No depending on whether the watermark is present.
A watermarking algorithm — The LSB technique
Let’s consider still images.
Each pixel of the color image has three components — red, green and blue.
3 bytes for each pixel.
Each color has 1 byte, or 8 bits.
Each bits has it’s own value 2pow(n) .
The LSB technique…….
A pixel that is bright purple in color can be shown as
X0 = {R=255, G=0, B=255}
Another pixel:
X1 = {R=255, G=0, B=254}
The Algorithm
1.A raw bitmap image „A’ will be selected from the set of standard test images. Let
this be the base image on which the watermark will be added.
2. A raw bitmap image „B‟ will be selected from the set of standard test images. This
will be the watermark image which will be added to the base image.
3. The most significant bit henceforth will be mentioned as MSB, of watermark image
„B‟ will be read and these will be written on the least significant bit, henceforth will
be mentioned as LSB, of base image „A‟.
4. Thus, „A’ will be watermarked with ‘B’ resulting in a combined image ‘C‟.
5. ‘C’ therefore will now contain an image ‘A’ which has its LSBs replaced with
the MSBs of ‘B‟.
6. This technique is used to add an invisible and visible watermark.
Distortions and attacks
Additive Noise.
Cropping.
Compression.
Statistical Averaging.
Multiple Watermarking.
Mosaic Attack
An Algorithm of Invisible Video Watermarking
Raw video watermarking
◦ DWT (Discrete wavelet transform)
◦ DCT ( Discrete cosine transform)
◦ DFT ( Discrete frequency transform)
Discrete Wavelet Transform
Normalized to 256 X 256 pixel size
Perform DWT for each frame
Advantage of DWT Prevent from frame dropping
Prevent from adding noise / another video
Mark with m1
Mark with m3
Mark with m0
Mark with m6
Scene change occur
Watermark Preprocess Safe from frame averaging Hard to reconstruct the watermark
85
64 0
1
2
4
5
6
7 3
Crop
Bit
Decomposition
8 bit-
planes
17
0
25
6
0
1
2
4
5
6
7 3
8 bit-
planes
17
0
25
6
0
1
2
4
5
6
7 3 Total 8 images
is obtained
m0
m7
Place the bit-
planes side by
side
Watermark Embedding
C[i] = C[i] + 1 , if W[j] = 1
C[i] = C[i] , otherwise
LL, HH is not watermark
HL1
LH1 HH1
HL2
HH2 LH2
LL
LH
LH3 HH3
HL3 HL
HH
170
256
0
1
2
4
5
6
7 3
Watermark mi
Watermark Detection
1. Video Frame
256 X 256 3. DWT
DWT result frames
Original video frames 4. Compare
2. Detect the scene change
5. Averaging the watermark
get from different frames
Watermark mi
170
256 m0
m1
m2
m4
m5
m6
m7 m3
7. Get different part of W
from different scene and
reconstruct the large image
170
256 0 1 2
4 5 6 7 3
6. Combine 8 bit-planes 85 64
8. Correlate and verify
Extracted Original
E O
Mark with m1
Mark with m3
Mark with m0
Mark with m6
Scene change occur
Future Direction
Implement and use do experiment on the scheme
Identifiable from very short segment of video
Change to blind watermarking scheme
ATTACK ON WATERMARK
Compression
Rescaling
Cropping
Multiple watermarks
• Frame averaging
• Frame dropping
• Frame swapping
• Statistical analysis
CONCLUSION
Need due to Copyright protection
Different from image watermarking
Brief review of current technologies
DWT-based Video Watermarking Scheme with
Scramble Watermark
Future Direction
Inadequate for general use
Different tools offering this watermarking
Set to grow
REFERENCES
F. Hartung and M. Kutter, “Multimedia watermarking techniques”,Proceedings of the
IEEE, vol. 87, no. 7 , July1999.
I. Cox, J. Kilian, T. Leighton, and T. Shamoon, “Secure spread spectrum watermarking
for images, audio and video,” in Proc. IEEE Int. Conf. Image Processing (ICIP 96),
Lausanne, Switzerland, Sept. 1996.
Yeo and M.M. Yeung, “Analysis and synthesis for new digital video applications,” icip,
International Conference on Image Processing (ICIP'97),vol. 1, pp.1,1997.
Ingemar J. Cox, Matthew L. Miller, Jeffrey A. Bloom “Digital Watermarking” Morgan
Kaufmann Publishers ISBN: 1-55860-714-5
http://www-ee.uta.edu/dip/Courses/EE5355/jpeg.html
“Privacy principles for digital watermarking”, Ver. 1.0, May 2008. Website:
https://www.cdt.org/