ASEMINAR
ONDIGITAL WATERMARKING
PRESENTED BY:VIDHI AGARWAL
CS FINAL YR.CSE/1754
TABLE OF CONTENTS
Introduction to DW Information Hiding Process of DW Watermarking issues Types of DW Watermark attack Application of DW Limitations of DW Conclusion
INTRODUCTION TO DW
Digital watermarking is the process of embedding information into a digital signal.
The purpose of digital watermarking is to provide copyright protection.
INFORMATION HIDING
The process of secretly embedding inside a data source without changing its perceptual quality.
DW and steganography are the implementations of information hiding.
CONTINUED…..
Extractionfunction
M(L)
Channel
Retrieved information
M(L)
Information to embed
Embedding
function
^
Key
Original data
PROCESS OF DW
Fig. Watermark embedding
CONTINUED….
Fig. Watermark detection
DETECTIONS OF WATERMARK
Fig . Using digital watermarks for integrity verification: the protected image is the image (a) above; a modified image is obtained by swapping the numbers 9 and 4 of the number plate (b); digital watermarking technology allows detecting and highlights the modified areas, as shown on (c).
WATERMARKING ISSUES
Capacity Robustness Transparency Security
TYPES OF DW
Fig. Types of watermarking
Visible watermarking
In visible watermarking, the information is visible in the picture or video.
Invisible watermarking
(a)original image (b) watermarked image
WATERMARK ATTACKS
Active Attacks. Hacker attempts to remove or destroy the
watermark. Passive Attacks. Hacker tries to find if a watermark is present. Removal of watermark is not an aim.
CONTINUED…
Collusion Attacks. Hacker uses several copies of watermarked
data (images, video etc.) to construct a copy with no watermark.
Forgery Attacks. Hacker tries to embed a valid watermark
APPLICATIONS OF DW
ID card security.
Ownership assertion. Copy prevention or control. Fraud and tamper detection.
LIMITATIONS OF DW
Digital watermarking does not prevent copying or distribution.
Digital watermarks cannot survive every possible attack.
CONCLUSION
Digital watermarking is a rapidly evolving area of research and development.
One key research problem that we still face today is the development of truly robust, transparent and secure watermarking technique for different digital media including images, video and audio.
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