18-12-2009, 08:58 PM
Project Name: Mat Lab Based water marking
In this project our main aim to add a watermark in image. This project is useful for sites like SANTA BANTA.COM specially they have images to show on site, the user has to download images after viewing it on site, If there is no watermark than user will get image without paying to service provider, so to avoid this provider will add a watermark on their image and only than upload it for demo purposes. It is also helpful in some websites where some products images is required to show. So same purpose is there as for santabanta.com. In the project you have its GUI like shown below:
Projectâ„¢s GUI during start mode
You can load image by pressing load button after writing image name as Ëœ1.jpgâ„¢ or any other image name that is available in your Mat Lab root directory in the edit box available just in between original static text and load push button. And than press the load button to show image in original axis. And same for the watermark part just write the WATERMARK.JPG in between watermark static text and load WM button. After this press start button, this will give result in watermarked image, now to save image press save after writing new image name. To check the saved image load image by writing same name as is used during saving time, in check edit box. And then press check button this will open the image in new figure.
Information Hiding is a general term encompassing
Â¢ Two important subdisciplines are: steganography and
â€œHiding: keeping the existence of the information secret
â€œHiding: making the information imperceptible
Â¢ Information hiding is different than cryptography
(cryptography is about protecting the content of
Watermark & Watermarking
Although different authors use different meanings for the word 'watermark', it is mostly order to convey the hidden data. Watermarking means the process of embedding information into another object/signal can be termed as watermarking. Watermarking (now-a-days) is mainly used for copy-protection and copyright-protection. Historically, watermarking has been used to send ``sensitive'' information hidden in another signal Watermarking has its applications in image/video copyright protection. Watermarking is closely related to steganography, but there differences between the two: In watermarking the message is related to the cover. Steganography typically relates to covert point-to-point communication between two parties. Therefore, steganography requires only limited robustness Watermarking is often used whenever the cover is available to parties who know the existence of the hidden data and may have an interest in removing it. Therefore, watermarking has the additional notion of resilience against attempts to remove the hidden data
Watermarks are inseparable from the cover in which they are embedded. Unlike cryptography, watermarks can protect content even after they are decoded
A watermark is a pattern made in high-quality papers by means of a raised or indented design that comes in contact with the paper when it is approximately 90% water and 10% fibers. The watermark designs are spaced at specific internals (depending on the frequency of appearance required in the finished sheet) along the surface of a skillfully crafted wire roll called a Dandy roll. As the revolving Dandy roll comes in contact with the fibers, the raised or indented designs displace the fiber which produces the pattern visible in the finished sheet known as a watermark.
Types of Watermarks:
Wire Marks: This design consists of fine wires soldered to the surface of the Dandy roll cover. While the paper is still being formed, the stock passes under the Dandy roll and the design displaces some of the fibers to form the watermark pattern. As a result, the paper is more translucent in this area and the watermark appears lighter than its surrounding area. For technical reasons, it is necessary to construct Dandy rolls used for watermarking the heavier bond papers slightly different than those used for watermarking onion skin papers. Therefore, it is not possible to secure on Dandy roll - with the same design - for watermarking both bonds and onion skins. Two separate rolls are required.
Shaded Marks: This type of design is depressed into the cover of the Dandy roll similar to reverse engraving. As the Dandy roll presses on the paper being formed, compression occurs everywhere but in the cutout design. Fibers this depressed area, which results in a watermark pattern slightly darker than its surrounding area with a pronounced embossed appearance. In order for the fibers to accumulate in the detailed cutout areas of the design, certain manufacturing refinements are necessary that can sometimes affect the strength, formation or degree of obtainable cockle. It is also possible to furnish watermarks that are a combination of both the wire and shaded styles.
History of Watermarking
More than 700 years ago, watermarks were used in Italy to indicate the paper brand and the mill that produced it By the 18th century watermarks began to be used as anti counterfeiting measures on money and other documents. The term watermark was introduced near the end of the 18th century. It was probably given because the marks resemble the effects of water on paper. The first example of a technology similar to digital watermarking is a patent filed in 1954 by Emil Hembrooke for identifying music works. In 1988, Komatsu and Tominaga appear to be the first to use the term digital watermarking. About 1995, interest in digital watermarking began to mushroom.
1. Copy Protection
Copy protection attempts to find ways, which limits the access to copyrighted material and/or inhibit the copy process itself. Examples of copy protection include encrypted digital TV broadcast, access controls to copyrighted software through the use of license servers and technical copy protection mechanisms on the media. A recent example is the copy protection mechanism on DVDs. However, copy protection is very difficult to achieve in open systems, as recent incidents (like the DVD hack - DeCss) show.
2. Copyright protection
Copyright protection inserts copyright information into the digital object without the loss of quality. Whenever the copyright of a digital object is in question, this information is extracted to identify the rightful owner. It is also possible to encode the identity of the original buyer along with the identity of the copyright holder, which allows tracing of any unauthorized copies. The most prominent way of embedding information in multimedia data is the use of digital watermarking.
Whereas copy protection seems to be difficult to implement, copyright protection protocols based on watermarking and strong cryptography are likely to be feasible.
3. Content Authentication
Embed a watermark to detect modifications to the cover. The watermark in this case has low robustness, fragile
4. Transaction Tracking
Embed a watermark to convey information about the legal recipient of the cover
This is useful to monitor or trace back illegally produced copies of the cover
This is usually referred to as fingerprinting
5. Broadcast Monitoring
Embed a watermark in the cover and use automatic monitoring to verify whether cover was broadcasted as agreed
The digital age has simplified the process of content delivery and has increased the ease at which the buyer can re-distribute the content, thus denying the income to the seller. Images published on the internet is an example of such content. This section will deal with questions related to image watermarking.
Visible and Invisible Watermarking
Visibility is a term associated with the perception of the human eye. A watermarked image in which the watermark is imperceptible, or the watermarked image is visually identical to its original constitutes a invisible watermarking. Examples include images distributed over internet with watermarks embedded in them for copyright protection. Those which fail can be classified as visible watermarks. Examples include logos used in papers in currencies.
Consider the following scenario: Alice, the copyright holder, inserts her own watermark into some object, locks the original away and keeps selling the marked image. Bob can now try to insert his own watermark into the already marked object. In case of a dispute, both Alice and Bob are able to prove the presence of "their" watermark and claim ownership of the document. How can this situation be resolved?
The "traditional" answer is: look at the objects, Alice and Bob claim to be the original. Alice's original should not contain a watermark, whereas Bob's "original" must contain Alice's watermark (if we assume that Bob cannot remove marks). This situation would indicate that Bob inserted his watermark after Alice and so one may conclude that Alice is the rightful owner.
Unfortunately, sometimes the situation is not that simple. It has been shown that, in particular class of watermarking schemes, Bob can insert his watermark in a way that it also seems to be present in the copy Alice locked away (although he has no access to it). So Alice's original contains Bob's mark and Bob's "original" contains Alice's mark. This type of attack is called "inversion attack" or more "dead lock attack". There is no way to resolve copyright ownership in this case. This result indicates that watermarking "alone", that is without a carefully designed protocol around it, will not suffice to resolve the copyright situation