Digital watermarking technology
¨ What is digital watermark
In the schedule life, in order to identify the true pseudo of banknotes, people usually put the banknotes to the light source, will find that the real banknotes have clear image information, which is our familiar "watermark". The use of watermarking technology is because the watermark has its own unique nature: the first watermark is a borous imprint must be placed in a particular environment. It does not affect the use of the item; the production and replication of the second watermark Comparable, special processes and materials are needed, and the watermark on the print is difficult to get off. Therefore, watermarks are often applied to important printers such as checks, certificates, passports, invoices, and a long-term way to determine the authenticity of printed products is to test whether it contains watermarks.
Today's digital age, multimedia digital world is colorful, digital products have almost affected everyday life. How to protect these digital products related to us, such as copyright protection, information security, data certification, and access control, etc., it is increasingly valued and incurred. Drawing on the meaning and function of ordinary watermarks, people use similar concepts to protect multimedia data such as digital images, digital music, thus generating the concept of "digital watermark". The so-called "digital watermark" is some digital information added to multimedia data, for example, adds a film information to the digital photo, adding a movie company information, and so on. Similar to the characteristics of ordinary watermarks, digital watermarks are almost invisible in multimedia data (such as digital photos), and it is difficult to be destroyed. So digital watermarks can be available in today's computer and Internet age.
¨ What can digital watermarks?
The initial concept and method of propaning digital watermarks are copyright protection for multimedia data. With the development of computers and Internet, more and more artworks, inventions or creativity begins to express in the form of multimedia data, such as with digital camera photography, watch movies with digital cinema, listen to music with MP3 players, with computer painting Painting and more. The multimedia data involved in all activities contain a lot of money. Compared with the author's hardships, tampering, forgery, copying and illegal release of the original works become a light and easy task than the hardships of these multimedia data. Anyone can easily create a copy of multimedia data. Compare the original data, the copied multimedia data does not have any mass loss, which can completely "clone" multimedia data. Therefore, how to protect these data is an urgent problem to be solved. Then the digital watermark is exactly the effective means of solving such "copyright issues". For example, the previous painter uses the author of the seal or the author of the logo, then today he can add his name to the work of the copyright through digital watermarking. Similarly, audio-visual companies can also add information such as the company's name, symbol to the published tape, CD disc. This protects the copyright of multimedia data by tracking digital watermark information in multimedia data.
In addition to copyright protection, digital watermarking technology has great use in authenticity certification of document (print, electronic document, etc.), such as the red head file issued by the government department, the traditional method of document authentication is paper paper. , Whether the seal or steel print is in line with the norms and standards, and the disadvantage is that the paper, seal or steel print is easily forged. In particular, the seal, although the government departments have strict regulations on the management and production of the seal, but there is still a saying of "a radish carving chapter". This shows that the traditional method has extremely imperfect places. Use digital watermarking technology to effectively solve this problem. As a digital watermark as an information carrier, some information is added to the red header file, so that the document not only seals or steel prints, but also has difficult-topected digital watermark information, which greatly increases the difficulty of file being forged. Adding digital watermark information to a document, which means that some information can be written twice in the document. For example, the name of the passport holder is obviously printed in the passport, or it can be used as a digital watermark in the avatar. If someone wants to fake a passport by replacing the avatar, then it is possible to detect the passport by scanning the passport. The watermark information hidden in the avatar does not meet the name of the name on the passport, thus discovering the forged passport. In addition, digital watermarks are also used to do access control and replication control of multimedia data. For example, the secret digital watermark information in the CD data disk can have conditionally control what kind of person can access the content in the CD disk. At present, DVD has already hot domestic electronic market, and many large companies have begun to study how to apply digital watermark systems to improve DVD access and replication control. For example, it is hoped that the DVD player in the consumer is allowed to replicate the home video or expired TV program. The digital watermark added in the home video does not contain any control identifier, the digital watermark identifier in the TV program is "copy once", " Copying multiple times, while commercial video programs identify "not allowed replication", the related playback devices will determine these digital watermarks to identify and work accordingly. This ensures that consumers are privately replicated, and the freedom of exchange shows, and effectively control the business infringement. All solutions have been formed, the problem is the security, effectiveness, and conciseness of the solution require further test, which is temporarily available to DVD manufacturers and users.
Digital watermarking technology can also be applied to information security communication. Since people are difficult to know that digital watermark information is existed in multimedia data, some important information can be hidden in ordinary multimedia data during transmission, thereby avoiding third-party eavesdropping and monitoring. Foreign Newspaper Report Terrorist Leader - Bin Laden uses public released digital watermarking technology, will give the base organization's instructions to hide in a normal digital photo through digital watermark, and then released to the BBS of some websites, Base Organization members according to the contract The rule extracts the digital watermark information in the digital photo. This approach is highly concealed compared to ordinary telephone communications, email communications, and encrypted communications, which is not easy to monitor, and it is difficult to be aware.
¨ Watermark's future
There are still many other uses in digital watermarking technology, and its application is also expanding. To completely explain the future of digital watermark applications, the industry has increasing interest in digital watermarking technology in replication protection and paper medium, such as such as watermarking technology to protect banknotes, checks, invoices, etc. Wait. In addition to technological development, marketing and business planning is also extremely important, and there is a need for a deep analysis and strategic plan. Technical promotion and popularization are also indispensable to ensure that the market is prepared for receiving digital watermarking technology.
Hunnish
A bare code http://www.assuredigit.com
