Real Time Implementation of Digital Watermarking Algorithm for Image and Video Application
Watermarking - Volume 2
Cryptography: It scrambles a message into a code to obscure its meaning. Scrambling of message is done with help of secret key. Scrambling message called as encrypted and it is again decrypted with that secret key only. Cryptography provides security to message. Steganography: With Steganography, the sender would hide the message in a host file. The host file or cover message, is the file that anyone can see. When people use this techique, they often hide the true intent for communicating in a
... ore common place communication scenario. In steganography, usually the message itself is of value and must be protected through clever hiding techniques and the "vessel" for hiding the message is worthless. Watermarking: It is the direct embedding of additional information into the original content or host signal. Ideally, there should be no perceptible difference between the watermarked and original signal and the watermark should be difficult to remove or alter without damaging the host signal. In watermarking, the effective coupling of message to the vessel which is the digital content is of value and the protection of the content is crucial. Digital watermarking These are the parameters important for digital watermarking. a. Transparency b. Security c. Ease of embedding and retrieval d. Robustness e. Effect on bandwidth f. Interoperability a. Transparency: The most fundamental requirement for any Watermarking method shall be such that it is transparent to the end user. The watermarked content should be consumable www.intechopen.com Real Time Implementation of Digital Watermarking Algorithm for Image and Video Application 67 at the intended user device without giving annoyance to the user. Watermark only shows up a watermark-detector device. b. Security: Watermarked information shall only be accessible to only authorized parties. They only have the right to alter the Watermark content. Encryption can be used to prevent unauthorized access of the watermarked data. c. Ease of embedding and retrieval: Ideally, Watermarking on digital media should be possible to be performed on the fly. The computation needed for the selected algorithm should be least. d. Robustness: Watermarking must be robust enough to withstand all kinds for signal processing operations attacks or unauthorized access. Any attempt, whether intentionaly or unintentionaly, that has a potential to alter the data content is considered as an attack. Robustness against attack is a key requirement for Watermarking and the success of this technology for copyright protection depends on its stability against attacks. e. Effect on bandwidth: Watermarking should be done in such a way that it does not increase the bandwidth required for transmission. If Watermarking becomes a burden for the available bandwidth, the method fails. f. Interoperability: Digitally watermarked content shall still be interoperable so that it can be seamlessly accessed through heterogeneous networks and can be played on various plays out devices that may be aware or unaware of watermarking techniques.