DESIGN AND IMPLEMENTATION OF THE ROBUST WATERMAKING TECHNIQUE FOR THE RAW DIGITAL VIDEO BASED ON CDMA

Abstract

The focus of the project entitled “DESIGN AND IMPLEMENTATION OF THE ROBUST WATERMARKING TECHNIQUE FOR THE RAW DIGITAL VIDEO BASED ON CDMA ” is to ultimately embed a robust Watermark in the digital Video that will identify its Owner unambiguously. Spread spectrum has been used as a technique for secure communications for a long time. For still image Watermarking , spread spectrum has been the method of choice for some time. In this project we argue that spread spectrum in the form of CDMA has a more natural application in the Watermarking of uncompressed digital Video. The reason for this sentiment is that digital Video, by virtue of its time-space property, fits the direct sequence spread spectrum more readily. The problem, however, is that conventional CDMA achieves its data-hiding capability by a massive increase in bit-rate. Successful implementation of CDMA for Video Watermarking, therefore, requires a reformulation of the concept. The digital Video, here, is modeled as a bitplane stream along the time axis. Previous research indicates that lower bitplanes of the digital frames have to be modified in order to embed the information in a reliable and robust way. In spread spectrum communications, a narrow-band signal is spread across a wide band of frequencies. This can be accomplished by modulating the narrow-band signal (the Watermark information in our case) with a wide-band signal, such as Gaussian noise. The spread Watermark signal is similar to the noise already present in the image signal and therefore hard to detect.This led to the development of the discussed Watermarking scheme. Using a modified m-sequence, bitplanes of specific order are pseudorandomly marked for Watermarking. The desired Watermark is mapped to a single bitplane and spread via another 2D m-sequence, not necessarily related to the first one, along a stream parallel to that of the Video. The tagged planes are removed and replaced by the spread Watermark. Several types of attacks ( regular and/or random frame removal.) have been preformed on the Watermarked Video to check the reliability & robustness of the developed technique. The results show that the above approach resists noise as well as attacks on destroying synchronization at the Watermark detector.