A multifunctional double-watermarking algorithm of color digital image for copyright protection and authentication
A new multifunctional double-watermarking algorithm of digital image was proposed.The original imagewas decomposed into R,G,B,three color components.Copyright watermark that modulated by sequence spread spectrumwas embedded in B component's intermediate frequency coefficients.Authentication watermark was embedded in lifting wavelet coefficients quantified,which was made by G component.The two kinds of watermark can be embedded at the same time or separately.The experimental results show that copyright watermark can well protect from shear transformation attack and it has good robustness and imperceptibility.The authentication watermark algorithm can realize tamper detection and location well.
In ATM networks, source policing functions are crucial for ensuring that user traffic does not exceed the negotiated quality of service. Many different source policing functions have been proposed, including the well known Leaky Bucket scheme [1]. However, recent studies have shown that there are a number of problems in using this scheme. One criticism is that it does not penalize violating traffic sufficiently to reduce its impact on non-violating traffic source [2]. The purpose of this paper is to evaluate modifications to the Leaky Bucket scheme which will enforce the policing function more strictly, and compare with some other proposed techniques such as the Peak Counter scheme [3]. Since analytical analysis is in most cases intractable, simulation is the main tool for this study.