21,356 research outputs found
A constructive and unifying framework for zero-bit watermarking
In the watermark detection scenario, also known as zero-bit watermarking, a
watermark, carrying no hidden message, is inserted in content. The watermark
detector checks for the presence of this particular weak signal in content. The
article looks at this problem from a classical detection theory point of view,
but with side information enabled at the embedding side. This means that the
watermark signal is a function of the host content. Our study is twofold. The
first step is to design the best embedding function for a given detection
function, and the best detection function for a given embedding function. This
yields two conditions, which are mixed into one `fundamental' partial
differential equation. It appears that many famous watermarking schemes are
indeed solution to this `fundamental' equation. This study thus gives birth to
a constructive framework unifying solutions, so far perceived as very
different.Comment: submitted to IEEE Trans. on Information Forensics and Securit
High order finite element calculations for the deterministic Cahn-Hilliard equation
In this work, we propose a numerical method based on high degree continuous
nodal elements for the Cahn-Hilliard evolution. The use of the p-version of the
finite element method proves to be very efficient and favorably compares with
other existing strategies (C^1 elements, adaptive mesh refinement, multigrid
resolution, etc). Beyond the classical benchmarks, a numerical study has been
carried out to investigate the influence of a polynomial approximation of the
logarithmic free energy and the bifurcations near the first eigenvalue of the
Laplace operator
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