Hyperbolic RDM for Nonlinear Valumetric Distortions
Hyperbolic RDM for Nonlinear Valumetric Distortions
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DOI：
10.1109/tifs.2008.2011080
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发表时间：
2009-03-01
影响因子：
6.8
通讯作者：
Scagliola, Michele
中科院分区：
文献类型：
--
作者：
Guccione, Pietro;Scagliola, Michele
基于量化的水印技术对量值缩放很敏感，量值缩放是应用于图像和视频的一种广泛的失真，如对比度变化或伽马校正。已经提出了几种方法来对抗计值攻击，但解决该问题的常见方法是只考虑线性攻击。提出了一种对有理抖动调制(RDM)数据隐藏方案的扩展，该方案对由幂规律攻击建模的非线性失真具有健壮性。该算法利用了像素值从笛卡尔坐标到双曲坐标的适当映射。这种映射能够使问题类似于经典的RDM方案，因为固定的乘法标度被抵消，而非线性失真的指数化为增益标度。通过将该水印方案应用于高斯宿主图像和真实图像，验证了该方法的有效性；实验结果证实了该方法对幂函数攻击的内在不变性。仿真结果表明，在加入高斯白噪声的情况下，该方案具有较好的误比特率。本文的理论分析支持了嵌入域的性质对测量误码率的影响。
Quantization-based watermarking techniques are sensitive to valumetric scaling, a wide class of distortions applied to images and videos, such as contrast change or gamma correction. Several methods have been proposed to counteract valumetric attacks, but the common approach to the problem is to take only the linear ones into account. This paper presents an extension to the rational dither modulation (RDM) data-hiding scheme which provides robustness against nonlinear distortions modelled by a power-law attack. The algorithm makes use of proper mapping of the pixel values from the Cartesian to hyperbolic coordinates. This mapping is able to render the problem similar to the classical RDM scheme, since fixed multiplicative scaling is cancelled out while the exponentiation of a nonlinear distortion is transformed into a gain scaling. The validity of the approach has been confirmed by applying the watermarking scheme to Gaussian host and real images; experimental results confirm its intrinsic invariance against the power-law attack. Finally, it will be shown that under the white Gaussian noise addition, the proposed scheme achieves a good bit-error rate (BER). The measured BER is affected by the properties of the embedding domain, as supported by the theoretical analysis given in this paper.