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quantisierungs index modulated (qim) embedding a digital watermark in a multimedia signal
quantisierungs index modulated (qim) embedding a digital watermark in a multimedia signal
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机译:在多媒体信号中嵌入数字水印的量化指数调制(qim)
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摘要
The invention addresses the problem of scale degradations that may occur in watermarking schemes based on quantization index modulation (QIM). In accordance with the invention, the quantization step size (D) being employed by the embedder (11) and detector (21) is derived (12, 22) from a measurable characteristic parameter which has the property that, when the applied signal is scaled by a factor (a), it is scaled by substantially the same factor. In a preferred embodiment, said parameter is the square root of the energy of the signal (), and the quantization step is a predetermined fraction (a) thereof.
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