摘要
图像在有损压缩、数/模转换过程中会有不同程度的噪声。噪声对图像的影响只能用概率统计方法来评估。水印作品在存储之前化为整数值时会出现量化失真。量化给作品带来的误差大小取决于该项位于量化因子两个整数倍之间的位置;量化对水印的影响是由噪声和水印参考模板之间相关的期望值决定的;量化误差与水印无关,而当量化因子足够大时,量化器的输出为零。
In the process of lossy compression and D/A conversion, the image has different noise. The impact of noise on the image can only use probability statistical method. When the watermark works become integar value before storing, the quantization distortion is come true. The error caused by quantization for works which depends on location betwean quantitative factorrs two integar multiple. The impact on watermark of quantization is decided by expectation between neise and reference template, quantization error has nothing to do with watermark, when the quantitative factor is large enough, the quantizer＇s output is 0.
出处
《现代电子技术》
2009年第14期93-94,共2页
Modern Electronics Technique
关键词
图像
水印
噪声
量化
image
watermark
noise
quantization
