CAJ | 학술논문

当前数字水印对常见的图像处理攻击如高斯噪声、中值滤波、有损压缩等具有较强的抵抗能力，但其抵抗剪切、缩放等几何攻击的能力较差。因此，为提高数字水印的鲁棒性，结合尺度不变特征变换算子和视觉感知模型，提出一种基于不变特征的水印嵌入方法。基于广义高斯分布模型对小波系数进行刻画，并根据二值假设检验理论确定水印的检测阈值，由此进一步给出水印虚警和漏警之间的工作特性曲线关系。实验仿真结果表明提出的水印方法在抗压缩、叠加噪声、缩放、剪切、旋转等攻击时具有较好的鲁棒性能。
당전수자수인대상견적도상처리공격여고사조성、중치려파、유손압축등구유교강적저항능력，단기저항전절、축방등궤하공격적능력교차。인차，위제고수자수인적로봉성，결합척도불변특정변환산자화시각감지모형，제출일충기우불변특정적수인감입방법。기우엄의고사분포모형대소파계수진행각화，병근거이치가설검험이론학정수인적검측역치，유차진일보급출수인허경화루경지간적공작특성곡선관계。실험방진결과표명제출적수인방법재항압축、첩가조성、축방、전절、선전등공격시구유교호적로봉성능。
The existing image watermarking algorithm is of good robustness when against some common image processing attacks such as Gaussian noise, median filtering and lossy compression, etc.However, the robustness of watermark is poor when against some geometric attacks such as cropping and scaling , etc.Therefore, in order to improve the robustness of watermark , an embed-ded watermarking method is proposed based on invariant feature by combining the scale invariant feature transform and visual model.In the detection scheme , the probability density function of wavelet coefficients which in mid-frequency sub-band is mod-eled by the generalized Gaussian distribution model and the watermark decision threshold is determined by using the binary hy -pothesis theory.Furthermore, the receiver operating characteristic (ROC) curve between the probability of false alarm and the probability of detection is derived .Experimental results demonstrate that the proposed method is of good robustness when against some attacks such as JPEG compression , additive white Gaussian noise , scaling, cropping and rotation etc .