In this paper, a new technique is proposed for rotation, scaling and translation （RST） invariant image watermarking based on log-polar mappings （LPM） and phase-only filtering （POF）. The watermark is embedded in ...In this paper, a new technique is proposed for rotation, scaling and translation （RST） invariant image watermarking based on log-polar mappings （LPM） and phase-only filtering （POF）. The watermark is embedded in the LPM of Fourier magnitude spectrum of the original image, and a small portion of resulting LPM spectrum is used to calculate the watermark positions. This technique avoids computing inverse log-polar mapping （ILPM） to preserve the quality of the watermarked image, and avoids exhaustive search to save computation time and reduce false detection. Experimental results demonstrate that the digital watermarking technique is invariant and robust to rotation, scaling, and translation transformation.展开更多
针对传统对数极坐标傅立叶变换(log-polar mapping based Fourier transform,LPMFT)在大尺度、大旋转及大平移变换情况下不能精确估计图像对之间的变换参数,提出基于层次化及最小二乘的图像配准方法(multi-resolution analysis and leas...针对传统对数极坐标傅立叶变换(log-polar mapping based Fourier transform,LPMFT)在大尺度、大旋转及大平移变换情况下不能精确估计图像对之间的变换参数,提出基于层次化及最小二乘的图像配准方法(multi-resolution analysis and least square optimization,MALSO):首先,使用小波变换将图像分解为多分层结构,并将每层的低频部分作为待匹配图像;其次,在每层中,引入窗口函数及自适应滤波函数以减少谱泄漏,混叠及插值误差的影响;最后,构建一个代价函数,并通过最小二乘法求解最优参数.实验表明,该方法既满足大尺度,大旋转及大平移参数准确估计要求,又比LPMFT对遮挡更具鲁棒性,有一定的理论及应用价值.展开更多
文摘In this paper, a new technique is proposed for rotation, scaling and translation （RST） invariant image watermarking based on log-polar mappings （LPM） and phase-only filtering （POF）. The watermark is embedded in the LPM of Fourier magnitude spectrum of the original image, and a small portion of resulting LPM spectrum is used to calculate the watermark positions. This technique avoids computing inverse log-polar mapping （ILPM） to preserve the quality of the watermarked image, and avoids exhaustive search to save computation time and reduce false detection. Experimental results demonstrate that the digital watermarking technique is invariant and robust to rotation, scaling, and translation transformation.
基金Supported by National Natural Science Foundation of China(61571313,u1633126)National Key Research and Development Program(2016YFB08-00600)+1 种基金International Science and Technology Cooperation Project of Chengdu City(2015–GH02–00008–HZ)Young Talent Project in Science and Technology Innovation Program of Sichuan Province(2016017)
文摘针对传统对数极坐标傅立叶变换(log-polar mapping based Fourier transform,LPMFT)在大尺度、大旋转及大平移变换情况下不能精确估计图像对之间的变换参数,提出基于层次化及最小二乘的图像配准方法(multi-resolution analysis and least square optimization,MALSO):首先,使用小波变换将图像分解为多分层结构,并将每层的低频部分作为待匹配图像;其次,在每层中,引入窗口函数及自适应滤波函数以减少谱泄漏,混叠及插值误差的影响;最后,构建一个代价函数,并通过最小二乘法求解最优参数.实验表明,该方法既满足大尺度,大旋转及大平移参数准确估计要求,又比LPMFT对遮挡更具鲁棒性,有一定的理论及应用价值.
