The weakness of classical watermarking methods is the vulnerability to geometrical distortions that widely occur during normal use of the media. In this letter, a new image- watermarking method is presented to resist ...The weakness of classical watermarking methods is the vulnerability to geometrical distortions that widely occur during normal use of the media. In this letter, a new image- watermarking method is presented to resist Rotation, Scale and Translation (RST) attacks. The watermark is embedded into a domain obtained by taking Radon transform of a circular area selected from the original image, and then extracting Two-Dimensional (2-D) Fourier magnitude of the Radon transformed image. Furthermore, to prevent the watermarked image from degrading due to inverse Radon transform, watermark signal is inversely Radon transformed individually. Experimental results demonstrate that the proposed scheme is able to withstand a variety of attacks including common geometric attacks.展开更多
Based on the scalar wave equation, making use of the ray approximation of the reflected seismic data (CMP or CSP gathers), the authors derive respectively the projection function of the primary waves and multiple wave...Based on the scalar wave equation, making use of the ray approximation of the reflected seismic data (CMP or CSP gathers), the authors derive respectively the projection function of the primary waves and multiple waves at the near offset (CMP or CSP gathers) in the parabolic Radon transform(PRT)domain. From the geometric point, the authors prove that the energy of the reflection still distributes along hyperbola which has higher curvature in the PRT domain and becomes some energy masses. So the primary waves and the multiple waves which interweave each other in ( x, t ) domain can be completely separated, which helps the multiple waves eliminated by filtering or muting. It is important for the analysis of velocity and the separator and elimination of multiple waves.展开更多
以便在严肃的噪音克服差的精确性的缺点和传统的波长计算方法的非严肃的直觉说，一个修订的氡变换算法被使用建议一而不是使用近似用于波长的波浪质地直线评价。第一，雷达图象的氡变换被分析。然后，与波浪质地结合了获得它的恰当的直...以便在严肃的噪音克服差的精确性的缺点和传统的波长计算方法的非严肃的直觉说，一个修订的氡变换算法被使用建议一而不是使用近似用于波长的波浪质地直线评价。第一，雷达图象的氡变换被分析。然后，与波浪质地结合了获得它的恰当的直线，距离在直线之间被计算得到波长。最后，算法在 PC 上与 Matlab 被规划。试验性的结果证明建议算法能与好可见性改进波长的评价精确性。展开更多
文摘The weakness of classical watermarking methods is the vulnerability to geometrical distortions that widely occur during normal use of the media. In this letter, a new image- watermarking method is presented to resist Rotation, Scale and Translation (RST) attacks. The watermark is embedded into a domain obtained by taking Radon transform of a circular area selected from the original image, and then extracting Two-Dimensional (2-D) Fourier magnitude of the Radon transformed image. Furthermore, to prevent the watermarked image from degrading due to inverse Radon transform, watermark signal is inversely Radon transformed individually. Experimental results demonstrate that the proposed scheme is able to withstand a variety of attacks including common geometric attacks.
文摘Based on the scalar wave equation, making use of the ray approximation of the reflected seismic data (CMP or CSP gathers), the authors derive respectively the projection function of the primary waves and multiple waves at the near offset (CMP or CSP gathers) in the parabolic Radon transform(PRT)domain. From the geometric point, the authors prove that the energy of the reflection still distributes along hyperbola which has higher curvature in the PRT domain and becomes some energy masses. So the primary waves and the multiple waves which interweave each other in ( x, t ) domain can be completely separated, which helps the multiple waves eliminated by filtering or muting. It is important for the analysis of velocity and the separator and elimination of multiple waves.
文摘以便在严肃的噪音克服差的精确性的缺点和传统的波长计算方法的非严肃的直觉说，一个修订的氡变换算法被使用建议一而不是使用近似用于波长的波浪质地直线评价。第一，雷达图象的氡变换被分析。然后，与波浪质地结合了获得它的恰当的直线，距离在直线之间被计算得到波长。最后，算法在 PC 上与 Matlab 被规划。试验性的结果证明建议算法能与好可见性改进波长的评价精确性。
