An Improvemet of Watermarking Methods for Images and Video using Deconvolution Techniques

1.小波图像水印中小波滤波器组的评价：在小波图像水印中，与小波编码类似，小波滤波器组的选择一般影响水印算法的性能。因此，一个自然的问题出现了基于小波的水印。什么是最好的小波滤波器组使用？本文从水印图像的质量和水印的鲁棒性两个方面对小波滤波器组进行了理论上的评价，并试图回答小波水印中的最佳小波滤波器组问题。在此基础上，讨论了正交小波水印算法和双正交小波水印算法的性能，并对两种算法进行了比较 ...更多信息 水印检测的相关性为基础的图像水印方法。在基于相关性的水印方法中，通过计算加水印的图像和要检查其存在的伪随机码之间的相关性来执行水印检测。因此，它的准确性取决于主机图像的特性。在这项研究中，我们首先展示了一个实验结果，某个图像可能会导致水印检测错误。然后，我们已经开发了一个改进版本的水印嵌入过程中，在这种情况下是有效的。改进是通过使用非线性规划算法设计白化滤波器来完成的。数值实验表明，我们预期的良好性能。3.改进的水印提取过程中使用的反卷积技术：在这项研究中，我们一直专注于数字水印技术的基础上修改的频谱系数的图像。我们提出了一个水印嵌入和提取过程的模型，并描述了一个模型的图像处理和攻击的水印图像作为一个卷积模型所造成的水印失真。在此基础上，阐明了水印提取过程中出现检测错误的原因，并将水印检测的改进问题归结为一种盲解卷积问题。然后研究了基于贝叶斯估计的水印检测问题，提出了一种基于EM（Expectation-Maximization）算法的水印检测方法。少

1.On the evaluation of wavelet filter banks for wavelet-based image watermarking : In the wavelet-based watermarking, similar to the wavelet-based coding, the choice of wavelet filter banks generally affects the performance of watermarking methods. Hence a natural question arises for the wavelet-based watermarking. What is the best wavelet filter bank for use ? In this research, we have evaluated wavelet fitter banks used in watermarking theoretically from the viewpoint of the quality of watermarked image and the robustness of watermark, and then tried to answer the best wavelet filter bank problem in the wavelet-based watermarking. Based on the results, we have discussed the performance of the watermarking method using orthogonal wavelet and the watermarking method using biorthogonal wavelet, and carried out the comparison between the two methods.2.An improvement of the watermark detection in the correlation-based image watermarking methods : This research aims to improve the accuracy … More of watermark detection in correlation-based watermarking methods for images. In the correlation-based watermarking method, watermark detection is carried out by computing the correlation between a watermarked image and a pseudorandom code to be checked for the presence. Hence its accuracy depends on the characteristics of host images. In this research, we have firstly shown an experimental result that a certain image may cause watermark detection errors. Then we have developed an improved version of the watermark embedding process to be effective in such a situation. The improvement is accomplished by designing a whitening filter using a nonlinear programming algorithm. Numerical experiments have shown good performance as expected by us.3.An improvement of watermark extracting process using the deconvolution technique: In this research, we have focused on digital watermarking techniques based on modifying the spectral coefficient of an image. We have presented a model of the watermark embedding and extraction processes and described a model of watermark distortion caused by image processing and attack of watermarked image as a convolution model. Based on the model, we have clarified the reason why detection errors occur in the watermark extraction process and formulated the problem of the improvement of the watermark detection as a kind of blind deconvolution problem. Then we have studied the watermark detection problem using Bayesian estimation technique, and as a solution to this problem, proposed a watermark detection method based on the EM (Expectation-Maximization) algorithm. Less