Development of Image Protection and Management Systems using Digital Watermarking Techniques

(1)图像和视频数字水印方法的发展：我们提出了一种新的水印方法，静止图像和视频使用小波变换。我们已经证实，这种方法是强大的对常见的图像处理操作，如有损压缩JPEG和MPEG，添加噪声，降低灰度级，和StirMark攻击。此外，该方法使我们能够区分恶意更改，如修改或伪造图像的一部分，从普通图像处理操作产生的非恶意更改。(2)在频域数字水印算法性能评价方面：重点研究了基于量化和相关性的频域数字水印算法，提出了水印嵌入和提取系统模型。然后，利用该模型，分析了各种水印算法，并提出了水印性能的评价方法。因此，我们可以知道有多少位能够被嵌入，以及应该设置多大的嵌入强度。此外，我们还讨论了基于DWT和DCT的水印方法的改进。(3)图像数据保护与管理系统的开发：基于上述研究结果，我们提出了以下几种图像数据保护与管理系统：（a）MPEG视频播放与复制控制系统。(b)数字图像检索与验证系统。(c)并通过实验的方法，在Windows PC平台上实现了一个水印嵌入和提取软件。

(1) Development of digital watermarking method for images and video : We have proposed a new watermarking method for both still images and video using the wavelet transform. We have confirmed that this method is robust against common image processing operations like lossy compression as JPEG and MPEG, adding noise, reduction of grayscale level, and StirMark attacks. Furthermore, this method enables us to distinguish malicious changes such as modifying or forging a part of an image from non-malicious changes resulting from common image processing operations.(2) On the evaluation of performance of digital watermarking method in the frequency domain : We have focused on the quantization- and correlation-based watermarking methods in the frequency domain and suggested the model of watermark embedding and extraction system. Next, using this model, we have analyzed the watermarking methods and proposed how to evaluate its performance. As a result, we can know how many bits are able to be embedded and how large the embedded intensity should be set. Furthermore, we have discussed the improvement of the DWT- and DCT-based watermarking methods.(3) Development of image data protection and management system : Based on the above results, we have proposed several image data protection and management systems as follows :(a) Playback- and copy-control system for MPEG video.(b) Retrieval and verification system for digital images.(c) Authentication and protection system for JPEG images.Furthermore, we have produced a watermark embedding and extraction software for Windows PC by way of experiment.