A constructive and unifying framework for zero-bit watermarking

In the watermark detection scenario, also known as zero-bit watermarking, a watermark, carrying no hidden message, is inserted in content. The watermark detector checks for the presence of this particular weak signal in content. The article looks at this problem from a classical detection theory point of view, but with side information enabled at the embedding side. This means that the watermark signal is a function of the host content. Our study is twofold. The first step is to design the best embedding function for a given detection function, and the best detection function for a given embedding function. This yields two conditions, which are mixed into one `fundamental' partial differential equation. It appears that many famous watermarking schemes are indeed solution to this `fundamental' equation. This study thus gives birth to a constructive framework unifying solutions, so far perceived as very different.Comment: submitted to IEEE Trans. on Information Forensics and Securit

Oblivious data hiding : a practical approach

This dissertation presents an in-depth study of oblivious data hiding with the emphasis on quantization based schemes. Three main issues are specifically addressed: 1. Theoretical and practical aspects of embedder-detector design. 2. Performance evaluation, and analysis of performance vs. complexity tradeoffs. 3. Some application specific implementations. A communications framework based on channel adaptive encoding and channel independent decoding is proposed and interpreted in terms of oblivious data hiding problem. The duality between the suggested encoding-decoding scheme and practical embedding-detection schemes are examined. With this perspective, a formal treatment of the processing employed in quantization based hiding methods is presented. In accordance with these results, the key aspects of embedder-detector design problem for practical methods are laid out, and various embedding-detection schemes are compared in terms of probability of error, normalized correlation, and hiding rate performance merits assuming AWGN attack scenarios and using mean squared error distortion measure. The performance-complexity tradeoffs available for large and small embedding signal size (availability of high bandwidth and limitation of low bandwidth) cases are examined and some novel insights are offered. A new codeword generation scheme is proposed to enhance the performance of low-bandwidth applications. Embeddingdetection schemes are devised for watermarking application of data hiding, where robustness against the attacks is the main concern rather than the hiding rate or payload. In particular, cropping-resampling and lossy compression types of noninvertible attacks are considered in this dissertation work

Improving the Watermarking Technique to Generate Blind Watermark by Using PCA & GLCM Algorithm

For making sure that the multimedia information is not accessed or modified by unauthorized users, several digital techniques have been proposed as per the growth of internet applications. However, the most commonly used technique is the watermarking technique. The spatial domain method and frequency domain method are the two broader categorizations of several watermarking techniques proposed over the time. The lower order bits of cover image are improved for embedding a watermark through the spatial domain technique. Minimizing the complexity and including minimum computational values are the major benefits achieved through this technique. However, in the presence of particular security attacks, the robustness of this technique is very high. Further, the techniques that use some invertible transformations such as Discrete Cosine Transform (DCT) are known as the frequency domain transform techniques. The image is hosted by applying Discrete Fourier transforms (DFT) and Discrete Wavelet Transform (DWT) techniques. The coefficient value of these transforms is modified as per the watermark for embedding the watermark within the image easily. Further, on the original image, the inverse transform is applied. The complexity of these techniques is very high. Also, the computational power required here is high. The security attacks are provided with more reverts through these methods. GLCM (Gray Level Co Occurrence Matrix) technique is better approach compare with other approach. In this work, GLCM (Gray Level Co Occurrence Matrix) and PCA (Principal Component Analysis) algorithms are used to improve the work capability of the neural networks by using watermarking techniques. PCA selects the extracted images and GLCM is used to choose the features extracted from the original image. The output of the PCA algorithm is defined by using scaling factor which is further used in the implementation. In this work, the proposed algorithm performs well in terms of PSNR (Peak Signal to Noise Ratio), MSE (Mean Squared Error), and Correlation Coefficient values. The proposed methods values are better from the previous work

HDR Image Watermarking

In this Chapter we survey available solutions for HDR image watermarking. First, we briefly discuss watermarking in general terms, with particular emphasis on its requirements that primarily include security, robustness, imperceptibility, capacity and the availability of the original image during recovery. However, with respect to traditional image watermarking, HDR images possess a unique set of features such as an extended range of luminance values to work with and tone-mapping operators against whom it is essential to be robust. These clearly affect the HDR watermarking algorithms proposed in the literature, which we extensively review next, including a thorough analysis of the reported experimental results. As a working example, we also describe the HDR watermarking system that we recently proposed and that focuses on combining imperceptibility, security and robustness to TM operators at the expense of capacity. We conclude the chapter with a critical analysis of the current state and future directions of the watermarking applications in the HDR domain