There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

A wavelet domain watermark encoder and decoder embed and detect auxiliary signals in a media signal, such as a still image, video or audio signal. The watermark encoders and decoders employ techniques that take advantage of processing plural levels of resolution of the signal to embed and detect auxiliary information in the media signal.

Wavelet domain watermarks

http://eee.sutech.ac.ir/sites/eee.sutech.ac.ir/files/Groups/com/DrDanyali/7-A%20new%20robust%20reference%20watermarking%20scheme%20based%20on%20DWT-SVD.pdf

A new robust reference watermarking scheme based on DWT-SVD

The targeted audience for this book is graduate students in engineering and medical statistics courses, and it may be useful for a senior undergraduate statistics course. To get the maximum benefit from this book, one should have a good knowledge and understanding of calculus and sufficient background in elementary probability theory to understand the central limit theorem and the law of large numbers. Some more sophisticated probability terminologies and concepts are defined for a smooth reading of the monograph. This monograph has 10 chapters, including the introduction. Chapter 2 deals with the ageing concept and some usual parametric families of probability distribution are presented in Chapter 3. Parametric and nonparametric statistical inference are nicely treated in Chapters 4 and 5. Chapter 5 also offers tests for exponentiality, which is one of the main feature of the monograph. Chapters 7 and 8 cover two-sample and regression problems, respectively. All of the preceding chapters showcase results for both complete and censored data. One of the interesting contributions is with regard to the analysis of competing risk, which is presented in Chapter 9. Finally, Chapter 10 introduces repairable systems. One of the main strengths of this book is that it introduces the public domain R software and nicely explains how it can be used in computations of methods presented in the book. This book has sufficient material and examples to cover a one semester (13week) course. However, I would be reluctant to adopt this book for one simple reason—there are no exercises. Having said that, the monograph would be useful to some applied researchers in related fields.

Handbook of Statistical Distributions with Applications

This paper presents an optimized watermarking scheme based on the discrete wavelet transform (DWT) and singular value decomposition (SVD). The singular values of a binary watermark are embedded in singular values of the LL3 sub-band coefficients of the host image by making use of multiple scaling factors (MSFs). The MSFs are optimized using a newly proposed Firefly Algorithm having an objective function which is a linear combination of imperceptibility and robustness. The PSNR values indicate that the visual quality of the signed and attacked images is good. The embedding algorithm is robust against common image processing operations. It is concluded that the embedding and extraction of the proposed algorithm is well optimized, robust and show an improvement over other similar reported methods.

Optimized gray-scale image watermarking using DWT-SVD and Firefly Algorithm

In this paper, we will provide an overview of the wavelet-based watermarking techniques available today. We will see how previously proposed methods such as spread-spectrum watermarking have been applied to the wavelet transform domain in a variety of ways and how new concepts such as the multi-resolution property of the wavelet image decomposition can be exploited. One of the main advantages of watermarking in the wavelet domain is its compatibility with the upcoming image coding standard, JPEG2000. Although many wavelet-domain watermarking techniques have been proposed, only few fit the independent block coding approach of JPEG2000. We will illustrate how different watermarking techniques relate to image compression and examine the robustness of selected watermarking algorithms against image compression.

Survey of wavelet-domain watermarking algorithms

In this paper, we investigate a novel joint statistical model for subband coefficient magnitudes of the dual-tree complex wavelet transform, which is then coupled to a Bayesian framework for content-based image retrieval. The joint model allows to capture the association among transform coefficients of the same decomposition scale and different color channels. It further facilitates to incorporate recent research work on modeling marginal coefficient distributions. We demonstrate the applicability of the novel model in the context of color texture retrieval on four texture image databases and compare retrieval performance to a collection of state-of-the-art approaches in the field. Our experiments further include a thorough computational analysis of the main building blocks, runtime measurements, and an analysis of storage requirements. Eventually, we identify a model configuration with low storage requirements, competitive retrieval accuracy, and a runtime behavior, which enables the deployment even on large image databases.

Efficient Texture Image Retrieval Using Copulas in a Bayesian Framework

This article aims at lightweight, blind detection of additive spread-spectrum watermarks in the DWT domain. We focus on two host signal noise models and two types of hypothesis tests for watermark detection. As a crucial point of our work we take a closer look at the computational requirements of watermark detectors. This involves the computation of the detection response, parameter estimation and threshold selection. We show that by switching to approximate host signal parameter estimates or even fixed parameter settings we achieve a remarkable improvement in runtime performance without sacrificing detection performance. Our experimental results on a large number of images confirm the assumption that there is not necessarily a tradeoff between computation time and detection performance.

/pdf/lightweight-detection-of-additive-watermarking-in-the-dwt-23q35zf6b7.pdf

Lightweight Detection of Additive Watermarking in the DWT-Domain

In this paper, we propose a blind watermarking method integrated in the JPEG2000 coding pipeline. Prior to the entropy coding stage, the binary watermark is placed in the independent code-blocks using Quantization Index Modulation (QIM). The quantization strategy allows to embed data in the detail subbands of low resolution as well as in the approximation image. Watermark recovery is performed without reference to the original image during image decompression. The proposed embedding scheme is robust to compression and other image processing attacks. We demonstrate two application scenarios: image authentication and copyright protection.

/pdf/quantization-watermarking-in-the-jpeg2000-coding-pipeline-561umj4n3v.pdf

Quantization Watermarking in the JPEG2000 Coding Pipeline

In this paper, we have a close look at the runtime performance of the intra-component transform employed in the reference implementations of the JPEG2000 image coding standard. Typically, wavelet lifting is used to obtain a wavelet decomposition of the source image in a computationally efficient way. However, so far no attention has been paid to the impact of the CPU's memory cache on the overall performance. We propose two simple techniques that dramatically reduce the number of cache misses and cut column filtering runtime by a factor of 10. Theoretical estimates as well as experimental results on a number of hardware platforms show the effectivity of our approach.

Peter Meerwald

Papers

Survey of wavelet-domain watermarking algorithms

Efficient Texture Image Retrieval Using Copulas in a Bayesian Framework

Lightweight Detection of Additive Watermarking in the DWT-Domain

Quantization Watermarking in the JPEG2000 Coding Pipeline

Cache issues with JPEG2000 wavelet lifting