Watermarking Images in the Frequency Domain by Exploiting Self-Inverting Permutations

Abstract

<p class="MsoNormal"> <span lang="EN-US">In this work we propose efficient codec algorithms for watermarking images that are intended for uploading on the web under intellectual property protection. Headed to this direction, we recently suggested a way in which an integer number </span><i><span lang="EN-US">w</span></i><span lang="EN-US"> which being transformed into a self-inverting permutation, can be represented in a two dimensional (2D) object and thus, since images are 2D structures, we have proposed a watermarking algorithm that embeds marks on them using the 2D representation of </span><i><span lang="EN-US">w</span></i><span lang="EN-US"> in the spatial domain. Based on the idea behind this technique, we now expand the usage of this concept by marking the image in the frequency domain. In particular, we propose a watermarking technique that also uses the 2D representation of self-inverting permutations and utilizes marking at specific areas thanks to partial modifications of the image’s Discrete Fourier Transform (DFT). Those modifications are made on the magnitude of specific frequency bands and they are the least possible additive information ensuring robustness and imperceptiveness. We have experimentally evaluated our algorithms using various images of different characteristics under JPEG compression. The experimental results show an improvement in comparison to the previously obtained results and they also depict the validity of our proposed codec algorithms.</span><span lang="EN-US"><o:p></o:p></span> </p

A publicly verifiable watermarking scheme based on quantum chaos and DWT–DCT

“…The proposed paper uses same technique as provided by author Zhang et al [18]. Author derived its basis from the inspiring contributions in literature [21,24,25]. The role of chaotic sequence generation in the same is inexplicable.…”

Watermarking PDF Documents using Various Representations of Self-inverting Permutations

“…In this section we describe a different approach of embedding algorithm a selfinverting permutation π * into a digital document T , by exploiting the twodimensional representation of permutation π * . The main idea behind the embedding algorithm, we call it Embed SiP.to.PDF-II, is similar of that of algorithm Embed SiP.to.Image-F (see, [11]). The most important of this idea is the fact that it suggests a way in which the permutation π * can be represented with a 2D-representation and since pages of a PDF document T are two dimensional objects that representation can be efficiently marked on them resulting the watermarked PDF document T w ; in a similar way as in our image watermarking approach, such a 2D-representation can be efficiently extracted for a watermarked PDF document T w and converted back to the self-inverting permutation π * .…”

Cripto-esteganografia: imagens inocentes podem transportar arquivos secretos

“…Este trabalho mostra não apenas como podemos guardar uma informação qualquer dentro de uma imagem, mas também como podemos deixá-la protegida através de criptografia. Alguns trabalhos correlatos foram publicados [1,4]. Nosso método, no entanto,é original e de simples implementação, podendo ser utilizado tanto para uso pessoal quanto para a troca de mensagens e arquivos entre duas partes através de uma rede insegura.…”