-Digital watermarking is a technique of embedding pieces of information into digital data such as text, audio, video, and still images that can be detected or extracted later to show authentication about the data. Watermark is hidden information in the image(s) and is so designed that it does not degrade/distort the quality of the image and still keeps the information. Digital watermarking is b...

Multimedia data are mainly in digital form due to advantages of digital domain compared to analog domain. These advantages can be grouped into several categories. Firstly, digital multimedia data authoring is easier and more robust to authoring errors. Editing and modifying data can be accomplished relatively easily. Secondly, digital multimedia data can be delivered over computer networks with...

Text documents can be watermarked by patterning the inter-word spaces. This paper proposes a text watermarking algorithm that exploits the novel concepts of word classification and inter-word space statistics. The words are classified using some features. Several adjacent words are grouped into a segment, and the segments are also classified using the word class information. The same amount of ...

a watermarking scheme for Grayscale image isproposed based on a family of the chaotic maps and discretecosine transform. Jacobian Elliptic mapis employed to encrypt ofwatermarked logo. Piecewise nonlinear chaotic map is also usedto determine the location of DCT coefficients for the watermarkembedding. The purpose of this algorithm is to improve theshortcoming of watermarking such as small key s...

One of the most important parameters in evaluating a watermarking algorithm is its capacity. Generally, watermarking capacity is expressed by bits per pixel (bpp) unit measure. But this measure does not show what the side effects would be on image quality, watermark robustness and capacity. In this paper we propose a three dimensional measure named Capacity surface which shows the effects of ca...

Watermarking is an operation to hide important information. In this paper, a new watermarking algorithm using Shearlet transform and GWO optimization algorithm as well as SVD transform is presented. The results of this paper show the improvement of robustness and transparency of the new algorithm.

Watermarking is an important copyright protection technology which generally embeds the identity information into carrier imperceptibly. Then can be extracted to prove from watermarked even after suffering various attacks. Most of existing watermarking technologies take nature images as carriers. Different natural images, document are not so rich in color and texture, thus have less redundant c...