Suchergebnisse

<p>As creative works (e.g. books, films, music, photographs) become increasingly available in digital formats in a highly connected world, it also becomes increasingly difficult to secure intellectual property rights. Digital watermarking is one potential technology to aid intellectual property owners in controlling and tracking the use of their works. Surveys the state of digital watermarking research and examines the attacks that the technology faces and how it fares against them. Digital watermarking is an inherently difficult design problem subject to many constraints. The technology currently faces an uphill battle to be secure against relatively simple attacks.</p><p><strong>Defence Science Journal, 2011, 61(5), pp.408-414</strong><strong><strong>, DOI:http://dx.doi.org/10.14429/dsj.61.1176</strong></strong></p>

One common drawback of virtually all current data embedding methods is the fact that the original image is inevitably distorted due to data embedding itself. This distortion typically cannot be removed completely due to quantization, bit-replacement, or truncation at the grayscales 0 and 255. Although the distortion is often quite small and perceptual models are used to minimize its visibility, the distortion may not be acceptable for medical imagery (for legal reasons) or for military images inspected under nonstandard viewing conditions (after enhancement or extreme zoom). In this paper, we introduce a new paradigm for data embedding in images (lossless data embedding) that has the property that the distortion due to embedding can be completely removed from the watermarked image after the embedded data has been extracted. We present lossless embedding methods for the uncompressed formats (BMP, TIFF) and for the JPEG format. We also show how the concept of lossless data embedding can be used as a powerful tool to achieve a variety of nontrivial tasks, including lossless authentication using fragile watermarks, steganalysis of LSB embedding, and distortion-free robust watermarking.

The use of multimedia technology is growing every day, and it is difficult and time-consuming to provide allowed data while preventing secret information from being used without authorization. The material that has been watermarked can only be accessed by authorized users. Digital watermarking is a popular method for protecting digital data. The embedding of secret data into actual information is the subject of digital watermarking. This paper examines watermarking techniques, methodologies, and attacks, as well as the development of watermarking digital images stored in both the spatial and frequency domains.

Technology advancement has facilitated digital content, such as images, being acquired in large volumes. However, requirement from the privacy or legislation perspective still demands the need for intellectual content protection. In this paper, we propose a deep neural network (DNN) based watermarking method to achieve this goal. Instead of training a neural network for protecting a specific image, we train the network on an image dataset and generalize the trained model to protect distinct test images in a bulk manner. Respective evaluations from both the subjective and objective aspects confirm the generality and practicality of our proposed method. To demonstrate the robustness of this general neural watermarking approach, commonly used attacks are applied to the watermarked images to examine the corresponding extracted watermarks, which still retain sufficient recognizable traits for some occasions. Testing on distinctive dataset shows the satisfying generalization of our proposed method, and practice such as loss function adjustment can cater to the capacity requirement of complicated watermark. We also discuss some traits of the trained model, which incur the vulnerability to JPEG compression attack. However, remedy seeking for this can potentially open a window to understand the underlying working principle of DNN in future work. Considering its performance and economy, it is concluded that subsequent studies that generalize our work on utilizing DNN for intellectual content protection might be a promising research trend.

Watermarks. The term evokes visions of shady characters secretly beavering away in dark basements surrounded by forged $100 bills drying on clothes lines. In a digital media context, away from the traditional world of inks and paper, the same old problem remains but it relates not just to forgery but also to outright theft, because one digital copy can spawn millions of others with the single click of a mouse button. It is hardly surprising that the notion of a digital watermark has stimulated avid interest amongst artists and publishers alike. It is commonly recognized that digital watermarks must be as robust as the media in which they are embedded. For example, a rotated, cropped, and rescanned water-marked image should still be a watermarked image. However, this robustness requirement directly conflicts with the need for a digital watermark to be unobtrusive. The most effective techniques used to embed watermarks are the result of a combination of secret key-based techniques used for military communication and simple models of the human visual system. The most familiar application for digital watermarks is for copyright protection and protection of intellectual property. On its own, a watermark does not provide any legal proof of ownership. In other words, the use of a given digital watermark to protect intellectual property must be registered with a trusted third party to be of any value. Any technique for embedding robust digital watermarks must be compatible with methods for registering copyright. A watermark's resistance to intentional and unintentional degradation has been the main subject of interest in the watermarking community. The main challenges are geometric transformations such as change of proportion or simple rescaling. One watermark removal technique that is supplied on the Internet simply shifts a corner of the image. Lossy image compression such as JPEG and filtering are more easily overcome and, generally speaking, watermarks have evolved into very resistant forms. The laboratory, but will they really work in the real world?

International audience ; The amount of digital visual data (image, video and 3D object) has increased rapidly on the Internet. Image, video and 3D object security becomes increasingly important for many applications, e.g., confidential transmission, video surveillance, military and medical applications. For example, the necessity of fast and secure diagnosis is vital in the medical world. Nowadays, the transmission of visual data is a daily routine and it is necessary to find an efficient way to transmit them over networks. Two main groups of technologies have been developed for this purpose. The first one is based on content protection through encryption. In this group, proper decryption of data requires a key. The second group bases the protection on digital watermarking or data hiding, aimed at secretly embedding a message into the data. In order to not increase the processing time, these two approaches must be combined with the compression stage. Nowadays, the challenge is to perform simultaneously for example image encryption and compression.

International audience ; The amount of digital visual data (image, video and 3D object) has increased rapidly on the Internet. Image, video and 3D object security becomes increasingly important for many applications, e.g., confidential transmission, video surveillance, military and medical applications. For example, the necessity of fast and secure diagnosis is vital in the medical world. Nowadays, the transmission of visual data is a daily routine and it is necessary to find an efficient way to transmit them over networks. Two main groups of technologies have been developed for this purpose. The first one is based on content protection through encryption. In this group, proper decryption of data requires a key. The second group bases the protection on digital watermarking or data hiding, aimed at secretly embedding a message into the data. In order to not increase the processing time, these two approaches must be combined with the compression stage. Nowadays, the challenge is to perform simultaneously for example image encryption and compression.

International audience ; The amount of digital visual data (image, video and 3D object) has increased rapidly on the Internet. Image, video and 3D object security becomes increasingly important for many applications, e.g., confidential transmission, video surveillance, military and medical applications. For example, the necessity of fast and secure diagnosis is vital in the medical world. Nowadays, the transmission of visual data is a daily routine and it is necessary to find an efficient way to transmit them over networks. Two main groups of technologies have been developed for this purpose. The first one is based on content protection through encryption. In this group, proper decryption of data requires a key. The second group bases the protection on digital watermarking or data hiding, aimed at secretly embedding a message into the data. In order to not increase the processing time, these two approaches must be combined with the compression stage. Nowadays, the challenge is to perform simultaneously for example image encryption and compression.

In the last decade, 3D models gained interest in many applications, such as games, the medical field, and manufacture. It is necessary to protect these models from unauthorized copying, distribution, and editing. Digital watermarking is the best way to solve this problem. This paper introduces a robust watermarking method by embedding the watermark in the low-frequency domain, then selecting the coarsest level for embedding the watermark based on the strength factor. The invisibility of the watermark for the proposed algorithm is tested by using different measurements, such as HD and PSNR. The robustness was tested by using different types of attacks; the correlation coefficient was applied for the evaluation of the extracted watermark. From the results, it is clear that the proposed algorithm achieved good invisibility and robustness against the geometrical attack and the added noise.

The major growth of information technology is based on the growth of computer networks. The computer network diminished the entire global in a nutshell, via the internet and the intranet capabilities. In the recent year, communicating information within authenticated groups in the text, image and video formats are highly unavoidable one. And in the same manner, there are more possibility that the communicated information to be hacked by the anonymous hacker. The hacker may be passive or active; it is highly risk for many engineering applications like military network. Hence, digital watermarking is merged to rectify the above pitfalls. Watermarking techniques developed for images are mainly classified into visible and invisible approaches. The study further analyses the modern digital watermarking system.Key words: Providing additional information, Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT), Discrete Fourier Transform (DFT), Peak Signal to Noise Ratio (PSNR), sliding square window containing