92 research outputs found

    Entropy Based Robust Watermarking Algorithm

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    Tänu aina kasvavale multimeedia andmeedastus mahtudele Internetis, on esile kerkinud mured turvalisusest ja piraatlusest. Digitaalse meedia paljundamise ja muutmise maht on loonud vajaduse digitaalse meedia vesimärgistamise järgi. Selles töös on tutvustatud vastupidavaid vesimärkide lisamise algoritme, mis lisavad vesimärgid madala entroopiaga pildi osadesse. Välja pakutud algoritmides jagatakse algne pilt blokkidesse ning arvutatakse iga bloki entroopia. Kõikide blokkide keskmine entroopia väärtus valitakse künniseks, mille järgi otsustatakse, millistesse blokkidesse vesimärk lisada. Kõik blokid, mille entroopia on väiksem kui künnis, viiakse signaali sageduse kujule kasutades Discrete Wavelet Transform algoritmi. Madala sagedusega sagedusvahemikule rakendatakse Chirp Z-Transform algoritmi ja saadud tulemusele LU-dekompositsiooni või QR-dekompositsiooni. Singular Value Decomposition meetodi rakendamisel diagonaalmaatriksile, mis saadi eelmisest sammust, saadakse iga bloki vastav väärtus. Vesimärk lisatakse pildile, liites iga bloki arvutatud väärtusele vesimärgi Singular Value Decomposition meetodi tulemused. Kirjeldatud algoritme testiti ning võrreldi teiste tavapärast ning uudsete vesimärkide lisamise tehnoloogiatega. Kvantitatiivsed ja kvalitatiivsed eksperimendid näitavad, et välja pakutud meetodid on tajumatud ning vastupidavad signaali töötlemise rünnakutele.With growth of digital media distributed over the Internet, concerns about security and piracy have emerged. The amount of digital media reproduction and tampering has brought a need for content watermarking. In this work, multiple robust watermarking algorithms are introduced. They embed watermark image into singular values of host image’s blocks with low entropy values. In proposed algorithms, host image is divided into blocks, and the entropy of each block is calculated. The average of all entropies indicates the chosen threshold value for selecting the blocks in which watermark image should be embedded. All blocks with entropy lower than the calculated threshold are decomposed into frequency subbands using discrete wavelet transform (DWT). Subsequently chirp z-transform (CZT) is applied to the low-frequency subband followed by an appropriate matrix decomposition such as lower and upper decomposition (LUD) or orthogonal-triangular decomposition (QR decomposition). By applying singular value decomposition (SVD) to diagonal matrices obtained by the aforementioned matrix decompositions, the singular values of each block are calculated. Watermark image is embedded by adding singular values of the watermark image to singular values of the low entropy blocks. Proposed algorithms are tested on many host and watermark images, and they are compared with conventional and other state-of-the-art watermarking techniques. The quantitative and qualitative experimental results are indicating that the proposed algorithms are imperceptible and robust against many signal processing attacks

    An Invisible Logo Watermarking Using Arnold Transform

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    AbstractDigital watermarking is the process of hiding information into the digital content. The method of embedding a smaller logo image into the host image is called logo watermarking. The system proposes an invisible and secure watermarking. The key entered initially determine the location of embedding and thus classified the host image to white and black textured regions. The logo image is then transformed using Arnold transform. Discrete Wavelet Transform (DWT) technique is employed for embedding the transformed logo into the white textured regions. Watermark extraction is done by entering the same key which was already entered during embedding. The system is secure and the logo is imperceptible within the host image. Finally for analysis, PSNR value has been used as a metric for determining the quality of the recovered image

    A novel QR-code based watermarking scheme for digital rights

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    This paper presents a digital rights protection scheme for both colour and grayscale images using a novel approach that combines watermarking and cryptography. The schema involves two parties: the owner of the digital rights and a generic user who acquired some rights on a copy of the image that will be watermarked. The watermark, a QR code derived from a signed “License Agreement”, is repeatedly inserted, and scrambled, by the image right’s owner, into the frequency components of the image, thus producing the watermarked image. The schema, a non-blind type, achieves good perceptive quality and fair robustness using the 3rd level of the Discrete Wavelet Transform. The experimental results show that, inserting more occurrences of a scrambled QR code, the proposed algorithm is quite resistant to JPEG compression, rotation, cropping and salt & peeper noise

    Optimized DWT Based Digital Image Watermarking and Extraction Using RNN-LSTM

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    The rapid growth of Internet and the fast emergence of multi-media applications over the past decades have led to new problems such as illegal copying, digital plagiarism, distribution and use of copyrighted digital data. Watermarking digital data for copyright protection is a current need of the community. For embedding watermarks, robust algorithms in die media will resolve copyright infringements. Therefore, to enhance the robustness, optimization techniques and deep neural network concepts are utilized. In this paper, the optimized Discrete Wavelet Transform (DWT) is utilized for embedding the watermark. The optimization algorithm is a combination of Simulated Annealing (SA) and Tunicate Swarm Algorithm (TSA). After performing the embedding process, the extraction is processed by deep neural network concept of Recurrent Neural Network based Long Short-Term Memory (RNN-LSTM). From the extraction process, the original image is obtained by this RNN-LSTM method. The experimental set up is carried out in the MATLAB platform. The performance metrics of PSNR, NC and SSIM are determined and compared with existing optimization and machine learning approaches. The results are achieved under various attacks to show the robustness of the proposed work

    Protection and authentication of Dubai digital elevation model using hybrid watermarking technique

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    Nowadays, with the availability of digital images and models at no cost on the World Wide Web, the need to provide copyright protection of multimedia data arises. Hence, digital watermarking products have been in high demand. Digital watermarking essentially embeds information into data in such a way that data usage is not affected, and it simultaneously protects and authenticates the data. This research paper deals with the development and evaluation of a watermarking technique for protection and authentication of Dubai Digital Elevation Model (DEM) provided by United States Geological Survey (USGS). The technique uses a hybrid combination of Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT), and it is implemented for the protection of DEM by embedding the ownership information in hybrid DCT-DWT domain and for checking the integrity of the elevation model by embedding hash-key information in the spatial domain. The proposed watermarking technique causes minimal distortion to the DEM and the performance is assessed by using Peak Singal-to-Noise Ratio (PSNR), Wavelet Signal-to-Noise Ratio (WSNR), and Structural Similarity Index Measurement (SSIM). The results show promising performance with strong robustness of watermark information ownership for many intentional and non-intentional attacks, in addition to precise detection of localized modified areas on tampered DEM

    Digital Image Watermarking Algorithm Using the Intermediate Frequency

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    Digital image watermarking is one of the proposed solutions for copyright protection of multimedia data. This technique is better than Digital Signatures and other methods because it does not increase overhead. Watermarking adds the additional requirement of robustness. To improve the robustness of digital image watermarking method based on the image frequency, this paper adopts the intermediate frequency to embed the watermarking and proposes an digital image watermarking algorithm based on robust principal component analysis (RPCA) and discrete cosine transform (DCT). Firstly, the high frequency part and the low frequency part of the image are extracted by the RPCA algorithm. Because the high frequency part has complex statistical characteristics, this paper processes the high frequency part with "8×8" DCT method to obtain intermediate frequency coefficients and then the watermarking information is embedded into the obtained intermediate frequency coefficients. The experimental results show that the proposed algorithm leads to satisfactory robustness to the attacks of impulse noise and cropping

    AN INVESTIGATION OF DIFFERENT VIDEO WATERMARKING TECHNIQUES

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    Watermarking is an advanced technology that identifies to solve the problem of illegal manipulation and distribution of digital data. It is the art of hiding the copyright information into host such that the embedded data is imperceptible. The covers in the forms of digital multimedia object, namely image, audio and video. The extensive literature collected related to the performance improvement of video watermarking techniques is critically reviewed and presented in this paper. Also, comprehensive review of the literature on the evolution of various video watermarking techniques to achieve robustness and to maintain the quality of watermarked video sequences

    New watermarking methods for digital images.

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    The phenomenal spread of the Internet places an enormous demand on content-ownership-validation. In this thesis, four new image-watermarking methods are presented. One method is based on discrete-wavelet-transformation (DWT) only while the rest are based on DWT and singular-value-decomposition (SVD) ensemble. The main target for this thesis is to reach a new blind-watermarking-method. Method IV presents such watermark using QR-codes. The use of QR-codes in watermarking is novel. The choice of such application is based on the fact that QR-Codes have errors self-correction-capability of 5% or higher which satisfies the nature of digital-image-processing. Results show that the proposed-methods introduced minimal distortion to the watermarked images as compared to other methods and are robust against JPEG, resizing and other attacks. Moreover, watermarking-method-II provides a solution to the detection of false watermark in the literature. Finally, method IV presents a new QR-code guided watermarking-approach that can be used as a steganography as well. --Leaf ii.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b183575

    DWT and QR code based watermarking for document DRM

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    Questo articolo presenta uno schema per la protezione dei diritti digitali per ogni tipo di documento presentato come immagine, usando passi che usano la crittografia e il watermarking. Le entità coinvolte in questo processo sono due: il proprietario del documento che ne possiede i diritti digitali e un utente generico che può scaricare o vedere una versione con watermark del documento originale. La versione con watermark contiene un codice QR che è inserito ripetutamente, e criptato, dal proprietario dei diritti sul documento, nelle componenti in frequenza dell'immagine, così producendo l'immagine con watermark. Il codice QR contiene un identificativo firmato che univocamente identifica ogni utente che usa il sistema. Lo schema, di tipo non-cieco, raggiunge una buona qualità percettiva e una discreta robustezza usando il terzo livello della Trasformata Discreta basata su Wavelet. I risultati sperimentali mostrano che tramite l'inserzione di diverse occorrenze di un codice QR criptato otteniamo un approccio che è piuttosto resistente alla compressione JPEG, alla rotazione, al ritaglio, e al rumore sale e pepe.This paper presents a digital rights protection scheme for every type of document presented as an image, by using steps that use cryptography and watermarking. The entities involved in this process are two: the owner of the document that owns its digital rights and a generic user who can download or view a watermarked version of the original document. The watermarked version contains a QR code that is repeatedly inserted, and scrambled, by the document rights owner, into the frequency components of the image, thus producing the watermarked image. The QR code contains a signed ID that uniquely identifies every users using the system. The schema, a non-blind type, achieves good perceptive quality and fair robustness using the third level of the Discrete Wavelet Transform. The experimental results show that by inserting several occurrences of a scrambled QR code we get an approach that is quite resistant to JPEG compression, rotation, cropping, and salt and pepper noise
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