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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Combating rotation, dilation and translation in digital watermarking.

January 2000 (has links)
by Yeung Siu Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 59-[62]). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background --- p.4 / Chapter 2.1 --- Properties of a digital watermarking system --- p.5 / Chapter 2.2 --- Digital watermarking in still images: Spatial-domain vs Frequency- domain --- p.7 / Chapter 2.3 --- Capacity in digital watermarking --- p.8 / Chapter 3 --- A watermarking system --- p.10 / Chapter 3.1 --- Implementation of a watermarking system --- p.10 / Chapter 3.1.1 --- Embedding watermark --- p.11 / Chapter 3.1.2 --- Detecting watermark --- p.14 / Chapter 3.2 --- Robustness testing on the watermarking system --- p.18 / Chapter 3.3 --- Geometric attacks to the watermark system --- p.18 / Chapter 3.3.1 --- "The three distortions: Translation, Dilation and Rotation" --- p.19 / Chapter 3.3.2 --- The commutative property of rotation and dilation --- p.25 / Chapter 3.3.3 --- Implementation of geometric transform --- p.25 / Chapter 4 --- General Defense on Geometric Distortions --- p.28 / Chapter 4.1 --- Special designed watermark --- p.29 / Chapter 4.1.1 --- Ring-shaped watermark --- p.29 / Chapter 4.1.2 --- Phase Taylor invariance --- p.30 / Chapter 4.1.3 --- "Rotation, dilation and translation invariant watermark" --- p.31 / Chapter 4.2 --- Distortion detection --- p.34 / Chapter 4.2.1 --- Brute-force method --- p.35 / Chapter 4.2.2 --- Interactive method --- p.37 / Chapter 5 --- Specific Defense in Geometric Distortions - Phase angle com- parison --- p.43 / Chapter 5.1 --- Translation Detection --- p.44 / Chapter 5.2 --- Dilation Detection --- p.46 / Chapter 5.3 --- Rotation Detection --- p.49 / Chapter 6 --- Further work --- p.54 / Chapter 6.1 --- Large scale distortion detection --- p.54 / Chapter 6.2 --- Mixed geometric distortions --- p.55 / Chapter 7 --- Conclusion --- p.57 / Bibliography --- p.59

Theory and applications of data hiding in still images

Alturki, Faisal 05 1900 (has links)
No description available.

Establishing paper-types for manuscript dating purposes : filigranology, rastrology and their application to HR III 4 1/2 2 427 and other manuscripts from the Oettingen-Wallerstein Music Collection /

Shannon, Jacqueline Faissal. January 2000 (has links)
Thesis (D. Mus. Arts)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 104-110).

On information hiding techniques for digital images

Brisbane, Gareth Charles Beattie. January 2004 (has links)
Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 195-202.

Ευφυής διαχείριση ιατρικών δεδομένων

Σκαλκίδης, Ηλίας 28 September 2010 (has links)
Το πεδίο έρευνας της παρούσας διδακτορικής διατριβής είναι η ευφυής διαχείριση ιατρικών δεδομένων και πιο συγκεκριμένα ιατρικό βίντεο που επιτυγχάνεται κυρίως με την ενσωμάτωση κλινικών δεδομένων με τη χρήση ψηφιακής υδατογραφίας στο ιατρικό βίντεο. Η ψηφιακή υδατογραφία είναι το ερευνητικό πεδίο που ασχολείται με τη διαδικασία ενσωμάτωσης κρυφών πληροφοριών σε ένα σήμα. Η συγκεκριμένη ερευνητική εργασία επικεντρώνεται σε ένα μη ορατό και εύρωστο υδατογραφικό σχήμα για ιατρικό βίντεο. Μια συχνή απαίτηση για τα υδατογραφικά σχήματα είναι η ικανότητα τυφλής αποκωδικοποίησης, η αποκωδικοποίηση δηλαδή χωρίς το αρχικό σήμα. Στην ερευνητική εργασία σχεδιάστηκε και υλοποιήθηκε ένα υδατογραφικό σχήμα που σκοπό έχει τη χρήση του από ιατρικούς οργανισμούς για την προστασία των ιατρικών δεδομένων που παρέχουν τα ιατρικά βίντεο καθώς και την ευφυή διαχείριση των κλινικά χρήσιμων δεδομένων για διαγνωστικούς και εκπαιδευτικούς σκοπούς. Πιο συγκεκριμένα το σύστημα εφαρμόζει τρισδιάστατο μετασχηματισμό κυματιδίων σε ιατρικά βίντεο και ενσωματώνει πολλαπλά υδατογραφήματα, με διαφορετικές ανάγκες σε απαιτήσεις για ακεραιότητα και αδιορατότητα, χωρίς ωστόσο να αλλοιώνει τη διαγνωστική αξία των ιατρικών εξετάσεων. Καθώς η χρησιμότητα της εφαρμογής υδατογραφικών σχημάτων στις ιατρικές εικόνες είναι διεθνώς αναγνωρισμένη, ενώ αντίθετα δεν έχει γίνει μέχρι στιγμής καμία προσέγγιση για ιατρικά βίντεο, η παρούσα ερευνητική εργασία αποτελεί μια καινοτόμα προσέγγιση στην εισαγωγή υδατογραφίας και στα ιατρικά βίντεο, η οποία παράλληλα διαχειρίζεται ευφυώς τις κλινικές διαγνώσεις που προκύπτουν από αυτά. / The research field of this Ph.D thesis is the intelligent management of medical data, and more specifically medical video which is achieved based on the embedding of clinical data through the use of digital watermarking, on the medical video. Digital watermarking is the research field that uses a process to embed hidden information into a signal. The Ph.D thesis focuses on a non visible and robust watermarking scheme for medical videos. A common requirement of watermarking schemes is the ability to blindly decode a message without the use of the original signal. On the current work, a watermarking scheme was designed and implemented aiming to be used by medical organizations to protect medical data and to intelligent manage clinical useful data for diagnostic and educational purposes. In particular the system performs a three dimensional discrete wavelet transform into medical videos and embeds multiple watermarks with different requirements for integrity and imperceptibility without degradation of the diagnostic value of the medical examinations. The use of watermarking schemes on medical images is well established by the international literature. The use of a watermarking scheme for medical videos has not been achieved until today. The present scientific works proposes an innovative approach for medical video watermarking, that intelligently manages at the same time clinical diagnosis from the examinations.

Regaining synchronisation with watermarks and neural networks

Knoetze, Reolyn 06 June 2008 (has links)
Reliable communication is an important part of everyday living. When transmitting a message over a physical channel, noise is introduced that causes errors in the message. These errors can be inversion errors or synchronization errors. The aim of this thesis is to investigate coding techniques to minimise the effect of synchronization errors that occurred in a transmitted message. Watermarks are inserted into the encoded sequence. A neural network system is implemented before the decoder to detect the watermark and regain synchronization. / Prof. H. C. Ferreira

A watermarking protocol for digital contents distribution /

Curreem, Hanif. January 2002 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references (leaves 65-68). Also available in electronic version. Access restricted to campus users.

Electromagnetic Side-Channel Analysis for Hardware and Software Watermarking

Lakshminarasimhan, Ashwin 01 January 2011 (has links) (PDF)
With more and more ICs being used in sectors requiring confidentiality and integrity like payment systems, military, finance and health, there is a lot of concern in the security and privacy of ICs. The widespread adoption of Intellectual Property (IP) based designs for modern systems like system on chips has reduced the time to market and saved a lot of money for many companies. But this has also opened the gates for problems like product piracy, IP theft and fraud. It is estimated that billions of dollars are lost annually to illegal manufacturing of Integrated Circuits. A possible solution to this problem of IP theft is to insert small circuits which are like unique IDs that only the owner or the registered verifier will know and detect in case of any conflict. The circuits that are inserted are called watermarks and are in some cases kept very small so as to be hidden. In such cases, we would need detection schemes that work well even with very small watermarks. In this work, we use Electro-Magnetic (EM) based side-channels for the detection of watermarks. Since the 90s, Side-channel Analyses have attracted significant attention within the cryptographic community as they are able to obtain secret information from smart cards and ICs. The power side-channel analysis is a very powerful method but EM side-channels are very useful as they will not need a resistor in series to the power supply and just needs passive observation of the EM radiations emanated by the IC. This passive monitoring will be a big advantage in the case of automated watermark detection used by a verifier. In this work, we start with EM side-channel analysis on FPGA for smaller designs. We insert watermarks on a Micro-controller, Smartcard and an FPGA and detect these watermarks using EM side-channel information emanated from the Design under Test. We used environments with different levels of noise interference. We compare the watermarking application using EM side-channels and Power side-channels in these different setups. These watermarks are very small and are hard to attack or remove by an attacker through reverse engineering or side-channel information. Due to the robustness against such attacks and the easy access of EM side-channels when compared to power side-channels, the EM side-channel based watermarks will be a very good solution for the IP theft problem. EM side-channel based watermark detection supports automation which companies of IP cores can make use of. We also extended this work to EM Side-channel Trojans as the concepts are similar

Effects of soil management practices on water infiltration and maize yield to improve Mississippi River Valley Alluvial Aquifer sustainability

Rix, Jacob 09 December 2022 (has links) (PDF)
Surface sealing and hardpans in loam soils are problematic in the Mid-South U.S. because of intense tillage. Two experiments quantified the effects of soil management practices on infiltration and maize yield in loam soils. The first study measured the impacts of in-row subsoiling frequency × furrow irrigation frequency. In-row subsoiling significantly improved the infiltration of irrigation but not the infiltration of precipitation. In-row subsoiling with low irrigation frequency is optimal to achieve profitable maize yields while encouraging groundwater conservation. In the second study, six soil management treatments were imposed. For single-ring infiltrometer tests, infiltration rates were different between the two measurement dates but not between measured treatments. In 2022, neutron attenuation data indicated no differences in soil water content between measured treatments. Based on both studies, in-row subsoiling was proven to be an economically viable option in comparison to other Mississippi Delta on-farm conservation practices in the short term.

Multi-marcação de vídeo baseada em marca d'água LWT-SVD usando abordagem lateral

Fung, Charles Way Hun 12 April 2012 (has links)
CAPES / Vídeos digitais se tornaram uma forma de comunicação altamente utilizada na rede, entretanto estes dados são facilmente copiados e distribuídos. Isto se deve ao crescente número de ferramentas que surgiram com este objetivo, causando quebra dos direitos autorais e distribuição ilegal de conteúdo. A solução mais estudada para este problema são as marcas d'água digitais, que provêm segurança em forma de autenticação e verificação de violação. Neste trabalho, foi desenvolvido um novo método de inserção e extração de marcas d'água em um vídeo, usando o processo chamado abordagem lateral. Este possibilita a marcação em blocos de frames. As diversas marcas inseridas são usadas como redundância para aumentar a robustez contra ataques. Os testes realizados seguiram o padrão dos benchmarks Vidmark e Stirmark, os quais demonstram a eficiência do método em manter a marca d'água mesmo após ataques. / Digital videos have become the most used way to communicate, however these data are easily copied and distributed. That happen due the growing number of tools that are create with this goal, causing breach of copyright and illegal distribution of content. The most studied solution that can solve this problem are the digital watermarks that provide security like authentication and tamper detection. In this work, we developed a new method of embedding and extracting watermarks in a video using a process called side view. This process allows watermark a block of frames. The several watermarks embedded can be used like redundance to grow the robustness of the method against attacks. The tests followed the standard benchmarks Vidmark and Stirmark that show the performance of the method in keep the watermark even after attacks.

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