Fast compressed domain watermarking of MPEG multiplexed streams

In this paper, a new technique for watermarking of MPEG compressed video streams is proposed. The watermarking scheme operates directly in the domain of MPEG multiplexed streams. Perceptual models are used during the embedding process in order to preserve the quality of the video. The watermark is embedded in the compressed domain and is detected without the use of the original video sequence. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. The resulting watermarking system is very fast and reliable, and is suitable for copyright protection and real-time content authentication applications

Fast watermarking of MPEG-1/2 streams using compressed-domain perceptual embedding and a generalized correlator detector

A novel technique is proposed for watermarking of MPEG-1 and MPEG-2 compressed video streams. The proposed scheme is applied directly in the domain of MPEG-1 system streams and MPEG-2 program streams (multiplexed streams). Perceptual models are used during the embedding process in order to avoid degradation of the video quality. The watermark is detected without the use of the original video sequence. A modified correlation-based detector is introduced that applies nonlinear preprocessing before correlation. Experimental evaluation demonstrates that the proposed scheme is able to withstand several common attacks. The resulting watermarking system is very fast and therefore suitable for copyright protection of compressed video

Η επίδραση της κλιματικής αλλαγής και ο κοινωνικός ρόλος των Ενόπλων Δυνάμεων κατά τη διαχείριση κρίσεων και καταστροφών

Στη σύγχρονη εποχή, έχει γίνει ευρέως αποδεκτό ότι διανύουμε μια περίοδο απότομης μεταβολής των κλιματικών δεδομένων και όλα τα κράτη στον πλανήτη επηρεάζονται σε μικρό ή μεγάλο βαθμό. Η κλιματική αλλαγή, που ήδη επιδρά σε σημαντικούς τομείς της κοινωνίας μας, επηρεάζει με σύνθετους τρόπους τις ήδη υπάρχουσες επικινδυνότητες, δηλαδή την πιθανότητα εκδήλωσης, την ένταση, το μέγεθος και τη συχνότητα των φαινομένων (σεισμοί, πυρκαγιές, πλημύρες, ακραία καιρικά φαινόμενα, επιδημίες κλπ) που μπορεί να οδηγήσουν σε καταστροφές. Η διεθνής επιστημονική κοινότητα βρίσκεται σε συνεχή επαγρύπνηση καθώς διακυβεύεται η ασφάλεια και η κοινωνική σταθερότητα στον πλανήτη μας. Οι επιστήμονες χρησιμοποιούν παρατηρήσεις από το έδαφος, τον αέρα και το διάστημα, μαζί με θεωρητικά μοντέλα, για να παρακολουθήσουν και να μελετήσουν την κλιματική αλλαγή στο παρελθόν, το παρόν και το μέλλον σε μια προσπάθεια εξαγωγής εκτιμήσεων και λήψης αποφάσεων σχετικά με την εφαρμογή μέτρων μετριασμού των συνεπειών της ραγδαίας κλιματικής μεταβολής. Τα αρχεία δεδομένων για το κλίμα παρέχουν ενδείξεις βασικών δεικτών της κλιματικής αλλαγής που αντικατοπτρίζουν τις επιπτώσεις της στον πλανήτη. Η παρούσα διατριβή, μέσα από τη μελέτη της διαθέσιμης βιβλιογραφίας, επιχειρεί να αποτυπώσει την επίδραση της κλιματικής αλλαγής στις επικινδυνότητες που απειλούν την ανθρώπινη εξέλιξη. Στο ίδιο πλαίσιο και ειδικά για την Ελλάδα, που βρίσκεται σε ξεχωριστό και ευμετάβλητο περιβάλλον, θα αξιολογηθούν οι σοβαρότεροι κίνδυνοι που αναμένεται να αντιμετωπιστούν υπό το πρίσμα της κλιματικής μεταβολής. Περαιτέρω θα αναζητηθεί η επίδραση της κλιματικής αλλαγής στον σοβαρό κοινωνικό ρόλο που διαδραματίζουν οι ένοπλες δυνάμεις κατά τη διαχείριση κρίσεων και καταστροφών, ενώ θα επισημανθεί η ανάγκη για ανθεκτικότητα και προσαρμοστικότητα στα συνεχώς μεταβαλλόμενα κλιματικά δεδομένα.In modern times, it has become widely accepted that we are going through a period of abrupt changes in climate data and all states on the planet are affected to a greater or lesser extent. Climate change, which is already affecting important sectors of our society, affects in complex ways the already existing hazards, i.e. the probability of occurrence, the intensity, magnitude and frequency of phenomena (earthquakes, fires, floods, extreme weather events, epidemics, etc.) that can lead to disasters. The international scientific community is on constant alert, as security and social stability on our planet are at stake. Scientists use observations from soil, air and space, along with theoretical models, to monitor and study climate change in the past, present and future in an effort to extract estimates and make decisions on the implementation of mitigation measures for rapid climate change. Climate data files provide evidence of key indicators of climate change that reflect its impact on the planet. The present thesis, through the study of the available bibliography, attempts to capture the impact of climate change on the hazards that threaten human evolution. In the same context and especially for Greece, which is located in a separate and volatile environment, the most serious risks that are expected to be addressed in the light of climate change will be assessed. Furthermore, the impact of climate change on the serious social role played by the armed forces in crisis and disaster management will be sought, while the need for resilience and adaptability to ever-changing climate conditions will be highlighted

Protection techniques and watermarking applications for image and video

In the present thesis, protection techniques and watermarking applications for image and video are studied. In particular, initially a new watermarking method is presented, which is suitable for copyright protection in digital images that have undergone geometric attacks. The proposed method is based on generalized Radon transformations and is especially robust to scaling and rotation attacks. Additionally, a fast video watermarking system that operates in the compressed domain and is suitable for multiplexed MPEG- 1/2 video is described. The proposed system detects the watermark using a generalized correlator detector that performs a non-linear preprocessing of the data before detection and outperforms the classic correlator in terms of detection performance. A complete video security system is also proposed, which combines cryptography and watermarking for the secure delivery of MPEG video in CD and DVD. Finally, information embedding in images that are coded using the JPEG2000 coding standard is studied

Rotation, Translation and Scaling Invariant Watermarking Using a Generalized Radon Transformation

this paper. The watermark embedding and detection are performed in a domain which is invariant to geometric attacks such as rotation, scaling and translation. The invariant domain is derived by applying a new generalized Radon transform to the image. The ability of the proposed method to withstand geometric attacks is evaluated experimentall

Digital watermarking for the copyright protection of compressed video

In this chapter, a new technique for the watermarking of MPEG-1 and MPEG-2 compressed video streams is proposed. The watermarking scheme operates directly in the domain of MPEG-1 system streams and MPEG-2 program streams (multiplexed streams). Perceptual models are used during the embedding process in order to preserve video quality. The watermark is embedded in the compressed domain and is detected without the use of the original video sequence. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. The resulting watermarking system is very fast and reliable, and is suitable for the copyright protection of video content