MediaSync: Handbook on Multimedia Synchronization

This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

Study and Implementation of Watermarking Algorithms

Water Making is the process of embedding data called a watermark into a multimedia object such that watermark can be detected or extracted later to make an assertion about the object. The object may be an audio, image or video. A copy of a digital image is identical to the original. This has in many instances, led to the use of digital content with malicious intent. One way to protect multimedia data against illegal recording and retransmission is to embed a signal, called digital signature or copyright label or watermark that authenticates the owner of the data. Data hiding, schemes to embed secondary data in digital media, have made considerable progress in recent years and attracted attention from both academia and industry. Techniques have been proposed for a variety of applications, including ownership protection, authentication and access control. Imperceptibility, robustness against moderate processing such as compression, and the ability to hide many bits are the basic but rat..

Digital Watermarking for Verification of Perception-based Integrity of Audio Data

In certain application fields digital audio recordings contain sensitive content. Examples are historical archival material in public archives that preserve our cultural heritage, or digital evidence in the context of law enforcement and civil proceedings. Because of the powerful capabilities of modern editing tools for multimedia such material is vulnerable to doctoring of the content and forgery of its origin with malicious intent. Also inadvertent data modification and mistaken origin can be caused by human error. Hence, the credibility and provenience in terms of an unadulterated and genuine state of such audio content and the confidence about its origin are critical factors. To address this issue, this PhD thesis proposes a mechanism for verifying the integrity and authenticity of digital sound recordings. It is designed and implemented to be insensitive to common post-processing operations of the audio data that influence the subjective acoustic perception only marginally (if at all). Examples of such operations include lossy compression that maintains a high sound quality of the audio media, or lossless format conversions. It is the objective to avoid de facto false alarms that would be expectedly observable in standard crypto-based authentication protocols in the presence of these legitimate post-processing. For achieving this, a feasible combination of the techniques of digital watermarking and audio-specific hashing is investigated. At first, a suitable secret-key dependent audio hashing algorithm is developed. It incorporates and enhances so-called audio fingerprinting technology from the state of the art in contentbased audio identification. The presented algorithm (denoted as ”rMAC” message authentication code) allows ”perception-based” verification of integrity. This means classifying integrity breaches as such not before they become audible. As another objective, this rMAC is embedded and stored silently inside the audio media by means of audio watermarking technology. This approach allows maintaining the authentication code across the above-mentioned admissible post-processing operations and making it available for integrity verification at a later date. For this, an existent secret-key ependent audio watermarking algorithm is used and enhanced in this thesis work. To some extent, the dependency of the rMAC and of the watermarking processing from a secret key also allows authenticating the origin of a protected audio. To elaborate on this security aspect, this work also estimates the brute-force efforts of an adversary attacking this combined rMAC-watermarking approach. The experimental results show that the proposed method provides a good distinction and classification performance of authentic versus doctored audio content. It also allows the temporal localization of audible data modification within a protected audio file. The experimental evaluation finally provides recommendations about technical configuration settings of the combined watermarking-hashing approach. Beyond the main topic of perception-based data integrity and data authenticity for audio, this PhD work provides new general findings in the fields of audio fingerprinting and digital watermarking. The main contributions of this PhD were published and presented mainly at conferences about multimedia security. These publications were cited by a number of other authors and hence had some impact on their works

Recent Trends in Communication Networks

In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges

Algorithms and Architectures for Secure Embedded Multimedia Systems

Embedded multimedia systems provide real-time video support for applications in entertainment (mobile phones, internet video websites), defense (video-surveillance and tracking) and public-domain (tele-medicine, remote and distant learning, traffic monitoring and management). With the widespread deployment of such real-time embedded systems, there has been an increasing concern over the security and authentication of concerned multimedia data. While several (software) algorithms and hardware architectures have been proposed in the research literature to support multimedia security, these fail to address embedded applications whose performance specifications have tighter constraints on computational power and available hardware resources. The goals of this dissertation research are two fold: 1. To develop novel algorithms for joint video compression and encryption. The proposed algorithms reduce the computational requirements of multimedia encryption algorithms. We propose an approach that uses the compression parameters instead of compressed bitstream for video encryption. 2. Hardware acceleration of proposed algorithms over reconfigurable computing platforms such as FPGA and over VLSI circuits. We use signal processing knowledge to make the algorithms suitable for hardware optimizations and try to reduce the critical path of circuits using hardware-specific optimizations. The proposed algorithms ensures a considerable level of security for low-power embedded systems such as portable video players and surveillance cameras. These schemes have zero or little compression losses and preserve the desired properties of compressed bitstream in encrypted bitstream to ensure secure and scalable transmission of videos over heterogeneous networks. They also support indexing, search and retrieval in secure multimedia digital libraries. This property is crucial not only for police and armed forces to retrieve information about a suspect from a large video database of surveillance feeds, but extremely helpful for data centers (such as those used by youtube, aol and metacafe) in reducing the computation cost in search and retrieval of desired videos

일반화된 디리클레 사전확률을 이용한 비지도적 음원 분리 방법

학위논문 (박사)-- 서울대학교 대학원 : 융합과학기술대학원 융합과학부, 2018. 2. 이교구.Music source separation aims to extract and reconstruct individual instrument sounds that constitute a mixture sound. It has received a great deal of attention recently due to its importance in the audio signal processing. In addition to its stand-alone applications such as noise reduction and instrument-wise equalization, the source separation can directly affect the performance of the various music information retrieval algorithms when used as a pre-processing. However, conventional source separation algorithms have failed to show satisfactory performance especially without the aid of spatial or musical information about the target source. To deal with this problem, we have focused on the spectral and temporal characteristics of sounds that can be observed in the spectrogram. Spectrogram decomposition is a commonly used technique to exploit such characteristicshowever, only a few simple characteristics such as sparsity were utilizable so far because most of the characteristics were difficult to be expressed in the form of algorithms. The main goal of this thesis is to investigate the possibility of using generalized Dirichlet prior to constrain spectral/temporal bases of the spectrogram decomposition algorithms. As the generalized Dirichlet prior is not only simple but also flexible in its usage, it enables us to utilize more characteristics in the spectrogram decomposition frameworks. From harmonic-percussive sound separation to harmonic instrument sound separation, we apply the generalized Dirichlet prior to various tasks and verify its flexible usage as well as fine performance.Chapter 1 Introduction 1 1.1 Motivation 1 1.2 Task of interest 4 1.2.1 Number of channels 4 1.2.2 Utilization of side-information 5 1.3 Approach 6 1.3.1 Spectrogram decomposition with constraints 7 1.3.2 Dirichlet prior 11 1.3.3 Contribution 12 1.4 Outline of the thesis 13 Chapter 2 Theoretical background 17 2.1 Probabilistic latent component analysis 18 2.2 Non-negative matrix factorization 21 2.3 Dirichlet prior 23 2.3.1 PLCA framework 24 2.3.2 NMF framework 26 2.4 Summary 28 Chapter 3 Harmonic-Percussive Source Separation Using Harmonicity and Sparsity Constraints . . 30 3.1 Introduction 30 3.2 Proposed method 33 3.2.1 Formulation of Harmonic-Percussive Separation 33 3.2.2 Relation to Dirichlet Prior 35 3.3 Performance evaluation 37 3.3.1 Sample Problem 37 3.3.2 Qualitative Analysis 38 3.3.3 Quantitative Analysis 42 3.4 Summary 43 Chapter 4 Exploiting Continuity/Discontinuity of Basis Vectors in Spectrogram Decomposition for Harmonic-Percussive Sound Separation 46 4.1 Introduction 46 4.2 Proposed Method 51 4.2.1 Characteristics of harmonic and percussive components 51 4.2.2 Derivation of the proposed method 56 4.2.3 Algorithm interpretation 61 4.3 Performance Evaluation 62 4.3.1 Parameter setting 63 4.3.2 Toy examples 66 4.3.3 SiSEC 2015 dataset 69 4.3.4 QUASI dataset 84 4.3.5 Subjective performance evaluation 85 4.3.6 Audio demo 87 4.4 Summary 87 Chapter 5 Informed Approach to Harmonic Instrument sound Separation 89 5.1 Introduction 89 5.2 Proposed method 91 5.2.1 Excitation-filter model 92 5.2.2 Linear predictive coding 94 5.2.3 Spectrogram decomposition procedure 96 5.3 Performance evaluation 99 5.3.1 Experimental settings 99 5.3.2 Performance comparison 101 5.3.3 Envelope extraction 102 5.4 Summary 104 Chapter 6 Blind Approach to Harmonic Instrument sound Separation 105 6.1 Introduction 105 6.2 Proposed method 106 6.3 Performance evaluation 109 6.3.1 Weight optimization 109 6.3.2 Performance comparison 109 6.3.3 Effect of envelope similarity 112 6.4 Summary 114 Chapter 7 Conclusion and Future Work 115 7.1 Contributions 115 7.2 Future work 119 7.2.1 Application to multi-channel audio environment 119 7.2.2 Application to vocal separation 119 7.2.3 Application to various audio source separation tasks 120 Bibliography 121 초 록 137Docto

Introductory Computer Forensics

INTERPOL (International Police) built cybercrime programs to keep up with emerging cyber threats, and aims to coordinate and assist international operations for ?ghting crimes involving computers. Although signi?cant international efforts are being made in dealing with cybercrime and cyber-terrorism, ?nding effective, cooperative, and collaborative ways to deal with complicated cases that span multiple jurisdictions has proven dif?cult in practic

Neural Radiance Fields: Past, Present, and Future

The various aspects like modeling and interpreting 3D environments and surroundings have enticed humans to progress their research in 3D Computer Vision, Computer Graphics, and Machine Learning. An attempt made by Mildenhall et al in their paper about NeRFs (Neural Radiance Fields) led to a boom in Computer Graphics, Robotics, Computer Vision, and the possible scope of High-Resolution Low Storage Augmented Reality and Virtual Reality-based 3D models have gained traction from res with more than 1000 preprints related to NeRFs published. This paper serves as a bridge for people starting to study these fields by building on the basics of Mathematics, Geometry, Computer Vision, and Computer Graphics to the difficulties encountered in Implicit Representations at the intersection of all these disciplines. This survey provides the history of rendering, Implicit Learning, and NeRFs, the progression of research on NeRFs, and the potential applications and implications of NeRFs in today's world. In doing so, this survey categorizes all the NeRF-related research in terms of the datasets used, objective functions, applications solved, and evaluation criteria for these applications.Comment: 413 pages, 9 figures, 277 citation

Mitigating the imposition of malicious behaviour on code

If vulnerabilities in software allow to alter the behaviour of a program, traditional virus scanners do not have a chance because there is no ingress of a malicious program. Even worse, the same, potentially vulnerable software, runs on millions of computers, smart phones, and tablets out there. One program flaw allows for malicious behaviour to be imposed on millions of instances at once. This thesis presents four novel approaches that all mitigate or prevent this type of imposition of malicious behaviour on otherwise benign code. Since attacks have adapted during the writing of this thesis, the counteract techniques presented are tailored towards different stages of the still ongoing cat-and-mouse game and each technique resembles the status quo in defences at that time.Gutartige Programme, welche sich in schädliche verwandeln lassen, stellen eine größere Bedrohung dar, als Programme, die von vornherein bösartig sind. Während bösartige Programme immerhin die klare Absicht des Diebstahls oder der Manipulation von Daten haben, hat ein gutartiges Programm in aller Regel einen Nutzen für den Anwender. Wenn nun aber ein Programmierfehler dazu führen kann, plötzlich das Verhalten eines Programms zu verändern, bleibt dies von traditionellen Virenscanner völlig ungeachtet, weil diese bloß per se schädliche Programme erkennen. Hinzu kommt, dass Software oft weit ver- breitet ist und in identischer Form auf Millionen von Computern Verwendung findet – ein gefundenes Fressen, um Sicherheitslücken millionenfach auszunutzen. Bereits 1972 zeigten Forscher, dass nicht ordnungsgemäß verarbeitete Eingaben eines Programmes dessen Verhalten beliebig ändern können. Programmierfehler, wie beispielsweise das Überschreiten eines Puffers, könnten nachgelagerte Daten überschreiben. Der Morris-Wurm von 1988 zeigte, dass diese Pufferüberläufe gezielt dazu genutzt werden können das Verhalten eines Programms beliebig zu beeinflussen. Laut MITRE Common Weakness Enumeration (CWE) ist diese Art des Angriffs auch im Jahr 2015 noch immer eine der weitverbreitetsten. Diese sog. Laufzeit-Angriffe befinden sich auf Platz 2 ( “OS Command Injection”) und Platz 3 (“classic buffer overflow”) der CWE Rangliste. Sie ermöglichen Angreifern sowohl Eingaben zu steuern, Berechnungen zu verändern oder Ausgaben zu fälschen, beispielsweise mit dem Ziel Online-Banking-Transaktion zu ändern, Spam-Email-Server im Hintergrund zu installieren oder Opfer zu erpressen, indem wertvolle Dateien verschlüsselt werden. Diese Dissertation stellt vier neue Ansätze vor, welche alle auf unterschiedliche Weise bösartige Verhaltensänderungen von eigentlich gutartiger Software ver- hindern. Da auch die Angriffe während des Schreibens dieser Dissertation verbessert wurden, stellen die hier beschriebenen Lösungskandidaten einen iterativen Prozess dar, der über den zeitlichen Verlauf dieser Dissertation in einem stetigen Katz-und-Maus-Spiel stückchenweise verfeinert wurde