Digital watermarking and novel security devices

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Framing digital image credibility: image manipulation problems, perceptions and solutions

Image manipulation is subverting the credibility of photographs as a whole. Currently there is no practical solution for asserting the authenticity of a photograph. People express their concern about this when asked but continue to operate in a ‘business as usual’ fashion. While a range of digital forensic technologies has been developed to address falsification of digital photographs, such technologies begin with ‘sourceless’ images and conclude with results in equivocal terms of probability, while not addressing the meaning and content contained within the image. It is interesting that there is extensive research into computer-based image forgery detection, but very little research into how we as humans perceive, or fail to perceive, these forgeries when we view them. The survey, eye-gaze tracking experiments and neural network analysis undertaken in this research contribute to this limited pool of knowledge. The research described in this thesis investigates human perceptions of images that are manipulated and, by comparison, images that are not manipulated. The data collected, and their analyses, demonstrate that humans are poor at identifying that an image has been manipulated. I consider some of the implications of digital image manipulation, explore current approaches to image credibility, and present a potential digital image authentication framework that uses technology and tools that exploit social factors such as reputation and trust to create a framework for technologically packaging/wrapping images with social assertions of authenticity, and surfaced metadata information. The thesis is organised into 6 chapters. Chapter 1: Introduction I briefly introduce the history of photography, highlighting its importance as reportage, and discuss how it has changed from its introduction in the early 19th century to today. I discuss photo manipulation and consider how it has changed along with photography. I describe the relevant literature on the subject of image authentication and the use of eye gaze tracking and neural nets in identifying the role of human vision in image manipulation detection, and I describe my area of research within this context. Chapter 2: Literature review I describe the various types of image manipulation, giving examples, and then canvas the literature to describe the landscape of image manipulation problems and extant solutions, namely: • the nature of image manipulation, • investigations of human perceptions of image manipulation, • eye gaze tracking and manipulated images, • known efforts to create solutions to the problem of preserving unadulterated photographic representations and the meanings they hold. Finally, I position my research activities within the context of the literature. Chapter 3: The research I describe the survey and experiments I undertook to investigate attitudes toward image manipulation, research human perceptions of manipulated and unmanipulated images, and to trial elements of a new wrapper-style file format that I call .msci (mobile self-contained image), designed to address image authenticity issues. Methods, results and discussion for each element are presented in both explanatory text and by presentation of papers resulting from the experiments. Chapter 4: Analysis of eye gaze data using classification neural networks I describe pattern classifying neural network analysis applied to selected data obtained from the experiments and the insights this analysis provided into the opaque realm of cognitive perception as seen through the lens of eye gaze. Chapter 5: Discussion I synthesise and discuss the outcomes of the survey and experiments. I discuss the outcomes of this research, and consider the need for a distinction between photographs and photo art. I offer a theoretical formula within which the overall authenticity of an image can be assessed. In addition I present a potential image authentication framework built around the .msci file format, designed in consideration of my investigation of the requirements of the image manipulation problem space and the experimental work undertaken in this research. Chapter 6: Conclusions and future work This thesis concludes with a summary of the outcomes of my research, and I consider the need for future experimentation to expand on the insights gained to date. I also note some ways forward to develop an image authentication framework to address the ongoing problem of image authenticity

From Grain to Pixel

Film is in a state of rapid change, with the transition from analog to digital profoundly affecting not just filmmaking and distribution, but also the theoretical conceptualization of the medium film and the practice of film archiving. New forms of digital archives are being developed that make use of participatory media to provide a more open form of access than any traditional archive has offered before. Film archives are thus faced with new questions and challenges. From Grain to Pixel attempts to bridge the fields of film archiving and academic research, by addressing the discourse on film ontology and analysing how it affects the role of film archives. Fossati proposes a new theoretization of film archival practice as the starting point for a renewed dialogue between film scholars and film archivists.Het bewegende beeld bevindt zich in een overgangsperiode waarin analoge (fotochemische) film geleidelijk vervangen wordt door digitale film. Deze overgang heeft niet alleen diepgaande invloed op filmproductie en -distributie, maar ook op de manier van archiveren van film en de theoretische conceptualisering van dit medium. Van digitale archieven worden steeds nieuwe vormen ontwikkeld. Deze archieven - digitale filmdatabases en YouTube bijvoorbeeld - maken gebruik van media die participatie van vele gebruikers mogelijk maken en worden zo toegankelijker dan ooit. Ondertussen is er nog onvoldoende dialoog tussen archivarissen en filmwetenschappers. From Grain to Pixel slaat een brug tussen archiveringspraktijken en wetenschappelijk onderzoek dat gebaseerd is op relevante debatten in film- en nieuwe mediastudies. Fossati stelt een nieuwe theorie op voor het archiveren en restaureren van film. Dit biedt mogelijkheden voor een hernieuwde dialoog tussen archivarissen en wetenschappers

To Affinity and Beyond: Interactive Digital Humans as a Human Computer Interface

The field of human computer interaction is increasingly exploring the use of more natural, human-like user interfaces to build intelligent agents to aid in everyday life. This is coupled with a move to people using ever more realistic avatars to represent themselves in their digital lives. As the ability to produce emotionally engaging digital human representations is only just now becoming technically possible, there is little research into how to approach such tasks. This is due to both technical complexity and operational implementation cost. This is now changing as we are at a nexus point with new approaches, faster graphics processing and enabling new technologies in machine learning and computer vision becoming available. I articulate the issues required for such digital humans to be considered successfully located on the other side of the phenomenon known as the Uncanny Valley. My results show that a complex mix of perceived and contextual aspects affect the sense making on digital humans and highlights previously undocumented effects of interactivity on the affinity. Users are willing to accept digital humans as a new form of user interface and they react to them emotionally in previously unanticipated ways. My research shows that it is possible to build an effective interactive digital human that crosses the Uncanny Valley. I directly explore what is required to build a visually realistic digital human as a primary research question and I explore if such a realistic face provides sufficient benefit to justify the challenges involved in building it. I conducted a Delphi study to inform the research approaches and then produced a complex digital human character based on these insights. This interactive and realistic digital human avatar represents a major technical undertaking involving multiple teams around the world. Finally, I explored a framework for examining the ethical implications and signpost future research areas

From Grain to Pixel

"In From Grain to Pixel , Giovanna Fossati analyzes the transition from analog to digital film and its profound effects on filmmaking and film archiving. Reflecting on the theoretical conceptualization of the medium itself, Fossati poses significant questions about the status of physical film and the practice of its archival preservation, restoration and presentation. From Grain to Pixel attempts to bridge the fields of film archiving and academic research by addressing the discourse on film's ontology and analyzing how different interpretations of what film is affect the role and practices of film archives. Ultimately, Fossati proposes a novel theorization of film archival practice as the starting point for a renewed dialogue between film scholars and film archivists. Almost a decade after its first publication, this updated edition covers the latest developments in the field. Besides a new general introduction, a new conclusion and extensive updates to each chapter, a novel theoretical framework and a new case study have been added. Giovanna Fossati is chief curator at EYE Filmmuseum and professor of film heritage and digital film culture at the University of Amsterdam.

From Grain to Pixel

Film is in a state of rapid change, with the transition from analog to digital profoundly affecting not just filmmaking and distribution, but also the theoretical conceptualization of the medium film and the practice of film archiving. New forms of digital archives are being developed that make use of participatory media to provide a more open form of access than any traditional archive has offered before. Film archives are thus faced with new questions and challenges. From Grain to Pixel attempts to bridge the fields of film archiving and academic research, by addressing the discourse on film ontology and analysing how it affects the role of film archives. Fossati proposes a new theoretization of film archival practice as the starting point for a renewed dialogue between film scholars and film archivists

Advances in Computer Recognition, Image Processing and Communications, Selected Papers from CORES 2021 and IP&C 2021

As almost all human activities have been moved online due to the pandemic, novel robust and efficient approaches and further research have been in higher demand in the field of computer science and telecommunication. Therefore, this (reprint) book contains 13 high-quality papers presenting advancements in theoretical and practical aspects of computer recognition, pattern recognition, image processing and machine learning (shallow and deep), including, in particular, novel implementations of these techniques in the areas of modern telecommunications and cybersecurity