Video Activism and the Ambiguities of Counter-Surveillance

This paper examines the use of visual technologies by political activists in protest situations to monitor police conduct. Using interview data with Australian video activists, this paper seeks to understand the motivations, techniques and outcomes of video activism, and its relationship to counter-surveillance and police accountability. Our data also indicated that there have been significant transformations in the organization and deployment of counter-surveillance methods since 2000, when there were large-scale protests against the World Economic Forum meeting in Melbourne accompanied by a coordinated campaign that sought to document police misconduct. The paper identifies and examines two inter-related aspects of this: the act of filming and the process of dissemination of this footage. It is noted that technological changes over the last decade have led to a proliferation of visual recording technologies, particularly mobile phone cameras, which have stimulated a corresponding proliferation of images. Analogous innovations in internet communications have stimulated a coterminous proliferation of potential outlets for images Video footage provides activists with a valuable tool for safety and publicity. Nevertheless, we argue, video activism can have unintended consequences, including exposure to legal risks and the amplification of official surveillance. Activists are also often unable to control the political effects of their footage or the purposes to which it is used. We conclude by assessing the impact that transformations in both protest organization and media technologies might have for counter-surveillance techniques based on visual surveillance.

Promoting multicultural education in the primary classroom:Broadband videoconferencing facilities and digital video

The aim of this study was to explore the impact of interaction (through gathering local field data and engaging in remote reciprocal presentations) on aspects of multicultural awareness. Sixty-six 11-12-year-old Scottish primary school pupils collected data in the field from their local community through questionnaires, interviews, direct observation, digital images and video. From this they distilled a multimedia presentation, delivered by videoconference to a partner school in the USA, who reciprocated. There was some evidence of pre-post project gains in the complexity of the children's perceptions of their community environment, the ethnicity of their community, their own ethnicity, and news images. The children's use of language to define ethnicity also became more complex and their attitudes toward ethnic minorities became more inclusive. The implications for practice, policy and future research were explored. © 2004 Elsevier Ltd. All rights reserved.

Using Digital Photography and Video in Participant Observation of Contentious Events

In this article, we discuss our experiences of using photography and video while observing contentious parades and protests in Belfast. We show how our use of these methods drew us into a series of unplanned for non-verbal interactions with other event participants who were also freely and abundantly using photographic and filming equipment to capture their own images. This interactive use of photography and video affected us emotionally and influenced what we noticed and what we omitted in our observations. In particular, it forced us to reflect upon and question our role as researchers in the events we observed and in the changing balance of power between researchers and researched.

“Signal, image and video processing” special issue: Semantic representations for social behavior analysis in video surveillance systems

No abstract available

Optimizing geometric accuracy of four dimensional CT scans acquired using the wall and couch mounted Varian Real-Time Position Management camera systems

Objective:

The aim of this study was to identify sources of anatomical misrepresentation due to the location of camera mounting, tumour motion velocity and image processing artefacts in order to optimise the 4DCT scan protocol and improve geometrical-temporal accuracy.

A phantom with an imaging insert was driven with a sinusoidal superior-inferior motion of varying amplitude and period for 4DCT scanning. The length of a high density cube within the insert was measured using treatment planning software to determine the accuracy of its spatial representation. Scan parameters were varied including the tube rotation period and the cine time between reconstructed images. A CT image quality phantom was used to measure various image quality signatures under the scan parameters tested.

No significant difference in spatial accuracy was found for 4DCT scans carried out using the wall mounted or couch mounted camera for sinusoidal target motion. Greater spatial accuracy was found for 4DCT scans carried out using a tube rotation speed of 0.5s rather than 1.0s. The reduction in image quality when using a faster rotation speed was not enough to require an increase in patient dose.

4DCT accuracy may be increased by optimising scan parameters, including choosing faster tube rotation speeds. Peak misidentification in the recorded breathing trace leads to spatial artefacts and this risk can be reduced by using a couch mounted infrared camera.

This study explicitly shows that 4DCT scan accuracy is improved by scanning with a faster CT tube rotation speed.

Image, Video and 3D Data Registration: Medical, Satellite and Video Processing Applications with Quality Metrics

Data registration refers to a series of techniques for matching or bringing similar objects or datasets together into alignment. These techniques enjoy widespread use in a diverse variety of applications, such as video coding, tracking, object and face detection and recognition, surveillance and satellite imaging, medical image analysis and structure from motion. Registration methods are as numerous as their manifold uses, from pixel level and block or feature based methods to Fourier domain methods.

This book is focused on providing algorithms and image and video techniques for registration and quality performance metrics. The authors provide various assessment metrics for measuring registration quality alongside analyses of registration techniques, introducing and explaining both familiar and state-of-the-art registration methodologies used in a variety of targeted applications.

Key features:
- Provides a state-of-the-art review of image and video registration techniques, allowing readers to develop an understanding of how well the techniques perform by using specific quality assessment criteria
- Addresses a range of applications from familiar image and video processing domains to satellite and medical imaging among others, enabling readers to discover novel methodologies with utility in their own research
- Discusses quality evaluation metrics for each application domain with an interdisciplinary approach from different research perspectives

Energy-Aware Rate and Description Allocation Optimized Video Streaming for Mobile D2D Communications

The proliferation problem of video streaming applications and mobile devices has prompted wireless network operators to put more efforts into improving quality of experience (QoE) while saving resources that are needed for high transmission rate and large size of video streaming. To deal with this problem, we propose an energy-aware rate and description allocation optimization method for video streaming in cellular network assisted device-to-device (D2D) communications. In particular, we allocate the optimal bit rate to each layer of video segments and packetize the segments into multiple descriptions with embedded forward error correction (FEC) for realtime streaming without retransmission. Simultaneously, the optimal number of descriptions is allocated to each D2D helper for transmission. The two allocation processes are done according to the access rate of segments, channel state information (CSI) of D2D requester, and remaining energy of helpers, to gain the highest optimization performance. Simulation results demonstrate that our proposed method (named OPT) significantly enhances the performance of video streaming in terms of high QoE and energy saving.

Evaluation of Video Presentation to Deliver Surgical Anatomy Teaching

Title Evaluation of Video Presentation to Deliver Surgical Anatomy Teaching

Authors Walsh I.K., Boohan M., Dorman A.

Objectives To evaluate the efficacy of newly introduced video presentation to deliver Surgical Anatomy teaching to undergraduate medical students.

Design and Setting Qualitative and quantitative study using questionnaires and focus groups, employing students undertaking the perioperative medicine module of the phase 4 undergraduate medical curriculum at Queen’s University Belfast.

Outcome Measures To determine:
(1) if video presentation is effective in delivering surgical anatomy teaching,
(2) student’s learning preferences regarding this teaching method.
Results The questionnaire response rate was 89% (216 of 244 students; female: male ratio 1.25) and 42 students participated in 6 focus groups. Mean questionnaire responses indicated a favourable opinion on quality assurance items, with a mixed response to video presentation as a learning method. 71% of students preferred to receive a lecture in person, rather than via video presentation. There were no statistically significant differences between genders regarding learning preferences in general and regarding video versus live presentation in particular. Exploratory factor analysis demonstrated that favourable responses to video presentation were strongly associated with perceived audiovisual quality and learning preferences (Cronbach’s alpha coefficient 0.77), with 72% of students considering video presentation worthwhile. Positive perception of overall quality was strongly associated with learning preferences as well as more generic quality assurance issues (80% students; alpha coefficient 0.83).
The results were supported by triangulation of the above quantitative data with qualitative data generated by the focus groups. Students further articulated the view that video presentation may be more appropriate and effective in a mixed method setting.

Reference Basu Roy R, McMahon GT. Video-based cases disrupt deep critical thinking in problem-based learning. Med Educ 2012 Apr;46(4):426-435.

Video clip: Understanding ‘Wellbeing’ in the Lives of Adolescents with Disabilities

This short (2 minute) digital media clip was designed in consultation with an advisory group of young people with disabilities, as a means of providing information about a research project to potential participants. This format was used to overcome barriers whereby written information may not have been appropriate to the young person’s needs. It also allowed the researchers to introduce themselves to the young people and become familiar to them before face-to-face meeting.

Evidence reasoning for event inference in smart transport video surveillance

In this paper we present a new event recognition framework, based on the Dempster-Shafer theory of evidence, which combines the evidence from multiple atomic events detected by low-level computer vision analytics. The proposed framework employs evidential network modelling of composite events. This approach can effectively handle the uncertainty of the detected events, whilst inferring high-level events that have semantic meaning with high degrees of belief. Our scheme has been comprehensively evaluated against various scenarios that simulate passenger behaviour on public transport platforms such as buses and trains. The average accuracy rate of our method is 81% in comparison to 76% by a standard rule-based method.