Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critica... more Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critically assessing police and government claims that CCTV is effective in reducing crime. This paper presents a fi eld study that investigates the relationship between CCTV system design and the performance of operator tasks. We carried out structured observations and interviews with 13 managers and 38 operators at 13 CCTV control rooms. A number of failures were identifi ed, including the poor confi guration of technology, poor quality video recordings, and a lack of system integration. Stakeholder communication was poor, and there were too many cameras and too few operators. These failures have been previously identifi ed by researchers; however, no design improvements have been made to control rooms in the last decade. We identify a number of measures to improve operator performance, and contribute a set of recommendations for security managers and practitioners.
Despite the increased usage of surveillance systems and the technological advances, there is curr... more Despite the increased usage of surveillance systems and the technological advances, there is currently no conceptual basis and little evidence to assess how well CCTV actually works for the purposes for which it is deployed. It is important to identify whether CCTV systems and applications meet stakeholder goals, and support human operators effectively, in attaining the goals for which the system is set up. This exploratory paper highlights the early findings found in CCTV control rooms. A series of ethnographic observations along with semi-structured interviews were carried out at six CCTV public surveillance control rooms – six managers, six supervisors and 25 operators were interviewed. Findings reveal that current control room systems are not designed to support operator and system communication and collaboration when performing their tasks. Poor linked technology and a lack of task coordination was evident between operators and external agencies such as police operators and loc...
Research into control design and operations confirms what many of us suspected: technology in CCT... more Research into control design and operations confirms what many of us suspected: technology in CCTV control rooms often fails to meet the needs of those who have to use it. Hina Keval, a PhD student at University College London, talked to us about her research findings. RANGING FROM EARLIER 1990s papers by the likes of academics such as professor Jason Ditton, Nick Tilley and Clive Norris, through to more recent and wide ranging probes by experts including Perpetuity's professor Martin Gill, it would seem that after ten years the sector has been thoroughly worked over by investigations into its many different aspects. Yet, scanned by the eye of an industry outsider, it recently became clear that a more detailed look at the 'human factors' involved in control room operations merited a more detailed overhaul. That was the view of Hina Keval, a graduate student working towards her PhD at University College London. Hina originally did a four-year undergraduate degree at Lough...
The journey one must make to earn a PhD can be very lonely. I am fortunate to have had the suppor... more The journey one must make to earn a PhD can be very lonely. I am fortunate to have had the support of many people from academia and industry along the way. I am sincerely indebted and thankful to all of them. This work could not have come together without their help. I would like to acknowledge that this PhD research was funded by the European Physical Science Research Council (EPSRC) 2004-2007, grant no. EP1P50064811. I am most grateful to my dedicated supervisors Prof. M. Angela Sasse and Dr Simon Prince. Angela has given me great confidence, encouragement, guidance, and a tremendous amount of support throughout my research studies. I would like to thank my second supervisor, Simon, who kindly gave me advice and constructive comments on the empirical parts of my research. A very big thank you goes to Hendrik Knoche, my official PhD mentor, colleague, and friend. Hendrik provided me with guidance on my video quality experiments and taught me a great deal about video, imaging and data analysis. Thank you to Dimitris Miras who provided feedback on my early experimental ideas and offered his expertise on video quality. I would also like to thank Dr Paul Cairns (formerly of UCLIC and now at York University) who was so willing to offer his time to review my research papers and offer guidance on data analysis for my empirical experiments-even on short notice. I would like to thank Hendrik Knoche and Sven Laqua who helped me program my experiments. I am also very grateful to all of my colleagues in the Department of Computer Science who provided their opinions on my research ideas and gave their time to review papers and drafts:
Ergonomics and Safety Research Institute, Loughborough University, Jul 1, 2005
Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work ... more Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work on gathering data on consumer needs. Following a user-centred approach, a large number of novel usage scenarios were developed and discussed within the team. A consumer ...
A subjective quality test was undertaken to quantify the amount by which the perceived quality of... more A subjective quality test was undertaken to quantify the amount by which the perceived quality of full-face digital video (such as a newsreader) varies with the spatial location of degradation. It was found that perceived error was greatest for degradation occurring around the eyes and mouth. Traditional digital video assessment techniques, such as peak signal-to-noise ratio, rate all errors equally, irrespective of spatial location and thus do not give a meaningful measure of perceived quality.
Introduction: To design effective digital electronic broadcast and communication systems, it is n... more Introduction: To design effective digital electronic broadcast and communication systems, it is necessary to understand how the user interacts with the technology involved. Perceptible errors may occur in the visual data stream in practical systems. However, while the errors can be identified and measured objectively in engineering terms, characterisation of subjective quality opinion presents a challenge. It is important that the subjective opinion of individual users is understood when assessing degraded video quality, so that a reliable measure of perceived quality of service can be achieved. Traditional objective methods of assessing picture quality include the peak signal‐to‐noise ratio (PSNR). This Letter describes an experiment where areas of a talking‐head digital video image (full‐face, such as a newsreader) were degraded at different spatial locations and participants were asked for their subjective opinion of the error. The aim of the study was, first, to quantify the deg...
Proceeding of the 16th ACM international conference on Multimedia - MM '08, 2008
The new generation of digital CCTV systems can be tailored to serve a wide range of security requ... more The new generation of digital CCTV systems can be tailored to serve a wide range of security requirements. However, many digital CCTV systems produce video which is insufficient in quality to support specific security tasks, such as crime detection. We report a study investigating the impact of lowering frame rates on an observer's ability to distinguish between crime and no crime events from post-event recorded video. 80 participants viewed 32 video scenes at 1, 5, 8, and 12 frames per second (fps). The task required observers to determine if one of three possible events had occurred. Results showed that when the frame rate was lowered from 8fps, the number of correct detections and task confidence decreased significantly. Our results provide CCTV practitioners with a minimum frame rate level (8 fps) for event detection, a task performed by CCTV users of varying skill and experience.
Mobile Multimedia/Image Processing, Security, and Applications 2008, 2008
CCTV is used for an increasing number of purposes, and the new generation of digital systems can ... more CCTV is used for an increasing number of purposes, and the new generation of digital systems can be tailored to serve a wide range of security requirements. However, configuration decisions are often made without considering specific task requirements, e.g. the video quality needed for reliable person identification. Our study investigated the relationship between video quality and the ability of untrained viewers to identify faces from digital CCTV images. The task required 80 participants to identify 64 faces belonging to 4 different ethnicities. Participants compared face images taken from a high quality photographs and low quality CCTV stills, which were recorded at 4 different video quality bit rates (32, 52, 72 and 92 Kbps). We found that the number of correct identifications decreased by 12 (~18%) as MPEG-4 quality decreased from 92 to 32 Kbps, and by 4 (~6%) as Wavelet video quality decreased from 92 to 32 Kbps. To achieve reliable and effective face identification, we recommend that MPEG-4 CCTV systems should be used over Wavelet, and video quality should not be lowered below 52 Kbps during video compression. We discuss the practical implications of these results for security, and contribute a contextual methodology for assessing CCTV video quality.
Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critica... more Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critically assessing police and government claims that CCTV is effective in reducing crime. This paper presents a fi eld study that investigates the relationship between CCTV system design and the performance of operator tasks. We carried out structured observations and interviews with 13 managers and 38 operators at 13 CCTV control rooms. A number of failures were identifi ed, including the poor confi guration of technology, poor quality video recordings, and a lack of system integration. Stakeholder communication was poor, and there were too many cameras and too few operators. These failures have been previously identifi ed by researchers; however, no design improvements have been made to control rooms in the last decade. We identify a number of measures to improve operator performance, and contribute a set of recommendations for security managers and practitioners.
Despite increased usage of CCTV, and technological advances of surveillance systems, there is sti... more Despite increased usage of CCTV, and technological advances of surveillance systems, there is still relatively little understanding of how well it actually works for the many purposes for which it is deployed. Most purposes require that humans detect and respond ...
Ergonomics and Safety Research Institute, Loughborough University, Jul 1, 2005
Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work ... more Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work on gathering data on consumer needs. Following a user-centred approach, a large number of novel usage scenarios were developed and discussed within the team. A consumer ...
Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critica... more Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critically assessing police and government claims that CCTV is effective in reducing crime. This paper presents a fi eld study that investigates the relationship between CCTV system design and the performance of operator tasks. We carried out structured observations and interviews with 13 managers and 38 operators at 13 CCTV control rooms. A number of failures were identifi ed, including the poor confi guration of technology, poor quality video recordings, and a lack of system integration. Stakeholder communication was poor, and there were too many cameras and too few operators. These failures have been previously identifi ed by researchers; however, no design improvements have been made to control rooms in the last decade. We identify a number of measures to improve operator performance, and contribute a set of recommendations for security managers and practitioners.
Despite the increased usage of surveillance systems and the technological advances, there is curr... more Despite the increased usage of surveillance systems and the technological advances, there is currently no conceptual basis and little evidence to assess how well CCTV actually works for the purposes for which it is deployed. It is important to identify whether CCTV systems and applications meet stakeholder goals, and support human operators effectively, in attaining the goals for which the system is set up. This exploratory paper highlights the early findings found in CCTV control rooms. A series of ethnographic observations along with semi-structured interviews were carried out at six CCTV public surveillance control rooms – six managers, six supervisors and 25 operators were interviewed. Findings reveal that current control room systems are not designed to support operator and system communication and collaboration when performing their tasks. Poor linked technology and a lack of task coordination was evident between operators and external agencies such as police operators and loc...
Research into control design and operations confirms what many of us suspected: technology in CCT... more Research into control design and operations confirms what many of us suspected: technology in CCTV control rooms often fails to meet the needs of those who have to use it. Hina Keval, a PhD student at University College London, talked to us about her research findings. RANGING FROM EARLIER 1990s papers by the likes of academics such as professor Jason Ditton, Nick Tilley and Clive Norris, through to more recent and wide ranging probes by experts including Perpetuity's professor Martin Gill, it would seem that after ten years the sector has been thoroughly worked over by investigations into its many different aspects. Yet, scanned by the eye of an industry outsider, it recently became clear that a more detailed look at the 'human factors' involved in control room operations merited a more detailed overhaul. That was the view of Hina Keval, a graduate student working towards her PhD at University College London. Hina originally did a four-year undergraduate degree at Lough...
The journey one must make to earn a PhD can be very lonely. I am fortunate to have had the suppor... more The journey one must make to earn a PhD can be very lonely. I am fortunate to have had the support of many people from academia and industry along the way. I am sincerely indebted and thankful to all of them. This work could not have come together without their help. I would like to acknowledge that this PhD research was funded by the European Physical Science Research Council (EPSRC) 2004-2007, grant no. EP1P50064811. I am most grateful to my dedicated supervisors Prof. M. Angela Sasse and Dr Simon Prince. Angela has given me great confidence, encouragement, guidance, and a tremendous amount of support throughout my research studies. I would like to thank my second supervisor, Simon, who kindly gave me advice and constructive comments on the empirical parts of my research. A very big thank you goes to Hendrik Knoche, my official PhD mentor, colleague, and friend. Hendrik provided me with guidance on my video quality experiments and taught me a great deal about video, imaging and data analysis. Thank you to Dimitris Miras who provided feedback on my early experimental ideas and offered his expertise on video quality. I would also like to thank Dr Paul Cairns (formerly of UCLIC and now at York University) who was so willing to offer his time to review my research papers and offer guidance on data analysis for my empirical experiments-even on short notice. I would like to thank Hendrik Knoche and Sven Laqua who helped me program my experiments. I am also very grateful to all of my colleagues in the Department of Computer Science who provided their opinions on my research ideas and gave their time to review papers and drafts:
Ergonomics and Safety Research Institute, Loughborough University, Jul 1, 2005
Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work ... more Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work on gathering data on consumer needs. Following a user-centred approach, a large number of novel usage scenarios were developed and discussed within the team. A consumer ...
A subjective quality test was undertaken to quantify the amount by which the perceived quality of... more A subjective quality test was undertaken to quantify the amount by which the perceived quality of full-face digital video (such as a newsreader) varies with the spatial location of degradation. It was found that perceived error was greatest for degradation occurring around the eyes and mouth. Traditional digital video assessment techniques, such as peak signal-to-noise ratio, rate all errors equally, irrespective of spatial location and thus do not give a meaningful measure of perceived quality.
Introduction: To design effective digital electronic broadcast and communication systems, it is n... more Introduction: To design effective digital electronic broadcast and communication systems, it is necessary to understand how the user interacts with the technology involved. Perceptible errors may occur in the visual data stream in practical systems. However, while the errors can be identified and measured objectively in engineering terms, characterisation of subjective quality opinion presents a challenge. It is important that the subjective opinion of individual users is understood when assessing degraded video quality, so that a reliable measure of perceived quality of service can be achieved. Traditional objective methods of assessing picture quality include the peak signal‐to‐noise ratio (PSNR). This Letter describes an experiment where areas of a talking‐head digital video image (full‐face, such as a newsreader) were degraded at different spatial locations and participants were asked for their subjective opinion of the error. The aim of the study was, first, to quantify the deg...
Proceeding of the 16th ACM international conference on Multimedia - MM '08, 2008
The new generation of digital CCTV systems can be tailored to serve a wide range of security requ... more The new generation of digital CCTV systems can be tailored to serve a wide range of security requirements. However, many digital CCTV systems produce video which is insufficient in quality to support specific security tasks, such as crime detection. We report a study investigating the impact of lowering frame rates on an observer's ability to distinguish between crime and no crime events from post-event recorded video. 80 participants viewed 32 video scenes at 1, 5, 8, and 12 frames per second (fps). The task required observers to determine if one of three possible events had occurred. Results showed that when the frame rate was lowered from 8fps, the number of correct detections and task confidence decreased significantly. Our results provide CCTV practitioners with a minimum frame rate level (8 fps) for event detection, a task performed by CCTV users of varying skill and experience.
Mobile Multimedia/Image Processing, Security, and Applications 2008, 2008
CCTV is used for an increasing number of purposes, and the new generation of digital systems can ... more CCTV is used for an increasing number of purposes, and the new generation of digital systems can be tailored to serve a wide range of security requirements. However, configuration decisions are often made without considering specific task requirements, e.g. the video quality needed for reliable person identification. Our study investigated the relationship between video quality and the ability of untrained viewers to identify faces from digital CCTV images. The task required 80 participants to identify 64 faces belonging to 4 different ethnicities. Participants compared face images taken from a high quality photographs and low quality CCTV stills, which were recorded at 4 different video quality bit rates (32, 52, 72 and 92 Kbps). We found that the number of correct identifications decreased by 12 (~18%) as MPEG-4 quality decreased from 92 to 32 Kbps, and by 4 (~6%) as Wavelet video quality decreased from 92 to 32 Kbps. To achieve reliable and effective face identification, we recommend that MPEG-4 CCTV systems should be used over Wavelet, and video quality should not be lowered below 52 Kbps during video compression. We discuss the practical implications of these results for security, and contribute a contextual methodology for assessing CCTV video quality.
Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critica... more Previous research on the effectiveness of Closed Circuit Television (CCTV) has focused on critically assessing police and government claims that CCTV is effective in reducing crime. This paper presents a fi eld study that investigates the relationship between CCTV system design and the performance of operator tasks. We carried out structured observations and interviews with 13 managers and 38 operators at 13 CCTV control rooms. A number of failures were identifi ed, including the poor confi guration of technology, poor quality video recordings, and a lack of system integration. Stakeholder communication was poor, and there were too many cameras and too few operators. These failures have been previously identifi ed by researchers; however, no design improvements have been made to control rooms in the last decade. We identify a number of measures to improve operator performance, and contribute a set of recommendations for security managers and practitioners.
Despite increased usage of CCTV, and technological advances of surveillance systems, there is sti... more Despite increased usage of CCTV, and technological advances of surveillance systems, there is still relatively little understanding of how well it actually works for the many purposes for which it is deployed. Most purposes require that humans detect and respond ...
Ergonomics and Safety Research Institute, Loughborough University, Jul 1, 2005
Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work ... more Consumer and Supplier research In the Services Aggregation trial, ESRI and Foodware led the work on gathering data on consumer needs. Following a user-centred approach, a large number of novel usage scenarios were developed and discussed within the team. A consumer ...
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Papers by Hina Keval