Visualization techniques to support CCTV operators of smart city services

Abstract

In this paper visualization techniques for modern closed circuit television (CCTV) smart city services are discussed with application to prevention of threats. Unconventional approaches to the intelligent visual data processing are proposed in order to support video surveillance operators, thus to make their work less exhaustive and more effective. Although registration of a huge amount of video data requires development of intelligent and automatic signal processing information extraction techniques, improvement of visualization methods for operators is also a very important task, because of the crucial role the human factor plays and should always play in the decision making, e.g. in the operator reactions to various crisis situations, which can never be fully eliminated by artificial intelligence. Four software based mechanisms connected with a standard or with a slightly extended hardware are proposed as options for the CCTV operators. They utilize rather known ideas but are implemented with new extensions to original algorithms, as well as with additional, innovative modifications and solutions (not presented in the literature). With them they become reliable and efficient tools for the CCTV systems. First, generation of cylindrical panoramas is suggested in order to make long-time video content analysis of a defined area easier and faster. Using panoramas it is possible to reduce the time that is required to watch the video by a factor of hundreds or even thousands and perform an efficient compression of the video stream for the long-time storage. Second, the controlled stereovision option is discussed for quicker and more precise extraction of relevant information from the observed scene. Third, the thermo-vision is analyzed for faultless detection of pedestrians at night. Finally, a novel high dynamic range (HDR) technique is proposed, dedicated to the CCTV systems, in contrast to other typical entertainment oriented HDR approaches, for clear visualization of important and meaningful image details, otherwise invisible. We validated usefulness of the proposed techniques with many experiments presented in this paper.

Inflated 3D ConvNet context analysis for violence detection

“…The cost function can be expressed as shown in Eq. ( 1): c i, j = λd (1) (i, j) + (1 − λ)d (2) (i, j)…”

“…where d (1) denotes the Mahalanobis distance of the detected BB from the position predicted according to the previously known position of the corresponding object, while the visual distance d (2) considers the appearance of the presently detected object compared with the history of appearance of the tracked object to which it is expected to correspond. The present proposal exploits a recent version of the algorithm.…”

“…The present proposal exploits a recent version of the algorithm. 1 Even though Deep SORT achieves overall good performance in terms of tracking precision and accuracy, the kind of situations considered in violence detection can raise peculiar problems. As a matter of fact, fight scenes present aggressive human pose changes and occlusions that lead to a relatively high number of identity switches (see the left column of Fig.…”

“…The advantage is that these can be automatically raised by an automatic system therefore relieving the operator from the burden of a continuous attention. This is especially useful with multiple surveillance cameras, e.g., to decide which surveillance video stream to display on the main monitor for anomaly confirmation [1,2].…”

Tuning of Classifiers to Speed-Up Detection of Pedestrians in Infrared Images

“…Human bodies with temperatures of around 300 K have the highest energy emission in this band. As a result, the FIR images have a high contrast between living creatures and the environment [28]. Passive systems also provide a large detection range for high-quality cameras (up to 300 m).…”