General/Background
The word “Surveillance” is derived from the French word “sur” which means “from above” and “veiller” which means “to watch.” It includes observing from technological/electronic means (Closed Circuit Television cameras etc) or lesser technological means (intelligence agents, detectives etc) both. It has long been used by governments, organizations for intelligence gathering, crime prevention, investigations, safeguarding people and their properties etc. Despite its obvious advantages, it also ignited controversies like concerns about privacy, stigmatization and its susceptibility to abuse etc. With the advancement in technology, the internet protocol (IP) based structure of the advanced surveillance systems has proven to be more flexible, adaptable and versatile with enhanced digital security. This article is aimed at providing an insight to the security managers about video surveillance and its important role in enhancing the security of any facility.
Brief History of Video Surveillance
Starting with black and white images to films to analog cameras to IP cameras with storages initially in Digital Video Recorder (DVRs) or Network Video Recorders (NVRs) to cloud, video surveillance has come a long way in the past 80 years. A brief preview is shown in the figure below:-
What is Video Surveillance/CCTV (Closed Circuit Television)?
Video surveillance means observing a scene(s) and searching for unusual behaviors, activities or something that might indicate a likely unusual behavior/activity. A simple Video Surveillance System (VSS) or CCTV consists of a number of cameras, monitors as well as recorders. Cameras installed could be analog or digital; can be placed as per the requirement (both inside and outside the facility) and are able to function 24/7, during specific timings or even in response to some movement. Ethically, if a facility uses CCTV, people need to be informed that they are being recorded. Video can be seen either live or remotely using IP cameras, or can even be recorded and stored using a DVR or NVR to be reviewed later. CCTV is termed as closed-circuit because the signals are not transmitted openly as it is with broadcast television; instead, the cameras installed to transmit the video/footage back to predefined monitors with only a limited number of people who can access it. These systems are used for security (both private and public property security) and monitoring and surveillance (crime prevention or investigation) purposes.
Cameras that can make up a Video Surveillance System
Cameras are the backbone of any video surveillance system. Their precise positioning coupled with the type under various conditions is crucial in video surveillance. A large variety of cameras (both analog and digital) are being used for video surveillance for different premises or situations thereby making their selection even more vital. Internet Protocol Cameras fall in the category of digital cameras.
Positioning of Cameras: In order to record relevant videos, positioning of cameras need to be done intelligently. The most appropriate areas for their placement could be entrances, parking areas, T-Junctions, exits, areas with higher density of people or vehicles, schools, restaurants, VIP movement areas/roads etc.
Types of Cameras to be placed: There is a large variety of cameras available in the market and the suitability entirely depends on the situation as well as the budget. While a fixed camera can record video in a specific direction, a Pan-Tilt-Zoom (PTZ) camera can use pan, tilt, and zoom functionality to provide both wide-area coverage and great detail. Static locations mostly use fixed cameras being less costly than PTZ cameras whereas, for the night or lesser lit areas, thermal/infrared cameras are generally preferred, however, the resolution of these cameras may differ.
Analog Cameras: Lower resolution cameras with hook-ups to the DVR and wired connections for power are generally termed as analog cameras. In order to have better quality video/footage, these cameras need to be placed near the DVR. Their range (visual) is generally lesser than IP/digital cameras warranting larger number of such cameras needed to cater for same amount of space that one IP camera can cover. Besides, the footage might distort further if an attempt is made to zoom in and enlarge the image. These analog cameras are relatively cheaper and have more design options with a reasonable price tag and far lesser use of network bandwidth, unlike IP/Digital cameras. Few important types are briefly summarized below:
Internet Protocol (IP) Cameras: Internet protocol (IP) cameras (also known as network cameras) refer to a digital video camera capable of sending and receiving data through a computer network instead of sending the feed to a DVR. IP cameras are digital cameras that provide much higher resolution images than analog cameras do. They digitize the recordings within the camera as opposed to the analog recordings which are digitized on the computer. These cameras have wider range of vision and numerous added features like motion-triggered auto-recording, smart-technology and object recognition options. There are many advantages of IP cameras includes picture quality, video analytics and flexibility/scalability. The minuses associated with digital IP cameras include their significantly high cost; require more bandwidth from your network to transmit the images and more storage. They do have the provision of Wi-Fi enabled cameras allowing their feed to be remotely accessible but at the same time hackable.
Picture Quality: It is a known fact that the best analog surveillance camera cannot even match the worst IP camera in terms of quality of image it captures. Besides, IP cameras capture a much wider field of view as compared to the analog cameras resulting into one IP camera capable of doing the job of many analog cameras.
Flexibility and Scalability: In an analog DVR set-up, every camera has to be connected directly to the DVR whereas the IP cameras can use switches which allow cameras nearby to be connected to a single switch, which is then connected to the NVR (Network Video Recorder) and reduces the cabling overflow and eventually less labor intensive. In addition, it also allows you to connect additional cameras because you are not constrained by the number of ports on your DVR.
Video Analytics: It means setting your network to raise flags in case of any “event” that happens in the camera’s field of view. The events could be tempering with the camera, motion detection, anything unusual etc. Hence, instead of wasting hours and hours in determining what happened, where and when, the network can draw your attention directly to that precise event.
PTZ Cameras: PTZ cameras are constructed with the help of mechanical parts which allow them to rotate right-left, tilt up-down, and zoom in and out. Zooming in and out facility provides the operators the leverage to magnify desired areas and cover gaps. These cameras are generally used to monitor wide areas and are controlled by an individual with the help of a remote camera controller. Modern PTZ cameras like Sony SRG-300H have the provision to be programmed to automatically follow motion-triggered activity (auto tracking) in any area. Generally, these cameras are deployed in tandem with fixed cameras in a large surveillance system, wherein PTZ cameras track movement while the fixed cameras capture detailed shots.
Intelligent Video System Features
Traditional video surveillance systems (using analog cameras) generally result in thousands of hours of blurry (particularly once zoomed in) and often unusable video which does not serve the real purpose of effective surveillance for investigation and monitoring. On the contrary, intelligent videos can proffer following improvements:
• Suspicious activities detection through audio and visual means automatically resulting into triggering of alarms and alerting the residents/facility owner about potential threats.
• Capable of keeping a strong check of all incoming and outgoing people including their count.
• Highly improved searching ability in minimum possible time and raising flags/alerting only on events that occurred in a specific time frame saving valuable time and getting to the real incident quickly.
• Improved night vision capability with extremely high picture quality obtained through advanced motion sensors. This means that the system is actually idle if there is no activity/movement at the location.
• Tracking a moving object.
• Initiation of video recording, alarms, alerts, or other actions.
• Raising flags; alerting security operators and seeking for help.
• Camera tampering detection.
• License plate recognition of all incoming and outgoing vehicles.
Video Management System (VMS)
In any VMS, footages are taken by the cameras and stored, managed and transmitted to authorized security operators/managers. The VMS generally used in any video surveillance systems include:-
DVRs: In a DVR, video footages are recorded directly from a surveillance camera on a hard disk. These DVRs are faster and more flexible as compared to previously used analog VHS tape systems. They also allow much faster video transmission over the computer network. The main drawback of DVRs is that they accept analog camera feeds only as input, however, support remote viewing over the internet.
Hybrid Digital Video Recorders (HDVRs) support IP cameras too. These recorders are able to perform all functions of a digital video recorder mentioned above and in addition, they also support IP and megapixel cameras.
Third category, the Network Video Recorders (NVR) supports IP cameras only can use encoder to support analog cameras as well. NVR has the capability to record videos from a large number of digital cameras.
IP video surveillance cameras have already been discussed above and the client has to use a PC/server for it to be used, not only it becomes cost effective, it becomes the mostly sought after cameras for video systems that contain extensive camera tallies.
Type of Storages
Storage of surveillance video is required so that it can be reviewed later, however, the duration for which the video should be stored varies and depends upon the cost as well as the security circumstances. For example, in public areas, video footages may be kept for a relatively shorter duration as compared to banks where they are generally kept for longer duration as fraudulent incidents in banks may surface after days/weeks or even months. The data is stored in the different kinds of storages which remains stored there unless deleted. Storage devices may include magnetic disks, hard drives (can provide a storage of 2 TB to 4 TB), solid-state drives (SSDs-Non-volatile storage devices capable of holding large amounts of data), purpose built surveillance hard drives particularly optimized for video security use with advanced energy conserving features, optical storage devices like CDs, DVDs, Blu Ray drives and USBs, etc. With the advent of this new breed of dedicated, optimized, power efficient surveillance hard drives, video surveillance systems can now deliver optimal performance with efficiency.
The term Cloud Surveillance is actually the remote storage of footages over the internet which does not require any physical equipment or wires but an internet connection only. With the technology improving leaps and bounds, this cloud storage has allowed users to store video footages remotely without bothering about storage capacity with extremely simple setup process and minimal equipment.
Monitoring of Video Surveillance System
Video footages have to be monitored by the operators and generally used for any investigations. The frequency of this viewership differs depending upon the location where the system is installed. Viewership can be local where the video is viewed directly from the DVR; can be remote where the live video can be seen remotely through some app or even a web browser; can be seen on mobiles providing an instant check of the location being viewed and for large facilities, could have a video wall, a big screen where many people can watch video captured from multiple cameras.
Latest Technological Trends in Video Surveillance
AI Video Analytics Leveraging Deep Learning.
AI, using its components, machine learning, and deep learning, is already driving innovation by offering improved data and it is expected that the Deep Learning technology would make video surveillance even more accurate while lowering costs. Deep Learning will also speed up investigations significantly by allowing quick search and filter that used to take hours earlier, based on specific criteria.
Low Contact Solutions.
With the Covid-19 pandemic still haunting the world, touch-less solutions with AI enabled cameras will automate many processes remotely For example, in video surveillance, the use of license plate recognition will be popular to minimize contact risk.
Cyber Security – Major Video Surveillance Concern.
Around 4000 cyber security complaints were received in the US alone last year particularly in the wake of pandemic owing to larger number of IoT devices being connected to the internet making CCTV hacking serious concerns for organizations and all.
Increased number of Mobile Applications.
Significant improvements in web and mobile applications being able to provide similar information beyond traditional video sharing are already in use. Instead of desktops, users are able to perform similar functions using their mobiles/laptops.
Demands for Higher Resolution.
In order to accrue maximum benefits of video for operational/surveillance activities, users are now asking for higher video quality. This can be achieved, however, would require better performing hardware with faster processing storage capabilities. The next challenge would then be to integrate this hardware with the right VMS that can best optimize large volume of video footages being continuously stored.
Growth of 5G.
With 5G infrastructure growing, the possibility of having Video Surveillance as a Service (VSaaS) also increases. This means that the users will be able to store, manage, record, play, and monitor video footage in the cloud and not on NVRs or drives.
Migration to Hybrid Cloud Mindset.
While a public cloud refers to an IT model where computing services/infrastructure is managed by a third-party service provider and shared with many organizations through internet, private cloud is the one where the infrastructure is dedicated to a single user organization. Hybrid cloud actually refers to a combination of both and allows data and apps to move between the two environments such as Amazon Web Services (AWS) or Microsoft Azure.
Conclusion
Over the last couple of decades, exponential technological growth has been noticed in security industry across the globe. With the increased demand, significant research has been conducted in video surveillance as well. An Intelligent Video Surveillance system monitored the occurrences of events or changes of routine in terms of human beings, vehicles etc from a distance with the help of electronic equipment (mostly digital cameras). In order to prevent, detect and intervene timely, advanced video surveillance systems have been developed with intelligent video processing capabilities with a view to assist security managers/staff by providing reliable information and raising real-time flags/alerts and to support efficient video analysis for further investigations.
