Furthermore, the design of a fixed dome network camera can better fit in with the decor. A fixed dome network camera can be furnished with a weather- or vandal-proof housing for outdoor applications.
With a high zoom capability, image stabilization and degree endless pan, a speed dome camera is mainly used for professional applications, such as airports, banks or city security. A video server mainly includes a compression chip and an Ethernet chip, with two main types available: one port or four ports. Aimed to store digital video streams from network cameras, an NVR is usually incorporated with a large-volume hard disk to allow for a long period of recording.
An NVR differs from a traditional DVR in its network connectivity, which allows digital data to be transmitted to other networked devices over the Internet. Another difference is that an NVR can be directly connected to a network camera while a DVR is usually be connected to an analog camera. Typically, central management software is windows- based, and thus can be installed in almost any PC.
Central management software employs client-server architecture where server software,client viewing software and playback software is installed in separate PCs. Customers can perform live viewing, event-triggered recording or playback on the client PC while managing cameras and performing constant recording with the server PC. Each server PC can be scaled up to include several subordinate server PCs, and thus expand the number of managed cameras.
The development of surveillance systems is segmented into three periods, known as the first, second and third generation. Camera images are transmitted via coaxial cables and stored in VCR cassettes. Due to limited storage capacity, the cassettes must be replaced frequently for a long period of recording.
The early s saw the emergence of the second-generation surveillance system, which is composed of CCTV cameras, DVRs and digital monitors. Analog camera images are digitized and stored in DVRs.
NVRs provide remote data access and management capability. The third-generation surveillance system, also known as IP surveillance, appeared in early Users can remotely control, monitor and record live video Figure 1.
In addition, IP surveillance has no signal degradation problems during transmission, and thus can ensure steady image quality. However, for camera itself, a lens is the most fundamental component that firstly decides if the output of the quality is good or not. In contrast, the longer the focal length, the smaller viewing angle and field of object it has.
The most common vari-focal lens is 3. Generally, AF Auto Focus algorithm is used to focus automatically. Iris is one of the most important elements for light sensitivity, along with aperture, shutter time, sensor, and gain. Iris Figure 2.
Iris size is inversely proportional to F-number. Every time the F-number increases towards a larger number, the exposure ratio will reduce by half Figure 2. It is used when light sources are steady. Auto-iris Auto-iris can automatically adjust the amount of light entering with a mechanism to have a camera stay in an optimal light level. As a result, it is mainly required for outdoor applications or the places where lights change frequently.
There are two types of auto-iris: Video-drive iris and DC-drive iris. Because the amplifier circuit is built in the lens, a Video-drive iris lens is more expensive. Due to the drive circuit is integrated in the camera instead of in the lens, DC-drive iris lens features lower costs. The flange focal distance for a CS-mount lens is A CS-mount lens has higher cost efficiency and smaller size because fewer glass components are used.
The innovative method improves lens compatibility and installation. Each pixel on a CMOS sensor is accompanied by an amplifier based on p-n junction structure. The p-n junction structure receives photons from the sensor and transmits them to an image signal processor. A CCD is an analog shift register that enables the transportation of analog signals electric charges through successive stages capacitors , controlled by a clock signal.
The analog signals in each row of the capacitors are transmitted and converted to digital via an analog-to-digital IC. Table 2. For example, a resolution of x means the horizontal row consists of pixels and the vertical column includes lines. The resolution of the entire image is thus around 1.
The higher the resolution, the more information can be rendered, and thus the better image quality. NTSC signals can be displayed on a black-and-white TV because they contain luminance signals and color information.
However, it has the disadvantages of phase distortion and unstable color. PAL has an image size of x, with a full frame rate of 25 per second. Since the phase of the color information in each line is reversed, PAL reduces color distortion problems.
D1 format is commonly used by analog cameras. Its full frame rate is 30 frames per second, the same as NTSC. Because a common standard for PCs and industrial monitors, VGA has been widely used in digital image devices. A megapixel camera is mainly applied in occasions when accurate identification is needed such as vehicle license plate recognition or facial recognition for it can provide images with exceptional details.
Because of its high number of pixels, a megapixel camera is also used in spacious areas such as parking lots or airports to provide images with a wide view.
The camera captures a megapixel image and delivers only a user-defined thumbnail to the monitor so that users can view different images by selecting on the monitor instead of physically moving the camera. Interlaced Scan Interlaced scan split a scene into even and odd fields that contain even and odd lines, respectively. When rendering the entire scene, the even field is displayed first, followed by the odd field.
The time interval between the appearance of the two fields will lead to jagged edges, especially for a moving object. Interlaced scan is mainly used in TV monitors with a lower refresh rate, which causes the screen to flicker easily. Interlaced scan can reduce flickers because the field refresh rate of the interlaced scan seems two times faster than the original frame rate. Some monitors solve jagged edges by dropping odd field and replicate the even field as the odd field. However, the vertical resolution will be cut by half.
Progressive Scan Progressive scan renders the entire scene by displaying the even and odd lines of the frame sequentially instead of by field.
Since there is no time interval between each display, the problem of jagged edges when displaying moving objects is eliminated. Progressive scan is thus replacing interlaced scan and will become the mainstream scan technology. WDR Wide Dynamic Range technology can ensure an identifiable image of all objects under such conditions by appropriately exposing the entire scene, both the darkest and brightest parts. A lens can fit in with a smaller sensor.
Through this book, system integrators will know the benefits of IP surveillance technologies and how to maximise their investment in IP surveillance.
As we enter the new year, continuing change is a safe prediction for any fast-moving, technology-driven marketplace. Recent history confirms the ability of the security industry to shift and adapt to changing conditions and to provide an ever-expanding menu of technology solutions to make the world a safer place.
Given that the new year will bring change, what will that change encompass? More to the point, what should it encompass?
The second most popular was trends in perimeter security technology. Thanks to everyone who contributed to Expert Panel Roundtable in including the quotable panelists named and linked below. The pandemic has impacted security in many ways, some we are just now realising" What are the positive and negative effects of COVID to security?
On the negative side, integrators were limited in their ability to access customer locations, posing significant challenges to supporting customers. Innovation was also halted in many sectors — such as AI and edge computing in healthcare.
However, the pandemic increased awareness regarding the need for smart solutions that can aid in these types of crises. Smart video solutions have been identified repeatedly in the media as a potential pathway to better customer experience and increased safety. Reducing false alarms What are the latest trends in perimeter security technology? In light of that, many systems now include alarm validation that can confirm an alarm event using a camera.
The utilisation of AI-based technologies can further validate the accuracy of the alarm, making it as accurate and precise as possible. I anticipate seeing more cross-technological integrations to reduce false alarms, so that personnel in an alarm center spend as little time as possible in validating an alarm.
What will be the biggest security trends in ? There will be increased deployment in edge devices, including cameras, thermographic cameras, radar and LIDAR sensors, entry point readers, etc. Additional algorithms will be developed, greatly expanding the use and function as video surveillance transitions from a forensic tool to real-time analytics.
This increases the value of these systems and helps create ROI cases for their deployment. COVID has put a hold on in-person meetings, trade shows, etc. Virtually recreating these personal touchpoints, while cultivating and strengthening internal and external relationships, will continue to be both a challenge and opportunity for the security industry. Investments in tools and platforms to drive digital interactions have accelerated. What are the challenges and benefits of mobile access control?
Millions discover their favorite reads on issuu every month. Give your content the digital home it deserves. Get it to any device in seconds. The longer the key, the more difficult it is to crack, and the higher security it offers. WPA provides data protection via user authentication, encryption and packet inspection. It also improves wireless network management.
WPA2 indicates compliance with an advanced protocol that implements the full standard. By connecting a PoE-supported camera to a PoE switch, you need not deploy additional power cables Figure 4.
A PoE switch can provide 48 volts of direct current over two out of four pairs on an Ethernet cable, with maximum current of mA and maximum output power of Two major types of housing are vandal-proof and weather-proof housing. A vandal-proof housing features a robust design made of metal or polycarbonate plastic and can resist a violent impact force.
In extremely warm or cold environments such as in the desert or in snowy weather, a housing with a built-in heater and fan will be needed to ensure constant camera operation. A weather-proof housing should conform to the IP rating that defines protection against solid objects and liquid on a six and eight scale respectively.
Generally, a housing should be at least IPrated to provide sufficient protection for camera components. Different types of mounting can also provide different level of protection for cameras. Tamper-resistant mounting is used to prevent ill-intentioned disassembly, enabling cameras to operate in high-risk public environments.
The covering is fixed from the inside using tamper-proof mounting screws. With the scanner, a fixed network camera can change shooting direction, providing wider coverage.
Figure 6. In the case of recording for 30 consecutive days, 8 hours per day, you should prepare at least A network camera is equipped with an embedded flash memory or DRAM as a buffer zone that enables temporary storage of pre- and post-event video images.
Images are stored in the buffer zone for a short period of time before being transmitted to the back-end recording platform. They are designed for pre- and post-event storage and data portability. Images are transmitted from a camera to a host PC via Ethernet cables and stored directly in the hard disk drive of the PC. DAS is aimed to enable storage and playback on the same PC and is mainly used by small- or mediumsized businesses. Images are transmitted to a purpose-built NAS server via Ethernet cables for storage.
NAS allows storage and playback on different platforms and is especially suitable for enterprises that need to access and share largevolume data. Images are sent to a purpose-built SAN server via an exclusive fiber optic cable for storage. As with NAS, storage and playback of images can be performed on different platforms, but SAN further reduces Ethernet bandwidth usage and offers a faster transfer rate. When the trunk cable is out of order, system will switch over to the redundant cable to avoid system downtime.
Data can be spanned over multiple disk drives under one system. If one of the drives cracks, the data can still be recovered. The only difference between RAID and a hard disk drive is their array structure. With RAID 0, data is split into several segments and written to individual hard disk drives sequentially. For example, k data is split into four 64k segments and written to four hard disk drives.
However, if one of the hard disks cracks or if any problem occurs, all data will be destroyed. RAID 1 writes data simultaneously into two disk drives, one with the original data and the other with the duplicated copy. When one of the disk drives is out of order, users can still retrieve data from the other drive.
RAID 1 offers faster reading speed and better data; however, an additional drive must be added to store replicated data, thereby increasing installation costs. RAID 5 consists ists of at least three hard disk drives. The parity is used for data recovery. However, its writing speed is slower since at least two hard disk drives are needed when writing data one for storing data, the other for storing parity and its data security is more inferior. Table 6.
Apart from network cameras, a successful IP surveillance system must include powerful central management software to achieve reliability, flexibility, scalability and high efficiency. Video management software provides basic monitoring, recording and management function as well as advanced functions such as intelligent surveillance and integration with other systems.
Before the installation, users have to figure out the system requirements such as CPU capability and operating system so as to achieve the expected performance. Since it is easier for users to operate, upgrade, integrate, most large organizations, institutes, or enterprises build up their surveillance systems by adopting PC-based platforms, integrated with IT or MIS management.
As a result, many advantages such as scalability, integration, and flexibility are all included. Figure 7. Then, users may quickly connect their network cameras over the Intranet or Internet without any other advanced settings. Therefore, you can enjoy all the benefits without any additional investment. It functions as a DVR with a network interface for the connection of a set of network cameras.
However, unlike PC-based, an NVR does not allow changing or upgrading components, nor does it allow for the installation of additional applications. Due to limited scalability and compatibility, this platform is widely adopted in small- and medium-sized surveillance systems. Retail Store. Webbased software is built in the camera, allowing users to perform basic functions such as recording, monitoring and configurations.
Relatively, central management software offers more powerful functions such as playback, remote monitoring in multiple monitors etc. More than one users can access the camera to view the images at the same time. On-schedule or event-triggered recording is highly needed because the storage requirements will be reduced; so is the bandwidth. Therefore, users can set the system to use a lower frame rate during live monitoring for low bandwidth usage while shifting to a full frame rate during event-triggered recording to ensure good image quality Figure 7.
The recorded database can also be searched in a more efficient way such as by date, time, region or event. When an incident occurs, the related camera will be marked and the user can immediately switch to the images of that camera Figure 7. It is usually installed by the window to detect glass window breaking caused by burglary.
When the infrared beam is blocked, alerting signals will be sent. It is usually used for outdoor applications. Mainly used for fire detection, the sensor sends out alerting signals when the concentration of the dusts exceeds a given value.
It is ideal for indoor use. Network cameras are being used in a variety of industries, from professional to personal applications. As each industry has different demand for surveillance, their requirements for network camera types and functions vary.
This chapter presents major network camera applications along with useful tips for selecting the right kind of cameras. Professional applications require more advanced features to cope with the high demands they face. For SMB applications, surveillance systems featuring basic monitoring and management functions can meet most of the needs.
In home applications, IP surveillance systems are used not only for home security but also for keeping track of the activities in the home when parents are away from home. With a 3G phone, anyone can be kept updated with the latest traffic information, status in the office or activities in the home.
Apart from security, new applications are emerging. Such robots can also carry out investigation in dangerous areas to avoid possible harm to human lives. Entertainment is another application with increasing importance. The following table lists the main placement of network cameras and provides some recommended features for each application.
The map gives you an overview of the installation site and helps you have an in-depth discussion with your customers. You can have a more general idea about the number of cameras the whole system needs, cabling scheme, and other peripherals such as speakers, microphones, and joysticks required so as to achieve an efficient installation. Generally, cameras are used for viewing or recording, or both of them. For special requirements such as object tracking, people counting, motion detection or plate identification, intelligent capability in cameras or software will be needed.
The shooting direction determines the lens and camera types, placement, or even the coverage of a camera. Sometimes people may feel uneasy with the cameras pointing at them; in this case, you may choose cameras with a smoke cover. A camera with zoom capability is needed if you want to capture close-up images of an object at a distant. The zoom time will determine how close you need. A vari-focal lens offers a small zoom capability, which is adjusted manually via a controller.
If the monitored area is a wide open field, a camera with PTZ movement or a wide angle lens is highly recommended. PTZ cameras can instantly move to a position you want to see by a click on browser or software.
A wide angle lens may offer extensive coverage of depth-of-view, but suffer barrel distortion. In case of monitoring a fast moving object such as vehicles, it is highly suggested to use a camera with a progressive scan CCD sensor.
Progressive technology can help you generate clear-cut images without jagged edges; but the interlaced technology happens. Since customers tend to expect to keep the existing analogue CCTV cameras for the sake of lowering investments, you may adopt a video server to help them easily migrate to IP surveillance.
Outdoor applications for network cameras usually require the features of vandal- and weather-proof, and conformation to the IPrated standard for protection against vandalism or weather damage. Furthermore, to cope with very harsh temperature environments, a fan and heater is a must. In addition, the cameras should have an auto-iris lens to protect them from damage caused by strong sunlight.
The quality of the captured image is significantly influenced by light sources in the monitored area. For outdoor applications where light changes significantly during daytime and nighttime, the true day and night function camera with a removable IR-cut filter together with IR illuminators is required so as to maintain good image quality constantly for 24 hours.
A camera with better light sensitivity low light performance indicates that it can generate acceptable image quality in low-lux environments. For such high contrast places as entrances, ATMs and loading areas, cameras with WDR can still cope with the challenging light to generate identifiable image with ease.
After deciding the shooting direction and the height for camera placement, you must find a suitable mounting kit for places such as walls, ceilings, poles, roofs or corners to have your camera installed. You should check if there are power outlets nearby the locations of the cameras for easy access. If it is a concern, a network camera featuring PoE or the addition of a set of PoE kit will easily help you solve this problem that analogue camera cannot.
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