Vivotek NR7401 User manual

Vivotek NR7401 User manual
Welcome to
Planet VIVOTEK
About VIVOTEK:
VIVOTEK Inc., founded in 2000, has quickly taken its place as a leading manufacturer
in the IP surveillance industry. VIVOTEK specializes in the integration of audio-visual
components into network operation. Using sophisticated codec technologies, VIVOTEK's
innovative R&D team develops a wide range of multimedia communication products.
In 2006, VIVOTEK became a publicly traded company in the Taiwan Stock Exchange
offering sales, support, and other services in over 70 countries through a wide network of
distributors and system integrators.
Table of Contents
Chap.1 IP Surveillance Overview
01
1.1
Overview
01
1.2
Network Cameras
01
1.2.1 Introduction
01
1.2.2 Camera Types
03
1.3
Video Servers
04
1.4
Network Video Recorders
05
1.5
Central Management Software
05
1.6 Evolution of Video Surveillance
06
Chap.2 Lens and Image Sensor Technology
07
07
2.1 Lens
2.1.1 Focal Length
07
2.1.2 Iris
08
2.1.3 Lens Mount Types
09
2.2 Image Sensor
11
2.2.1 Sensor Types
11
2.2.2 Resolutions
11
2.2.3 Sensor Scan Modes
13
2.2.4 Wide Dynamic Range
14
2.3 Lens and Image Sensor Considerations
14
2.3.1 Lens Form Factors for Image Sensor
14
2.3.2 View Angle
15
2.3.3 Day and Night
15
Chap.3 Video and Audio Compression
19
19
3.1 Video Compression
3.1.1 MJPEG
19
3.1.2 MPEG-4
20
3.1.3 H.264
21
3.2 Audio Compression
22
3.2.1 G.711
22
3.2.2 AMR
22
3.3.3 AAC
22
3.3 Video and Audio Streaming
23
3.3.1 Multiple Streams
23
3.3.2 Two-way Audio
23
Table of Contents
Chap.4 IP Network
25
4.1 Network Types
25
4.2 Network Devices
25
4.3 IP Address
26
4.4 Network Protocols
27
4.4.1 Device Connection
27
4.4.2 Transmission Protocols
30
4.4.3 Video Transmission Methods
30
4.4.4 Event Notification
31
4.4.5 Timing Correction
31
4.4.6 Video Quality Control
31
4.5 Wireless Networks
32
4.5.1 WiFi
32
4.5.2 3GPP
32
4.5.3 WiMAX
32
4.6 Security
33
4.6.1 IP Filtering
33
4.6.2 Username and Password
33
4.6.3 Security Protocols
33
4.6.4 Security Wireless Transmission
34
4.7 PoE
35
Chap.5 Camera Housing and Mounting
37
37
5.1 Housing
5.1.1 Vandal-proof
37
5.1.2 Weather-proof
37
5.1.3 Covering
38
5.2 Mounting 39
5.3 Scanner
40
Chap.6 Bandwidth and Storage
41
41
6.1 Bandwidth Management
6.1.1 Assessing Demands
41
6.1.2 Calculation
41
6.2 Storage
41
6.2.1 Assessing Demands
41
6.2.2 Storage Media
42
6.3 Redundancy
43
6.3.1 Cables
43
6.3.2 RAID
43
Table of Contents
Chap.7 Video Management
45
45
7.1 Video Management Platforms
7.1.1 PC-based
45
7.1.2 NVR-based
46
7.2 Basic Features of Software
47
7.2.1 Monitoring
47
7.2.2 Recording
48
7.2.3 Playback
48
7.2.4 Management
49
7.3 Advanced Features
49
7.3.1 E-map
49
7.3.2 Auto-backup 49
7.3.3 Failure Report
49
7.4 Digital I/O Devices
49
7.4.1 Digitial Input Devices
49
7.4.2 Digital Output Devices 50
7.5 Managing Large Systems
50
Chap.8
Applications 51
Chap.9
System Design
53
9.1 Identifying Customer Needs
53
9.1.1 Viewing Considerations
53
9.1.2 Environmental Considerations
54
9.2 System Planning
58
9.2.1 Camera Considerations
58
9.2.2 Hardware Considerations
58
9.2.3 Software Considerations
58
9.3 Installation and Checks
58
9.3.1 On-site Installation
58
9.3.2 Post-installation Checks 58
9.4 Operational Training
59
9.5 System Maintenance
60
Chap.10
Intelligent Video Systems
61
10.1 Introduction
61
10.2 Architecture
61
10.2.1 Centralized Platform 61
10.2.2 Distributed Platform 62
10.3 Advantages of Distributed Architecture
63
10.4 Detection
63
10.4.1 Tamper Detection
63
10.4.2 Intelligent Motion Detection
64
10.4.3 Loitering Detection
65
10.4.4 License Plate Recognition
65
10.4.5 People Counting
Glossary
66
67
Chap.1 IP Surveillance Overview
Chap.1
IP Surveillance Overview
1.1 Overview
Increasing penetration of the Internet and the development of innovative technologies have encouraged rapid
growth of the IP surveillance industry, driving changes in the video surveillance market. It is expected that IP
surveillance will be dominating the video surveillance market in the near future, with network cameras and video
servers being major trends.
An IP surveillance digitizes video streams and transmits them over networks, allowing users to view and manage
the video and images remotely with a networked device, such as a PC, anytime and anywhere. Key components
of an IP surveillance system consist of network cameras, video servers, network video recorders and central
management software. VIVOTEK provides a full range of products mentioned above to help customers build a
reliable and high performance IP surveillance system that meets their needs.
IP surveillance products are being used in a variety of application fields, which generally fall into the following four
categories:
● Professional applications: transportation, government, industrial, construction, health care, etc.
● SMB applications: banking, education, retailing, recreation, etc.
● Home applications: residential surveillance, digital home, etc.
● 3GPP applications: mobile surveillance, elder care, baby or pet viewing, etc.
1.2 Network Cameras
1.2.1 Introduction
A network camera, also known as Internet camera, IP camera or Internet video camera, transmits live digital video
over an Ethernet network to back-end devices such as a PC or 3G phone. With a dedicated IP address, a built-in
web server and audio/video streaming protocols, it can work independently for real-time monitoring.
Images from network cameras can be viewed with a web browser such as Internet Explore, Firefox, Mozilla and
Opera, enabling customers to perform live viewing on different networked devices. In addition, customers can
control and manage multiple cameras at the same time in any places where network connection is available.
Therefore, an IP surveillance system is easier and more convenient to use compared with a CCTV system.
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Chap.1 IP Surveillance Overview
Router
Figure 1.1 Network camera connection
A network camera mainly consists of a lens, an image sensor, an image processor, a video compression SoC
(System on Chip) and an Ethernet chip that offers network connectivity for data transmission (Figure 1.2).
Lens
Image
Sensor
DSP for Image
Processing
SoC for
Video/audio
Compression
Flash
ROM
WLAN or
Ethernet/PoE
LAN/Internet
DRAM
Figure 1.2 Network camera composition
When light passes through the lens to the sensor, it is converted to digital signals and then processed by a built-in
digital signal processor. The processed video data is then compressed by a multimedia SoC to achieve a smaller
data size for optimal transmission. Finally, the video images are sent through the Internet to back-end devices to
allow for viewing and storage. Apart from video compression, the SoC is built with a RISC CPU for processing
system and network data.
The general interface of a network camera includes a power cord socket, an Ethernet socket, audio I/O ports and
digital I/O ports (Figure 1.3).
Audio Out
Status LED
SD/SDHC
Card Slot
Microphone In
Ethernet 10/100
RJ45 Socket
Indented Reset
Button
Power Cord
Socket
General I/O
Terminal Block
External/Internal
MIC Switch
Figure 1.3 General interface of network camera
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Chap.1 IP Surveillance Overview
In addition to a full-range IP surveillance product lineup, VIVOTEK has achieved competitive advantages over
other rivals in terms of multimedia SoC design, EE & ME integration and multimedia SDK. With these capabilities,
VIVOTEK is able to provide highly integrated products with superior image quality, comprehensive customer
services and versatile application solutions.
1.2.2 Camera Types
Generally, network cameras can be divided into four types for different applications, including fixed, pan/tilt/zoom,
fixed dome and speed dome.
Fixed Type
A fixed network camera points in a fixed direction to monitor a specific area, such as hallways, staircases or
corridors. Because people can be aware of the camera’s shooting direction, in some cases, it can deter vandalism
and crimes.
A fixed network camera usually comes with a RS-232/422/485 interface that connects the cameras to a pan/tilt
scanner for wider coverage.
Many fixed network cameras has exchangeable C/CS-mount lens design, giving users the ability to change the
lens to adapt for different monitoring conditions. For more information on C/CS-mount, please refer to Chapter 2.
Figure 1.4 Fixed network camera
Pan/Tilt/Zoom Type
Capable of changing shooting direction horizontally and vertically to achieve a wide field of view, a pan/tilt network
camera is used in many spacious areas, such as lobbies or parking lots.
Some pan/tilt network cameras are integrated with zoom capability so as to provide close-up images of distant
objects. Users can easily control PTZ functions through a web browser.
Figure 1.5 PTZ network camera
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Chap.1 IP Surveillance Overview
Fixed Dome Type
A fixed dome network camera, mostly designed for indoor surveillance, has a housing to make the object of
interest less aware of where the camera is pointing at. With a 3-axis mechanism, images can remain in an upright
orientation when it is installed either against the wall or on the ceiling. 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.
Figure 1.6 Fixed dome network camera
Speed Dome Type
Compared with fixed dome type, a speed dome network camera is integrated with pan, tilt and zoom capabilities,
enabling a far greater field of view. With a high zoom capability, image stabilization and 360-degree endless pan, a
speed dome camera is mainly used for professional applications, such as airports, banks or city security.
Figure 1.7 Speed dome network camera
1.3 Video Servers
A video server is a device that converts analog signals to digital, allowing users to migrate to a digital surveillance
system without replacing existing CCTV systems.
A video server mainly includes a compression chip and an Ethernet chip, with two main types available: one port or
four ports.
Figure 1.8 Video server
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Chap.1 IP Surveillance Overview
1.4 Network Video Recorders
An NVR (Network Video Recorder) is an IP-based recorder that operates independently from a PC or other
operation systems. 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.
VIVOTEK’s NR7401 helps you build a high-efficiency surveillance system, where you can simultaneously record,
monitor and manage video data through the Internet. NR7401 works seamlessly with all VIVOTEK network
cameras.
Figure 1.9 Network video recorder
1.5 Central Management Software
Central management software, often provided by the camera vendors or individual software vendors, enables
customers to manage and control cameras from remote site. Typically, central management software is windowsbased, 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.
VIVOTEK ST7501 central management software works seamlessly with VIVOTEK’s full-range network cameras
and video servers, helping customers establish a robust, flexible and efficient platform for centralized video
management.
Figure 1.10 Central management software
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Chap.1 IP Surveillance Overview
1.6 Evolution of Video Surveillance
For two decades of evolution, video surveillance has progressed from fully analog to fully digital. The development
of surveillance systems is segmented into three periods, known as the first, second and third generation.
The first-generation surveillance system consists of the use of analog CCTV cameras, multiplexers, analog
monitors and VCRs. 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 1990s 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. The replacement
of VCRs by DVRs gives users more flexibility in data viewing and storage. Around 2005, demand for networkenabled DVR picked up, and pure network-enabled NVRs were introduced. NVRs provide remote data access and
management capability.
The third-generation surveillance system, also known as IP surveillance, appeared in early 2000. The surveillance
system uses network cameras and takes full advantage of the TCP/IP Internet. Users can remotely control, monitor
and record live video (Figure 1.11).
LAN
LAN
Internet
LAN
NVR
VIVOTEK Network
Video Recorder
VIVOTEK Network Camera
PC with Video
Management Software
LAN
Audio
Coaxial Cable
Out Audio
video
In
VS7100
Analog
Camera
LAN
Audio
Coaxial Cable
Analog
Camera
video
Out Audio
In
VS7100
VIVOTEK Video Server
Figure 1.11 IP surveillance system architecture
Advantages of IP Surveillance
● Remote monitoring/storage
Since video data can be transmitted to remote networked devices over Ethernet networks, users can view camera
images in any place where IP network connection is available.
● Cost efficiency
Video surveillance systems can leverage existing IP network infrastructure, significantly reducing overall installation
costs.
● High scalability
Adding new network cameras or other networked devices in an IP surveillance system is easy by simply connecting
them to a router.
● Superior image quality
Network cameras provide high image quality; many of them even offer megapixel resolutions. In addition, IP
surveillance has no signal degradation problems during transmission, and thus can ensure steady image quality.
6
Chap.2 Lens and Image Sensor Technology
Chap.2
Lens and Image Sensor Technology
2.1 Lens
The generation of a high quality image is decided by many factors including light source of the environment, lens,
sensor, compression engine, etc. 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 the security industry, because the use of camera differs,
especially fixed type with C/CS mount, system installers themselves have to select and purchase a lens fitting their
specific needs.
2.1.1 Focal Length
Focal length is the distance between the sensor and secondary principal point of the lens.
Backward Principal Point
Focal Point/
Image Sensor
Forward Principal Point
Focal Length
Figure 2.1 Focal length
The shorter the focal length, the wider field of view it offers and higher level of distortion it may cause. In contrast,
the longer the focal length, the smaller viewing angle and field of object it has.
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Chap.2 Lens and Image Sensor Technology
Figure 2.2 shows image distortion caused by a shorter focal length and the telephoto effect resulting from a longer
focal length.
(a)
(b)
(c)
Figure 2.2 Comparison of images with (a) wide (b) normal (c) tele focal length
Lenses include the following types:
• Fixed lens: the focal length cannot be changed.
• Vari-focal lens: the focal length (field of view) can be manually adjusted;. The most common vari-focal lens is 3.5 - 8 mm.
• Zoom lens: a kind of vari-focal lens with motorized mechanism to adjust its focal length. Generally, AF (Auto Focus) algorithm is used to focus automatically.
Tele/Wide
Focus
Fixed lens
Vari-focal lens
Figure 2.3 Fixed and vari-focal lenses
2.1.2 Iris
Iris can control the amount of light entering the lens during exposure. Iris is one of the most important elements for
light sensitivity, along with aperture, shutter time, sensor, and gain.
Iris
Figure 2.4 Iris in contrast to eye pupil
8
Chap.2 Lens and Image Sensor Technology
Iris is measured in F-number, which is the ratio of the focal length to the lens diameter. 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 2.6).
f/1.4
f/2
f/2.8
f/4
f/5.6
f/8
Figure 2.5 Relationship between F-number and aperture
F-number
1.4
2
2.8
4
5.6
8
Exposure ratio
32
16
8
4
2
1
Figure 2.6 F-number and corresponding exposure ratio
Iris includes the following types in terms of control methods:
Manual-iris
Manual-iris is adjusted with a ring on the lens. 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.
• Video-drive iris: video signal is transmitted to a drive circuit in the lens and converted to currents to control the iris motor. Because the amplifier circuit is built in the lens, a Video-drive iris lens is more expensive.
• DC-drive iris: the iris is controlled by DC currents. Due to the drive circuit is integrated in the camera instead of in the lens, DC-drive iris lens features lower costs.
2.1.3 Lens Mount Types
C- and CS-mount are two major lens mount standards developed for the purpose of changing lens. The main
difference between C/CS-mount lenses lies in the flange focal distance. The flange focal distance for a CS-mount
lens is 12.5mm while 17.526mm for a C-mount lens (Figure 2.7). A CS-mount lens has higher cost efficiency and
smaller size because fewer glass components are used.
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Chap.2 Lens and Image Sensor Technology
C-mount
Lens
CS-mount
Lens
12.5 mm
17.526 mm
Sensor
Sensor
C-mount Camera
CS-mount Camera
Figure 2.7 Comparison of focal distance for C/CS-mount lenses
Note that a C-mount lens can be used on a CS-mount camera by adding a 5 mm spacer (C/CS adapter ring), but a
CS-mount lens cannot.
C-mount
Lens
C-mount
Lens
Adapter Ring
12.5 mm
12.5 mm
Sensor
CS-mount Camera
5.026 mm
Sensor
CS-mount Camera
Figure 2.8 CS-mount camera with C-mount lens using adapter ring
VIVOTEK’s IP7161 can fit in with either a CS-mount or C-mount lens by only adjusting an adjustment ring (Figure
2.9). The innovative method improves lens compatibility and installation.
IP7161
C/CS-mount
Lens
IP7161
C/CS-mount
Lens
CS-mount
Exterior View
C-mount
Interior View
Figure 2.9 Operation of VIVOTEK IP7161’s adjustment ring
10
Chap.2 Lens and Image Sensor Technology
2.2 Image Sensor
An image sensor plays a key role in converting lights through the lens into electrical signals. Based on the
manufacturing process, there are two types of sensors: CMOS (Complementary Metal Oxide Semiconductor) and
CCD (Charge-coupled Device).
2.2.1 Sensor Types
CMOS
CMOS is a standardized and constantly developing manufacturing process used in the semiconductors industry.
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.
CCD
CCD is a manufacturing process specially developed for digital imaging. 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 2.1 Comparison of features and environments for CMOS and CCD
CMOS
Features
 No artifacts, smear, or


Environment
2.2.2 Resolutions
blooming
Low power consumption
Low cost
Widely used in indoor
CCD
 High light sensitivity
 High color saturation
 Low noise in low Lux
Widely used in outdoor
Resolution refers to the number of pixels in a horizontal row and vertical column of an image. For example, a
resolution of 1280x1024 means the horizontal row consists of 1280 pixels and the vertical column includes 1024
lines. The resolution of the entire image is thus around 1.3 megapixel pixels. The higher the resolution, the more
information can be rendered, and thus the better image quality.
In traditional CCTV systems, the maximum resolution is 720x480 for NTSC (National Television System
Committee) and 720x576 for PAL (Phase Alternating Line).The most commonly used resolution is 704x480
NTSC/704x576 PAL.
NTSC
As the world’s first color TV broadcast standard, NTSC was developed by National Television System Committee
in 1953. With an image size of 704x480 and up to 30 frames per second, NTSC is mainly adopted in the United
States, Canada and Japan that uses 60Hz AC electricity.
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
1967 saw the development of a new color encoding standard for TV broadcasting in Germany, known as PAL,
which was exclusively developed for the 50Hz AC electricity used in Europe. PAL has an image size of 704x576,
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.
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Chap.2 Lens and Image Sensor Technology
D1
D1 format, also known as SMPTE 259M, is a digital image format developed by SMPTE Engineering Committee
in 1986, and is used in tape recorders. In the NTSC system, D1 has an image size of 720x480, with maximum 30
frames per second; in the PAL system, D1 image size is 720x576, with maximum 25 frames per second. D1 format
is commonly used by analog cameras.
CIF
CIF (Common Intermediate Format), frequently used in video conferencing, appeared for the first time in the ITU-T
H.261 recommendation in 1990. CIF image size is 352x288, equal to 1/4 of a PAL image. Its full frame rate is 30
frames per second, the same as NTSC.
QCIF
176x144
QCIF
176x120
CIF
352x288
CIF
352x240
4CIF
704x576
4CIF
704x480
D1
720x576
D1
720x480
(a)
(b)
Figure 2.10 CIF for (a) NTSC and (b) PAL
VGA
VGA (Video Graphics Array) format was defined by IBM in 1987, with an image size of 640x480. Because a
common standard for PCs and industrial monitors, VGA has been widely used in digital image devices. IBM has
extended the VGA standard further into 1024x768 XGA (Extended Graphics Array) and 1600x1200 UGA (Ultra
Graphics Array).
640x480
1280x1024
1920x1080
Figure 2.11 Comparison of image sizes for VGA, 1.3 MP and 2 MP
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Chap.2 Lens and Image Sensor Technology
Megapixel
A megapixel network camera features a resolution at least three times larger than that of an analog CCTV camera.
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 megapixel sensor has contributed to a new breed of non-mechanical PTZ cameras, known as digital PTZ
cameras. 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.
2.2.3 Sensor Scan Modes
Image sensor scan modes include interlaced and progressive scan.
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.
Capture
Display
Interlaced Scan
Odd Field
Even Field
1 Frame
Progressive Scan
1 Frame
Interlaced Scan
Progressive Scan
Figure 2.12 Progressive scan eliminates jagged edge artifacts of interlaced scan
13
Chap.2 Lens and Image Sensor Technology
With the refresh rate of a LCD monitors and a LCD TV enhancing to the same level of human eyes, there is no
need to use interlaced scan to reduce screen flickers. Progressive scan is thus replacing interlaced scan and will
become the mainstream scan technology.
2.2.4 Wide Dynamic Range
When shooting in high contrast, backlight, glare and light reflection environments such as the entrance, ATM or the
window side, the object will appear dark and unrecognizable. 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. VIVOTEK’s award-winning IP7142 and FD7141 support WDR, enabling the camera to
cope with challenging light conditions.
(a)
(b)
Figure 2.13 Image quality (a) without WDR and (b) with WDR
2.3 Lens and Image Sensor Considerations
2.3.1 Lens Form Factors for Image Sensor
Sensor sizes are specified by the diagonal and mainly include 1/4", 1/3”, and 1/2". A lens can fit in with a smaller
sensor. When using with a larger-sized sensor, for example, a 1/4” lens with a 1/3” sensor, the situation of dark
corners in the image will be caused.
6.4 mm
4.8 mm
3.6 mm
1/4”
1/3”
1/3” Sensor
1/2”
1/3”
4.8 mm
3.6 mm
2.7 mm
1/3”
1/4” lens
1/3”
1/3” lens
Figure 2.14 Sensor size and comparative lens size
14
1/3”
1/2” lens
Chap.2 Lens and Image Sensor Technology
2.3.2 View Angle
View angle is determined by the focal length of the lens and the sensor size. The shorter the focal length (Figure 2.15)
and the larger the sensor size (Table 2.2), the wider the view angle.
f=4
f= 8
Figure 2.15 View angle for different focal length with same sensor size
Table 2.2 View angle for different focal length with (a) 1/4” and (b) 1/3” sensors
Focal length
4 mm
6 mm
8 mm
12 mm
Vertical view angle
48∘
33∘
25∘
17∘
Horizontal view angle
37∘
25∘
19∘
12∘
Diagonal view angle
58∘
41∘
31∘
21∘
6 mm
8 mm
12 mm
(a)
Focal length
4 mm
Horizontal view angle
61∘
43∘
33∘
22∘
Vertical view angle
48∘
33∘
25∘
17∘
Diagonal view angle
73∘
53∘
41∘
28∘
(b)
2.3.3 Day and Night
Infrared light has a different wavelength from visible light, leading to jagged and blurred images. The day and night
functionality can reduce the influence of infrared light on image quality and can be achieved by using an IR-cut filter
removable and IR-corrected lens. During the daytime with sufficient illumination, infrared light is blocked to avoid
color shift. During the night, infrared light can be utilized to enhance cameras’ night vision so as to maintain good
image quality.
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Chap.2 Lens and Image Sensor Technology
ICR
An ICR (IR-cut Filter Removable) is a mechanical shutter design. It is placed between the lens and the image
sensor and is controlled by a motor or an electromagnet (Figure 2.16).
Figure 2.16 Placement of ICR
When the ICR is switched on, it will block infrared light and allow only visible light to pass through. When the ICR is
switched off, infrared light will be allowed and images will turn into black-and-white mode, which is more sensitive
to infrared light (Figure 2.17).
Ultraviolet
Visible Light
invisible
Infrared
invisible
Wave Length (nm)
100
380
770
1000
Day
Light Transmission
Wave Length (nm)
100
380
770
1000
380
770
1000
Night
Light Transmission
Wave Length (nm)
100
Figure 2.17 Operation of ICR in daytime and nighttime
16
Chap.2 Lens and Image Sensor Technology
IR Coating
Another way to block infrared light is to apply a coating on the lens; however, this will reduce light sensitivity of the
lens in nighttimes.
IR Corrected
When the network camera is used on the visible light and infrared light, it is suggested to use an IR corrected lens
with special optical design or materials to focus the visible light and infrared light on the same point (Figure 2.18).
Non-IR Corrected Lens
IR Corrected Lens
Visible Light
Visible Light & Infrared
Infrared
Figure 2.18 Focusing of visible and infrared light with non-IR and IR corrected lenses
In the daytime, images generated by an IR corrected and a Non-IR corrected lens are of identical quality (Figure 2.19.
a). During the night, images generated by a Non-IR corrected lens become blurred, while those by an IR corrected
lens remain clear (Figure 2.19. b).
IR corrected Lens
IR corrected lens
(a)
(b)
Non-IR corrected lens
Non-IR corrected lens
Figure 2.19 Image quality by IR-corrected and non-IR-corrected lenses in (a) daytime and (b) nighttime
17
Chap.2 Lens and Image Sensor Technology
IR LEDs
To get a clear image under poor-light environments, purchasing additional IR LED accessories or choosing network
cameras with built-in IR LEDs will be required.
18
Chap.3 Video and Audio Compression
Chap.3
Video and Audio Compression
Compression technologies have a major impact on image quality, bandwidth usage, storage space and system
loading. A high compression ratio can significantly reduce file size, and thus cut down bandwidth usage and
storage space. However, a high compression ratio may cause a trade-off between bandwidth and image quality.
3.1 Video Compression
MJPEG, MPEG-4 and H.264 are three major video compression technologies used by the IP surveillance industry.
Each technology has a different compression ratio and is intended for different applications and purposes.
3.1.1 MJPEG
MJPEG (Motion JPEG), announced by JPEG (Joint Photographic Experts Group) in 1992 and approved by ISO in
1994, is a multimedia format that compresses each video frame separately as a JPEG image. The technology is
widely used in DSCs (Digital Still Camera) and other consumer electronics.
Technology
MJPEG compresses the entire image of each frame as a key frame, which is encoded and decoded independently
without referring to the previous or sequential frames. This results in more redundancy in image size.
Figure 3.1 shows each frame is encoded separately by MJPEG, including the motions (the man’s movement) and
the still background (the car).
Figure 3.1 MJPEG encodes each frame entirely
19
Chap.3 Video and Audio Compression
Every encoded frame is independent from the previous or sequential frame (Figure 3.2).
Compression
Transmission
Figure 3.2 MJPEG encodes each frame independently
3.1.2 MPEG-4
MPEG-4 was formed by the MPEG working group under ISO and IEC in 1998. It was developed to facilitate video
streams transmitting over the Internet and is mainly used for bandwidth-limited applications.
Technology
MPEG-4 is a video compression standard featuring more compression efficiency. Besides some key frames
that are compressed entirely, MPEG-4 finds the differences from a reference key frame, leaves out redundant
information and compresses only frame-to-frame differences. This significantly reduces file size and bandwidth
requirements.
Figure 3.3 shows MPEG-4 encodes entirely the first frame, but only differences in the second and third frames.
Figure 3.3 MPEG-4 encodes frame-to-frame differences
Figure 3.4 shows MPEG-4 finds and simply compresses the differences of two frames.
Reference
Find Difference
Compression
Transmission
Figure 3.4 MPEG-4 refers previous frame to find differences
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Chap.3 Video and Audio Compression
3.1.3 H.264
H.264 was initially developed by ITU (International Telecommunication Union) and then published by JVT, a group
combined by ITU and ISO/IEC, in 2003. H.264 is also known as MPEG-4 part 10. H.264 has a higher compression
ratio than MPEG-4, and thus can further reduce bandwidth usage.
Technology
Similar to MPEG-4, sequential and previous key frames are required during compression and decompression.
H.264 provides a more efficient method of compression with more precise motion search and prediction; however,
it requires more powerful CPU capability.
Table 3.1 shows H.264 has a higher compression ratio than MJPEG and MPEG-4, but its CPU loading ratio is also
higher than the other two formats.
Compressed file size of origin
1%
H.264
2%
MPEG-4
20%
MJPEG
0
1
2
20
100%
Figure 3.5 Compressed file size of MJPEG, MPEG-4 and H.264
Table 3.1 Comparison of MJPEG, MPEG-4 and H.264
Compressed
file size
MJPEG
MPEG-4
H.264
20%
2%
1%
Bandwidth
comparison
20
:
2
:
1
1
:
4
:
10
ratio
Encoding
CPU loading
ratio
 Local
 Moving
 Moving
 Snapshot
picture
viewing
picture
viewing
viewing
 Real-time
 Real-time
storage
Application
transmission
transmission
21
Chap.3 Video and Audio Compression
Table 3.2 shows H.264’s bandwidth requirement is lower than MJPEG and MPEG-4 at the same frame rate.
Table 3.2 Bandwidth requirements by MJPEG, MPEG-4 and H.264
Bandwidth
requirement in KByte
MJPEG
MPEG-4
H.264
CIF 30fps
302
45
27
VGA 30fps
819
123
75
1.3M 5fps
435
155
97
3.2 Audio Compression
Major audio compression technologies include G.711, AMR and AAC, which will be introduced below.
3.2.1 G.711
G.711 is a speech compression standard established by ITU in 1972, and is widely used for voice communications
in the telecom industry, where audio quality is not the first priority.
G.711 has a bit rate of 64 kbps. Audio quality of this standard is quite low because signals may suffer from a heavy
loss in digitization.
3.2.2 AMR
AMR (Adaptive Multi-Rate) was announced by 3GPP in 1998, a standard developed for mobile communications.
Its compression ratio is better than G.711 and is widely applied to 3G mobile phones.
AMR bit rate ranges from 4.75 – 12.2 kbps. It offers a higher compression ratio and suffers from a slighter loss
compared with G.711.
3.3.3 AAC
Announced in 1997, AAC (Advanced Audio Coding) is an audio compression standard based on MPEG-2. The
standard is widely used in consumer electronics.
Table 3.3 indicates AAC for music playback purposes offers higher audio quality than G.711 and AMR aimed at
voice communications.
Table 3.3 Comparison of G7.11, AMR and AAC
G.711
AMR
AAC
Sample rate (Hz)
8K
8K
8K ~96K
Bit rate (bps)
64K
4.75K~12.2K
16K~320K
General speech
3GPP speech
CD quality
Application
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Chap.3 Video and Audio Compression
3.3 Video and Audio Streaming
3.3.1 Multiple Streams
Multiple streaming allows each video stream to be delivered in a different resolution, frame rate, and image quality
for individual quality or bandwidth demands. As a result, the camera can simultaneously transmit a small image
in CIF format for real-time monitoring and a large megapixel image for storage. The CIF image can be directly
displayed on the screen without much decoding or further scaling, thereby drastically reducing CPU loading. In
addition, because different devices such as PCs and mobile phones have different requirements for image sizes,
resolutions, and frame rates, multiple streaming gives users a higher level of flexibility for dealing with camera
images on different platforms. (Figure 3.6).
176x144 MPEG-4 5fps
3G Cell phone
640x480 H.264 30fps
Desktop PC for Viewing and Storage
Network Camera
1920x1080 MJPEG 15fps
NVR for Storage
Figure 3.6 Multiple streams are sent with different configurations simultaneously
3.3.2 Two-way Audio
Generally, audio transmission methods consist of simplex, half duplex and full duplex. Unlike simplex and half
duplex, full duplex provides simultaneous communications capability, also known as two-way audio.
Simplex
Voices can be transmitted in one direction only, from the sender to the receiver. For example, only the control site
or the monitored site can make announcement; the receiver cannot make any response.
Figure 3.7 Simplex allows only unidirectional communications
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Chap.3 Video and Audio Compression
Half duplex
Voices can be transmitted in both directions, from the sender or the receiver, but only one direction at a time
(Figure 3.8).
Figure 3.8 Half duplex allows communications in one direction at a time
Full duplex
Voices can be transmitted in both directions at the same time. As in Figure 3.9, the control site can speak to and
receive voices from the monitored site. So does the monitored site.
Router
Figure 3.9 Full duplex allows communications in both directions at a time
24
Chap.4 IP Network
Chap.4
IP Network
4.1 Network Types
As the most popular LAN technology, Ethernet uses a number of wiring to build the connection between end
systems and the network. The most common type of Ethernet cables is RJ45. The original Ethernet transfer rate
was 10Mbps. With bandwidth demand increasing, higher transfer rates such as 100Mbps, 1Gbps and 10Gbps
were developed.
Currently, different Ethernet standards can be universally recognized as a form of “100BaseT”. The first number
stands for the transfer rate and the last number or character indicates the characteristics of the transmission
medium. For example, 100BaseT is 100 Mbps over network cable.
Ethernet Cable RJ45
4.2 Network Devices
Hub
A hub is a network device that connects a PC with an Ethernet cable to establish a LAN and enables the PC to
communicate with other PCs on the LAN. When data is sent from a PC to a hub, the hub will duplicate the data to
all PCs on the LAN. Only the destination PC will keep the data; other PCs will abandon the data.
Switch
A switch is a network device that serves the same purposes as hubs, but it makes more efficient use of bandwidth
resources. A switch identifies the destination of data by its MAC address and sends it to the designated PC only,
thereby reducing interference between data.
25
Chap.4 IP Network
Router
A router connects different Ethernet networks to achieve network coverage. It can connect LANs that use different
network protocols or transmission methods. When a router receives a packet, it checks the destination address of
the packet, and designates an optimal path for it based on packet size and priority.
4.3 IP Address
Each network device has its own IP address. An IP address is like a doorplate of the device, helping data to be
delivered to the correct destination. An IP address contains 32 bits, which are divided into four parts, each part
separated by a dot, such as 255.255.255.0.
The following three blocks of the IP address space are reserved for private Internets (local networks):
• 10.0.0.0~10.255.255.255
• 172.16.0.0~172.31.255.255
• 192.168.0.0~192.168.255.255
However, with the number of network devices increasing, IP address shortage has become a problem. To solve the
problem, DHCP and NAT and IPv6 were developed.
DHCP
DHCP (Dynamic Host Configuration Protocol) automatically assigns a valid IP address to a network device on the
Internet. Allocating a fixed IP address for each device will result in idle IP addresses when the devices are not in
operation. Therefore, DHCP can make more efficient use of the IP addresses.
NAT
NAT (Network Address Transfer) uses translation tables to change a private IP address of an outgoing packet
from a client PC into a public IP address. In this way, multiple PCs can access the Internet through one public IP
address.
WAN
LAN
3 Target: Public IP
4 Target: Private IP
Client A
Internet
2 Source: Public IP
Router with NAT Server
1 Source: Private IP
Client B
Figure 4.1 NAT enables multiple PCs to share one public IP address
NAT breaks the rule of one IP address for one network device. As a result, when multiple network devices are
transmitting a great deal of data simultaneously, serious delay and packet loss may occur.
26
Chap.4 IP Network
IPv6
IPv6 standard consists of 128 bits, which are divided into eight parts, each group containing four 16-bit digits and is
separated by a colon. IPv6 IP addresses are presented in a different format from IPv4, for example 3ffe:0305:0000:
0000:0000:0000:0000:0001.
Table 4.1 Comparison of IPv4 and IPv6
Feature
IPv4
IPv6
Comparison
Address space
32 bits
128 bits
Configuration setting
Manual
Auto
IPv6 doesn’t need an independent DHCP
Priority control
No
Yes
IPv6 achieves higher video quality
Authentication
No
Yes
IPv6 provides safer data transmission
IPv6 provides larger address space
4.4 Network Protocols
Protocols are a set of rules that enable applications or devices to communicate with each other, allowing data to be
transmitted and received accurately.
4.4.1 Device Connection
This section introduces two types of protocol, one for facilitating network connectivity after the device obtains a
valid IP address and the other for building connection between networking devices and the Internet. The first type
includes DNS and DDNS and the second type includes PPPoE and UPnP.
DNS
When locating a network device, you need to input a numerical IP address, which is difficult to remember. DNS
(Domain Name System) allows you to input an IP address in text format and automatically maps it to the numerical
IP address of that network device. For example, when a user inputs a registered domain name (such as www.
vivotek.com), the DNS server automatically maps the domain name to an IP address such as 203.160.252.248.
DDNS
DDNS (Dynamic DNS) automatically matches a floating IP address to a registered domain name, allowing users
without a fixed IP address to easily connect to a network device. For example, if you register a domain name as
john-1.safe100.net, and the IP address for the first time connection is 203.160.252.200; the DDNS server will
match it to john-1.safe100.net. Next time the device is online with a different IP address, such as 203.160.252.201,
the DDNS will still match it to john-1.safe100.net. In this way, users only need to remember the registered domain
name to locate your network device (Figure 4.2).
27
Chap.4 IP Network
DDNS Server
Initial Connection
2 Access Video with The
1 Submit My IP: 60.250.55.30
Same Domain Name:
john-1.safe100.net
1
2
Internet
Camera
PC
DDNS Server
Reconnection
2 Access Video with The
1 Submit Changed IP: 60.250.2.250
Same Domain Name:
john-1.safe100.net
1
2
Internet
Camera
PC
DDNS Server
Reconnection
2 Access Video with The
1 Submit Changed IP: 60.250.168.3
1
2
Same Domain Name:
john-1.safe100.net
Internet
PC
Camera
Figure 4.2 DDNS in operation
safe100.net
Figure 4.3 VIVOTEK DDNS server
28
Chap.4 IP Network
PPPoE
PPPoE (Point-to-Point Protocol over Ethernet) is a protocol that enables connections between a DSL modem and
the Internet. This service is provided by ISP (Internet Service Provider).
UPnP
UPnP (Universal Plug and Play) includes two main functions, UPnP port forwarding and UPnP presentation.
UPnP port forwarding enables network devices to easily communicate with each other over the Internet. When both
the network device and router support UPnP, video streaming ports will be forwarded, so called port forwarding
(Figure 4.4).
Camera
UPnP
Internet
PC
PC
Port Fowarding
Figure 4.4 UPnP port forwarding
If the user’s PC supports UPnP presentation, an icon of the network devices on the same LAN will appear in My
Network Places to allow for direct access (Figure 4.5).
Figure 4.5 UPnP-enabled network cameras shown in My Network Places
29
Chap.4 IP Network
4.4.2 Transmission Protocols
This section introduces two types of protocols. UDP, TCP and HTTP are underlying protocols that carries the data.
RTSP/RTP/RTCP are real-time media transmission protocols.
● Data Transmission
UDP
A UDP (User Datagram Protocol) source port sends out packets continuously and does not require the destination
port to return a confirmation message, allowing for more real-time audio and video streams. However, the packets
may be lost due to network burst traffic and images may be broken. UDP connection is mainly used for timesensitive responses and when the video quality is less important.
TCP
A TCP (Transmission Control Protocol) source port sends out packets and waits for a confirmation message from
the destination port before sending out sequential packets. If no confirmation message is received, the source port
will send that packet again. TCP guarantees the complete delivery of streaming data and thus provides better video
quality. Nevertheless, its real-time effect is inferior to UDP.
HTTP
Designed for users to view information on a web page through a browser, HTTP (Hypertext Transfer Protocol)
allows the same quality as TCP protocol without needing to open specific ports for streaming under some network
environments. Users inside a firewall can utilize this protocol to allow streaming data to come through.
● Media Transmission
RTSP
RTSP (Real Time Streaming Protocol), which consists of RTP and RTCP, is a protocol used to facilitate multimedia
streaming over the Internet. As a protocol for 3GPP streaming, RTSP enables users to access video images via a
3G phone.
4.4.3 Video Transmission Methods
Unicast
With unicast, data is transmitted to the designated PC only and other PCs on the same network will not receive
the data. If more than one PC request for the same piece of data, the source PC has to send the data repeatedly
to different destinations. This is the most popular transmission method and is also known as One-to-One
transmission.
Broadcast
Broadcast is mainly used on the LAN. Compared with unicast, all network devices in broadcast on the same
network will receive data whether they need it or not. The source PC sends data to a router where data is replicated
and sent to multiple destination PCs requesting for the same data. It is also called One-to-All transmission.
Multicast
With multicast, data is transmitted to a multicast group consisting of PCs requesting for the same data on the
Internet. Once the data reaches the multicast group, it is duplicated and delivered separately to each PC in that
group.
Multicast significantly reduces bandwidth usage and is suitable for web video applications such as VoD, e-learning
and video conferencing. It is also called One-to-Many or Many-to-Many transmission.
30
Chap.4 IP Network
4.4.4 Event Notification
SMTP
SMTP (Simple Mail Transport Protocol) is for e-mail transmission. With SMTP, e-mail can be transmitted from the
client to the mail server.
FTP
FTP (File Transfer Protocol) is for file transmission. FTP allows you to upload and download files to and from a
server. Via FTP, the user can upload information from a network camera such as snapshots or video clips to a FTP
server when an event occurs.
4.4.5 Timing Correction
NTP
NTP (Network Time Protocol) synchronizes the system time of a network device on the Internet to a reference time.
After a network device sends a request to a NTP server for time synchronization, it will receive a Greenwich Mean
Time returned from the server. NTP can solve the time difference between network cameras and other network
devices.
4.4.6 Video Quality Control
QoS
For bandwidth limitation applications, it is important to manage bandwidth allocation carefully. As part of the IEEE
802.1p standard, QoS (Quality of Service) aims to optimize bandwidth usage. QoS ensures streaming performance
at a steady level by transmitting data according to its priority and by the requests of the applications. With QoS,
bandwidth resources are used more efficiently and real-time multimedia streams can be transmitted constantly.
VIVOTEK products support QoS to allow for optimized bandwidth efficiency.
In a non-QoS environment, bandwidth is likely to be occupied by data stream, leading to jittering of other video
streams (Figure 4.6.a). In a QoS environment, since bandwidth allocation is optimized, every video stream can be
transmitted smoothly in priority (Figure 4.6.b).
Internet Packer
Data
Video/Audio
FTP Data
FTP Data
Download Data
Internet
Video /Audio
Video /Audio
Switch
(a)
Viewing Video/Audio
Internet Packer
Data
Video/Audio
FTP Data
FTP Data
Download Data
Internet
Video /Audio
Video /Audio
Switch
(b)
Viewing Video/Audio
Figure 4.6 Bandwidth allocation for (a) non-QoS, (b) QoS
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Chap.4 IP Network
4.5 Wireless Networks
Wireless technologies include WiFi, WiMAX and 3GPP. WiFi is used for short-distance transmission while WiMAX
for long distance.
4.5.1 WiFi
IEEE 802.11, developed by the IEEE LAN/MAN Standards Committee, is a set of standards for wireless local area
network computer communication. 802.11b, 802.11g, and 802.11n are widely used in wireless network devices.
802.11b
802.11b operates in the 2.4GHz band with a transfer rate of 11Mbps and a range of 35 meters indoors and 100
meters outdoors. The drawback of 802.11b is that signals can be blocked by walls. The 2.4GHz is also subject to
interference caused by electronics or Bluetooth signals.
802.11g
802.11g, the same as 802.11b, operates in the 2.4GHz band. It has a transfer rate of 54Mbps, similar to that
of 802.11a, and a range of 25 meters indoors and 75 meters outdoors. 802.11g has the same weaknesses as
802.11b; however, it outperforms 802.11b in transfer rate.
802.11n
802.11n is a wireless standard certified in 2008. Based on MIMO (Multi-input Multi-output), 802.11n boasts an
amazing transfer rate of 600Mbps and a range of 50 meters indoors and 300 meters outdoors. It can operate in
the 2.4GHz or 5GHz band and is ideal for applications demanding high bandwidth such as high-definition video
streaming.
4.5.2 3GPP
3GPP is a set of open standard protocols for audio and video bitstreams to be viewed on a 3G mobile phone (Figure
4.7). This standard is widely supported by major mobile phone vendors.
All of VIVOTEK’s 7000-series or above network cameras provide 3GPP support, allowing users to access video
images at any time and anywhere via a 3G mobile phone.
Home
Internet
3G
3G-324M
Multimedia
Gateway
3G Cell Phone
Office
Figure 4.7 Mobile surveillance via 3GPP
4.5.3 WiMAX
WiMAX is a wireless broadband technology featuring long-distance transmission capability. It is an alternative to
cable networks such as ADSL in remote areas where network infrastructure is incomplete.
WiMAX, developed by the 802.16 group of IEEE, is also called the 802.16 standard. WiMAX offers a transfer rate
of 70Mbps in a range of 70 kilometers, making it ideal for long-distance and outdoor connection. Compared with
802.11X standards, WiMAX provides wider coverage, a higher transfer rate, a larger transmission volume and
higher QoS.
32
Chap.4 IP Network
4.6 Security
Since data is likely to be intercepted during transmission, appropriate protection schemes are needed. The
following methods can protect data from security risks.
4.6.1 IP Filtering
You can confine a client’s IP address within a specific range to authorize or deny user access. A client’s IP address
in an authorized list will be able to access data while that in a denied list will be refused to access.
4.6.2 Username and Password
You can assign accounts and passwords to users so as to achieve simplified and efficient management.
VIVOTEK offers the three user privilege levels of administrator, operator and viewer; only administrators can make
configurations.
4.6.3 Security Protocols
Security protocols protect data from unauthorized access. SSL/TLS and IPSec are three basic network security
protocols. The major difference is that SSL/TLS encrypts the data and IPSec encrypts the transmission channel.
SSL/TLS
SSL (Secure Sockets Layer) encrypts data transmitting between the server and the client to ensure the
confidentiality and integrity of the data. When a client submits a request for accessing web pages, a public key is
sent to the client for data encryption. Data encrypted by the client using the pubic key can be decrypted only by the
server's private key. Due to this property of the keys, the client is able to send secure data that can be understood
only by the server. SSL can protect data from being counterfeited, intercepted or tampered and is the most
common security standard for e-commerce.
TLS (Transport Layer Security) is a standard developed on the basis of SSL for higher security, confidentiality, data
integrity and authentication.
Network Camera
Network Camera
(a)
(b)
Figure 4.8 Data transmission (a) without SSL/TLS encryption and (b) with SSL/TLS encryption
HTTPS
HTTPS is a combination of HTTP and SSL/TLS. It encrypts data at the source port and decrypts it at the
destination port. HTTPS is mainly used to protect e-commerce, asset management, e-mails or IP surveillance
systems.
33
Chap.4 IP Network
IPSec
IPSec (IP Security) is a security protocol designed to protect communications over the Internet. Incorporating
security protocols in IP architecture can ensure network communications security, even if the data is not encrypted
with SSL/TLS.
IPSec provides two functions, authentication and confidentiality. The authentication function confirms the identity
of the source and the destination PCs so as to protect data transmitting between them. The confidentiality function
encrypts the content to prevent from interception by the third party. Both authentication and confidentiality operate
on the basis of encryption (or hashing). IPSec also provides regulations on key exchange to help generate and
manage keys for encryption.
IPSec creates a secure network communications tunnel, such as VPN (Virtual Private Network). VPN builds
transmission tunnels between two nodes on the Internet, rather than using physical cables for data transmission.
IPSec
Intercepted PC
Network Device
Destination PC
Figure 4.9 Encryption of transmission tunnels with IPSec
4.6.4 Security Wireless Transmission
WEP
WEP (Wired Equivalent Privacy), also known as Wireless Equivalent Privacy, is designed to protect data on a
wireless network because data transmitted by radio wave can be easily intercepted. A key must be set in the
wireless access point and when a user connects to the access point, he has to enter the same key to connect to
the Internet. WEP can provide a security level comparable to cable networks.
WEP encrypts data from wireless access points with a shared key that contains 40 to 256 bits. The longer the key,
the more difficult it is to crack, and the higher security it offers.
WPA
With the increasing computing capability of a PC, WEP, which uses a fixed encryption key, becomes vulnerable to
be attacked. Hence, the Wi-Fi Alliance developed WPA (Wi-Fi Protected Access) /WPA2 standard based on WEP.
WPA uses TKIP (Temporal Key Integrity Protocol) that dynamically changes the key for each packet during
transmission. With a 128-bit key, WPA offers a higher level of security than WEP. 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. In addition, WPA defines the use
of AES (Advanced Encryption Standard) as an additional replacement for WEP encryption.
Figure 4.10 Encryption of data with WEP/WPA
34
Chap.4 IP Network
4.7 PoE
Conventional network cameras require a power cable for power supply and an Ethernet cable for data
transmission. PoE (Power-over-Ethernet), developed by the IEEE802.3af task force, enables power to be supplied
over the same Ethernet cable, and thus eliminates the use of power cables. By connecting a PoE-supported
camera to a PoE switch, you need not deploy additional power cables (Figure 4.11).
A PoE switch can provide 48 volts of direct current over two out of four pairs on an Ethernet cable, with maximum
current of 400mA and maximum output power of 15.4W. IEEE has developed a new IEEE 802.3at standard, known
as PoE+ to provide maximum output power of 30W.
Power
LAN
LAN
Injector
Splitter
Non-PoE Switch
LAN
Non-PoE
Network Camera
LAN
LAN
Injector
Non-PoE Switch
PoE
Network Camera
Power
LAN
LAN
Splitter
PoE Switch
LAN
Non-PoE
Network Camera
LAN
LAN
PoE Switch
PoE
Network Camera
Figure 4.11 Connection of PoE and non-PoE network cameras
35
Chap.4 IP Network
LAN
LAN
LAN
LAN
UPS
Power
Internet
PC
LAN
NR7401 with Built-in PoE Switch
Retail Store
Figure 4.12 PoE-enabled devices for retail application
36
Chap.5 Camera Housing and Mounting
Chap.5
Camera Housing and Mounting
5.1 Housing
A housing protects cameras from damages caused by vandalism or harsh environments, thereby ensuring
constant operation. Two major types of housing are vandal-proof and weather-proof housing.
5.1.1 Vandal-proof
A vandal-proof housing can resist violent attacks, enabling cameras to operate in high-risk public environments
such as prisons, transportation stations, parking lots, and ATM sites. A vandal-proof housing features a robust
design made of metal or polycarbonate plastic and can resist a violent impact force.
5.1.2 Weather-proof
A weather-proof housing protects cameras from damage caused by rain and dust, allowing cameras to be used
outdoors. 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 IP66-rated to provide sufficient protection
for camera components.
Figure 5.1 Vandal-proof housing
Figure 5.2 Weather-proof housing
37
Chap.5 Camera Housing and Mounting
Table 5.1 Degree of protection against dust represented by first digit of IP rating
Prevents device from accessing hazardous parts
0
Non-protected
1
Protected against solid foreign objects 50 mm diameter and larger
2
Protected against solid foreign objects 12.5 mm diameter and larger
3
Protected against solid foreign objects 2.5 mm diameter and larger
4
Protected against solid foreign objects 1.0 mm diameter and larger
5
Dust Protected
6
Dust-tight
Table 5.2 Degree of protection against water represented by second digit of IP rating
Prevent the damage of penetration of water into the housing
0
Non-protected
1
Protected against drips
2
Protected against drips if the housing is bent at an angle of 15°
3
Protected against spray-water
4
Protected against splash-water
5
Protected against jet-water
6
Protected against strong jet-water
7
Protected against the effects of temporary submersion in water
8
Protected against the effects of permanent submersion in water
5.1.3 Covering
The two main types of coverings are transparent and smoke. A housing with a smoke cover makes the camera’s
shooting direction invisible and can be used if people feel uneasy with the perception of the cameras pointing at
them.
38
Chap.5 Camera Housing and Mounting
5.2 Mounting
Due to demand for placing network cameras at different locations, you can choose different kinds of mounting
solutions or mounting kits to solve the difficulties you may encounter. Different types of mounting can also provide
different level of protection for cameras.
Ceiling Mount
Wall Mount
Gooseneck Wall Mount
Pole Mount
Drop-ceiling Mount
Pendant Mount
Corner Mount
Figure 5.3 Mounting methods
Tamper-resistant Mounting
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.
Figure 5.4 Tamper-proof mounting screws
39
Chap.5 Camera Housing and Mounting
5.3 Scanner
A network camera with a RS-232/422/485 interface can be connected to a pan/tilt scanner. With the scanner, a
fixed network camera can change shooting direction, providing wider coverage.
Figure 5.5 Scanner
40
Chap.6 Bandwidth and Storage
Chap.6
Bandwidth and Storage
6.1 Bandwidth Management
In order to achieve efficient video transmission, it is important to evaluate your bandwidth requirements before
setting up an IP surveillance system.
6.1.1 Assessing Demands
Bandwidth requirements vary with the following factors.
● Resolution: the higher the resolution, the more bandwidth is required
● Complexity of the scene: the more complicated the scene, the more bandwidth is required
● Compression type: the lower compression ratio, the more bandwidth is required
● Image quality: the higher image quality, the more bandwidth is required
● Frame rate: the higher frame rate, the more bandwidth is required
6.1.2 Calculation
To assess bandwidth requirements, you can use Calculator.exe to evaluate the number of packets sent. You can
download the file from http://www.vivotek.com/downloadfiles/faq/audiovideo.
6.2 Storage
Besides bandwidth assessment, your storage space is also required to be evaluated, especially with megapixel
images.
6.2.1 Assessing Demands
The following factors must be taken into account when assessing storage demand:
● The number of cameras deployed
● Recording time
● Recording criteria, such as constant, scheduled or event-triggered recording
● Other factors such as codec, image quality and frame rate
41
Chap.6 Bandwidth and Storage
Figure 6.1 will demonstrate the calculation of storage space required for one-day continuous recording with an
assumed transfer rate of 400kbps. Note that 1 byte equals 8 bits and 400Kb totals 50KB (b refers to bit and B
refers to Byte).
In the case of recording for 30 consecutive days, 8 hours per day, you should prepare at least 43.2GB (Figure 6.1).
400Kb = 50KB
1 second
50KB x 3,600 = 180MB
Store 3,600 seconds data in 1 hour
180MB x 8 = 1.44GB
Store 8 hours data in 1 day
1.44GB x 30 = 43.2GB
Store 30 days in 1 month
Figure 6.1 Calculation of storage space required for 30-day recording (400Kb)
6.2.2 Storage Media
Various types of storage media have been developed to meet different demands and purposes, such as
● Internal buffer
● External memory cards
● DAS (Direct Attached Storage)
● NAS (Network Attached Storage)
● SAN (Storage Area Network)
Internal Buffer
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.
External Memory
CF, SD and SDHC cards are three main external memory types. They are designed for pre- and post-event storage
and data portability. Many of VIVOTEK products are furnished with a SD/SDHC card slot for on-board storage.
42
Chap.6 Bandwidth and Storage
DAS
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.
NAS
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
SAN
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.
6.3 Redundancy
In a bid to avoid significant losses from network downtime and hard disk drive cracks, it is highly recommended to
plan a redundancy solution ahead, such as using back-up cables or RAID structure. 6.3.1 Cables
Additional cables can be deployed during installation for failover. When the trunk cable is out of order, system will
switch over to the redundant cable to avoid system downtime.
6.3.2 RAID
RAID (Redundant Array of Independent Disks) is an array of several hard disk drives that can be used as one
single hard disk drive. 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. Compared with a large-volume
hard disk drive, RAID provides higher reading/writing speed, stronger data integration, redundancy and processing
capability and better recovery capability.
RAID 0 (Striped)
With RAID 0, data is split into several segments and written to individual hard disk drives sequentially. For example,
256k data is split into four 64k segments and written to four hard disk drives.
RAID 0 can deliver better I/O performance and faster reading and writing speed. However, if one of the hard disks
cracks or if any problem occurs, all data will be destroyed.
RAID 1 (Mirrored)
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.
43
Chap.6 Bandwidth and Storage
RAID 5 (Parity RAID)
RAID 5 consists ists of at least three hard disk drives. Similar to RAID 1, RAID 5 stores redundant data in separate
disk drives, but in an even- and odd-parity scheme. The parity is used for data recovery.
RAID 5 is more cost-effective than RAID 1 because only one drive is used to store parity. 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. In addition, RAID 5 offers higher security than RAID 0 because
parity can be used to restore data if a drive cracks.
Table 6.1 Comparison of RAID 0, RAID1 and RAID 5
RAID
type
44
No. of hard disk
drives required
RAID 0
>2
RAID 1
2
RAID 5
>3
Total storage
space
Performance
Security
Main application
Capacity of all drives
High
Low
Users that require high
performance
Capacity of half of
the drives
Medium
High
When data security is
top priority
Capacity of total
minus one drive
Fast reading and
slow writing speed
Medium
Ensuring uncompromising
data security with limited
budget
Chap.7 Video Management
Chap.7
Video Management
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.
7.1 Video Management Platforms
There are two types of video management platforms: PC- and NVR-based.
7.1.1 PC-based
A PC-based platform is implemented by installing video management software on a PC or server, a standard
hardware component. 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.
Alarm
Network Attached
Storage
Microphone
PC
Speaker
Viewer
Administrator
Internet
Remote Access
Siren
PIR
Figure 7.1 PC-based video management platform
VIVOTEK provides application software together with the package to help users set up an IP surveillance system
with ease. From the application software, Installation Wizard 2 and PC-based central management software
ST7501 are included.
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Chap.7 Video Management
Installation Wizard 2 is the new generation of VIVOTEK’s installation software, in which the embedded intelligent
functions will guide users to set up a network camera with ease. In other words, its "smart mode" enables those
who has not much technical knowledge to be capable of installing a network camera themselves only by a few
"clicks." It can automatically detect users’ networking environments and help them get rid of some complicated
setting inputs like IP Address, DDNS, UPnP Port Forwarding, and PPPoE connecting. Then, users may quickly
connect their network cameras over the Intranet or Internet without any other advanced settings. From now on,
the Installation Wizard 2 is free bundled along with VIVOTEK’s packages. Therefore, you can enjoy all the benefits
without any additional investment.
Figure 7.2 VIVOTEK Installation Wizard 2
As for ST7501, the functionalities will be introduced in section 7.2. VIVOTEK has formed an alliance with numbers
of central management software development vendors in order to better fulfill customers' needs. For more
information, please go to Alliance page on VIVOTEK website.
7.1.2 NVR-based
An NVR is a standalone recording device, in which video management software is pre-installed, providing easy-touse interface and video management platform. 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
Alarm
Microphone
Speaker
NVR
Viewer
Internet
Remote Access
Siren
PIR
Central Station
Administrator
Figure 7.3 NVR-based video management platform
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Chap.7 Video Management
7.2 Basic Features of Software
Video management software mainly includes web-based software and central management software. 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., to achieve efficient, flexible video management.
7.2.1 Monitoring
Users can view live video images with a web browser such as Internet Explorer, on a mobile device or via software
(Figure 7.4). More than one users can access the camera to view the images at the same time.
Figure 7.4 Monitoring on different platforms
Through the management software, users can use different viewing modes like split windows to simultaneously
view the transmitted images from multiple cameras.
Figure 7.5 Dual-screen support of ST7501
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Chap.7 Video Management
7.2.2 Recording
Recording can be performed in different modes such as continuous, on schedule or on event trigger according to
their needs. On-schedule or event-triggered recording is highly needed because the storage requirements will be
reduced; so is the bandwidth.
Figure 7.6 On-schedule recording
In an IP surveillance system, the frame rate is changeable. 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 7.7).
1 second
}
Analog System
Central Station
Network Video
System
Event Trigger
Figure 7.7 Changeable frame rate of network camera
7.2.3 Playback
Recorded video images can be viewed in multiple split windows and by several users at the same time. The
recorded database can also be searched in a more efficient way such as by date, time, region or event.
Figure 7.8 Video playback
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Chap.7 Video Management
7.2.4 Management
Through the management interface of the software, users can make various configurations of video images, set up
and manage various parameters, such as recording schedule and event trigger conditions.
7.3 Advanced Features
7.3.1 E-map
The E-map functionality gives users an overview of the system and helps them quickly locate each camera. When
an incident occurs, the related camera will be marked and the user can immediately switch to the images of that
camera (Figure 7.9).
Figure 7.9 E-map improves camera management efficiency
7.3.2 Auto-backup
Auto-backup enables users to back up data regularly and automatically, providing a more reliable IP surveillance
system.
7.3.3 Failure Report
Failure reports that display a history of system errors can help users solve problems more efficiently.
7.4 Digital I/O Devices
Digital input and output ports connect network cameras to external security devices such as alarms and sensors,
strengthening the surveillance system’s detection and alerting capability.
7.4.1 Digital Input Devices
● Glass break sensor: the device can detect specific frequency of sounds and vibration, for example, glass breaking. It is usually installed by the window to detect glass window breaking caused by burglary.
● Active infrared sensor: the device emits infrared light to detect intruding objects. When the infrared beam is blocked, alerting signals will be sent. It is usually used for outdoor applications.
● Smoke sensor: the device can detect dust concentration in the air. Mainly used for fire detection, the sensor sends out alerting signals when the concentration of the dusts exceeds a given value.
● PIR (passive infrared sensor): the device can detect object movement by the infrared light emitted from the object caused by its temperature.It is ideal for indoor use.
49
Chap.7 Video Management
Glass Break Sensor
Smoke Sensor
Passive IR
Active IR
Internet
Figure 7.10 Connection of digital input devices
PC
7.4.2 Digital Output Devices
● Alarm: when incidents occur, alarms will send out high frequency of sounds to notify security staff or visitors.
● Alert light: alert lights inform the security staff of an incident with flashlight, such as xenon flashlight.
● Remote transmitting system: warning signals are to the control console to prompt more comprehensive
reaction.
Alert light
Alarm
Internet
Control Console
Figure 7.11 Connection of digital output devices
PC
7.5 Manage Large Systems
For a large surveillance system that consists of dozens or hundreds of network cameras, server/client-based
central management software is needed so as to provide flexible and scalable management. By installing server/
client software in separate PCs, users can manage cameras remotely in any places.
VIVOTEK’s central management software ST7501 features reliable recording, easy system management, and
great scalability for diverse IP surveillance applications. With server/client structure, users can carry out remote
management on a large-scale system and benefits from a robust IP surveillance system.
ST7501 Client A
ST7501 Server
Network Cameras
ST7501 Client B
Figure 7.12 VIVOTEK ST7501 central management software
50
Chap.8 Applications
Chap.8
Applications
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.
IP surveillance applications can be mainly categorized as professional, SMB (Small- and Medium-sized Business),
3GPP and home applications. 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. 3GPP
applications allow for real-time monitoring and control on the move. 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. For example, the National Taiwan University integrated
a VIVOTEK PT7135 in a robot to have it served as a guide dog for the blind. Such robots can also carry out
investigation in dangerous areas to avoid possible harm to human lives. Entertainment is another application
with increasing importance. As an example, VIVOTEK FD7131 and IP6122 were used to monitor racing pigeon
movement during contests held in Zhejiang, China. For more information, please go to Success Stories page under
the Product section on VIVOTEK website.
51
Chap.8 Applications
The following table lists the main placement of network cameras and provides some recommended
features for each application.
Camera Placement
52
Recommended Features
Large outdoor places (airports, parking
lots, parks, etc.)
Day and night, vandal-proof, IP66-rated,
pan/tilt/zoom, megapixel, intelligent,
weather-proof
Small outdoor places (building perimeter,
alleys, etc.)
Day and night, vandal-proof,
weather-proof, IP66-rated
Large indoor places (stations, halls,
stadiums, etc.)
Vandal-proof, pan/tilt/zoom, megapixel,
intelligent
Small indoor places (room, corridors,
stairway, elevators, etc.)
PoE
Control rooms
Two-way audio
Places with moving objects (highways,
train/bus stations, etc.)
Progressive scan CCD, intelligent
High contrast places (ATMs, parking lot
entrances, etc.)
WDR
Chap.9 System Design
Chap.9
System Design
9.1 Identifying Customers Needs
Before deploying an IP surveillance system, having a layout map of the site at hand to identify the shooting
purposes of each network camera is necessary and useful. 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.
9.1.1 Viewing Considerations
The following factors should be your main considerations when installing a network camera.
Viewing Direction
The shooting direction determines the lens and camera types, placement, or even the coverage of a camera. Bear
in mind that cameras’ shooting direction should be in line with the direction of illumination to minimize the influence
of backlighting on image quality. Sometimes people may feel uneasy with the cameras pointing at them; in this
case, you may choose cameras with a smoke cover.
Viewing Distance
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.
Viewing Angle
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.
Viewing Object
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.
53
Chap.9 System Design
9.1.2 Environmental Considerations
CCTV Cameras
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/Indoor
Outdoor applications for network cameras usually require the features of vandal- and weather-proof, and
conformation to the IP66-rated 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.
Light
The quality of the captured image is significantly influenced by light sources in the monitored area. For most of the
conditions you encounter, VIVOTEK provides different products to meet your specific needs as follows.
Day and Night
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.
Low Light
A camera with better light sensitivity (low light performance) indicates that it can generate acceptable image quality
in low-lux environments. VIVOTEK’s full-range cameras provide fairly good low light performance.
Challenging Light
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.
Mounting
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. VIVOTEK provides a variety
of mounting kits to facilitate your installation.
Power Outlet
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.
Wireless/Wired Connection
Wireless connection is often applied in a wide open space or where the decor requires high protection or no
Ethernet outlets provided. Without the cabling, you can greatly decrease the cost and get rid of the problem of
tangled cabling. Most of buildings now have Ethernet outlets as infrastructure, with which you can significantly
reduce the workload of cabling but the CCTV security must pay for.
Audio
When installing audio-enabled cameras, audio cables must be kept away from power cables and high-frequency
signal cables so as to reduce interference. In addition, microphones should be placed near the sound source and
away from speakers.
Bandwidth
The bandwidth capacity is another key point during video transmitting. Regarding the calculation formula of
bandwidth, please refer to the Chapter 6. If upgrade is needed, please consult with your local ISP.
Storage
There are many factors affecting storage requirements. For more information, please refer to Chapter 6.
54
Chap.9 System Design
Decor
Wireless or PoE technologies can greatly help you deal with the decor concerns caused by the tangled cabling.
Additionally, dome type allows cables to be hidden so as to better fit in with the decor of the building.
DI/DO
If you customers need to connect external deices for different application, network cameras with digital input/
output ports are required. Digital input ports connect with sensors such as infrared motion detectors or glass break
sensors while digital output ports connects with alarms.
Operational Requirement Checklist
A checklist will help you plan an IP surveillance that truly addresses your customer’s needs (Table 9.1).
Table 9.1 Pre-installation checklist
Section 1: Purpose
● What is the purpose of surveillance?
 Monitoring  Viewing  Recording  Tracking
 Crime Deterrence / Prevention Of Crime
 Counting
 Detection  Recognizing  Identifying
 Others
Section 2: Floor plan of the monitored site
55
Chap.9 System Design
Section 3: Location
● Where is the camera sited? (camera location)
 Large outdoor places  Small outdoor places  Large indoor places
 Small indoor places  Control rooms  Places with moving objects
 High-contrast environments  Others
● Number of cameras to be installed?
● Types of camera to be installed?
 Fixed  PTZ  Fixed Dome  Speed Dome
● Targets to be observed? (who/what/where)
● Does it monitor any other area not intended? (e.g., private gardens)
 Yes  No
Section 4: Environmental considerations
● Outdoor/Indoor
 Outdoors  Indoors  Vandal-proof housing
 Weather-proof housing  Fan  Heater
● Lighting conditions
 Natural  Artificial  Day/Night  Low light  Challenging light
 Infrared illuminators required  White-light lamps required
 Auto-iris required
● Installation position
 Wall  Ceiling
 Others
 Pole
 Roof
 Corner  3-axis required
● Power and connection
 PoE required
 Wireless required  Power supply  UPS
● Audio
 2-way audio required
● Bandwidth
Mbps
Section 5: Image quality
● Image resolution required
 VGA  1.3M  2M
● Frame rate appropriate to the target’s speed
● Compression techniques for recording
Section 6: Alert functions
● What response is needed for an event or activity?
 Trigger audible alarm  Trigger visual alarm
 Send text message or images  Emergency relay to police
56
Chap.9 System Design
Section 7: Viewing Terminals
 3G phones  PCs
 TVs
Section 8: Recording
● How long will data be reserved?
● How many cameras' images to be recorded simultaneously?
● Any additional information to be recorded with the image?
● Compression techniques for recording?
Section 9: Maintenance
● Equipment should be in good working order, well maintained and serviced
on a regular basis
● Cameras should be protected from any physical/environmental risks
(e.g., vandalism)
57
Chap.9 System Design
9.2 System Planning
Based on the survey above, you can get started with a comprehensive system design plan and select appropriate
cameras, back-end hardware and software for your customers now.
9.2.1 Camera Considerations
Indoor or outdoor application is the first concern when selecting a camera. Other important camera features such
as day and night, resolution (Megapixel or VGA), cabling (PoE or wireless) and compression formats (MJPEG,
MPEG-4 or H.264) or other alternatives will also be main considerations for identifying an exact network camera.
9.2.2 Hardware Considerations
Computer
PC hardware requirements must be higher than 1.7GHz processor and 256MB memory. Free-bundled software
has to be run on Microsoft Windows 2000/XP/Vista.
PoE Switch/Wireless Access Point
PoE switches must be deployed if you are installing PoE-enabled cameras. For wireless connection, you need to
prepare a wireless access point.
NVR
You can have an NVR as a dedicated storage device so as to prevent surveillance video data from sharing the
storage space of PCs.
9.2.3 Software Considerations
Internet Browser
Internet Explorer 6.0 or above and Mozilla Firefox must be installed so as to view video images on PCs. For cellular
phone, 3GPP player is required.
Central Management Software
For a video surveillance system, viewing, recording, playing back, and managing videos are basic functionalities.
VIVOTEK offers reliable free-bundled 32-CH ST7501 central management software to meet your various
requirements.
Other Software
Besides central management software, many customers expect to have more advanced functions such as
intelligent analytics for a variety of applications. VIVOTEK has been working closely with numbers of well-known
software partners as our SIA (Software Integration Alliance). For any specific need, you may check out our website
at http://www.vivotek.com/alliance/siaprogram.html for further information.
9.3 Installation and Check
9.3.1 On-site Installation
Based on the abovementioned plan, you can start to install the surveillance system.
9.3.2 Post-installation Checks
One the installation is over, it is necessary to perform post-installation checks. Below is a checklist that helps you
ensure a successful installation.
58
Chap.9 System Design
Table 9.2 Post-installation checklist
Section 1: Image quality
 Can each camera provide coverage as planned?
 Can images be rendered clearly?
 Can each camera provide sufficient frame rate?
Section 2: Alert functions
 Can alarm sensors be triggered as expected?
 Can security staff and administrators be alerted immediately?
Section 3: Viewing Terminals
 Can video be displayed appropriately on viewing terminals?
Section 4: Recording
 Can recorded data be located correctly?
 Can images be well preserved before being overwritten?
Section 5: Export/Archiving
 Can export and archiving functions work normally?
9.4 Operational Training
Security staff, system operators and managers must be trained to know how to operate the system and what they
should do when an incident occurs.
Table 9.3 lists necessary training items for security staff/operators and managers.
Table 9.3 Operational training requirements
Security guards/operators
Hardware
Software
Administrators
Configuration
Configuration
Remote monitoring
Troubleshooting
Troubleshooting
Remote playback
Authorization
Authorization
Passwords
Remote monitoring
Remote monitoring
Image search
Image quality configuration
Image quality configuration
Functional configuration
Functional configuration
Back-up
Response to alarms
Recording configuration
59
Chap.9 System Design
9.5 System Maintenance
Regular maintenance is required in order to ensure optimal performance and longer lifespan for the system.
Short-term maintenance must be performed regularly, for example, twice a year. For long-term maintenance, it is
important to select a vendor that provides a long-term warranty so as to ensure every component is available when
replacement is needed. VIVOTEK provides a warranty of one to three years, depending on different products. With
130 distributors worldwide, VIVOTEK can provide comprehensive maintenance services.
During maintenance, all equipment must be inspected thoroughly. Make sure all components as well as
connections and cabling are in good conditions without rustiness, erosion or damage. It is also important to confirm
with the clients or examine the system during maintenance to see if the system needs expansion.
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Chap.10 Intelligent Video Systems
Chap.10
Intelligent Video Systems
10.1 Introduction
The need to retrieve useful data in a more efficient way and to provide more prompt response has contributed to
the development of intelligent video systems. The architecture of an intelligent video system mainly includes the
centralized and distributed types.
10.2 Architecture
10.2.1 Centralized Platform
A centralized intelligent video system performs video content analysis at the back-end. It uses an intelligent DVR
featuring high computing capabilities to analyze and process data from all cameras.
Intelligent DVR
Switch
PC
Video Analysis
Analog Cameras
Analog-to-digital Convertion
Video/Audio Compression
Video/Audio Management
Video/Audio Storage
Figure 10.1 Video content analysis in centralized architecture
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Chap.10 Intelligent Video Systems
10.2.2 Distributed Platform
A distributed intelligent video system uses intelligent network cameras to analyze video content in real time so as to
enable prompt response. The architecture can be easily expanded by adding new cameras.
Internet
Switch
PC
Video/Audio Management
Video/Audio Storage
Intelligent Network Cameras
Video Analysis
Video/Audio Compression
Figure 10.2 Video content analysis in distributed structure
Compared with centralized architecture, a distributed intelligent video system provides benefits in deployment
costs, bandwidth requirements and content accuracy (Table 10.1).
Table 10.1 Comparison of centralized and distributed intelligent video systems
Platform
Centralized
Distributed
Features
 High CPU
 High performance with
 Lower recording
 Higher accuracy from
requirements
search efficiency
minimum investment
pre-compression image
processing
 Higher bandwidth efficiency
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Chap.10 Intelligent Video Systems
10.3 Advantages of Distributed Architecture
Since a distributed intelligent video system has video content analyzed by the front-end cameras, it offers the
following benefits.
Real-time Analysis and Response
Because captured images are analyzed in real time at the camera side, unusual activities can be detected
immediately. This allows for prompt response such as notifying security staff.
Reduced Labor Costs
An intelligent video system can constantly concentrated on analyzing and processing data, significantly reducing
the number of security staff and the travel costs resulting from on-site maintenance.
Decrease in Server Workload, Storage Space and Bandwidth Usage
Because only event relevant and needed information is transmitted to the back-end system, server workload is
significantly reduced. It also cuts down bandwidth usage and storage requirements.
Scalability and Integration
Intelligent video systems can be integrated with other systems to serve purposes beyond security, such as in
combination with access control system for more efficient entrance management or with retail POS systems to
provide customer information. Further, during expansion, users can simply add new intelligent cameras at the front
end without needing to upgrade the back-end system for stronger processing capability.
10.4 Detection
10.4.1 Tamper Detection
Tamper detection can detect and respond when the camera is redirected, defocused, blocked or spray-printed. It
allows cameras to be installed in tampering-prone places such as transportation stations or prisons.
Blockage
Redirecting
Defocusing
Spray-painting
Figure 10.3 Tamper detection
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Chap.10 Intelligent Video Systems
Alarm
Figure 10.4 Alarm triggered by tamper detection
10.4.2 Intelligent Motion Detection
Intelligent motion detection can distinguish moving objects of interest motions from natural movements and trigger
alarms based simply on object motions. The function, mainly for outdoor applications, can eliminate false alarm
rates due to environmental noise that appears with conventional motion detection.
Conventional Motion Detection
Conventional Motion Detection
Intelligent Motion Detection
Intelligent Motion Detection
Figure 10.5 Comparison of conventional and intelligent motion detection
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Chap.10 Intelligent Video Systems
10.4.3 Loitering Detection
Loitering detection can detect an object or a person that has been staying in a predefined area over a period of
time. The function effectively prevents crimes because suspicious objects or activities are detected before damage
is caused.
0:01
Presence of Lingering Object
0:30
Alarm Triggered after 30 Seconds
Alarm
00:05
Figure 10.6 Alarm triggered by loitering detection
10.4.4 License Plate Recognition
License plate recognition can identify the plate number of a vehicle and match the information with the data in the
police database. Besides tracking down criminals, license plate analysis can also be used for traffic control and
parking lot management.
9888-GG
Figure 10.7 License plate recognition
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Chap.10 Intelligent Video Systems
10.4.5 People Counting
People counting can calculate the amount of people in an area and provide the information for business
management, such as the number of customers entering the shop or the number of customers waiting in a line.
Figure 10.8 People counting
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Glossary
Glossary
A
AE
Auto Exposure, a system for automatically setting the proper exposure
according to the existing light conditions. There are three types of AE
systems: programmed, aperture-priority, shutter-priority
AES
Automatic Electronic Shutter, the sensor will automatically adjust the
sensitivity according to the changes in illumination of detected area.
AF
Auto Focus, an ability by which the camera lens automatically adjusts
its focus on the captured subject.
AGC
Automatic Gain Control, an electronic circuit which amplifies the video
signal when the signal strength falls below a given value due to the
lack the light on the image device.
Auto-iris
A special type of iris, is used to adjust the amount of enter light,
electrically controlled by the camera. There are two main types of autoiris: Video-drive and DC-drive iris. See also Video-drive Iris and DCdrive Iris.
AWB
Automatic White Balance, is used in digital camera to automatically
compensate the type of light (daylight, fluorescent, incandescent, etc.,)
or lighting conditions in the scene. To make it normal for the human
eye.
B
Bit Rate
A unit of speed, defines the number of bits/time unit, usually expressed
in Kbit/s or Mbit/s.
C
CE
Consultants Europe, is a Technical and Legal organization specialized
in the CE marking, CE certification and Authorized Representation of
products.
Codec
Codec stands for Coder/ Decoder, which converts analog video and
audio signals into a digital format for transmission. The codec also
converts received digital signals back into analog format.
Contrast
Contrast is usually defined as a ration between the darkest and the
brightest posts of an image in image processing Images have a higher
contrast level generally display a greater degree of color grayscale
variation than those of lower contrast.
D
DC-drive Iris
One type of auto-iris, will automatically adjust the amount of light
allowed to enter. It requires simply a DC input from the camera without
signal converted.
Digital Zoom
Digital zoom takes part of the image and expends it. The resulting
image appears bigger but not as sharp as with an optical zoom.
Frame Rate
The rate at which video frames are displayed on a monitor per second.
Frame rate for PAL is 25 fps, and frame rate for NTSC is 30 fps.
H
Hue
It is an attribute of color and the other two elements are brightness
and saturation. Hue differences depend primarily on the variations of
wavelength and defined by its dominant wavelength.
I
IGMP
Internet Group Management Protocol, is a protocol that manages PCs’
multicast group membership. It provides the membership information
of a PC to a multicast router, which sends out queries periodically to
confirm the status of that PC. A PC can request to join in a specific
group, and when it becomes a member of that group, it will receive
data designated to that group.
M
MAC Address
Media Access Control address, is one unique code assigned to a
networking device. For example, the network card in a computer has
its own MAC address.
O
Optical Zoom
Optical zoom amplify the image size by adjusting the lens. It enlarges
the subject without sacrificing resolution.
P
Proxy Server
A server that provides the service for clients to make indirect network
connections to other network services.
Proxy server will save the previous data or resource in a cache when
the request is made for first. To provide it when the same request is
made again. It could be used to avoid occupying much bandwidth.
R
RS-485
RS-485 is an electrical specification of a two-wire, half-duplex,
multipoint serial connection. It supports high data transmission speeds
and uses a different balanced line over twisted pair. It also spans large
distances.
RTCP
Real-Time Control Protocol, is used to monitor the session. It is mainly
used to feed the streaming server with reception statistics from the
client. The server may then decide to use these statistics (such as the
numbers of lost packets, the delay from reception) to adapt its strategy.
RTP
Real-Time Transport Protocol, is the protocol used to transport the
multimedia stream to the client. It sends a packet to the network but
cannot warrant that the packet will reach its destination.
D-SUB
S
F
Saturation
D-SUB is used to indicate the type of connector for the VGA interface.
FCC
A measurement of chrominance, or the intensity of color in the video
signal.
Federal Communications Commission, is responsible for a
administering the television and radio airwaves, satellite and cable
transmissions, and telegraph communications.
V
Fixed Iris
One type of auto-iris, a Video-drive iris lens has an amplified circuit for
converting input video signal to a DC input for the camera.
Fixed iris lens is one kind of iris and with fixed size iris.
Video-drive Iris
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Notes
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