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© Robert Bosch GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such as copying and passing on to third parties. U1 - 1 CCTV Digital Basics CCTV Digital Basics
CCTV SYSTEMS Digital Basics
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CCTV SYSTEMS
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10.16.03 / Internal
© Robert Bosch GmbH reserves all rights even in the event of
industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties.
Unit 1 – Defining Digital
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industrial property rights. We reserve all rights of disposal such
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CCTV Digital Basics
10.16.03 / Internal
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industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties.
Objectives
Department
Describe the components of digital imagery
Describe two factors that can impact pixel resolution
Define a “bit” and how it is used in digital video
Define a “byte” and how it is used in digital video
Identify the differences between digital and analog signals.
Describe at least three advantages of digital vs. analog related to
CCTV
Unit 1 – Defining Digital
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Advantages of a digital network system
Scalability – Easily scaled from one to thousands of camera in any
increment is possible. Can do any frame rate from any camera at any
time.
Cost efficient infrastructure – Ability to use existing wired
networks or wireless transmission. Opens new areas of access and
cost savings for installation.
Remote access & control – Any video source can be accessed and
controlled remotely from anywhere in the world over wire/wireless
networks. Intelligence of the camera functions can be established
at the camera location (motion detection, event handling, output
type, time/date, etc.).
Lower cost – An IP CCTV system can easily leverage from existing
network systems, business support resources, and storage
capabilities.
Unit 1 – Defining Digital
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Unit 1 – Defining Digital
Digital Hybrid CCTV Systems
Advantages Clear, precise and discrete signal values, which allows
for customized image quality options Ability to manipulate and
compress the signal data for duplication, transmission and storage
flexibility The ability to send signals through non-dedicated
transmission media Flexibility in the storage, file transfer,
copying and archiving Simultaneous record and playback Fast and
detailed search capabilities Non-degradation of recorded video with
use/playback Digital recording can incorporate encryption Low
maintenance on digital record components
Disadvantages Video signal conversion required:
analog-digital-analog Digital components typically more expensive
than analog System still requires some dedicated transmission path
Transmission distance limitations Video storage limited by hard
drive space System expansion my be limited by dependent components
(i.e. need to buy more switchers) More users on system may slow IPS
speed. May not be real time video
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industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties.
Unit 1 – Defining Digital
Analog vs. Digital
Analog CCTV Systems
Advantages Uses traditional video cameras, transmission methods,
and VCR recording Relatively inexpensive to build a system Simple
and familiar to use Modular configuration to add/replace components
Provides real time, full video resolution
Disadvantages Requires dedicated transmission path Transmission
distance limitations Time consuming video searches System expansion
my be limited by dependent components Video tape and recordings
wear out/degrade with use Higher maintenance of VCR Bulky storage
requirements of tapes Inflexibility in use of recorded video
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Unit 1 – Defining Digital
100% Digital CCTV Systems
Advantages Digital signal throughout system, and all the benefits
of a digital signal No dedicated cabling required, uses existing
computer networks Easily scalable system Non-centralized control
centers “Virtual hard disk” possible System redundancy network
provides
Disadvantages Network congestion and bandwidth limitations Expense
of components (may be offset by savings in cabling) Same security
concerns as any computer network system Competing proprietary
standards
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industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties.
What is Digital?
ON or OFF states
Binary Code is digital values of either 1 or 0
Bit – smallest form of digital information – a single place value
made up of a 1 or 0 (on or off)
ANALOG
Ability to produce great amount of detail (wanted or
unwanted)
Susceptible to unwanted variations
Unit 1 – Defining Digital
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Analog vs. Digital Wave
Unit 1 – Defining Digital
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Analog to Digital Conversion
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Pixel Information
1
5
8
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Bit Depth
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Digital Primary Colors
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Bits
BITS – Smallest form of digital data, represented by 1 or 0 values
(ON or OFF)
Data transmission is usually in Bits = bits per second (bps)
Modems: 28.8 Kbps, 33.6 Kbps, 56 Kbps
LAN networks: 10 Mbits/sec., 100 Mbits/sec., 1 Gbits/sec.
Unit 1 – Defining Digital
1 (off)
1 (off)
0 (on)
0 (on)
0 (on)
Bit values
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Bytes
Unit 1 – Defining Digital
BYTES – A grouping of bits to make a total value that could
represent a number, word, calculation or a color
Transmitting Bytes = Bytes per second (Bps)
File sizes & storage media expressed in Bytes
Files: 15 KB, 12 MB
Hard drive: 40 GB.
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File sizes
Unit 1 – Defining Digital
For each video frame captured, a video file is created. That file
size is dependent upon the following:
Total number of pixels on CCD based upon its dimension (ie. 768 x
492 = 377856 pixels)
Pixel Bit Depth as determined by the Digital Signal Processor (i.e.
8 bit)
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File sizes & video
Unit 1 – Defining Digital
Images per Second (ips)
Video captures a certain number of individual files or images every
second
This rate of image capture has a big impact on the data volume to
be transmitted and stored.
2 ips
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Answer the review questions
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Unit 1 – Defining Digital