Communication Mediums for Signal, ITS, and Freeway Surveillance Systems Final Report (1996) / Chapter Skim
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A.1.6 Video Applications in ITS
A.1.6 Video Applications in ITS
Pages 246-262
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From page 246... ...
Table A.~.6~1 Application of CCTV Cameras in ITS Conventional Advanced with Modern Signal _ _~ · Traffic surveillance supporting · Automated collection of occupancy, congestion analysis volume, speed and vehicle classification (Autoscope_ -like) · Incident validation, seriousness information assessment and clearance verification · Enforcement, vehicle management, · Road hazard evaluation (debris on road, and fee collection through flooding, large pot holes, etc.)
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From page 247... ...
If the integration goals of llS are to be achieved, video and supporting communication infrastructure should be implemented wad equipment in compliance USA open standards and capable of multivendor interoperability. Jurisdictions implementing ITS systems in He mid 1990s, with significant CCTV video surveillance, goals face difficult technical implementation decisions due to rapidly emerging digital video technologies, components, equipment, and standards.
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From page 249... ...
. A transmission encoder converts these dlree components to a single composite video signal by modulating He chrominance (color information)
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From page 250... ...
There is much debate within He television industry as to whether the evolution should be to ~TV or to a digital transmission standard that is closer to He current analog NTSC standard in picture quality. t;\NCHRP`Phasez.rp~\ NCHRP3-51 · Phase2FtnalReport Al-242
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From page 251... ...
Charged Coupled Device (CCD) technology emerged in 1969 and became the facilitator for lower-cost, small, color CCTV cameras of He 1980s.
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From page 252... ...
. CCD technology revolutionized CCTV cameras, facilitating employment of chromic capability in a small, compact, electronic unit.
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From page 253... ...
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From page 254... ...
· Other functions, such as ins control, automatic focus, etc. The above functions have traditionally been accomplished in cameras by analog circuits; however, DSP technology has become cost competitive with comparable analog technologies and offers enhanced performance for the replaced analog functions plus He ability to implement feature enhancements such as electronic image stabilization and electronic zoom.
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From page 255... ...
The DSP camera has significant potential to achieve a superior image quality compared with conventional CCTV cameras.
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From page 256... ...
It seems clear Hat future costeffective video options for ITS-related applications will include systems and equipment based on these emerging requirements and related standards. Most video compression algorithms results In some sacrifice in picture quality or modon.
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From page 257... ...
Developed to provide CIF resolution of 352 by 240 (VHS quality) at transmission rates of 0.7 Mbps to 6 Mbps (primary design goal was to deliver compact disc video at 1.416 Mbps)
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From page 258... ...
developed a video standard oriented toward optimum inhaframe compression, to transmit a single video image over telephone lines achieving high image quality with low communications bandwidth. The JPEG standard was not designed for motion but rather for still frame communications.
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From page 259... ...
has developed a compression algorithm called MARC-C which reportedly can compress a frame up to 300: I, providing an image of better quality than He lower compression redo of JPEG. Based on field test results of video compression aIgonthms for ITS freeway applications, a minimum acceptable data rate seems to be 3.08 Mbps, assuming that a usable quality image is desired to justify expenditure of a deployed CCTV camera win pan/~It/zoom (P=.
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From page 260... ...
It is very important that the llS designer properly select codec to: Meet high motion requirements of traffic, Be compliant win communications bandwidth availability, Meet video signal distribution and reception requirements Support priority CCTV camera control within distributed system architecture, and Provide a quality video image display justifying investment in CCTV camera deployment cost. Some misconceptions indicate Mat use of digital video is non-cost-effective in systems, and thus Cat overlay analog video distribution networks should be considered.
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From page 261... ...
A modem network, such as SONET, has very him availability and, win video codec, can support multimedia communications at lower life cycle costs. A.~.6.4 ITS Video Communication Issues Figure A.~.6.4-1 provides a simplified block diagram of a typical ITS video surveillance network.
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From page 262... ...
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