Prerelease AYWTK CCTV

8/9/2019 Prerelease AYWTK CCTV

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All you wanted to knowabout…

Closed Circuit Television(CCTV)…

But didn’t know what to ask.

By: Paul Broo e !broo e"co !aircctv.co www.co !aircctv.co #ate: $%&'%'

1

mailto:[email protected]:[email protected]


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Table o Contents:

*orward:.............................................................................................................................&+ntroduction:......................................................................................................................,Basic Video -yste Co !onents A history lesson:...................................................... /0ld CCTV !arts that 1ust won’t 2o away:....................................................................../

Ti e la!se VC3:............................................................................................................/4anual switch:.............................................................................................................../-e5uential -witcher:......................................................................................................6Video -!litter:................................................................................................................6Picture in a !icture:.......................................................................................................64otion detectors:...........................................................................................................67uads:.............................................................................................................................64ulti!le8ers:..................................................................................................................Virtual 3eal ti e VC3:................................................................................................All in one V9- recorders:.............................................................................................

0ther video accessories o note:.......................................................................................Video ;ine a !li iers:...................................................................................................#istribution a !li iers:.................................................................................................Coa8 cable:.....................................................................................................................Video Baluns...................................................................................................................<Power -u!!lies:..............................................................................................................<=P- !ower su!!lies:......................................................................................................<>V4 -witches:............................................................................................................$'4onitors:......................................................................................................................$'Ty!ical onitor dis!lays:............................................................................................$$

Ca eras:.......................................................................................................................$?4atri8 -witches:..........................................................................................................$,#V3 (#i2ital Video 3ecorders):.................................................................................$/@V3 (@etwork Video 3ecorder):...............................................................................$6

+s the latest and 2reatest always the best .....................................................................$@otable Transitions in CCTV:........................................................................................$

hy bother usin2 alar s to increase record rates. hy not record all ca eras asast a !ossible all the ti e .............................................................................................?'

Addendu $: VC3$'$ and VC3$'?...........................................................................?$Addendu ?: Pi8elsD record s!eed and C+*:..............................................................?Addendu &: EPicture 7ualityF...................................................................................&?

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*orward:

Are you really going to learn all you wanted to know about CCTV by reading this paper?It seems unlikely that such a relatively short document could contain all that muchdetailed information !n the other hand" you may #ust be looking for a brief overview ofthe history of a topic that could bring you to tears when hearing the long version Thevalue in this brief description of old product solutions is that most of these samefunctions are included with the latest $V%s &hining the spotlight of truth on these itemsone at a time may give you some insight into why people still want" or need thesefunctions in the digital age If all you are looking for are basic facts" general informationand a few anecdotes" this may be #ust the kind of reference material you're looking for

A wise person once told me that if I wanted to (uickly learn something about a sub#ect Ishould go to the children's section of a library and see what books they had to offer Thesub#ect is described in simple terms" leaving out much of the e)cruciating detail" and

provided in a straight forward way that even a child can understand About *+, of whatyou would get from a detailed te)t is in the children's version !nce you have workedyour way through the book you may find that you have discovered all you wanted toknow about the sub#ect This cursory review may give you the information you need tosound knowledgeable and better able to understand the in-depth versions provided byothers

That thought is behind the title of a series of papers that I've written on several productspecific and other loosely related sub#ects This document" .All you wanted to knowabout/ CCTV0 provides a brief description of many hardware devices used in CCTV"some background information where it is useful and an occasionally humorous slant onan otherwise dry technical sub#ect

&o kids" if you find yourself trapped on a plane" or the passenger in a car on your way to acustomer facing e)perience where your CCTV knowledge may be tested" this could be

#ust the thing to pass the time

If you want #ust a little more detail on some of the items mentioned" I have written paperson some of the individual sub#ects Check the documents page on www compaircctv com

http://www.compaircctv.com./http://www.compaircctv.com./


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+ntroduction:

CCTV Closed Circuit Television3 is a continually changing sub#ect 4ew technologiesspring up to replace the old at a deafening rate As soon as you hear about the newestsolution" another product is beating the drum for attention 5ou might think that the oldtechnology would recogni6e that it has been outdone and fade away !f course some hasThe rest hangs on" still providing service as well as it always has in the past These oncee)pensive solutions to individual applications are now only a fraction of their original

price The original manufacturers may have long since abandoned the products due todeclining prices and newer replacements 4ew manufacturers have duplicated thefunctionality if not the original design3 and are willing to proceed with limited margins

Customers who were priced out of the original offerings are now seeing the benefit of thetechnology at today's price points" e)panding the low end market for CCTV productsThe traditional higher end customers still have a working inventory of the old productsand like to purchase newer products that are compatible with their current investmentCustomer demand has re(uired newer products to incorporate much of the functionalityof the older products into the newer designs 7eople often ask why this is true This paperattempts to answer this (uestion and some others that you may not know to ask

$V% $igital Video %ecorder3 products provided by .old guard0 CCTV manufacturerstypically provide most of the video features that e)isting customers are familiar with 8ora while" it looked like new manufacturers from Asia were going to pass the old guard bywith lower priced 7C based $V% products touting bigger numbers for refresh rates andrecord speeds Although better in many respects" they lacked an established channel tomarket the main reason3 and they were not tuned in to the customer re(uirements fortraditional CCTV capabilities 9hile they were figuring this out" the old guardmanufacturers came up to speed and added additional features &ome traditional :&manufacturers went the !;< route" partnering with Asian manufacturers

This document is intended to provide a history lesson of information on past and present products If you are new to CCTV" or unaware of what products are out there" this is agood starting point to make you aware of what you don't know so you can do furtherinvestigation where necessary

$on't feel bad if you aren't familiar with the basic components used in CCTV


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Basic Video -yste Co !onents A history lesson:

The products listed have been around for a while Although you may be selling the mostup to date products" most of the functionality of these early product entries is included inthe latest $V% products These features may be overlooked and unused by many" butthey would be sorely missed by .e)perienced0 users

The very basic video system consists of a camera" a cable and a monitor The cameracaptures images" the cable transmits the images to the place where you want to see themand the monitor provides the visual display of the images There are of course" manyverities of cameras" many different connection methods and a growing array of monitorsavailable In the beginning/

0ld CCTV !arts that 1ust won’t 2o away:

A CCTV system consists of a camera" a cable and a monitor 9ould you like to add asecond camera to your video system? ust get another camera" another cable and anothermonitor

It doesn't take long to reali6e that you are going to need a lot of monitors as your systemgrows If you want to record the video on a VC%" you'll also need a VC% for everycamera The need is to create a way to view and record more than one camera on onemonitor and VC%

Advantages@ 8ull si6e" real-time image display on each monitor$isadvantages@ 5ou need lots of e(uipment as systems grow si6eBspace re(uirements

Ti e la!se VC3: Time- apse VC%s used in security are based on the standard homeVC% These modified versions record for different lengths of time according to the modeselected Two-hour mode is like a standard VC% 2>-hour mode typically records fiveimages per second rather than the D+ available from the camera3 This is fine for a singlecamera but may cause issues when used with a multiple)er that also time divides theimages

Advantages@ 5ou can record for e)tended periods of time on a single VE& tape up to FD+hours3$isadvantages@ The longer the record mode" the more time between each recorded imageand more information is missed

4anual switch: 4ot to be overlooked" a basic manual switch is a valuable tool in this basic application and for selected uses in the most comple) solutions

Advantages@ &imple easy solution that anyone can install$isadvantages@ &omeone must manually press the button when re(uired

G


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-e5uential -witcher: 4ot to be confused with a


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Advantages@ View and record four images on one monitor and VC%$isadvantages@ ;ach image is smaller oomed playback images have low (uality

4ulti!le8ers: Video multiple)ers have been around in their current form since 1FFThis was a first digital step into time divided video as a trade off for accommodating

more video channels with less e(uipment hour virtual real-real time recorders hit the market soon after the multiple)ergained in popularity The original multiple)ers had a 2+ image per second ma)imumswitch rate slow by today's standards3 Time-lapse VC%s recorded Gips in 2>-hourmode 9ith everything timed perfectly" you get a recorded image of each camera every

2 seconds Although there are a lot of alarm tricks you can do to increase the recordingof alarmed cameras" this is done at the e)pense of the other cameras Jesides that" most

people don't use them or can't figure out how3 The 2> hour virtual real-time recorderwas designed to ma)imi6e recording with a multiple)er It recorded at 2+ips capturing allthe available images from the multiple)er and bringing the time between updates of eachcamera to * seconds This product combination is very popular with retail and other

businesses where there is someone there to changes tapes seven days a week

All in one V9- recorders: 5ou can still buy the individual types of VC%s used inCCTV This is an e)tremely price driven product The most popular models now have allthe different modes in a single bo) including standard time-lapse and high density timelapse modes ;)plaining all the VC% modes is comple) so either see the addendum for acopy of VC% 1+1" or stick to selling all digital products

0ther video accessories o note: There are catalogues filled with parts usedin CCTV installations


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feature that a customer #ust has to have I mention a few products here because they areoften essential to camera installations All the items mentioned here and previously arestill important to you even if you are concentrating on selling new digital products Thefunctionality of most of the individual products mentioned is also included in the moresophisticated devices &o you can't really get away from them

Video ;ine a !li iers: There is a limit to how far you can transmit a video signalthrough coa) cable usually *++ feet using %LGF cable3 A line amplifier boosts thesignal amplitude to allow as much as G"+++ feet of cable to be used

Advantage@ It can rescue you from that one camera that ended up further from the controlroom than you e)pected$isadvantages@ Additional cost that my not have been anticipated

#istribution a !li iers: If you need to send the same camera video to more than one place" your options are to loop the video through one device to the ne)t removing the

termination from the first device3 or using a distribution amp A single camera input isisolated and distributed to several outputs $BAs come in a variety of si6es one inBfourout" four inB1D out" 1D inB1Dout" etc3 $espite the name distribution .amplifier0 it is rareto find one that actually amplifies $on't e)pect it to e)tend the distance rules for cablelength A distribution system is a necessity in large installations where the same camerasare viewed from multiple locations

Advantages@


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CATG3 This is a growing trend CATG cable can be easier to work with than coa) and itis less e)pensive The baluns come in passive and active versions depending on the wirelengths re(uired The manufacturers (uote distances based on a camera at one end and amonitor on the other $V%s don't seem to be as forgiving as monitors and the usabledistances are considerably shorter Color gives up first Active baluns have gain

ad#ustments to optimi6e the video presentation ;)pect one third the (uoted distanceThe products range from single baluns you need one at each end3 to multi-channel rackmounted devices !ne very large installation has hundreds of video feeds using cabinetsof rack mount devices using CATG bundles of 2D twisted pairsVAC" >" *" 12" 1D" 2 outputs" etc3 $o make sure you have sufficient current rating to

power the desired e(uipment and use the proper gauge wire for the distance involved

Advantages@ Clean professional looking installation Central access for maintenance$isadvantages@ Cost" space and long wire runs

=P- !ower su!!lies: :7& :ninterruptible 7ower &upplies"3 isolate e(uipment from theincoming power line They were originally very e)pensive


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Advantages@ 7ower .insurance0 to protect against power glitches and failures$isadvantages@ Additional cost and space re(uirement

>V4 -witches: MV< stands for Meyboard" Video and and * input desk top models to large rack mount models with 1D inputs5ou can daisy chain four or more3 units together to accommodate very large systems Iknow of at least one user with over one hundred $V%s connected to a single operatorsystem

Advantages@ MV< switch can save on lots of monitors and the space needed to housethem !ne operator can control all systems from one control station $V% normal

operation is typically done from the remote software in these applications$isadvantages@ 4ot user friendly when several operators want access the e(uipment roomfor maintenance There are lots of cables to contend with

4onitors:


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the product provider to have done the testing" or build your own e)perience byviewing the products yourself It is always a good idea to test a sample beforeinstalling hundreds of them

- C$" T8T and pro#ection monitors typically run at a variety of screen formats*++)D++" 1+2>)KD*" etc 3 This does not necessarily mean that they will look

good at all the available settings


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C$ i(uidCrystal $iode3

VLA" composite 1G0 to K0 Computer displayandBor composite

T8T Thin 8ilmTransistor - a higher (uality and si6e

version of C$3

VLA" composite :p to G+0 Computer displayand composite!ften used to

display multicomputer windows7lasma 7$73 VLA" composite K to D10 Computer display

and composite!ften used todisplay multicomputer windows

7ro#ection system VLA" composite Variable" dependingon si6e ad#ustmentand distance fromthe wallBdisplay

screen 12' by F' isusually obtainable

Computer and video presentations argevideo displays oftenincorporating multi

windows and orcameras

Ca eras: The image (uality produced by a security system will never be better than theoriginal image captured by the camera A good camera does not guarantee a good finalresult A bad camera will limit what can be done with the image passed on the othercomponents in the system

Tube ca eras: Tube cameras are thankfully gone from the CCTV landscape There are afew people hanging on to tube cameras in old installations" but they are a rare find

CC# ca eras: CC$ Charged Coupled $evice3 cameras are still the predominantcamera type in CCTV They are very reliable


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Vari-focal lenses change the field of view presented A typical vari-focal lens can ad#ustfrom Dmm to 12mm and some can be found at a reasonable price at G-G+mm &omeinstallers still use charts to try to figure out the precise lens si6e re(uired for all camerasin an installation


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+3 ca eras: I% cameras are in a different high price3 category These cameras seeoutside the visible human spectrum and provide a black and white image that highlightsob#ects with higher heat content than their surroundings These are true see in the darkcapable cameras A normal camera won't show you someone hiding in the bushes but an

I% camera will

#ay%@i2ht ca eras: $ay night cameras typically switch from color in the day light toJB9 when the light diminishes This provides better night images in black and white

provided some level of lighting is available

+P Ca eras: I7 Internet 7rotocol3 cameras are the growing trend ;ach camera is avideo server ust connect an ;thernet cable and power and you're in business 5ou don'teven need the power connection if you're using 7!; 7ower !ver ;thernet3 Jrowser

based remote software will allow configuration and viewing of the camera video I7camera manufacturers and $V% 4V%3 manufacturers are partnering to allow

compatibility between products

Pro2ressive -can Ca eras: 7rogressive scan cameras are still a mystery in traditionalCCTV applications


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Eis $V% cousin is a little more laid back" knowing that all the action is being recordedwhile he attends to other tasks The fact that the $V% isn't recording fluid motion on allcameras is of little conse(uence as he knows that only a few well timed images areimportant for suspect identification This may be attributed to the $V% guy's casual

attention to TV and avid connection with computer video downloads

If you wanted to record all the cameras in the early days your only option was the VC%A peek into a casino back room might reveal hundreds of standard VC%s recording eachcamera individually $on't stand in the doorway at tape changing time as a crew of fastmoving individuals will be rushing through to change the tapes in all the machines Thisscenario still takes place at many casinos today every si) or eight hours3


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and the ability to connect to the $V% remotely via ;thernet highlighted the leap in value provided by digital and networked devices

arger disk drive si6es increased storage capacity while record speeds of $V%scontinued to rise The initial +ips units recorded continuously for about two hours on a

two gig drive Today's >*+ips units will record continuously for about 2 hours on asingle G++LJ drive


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+s the latest and 2reatest always the best

The natural tendency is to think that new development in technology is a continuouschain of improvements This is not necessarily true 9hen you successfully apply a newapproach to solving an old problem you often find that by the time the product is readyfor release the basic premise of improvement is achieved and something dramatic isimproved 5ou may also find that the original products had some convenient and widelyused features that were either forgotten or unable to be addressed in the new design &alesob#ections will immediately concentrate on these issues After a period of time" the.needed0 additional features will find their way into the newer products" or fade to thefolklore of times past

Cases in point@ Tube cameras had really good video (uality compared to the initial CC$cameras3 and really short operating lives &o the big ob#ection to the initial CC$ cameraswas .low (uality images 0 &ince tube cameras were pretty much unusable after a year ortwo in operation and many of the original CC$ cameras are still in use twenty years later"the ob#ections soon faded Incremental improvements in CC$ cameras made them whatthey are today 4obody is saying .Lee" I wish I could find some of those old tubecameras to install in a big casino deal 0

;ach new device is a trade off They have advantages and disadvantages


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complicated archiving to tape Jig drives and small tapes made for a labor intensive backup process ;ventually drive capacity reached the si6e where most users could retaindata longer than they needed it Archiving to $AT pretty much disappeared in videoapplications %AI$ systems are often used in the most critical applications to address safestorage needs

7robably the single biggest eye opener for $V%s is the Internet Jased on 7C andnetwork technology" remote software allowed operators to view live and recorded videofrom anywhere Take that VC%O3


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product in place and in production thatwill keep 4V%s in the hybrid mode forsome time

I7 cameras replacing CC$cameras

Traditional cameras still have a strongadvantage in video (uality and sales

familiarity A video server in every cameramakes the I7 camera the one to bet on inthe long term

2++G - ?

7rogressive scan camerasovertaking 2@1 interlacecameras

The CCTV industry is built on the 4T&CB7A standards interlaced fields3


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hy bother usin2 alar s to increase record rates. hy notrecord all ca eras as ast a !ossible all the ti e

There are several things to know before understanding the answer to this (uestion

- %ecord speeds were not always as fast as they are with today's units Alarms andother indicators were used to increase the record rate of alarmed or all3 camerasfor the duration of the alarm condition

- 7eople are used to altering record speeds with alarm conditions and typically wantto see these features included for other reasons beyond update speed

- 4ow that record speeds are generally faster with +ips from each cameraachievable3 and with >CI8 recording" people noticed that their drive spacecouldn't retain the duration re(uired for their application

In the beginning" $V% and multiple)er3 record speeds were slow Connect 1D cameras at+ips total and it will take over two seconds to see a new update of each camera 5ou

might even slow this rate down to allow your record duration to match the total recordtime needed for the application &o what you were getting is an occasional update fromeach camera If something important happened on one camera" the demand was toincrease the image update to as close to real-time as possible while the important eventwas occurring Typical solutions included temporarily increasing the record speed of allcameras andBor interleaving the active cameras at a faster se(uence &ome units allowe)clusive recording of the alarmed camera !f course you are not recording the othercameras in this mode

9hichever method employed" the additional updates of one camera come at the e)penseof the others The good news is that you get more updates of the camera you want and

bad news includes fewer recorded images of the other cameras and shorter overall recordduration due to increased storage demand

Alarms are important for many reasons other than increasing the record rate Currentversion $V%s have an impressive array of features tied to alarms in addition to speedchanges 8or instance@ Alarms generate an alarm list for easy review" forward alarmnotification to remote software users" send emails to selected addresses and trigger

positioning of other dome cameras to better watch the action &o alarms are here to stayand users are asking for additional feature to be added to products


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Addendu $: VC3$'$ and VC3$'? are old documents that will providesome insight into the types of VC%s used in security and the applications for each

VC3 $'$:VC% is an acronym for Video C assette 3 ecorder All VC%s are based on the one you have athome


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hat have we learned so ar

1 Cassette tapes come in different lengths" which affect the length of record time2 VC%s can record in different modes" which affect the length of record time and the picture

(uality

Co and ents o understandin2 VC3s:

I All types of VC%s are based on the home VC%II Tradeoffs are made between record duration and image (ualityIII Tradeoffs are made between record duration and image update rateIV There are four general types of VC%s

1 Eome VC%2 Time-lapse VC%

2> hour .real-time0 VC%> Eigh density VC%

Co ercial VC3 (ho e style): This is the VC% you have at home It is designed to play andrecord movies in con#unction with a television It can range in comple)ity from record only withno additional functions to a variety of features including pauseBstill" single step and multiple eventrecording They all have one thing in common" they are to difficult for humans to figure out"unless you are a VC% savant There are typically two" or" three record speeds they are calledspeeds" even though they are actually lengths of time 3 &7 is standard play 2 hour 3 7 is long

play > hour 3 ;7 is e)tended play D hour 3 These times are relavant with T12+ tape T P time"12+ P 12+ minutes 3 The longer record settings use thinner record heads so that more images can

be recorded on the same length of tape Huality suffers as record time increases because thesmaller heads provide less video information

Advantage@ east e)pensive VC% option Always records at a .real-time0 rate

$isadvantage@ imited record time 2hrs - Dhrs with T12+ tape :p to *hrs with T1D+ tapeQ4T&CR 3

9here used@ ;very home Any low end application :sed as an additional recorder in someinstallations &ometimes used to record multiple)er playback from the monitor loop out connector so that a tape can be played back in another location with no multiple)er

Ti e la!se VC3: Time-lapse VC%s typically have several record speeds again" they areactually elapsed times 3 In 2 hour mode" they record and play back #ust like the home VC% &i)hour mode is like ;7 onger time settings are time-lapse" which means that they do not record allthe available images They skip images so that the capacity of the tape can accommodate a longer

period of time 9ant the tape to last longer? ust use a longer time-lapse mode The individual

images are #ust as good" however" they are further apart in time3

Time-lapse VC%s were designed with the security industry in mind ;ven though the price ismuch higher than a standard VC%" the benefits for long term recording make this an economicaldevice for solving problems typically encountered in security &ystem operation re(uires that thetape is changed at a routine interval The attendant can change the tape at the same time everyday" during the normal work week and then switch to a longer time record mode to accommodatethe weekend

22


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Advantage@ A single VC% tape can last for a specified length of time typicallyS 2" D" 12" 2>" >*"K2" 1D*" >*+" FD+ hours3 depending on the VC% selected 7rovides good (uality pictures becausethe &7 head is used for all time settings with the e)ception of the D hour mode" which uses the ;7head

$isadvantage@ 8ewer images are recorded as time-lapse time increases 5ou run the risk ofmissing the detailed action you want

9here used@ Lood fit in any application where a long time span is re(uired The ability to switchfrom 2> hour mode and K2 hour mode" makes this a natural for hours


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$isadvantages@ ower image (uality than traditional time-lapse VC%s due to the use of ;7 head9here used@ Can be used anywhere time-lapse recorders are appropriate Lood trade off between2> hour real-time and time-lapse recorders %ecords for 2> hours at KG, the update rate of real-time recorders and still has longer time lapse modes available for weekends

Co !arin2 ?, hour odes: + a2es !er second: + a2es !er hour: + a2es !er ?, hours:

T12+ T1D+Time- apse VC%@ G 1*"+++ > 2"+++ GKD"+++ 2hr3

Eigh $ensity VC%@ 1G G>"+++ 1"2FD"+++ 1"K2*"+++ 2hr3

2> Eour %eal-Time@ 2+ K2"+++ 1" 1*"G++ 1*hr3 1"K2*"+++ 2>hr3

4ulti ode VC3s: 9ouldn't you know that someone would try to cram all the functionality ofthe four types of VC%s into a single unit? And if you are willing to pay the price" you will haveall these record modes at your finger tips 5ou could record in 2> hour .real-time0 mode hours in a 2> hour .real-time0 recorder3

Eow can a VC% fit the needs of a variety of users? The paragraph above indicates how you cankeep recording over and over on the same tape" however" most applications re(uire archiving ofinformation Typical applications are as follows@1 %ecord everything all the time" with as fast an update rate as possible

2>


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2 %ecord everything all the time As long as I have a few images of each camera each minute"I'm happy%ecord everything" all the time Time-lapse mode is !M for most situationsS however" I needthe fastest possible update rate when certain events happen

> I don't want to wade through unneeded recorded information I #ust want to record whensomething happens

$. 3ecord everythin2 all the ti e with as ast an u!date rate as !ossible: If this is the goaland you are ready and willing to change tapes as often as re(uired" you can use the commercial

home3 VC% in the two hour mode for the highest (uality picture" or" si) hour mode or * hourwith T1D+ tape"3 if the lower (uality picture is acceptable hour .real-time0recorder starts looking very attractive 9ant to record at that .real-time0 rate over the weekend?5ou could use three recorders" using the tape end output of one to trigger recording on the ne)t

?. 3ecord everythin2 all the ti e%slow u!date rate is 0>:


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this" the tape must be moved to prevent damage Although the movement takes place at infre(uentincrements" there are still unwanted images on the tape Time-lapse recorders with an eventrecord mode like the %V2>FD3 will record a field each minute or so The %V2>FD records twofields each minute in +1 mode" two in three minutes in + mode 3 In the +1 mode" with noalarms present" the tape will fill up in 1G+ days A T VC% in FD+ hour mode will fill the tape in>+ days The defacto event record mode is to set the T VC% to its longest record mode andtrigger to two hour mode on alarm This allows alarm recording without recording much ofanything under normal circumstances

Application@ 5ou can get a tape of only alarm images using a multiple)er 4ever discourageanyone from recording all images all the time from the designated VC% record output of themultiple)er :sing a second VC%" you can record from the loop out of the call monitor The VC% sits idle until triggered by the multiple)er alarm output The alarmed camera switches to the callmonitor Viola" the VC% records the alarmed camera 5ou can set the record duration in themultiple)er menu


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Addendu ?: Pi8elsD record s!eed and C+*: This document" 7i)els"%ecord &peeds and CI8" provides some interesting input on the dark side of some recentfeatures Je careful with how you use this information Although it is factually true atleast until a series of product advances are made"3 it can be politically incorrect 4o onewants to hear that a smaller number can be better than a larger one

Pi8els and 3ecord -!eed and C+* (0h yJ):

There is a lot of misinformation out there on the sub#ects of pi)el count" CI8 si6es andrecord speeds This paper is an attempt to provide some of the answers

9oriKontal Pi8el Count: The number of pi)els per hori6ontal line varies frommanufacturer to manufacturer 5ou will hear numbers like D>+ us"3 K+> and K2+ ogicdictates that the bigger numbers are better" right? I submit that the (uality is the sameEere's why

The pi)el sample rate is controlled by hardware K2+ are the ma)imum number of pi)elsthat can be sampled on a hori6ontal line with hardware typically used in multi-channel$V%s The K2+ pi)els start at the beginning of the line and end at the other end &ince theends of the line are less stable than the middle" the first eight pi)els and the last eight

pi)els of each line are black

&ince the black pi)els are irrelevant" some manufacturers don't use them" claiming onlythe remaining K+> usable pi)els K2+ minus 1D3 9ith years of e)perience doing this ande)tending the theory that the ends of the line are less stable" some manufacturers ignorethe first forty pi)els and the last forty pi)els on each line" using the D>+ pi)els in thecentrali6ed stable area

There are advantages to the D>+ per line approach@

- 9hen you think about it" the area covered by the D>+ samples is the very samearea covered by the center D>+ pi)els in the K+> and K2+ formats

- The pi)el count and (uality in that area is the same- &ince there are fewer pi)els" the storage re(uirement is smaller- The >)> display using D>+ pi)els allows all individual cameos to be the same si6e

arger formats often run the image off the ends of the viewing area making thecameos at the edge appear smaller than those in the middle

Vertical Pi8el Count: The vertical pi)el count is fi)ed based on the video standard used;ach field has 2>+ scan lines available in 4T&C 8ield based pi)el formats always end in2>+ like D>+)2>+" K2+)2>+3 8rame based formats use both the odd and even interlacedfields from the same camera 8rame based formats will end in >*+ in 4T&C likeD>+)>*+" K2+)>*+3 7A single field will end in 2** and frame will end in GKD

7i)el format review@ 7i)el sample rates are the same" although some manufacturerssample the entire line" some don't 8ull si6e images re(uire all the pi)els to display If you

2K


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capture one field" you have to artificially generate the second field to view a full si6eimage If you capture frames two consecutive interlaced fields3 you will have all theoriginal information for a full image at a higher (uality3" but you will have a larger fileto record with shorter record duration3 and fast moving ob#ects will probably bedistorted due to the time difference between field captures 1BD+ th of a second in 4T&C3

Also with frames" you have to wait to capture two fields" so the record rate is slowerCIF Formats: CI8 Common Intermediate 8ormat3 refers to the si6e of an image

- CI8 or 1CI83 is a (uad si6e image one (uarter the si6e of a full si6e image3 Insome applications" the image is viewed at this si6e &ome applications e)pand CI8images to full si6e by artificially generating every other pi)el both hori6ontallyand vertically The result is lower in perceived (uality than a recorded full image7luses@ &mall recorded file si6e" longer record duration and fastest transfer speed


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7A K2+)GKD K2+)2** D+)2** 1*+)1>>K+>)GKD K+>)2** G2)2** 1KD)1>>D>+)GKD D>+)2** 2+)2** 1D+)1>>

hat C+* siKe is best As is often the case" the answer is that it depends ;ach methodhas advantages and disadvantages If you capture and record a 1CI8 image you have theadvantage of smaller files" longer record durations and smaller si6e files to transmit to

2F


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remote software The disadvantage is that you have less real information to work with Todisplay a 1CI8 image as full screen you must internally generate additional pi)els in bothdirections every other pi)el hori6ontally and vertically3 &o the e)panded (uality is notgoing to be as good as a captured >CI8 image displayed in the same area If you capture a2CI8 image there is less information generated for display vertical pi)els only for full

screen display3 >CI8 images are already full images

A >CI8 image sounds best if the highest (uality image is your ma#or concern 8urtherreview shows that there are drawbacks to frame recording 5ou have very large file si6estaking a large amount of disk storage space" reducing record duration and re(uiringconsiderable bandwidth to transfer images to remote locations The drawback that youmust see to appreciate is the separation of moving ob#ects in the image &ince you arecapturing two consecutive images from the same camera that are separated in time by1BD+th of a second" a fast moving ob#ect will show tearing in the image To visuali6e this"imagine that you painted a delivery truck on a closed set of mini-blinds The slats of the

blinds mimic the interlaced fields of the image 4ow move every other slat three inches

to the right The resultant distorted image is what you might see with >CI8 image captureThis distortion might show up in the live display as well" depending on how the liveimages are processed 5ou might be able to filter out some of the moving ob#ectdistortion" or use a .deinterlacer0 separate and realign the fields3" but I haven't seengood results yet CI8 This is something we learned thehard way from a previous product that used >CI8 3 Image (uality" file si6e" recordduration and bandwidth re(uirements are a good tradeoff providing the most workablesolution for CCTV applications

!n Intelle) our ACC compression uses 2CI8" although it will work with any format Infact" Intelle) I7 uses ACC in all formats This proprietary compression scheme greatlyreduces file si6e by recording only the moving portions of images and employingsophisticated noise-filtering algorithms The result is a compression designed for CCTV

providing a smaller average file si6e with high image (uality

CI8 &i6e@ Image Huality@ 8ile &i6e@ %ecord$uration@

Jandwidth%e(uired@

!verall@

1CI8 owest &mallest ongest east Jest if image(uality is not a

priority2CI8


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3ecord -!eeds: 8ast record speeds are now commonplace 4umbers like >*+ by >*+seem to roll off the tongue ust a short time ago" numbers this si6e referred to the number of pi)els in an image 4ow they refer to live update speed and ma)imum record speed aswell" leading to the resultant confusion A true >*+)>*+ $V% would produce live updaterates of >*+ips and total record rates of >*+ips The result is a real-time 1D-channel $V%

;ive u!date s!eeds: 8or a marketer touting a >*+)>*+ $V%" the first number refers tothe total number of live camera updates per second If you are recording single fieldsfrom a camera" the ma)imum updates you could have from that camera is +ips 4T&C"2Gips 7A 3 The >*+-number refers to a >)> live display on a 1D-channel $V% ;achindividual cameo in the >)> display is updating at a rate of +ips If the $V% has fewerthan 1D-channels" you could only have a ma)imum of +ips per camera &o a F-channelma)imum is 2K+ips &o make sure you are doing an .apples-to-apples0 comparison whencomparing numbers

3ecord s!eeds: 8or the same >*+)>*+ $V% mentioned above the second >*+ refers to

the ma)imum number of images that can be recorded each second 8or field basedrecording the ma)imum is +ips per camera &o this >*+ refers to +-recorded images per second for each of 1D-channels

There are a few units that can actually display and record at these speeds This is doneusing a 1CI8 2+)2>+3 image 9hen 2CI8 and >CI8 images are processed the speedsare reduced The best competitive units are getting better all the time Today's numberslook like this@

- 1CI8 record ma) is +ips per camera- 2CI8 record ma) is K 1Gips per camera- >CI8 record ma) is G K Gips per camera

!ne unit in particular will allow you to configure the record rate per camera 1- +ips at1CI8" Kips at 2CI8 and Gips at >CI83 CI8 and all others at 1CI8 &ome say they do things that don't reallyhappen *+ but actually do less with inconsistent updates that are not evenlyspaced %est assured that all are getting better 9hatever lies are told today seem to cometrue the following year

;ven the best I've seen won't play back a >)> multi-screen in real time Individualcameras record and play at +ips" but multi-screen takes a few seconds to playback onesecond's worth of video All the images are there when you single step through them" butthe multi-screen display doesn't have the processing horsepower to keep current 9ait tillne)t year

This is the story as of today The future will provide rapid improvements+>B+KB+G

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Addendu &: EPicture 7ualityF is a very old document that can shedsome light on the different (uality measurements mentioned by various manufacturers

7icture Huality@ A 7i)el is worth a thousand words/

And it could take a thousand words to e)plain the various terms used to describe the(uality of a CCTV image There is a lot of confusion out there 5ou hear terms likeS &can

ines" TV ines" ines of %esolution" $igital Images" Analog Images and 7i)els 9hatdoes it all mean?

CCTV is an industry in need of standards


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. ines of %esolution0 is an after the fact visual appraisal of the video picture based on theability to distinguish between alternating black and white lines as they become smallerand closer together

If you have grasped this concept" then you already know what .TV ines0 are They are

the same as lines of resolution The terms are used interchangeably TV ines havenothing to do with &can ines

.&can ines0 are the individual electron beam tracings on a television" or" monitor Thereare a total of G2G lines in the 4T&C format consisting of odd and even fields at a rate ofD+ fields per second + frames in a 2@1 interlaced format3

:p until now" we have been referring to .analog0 pictures Jy that I mean pictures produced in the traditional television format Tube cameras" VC%s and TV monitors alldid it this way Contemporary CC$ cameras and computer monitors use digital pi)elsVC% technology and TV monitors are still analog

;nter digital electronics into the picture/

There is only so much you can do with an analog picture 9ould you like to see two pictures on the same monitor? 5ou can use a switcher to alternate two images" one at atime 5ou can use an analog splitter to overlay one image on another This produces either two tall thin images" or" two short wide images In order to get four symmetrical imageson one monitor we need to perform some digital wi6ardry

9ith digital electronics" we sample a scan line some number of times 9e continue tosample additional scan lines This provides us with a matri) of the make-up of theoriginal picture in digital format 9e can then discard some of the pi)els bothhori6ontally and vertically" perform some color changing magic to compensate for lost

pi)els" convert the image back into 4T&C format and then place four" nine" or" si)teenimages on the same monitor $o you lose some picture (uality with each transition fromone form to another? 5es you do These are basics of how resi6ing is done The

particulars of how this is done make all the difference in the end result &o" what is a pi)el?

A .pi)el0 is a picture element This is the smallest portion of a digiti6ed picture whichcan be changed If you have ever taken a close look at one of those spectacular mosaictile murals in a nice


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7i)els are the total number of individual elements across the picture or top to bottom3%emember that ines of %esolution are measured across three (uarters of the hori6ontal

picture KG, of the total distance3 The theory is that each pi)el can display an alternatecolor line

9hat is the best combination of e(uipment to comprise a CCTV system? This could be along debate ;ach manufacturer will say that their e(uipment is the right fit for the rightapplication Is the end user willing to pay any price to get the very best e(uipment on themarket today? $on't count on it &ometimes doubling the price will only get you a smallincrease in (uality The real test of how good the final picture looks is to do side by sidecomparisons Jig numbers for lines of resolution and large numbers of pi)els don't countfor much if the final result is a fu66y picture The (uality of the image produced by anyindividual component in a CCTV system is directly related to the (uality of the image

provided by the proceeding component in the system All components are important Theoverall image (uality is most limited by the weakest component in the system et'sdiscuss each component in a small CCTV system one at a time 8or this discussion" we

have cameras" a multiple)er" a VC% and a monitorCameras@ As we now know" almost all cameras produced for CCTV today are of the CC$type This means that they are digital devices" meaning that the camera captures imagesin a pi)el format and then converts it to 4T&C composite video3 &ince cameramanufacturers are used to rating their devices in lines of resolution" they still do that andalso rate them in pi)els If you use your calculator and compare the lines of resolutionand the pi)els" you will see that lines of resolution are nearly e(ual to KG, of thehori6ontal pi)els If not" somebody is obfuscating the numbers

enses@ $on't forget lenses If the image is not presented to the CC$ pick up device ofthe camera accurately" everything else will suffer Mnow what you will be looking atConstant indoor lighting can provide good images from an ine)pensive camera !nce youventure outside" a low lu) level is re(uired to provide ade(uate images in low lightsituations The general rule is" auto iris in varying light conditions and fi)ed lenses inconstant light indoors3


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;ven in the relatively simple system in our discussion" the video image has undergoneseveral separate transitions 9hich is the most important component in the system? Thereal answer is that they are all interdependent $ue to the technology used" the recordingdevice is usually the most limiting factor

&o" what have we learned? There are different methods used to e)press the (uality of avideo image .7i)els0 are used with digital devices . ines of %esolution0 are used withanalog devices .TV lines0 are the same as lines of resolution 5ou can convert from.7i)els0 to . ines of %esolution0 by multiplying 7i)els by KG If you run into someonewho wants to e)press their output in

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