How does SPECS work?
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Discussion

andytk

Original Poster:

1,558 posts

295 months

Tuesday 30th November 2004
quotequote all
Question is as title really.

How does the numberplate recognition software work?

Does it link into the DVLA database even if you're NOT speeding.

What does it do if sees a fake (ie, not registered) plate.

What happens if you drive 2 inches from the back of a truck and it can't "see" you. How does it work out your speed if the 2nd camera then see's you?


How infallible is it.


Can anyone answer? These camera's bug me by far and away the most, out of all the speed cameras. (with the possible exception of Talivans)

Andy

s a m

509 posts

266 months

Tuesday 30th November 2004
quotequote all
Uses an ANPR type system, you travel past the first set of cameras (typically a yellow CCTV style camera, with a couple of Infra Red night vision lamps either side.)

The system reads your plate, and stores it along with the time.

Further down the road you are seen by the second camera, which does the same thing.

The system then compares the two times – if you covered the distance in anything less than X seconds / minutes then your average speed was in excess of the limit.

Far as I know it doesn’t do any DVLA stuff, they couldn’t do anything if it flagged up anyway - that’s what the ANPR vans and waiting plod are for. If you were speeding, it just sends or stores the details and probably a still image of the start/end points.

A little cash register noise can be heard ringing from the unit. It calls base with the good news and at some point within the next 14 days, the unlucky driver gets an invoice.

2 Smokin Barrels

32,011 posts

264 months

Tuesday 30th November 2004
quotequote all

s a m

509 posts

266 months

Tuesday 30th November 2004
quotequote all
andytk said:
What happens if you drive 2 inches from the back of a truck and it can't "see" you. How does it work out your speed if the 2nd camera then see's you?

How infallible is it.


If it doesn’t see you at either point then I am pretty sure nothing will happen, they couldn’t calculate the speed without a start/end time.

As for reliability – I am sure they are “pretty good” most of the time, but if the London Congestion Charge ANPR is anything to go by, I would say its bound to have its faults, no doubt misread some plates and thus get it wrong from time to time.

'King Deadly

196 posts

266 months

Tuesday 30th November 2004
quotequote all
s a m said:
Uses an ANPR type system, you travel past the first set of cameras (typically a yellow CCTV style camera, with a couple of Infra Red night vision lamps either side.)

The system reads your plate, and stores it along with the time.

Further down the road you are seen by the second camera, which does the same thing.

The system then compares the two times – if you covered the distance in anything less than X seconds / minutes then your average speed was in excess of the limit.


Much fun to be had, then, getting a couple of identical front plates made up, and arranging with a mate to drive past both cameras at about the same time.

It would clock you at something approaching the speed of light.

How many points is that under the new guidelines?

edc

9,646 posts

280 months

Tuesday 30th November 2004
quotequote all
Does ANPR actually capture an image of the car's reg plate?

I found this www.securitypark.co.uk/article.asp?articleid=190

but it doesn't state that ANPR captures an image but that that is for CCTV.

I was recently in a BP station www.pistonheads.com/gassing/topic.asp?t=140208&f=10&h=0 and ANPR did not 'recognise' my plate although I'm sure CCTV would (since you can read it easily by eye).

s a m

509 posts

266 months

Tuesday 30th November 2004
quotequote all
CCTV and ANPR work together in a way.

The CCTV (camera kit) gives the computer a high quality video stream, the software (ANPR) then analyses the frames looking for a number place (size, shape, colour etc), it then reads the plate in a kind of OCR (Optical Character Recognition) fashion - like most scanners can do on printed documents. ANPR is just a very fast, specialised system for quickly scanning for and reading number plates.

The camera output could be videoed, but I would suspect that the ANPR software stores the frames it used to grab the plate for human verification along with a speed overlay, time, date etc - which can then be checked by a human to make sure its the same car, and ANPR read the plate right.

TripleS

4,294 posts

271 months

Wednesday 1st December 2004
quotequote all
I can see how the specs system is applicable to motorways where, apart from roadworks or other delay factors, it is possible to maintain speeds far in excess of the 70 mph limit. In that case being seen to have averaged more than 70 mph between the two points, subject perhaps to a margin of tolerance, does rather clinch it unfortunately.

However, what about the case of a normal A or B road which would normally be subject to a 60 mph limit. Allowing for the twisty bits and other restraints will often mean that one can not average 60 mph over much of a distance anyhow, even by using extremely high speeds at certain points. How would a trigger speed be selected in such a situation?

Best wishes all,
Dave.

andytk

Original Poster:

1,558 posts

295 months

Thursday 2nd December 2004
quotequote all
Some very interesting info. Cheers guys

Some more of my thoughts.

The London KenJesting Charging is ANPR based as well.

I'm curious. If it spotted a number plate which is total rubbish (ie, fake) does it simply log it in its memory and then wait for payment. Would it be possible to make a payment against a non registered plate.

Or, does the system check every plate as it sees it, ie. is it connected to the DVLA database.
Or does it simply wait for someone to not pay and then hands over the plate details for the DVLA to process. So at the end of a day it'll hand over all the plates that haven't paid. And only then would it discover that the plate wasn't registered.


Andy

Plotloss

67,280 posts

299 months

Thursday 2nd December 2004
quotequote all
If you put more than one number plate on the front of your car (completely legal as long as it doesnt carry an index number)

ANPR doesnt know where to look, apparently...

Pigeon

18,535 posts

275 months

Thursday 2nd December 2004
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Now that's an interesting "decoration" idea for Smart body panels...

ginge

2,929 posts

272 months

Thursday 2nd December 2004
quotequote all
Plotloss said:
If you put more than one number plate on the front of your car (completely legal as long as it doesnt carry an index number)

ANPR doesnt know where to look, apparently...


Might be a stupid question but what is the index number on a number plate?

'King Deadly

196 posts

266 months

Thursday 2nd December 2004
quotequote all
ginge said:

Plotloss said:
If you put more than one number plate on the front of your car (completely legal as long as it doesnt carry an index number)

ANPR doesnt know where to look, apparently...


Might be a stupid question but what is the index number on a number plate?


The clue is in the question!

s a m

509 posts

266 months

Thursday 2nd December 2004
quotequote all
what a great idea...

we could all get PISTON HEADS number plate "style" stickers made up. Ted, why not put them in the shop, I'l buy one

hertsbiker

6,443 posts

300 months

Thursday 2nd December 2004
quotequote all
get a plate made up with your cars name/model/engine size/turbo.

Make sure plate does not have BS marks on it, therefore cannot possibly be construed as being a number plate. Attach to back of car where normal plate lives, and put your plate as low as possible. With lights of course.

For front, angle the proper plate downwards slightly, and fix the other plate on the bonnet in prominent location.

Alternately.. the holy grail. If you have an old TVR you can protect the back end very very easily.

Holy grail part 2, corner cube techonolgy is a wonderful thing best left at home. I'll leave that thought with you until next time I post.