License Plate Recognition Cameras

[cachecreekcctv 0]

To those of you who have purchased LPR cameras, I would like to ask the question; what actually makes them different from an ordinary CCTV camera? Or does it happen to be any associated software that makes it possible to do a "freeze frame" effect, in order to view a moving vehicle? Since anyone can get enough IR to light up an object out quite far, does the wavelength of the IR illuminator come into play here? It's just that no one I deal with is going to spend upwards of $3000 or more and not be certain of 100% capture rate.

[rory 0]

IR alone isnt what makes them see a Licence Plate. In fact if you just point IR at a car you typically will never see the licence plate at all.

 

You need a camera that blocks all the additional light and cuts back the glare from the head lights, while only having the least amount of light on the licence plate area. I dont make the cameras so cant say more than that, besides we tried numerous expensive brand names, normal spotlights, etc, and in the end the specific LPR cameras made life so much easier, and they worked right out of the box.

 

If you have alot of time to play with the app and spend at the location, you could try a wide dynamic camera like the Pano Day Night, with some spot lights, but you need to have alot of different bulbs with you as it will take plenty of adjustments. Optionally use IR but get something that allows you to adjust the level of IR or you will have to move it around alot. Also, the normal glass cover should be replaced with some kind of dark tinted glass, or perhaps some strong filters. Personally the time involved in that, it is cheaper for me to buy a LPR camera one time.

[CollinR 0]

It's pretty rare when you can get 100% capture, toll booths and drive throughs do pretty good. Basically in OK if they are pulling a private trailer there is a good chance you won't get the plates, same for 2nd car following close. We have no front plates here, maybe different where you are.

[cachecreekcctv 0]

So, do you believe that most, if not all LPR cameras are of the WDR type? Has anyone here actually taken a LPR camera apart to see what makes the difference? My DVR capture quality is set at its' highest, which is actually only around 15fps at best. Wondering if capture frame rate also helps in the scheme of things?

[rory 0]

The Extreme Reg cameras are not WDR, extreme does not have any WDR cameras.

[rikky 0]

Does anybody know if you'd need 1/2" cameras or if 1/3" CCD's can do the job.

 

thanks,

[Scruit 0]

I'm not a professional, just a home user.

 

 

I have a 1/3" BW CCD camera with a 75mm manual iris lense and 850nm IR filter, plus 850nm Illuminator, that is aimed at the thinnest point in my driveway about 90' from the camera. All equipment source from ebay, and total cost was about $200 for everything.

 

I've also spent probably 20 hours in adjustments and improvements. I've had to do a few long-term tests (ie put a license plate out there and caputre an image every minute for 24 hours then review all the images to ensure caputre under varied light conditions) and I usually review the DVR when someone drives into my driveway to ensure I got the plate (only 3 or 4 cars a month drive into my driveway). It's a lot of trial and error. Mostly error at first...

 

 

I get very good coverage, but there's always exceptions - ie a truck with a license plate that is obscured by mud, or a car that has no front plate (even though they are required here) that drives forward into my driveway and then backs out.

 

 

The performance I get is very good, especially for the money, but it's been much more work than buying a proper LP camera. Definitely an ongoing project, not just an install-adjust-forget thing.

 

 

If you want the best coverage with no fuss then get a real LP camera. If you have the time and enthusiasm to tinker with it for a couple hours each month, and can afford many missed plates for the first few months until you get it dialled in to you local light/weather conditions, then you can probably can get away with a homebrew system like mine.

 

For me, if the only way to capture license plates was a $1500 camera then I would simply not have that function in my system and that kind of money exceeds my after-insurance exposure in a burglary. My system only exists to try to reduce my risk/exposure in a burglay/vandalism situation, and the $$ I spend must be appropriate to that goal. There's no point me spending $10k on a cctv system when my insurance deductable is only $500 (and the insurance only rips me off for another $1000 in 'depreciation'

[rory 0]

20 hours @ $75 per hour = $1500

[Scruit 0]

20 hours @ $75 per hour = $1500

 

My time is cheap.

[rory 0]

20 hours @ $75 per hour = $1500

 

My time is cheap.

 

Yeah me too really .. i is works for free some times ..

[Deluxecctv.com 0]

Hello, there is a company called Extreme CCTV that puts this camera out. These cameras are by far the best out there on the market that I know of. We did a huge install for an auto mall here locally. The application was 15 PTZ'S, 35 fixes cameras, and 2 LPR cameras. I have personally seen the LPR cameras in action.

 

These kids came into the auto mall and vandalized several car lots. The kid’s faces and license plate were caught on video. Thanks to the REG cam, the guys are now caught. They are expensive cameras, but worth the money. If the company that you are installing the REG cams have the money, then I say why not? You don't want to settle for cheap when it comes to catching license plates.

[videobruce 0]

I usually review the DVR when someone drives into my driveway to ensure I got the plate (only 3 or 4 cars a month drive into my driveway).

You have some paranoia about someone pulling into your driveway??

[cctv_down_under 0]

The biggest problem with standard cameras and reg capture is being able to adjust the settigs properly, I am no expert on this but the things I have had to adjust for plate capture are the following.

 

1/ You need a camera that does have problems with vertical smearing, IE those two long thin lines that go top to bottom when headlights are directly looking at the camera.

 

2/ You need a camera that has a fast shutter speed or better still a dynamic shutter speed that adjusts itself to avoid motion blur, keep in mind though that shutter speeds effect the brightness of the image.

 

3/ You need to trun down the gain because the gain when looking at hot white light with distort the image, therefore you need to be able to adjust the gain setting for day and for night, the best way I have found this is to use the IO input/output on a DVR and run a schedule to the camera I use that allows you to switch modes and profiles IE 1 for day and one for night.

 

4/ If using IR lighting then you need an IR correct lense or you may go out of focus at dusk and dawn and IR correct lenses also help with the blooming effect you get with headlights when using IR lighting.

 

5/ There is an alternative option of using cameras that support inversion, this measn the headlights are black instead of white and therefore do not effect the image so much, if the plate has a white or reflective background then the numbers and letters can be made out quite easily in ineversion mode.

 

6/ Lastly if you have a camera that can set a maximum bright level...no not a DC level but a maximum light threshold you can eliminate some of the effects of the headlights in this mannor.

 

 

I hope this helps

[jeffpack1957 0]

The Reg cam's are dependant on two factors.

 

One, correct amplitude of the IR output.(its adjustable)

Two, the reflectivity of the license plate.

 

If a plate is dirty, or old, the Extreme wont pick up a plate.

(in the dark).

 

This info comes not only from personal experience, but from

Extreme's support group as well.

[SBTVideoman 0]

Something else to be aware of - several manufacturers make cameras with a feature called "Peak White Inversion". This feature automatically "darkens" utra-bright sections of the image into a black spot. If used in a LPR application, the feature can automatically darken an automobile headlight, thereby reducing the overall dynamic range in an image. It is not necessarily a purpose-built feature for LPR applications, but can help.

 

Some examples include the CCBC1225 & CCBS1225 1/2" cameras made by Siemens. They are not the only ones. I think Ness in Australia may have has a similar feature on one of their 1/3" models that they call the "Eclipser". Again the intention is to darken the ultra-bright portion of the image to improve the overall result.

 

The Peak White Inversion feature is built into the camera- it does not rely on IR illuminators.

 

It may be something seriously worth considering for LPR applications.

[VST_Man 1]

ok, we know that extreme has expensive models. I am going to install some lower priced LP camera's in a week or two. The C480LPR120 from ARM. Much cheaper. And I also purchased a LPR camera (no lense, no IR, no housing) from a dealer to test..............

 

anyone have any feedback on the cheaper models? They are cheaper and I've heard no bad press on them...........

[cachecreekcctv 0]

Just looking at the Honeywell ACC334TPX now that you mentioned the White Inversion. Need to follow up on that one. Thanks

[rory 0]

Never seen any cheap LPR specific cameras, just WDR cameras and others with some hacks to work with plates .. or more so claims by sales reps.

[cachecreekcctv 0]

Spoke to a friend of mine today, who told me that he has used the Ademco ACM574 for this same purpose (plate capture) . I asked him why he never told me that before, and he stated " I don't have many calls for plate capture....I forgot". I think Ademco is now Honeywell? Will look into this further.

[cachecreekcctv 0]

Was told today that the Panasonic CP484?? models have this "Peak White Inversion" switch on them. Since I have never bought one, can anyone on this forum, who has this model(s), confirm this? If this is true, has anyone tried to set the switch to see the outcome at night?

[Lloyd 0]

Was told today that the Panasonic CP484?? models have this "Peak White Inversion" switch on them. Since I have never bought one, can anyone on this forum, who has this model(s), confirm this? If this is true, has anyone tried to set the switch to see the outcome at night?

 

I run a CP484.

I have not run across any setting in this camera that says "Peak White Inversion", or anything similar.

I also scanned over the Operating Instructions, and saw no reference to anything like it.

But I am just a DIYer, and I could be overlooking it.

You can Google for info on the camera, and find a pdf file with the complete Operating Instructions.

[atropine 0]

This sounds intersting. I was thinking of doing something like this for hobbyist reasons. Neighbour had a drunk chick drive into his parked car, then she drove off again. Luckily he was at home and hot her number plate. But that made me think a number plate reading camera could be useful.

 

I'm going to use a old black and white camera and a infra red illuminator. Not sure if that will ever work, but lets imagine it does. What software can I use that actually reads the number plate , converts the picture into the number plate text?

 

Is there any OCR software that will automatically read text from .jpg's when a .jpg is placed in a directory it's monitoring?