Anpr

[digital-eye]

Got a customer looking to have some sort of ANPR. Doesnt have to be the logging software but just something that can capture a number plate at night in an industrial estate with street lighting. He has a Geovision capture card in his PC with a dome cam zoomed into a small area but any cat traveling at speed then theres not enough FPS. Any ideas?

[kensplace]

Best option would be a real anpr camera from the likes of extreme, but they dont come cheap.

DIY route you would need to ensure the camera is set to a fast shutter speed, if its to low the plate will probably be blurred/suffer from interlace problems at speed.

You may experience problems with headlights etc, real anpr cams usually block visible light and rely on IR illumination I believe.

Try a different angle also, maybe higher up for the cam, see if it helps.

[arfur mo]

if possible, depending how the camera is setup (as above) you can get fair results if you slow the vehicles down to a crawl with traffic humps, electric barrier even if it simply lifts on approach after a short delay or a chicane etc.

regs

alan

[digital-eye]

Im going to upgrade the to a standalone DVR probably an Apollo, cos the Geovision keeps freezing. So, any particular camera you could recomend? Its a main road so they cant put in any traffic measures im affraid.

[camullins]

Im going to upgrade the to a standalone DVR probably an Apollo, cos the Geovision keeps freezing. So, any particular camera you could recomend? Its a main road so they cant put in any traffic measures im affraid.

If it's a main road should they really be Using ANPR???

I have setup a simlar system myself.

I used a Vista VPC420 with IR lighting.

I had a gate with the camera mounted about 1mtr from the floor on the R/H side which gave the best results.

[james.wilson]

its not the fps that are the problem, its the shutter speed on the cam doing the capturing. There are tables that tell you what shutter speed to use at a particular vehcile speed but for 40 or below you need 1/250 - 1/ 500. Just use a decent cam that allows shutter speed increases.

This wont help low light plates but will solve your vehicle speed problem, but for a general purpose plate grabber look at the derwent reg cams

[digital-eye]

OH, excellent guys thanks!

[NitroN]

I had a similar situation, but on a slower road, so I'm not sure it will work for you.

I used a Samsung 2305 Camera. Initially I had problems because I was using an aspherical lens, which was letting in too much light and the number plates were blurred. I changed the lense to a normal one and hey presto - a perfect number plate picture (from the front - with full headlights)

Its not the DVR that you should be concerned about initially, its the camera and the lense.

I suggest that you use a camera with wide dynamic range... Perhaps you should also try to capture the rear number plate.

NN

[satsuma01]

its not the fps that are the problem, its the shutter speed on the cam doing the capturing. There are tables that tell you what shutter speed to use at a particular vehcile speed but for 40 or below you need 1/250 - 1/ 500. Just use a decent cam that allows shutter speed increases.

This wont help low light plates but will solve your vehicle speed problem, but for a general purpose plate grabber look at the derwent reg cams

redbull have you any links to the table you mentioned above.

[Alpat Systems]

When a customer asks for ANPR, we usually suggest using a dedicated system. However we have succesfully used Samsung SHC-735 and SDN-550 with IR lighting (there's more to it though than simply choosing a camera and lens!!)

Have a read on this thread......

http://www.thesecurityinstaller.co.uk/comm...mp;#entry163109

......and these website's

http://www.licenseplaterecognition.com/

http://www.cctv-information.co.uk/constant3/anpr.html

....and if you decide to go with a dedicated ANPR here's some to consider

http://www.derwentcctv.com/home/index.php?...5&show=true

http://www.vista-cctv.com/vnpr.htm

http://cbceurope.co.uk/CCTV/prodimages/RSC_Kits.pdf

http://www.appian-tech.com/products/anpr-cameras/stinger

http://www.dedicatedmicros.com/uk/netvu.php

http://www.genetec.com/english/solutions/a...u/overview.aspx

http://www.geovision.com.tw/english/3_1.as...pgid&pno=28

http://www.security.honeywell.com/uk/video...npr/168975.html

....and a bit more info

The size of a UK license plate on cars and commercial vehicles is approximately 510mm long x 110mm high. Motorcycles are different being approximately 255 x 200. However more significantly, the minimum height of the letters must be 79mm. The current UK font is Charles Wright, although there are some illegal formats seen. The size of the number plate and the actual characters will need to be of a certain size when seen by the camera for the OCR software to function. One line of thought is that the number plate should be 18% of the scene width; I prefer to consider the vertical height of the characters, which from previous research should be 3% minimum for a 400 line camera. This in fact equates very closely to the 18% screen width but is more logical when considering different shapes of number plates. (For instance when a car plate is 18% of the screen a motorcycle plate would only be 7 %.) Also note that motorcycles currently do not have to carry a front number plate, but this could change in the future.

This provides the first convenient way to calculate the lens angle. For 79mm high characters the scene height needs to be 2633mm. (79 being 3% of 2633). Therefore using a scene height of 2.633M and the known distance, it is a simple matter to calculate the lens angle and thus the focal length. At this stage the height of the camera has not been considered but would not make much difference for normal combinations of distance and camera heights. For an accurate and simple method use the LensCalc software and the top half of table below. The following table shows the lens angle for various distances and a scene height of 2.633M

Distance to target 5M 10 15 20 25 30 35 40 45 50

Lens angle 29.5