ALPR setup advice (see pictures)

J

joshwah

Pulling my weight
Apr 25, 2019
306
147
australia
So I am on a busy street with thousands of cars that go past per day. As a fun experiment I'd like to try out some ALPR detection.

The biggest issue I am going to face is this.... distance. My house is approximately 25m (80ft) from where the cars are on the road.

I've got an existing 4mp camera which can pickup the plates based on the current positioning, but it is simply too far and the image is too pixelated. See: Screenshot (that is with digital zoom applied)

My other issue is, even if I put an 8mp camera in the distance of the IR may be too far for night stuff?

My other thought is, my caravan is always sitting out the front on the road as per the following picture
prnt.sc

Screenshot

Captured with Lightshot
prnt.sc prnt.sc
-- I could easily install a 4/5mp IP camera or similar inside the window of the caravan and point it out to pickup the plates? That would mean both incoming and outgoing vehicles would only be a matter of metres away from the camera and could even get an ID of the driver??? sounds awesome. My issue with this approach is, power. How can I possibly power the camera 24/7? My thought is to run my "REOLINK C2" which is wifi 2.4/5ghz, 3x optical zoom and 5mp to stream directly.. but again, how can I possibly keep it powered? The official specs state the power is Power Input 5.0V/2A, <6W. Any ideas?

Thanks heaps.
 
ok so i've just tested it... and the Reolink C2 can run off my 20,000mah power bank!!!! wow.... am I calculating it correctly that based on 20,000mah and <6w power, it should last 100 hours between charges?
 
Forget about megapixels, use LOTS of zoom, the more the better, probably a 12-20mm lens. I would mount it on the house somewhere, point it straight down the driveway towards the tree.

When you say ALPR, what exactly do you mean ?. My suggestion will most likely allow you to read the plates but probably won't be good enough for an automated system.
 
joshwah said:
okay.. change of plans.... no matter what I do, the footage is soo blurry, even with 25fps :-/
Click to expand...

To pick up plates, chasing MP and FPS isn't where it is at - it is in shutter speed and a tight optical zoom.

If your camera does not let you zoom in tight enough optically (not digital) to have a very narrow field of view to catch basically just the car and if your camera does not let you manual set the shutter, you will not get plates, especially at night. A wifi 3x optical zoom camera at the distance you are at will not cut it.

A camera to capture plates is just that - simply to capture plates - it cannot be used for any other purpose like to get a wide angle shot of the area - it has to be zoomed to the plates optically. At night time, your image will be completely black and all you will see are head/tail lights and the plate - nothing else. You need a fast shutter to do that and a camera on auto shutter will never get you that at night.

8MP at auto shutter at 60 FPS will give you useless video for plates at night. An analog camera that you can manually adjust the shutter speed to 1/2000 at 8 FPS and zoomed in to just the plates optically will blow away the best IP camera on auto shutter at night for LPR purposes PERIOD (not that I am encouraging analog, but chasing MP isn't where it is at).

Based on your image, I cropped it to what you would need a camera to be able to zoom to optically - if your field of view shows much more than that, you will not be able to read plates especially at night:

1582897575321.png

I encourage you to look at the LPR sub-section for more info. There are cameras that can pick up plates at 140 feet. A lot of people, including me, only run 6-8 FPS on the LPR camera with a quality of 2MP or less.
 
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I am not seeing a choke point here to slow down the vehicles either, so high speed may require that you have less of an angle than a house mounted cam can overcome.
You may want to consider a POE tree mounted cam also.
 
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