LPR Walk Through / Tutorial

kevkmartin

Getting the hang of it
Aug 23, 2015
91
85
Reading through several different threads mentioning LPR applications - and seeing several members achieving success, it would be awesome if folks would share details (beyond which cameras they chose) about the software, systems, and configuration choices they've used successfully. For those who have LPR up and running... what's your workflow?

What is required to get from camera purchase and set-up to a functional LPR system, ideally able to log plates, dates, times and photos?

Has anyone actually set up their LPR system to cue additional actions / software based on specific known plates? Special alerts / actions for "first time seen"?

Enquiring minds want to know!

@nayr
 
I'm working on it, first I been trying to find a reasonable priced camera for residential use... asked once for a dedicated subforum to LPR use so it would not be so spread out and dispersed across the forums but dont think anything happened.

There's 2 basic strategies; easy and hard.. easy is just adding a camera that's capable of manual reading via recordings.. so you have it if you need it.. thats where you should start off because its really not that easy, and if you want to go the hard way.. well then your gonna need some command line Kung-Fu and appropriate equipment, so plan accordingly.

I'll be setting up another LPR camera soon and I'll try to document the process better and make it easier to repeat my experiments.. right now it requires alot of resources but with more clever strategies and approaches I think I can get the full blown project into something a bit more manageable; Ideally I'd like to get all the external crap done on a RaspberyPI that I can turn into an easy to deploy appliance.. instead of a big monster server w/discrete gfx.
 
Well, I already have a dedicated i5 laptop running home automation scripts / services, so that part won't be a problem.

I'm mainly interested in the workflow folks have set up.
 
Ideally you capture the plates and then store them in a database with pointers to the pictures, have it discard dupes but keep the info, date and time seen, then maybe be able to create stats, most seen plate number, etc.

Sent from my Nexus 6P using Tapatalk
 
OK... my thoughts are:

1. Acquire a camera with adequate lens, resolution, and IR to observe plates day / night

2a. Configure (camera? Blue Iris?) such that snapshots are put into a directory for post processing

2b. Possible configuration of ALPR Daemon to monitor stream from camera

For my application, 2b seems the best, as it appears that the Daemon can be configured to send output via URL call; if so, that would be perfect for my perl scrip environment on apache I already have running

3. Take action via script on plates observed (enter into database, log to text file, etc.)

4. Trigger other actions on home automation server - my end goal would be to recognize "known" plates and make appropriate voice announcements on Home Automation system

With that outline, what specific open source or home brew solutions add the needed parts?

Or... what am I overlooking / misunderstanding?
 
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OK... my thoughts are:

1. Acquire a camera with adequate lens, resolution, and IR to observe plates day / night

2a. Configure (camera? Blue Iris?) such that snapshots are put into a directory for post processing

2b. Possible configuration of ALPR Daemon to monitor stream from camera

For my application, 2b seems the best, as it appears that the Daemon can be configured to send output via URL call; if so, that would be perfect for my perl scrip environment on apache I already have running

3. Take action via script on plates observed (enter into database, log to text file, etc.)

4. Trigger other actions on home automation server - my end goal would be to recognize "known" plates and make appropriate voice announcements on Home Automation system

With that outline, what specific open source or home brew solutions add the needed parts?

Or... what am I overlooking / misunderstanding?
With your programming skills I'm sure you could easily set something up using OpenALPR.
 
im running mjpeg stream right into alprd and have a simple program archiving the results in a database; havent coded a frontend for it yet.. really needs it..

openalprd eats up a ton of resources, it'll peg a core at 100% and do it as fast as possible.. all CPU bound I got fairly poor FPS though it on a 4Ghz Phenom Hex core, but with a NVIDIA Cuda card i'm getting 20fps no problem.

openalprd will struggle most at dawn/dusk, thats when you have to test it the most because it looks for high contrast areas and thats the time of least contrast.
 
Well, the camera will be more or less zoomed on the width of the road, so snapshot on motion to a file COULD work, then have a scrip monitor the snapshot directory and send new snapshots to ALPR...?
 
I'd prototype try a simple app that subscribes to an IVS event so you can set an intrusion zone that fires off a snapshot and proccessing w/alpr then dumping in a db.. the disadvantage to that is your at the mercy of timing.. watching the realtime feed is really quick and often yields me multiple snapshots at varying distances for better results (reading around a hitch)

With this I worry someone going really fast will be to far away for reading, gets tricky..
 
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OK... here goes!

I just added an ipc-hfw5431e-z5 to my order with Andy that should ship next week.

For good measure, I also ordered the IR Cannon from nayr's birdhouse project. I'm not sure if it will be needed with this camera, but best to have on hand if so.

Let's get this party started!!!
 
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OK... here goes!

I just added an ipc-hfw5431e-z5 to my order with Andy that should ship next week.

For good measure, I also ordered the IR Cannon from nayr's birdhouse project. I'm not sure if it will be needed with this camera, but best to have on hand if so.

Let's get this party started!!!
Where did you get the IR Canon?
 
I believe this is the approximate "setup" that my camera will have. @nayr, any thoughts on how this vantage will work, once it's done with a proper optically zoomed camera?

This will capture traffic both ways - in and out of a cul de sac starting 2 doors down.

Traffic should be under 35MPH (25 MPH speed limit, and slowing for the cul de sac).
25f7a96c70bd4e9335e024cc90a07616.jpg
 
I just received my IPC-HFW5431E-Z5 from Andy. 2 days from Hong Kong to my door!!!

Some unboxing and a sneak peek at zoom:

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Just a box.

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Getting warmer...

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There she is!!!

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Get out here!!!

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Connections.

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Front lens.

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Full wide.

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Full zoom at same position.

Going outside to play now!!!
 
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Well, I'm a bit frustrated with ALPRD at the moment.

I have my IPC HFW5231E-Z5 set up, and I can reliably HUMAN read plates pretty much 100% at all times if day.

I ended up leaving the camera in black and white mode at all times.

So far, I am having little to no success with ALPR / ALPRD. I have configured the pre-warp (many times) so that I can read a given plate with CLI ALPR.... but for other plates, the recognition is poor.

I'm thinking that either:

1. I need more zoom than the Z5 is providing.

or

2. My capture angle is too steep

Thoughts from the pros?