Hello - LPR sanity check

nypogodi

nypogodi

n3wb
Nov 2, 2019
6
2
Seattle, WA
Hello everyone,

I found this site after deciding to get a camera for LPR to supplement my Unifi Video system. Unifi has been running for years with no issues. When stuff happens in view of the cameras, all I can do is watch the cars drive away. I usually don't rush into projects like this without more research and a solid plan, but this needs to be done sooner than later so I'm learning on the go. I've been reading about LPR on this site over the last week and ordered a IPC-HFW5231E-Z12E from Andy's Amazon store. Received it today, feels like a solid quality camera, I plan to set it up this weekend.

My current plan is to connect it to OpenALPR Watchman service to capture plates of cars driving through our community. The goal is to start capturing plates ASAP in case something happens, and then figure out what and where to optimize. There is some 1000/month plate limit in the OpenALPR, so I'll need to figure out some way for the system to be sustainable and capture about 3000 plates per month. So many ideas, so little time! o_O

Camera position: Camera will get a direct view of cars turning a corner 90ft away, looks good in IPVM. Low volume, counted about 100 cars passing in the last 24 hours, so estimating 3k-5k plates per month.
Powering the camera: Unifi US-8-60W 8/4 PoE switch (802.3af). This should work since the Z12E is also 802.3af.
ALPR software host: Haven't figured this out yet. I have an old Intel i3 PC which I plan to try running this on, could run Windows or Linux, haven't decided yet.
Camera settings for day/night: No idea yet, but I've seen many posts that had examples, so I haven't spent time digging into this yet.

Am I missing anything important? I know I'll bump into whatever it is sooner or later as I'm setting everything up. If anyone has any comments or suggestions, I'd love to hear them!

Thanks,
Tony


P.S. - I wish I had found the cliff notes sooner...
 
I have the 5241E-Z12E running on the US-8-60W so, it should power it just fine. Curious to see your post implementation write up as I am interested in doing the same setup.
 
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I have a similar 5231-Z12 & 5241-Z12 running LPR duties on ubiquiti equipment as well

mikeynags said:
I have the 5241E-Z12E running on the US-8-60W so, it should power it just fine. Curious to see your post implementation write up as I am interested in doing the same setup.
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As you probably saw already, night LPR photos tend to be very dark. An overview camera that gets vehicle body descriptions at maybe 1/100th to 1/250th-second shutter speed, would make a good companion if you don't have something already planned for that role. Details like body damage, hubcaps or rims, stickers, even the position of roof-rack crossbars, can be valuable if something serious goes down.
 
mech said:
As you probably saw already, night LPR photos tend to be very dark. An overview camera that gets vehicle body descriptions at maybe 1/100th to 1/250th-second shutter speed, would make a good companion if you don't have something already planned for that role. Details like body damage, hubcaps or rims, stickers, even the position of roof-rack crossbars, can be valuable if something serious goes down.
Click to expand...

Currently my Unifi-G3-Dome is the overview camera, at least for now. Unfortunately it isn't pro enough to have adjustable shutter speed and won't pick up all those details at night. I got my Unifi Video system a few years ago, and it was a very easy plug-and-play out of the box. If I was to get a more fitting overview camera, it won't record to my Unifi NVR, but I'll have to make a small Blue Iris(?) system just for that camera. Any suggestions?
 
nypogodi said:
Currently my Unifi-G3-Dome is the overview camera, at least for now. Unfortunately it isn't pro enough to have adjustable shutter speed and won't pick up all those details at night. I got my Unifi Video system a few years ago, and it was a very easy plug-and-play out of the box. If I was to get a more fitting overview camera, it won't record to my Unifi NVR, but I'll have to make a small Blue Iris(?) system just for that camera. Any suggestions?
Click to expand...
For your overview camera, if cost were not an issue, perhaps one of this model, with the fairly long-range lens, 4MP 1/1.8" sensor and a reputation for good low-light performance: US $240.0 5% OFF|2019 New Arriving cameras IPC B5442E Z4E 4MP WDR IR Bullet AI Network Camera free DHL shipping-in Surveillance Cameras from Security & Protection on AliExpress - 11.11_Double 11_Singles' Day Or just another Z12E like you've already ordered, but tuned for overview duty. Can you post photos of your camera-mounting options on your building, and your target zone?

What generation of i3 is your rig equipped with? I have a retired i5-2500 sitting on my table here. If that jives with your motherboard, I could just mail you that no charge. Four actual cores plus Turbo is a step up from an i3. I'd think it could cope with two cams, BlueIris, and OpenALPR Watchman with one 1080p LPR feed at 15fps to get you started. There's a BlueIris wiki hereabouts for optimization steps, which you may already have seen.

I have OpenALPR processing a 5MP feed at 30 frames per second, which is out-of-bounds even for my i7, which gets the assist it needs from an nVidia GTX1050 doing the OCR work using CUDA. Whatever route you go, brace for a lot of initial frustration and trial-&-error as you figure out what settings tweaks will get you the results you need.
 
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I haven't decided on an overview camera yet, will worry about that in Phase 2, after the first camera is recording license plates. Like you said, I'll have my hands full with figuring out settings for my setup. The camera has been mounted today, took longer than expected because I didn't realize that the camera mount only has vertical adjustment so I had to make a 30° wedge, run Cat6 cable, etc. The target zone is about 100ft away. I'll attach more photos tomorrow, as it was getting dark when I was finishing the install.

The PC has an i3-2100 so your i5-2500 should be compatible and should be a 45% boost according to UserBenchmark. I have no experience with any of this (LPR, BlueIris), so I can't speak to the actual performance until I actually try it. I may need to get a GPU to make it work properly.
 

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I have a slightly older variant of your camera and found a good start in this thread: IPC-HFW5231E-Z12 LPR from 137 feet The older version of the camera has an iris that can be manually adjusted via software if desired, so roll with the punches on that one. I ended up using it for something else, for reasons of my own, but it was a contender. Send me a private note with the envelope icon up towards the top-right with your address (work address is fine if you prefer that I not come and steal your camera :) ) and I'll shoot that i5 over to you next week.

What's the ambient light like in the target corner? Maybe set the cam to AUTO and post us a photo of what your overview cam will be seeing out there. In my capture zone, I have a streetlight overhead and beyond the vehicles, so I tend to get silhouettes.
 
Yes, I've seen that thread, and I am referencing it for my setup. The target corner is pretty dark. I have a LOT of playing with settings ahead of me! Camera settings, BlueIris settings, etc...

Below I pretty much copied the night profile from that thread.
lpr1.20191110_190438731.jpg

But on the bright side, the troublemakers that prompted us to get this camera came back yesterday so I got their LP and had the Sheriff go talk to them! :D

20191109_125536 - redact.png
 
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muwahaha!!! Karma! :D

I snipped out the approximate plate size, they're around 70 pixels wide at your current zoom. For LPR work, gun for plate sizes to come out at 100-150 pixels wide, to give your LPR a better chance on the tricky characters like D versus 0 versus O versus Q. At least they're Washington plates, not Idaho with their tiny letters...

If you haven't gotten around to it already, also check what bitrate your camera's using. Nothing to lose by dialing it up to 12000 Kbit/sec or more, so the camera has all the headroom it can want when there's lots of detail in the scene.

1573448607493.png
 
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I need to move the camera down a little to zoom in any further. The roof ledge is in the way! That photo is probably at 3x zoom.

I'll try the higher bit rate, but i think the blurry plates are due to exposure settings.
 
The camera is also known for goofing up your focus setting when it flips from day profile to night. With the LPR tuning, the scene is too dark for the camera to auto-focus at night. The guys in the LPR forum have a couple of strategies. One is to leave the LPR cam in black & white mode 24/7. I never got around to trying that, but it sounds like a legitimate opening move. I think @bigredfish said he has several of these set up that way. Here is more discussion on another strategy: IPC-HFW5231E-Z12E High Zoom Auto Focus Work Around
 
I was just looking at that, and yes, the camera has focused on the car parked in the driveway, not on the road. So I'll need to adjust a couple things.

1. Re-position the camera down a little
2. Zoom in to get more pixels on the plate
3. Capture zoom and focus into DahuaSunriseSunset utility
4. Play with nighttime exposure settings for my scene

One thing I've noticed is that the IR Light settings don't change when switching between Day/Night profiles. Has anyone else experienced this? I currently have this set to Mode ZoomPrio with correction 100. Once the camera is in a good place and focus is stable I'll tinker with IR.
 
If either profile (Day or Night) is set so the camera can opt between color or black & white depending on the scene, then your current IR setting would allow it to turn on the IR in ZoomPrio mode when it's running black & white due to lighting conditions. If the camera switches from B/W to color mode, it'll shut off the IR emitters regardless since they wouldn't be helping.

I just flipped my Z12 to black & white and here's what it sees now: FOG. And you can see it totally lost focus in the process:

1573458353176.png


Back to color! (it has parking-lot duty)

1573458432905.png
 
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