Dedicated License Plate Cam project

[pozzello]

i don't know that anyone has found a way to 'integrate' the windows binary version of alprd in such a fashion as
to get the performance desired for decent on-the-fly LPR. I played with it a while back and it does work to feed in an image
and get a result, but I don't know enuf about windows development to determine if could be made to continuously pull a stream (say from BI
or mjpeg cam directly). I was under the impression that functionality was only available on the Linux distro, but I wouldn't
mind if someone would prove me wrong about that...

 

[Del Boy]

Nayr's house hasn't even got Windows. All boarded up due to the inherent security risk!

 

[tangent]

i don't know that anyone has found a way to 'integrate' the windows binary version of alprd in such a fashion as
to get the performance desired for decent on-the-fly LPR. I played with it a while back and it does work to feed in an image
and get a result, but I don't know enuf about windows development to determine if could be made to continuously pull a stream (say from BI
or mjpeg cam directly). I was under the impression that functionality was only available on the Linux distro, but I wouldn't
mind if someone would prove me wrong about that...

It's been ages since I last used open alpr myself, but looking at the release change log there have been some recent (last 6-9 months) changes that could have a big impact on performance.

 

[SyconsciousAu]

Nayr's house hasn't even got Windows. All boarded up due to the inherent security risk!

Boards? I don't think Nayr would stoop so low. Zwave enabled roller shutters on the other hand ....

 

[nayr]

^^ wth?

 

[Q™]

^^ wth?

 

[bigbadw]

I am in need of advice. I'm looking for an IP Camera that has 940nm IR (so that the IR is not visible to the human eye) and can capture License Plates at night.

Currently, I have two cameras dedicated to License plate capture as part of my larger 12 camera BlueIris security system. They work great during the day, but if I enable IR, they use the 850nm IR and the RED glow makes them visible and easy targets.

Can anyone recommend an IP POE, License plate capture camera that is designed to use the 940nm IR range? I have an additional 940nm IR light source to provide proper illumination at night.

 

[pozzello]

you can use any cam. your existing cams would be fine. just turn off the built-in IR to stay invisible
and add external 940nm IR...

the issue is that ALL commonly available cam sensors are less sensitive to the 940nm-centered IR than to the 850nm-centered
(which is closer to the visible spectrum and has part of its distribution bell curve in the visible red).

So plan to need 3-4 times as much 940nm IR power as 850nm IR power to get the same illumination.
IE go BIG. maybe try one of these:
https://www.aliexpress.com/item/940nm-IR-LED-Array-Illuminator-Lighting-3800mw-940nm-Invisible-For-Manual-Zoom-Camera-20-100m-15/32578018489.html

Nayr and I have used the 850nm version, and it's quite an IR cannon.
May be your best bet for 940nm without spending big $$$...

 

[nayr]

with mine so far zoomed in both camera and IR the cannon is virtually undetectable to passing vehicles, your only in the FOV for a split second and if your looking directly into it you'll think its nothing more than a reflector.

you need a buttload of light to get high shutter speeds at night, and using something several times weaker right out of the gate is kinda stupid.. say no to 940

 

[bigbadw]

Thank you for your replies.

I may be doing something else wrong then. So far I have been experimenting over a couple years, and have not found the proper settings/solutions yet.

Note: The cameras themselves IR lights are highly visible as you drive toward them at night. (I wish this wasnt the case!) It makes them a highly visible target unfortunately.

As example:
1. Camera 1: I turned off the IR lighting function on one camera (Hikvision DS-2CD2T32-I8). The frame rate is set to 1/1000, Smart IR enabled and captures the license plate great during the day. (30-50 feet away from camera, 12 degree angle of camera toward car). I even put black electrical tape over the actual IR lights on the camera, but NOT on the camera's sensor.
2. My second camera (Hikvision DS-2CD2032-I) has an exposure time of 1/2000 frame rate, Day/Night set to Auto, again, black electrical tape over the actual IR lights on the camera, but NOT on the camera's sensor.

External illumination experiments:
1. 850nm external light placed on the ground, aimed toward oncoming traffic. VERY visible, but doesn't allow any night time License Plate capture to take place. The image shown through BlueIris is black and then you will see the headlights of the vehicle coming and going (all in black and white of course).
2. 940nm external light source. Again, no image captured. Same black screen at night, with only headlights being visible.

As a secondary check, I have a camera on the front of my garage facing forward toward the street. I have all the IR's on and the red glow is visible. It clearly shows the external 850nm light source (wide angle light) doing a great job of illuminating the area. It barely shows the 940nm light working. (I didn't expect it to do much at that IR range).

Given how I am setting these up, any changes I can make to my existing cameras that could allow them to work at night? I can provide all the settings I have done on the Camera's themselves if it will help figure out how to utilize either of these two existing cameras!

Question: Do you folks capture night time license plates?

 

[nayr]

Question: Do you folks capture night time license plates?

without problem from 180ft distance, using an Adjustable Focus IR Cannon like this: https://www.aliexpress.com/item/CCTV-5-90-Adjustable-Focus-4500mW-Surveillance-IR-Illuminator-LED-Array-850nm-10-100M/32408878337.html

because its adjustable focus, you aim the spotlight directly at the target area, if your not in the target area you wont see the lights.. most IR Illuminators are wide-angle, meaning anyone infront of em can see the glow and they are not putting the light where you really need it.. on the plate. the IR cannon is on in both pictures below, but unless your in the 5 degree FOV you cannot tell.

how far away are you putting your illuminators? you wont fire up a retroreflector if you put your illuminators too far away from the lens.. the closer the light source and lens the brighter the reflection will be.

 

[bigbadw]

That night time picture of the license plate is exactly what I'm trying to achieve, alright!

The external wide angle illumination is easily 10 to 15 feet from the front of the passing vehicles.

What frame rate do you have the capture set to? Is it slower than my 1/1000 or 1/2000 at night? (This would allow for more light to be captured).

I'm thinking it is the cameras themselves that are my problem, since they work so well during the day.

 

[nayr]

I am running 1/500, I can also run 1/1000 but some dirty plates wont get read.

 

[bigbadw]

I am running 1/500, I can also run 1/1000 but some dirty plates wont get read.

Thanks nayr. I have ordered the IR illuminator and will try the 1/500 rate. It will probably be quite some time before the light arrives (china shipping), but I will report back.

 

[nayr]

from 15ft it might be too much light I suspect heh, guess we'll see..

getting plates at night is no easy task, first you have to abandon all hope for getting anything other than plates.. then for oncoming plates you have to get them as bright as headlamps are @ 1/500 or better.. depending on angle of attack, speed, zoom, etc this can be a total bitch.

When I asked how far away your illuminators are, I mean how far away are they from the camera? not the target.. it has to be ontop of the camera basically.. if you put the camera over here, and the IR light a few feet away.. it wont fire up the reflective plate.. deviate more than a couple degrees and it wont work.

 

[bigbadw]

from 15ft it might be too much light I suspect heh, guess we'll see..

getting plates at night is no easy task, first you have to abandon all hope for getting anything other than plates.. then for oncoming plates you have to get them as bright as headlamps are @ 1/500 or better.. depending on angle of attack, speed, zoom, etc this can be a total bitch.

When I asked how far away your illuminators are, I mean how far away are they from the camera? not the target.. it has to be ontop of the camera basically.. if you put the camera over here, and the IR light a few feet away.. it wont fire up the reflective plate.. deviate more than a couple degrees and it wont work.

Damn, I have been doing quite a few things wrong for sure!
Current configuration: One camera is mounted up on the side of a large tree. The other is on the opposite side in a "bird house". Both are easily 20-30 feet diagonal from where I placed the external light sources. The external light sources I have used so far, are then about 10-15 feet from oncoming or passing cars.

What I have learned from you so this dialogue so far:
1. My existing cameras should work fine.
2. I need to experiment and see if a frame rate of 1/500 will work.
3. The external illumination device I had was wrong (wide range vs. the focused devices you use)
4. The placement of the external illumination needs to be placed by the camera, focused down the same angle.

Thanks for letting me know that this a difficult in the first place. I am dedicated to getting a solution. (my last tough one was getting microphone/speaker working on a front door camera. That was easy compared to this problem).

Please let me know if I missed anything you have recommended. Again, appreciate your help!

 

[bike_rider]

Nayr is on the mark, especially about the IR being on axis with the camera and a dedicated camera. For my setup, my cameras are pretty far off the center line of traffic, so the LP cam only gets a small window of time to take a shot. I have to use a wider field of view camera covering the same area (plus a lot on either side) as a trigger camera. The wide camera (good for people) uses motion detection. When it triggers, it fires off the LP camera too. Otherwise the lag on the LP camera response misses things.

 

[bigbadw]

The IR light finally arrived from China. (your recommended purchase of:
https://www.aliexpress.com/item/CCTV...408878337.html )

I'm having a heck of a time with my Hikvision DS-2CD2T32-i8. I'm unable to get the exposure rate to be 1/500. Currently, it is set to common (manual), Daytime 1/2000 and night time 1/1000. Nothing I do can change any of those settings. I can select different exposures, but there is no SAVE feature enabled on that page. I've exhausted all that I know of.
Anyone else have a problem getting those settings to change?

So, this weekend I will experiment with placing the new IR illuminator on the camera.

I have a second Hikvision DS-2CD2T32-i4 that is still in its box. I may build a camera set up with it, and only have it set to 1/500 from the beginning. (I hope).

 

[nayr]

might try resetting it to defaults, could be another feature you have enabled that is limiting the shutter speed.

 

[bigbadw]

I like it! Thank you, I will give that a try!

How did you get the "frame of view" to be so small? I tried to do that within Blue Iris, but the image captured and video captured stayed the same as the camera view (larger than required to capture just the license plate).