Gotcha 3M Printed Plates at Night - LPR

[wittaj]

As many of us have experienced, and well documented in this thread, that the 3M printed plates, especially those with blue in them, are very difficult to get with infrared.

Unlike the stamped/raised plates, these printed plates do not have the same reflective properties and the flat nature of the plate also makes the angle even more important.

As I mentioned in that thread, I have had some success with moving my LPR camera closer, and you do stand a better chance of capturing the plates the closer you can get with them.

It isn't the focal length that is the issue, but rather it is the IR from the camera at 40 feet is tighter and more on the plate than it is at 150 feet.

Or the option is to get a specialty IR blaster with a tight IR beam like 10 degrees as opposed to the typical 60 or 90 degree options on Amazon.

I came across some RayTec and Axton IR blasters, but also white light blasters. They are kinda pricey and I was hesitant to buy one if it didn't work because you cannot return.

So when my back floodlight went out, I thought what the heck let me try a white one and if it doesn't work for LPR, then it is an expensive floodlight LOL.

Axton has a 10 degree white light unit that will pulse with the shutter speed, but in addition to the cost, if it became a floodlight, it doesn't have a lot of dispersion LOL.

RayTec has a different approach and sells units with interchangeable filters that will allow you to get 10 degree, 35, or 60 degree standard with the purchase, with optional ones for 80 and 120 degrees.

So I went with the Raytec because it was cheaper and had more flexibility for another use if it didn't work out.

WOW - this thing is a light cannon. Like a tug boat light.

I first tried it with using the motion detection of the camera to trigger it using the alarm out wires that come with the @empiretech B52IR-Z12E-S2 (5241-Z12E-S2) camera, the standard camera for many here for LPR.

As expected, due to the tight field of view for LPR, the lag of IP cameras would cause the light to come on after the car was beyond the field of view.

Since I am using Blue Iris, I am using the T180 camera, along with the new features of BI that I mentioned in this spotter camera thread to trigger the white light connected to the Z12E and then use the motion detection of the Z12E to turn the light off.

Let's just say it exceeded my expectations! In most instances it is simply like a flash camera. I know it is there and I never see it while driving in that zone. Someone would have to be turned around looking at it to see it flash. Some out walking may think it was a lighting flash LOL.


Not only am I getting the plates, I am getting 3M printed plates with clear covers over them:



Compared to Infrared:



But I was surprised that I even got a 3M printed plate with a dark cover on it:



I was hesitant to spend that kind of money, but in the end the RayTec was about the cost of a camera and the results speak for themselves!

 

[Parley]

As many of us have experienced, and well documented in this thread, that the 3M printed plates, especially those with blue in them, are very difficult to get with infrared.

Unlike the stamped/raised plates, these printed plates do not have the same reflective properties and the flat nature of the plate also makes the angle even more important.

As I mentioned in that thread, I have had some success with moving my LPR camera closer, and you do stand a better chance of capturing the plates the closer you can get with them.

It isn't the focal length that is the issue, but rather it is the IR from the camera at 40 feet is tighter and more on the plate than it is at 150 feet.

Or the option is to get a specialty IR blaster with a tight IR beam like 10 degrees as opposed to the typical 60 or 90 degree options on Amazon.

I came across some RayTec and Axton IR blasters, but also white light blasters. They are kinda pricey and I was hesitant to buy one if it didn't work because you cannot return.

So when my back floodlight went out, I thought what the heck let me try a white one and if it doesn't work for LPR, then it is an expensive floodlight LOL.

Axton has a 10 degree white light unit that will pulse with the shutter speed, but in addition to the cost, if it became a floodlight, it doesn't have a lot of dispersion LOL.

RayTec has a different approach and sells units with interchangeable filters that will allow you to get 10 degree, 35, or 60 degree standard with the purchase, with optional ones for 80 and 120 degrees.

So I went with the Raytec because it was cheaper and had more flexibility for another use if it didn't work out.

WOW - this thing is a light cannon. Like a tug boat light.

I first tried it with using the motion detection of the camera to trigger it using the alarm out wires that come with the @empiretech B52IR-Z12E-S2 (5241-Z12E-S2) camera, the standard camera for many here for LPR.

As expected, due to the tight field of view for LPR, the lag of IP cameras would cause the light to come on after the car was beyond the field of view.

Since I am using Blue Iris, I am using the T180 camera, along with the new features of BI that I mentioned in this spotter camera thread to trigger the white light connected to the Z12E and then use the motion detection of the Z12E to turn the light off.

Let's just say it exceeded my expectations! In most instances it is simply like a flash camera. I know it is there and I never see it while driving in that zone. Someone would have to be turned around looking at it to see it flash. Some out walking may think it was a lighting flash LOL.


Not only am I getting the plates, I am getting 3M printed plates with clear covers over them:

View attachment 189421

Compared to Infrared:

View attachment 189418

But I was surprised that I even got a 3M printed plate with a dark cover on it:

View attachment 189419

I was hesitant to spend that kind of money, but in the end the RayTec was about the cost of a camera and the results speak for themselves!

Great information and what a success you have there.

 

[wittaj]

Great information and what a success you have there.

Yeah, not all of us are as blessed with the amount of light you have to be able to run color at night without additional help!

 

[actran]

@wittaj Are you saying that we should do LPR in color now? After pounding into people that nighttime LPR has to be done in B&W with IR?

Any chance your white light can cause some instances where the picture is completely washed out (unusable)?

 

[wittaj]

@wittaj Are you saying that we should do LPR in color now? After pounding into people that nighttime LPR has to be done in B&W with IR?

Any chance your white light can cause some instances where the picture is completely washed out (unusable)?

For those that are from states with stamped/raised plates, IR will still be the better choice due to the reflective property of the plates. Or if you can get the camera close enough to the street you can get the printed plates with infrared. But once you add distance and angle, the 3M printed plates get harder to capture.

But for many of us, circumstances and technology have changed.

When this is the kind of plate we get with the 3M printed plates and infrared, you either accept you won't get as many plates or figure out how to do it color:



To be clear, you still have to run fast shutters to capture plates in color. And most do not have the available light. Look how dark my image is except for the plate.

And some don't want a flashing white light emitting from their house every time a car goes by either LOL.

And someone like @Parley has shown in this thread that the new sensor technology, coupled with his available white light, allows him to capture plates in color.

But look at the available white light he has compared to mine where you still only basically see the plate (or a white vehicle barely).



And yes, my first attempts did wash out the plate and it was all white. Fortunately the RayTec allows you to adjust the power, so I dropped it down along with increasing the shutter speed.

With the stamped plates and IR, I had to run a 1/2000 shutter due to the reflective properties of the plate washing out the plate with a slower shutter.

With the printed plates and IR, I had to slow the shutter to 1/1000 because the plates were not as reflective. But much slower than that and they are a blur.

With the RayTec and white light, I have to increase the shutter to 1/3000.

If I could capture plates with IR, I would much prefer that route as it isn't as obvious.

 

[actran]

BTW, I would love to capture in color like Parley's image. In addition to plate #, we have the vehicle make/model and possibly color, it's a game changer.

@wittaj I think you should just light up your neighborhood like @CanCuba

 

[wittaj]

BTW, I would love to capture in color like your last image. We can make out the vehicle make/model and possibly color.

To be clear, that last image is from @Parley.

If you have street lights, the 54IR-Z4E with the new S3 chip is a game changer and you might be able to get plates in color.

Prior to the new S3 chip, @Parley was running the previous camera and had to add supplemental infrared to get plates and now he can get them in color with no additional lighting needed. Here was his old setup with two IR illuminators now not needed.

 

[richardgohth]

For those that are from states with stamped/raised plates, IR will still be the better choice due to the reflective property of the plates. Or if you can get the camera close enough to the street you can get the printed plates with infrared. But once you add distance and angle, the 3M printed plates get harder to capture.

But for many of us, circumstances and technology have changed.

When this is the kind of plate we get with the 3M printed plates and infrared, you either accept you won't get as many plates or figure out how to do it color:

View attachment 189422

To be clear, you still have to run fast shutters to capture plates in color. And most do not have the available light. Look how dark my image is except for the plate.

And some don't want a flashing white light emitting from their house every time a car goes by either LOL.

And someone like @Parley has shown in this thread that the new sensor technology, coupled with his available white light, allows him to capture plates in color.

But look at the available white light he has compared to mine where you still only basically see the plate (or a white vehicle barely).

View attachment 189424

And yes, my first attempts did wash out the plate and it was all white. Fortunately the RayTec allows you to adjust the power, so I dropped it down along with increasing the shutter speed.

With the stamped plates and IR, I had to run a 1/2000 shutter due to the reflective properties of the plate washing out the plate with a slower shutter.

With the printed plates and IR, I had to slow the shutter to 1/1000 because the plates were not as reflective. But much slower than that and they are a blur.

With the RayTec and white light, I have to increase the shutter to 1/3000.

If I could capture plates with IR, I would much prefer that route as it isn't as obvious.

we use a gige camera with illuminator synchronised to the shutter and exposure bracketting to expose for both retro and non retroreflective please. One camera and one illuminaotr does the trick.

Neural networks help identify license plates for traffic control

Combining off-the-shelf cameras to a PC running neural network software allows Singapore authorities to perform traffic monitoring and enforcement in an intelligent transportation...

www.vision-systems.com

 

[wittaj]

we use a gige camera with illuminator synchronised to the shutter and exposure bracketting to expose for both retro and non retroreflective please. One camera and one illuminaotr does the trick.

Neural networks help identify license plates for traffic control

Combining off-the-shelf cameras to a PC running neural network software allows Singapore authorities to perform traffic monitoring and enforcement in an intelligent transportation...

www.vision-systems.com

That is awesome. How does the synchronized light look to someone looking at it?

Do you have specs, link to that camera?

 

[richardgohth]

That is awesome. How does the synchronized light look to someone looking at it?

blinking, its NIR so looks reddish, not bright.

Do you have specs, link to that camera?

acA1920-40gm | Basler AG

You'll find the latest and most important information about the Basler acA1920-40gm with a Sony IMX249 CMOS sensor, 2.3 MP of resolution and 42 frames per second here.

www.baslerweb.com

 

[CaptainCrunch]

RayTec has a different approach and sells units with interchangeable filters that will allow you to get 10 degree, 35, or 60 degree standard with the purchase, with optional ones for 80 and 120 degrees.

So I went with the Raytec because it was cheaper and had more flexibility for another use if it didn't work out.

WOW - this thing is a light cannon. Like a tug boat light.

It sounds like this light blinks like the flash on a red light camera. Is that right?

 

[EMPIRETECANDY]

Though @wittaj always lost in the lottery, but camera tech skills is increasing too fast and be an expert now for the LPR

 

[wittaj]

It sounds like this light blinks like the flash on a red light camera. Is that right?

If you set it up that way and have the field of view that it can work in. Mine is a tough angle so the actual flash option using the camera output wires missed the car. But if someone had a more straight on angle where the car is in the field of view for my than 0.5 seconds, the flash would work really well.

Mine is on anywhere from 0.2 seconds to a few seconds depending on the speed of the vehicle. Some of them are simply a flash.

 

[johnfitz]

View attachment 189427

WAF?

 

[Flintstone61]

WTG @wittaj
Glad you figured out something for LPR......My buddies work had somebody beat in his Side Door to his leased office space, and take all the laptops from the cubicles.....and he got faces inside but no plates....

 

[97JeepXJ]

View attachment 189427

WAF?

It’s up to you to decide who wears the pants and whether or not you’re allowed to install a camera, or 7, on the front of your house

 

[wittaj]

Caught one with this setup with a plate in the back window. My LPR camera didn't even see it.

 

[MikeLud1]

Caught one with this setup with a plate in the back window. My LPR camera didn't even see it.

View attachment 191106

The reason the LPR camera did not pick it up is because the license-plate model did not find the plate so it can run the OCR on the plate. The OCR almost reads it correctly. The next release v3.0.4 will have the option to save license-plate model training data so images like this can be added to the training dataset. With this option users can send me the saved training data and I will add the images to the dataset and retrain to the model.

 

[wittaj]

The reason the LPR camera did not pick it up is because the license-plate model did not find the plate so it can run the OCR on the plate. The OCR almost reads it correctly. The next release v3.0.4 will have the option to save license-plate model training data so images like this can be added to the training dataset. With this option users can send me the saved training data and I will add the images to the dataset and retrain to the model.

View attachment 191111
View attachment 191112

I didn't mean your module. Two different cameras.

I mean my LPR Z12E camera running infrared didn't see the plate thru the glass.