Poor IR contrast in new Tennessee license plates

[wittaj]

Thanks. I just got to looking and realized that you don't seem to be able to buy an actual 730nm IR blaster . Unfortunately I already have 3 LPR cameras we purchased, about $2k each and didn't realize that they didn't like Tennessee's license plates.

Yes there are, but you need to know if your camera can reliably see it. What camera make/model do you have that you spent $2k on? I would confirm from the manufacturer that it can see 730nm before you fork out quite a bit for these blasters.

Driver Recognition Lighting | VARIO2 | Raytec LED Lighting

730nm Far-Red illuminators for transport applications. Driver recognition lighting and occupancy detection. UK-made and designed.

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[wtimothyholman]

Thank you! The 730nm IR is what I was looking for. I had seen some discussions about the different IR types but wasn't what had been confirmed. Ill check out the 730nm and see about making an investment for those.

But note that your cameras optics must support 730 nm. I learned this the hard way after much experimentation. A camera that operates in 850 nm IR mode won't work with 730 nm illuminators. This includes the standard Dahua -Z12E models that most of us use.

What will work is to use white light, and to keep the camera in daytime mode 24/7. I've just purchased two IPC-B52IR-Z12E-S2 cameras which have much better sensors than earlier versions of the camera, which I'm going to use with some directional soft white light LED illuminators.

Ideally the LED illuminators should strobe on and off synchronously with the opening and closing of the shutter. In this case you'd get plenty of illumination for the sensor, but the light would look dim to the human eye. In practice there's no way to do this with the Dahua camera, as it would require some way to extract that signal from the camera's internal circuitry.

My next option is to try out the IPC-B52IR-Z12E-S2 camera and see if a continuous (but dim) illumination is sufficient for the improved sensors to image the plates. That is my next project.

 

[wittaj]

But note that your cameras optics must support 730 nm. I learned this the hard way after much experimentation. A camera that operates in 850 nm IR mode won't work with 730 nm illuminators. This includes the standard Dahua -Z12E models that most of us use.

What will work is to use white light, and to keep the camera in daytime mode 24/7. I've just purchased two IPC-B52IR-Z12E-S2 cameras which have much better sensors than earlier versions of the camera, which I'm going to use with some directional soft white light LED illuminators.

Ideally the LED illuminators should strobe on and off synchronously with the opening and closing of the shutter. In this case you'd get plenty of illumination for the sensor, but the light would look dim to the human eye. In practice there's no way to do this with the Dahua camera, as it would require some way to extract that signal from the camera's internal circuitry.

My next option is to try out the IPC-B52IR-Z12E-S2 camera and see if a continuous (but dim) illumination is sufficient for the improved sensors to image the plates. That is my next project.

Or set it up with a spotter cam to hit a focused white beam for a split second to capture the plate

Gotcha 3M Printed Plates at Night - LPR

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...

ipcamtalk.com

 

[inforlonghaul]

Yes there are, but you need to know if your camera can reliably see it. What camera make/model do you have that you spent $2k on? I would confirm from the manufacturer that it can see 730nm before you fork out quite a bit for these blasters.

Driver Recognition Lighting | VARIO2 | Raytec LED Lighting

730nm Far-Red illuminators for transport applications. Driver recognition lighting and occupancy detection. UK-made and designed.

www.raytecled.com

We purchased an ANPR camera from Digital Watchdog - DWC-XSBA05MiL. But yall make a good point about the lens needing to be able to 'see' it. I saw where Flock had made comments that they some how 'trained' their cameras to be able to identify the new plates from Tennessee. I wonder if this is something the manufacturer of that DW camera could do in an update. I obviously doubt it but it would definitely be interesting.

 

[wtimothyholman]

Or set it up with a spotter cam to hit a focused white beam for a split second to capture the plate

Gotcha 3M Printed Plates at Night - LPR

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...

ipcamtalk.com

I've considered that, but a very bright light that flashes for a couple of seconds can still be problematic for passing drivers. I'd hoping for something that has the same color temperature as a porch light, but no brighter to the human eye.

 

[wittaj]

We purchased an ANPR camera from Digital Watchdog - DWC-XSBA05MiL. But yall make a good point about the lens needing to be able to 'see' it. I saw where Flock had made comments that they some how 'trained' their cameras to be able to identify the new plates from Tennessee. I wonder if this is something the manufacturer of that DW camera could do in an update. I obviously doubt it but it would definitely be interesting.

Certainly not helping is that camera is not on an ideal MP/sensor ratio - it is 5MP on the 1/2.8" sensor.

So it needs almost 2.5 times the light of the Z12E that is 2MP on the same 1/2.8" sensor size (quite possible same sensor).

Talking to my law enforcement friends, they say Flock isn't that good with their adjustments and my B/W LPR camera does better than the Flock.

 

[wtimothyholman]

We purchased an ANPR camera from Digital Watchdog - DWC-XSBA05MiL. But yall make a good point about the lens needing to be able to 'see' it. I saw where Flock had made comments that they some how 'trained' their cameras to be able to identify the new plates from Tennessee. I wonder if this is something the manufacturer of that DW camera could do in an update. I obviously doubt it but it would definitely be interesting.

I've been told by a local cop who is very familiar with Flock cameras that they are transitioning to 730 nm illuminators in their latest models. I haven't been able to confirm that, however. Flock, like Rekor, has done what they can in software to improve plate reads, but you can't fight physics. There simply isn't enough contrast in the new plates for consistent reads at 850 nm. In particular, any precipitation in the air makes them unreadable.

 

[inforlonghaul]

Certainly not helping is that camera is not on an ideal MP/sensor ratio - it is 5MP on the 1/2.8" sensor.

So it needs almost 2.5 times the light of the Z12E that is 2MP on the same 1/2.8" sensor size (quite possible same sensor).

Talking to my law enforcement friends, they say Flock isn't that good with their adjustments and my B/W LPR camera does better than the Flock.

We can bump the resolution down to 1080p. Would that make any difference as far as what you're saying or is it still because of the internal lens itself being a 5mp with the 1/2.8" sensor still the issue.

 

[wittaj]

I've been told by a local cop who is very familiar with Flock cameras that they are transitioning to 730 nm illuminators in their latest models. I haven't been able to confirm that, however. Flock, like Rekor, has done what they can in software to improve plate reads, but you can't fight physics. There simply isn't enough contrast in the new plates for consistent reads at 850 nm. In particular, any precipitation in the air makes them unreadable.

That would certainly help, but the ones near me do not have 730 as they are way more noticeable than the 850.

I suspect more Flock cameras will be damaged as they will become more noticeable at night and those up to no-good will take them out. I know they are there and I don't see them at night. With 730 I will.

 

[wittaj]

We can bump the resolution down to 1080p. Would that make any difference as far as what you're saying or is it still because of the internal lens itself being a 5mp with the 1/2.8" sensor still the issue.

Bumping the resolution down would be useless because it still has the 5MP "screen" that it is preventing more light from getting thru.

 

[wittaj]

I've considered that, but a very bright light that flashes for a couple of seconds can still be problematic for passing drivers. I'd hoping for something that has the same color temperature as a porch light, but no brighter to the human eye.

True it certainly depends on the amount of traffic and the angle. Mine is up high so people passing by don't notice it. I know it is there and I go by and I am like "did it come on?"

RayTec and Axton do sell a pulsed version that would make it way less noticeable, but I haven't been willing to cough up the cash for that.

Pulsar 100R, Pulsed IR or White Light camera synced pulsed Light

Camera Synced Pulsed LED Light, for LPR, MV Cameras - IR, Infra-Red ,White LED Lights, Built-In Pulse Generator | LIFETIME WARRANTY | USA Mfr. AXTON

axtontech.com

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PULSESTAR VTS20 High Intensity Pulsed Lighting for transport applications, such as ANPR and rail. Designed and manufactured in the UK.

www.raytecled.com

 

[wittaj]

@inforlonghaul - how far away are the plates from the camera?

Someone in this thread I showed the testing I did where if you can pump enough IR light to the plate, you stand a somewhat chance of getting them. But it has to be a Raytec or Axton that can pump out a concentrated 10degree beam to really focus it on a tight spot.

But ideally you want to get the camera as close as you can.

 

[wtimothyholman]

That would certainly help, but the ones near me do not have 730 as they are way more noticeable than the 850.

I suspect more Flock cameras will be damaged as they will become more noticeable at night.

They could reduce the visibility by strobing the 730 nm LEDs synchronously with the shutter. A 30 Hz to 60 Hz strobe is not difficult with LEDs. Yet it seems that manufacturers insist on constant illumination, which wastes power and increases apparent brightness to passing drivers in vehicles.

That's the frustrating thing about the camera market. Everyone depends on Chinese manufacturers to design the electronics and optics, while they focus on the software. It never seems to occur to anyone to ask the Chinese engineers to create something different in hardware.

 

[inforlonghaul]

Here's some examples of what we've been getting trying to tinker with different settings with varying degrees off success. As far as doing it in color though, success is very spotty and the majority of the time at night our ANPR does not get a read on the plate even though we can almost always manually read it ourselves. But a lot of times the plate comes in blurry and can't be read anyway so it doesn't make much difference between having IR on or doing it in color.

 

[inforlonghaul]

@inforlonghaul - how far away are the plates from the camera?

Someone in this thread I showed the testing I did where if you can pump enough IR light to the plate, you stand a somewhat chance of getting them. But it has to be a Raytec or Axton that can pump out a concentrated 10degree beam to really focus it on a tight spot.

But ideally you want to get the camera as close as you can.

I attached some pictures in my previous post, but I would say the plates are about 120ft from the camera itself. Not ideal by any means I know, but unfortunately was limited in where we could put them, but I also know that unfortunately can tie hands on trying to get the IR issue effectively resolved. Double-edged sword.

 

[wittaj]

Here's some examples of what we've been getting trying to tinker with different settings with varying degrees off success. As far as doing it in color though, success is very spotty and the majority of the time at night our ANPR does not get a read on the plate even though we can almost always manually read it ourselves. But a lot of times the plate comes in blurry and can't be read anyway so it doesn't make much difference between having IR on or doing it in color.

Yeah you are dealing with a lot of noise there, no doubt because of the 5MP on a sensor designed for 2MP.

You can probably get the color ones on cars with working plate lights.

Those are not terrible, but you certainly hate to waste the ANPR capabilities of the camera because you paid a lot of money for that capability.

Yeah 120 feet on a 50mm focal length is pushing the boundaries. Are you full zoom on those images?

 

[inforlonghaul]

Yeah you are dealing with a lot of noise there, no doubt because of the 5MP on a sensor designed for 2MP.

You can probably get the color ones on cars with working plate lights.

Those are not terrible, but you certainly hate to waste the ANPR capabilities of the camera because you paid a lot of money for that capability.

Yeah 120 feet on a 50mm focal length is pushing the boundaries. Are you full zoom on those images?

Yes, I would say the camera is at almost max zoom. I didn't want to capture plates at too much of an angle, so I tried to straighten it out more down the roadway so it could have a more straight-line shot.

 

[wittaj]

It's a great angle. I would be half tempted to try the 10 degree IR blaster and see if you can hit enough to make it readable.

Or consider the pulsed white light?

 

[inforlonghaul]

It's a great angle. I would be half tempted to try the 10 degree IR blaster and see if you can hit enough to make it readable.

Or consider the pulsed white light?

I'm not sure about the pulsed white light or how I'd be able to make that work. Not sure I'm quite that savvy. Not be worried about blinding somebody driving down the road?

The IR blaster is definately something I could check into and see about getting one to try. Do you think more IR would be better and not wash it out?

 

[wittaj]

The idea of the pulsed light is it greatly reduces the amount of light our eyes can see. It may look like a 50 watt light bulb.

It would certainly be less intense than someone driving past you with their headlights on. And if you can put it on 2nd floor and have it only activate for the rear of the vehicle, the blinding risk is even less and they would probably never see it.

If the camera has an alarm out wire you simply connect the light to it and in the camera GUI tell it to activate alarm I/O when triggered.

If the IR is too much you deal with the washout with a faster shutter. But it will take some trial and error and the ANPR may not be able to read it even if you can.