Recently, I installed our new 4mp Viewtron LPR camera at my house to test the automatic license plate reader software at an angle and distance much greater than CCTV Camera Pros normally recommends. We have been supplying our 2mp Viewtron LPR camera for four years and it has been a tremendous success. However, almost all of our LPR camera system customers have been businesses and government installations.
Home LPR camera sales have mostly been limited to large residential properties that have long driveways and/or gated access points. This is because of the strict installation requirements for LPR cameras. Specifically, the minimal horizontal and vertical angle that is required for license plate recognition software to work properly if very difficult to achieve when mounting to a house. The team at CCTV Camera Pros has talked many homeowners out of buying LPR cameras because we knew it would not work well on a typical home installation.
The new 4mp LPR camera model looks the same the 2mp model, except that it has a larger focal. It has a 8 to 32mm motorized varifocal lens, and is also twice the resolution at 4mp vs 2mp. I thought that maybe license plate capture may be somewhat possible when installed on the front of my house if we pointed the camera as far down the street as possible and zoom the lens all the way in. This would create the most minimal angle as possible within the recommended maximum license plate detection distance of 80 feet. My original idea for the above video was to explain why LPR cameras DO NOT work well when installed on the front of a house. However, the results using the new Viewtron LPR-IP4 were very surprising for both daytime and night time license plate capture.
This is where I mounted the LPR camera on my house. Normally, I have a Viewtron 4K AI camera installed in that spot to monitor my driveway. The 9 foot 4 inch installation height is MUCH higher that we we recommend for LPR. We typically recommend that LPR camera are installed as level to license plate height as possible.
My house is set back 35 feet from the street. This is MUCH farther away than we recommend for LPR camera installation. We usually tell customers that they need a pole as close to the street as possible.
Here is a close-up of the installation so that you can see the angle I used when focusing the camera on the LPR detection zone.
Here is a picture that I took from where the LPR camera is installed, pointing away from the house towards the LPR detection zone. I also measured the distance from the camera to where I created the plate detection zone in the LPR software. It is 110 feet away from the camera is installed. As I previously mentioned, this LPR camera has a recommended max LPR range of 80 feet.
Here is the LPR software setup screen on the Viewtron NVR that the LPR camera is connected to. The large green rectangle on the screen defines the license plate detection zone. The two smaller rectangles define the size range of the license plates that will be passing through the detection zone.
After I setup the license plate recognition zone on the Viewtron NVR, I left the LPR detection recording on for a few days. The results were amazing! I was expecting to be able to identify some plates by manually reviewing the recorded video surveillance video on the NVR. I was very surprised to find that the AI software was not only detecting license plates, it was also automatically recognizing the license plate numbers and letters. This is known as automatic license plate recognition.
The above screenshot is the Intelligent Analytics search screen on the NVR. It lets you search for all of the license plate recognition events.
Daytime License Plate Recognition
Here is a screenshot of one of the license plate recognition events from daytime recording. You can click on the above image to open a higher resolution screenshot so that you can see the license plate better.
Here is a close-up view of the day time license plate capture.
Here is a screenshot of the night time license plate recording. Please also notice the timeline on the right hand side of the video playback screen. All of the license plate recognition events are notated with a light blue color so that you can easily jump to other LPR events on the video playback screen.
Here is a zoomed in view of the night time LPR.
License Plate Capture vs License Plate Reader
After testing the Viewtron LPR-IP4 at my house for a week, I made the above video to share additional results and my latest thoughts. In case you are not familiar with the difference between a license plate capture camera (LPC) and a license plate reader camera (same thing as license plate recognition), here are some definitions.
- LPC Camera – A license plate capture camera is specialized security camera that is capable of capturing video surveillance footage of license plates on moving vehicles where the recording is clear enough for a human to identify the plate numbers and letters.
- LPR Camera – An automatic license plate recognition camera, or license plate reader camera, is specialized security camera that is capable if capturing surveillance video footage of license plates on moving vehicles and also has ALPR software built into it that can identify the existence of a license plate and automatically recognize the numbers and letters on the plate.
The Viewtron LPR-IP4 is an LPR camera, so it also performs license plate capture. After testing at the extreme angle and distance of the installation on my house, I noticed that the LPR-IP4 was not automatically recognizing all license plates that passed by. But it was recording all of the license plates clear enough for me to read when I received the recorded video surveillance footage. So, I setup a second IP camera on the front of my house to detect all of the cars that passed by.
The Viewtron IP-A8BL IP camera that I have mounted on the other side of my garage is an AI security camera. This means that it supports the ability to when humans and vehicles intrude in areas that you can define. When the camera detects a car, it can trigger video recording on any one or more camera’s that are connected to the same NVR. When you trigger AI event video recording, the event is bookmarked on the video playback timeline of all the camera it triggered video recording on.
Here is a screenshot of the video playback screen on the Viewtron NVR that the LPR camera and AI security camera are connected to. This is the LPR camera. You can see the vehicle detection events annotated on the video player timeline in light blue. You can jump to each of those events by clicking on them with the mouse. This allows me to quickly go back and manually review any license plate capture events, when the LPR camera does not automatically recognize a license plate.
Viewtron IP Camera NVR
Please note that the video demo at the top of this page and all of the above screenshots were captured on the Viewtron IP camera NVR that the LPR camera is connected to. All Viewtron NVRs support Viewtron LPR camera functions and AI camera functions.
LPR Event Playback from Mobile App
Viewtron DVRs and NVRs support the ability to remotely monitor your security camera system from the mobile app for iPhone and Android. On the recorded video playback screen in the app, license plate detection events are notated in green on the video timeline. This makes it very simple to locate all of the LPR events remotely from the mobile app.
Night Time Front Plate LPR
Capturing license plates on the front of vehicles is more difficult that rear mounted plates. This is because of the headlight glare that LPR cameras must compensate for. I was really amazed to see the Viewtron LPR-IP4 accurately recognizing plates on the front of vehicles at this extreme angle and distance. The front of that car is 130 feet away from the LPR camera! Please click on any of the above images for a larger view that you ca digitally zoom in on.
Here is a close-up of the front license plate recognition at night. You can see that the Viewtron LPR camera does a great job of compensating for the headlight glare.
Summary and Thoughts
When I installed the LPR-IP4 at my house, my intention was to show customers that license plate recognition is not reliable when installed on the front of a home. Honestly, I thought that the chances were pretty good that it would not work at all. The actual results of this testing have me and the team at CCTV Camera Pros rethinking our installation recommendations for our new Viewtron LPR camera model. That being said, it is important to note that the road in front of my house does have a curve to it. It is not exactly perpendicular to the road as most houses are. I believe this is one of the factors that gave my tests such great success.
Also, it looks like capturing license plates on the front of vehicles actually works better when you have some horizontal and / or vertical angle to the license plate detection zone. This avoids vehicle headlights blaring straight into the camera lens and causing the camera to switch out of night time infrared mode. Going forward, we will be sending customers to this article in addition to our LPR installation guide to show that LPR camera installation can be successful even at less than ideal installation angles and distances.
Viewtron LPR Camera Video Library
Here is a transcript of the video at the top of this page.
Hi, everyone. Mike from CCTV Camera Pros here. In this video I’m going to test one of our Viewtron LPR cameras by mounting it at my house and setting the license plate recognition zone at an extreme angle that I wouldn’t normally recommend anyone use.
We’ve been selling our Viewtron license plate recognition cameras now for many years, and it’s been tremendously successful. But one of the things with LPR cameras is there’s some strict installation requirements where the camera should be mounted as low to the ground, even with the license plate detection zone as possible, and then not too much of a vertical or horizontal angle from the LPR detection zone. Well, honestly, we have a lot of homeowners that contact us that want to install an LPR camera on their house similar to how I temporarily installed that one behind me. And me and the team have been telling people for years, “No, you can’t do this because it’s way too much of an angle. Houses are set back too far from the road. You’re going to have to mount it too high and it just doesn’t work,” which has been the case up until now. Well, our new LPR IP4 model, that’s a four megapixel LPR camera, has a bigger lens than our existing LPR IP7. It’s an 8 to 32 millimeter lens, which lets you zoom in a lot more.
Anyways, I set out to do this video to show people actually what not to do and how LPR does not work well when installed on a house, but I was really surprised it worked great. So a couple things. That camera is mounted nine feet, four inches off the ground, and my house is set back exactly 30 feet from the road in front of it. Now, my house is not exactly perpendicular. This road curves around a little bit. You could see the curve there. So I’m not exactly perpendicular to the road like most houses are, but the angle is not that great either. So what I did was I angled the camera as much as possible down the street to minimize the LPR detection zone angle as much as possible. So I angled it as far as I could and then zoomed into a reasonable license plate detection zone. This license plate detection zone happens to be 110 feet away from where the camera is mounted, which is outside the detection zone that we typically recommend. So another variable that I didn’t think would bode well for license plate recognition.
Anyways, I’m going to go upstairs on the recorder and play back some license plate recognition events for you both for daytime LPR and nighttime LPR. And I think, like myself, you’re going to be very surprised.
Here’s the live view on the Viewtron NVR that the LPR camera and my other IP cameras are connected to. This is the Viewtron LPR camera right here. I want to search for all the license plate recognition events. I do that by selecting intelligent analytics from this menu on the left. And then on the intelligent analytics screen, I’m going to select vehicle. I’ll leave the date as today. And I only want to search the Viewtron LPR camera for events. So I’ll select that. And then the type of event is plate detection and license plate recognition.
When I’m done, I click on this search button and now it’s querying the database for all the license plate detection and license plate recognition events. So it shows a thumbnail image of the plates that were captured. And then you’ll see down below the number plate recognition. So if I check off one of these events and select playback, that’ll start the video surveillance recording at that moment in time. And I’ll zoom into the license plate here and you could see it’s crystal clear. So when I’m done, I’m going to click exit and I’ll go back to the event search screen again.
I want to pull up event now that was when it was dark out. So I’ll go to very early this morning before the sun was up, and I’ll select one of the nighttime license plate recognition events by checking the box on the thumbnail and then selecting playback again. Went a little too far there, so I’m going to back that up. You could use these video controls down here, obviously, to go in forward and reverse and then speed up the video. So I’ll pause it again and zoom in. You could see that the nighttime license play recognition is even better than the daytime. That is crystal clear.
Another thing I just want to show you is when you have the playback screen open, you can jump to any of the license plate recognition events by using this timeline over here. The license plate recognition events are annotated in that light aqua blue color. So I’ll just pull up one more here and pause it again and zoom in on the plate, and you could see another excellent nighttime license plate recognition event captured right there. When I’m done, I can exit out of the video playback screen down here, and I’ll close that search screen and I’ll back at the live view of the LPR camera, and we’ll go back to that six camera view that we started at. Here’s the live view of my home system.
Guys, I hope this video has been helpful. CCTV Camera Pros has been supplying our Viewtron LPR camera solutions for commercial applications, business owners and governments for many years. And me, James, Carlos, and Greg, we’ve been deterring homeowners from our Viewtron LPR camera and LPR cameras in general because they generally don’t work at extreme angles like the one I just tested here. Well, I think we’re going to have to rethink this a little bit and update our recommendations because this clearly shows that the Viewtron LPR IP4 can work fine when installed on a house like this. Now, I don’t know if it’ll work as well if the road in front of my house didn’t have that little bit of curve. It’s not going to work as well if your house is exactly perpendicular, but at the same time, the curve is not that great, and the license plate detection zone I set up there starts before the road really starts curving a lot.
Anyways, if you want to see additional videos, and I’m going to have more photos of this test that I did on the website, and we have a whole bunch of other videos of our Viewtron LPR system, you can go to www.cctvcamerapros.com/LPR. If you ever want to reach out to me for questions directly, you could email me direct at email@example.com. Thank you for watching.