LPR CAMERA SOLUTIONS
LPR, or License Plate Recognition, surveillance technology is currently a hot topic in the CCTV industry. Not only do you need cameras (hardware) with enough power and features to see the license plate, you need the recorder and/or analytic software to store the license plate information until it is needed.
We hope this breakdown will help you make an educated decision on which solutions is best for you. The solutions can range from under one hundred dollars to over one thousand dollars so being educated is key to making the right decision and being able to capture the results you expect. To simplify this document all that we talk going forward will be based on HD cameras of 1080P and or above. Recording Resolutions under 1080P make it that much more difficult to capture an image with enough quality to read a license plate, tag, or characters on a vehicle.
WHAT IS LPR?
Definition: LPR (License Plate Recognition) also known as Character Recognition
Optiview breaks "LPR" down into three categories.
Locations: Gated Entrance, Parking Garage, Corralled (confined) Entrances
A perfect environment for License Plate Recognition consists of good lighting, slower traffic, and being able to mount the camera within 15-25’ of the vehicle. This set-up could easily put you into one of Optiview’s entry level solutions. Since the vehicles are both moving slower and located closer to where the camera is mounted we don’t have to worry as much about specific technical details such as shutter speeds of the cameras or high intensity LED’s for long range infrared (night vision). If the jobsite has ample lighting we expect the camera to stay in full color. In the case that it does get dark, IR (infrared) is required for night vision.
- Are the vehicles traveling at speeds under 25mph
- Are you within 15-25 feet of the license plate
- Are you at a less than 45° angle from the license plate from where the camera is mounted? This is important that we are receiving the infrared reflection from the license plate and that it’s not reflecting elsewhere but feeding back to the camera.
If you answered YES to the above three questions your most basic of DVR’s may be able to handle this workload and complete your task of retaining images of license plates. We recommend no less than 15fps (frames per second, also known as pictures per second).
Locations: Faster moving traffic or multi-lane
In this environment we need a camera that can perform with a higher shutter speed that can be adjusted. We will also need a camera with a higher intensity LED’s for higher quality night vision; this will give us a larger amount of feedback from the license plate.
Both the higher shutter speed combined with higher intensity LED’s (infrared) allow light to reflect off the license plate and feed the recorder back the negative image of the characters on the tag. LPR specific cameras are typically going to have a much higher shutter speed than standard surveillance cameras which means that we can capture the license plate moving at a higher rate of speed.
Due to the higher technology built into this type and level of camera it is important to make sure your DVR/NVR can perform and keep up with the capture rate (frames per second / pictures per second) and resolution. Your DVR will be the tool you use to play the video back from an event and go frame by frame to read the characters on the license plate. Since this camera will only display in Black and White (showing a negative of the license plate) most customers will install a secondary surveillance camera that records in color and has a wide angle view. That way you have one camera working to retrieve color and description of the vehicle and occupants, and the license plate camera solely for capturing the license plate data.
This approach takes everything that we discussed in Level 2 and adds LPR Software. Optiview’s LPR software can be Linux Based on our AI servers or can be standalone PC based using a third party LPR program. It is always best to discuss your individual needs with an Optiview Account Manager in order to determine which solution is best for you or your customer.
Analytics software for LPR cameras will take the live video image of the license plate and convert it to text that then becomes searchable data. This data can then be set up for future alerts, notification, or actions. Our software will allow you to type in a complete or partial tag number and the software will find any video events that match the query.
Example: You type in Tag # ABC 123 in the search query. A list of video events where Tag # ABC 123 appear. You can now click on any of those events and view the video footage of that event as they passed through.
In most cases our customers will use this search feature to find a general times list of when a vehicle comes and goes. They then use this data to play back video from other cameras in that area to get a more complete view of the situation.
Many systems on the market today are what we call “reactive”. An event occurs, an operator plays back after the event, and backs up the event for record keeping purposes. Notifications allow you to turn your LPR into a pro-active solution.
Example. An ex-employee or ex-student is no longer allowed on property. You can load their license plates into the software and if their license plate number is registered as passing through your LPR camera field of view you receive a notification. This allows you to identify a potential threat as soon as it enters your perimeter.
Another example we hear the LPR being used for is unpaid parking fees. If you have a customer that is past due you no longer have to chase them down. Simply enter their license plate and the next time they visit your parking lot you’ll receive a notification. From that moment you can make the call to the towing company and hold the vehicle for payment.
Our PC based software has the ability to complete tasks for specific tag numbers as well. In one example we can tell it when tag # ABC 123 comes into view we want to open the gate and turn on driveway lights. We can also program the system to open garage doors or, through a series of relays and commands, perform multiple tasks at once.
As you can see Level 3 is our most advanced LPR solution and there are many options that can be added. This level is our most feature rich and most managed solution and is used primarily by our commercial and corporate users. We are also seeing more of our HOA customers move to this solution to better manage who is coming and going from the neighborhood. This has become a powerful tool in today's Neighborhood Watch programs as well.
If you have limited infrastructure where you need to capture license plates visit our Weatherproof DVR’s Tutorial.