What is License Plate Recognition (LPR)?

Video security has advanced significantly in recent years, with new technologies powered by machine learning and advanced artificial intelligence creating new capabilities. One of these features is License Plate Recognition (LPR). This increasingly in-demand feature is able to detect and read license plates to make it much easier for users, or the authorities, to quickly identify any vehicle on the scene.

Use Cases for Automatic License Plate Recognition

The most common license plate recognition (LPR) use case comes during incident investigations, where officials have long struggled to analyze security camera footage for blurry or unreadable license plates. Today’s powerful, more intuitive security cameras can overcome these hurdles. By using AI-driven technology to automatically analyze license plates in real-time, modern devices not only help ensure that numbers will be legible at a distance, at night, or at high speeds.

Modern security cameras are now so accurate that solutions like Verkada’s allows organizations to read, monitor, and search license plates in real time to streamline vehicle investigations, get alerts, even without a complete license plate input. The solution uses Verkada’s edge-based processing and computer vision technology to capture license plate numbers and provide users with a searchable list of plates.

Types of License Plate Recognition

The technology goes by several names: License Plate Recognition (LPR), Automatic Number Plate Recognition, Automated License Plate Readers (ALPR), or Number Plate Recognition (NPR). But no matter the specific terminology, it has become clear that this is a very powerful tool that many users should look to incorporate into their video surveillance system.

Jump to each section to learn more:

• Where are License Plate Reader Cameras Used?

• Use Cases for License Plate Recognition Cameras

• Challenges with existing LPR Camera Solutions

• What to Look for in LPR Camera Systems

• Considerations when Buying an LPR Camera Solution

• FAQs about ANPR, ALPR, and LPR Cameras

Where are License Plate Reader Cameras Used?

Cameras featuring License Plate Recognition (LPR) are a great asset to deploy in a wide range of settings. Really, almost any camera with visibility of an area where vehicles might be present could benefit from having LPR capability. In particular, the following locations represent just a few of the locations that make the most sense for LPR cameras.

• Parking Lots: Parking lots are naturally the top use case for LPR cameras. This is where the bulk of the onsite vehicles will be arriving, parked, and departing from each day, so this is the first location that you will want to monitor.
• Parking Garages: Parking garages check the same boxes as parking lots — a natural site for strategic deployment. This is where you want to make sure you have real-time vigilance over who is coming and going.
• Monitored Entry Stations and Gates: Simply by monitoring points of entry and exit, you can get most of the insight you need into which vehicles have gained access to a location. The logs produced here — featuring times and plate numbers — may be all you need when investigating a typical incident.
• Drive-Throughs: Businesses with drive-throughs should always have surveillance in place in case of an incident, and having license plate recognition ensures you will have more data to analyze or provide to authorities if necessary.
• Toll Gates and Booths: Toll gates and booths are another area that should have video security in place already. Having LPR capability only makes things safer and offers a greater ability to review and understand problems should they arise. State and municipal officials can also use this technology to identify when violations occur and automate the process of rectifying the situation.
• Stop and Go Traffic Areas: Any area with stop-and-go traffic is a prime location that you may want to monitor with LPR-capable devices. Such environments can have dynamic patterns that pose challenges — and having identifiable data may be useful when looking into an event.
• Car Washes: Car washes are naturally one of the many small businesses that can benefit from LPR cameras onsite. Having a better understanding of who is coming and going offers not just enhanced security but could present opportunities in terms of understanding customer frequency and time spent on location.

Use Cases for License Plate Recognition Cameras

• Securing a Restricted Area: Restricted areas demand high security, and in most cases you want to have the most information possible. Today’s technology allows you to know exactly which vehicles are onsite, when they arrive, when they leave, how much time they spend on location, and if they represent any suspicious activity. This is invaluable for security, and modern solutions make it too easy to ignore.
• Monitoring Gate Entrances: Real-time monitoring of gate entrances is naturally very helpful for security, but it also can be beneficial for streamlining access control. An IP license plate camera can identify frequent users, identify new or unauthorized visitors, and work in concert with access control solutions to streamline and add peace of mind to any entry process.
• Resolving Parking Lot Accidents: Traffic accidents don’t just happen on public streets, and you will likely encounter a contentious dispute about a collision in any parking lot you maintain. Having LPR enabled on cameras provides much more clarity and can help make sure any issue is resolved easily and quickly — even in cases where the person at fault left the premises before the incident was known.
• Tracking a Known Suspect’s Vehicle: Plate number recognition can be very useful when there is a specific, potentially dangerous, vehicle to watch for. Whether it’s a disgruntled former employee, a publicly identified threat, or any other potential concern, LPR can notify you if that vehicle is ever detected on location.
• Finding a Vehicle Involved in a Crime: The same applies after the fact for any vehicle that is known to have been involved in a crime. Every organization wants to be on the lookout for threats of this nature — and having this technology can help catch criminals quickly in real-time who otherwise may have never been detected.
• Enforcing Parking Laws, Time Limits, Reserved Spaces: Especially if your parking lot is relatively open and nearby other businesses, members of the public will abuse access and fail to adhere to posted restrictions. Monitoring this can be resource-intensive and wasteful, but it can be automated through LPR cameras that immediately register, for example, when an unauthorized user takes a spot reserved for employees only.

Challenges with existing LPR Camera Solutions

• Software Licensing: While there are options on the market for different LPR cameras, getting the most out of them can be more challenging. In some cases, you may have to purchase a separate software solution that doesn’t integrate well with your wider security or access control platform. This has so far been a large pain point for enterprises that have hardware that works — but little way to get all the benefits in practice.
• Software Compatibility: Software compatibility can be a significant hurdle to implementation. This factor may depend upon the camera system hardware or VMS being used, and if it doesn’t play well together, you will not be able to leverage all the capabilities that you expected to get out of the box.
• Managing Additional Hardware: Most LPR cameras require additional hardware to work properly. You may need an on-premise, LPR-dedicated NVR (network video recorder) that serves as a central hub for device recording storage. This complicates the process, may require integration with local servers, and generally makes the entire installation and operating procedure more laborious, time-consuming, and expensive.
• Unforeseen Costs: LPR camera deployments can include hidden fees and unforeseen costs. In addition to the potential hardware investments beyond the cameras themselves, you may see extra charges based upon the number of cameras operating or the number of lookups per month.
• Limited User Seats: Frustration can occur if your provider limits the number of users permitted to access the system per license. This may not become an issue if you have a small facility or a medium-sized business, but these limits are quickly exhausted in many cases.
• Data Retention: Best practices for storage and data retention times can vary by use case, industry, and individual organizational philosophy. But, as a rule, having the ability to retain the data longer is generally better. Some providers, however, only offer shorter durations by default or charge an extra license fee for longer retention times.

What to Look for in LPR Camera Systems

• Multi-Camera Playback: With Multi-Camera Playback, you can see footage of the License Plate Recognition event on not just the camera that originally captured it but on additional cameras as well. If a car enters a garage and you capture the plate, you would then be able to follow the vehicle as it proceeds down the ramp and turns off in another direction. This allows you to get a more complete picture of where the vehicle went after the initial capture.
• Searchability: Recognizing and storing plate numbers in a database is quite useful, but this utility becomes limited if it is not easy to search for what you need. You want to make sure the database is easily searchable by date and time as well as license plate number. Chances are, you will be looking for something quite specific if an incident occurs, and you don’t want to waste time bogged down in an unwieldy wild goose chase.
• Fuzzy Matching: Older systems have traditionally struggled to read plates well and can fail to return results when even a small portion of the image is hard to read. Modern options are much smarter and can overcome display challenges with features such as “fuzzy matching” or “fuzzy search.” This allows you to still return the correct plate number if, for example, single character registers incorrectly. This way, you won’t be thrown off when the number 0 reads as the letter O or an S is confused for a 5.
• Exportable Logs: A license plate security camera that offers exportable logs makes everything much easier when it comes to aggregating and analyzing data. Simply having the ability to download captured plates as a CSV file means that this data will be much easier to search or use in a variety of applications that may be included in a wider enterprise security or access control system.
• API Integration: The data acquired through a license plate reader CCTV camera can be valuable to customers who want to integrate this data into other platforms. This can make the entire experience much more powerful, so it pays to look for a solution that allows programs to export LPR data into other databases. Some applications that can be used with LPR API include the ability to trigger a parking lot gate to open based on LPR readings, for example — greatly expanding your control.
• Zoom or Bullet Cameras: In most contexts, a zoom bullet camera will offer the greatest capability and most versatile performance. Its ability to zoom in on cars can prove very valuable for reading plates accurately and reliably, but in some cases a separate camera may be useful as well to capture contextual evidence. Often, this determination will come down to the nature of the space you are looking to monitor.

Considerations when Buying an LPR Camera Solution

• Angle, Distance, and Installation Location: Deployment strategy is a key concern for any surveillance hardware, and this consideration is even more true when it comes to LPR-capable cameras. The angle and distance from the installation to the areas where vehicles will be located most often is something that you need to get right. For the best results, an LPR camera should be mounted in the direct field of view of the vehicle that you want to identify, and this may require multiple devices depending upon the size of the area to cover and how dynamic the environment is.
• Price and Budget: All enterprises want to keep costs low and need to work within their budget. But it is important to weigh total cost of ownership (TCO) and overall value that the system can provide. Particularly if you have a single small parking lot or area to monitor for vehicles, adding an LPR camera to an overall system can add a very useful feature to the arsenal.
• Data Retention and Storage: License plate data may not take up a lot of space by itself above the typical requirements for an IP camera, but you need to have a retention method that is reliable and secure. Cloud-based, or hybrid cloud, solutions can offer all the space you need, while onboard storage may have some benefits as well in terms of access or connectivity.
• Durability: Because LPR cameras are generally mounted in open space areas — rather than inside protected, climate-controlled facilities — they need to be able to withstand a variety of weather conditions. While different regions may require different standards, it is usually a good idea to go with something that has a water/dust-proof rating of IP67 or higher.
• Vandal Resistance: With any investment, you want protection, and one beneficial feature for any number plate recognition camera is vandal resistance. This can go by various names (vandal-resistant, vandal-proof, impact-resistant, or tamper-proof which signifies protection against 20 joules of impact). But whenever possible you want to look for something that is rugged and difficult to tamper with. Top options also come with tamper alerts or notifications that will automatically inform users in real-time if they are damaged.
• Additional Hardware: With a license plate recognition camera in place, you will have a great new resource. But will you also need additional devices to capture the larger landscape around your facility? Is there other contextual information that will need to be captured on location by other cameras?
• Maintenance: Given the location of the typical CCTV license plate camera, maintenance will be required from time to time. A lens facing the elements may need to be refocused occasionally, for example, or accumulate dust and dirt. This will need to be addressed along with fixing other external issues such as spider webs or even birds nests.
• Power and Connectivity: Like most cameras, LPR solutions can come with various power and connectivity solutions. It will be important to consider whether cabling/wiring options will be feasible in the expected location or if wireless options, using WiFi connections, for example, are more suitable. How will you connect the camera to best ensure it remains online and powered up?

FAQs about ANPR, ALPR, and LPR Cameras

What are some other acronyms for LPR cameras?

There are various acronyms that can be used to refer to a number plate recognition camera or a license plate reader camera. There may be differences in the underlying technology and capability as well as differences depending upon the preferred terminology of the provider. Because of this, they may not actually be interchangeable, but the following are some of acronyms commonly used to describe a CCTV camera with license plate recognition:

• LPR Camera: License Plate Recognition Camera
• ANPR Camera: Automatic Number Plate Recognition Camera
• ALPR Camera: Automated License Plate Reader Camera
• NPR Camera: Number Plate Recognition Camera

What’s the difference between a License Plate Recognition (LPR) and License Plate Capture (LPC) Camera?

The main difference is that a License Plate Recognition (LPR) camera uses AI to analyze a plate and provide information, whereas License Plate Capture (LPC) just describes a normal security camera that is positioned so that it can record license plates.

What’s the difference between a License Plate Recognition (LPR) and Automatic Number Plate Recognition (ANPR) camera?

In practice, the terms License Plate Recognition (LPR) and Automatic Number Plate Recognition (ANPR) generally mean the same thing. Different providers may characterize their products slightly differently, but you will often see them used interchangeably.

How accurate are LPR cameras?

Modern LPR cameras using advanced AI and machine learning can accurately read license plates over 95% of the time, even with challenges like weather, dirt, distance, and poor lighting. Accuracy depends on factors like camera resolution, angle, distance to vehicles, and illumination.

What kind of camera is best for LPR?

LPR cameras are usually high resolution bullet or PTZ cameras. Bullet cameras provide a fixed view with powerful zoom capabilities to capture plates at a distance. PTZ cameras allow operators to pan, tilt and zoom in on plates as needed.

Do LPR cameras work at night?

Yes, LPR cameras use IR illumination to effectively read plates 24/7, even in low light or total darkness. IR illuminators attached to the camera provide infrared light invisible to the human eye.

Can LPR cameras catch speeding vehicles?

Yes, LPR cameras with radar or paired with speed measurement tools can determine vehicle speeds and automatically flag speeding vehicles. This is useful for traffic enforcement.

Is LPR legal everywhere?

LPR legality depends on local, state and national laws. It is legal in most public places in the US but restrictions apply to persistent tracking of individuals without cause. Users must check relevant privacy regulations.