How license plate recognition works with Milestone

Popular LPR use cases
Organizations across public and private sectors use license plate recognition to automate processes, improve situational awareness and quickly locate vehicles of interest within live or recorded video. Common applications include:

• Traffic management: Used to monitor traffic flow, identify vehicles involved in incidents, and support tolling, congestion management and transportation planning.
• Public safety and investigations: Used in both real-time response and forensic search to identify vehicles of interest, support investigations and improve situational awareness.
• Parking and access control: Used to automate vehicle access, manage parking facilities and streamline the movement of authorized vehicles through secured entry and exit points.

Milestone offers multiple ways to incorporate license plate recognition into your security operations. While all three solutions can identify and search for license plates, they differ in their primary purpose, deployment model and licensing. Use the comparison below to understand where each solution fits before exploring them in more detail.

Now that we have a high-level understanding of license plate recognition with Milestone, let’s dive deeper into XProtect LPR, BriefCam and Arcules individually so you can better understand their capabilities, deployment options and ideal use cases.

These definitions explain some of the terminology used in the comparison table to help you understand how the products differ. Not every feature described below is available in every solution:

• Match lists are predefined lists of license plates that the system monitors. They can be used to trigger automated actions, such as opening a gate for authorized vehicles or generating an alarm when a vehicle on a watchlist is detected.
• Country detection enables the system to identify the country or region associated with a license plate. This is particularly useful in border regions or other locations where vehicles from multiple countries are common.
• Style aliases group different license plate formats or vehicle categories under a common name. This simplifies rule creation by allowing multiple plate styles, such as emergency vehicles or diplomatic vehicles, to be managed using a single policy.

In terms of technical requirements:

• The XProtect LPR extension works with all variants of XProtect as well as all cameras supported by XProtect, providing multi-lane detection with a single camera.
• For any camera to work well, though, you’ll need to go through some calibration steps. 
• The extension supports all countries on this list.   
• Server requirements will depend on 1) the scale of your LPR needs and 2) server components (e.g., CPU and RAM). The extension is fully compatible with dedicated Husky servers. It also works on other servers that meet the LPR spec requirements.
• If you have only one or two LPR cameras for your office building, you can likely run them alongside your core VMS on the same server. For larger projects, however, it’s necessary to have a dedicated LPR server. Some testing indicates that the best quality server can handle up to 80-100 LPR cameras, but your mileage may vary.   

In terms of licensing, three are needed for the LPR extension:  

• The base license, which covers an unrestricted number of LPR servers
• The LPR camera license, charged per camera that you need to run LPR  
• The LPR country module license, which applies to each country, state or region that you need in your analytics (five modules are included in the base license) 

In terms of technical requirements: 

• The text on a license plate should be at least approximately 10 pixels in height for reliable detection. BriefCam ingests video from fixed cameras, with recommended resolutions ranging from CIF up to 4K and typical frame rates of 8–30 fps. 
• Hardware requirements vary based on deployment size and workload. Processing, particularly for real-time analytics, is typically GPU-accelerated and sized according to the number of cameras and the resolution being analyzed. 

BriefCam licensing:

• You don't pay an additional license for LPR; it comes out-of-the-box with BriefCam. 
• That said, your LPR capabilities depend on which BriefCam product edition you have. For example, if you have the Insights edition connected to a VMS, you can receive live alerts based on LPR events, such as the detection of a blacklisted vehicle. Review-only editions, like Investigator, support LPR for forensic search across recorded video but do not enable live response. 

Deployment requirements

• Arcules license plate recognition is supported on compatible Axis cameras running the Axis License Plate Verifier application.
• For Camera-to-Cloud deployments, supported cameras must have at least 2 GB of RAM, run AXIS OS 11.11 or later and include an SD card for edge storage.
• License plate recognition is processed directly on the camera before plate metadata is sent to Arcules for forensic search.
• Camera-to-Cloud and Gateway deployments are supported, depending on the camera model and deployment architecture.

Arcules LPR Licensing

• An Arcules subscription is required for each connected camera.
• Each camera performing license plate recognition requires its own Axis License Plate Verifier license.

Here are examples from our customers who use the XProtect LPR extension: 

• Residential: In Uruguay, a virtual doorman company uses video management and license plate recognition to remotely grant access to visitors and automatically open parking barriers for residents' vehicles.
• Manufacturing: An Italian packaging company integrates license plate recognition into their video management system to control vehicle access while also monitoring production line repairs. 
• Traffic management: In addition to working with local police to resolve traffic cases, the City of Hobart monitors traffic patterns and parking lot occupancy.

And here are a few examples of customers using BriefCam for LPR and beyond: 

• Law enforcement: Through the integrated use of XProtect and BriefCam, the Hartford Police Department has seen a 442% increase in the solvability of shooting cases with video evidence.
• Public safety: The City of Genoa uses XProtect and BriefCam's LPR to review and respond to footage from thousands of security cameras.
• Public safety: In the Tlaxcala, Mexico, authorities use XProtect and BriefCam analytics for license plate recognition and object detection across 800+ cameras, helping reduce cargo thefts by 93% and vehicle thefts by 22.5% while improving investigation speed and emergency response.