Penny Wise, But Pound Foolish: Take Care When You Buy LPR
License Plate Recognition (LPR) has become extremely popular among parking owners and operators. LPR is an essential element of frictionless parking, and it can dramatically improve operations and decrease costs. And by providing data about individual parkers and when and how often they park in a particular facility, the technology provides invaluable information that can be used to run a garage or parking lot more efficiently, and make better long-term planning decisions.
While CCTV and LPR both utilize video cameras, the similarities
One way that owners and operators sometimes hope to minimize their investment is to re-use existing cameras, reprogramming them to provide LPR services. It’s easy to see the appeal of repurposing cameras that are already providing security to also handle revenue control and inventory management.
Just Say No
While CCTV and LPR both utilize video cameras, the similarities end there. The technological specs and capabilities of the two types of cameras are so dissimilar they really can’t be compared.
Or as Sagy Amit of Red LPR says, “It’s a horrible idea that will cause more damage than good. Every vehicle has a dollar sign on top of it and if the camera isn’t accurate or if it can’t process data quickly enough to permit quick entry, the owner is losing money every day.”
The gist of the issue is that CCTV and LPR cameras are different types of technology. CCTV was developed as a security tool and it’s typically used in parking facilities to record activity in parking areas, elevator towers, and lobbies. The cameras themselves aren’t overly sophisticated because they merely need to record the scene.
LPR, on the other hand, is highly specialized equipment that must read license plates and associate those plates with a driver or transaction. This is particularly complicated in the United States because of the great variety of license plates from state to state—and within states, for that matter. Texas and Virginia offer over 300 license plate design choices each.
The first factor, and perhaps the most elemental, is positioning. LPR cameras must be positioned to capture the rear license plate at entry and exit gates. That means locating cameras at gates and aiming them precisely to capture plates, or using mobile LPR units that drive throughout parking facilities to record who is parked in the garage or lot. CCTV cameras, on the other hand, tend to be placed high on walls to capture more of the garage. Even cameras that are aimed at entrances and exits are generally located too high to accurately capture license plates.
“Many states don’t require front plates, so LPR needs to focus on rear plates,” said Walker Consultants’ Geoffrey Posluszny. “You have a trigger loop at gates that activates the system when a car drives onto the loop and records the image of the plate. When you have a standard loop combined with a high speed detector the system can work seamlessly with frictionless parking.”
Seeing the Light
The second factor is the camera’s light sensitivity. When lighting conditions aren’t optimal, older CCTV cameras tend to have trouble reading plates.
“In the end, the resolution and the light conditions need to be there,” according to Selim Esen, CEO and CTO of AVPM. “When lighting conditions aren’t optimal, it’s a challenge to be able to read both reflective and non-reflective plates. That’s why you’ll often see two cameras at entrances and exits, one standard plate and one with infrared capabilities.”
Red LPR’s Sagy Amit thinks this is a key point.
“Most security cameras don’t have the correct infrared technology,” said Amit. “Specific IR spectrums are used for different plates and from state to state, and traditional security cameras just don’t have the right technology when it comes to lighting.”
The System’s Brains
The final factor is the system’s brains. What technology is being used to read the video and translate the feed? Not all CCTV cameras support duel stream, but you need to stream the information that’s being captured to software, and then onto the video management system. If you can’t do that you need to do a post-stream, which is a much more complicated process that’s not always compatible with parking gate systems. Often, CCTV cameras aren’t able to handle the complex processes required to collect the data and then send it to the video management suite to operate the parking system.
Posluszny adds that ultimately the perceived cost savings of repurposing cameras just aren’t there. “As LPR has gotten more popular, the cost of the cameras and LPR systems have come down. At the same time, the technology has improved, with read rates and accuracy improving dramatically. In some parts of the country I’d even say that it’s standard to install LPR in parking facilities.”
Learn more about LPR at PIE 2020. The LPR panel addresses these and other challenges on Monday, March 23 at 9:10 AM.
Kristin Phillips is a technology writer. She can be reached at firstname.lastname@example.org