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2024 Complete Guide to License Plate Recognition System

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Update time : 2024-01-04 13:56:00

1. What is license plate recognition?

License Plate Recognition (LPR) , also call number plate recognition (NPR), is a technology used for automatically recognizing license plates on vehicles. It works by using optical character recognition (OCR) to detect the alphanumeric characters of a license plate from an image or video, and then match it to a database. This technology is often used in law enforcement, security and surveillance applications, parking lot management, as it can provide real-time information about a vehicle’s whereabouts.
license plate recognition technology

What is license plate recognition parking system? 

License plate recognition (LRP) parking system is an automated parking management system that uses license plate recognition technology to identify vehicles entering and exiting the parking lot.

License plate recognition parking systems are designed to read and recognize license plates of vehicles entering and exiting the parking lot. They utilize advanced optical cameras and intelligent character recognition software to capture and identify license plates. The parking lot system then verifies the license plate information against a database of authorized vehicles and parking preferences. Once the information is verified, parking access is granted or denied to the driver accordingly.

6 components of the license plate recognition parking system

1. Computer

The management computer is mainly used to install the license plate recognition system and the vehicle management system, and it is used to control management and store data. the

2. License plate recognition camera

It can monitor and capture passing vehicles, and transmit the captured images to the system for recognition, so as to achieve the effect of automatic license plate recognition. the

3. Boom barrier

The boom barrier is mainly used to control and manage the entry and exit of vehicles, and the automatic boom barrier is also equipped with other functions, such as anti-smashing function and self-contained display screen. the

4. Loop detector (Radar)

When the loop detector is used in conjunction with boom barrier, it can play the role of preventing smashing cars and automatically closing the boom barrier gate when the vehicle passes by.

5. Electronic display

An electronic display screen is installed at the entrance to display the real-time status of parking spaces and vehicle information such as remaining parking spaces. the

6. Fill light 

The supplementary light not only eliminates the impact of insufficient light on the license plate recognition rate, but also needs to select and match supplementary light equipment with different intensities according to the environment.

How does LPR parking system work?

1. Licensed vehicles:

1) Vehicle entry:

①. The vehicle enters the identification area.
②. The license plate recognition system automatically scans and recognizes the license plate number, and then obtains the vehicle category (non-registered temporary car, VIP car, monthly rental car, credit vehicle, etc.) by searching the database.
③. The display screen shows the validity period of the car (VIP car or monthly rental car) or the balance (point vehicle), and prompts such as welcome.
④, Voice play the recognized license plate, welcome and other prompts.
⑤. Boom barrier rises to allow vehicles to enter, and record the vehicle entry time at the same time. After the vehicle enters, the boom barrier is automatically closed, and the system automatically refreshes the parking space information.

LRP for rental car
The whole process is completed automatically without the intervention of staff. The vehicle is always in motion without stopping.

2) Vehicle departure:

①. The vehicle enters the license plate recognition area.
②. The license plate recognition system automatically recognizes the license plate number, and then obtains the vehicle category by searching the database.
③. The display screen shows the valid period of the car (VIP car or monthly rental car) or balance (stored value car), the amount of charge (temporary car), wishing you a smooth journey and other prompts.
④. Voice play the recognized license plate, I wish you a good journey and other prompts.
⑤. If the car is a registered vehicle (including VIP car, monthly rental car, credit car), the boom barrier will automatically open and release. The computer calls out the captured image of the car when it enters the venue, the admission time and so on.
If it is temporary parking, the vehicle must pay for the parking before leaving.

LRP for temporary car
If it is a temporary vehicle to shop in the mall, there are two situations for payment:
A. Free of charge: when the consumer pays the bill, the cashier enters the designated license plate number on the terminal computer, and the boom barrier is automatically opened when the customer is on the scene, which is valid once;
B. Discount: When the consumer pays the bill, the cashier enters the designated license plate number and fare discount on the terminal computer. Then consumer should pay and leave within a limited time. All records in the system can query statistics and generate reports.
⑥. The vehicle passes through the exit and leaves the parking lot. The system records the time of the vehicle's departure, and the system automatically refreshes the parking space information.

2. Unlicensed vehicles:

Internal monthly subscription for unlicensed vehicles and motorcycles: first pay the fee at the property management center, and the property management will issue an IC card or register a QR code as a voucher for entry and exit;


1. Monthly users:
Directly swipe the IC card or the reserved mobile phone QR code on the multi-function reading head, and at the same time, the entrance camera captures the entrance picture, and the LED display broadcasts the card number or QR code number and welcome message, boom barrier automatically open;
2. Temporary users:
1. IC card: The guard booth security uses a desktop card issuer to swipe the card and hand it over to the temporary user. At the same time, the entrance camera captures the entry picture, the LED display screen broadcasts the card number and welcome message, the boom barrier opens, and the timer starts;
2. Two-dimensional code: Temporary users swipe the two-dimensional code on the mobile phone, this two-dimensional code is used as the admission certificate, and the entrance camera captures the entrance picture at the same time. The LED display will broadcast the two-dimensional code number and welcome message, and the boom barrier will open. Timing begins;


1. Monthly users:
Directly swipe the IC card or the reserved QR code of the mobile phone on the multi-function reading head, and at the same time, the exit camera captures the picture of the appearance, and the LED display will broadcast the card number or QR code number and farewell message, and the boom barrier will automatically Open;
2. Temporary users:
1. IC card: If you take the card to enter the venue, you will hand the card to the security guard at the booth, and the security guard will use the desktop card reader to swipe the card, and at the same time, the exit camera will capture the picture of the exit, and the LED display will broadcast the parking time and payment amount. The security guard opens the boom barrier remotely;
2. QR code: Temporary users swipe the QR code when entering the venue on their mobile phones. At the same time, the exit camera captures the exit picture, and the LED display screen broadcasts the parking duration and payment amount. After payment, the security guard opens the boom barrier remotely.

Where can you buy LPR parking system?

Macrosafe has been focused in R&D of  license plate recongition parking system for over 10 years with more than 8,000 project home and abroad. And Our experts can provide customized LPR parking system solution according to your site environment and project requirements. Please contact us right now or click on the following LRP parking system products for more information:
 automatic number plate recognition  Automatic License Plate Recognition  vehicle license plate recognition camera  car plate recognition

Disadvantages of RFID card parking systems

A RFID card parking system is a method of controlling access to parking lots and garages. This technology utilizes Radio Frequency Identification (RFID) cards to identify authorized users, allowing them to quickly and conveniently enter and exit the parking facility. The card contains an embedded radio frequency transponder which can be read by scanners positioned at entry and exit points. The card is swiped over the scanner which then verifies the cardholder's identity against a central database before granting access.


Smart card is an earlier parking lot management system technology. Vehicles enter the parking lot through self-service or card issuance by staff. Give the parking card to the staff and pay for it when want to leave parking lot. Commonly used parking cards are mainly divided into the following types: IC card, ID card, Bluetooth card, etc.

Today, 90% of parking lots use license plate recognition systems instead of RFID card swiping systems, because it has many shortcomings:

1. Card parking system basically relies on manual opening of the gates for charging vehicles. Not only is the efficiency low, the waiting time is long, it is easy to cause traffic jams, and the labor cost is high.
2. Card parking lot system has a lot of supporting equipment, and the cost is relatively high.
3. Card parking lot system uses cash payment, not only the payment process is cumbersome, but also prone to financial loopholes.
4. It is troublesome to renew the card parking lot system. It needs to be recharged in advance, and it cannot be paid online, so it needs to be processed at a designated place.
5. The card charging method is usually very time-consuming, which can easily cause queuing congestion, and the car owner's experience is very poor.
6. Card parking system is equipped with a lot of supporting equipment, which is often prone to failure and high after-sales costs.
7. Card parking lot system is generally local closed management, and the scalability of functions and data is very poor.
8. The vehicle information data of the Card parking system can only be saved locally, so once the hardware is damaged, the data will be lost and cannot be repaired.


Benefits LRP parking system brings us

The technology that goes into our homes, vehicles and everyday lives continue to evolve over time. We now have the opportunity to add a new layer of convenience and security with the introduction of license plate recognition parking systems (LPR). In this blog post we will explore how befits license plate recognition parking system brings us closer to achieving smarter cities in 2023.

LPR system benefits
1. Improve the automation and intelligence of the parking lot

The entry and exit of fixed vehicles is fully automated, without personnel on duty; temporary vehicles can pay parking fees by mobile phone or cash;

2. Reduce equipment failure rate

The equipment of the license plate recognition system is simple, no card issuer or card reader is needed, which reduces the failure rate of the parking lot system;

3. Improve user friendliness

Parking lot users do not need to carry any cards, and no longer worry about the trouble caused by forgetting to carry cards;

4. Reduce administrative work

There is no need to manage cards such as IC cards, such as card issuance and loss reporting, etc., reducing the management workload;

5. Reduce management costs for operators

There is no need to arrange personnel on duty at the entrance and exit, which greatly reduces labor costs and management costs;

6. Improve traffic efficiency

Vehicles entering and leaving the parking lot do not need to swipe their cards or park, which speeds up the speed of vehicles entering and leaving the parking lot and avoids congestion.

7. Improve security

The parking lot license plate recognition system can be networked with the law enforcement system to detect illegal vehicles in time and assist public security management.

With LPR, drivers can save time finding their cars, increase safety in parking lots by enhancing surveillance capabilities, reduce total management costs for operators, and even access additional revenue streams for property owners. By leveraging modern advanced technologies such as artificial intelligence (AI), machine learning techniques and smart cameras in tandem with effective rules-based analytics these real-time solutions can provide powerful efficiency increases across multiple industries. 

How much does LPR parking system cost?

A complete set of one-in-one-out license plate recognition system (including boom barrier, LPR camera and management software, etc.) ranges only from US$1,800 to US$3,000. We will develop the ideal solution according to your actual needs and buildings. Please feel free to contact our license plate recognition parking system experts, who will share more knowledge with you and help you save time and money. Contact us for free quote now.

Which algorithm is used in automatic number plate recognition?

The number plate recognition algorithm is the basis of the license plate recognition system. The image is collected, and then starting from the license plate texture, the separation notion is used to establish a number plate location preprocessing model based on directional fractal parameters, and the license plate area is extracted by combining the projection method, and then the characters are segmented and recognition, and finally output the result.
The basic algorithm process of license plate recognition includes the following 3 main parts:
(1) License plate positioning;
(2) Character segmentation;
(3) Character recognition.


What are the advantages of Macrosafe's license plate recognition algorithm?

1. There are various methods for license plate location, and they mainly include:
the use of gradient information projection statistics; 
the use of wavelet transform for segmentation; 
the algorithm of license plate area scanning and connection; 
the method of using regional characteristics to train classifiers, etc. 

This is the most critical first step in the license plate recognition algorithm. The quality of the effect directly affects the rate of license plate recognition. 

Macrosafe uses a heuristic license plate location algorithm, making the comprehensive license plate detection rate as high as 99.7%.

2. Character recognition is the core of the whole system. In its practical application, the most critical issue is the selection of character features. If the feature selection does not have a good degree of discrimination, not only the feature dimension is large but also it is difficult to obtain a better recognition effect. 

The large-scale neural network recognition algorithm used by Macrosafe has a comprehensive number plate recognition rate as high as 99.5%.

3. The similar characters on the license plate are relatively close in shape, affected by image resolution, light, and license plate stains. General classification algorithms are prone to misidentification. 

Based on this algorithm, Macrosafe license plate recognition system proposes special processing for confusing characters. Similar characters such as "2" and "Z", "0" and "D", etc., can be effectively recognized.
The recognition effect can still maintain a high recognition rate in any extremely complex situation.

Can LPR parking system detect no license plate?

Yes, Macrosafe LPR parking system can detect no license plate vehicles. The Macrosafe LPR algorithm uses the target detection method to detect unlicensed vehicles in the video.

The unlicensed vehicles we usually refer to generally refer to unlicensed automobiles, and non-automotive vehicles such as scooters, tricycles, motorcycles, and bicycles for the elderly.

can lpr detect no license plate?
can lpr detect non license cars

With the development of technology, the accuracy of camera recognition of license plates is much higher than before. And more and more parking lots use LPR parking systems.

However, there will still be situations where the LPR parking system cannot recognize the license plate.

The situations where the license plate recognition camera cannot recognize the license plate generally include the following situations:
1. For new cars, there are only temporary license plates;
2. The license plate number is so dirty that even the human eye cannot easily identify it;
3. The speed of the vehicle is too fast, the system cannot recognize it in time, and the owner does not cooperate with the second recognition when reversing;
4. Unrecognized due to the system or network caused by the recognition freeze.
In view of the above situations where the license plate cannot be recognized, targeted treatment
1. For vehicles with no license plate or license plate number that is too dirty, drivers can  scan the QR code to enter and exit smoothly.
2. For vehicles that have not been identified in time, admin can manually "input the license plate number" on the LPR parking system software. Exits can also be handled in the same way.
3. For m
onthly users:, they will be allow to exit directly without any fees.

What makes the Macrosafe ANPR system better than other suppliers?

There are two types of license plate recognition systems on the market: software recognition and hardware recognition. Software recognition refers to the use of computer algorithms to analyze images and identify license plates, while hardware recognition involves the use of professional cameras and sensors to capture and interpret license plate data. 

Macrosafe hardware-based license plate recognition (LPR) systems with built-in recognition modules offer several advantages over software-based LPR systems. Here are some key benefits:

1. Speed and Efficiency: Hardware-based LPR systems typically process license plate data much faster than software-based solutions. The built-in recognition modules are optimized to perform high-speed image processing, enabling quicker analysis and identification of license plates.

2. Reliability: Hardware-based LPR systems are often more reliable and accurate in license plate recognition. The built-in modules are specifically designed and calibrated to capture and interpret license plate images, leading to better detection rates and reduced false positives/negatives compared to software-based approaches.

3. Standalone Operation: Hardware-based LPR systems can function independently without relying on external computing resources. This makes them more suitable for applications where real-time or on-site processing is required, such as toll collection, parking management, or access control systems.

4. Adaptability to Environmental Factors: Built-in recognition modules in hardware-based LPR systems are designed to account for various environmental factors like lighting conditions, weather conditions, or vehicle speed. This enables the system to operate effectively in challenging environments with different lighting levels and weather conditions.

5. Security: Hardware-based LPR systems with built-in modules can enhance security by providing real-time identification of vehicles and license plates. These systems can be integrated with security systems to automate access control, intrusion detection, or law enforcement activities by quickly matching license plate data against a database of known vehicles.

6. Easy Integration: Hardware-based LPR systems are often designed with standardized interfaces, making them simpler to integrate with existing surveillance or management systems. They can seamlessly connect with other devices like cameras, barriers, or ticketing machines, allowing for a more streamlined and efficient overall solution.

Macrosafe provide more customizaiton functions and integration with your cureent system, welcome to contact our experts now.

Why hareware ANPR parking system is better than software-based ANPR parking system?

1. Pattern Analysis and Recognition:
- Hardware recognition system: Utilizes video stream analysis for real-time monitoring, offering continuous analysis within the monitoring range.
- Software recognition system: Relies on image analysis and recognition, capturing photos of vehicles within a designated range for analysis. However, recognition accuracy may be affected if the vehicle image is not optimal.

2. Recognition Trigger Method:
- Hardware recognition system: Requires no additional detection equipment and does not cause any ground damage. It offers optional ground sensing and video triggering with 24-hour image collection.
- Software recognition system: Relies on ground sensing, infrared, and other peripheral vehicle detection equipment. Certain engineering work is necessary for implementation.

3. Intelligent Algorithm Model:
- Hardware recognition system: Uses an intelligent fuzzy dot matrix recognition algorithm, ensuring high accuracy with a recognition rate of over 99.70%. Minimal human intervention is required.
- Software recognition system: Relies on OCR/font topology recognition algorithm, which often results in misreads. The accuracy rate is less than 90%, requiring continuous input of correct number plates.

4. Reliability and Stability:
- Hardware recognition system: Employs a special recognition device with high-speed DSP and dual CPU control, ensuring system reliability and stability.
- Software recognition system: Relies on software recognition, which is prone to frequent crashes. The computer needs to be restarted, leading to intermittent system paralysis.

5. Recognition Speed:
- Hardware recognition system: Offers vehicle license plate recognition speed of less than 0.4 seconds, fulfilling the requirements of high traffic flow scenarios.
- Software recognition system: Vehicle license plate recognition speed is greater than 3 seconds, or even longer, which is considered unacceptably slow.

6. Speed Adaptability:
- Hardware recognition system: Capable of accurately and quickly identifying vehicle speeds within the range of 0-120km/h. Suitable for high-speed applications.
- Software recognition system: Recognition rate significantly decreases when the vehicle speed exceeds 40km/h. Further improvements are needed, especially with the introduction of parking lot systems.

7. Environmental Adaptability:
- Hardware recognition system: Operates normally under various lighting conditions, including night, cloudy, and rainy conditions.
- Software recognition system: Recognition accuracy fluctuates greatly under the aforementioned lighting conditions, even at different times of the day.

number plate recognition sysetm in dark
8. Compatibility:
- Hardware recognition system: No industrial IO card support required. The control system (PLC) can directly work with different types of parking lots (e.g., IC, ID, paper tickets) for recognition and automatic printing of license plate numbers.
- Software recognition system: Relies on IO cards for vehicle detection and gate switching. The parking system only has embedded software and lacks hardware connections. The project volume is large, with numerous lines, and stability is compromised.

9. Shared Camera Functionality:
- Hardware recognition system: Can share cameras with the surveillance system without affecting the overall system performance.
- Software recognition system: Not supported as it could severely impact system stability and recognition rates.

10. Output Signals:
- Hardware recognition system: Enables real-time data output including vehicle images, license plates, recognition numbers, license plate colors, recognition reliability, traffic flow, and parking volume. It offers additional features such as static picture query for vehicle entry and exit and entrance and exit space guidance systems.
- Software recognition system: Lacks an output interface and primarily supports its own system without secondary development support.  

Software recognition systems are typically less expensive and easier to install, but may be less accurate in certain conditions such as low light or when license plates are dirty or obstructed. Hardware recognition systems may be more expensive than previous one, but can provide more reliable results in a wider range of environments. 

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