The Difference and Contrast between Hard Recognition and Soft Recognition in License Plate Recognition

Qingdao license plate recognition, Qingdao Road gate
With the development of the industry and the various demands of the market, the market demand for license plate recognition system (Qingdao license plate recognition system) is more and more common, mainly divided into: software recognition and hardware recognition. After automatic identification, automatic login and automatic comparison of license plate numbers, the system can complete many intelligent functions such as automatic gate opening, automatic charging, automatic verification of user's vehicle identity, automatic identification of internal and external vehicles, automatic calculation of vehicle number, automatic alarm, etc.

Software identification: it is obvious that the meaning of the word can be understood through the software to stop the license plate number, and through the installation of a matching license plate identification software on the computer to stop the identification and disposal of captured pictures. The working method is to continuously capture a plurality of photos through a camera, select one of which is clearer, and then stop character processing through computer software to complete plate identification. The speed of soft recognition is slow because each recognition requires capturing multiple pictures. Moreover, the system is also extremely demanding for the captured pictures, and it must be extremely clear to achieve the desired effect. The system has a very high request for on-site environment and debugging quality. It is not suitable for many places where the environment is not pessimistic. The arrangement of equipment is very important.

Hardware identification: The simple explanation is to stop a series of character processing for captured pictures through independent hardware equipment; At present, there are also two kinds of hardware identification in the parking lot system industry, i.e. with a separate license plate identification instrument and front-end hardware identification. The front-end hardware identification is mainly used by AVR.

The front-end hardware identification integrated camera meets the market demand and is currently liked by a wide range of customers. The AVR front-end hardware recognition is also called an integrated license plate recognition camera, which embeds a traditional separate license plate recognition instrument into the camera to complete the integration of the front-end hardware and the camera, and successfully completes a series of tasks such as image capture, video transmission, character recognition, gate lifting, etc.
Comparison of Advantages between Soft Recognition and Hard Recognition;

1, analyze the identification form:
Hard identification system: video stream analysis and identification is adopted to stop all-weather real-time analysis of video streams within the monitoring range;
Soft identification system: picture analysis and identification, stop taking photos of vehicles arriving within the specified range, and then stop analyzing photos; When the position of the vehicle is not good, identification is prone to errors.


2. Trigger identification mode:
Hard identification system: optional ground sense and video trigger, no need to add detection equipment, no need to destroy the air or add projects, 24-hour image acquisition.
Soft identification system: triggered by peripheral vehicle detection equipment such as ground sense and infrared; Need a certain amount of work.


3. Intelligent algorithm model
Hard identification system: intelligent vague lattice identification algorithm is adopted, with higher accuracy rate and identification rate greater than 99.70%. Human intervention is rarely required.
Soft Recognition System: OCR/ Font Topological Structure Recognition Algorithm will frequently present misrecognition with an accuracy of less than 90%. Requires manual input of corrected number plates from time to time.


4. Reliability and Stability:
Hard identification system: The special identification device adopts TI's high-speed DSP and dual CPU control to ensure the reliability and stability of the system.
Soft identification system: software identification is prone to frequent crashes and other conditions, requiring frequent computer restart, resulting in continuous system paralysis.


5. Identification speed:
Hard identification system: the vehicle license plate identification speed is less than 0.4 seconds, which fully meets the demand when the traffic volume is large;
Soft Recognition System: Vehicle license plate recognition speed is greater than 3 seconds or even longer, which makes people unbearable.


6. Speed compliance:
Hard identification system: the vehicle speed can be stably and rapidly identified within the range of 0-120 km/h; The scope of application is widespread, and this kind of equipment is used for high-speed kilometers.
Soft identification system: when the vehicle speed is more than 40Km/H, the identification rate drops sharply, which is now introduced into the parking lot system and needs further improvement.


7. Environmental Compliance
Hard identification system: it can work normally under various lighting conditions such as night, cloudy day and rainy day.
Soft Recognition System: Under the above conditions, the recognition accuracy rate fluctuates greatly even at different times of the day.


8. Compatible Ability
Hard identification system: without the support of industrial IO card, the borrow parking lot control system (PLC) can be directly and seamlessly compatible with various types of IC, ID, paper tickets and other parking lots, completing the functions of automatic identification and automatic printing of license plate numbers only when the license plate number and card number are different from each other.
Soft identification system: it relies on IO card to stop vehicle detection, switch Road gates and other actions. It has only software embedded relationship with parking lot system and has no contact with hardware. Large quantities of work, many lines, poor stability.


9. camera commonality
Hard identification system: the system can share cameras with the monitoring system without any influence on the system.
Soft identification system: cannot be shared, otherwise it will seriously affect system stability and identification rate.


10. Output Signal
Hard identification system: the system can output real-time data such as large vehicle map, small number plate map, number plate identification number, number plate color and identification credibility, traffic flow, parking volume in the yard, etc. It has the function of querying static pictures of vehicles entering and leaving, and can be connected with parking space guidance system, etc.
Soft identification system: there is no output interface, which is used by the system itself and cannot stop secondary development.