DESIGN AND IMPLEMENTATION OF AN AUTOMATED CAR PLATE NUMBER RECOGNITION SYSTEM

Abstract

Android platform has gained popularity in recent years in terms of market share and number of available applications. Android operating system is built on a modified Linux kernel with built-in services such as email, web browser, and map applications. In this paper, automatic number plate recognition (ANPR) was designed and implemented on Android mobile phone platform. First, the graphical user interface (GUI) for capturing image using built-in camera was developed to acquire car plate number in Nigeria. Second, the preprocessing of raw image was done using contrast enhancement, filtering, and straightening. Next, an optical character recognition (OCR) using neural network was utilized to extract texts and numbers. The proposed ANPR algorithm was implemented and simulated using Android SDK on a computer. The preliminary results showed that our system is able to recognize most of the plate characters by almost 88%. Future research includes optimizing the system for mobile phone implementation with limited CPU and memory resources, and geo-tagging of the image using GPS coordinates and online database for various mobile applications.

INTRODUCTION

1.1  Background of the study

Massive integration of information technology into all aspects of modern life caused demand for processing vehicles as conceptual resources in information systems. Because a standalone information system without any data has no sense, there was also a need to transform information about vehicles between the reality and information systems. This can be achieved by a human agent, or by special intelligent equipment which is able to recognize vehicles by their number plates in a real environment and reflect it into conceptual resources. Because of this, various recognition techniques have been developed and car plate recognition systems are today used in various traffic and security applications, such as parking, access and border control, or tracking of stolen cars.

A vehicle registration plate is a metal of plastic plate attached to a motor vehicle for official identification purposes. The registration identifier is a numeric or alphanumeric code that uniquely identifies the vehicle within the issuing region’s database. In some countries, the identifier is unique within the entire country, while in others it is unique within a state or province. Whether the identifier is associated with a vehicle or a person also varies by issuing agency. Depending on the country, the vehicle registration plate may be called a license plate, tag, car plate or number plate. Most governments require a registration plate to be attached to both the front and rear of a vehicle, although certain jurisdictions or vehicle types, such as motorboats  require only one plate, which is usually attached to the rear of the vehicle. National databases relate this number to other information describing the vehicle; such as the make, model, color, year of manufacture, engine size, type of fuel used, Vehicle Identification (Chassis) Number and the name and address of the vehicle’s registered owner or keeper.

The term access control refers to the practice of restricting entrance to a property, a building, or a room to authorized persons. Physical access control can be achieved by a human (a guard, bouncer, or receptionist) through mechanical means such as locks and keys, or through technological means such as access control systems.

Automatic car plate recognition (ACPR) is a mass surveillance method that uses optical character recognition on images to read vehicle registration plates. They can use existing closed-circuit television or road-rule enforcement cameras or ones specifically designed for the task. They are used by various police forces and as a method of electronic toll collection on pay-per-use roads and cataloging the movements of traffic or individuals.

ACPR can be used to store the images captured by the cameras as well as the text from the license plate, with some configurable to store a photograph of the driver. Systems commonly use infrared lighting to allow the camera to take the picture at any time of the day. ACPR technology tends to be region-specific, owing to plate variation from place to place.

The software aspect of the system runs on standard home computer hardware and can be linked to other applications or databases. It first uses a series of image manipulation techniques to detect, normalize and enhance the image of the car plate, and then optical character recognition (OCR) to extract the alphanumeric of the license plate. ACPR systems are generally deployed in one of two basic approaches: one allows for the entire process to be performed at the lane location in real-time, and the other transmits all the images from many lanes to a remote computer location and performs the OCR process there at some later point in time. When done at the lane site, the information captured of the plate alphanumeric, date-time, lane identification, and any other information required is completed in approximately 250 milliseconds. This information can easily be transmitted to a remote computer for further processing if necessary, or stored at the lane for later retrieval. In the other arrangement, there are typically large numbers of PCs used in a server farm to handle high workloads. Often in such systems, there is a requirement to forward images to the remote server, and this can require larger bandwidth transmission media.

During the 1990s, significant advances in technology took automatic car plate recognition systems from limited expensive, hard to set up, fixed based applications to simple “point and shoot” mobile ones. This was made possible by the creation of software that ran on cheaper PC based, non-specialist hardware that didn’t require the pre-defined angles, direction, size and speed in which the plates would be passing the cameras field of view.

1.2  Statement of Problem

Over the years, vehicles have been used to perpetrate crimes such as robbery and kidnapping. Auto theft has also been a major issue to the nation.

Law enforcement agencies are increasingly adopting automated car plate recognition (ACPR).ACPR systems function to automatically capture an image of the vehicle’s license plate,transform that image into alphanumeric characters using optical character recognition or similar software, compare the plate number acquired to one or more databases of vehicles of interest tolaw enforcement and other agencies, and to alert the officer when a vehicle of interest has been observed. The automated capture, analysis, and comparison of vehicle license plates typically occur within seconds, alerting the officer almost immediately when a wanted plate is observed.

Although the ACPR term includes a specific reference to “automated,” it should be noted that human intervention is needed insofar as the officer monitoring the equipment must independently validate that the ACPR system has accurately “read” the license plate, that the plate observed is issued from the same state as the one in which it is wanted, and to verify the currency of the alert, i.e., verifying that the reason this vehicle or the owner was wanted or of interest is still valid.Technologies to enhance their enforcement and investigative capabilities, expand their collection of relevant data, and expedite the tedious and time consuming process of manually comparing vehicle license plates with lists of stolen, wanted, and other vehicles of interest has to be developed. Police officers, sheriff deputies, and other law enforcement practitioners are often on the lookout for vehicles that have been reported stolen, are wanted in connection with a crime or traffic violation, are suspected of being involved in criminal or terrorist activities, are parking violation scofflaws, have failed to maintain current registration orto comply with statutory insurance requirements, or any of a number of other legitimate reasons.

1.3  Aim and Objectives of the study

The aim of this research work is to develop an application that will provide access control through automated car plate recognition.

The objectives of this study are as follows;

To assist law enforcement agencies in tracking stolen vehicles

To design a database that will serve as a repository for car plate numbers already registered.

To design a responsive system for crime detection

To ensure quick collection of data about vehicles within the scope of study.

1.4  Significance of the study

The proposed system will be of great advantage to Niger state law enforcement agency, Niger State Internal Revenue Service and other relevant authorities in the following ways;

ACPR can assist the police to identify persons of interest associated with criminal activity. According to a recent article, auto theft is associated with a wide range of criminal activities, including the offences of break and enter, armed robbery, and drug-related offences. In other words, offenders steal cars for use in the commission of additional offences. For example, drug offenders may steal from within cars, but may also steal the car to raise money to purchase drugs.

Improved Performance and Efficiency: There is no comparison between the number of plates an officer on patrol entering license plate information manually into an onboard computer and the number that automated ACPR technology can handle. With the potential ability to read up to 3,000 plates an hour, this technology can improve productivity. Not only does the system read plates rapidly, but hits are collected only on vehicles displaying license plates that match the desired criteria and appear in the database.

Increased Crime Detection: The substantially larger number of vehicles pulled over as a result of ACPR technology in patrol cars means that officers will come face to face with more criminals, generating more arrests. Officers attached to ACPR teams make 10 times more arrests than non-ACPR members. Arrests that are the result of ACPR stops are primarily for vehicle crimes, robbery, theft, burglary, and drug offenses. It is well known that car thieves steal cars not just to go for a drive but to help them commit other crimes such as breaking and entering, robbery, home invasion, and drug trafficking. In this way, ACPR technology can be valuable in preventing or solving many types of crime plaguing society.

1.5  Scope of the study

Every project is carried out to achieve a set of goals with some conditions keeping in mind that it should be easy to use, feasible and user friendly. As the goal of this project is to develop an application that will provide access control through automated car plate recognition, this system will be designed keeping in mind the conditions (easy to use, feasibility and user friendly) stated above. The proposed project’s intended users are; Niger State Law enforcement agencies, Computer Science Department and other relevant agencies.