KR20070044607A - System for recognizing regisration number plate of vechicle using image input signal through mobile phone - Google Patents

Abstract

The present invention provides a video input and transmission unit for real-time transmission of a continuous image input by taking a picture within the range of the license plate area of the driving vehicle from a portable terminal having a camera capable of taking a photograph;

An image capture and output unit configured to store and output an image transmitted from the image input and output unit, and extract a license plate region from an image image output from the image capture and output unit to read whether the extracted license plate region is recognizable. An image processing unit including a valid license plate determination unit,

And an image recognition unit including a database unit for storing and sorting vehicle license plate information read by the valid license plate determination unit in an optimal state order, and a license plate recognition unit for recognizing license plates in an optimal license plate state order in the database unit.

The vehicle license plate obtained by extracting a text area from the image image obtained by real-time photographing the license plate of the tracking inquiry vehicle using a portable terminal such as a PDA, can be connected to the central database and the central database to enable vehicle inquiry. The present invention relates to a license plate recognition system using a signal input to a portable terminal.

Image input and output unit, image capture and output unit, valid plate determination unit, database unit, license plate recognition unit

Description

Vehicle license plate recognition system using image input signal to portable terminal {System for recognizing regisration number plate of vechicle using image input signal through mobile phone}

1 is a block diagram of the present invention,

2 is a flowchart illustrating a flow of a process for determining a valid license plate in the present invention;

3 is a reaper illustrating a state in which an image obtained by photographing is output;

FIG. 4 is an image obtained by analyzing the saturation value deviation of each image obtained by FIG. 3;

FIG. 5 is an image illustrating a state in which only a text area is extracted by correcting yin and yang in the image of FIG. 4.

FIG. 6 is a flowchart illustrating a point in time at which the tracking is terminated at the same time as tracking the position of the license plate according to the tracking of the captured image image.

7 illustrates a flow for performing interworking vehicle information inquiry with the central DB after the license plate is recognized by aligning the license plates,

8 is a flowchart illustrating an end point determination flow for storing and terminating according to validity determined after image capturing;

9 illustrates a flow of aligning and recognizing license plate information using data of a license plate obtained.

※ Brief description of the main symbols in the drawings

100; Image input and output unit 200; Image processor

210; Image capture and output unit 220; Effective license plate judgment part

300; Image recognition unit 310; Database part

320; License plate recognition unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for recognizing a license plate of a driving vehicle by receiving an image image signal photographed and stored using a portable terminal as a text signal, and tracking tracking vehicle using a portable terminal such as a PDA. In the license plate recognition system using the image input signal to the portable terminal to enable the vehicle search by interlocking the license plate obtained by extracting the text area from the image image obtained by real-time shooting of the license plate with the central database and the central database It is about.

With the development of the industrial society, traffic accidents, vehicle theft accidents, traffic jams, parking problems, etc. are becoming very important social issues as vehicle growth increases. Accordingly, vehicle management, vehicle tracking, automatic toll billing, parking management, and arrangement of vehicles Many researches have been conducted to solve various problems as described above through the license plate recognition in the application field.

In general, the application number of the vehicle identification system is applied to the speed control system (fixed, portable, mobile), signal violation control system, toll evasion prevention system, runner window management system, digital camera, strobe (lighting device), It consists of a Grab Board, a license plate key controller, an automatic IRIS lens, and a loop coil.

An important core technology in such a vehicle identification system is that the main controller obtains a good image that can sufficiently recognize the vehicle number, which can be largely dependent on the state of the acquired image. Accuracy and reliability, and the state of the license plate affect the success rate of accurate recognition.

Conventionally, a system for recognizing a vehicle number inputs a real-time photographing method using a digital camera and a video image obtained from a video taken by a CCTV by a signal detected by a sensor when the vehicle enters, and uses the classified data to use the license plate Querying was a common license plate identification method.

One example of this is a photographing unit for transmitting an image of a vehicle by adjusting illuminance, focus, and focus of a vehicle entering a certain range, and a digital image for making and transmitting an analog image transmitted through the photographing unit as a digital image. A license plate area is found from a digital image received by the camera, a digital image received from the digital camera transmitted by the image acquisition unit using a license plate recognition program, and an image acquisition unit for placing a digital image transmitted from the digital camera into the main memory of an industrial computer. Presented as a license plate recognition unit that recognizes the information, it is installed in a general parking lot, an apartment building, an office building such as an officetel, used to determine whether the vehicle is authorized for parking, or installed in a toll gate or a checkpoint at a highway, To determine the back It discloses having to be used.

However, in the case of the license plate recognition system in the case described above, the limit of use of the license plate recognition system is limited only to the identification of vehicles authorized for parking in the various parking lots, the identification of crimes and stolen vehicles, and the like. It can be expected that the effect can be expected only within the space or area of the installation system is installed, there is a problem that it is impossible to recognize the license plate of the tracking vehicle when it is out of the installation area.

In addition, in the case of Korean Patent Registration Application No. 2001-28018, in order to extract the license plate image, it is converted into color coordinates and the converted image data is compared with the prepared reference color data to detect the vehicle license plate area, and then the image data is After the filtering is performed by diffusion filtering to leave only the license plate area, and then the license plate image data is extracted from the image data by the calculated coordinates of the license plate area, but the projected image data is projected onto a two-dimensional plane. There is a problem in that the identification of the vehicle license plate fails to detect the movement or the direction of movement of the vehicle.

In addition, Patent Registration Application No. 2003-97042, filed with the Korean Intellectual Property Office, discloses a device using a template-based correlation for recognizing a license plate using color image processing, but is also limited to a parking management system. It is a technology, and there is no operation of extracting valid data by checking validity of recognized data, thereby increasing a false recognition rate.

Accordingly, the present invention has been made to solve the above-mentioned problems, and overcomes the limitation of being installed in a fixed place such as a parking lot or other toll gate, and the data of the image image obtained by photographing the inquiry vehicle using a portable terminal. The purpose of the present invention is to accurately determine the validity of the license plate identification in the image obtained by extracting the license plate area and the textualized character area from the values.

The present invention for achieving the above object,

An image input and transmission unit 100 for real-time transmission of continuous images input by photographing an area within a range of a license plate of a driving vehicle from a portable terminal having a camera capable of capturing;

The image capture and output unit 210 which stores and outputs the image transmitted from the image input and output unit 100, and extracts the license plate area from the image image output from the image capture and output unit 210. An image processor 200 including a valid license plate determination unit 220 for reading whether the extracted license plate area is recognizable;

Database unit 310 for storing and sorting the license plate information read by the effective license plate determination unit 220 in the optimal state order, and license plate recognition for recognizing the license plate in the order of the optimal license plate state in the database unit 310 The image recognition unit 300 includes a unit 320.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In the present invention, as shown in Figure 1 showing the flow chart image transmission unit 100 for transmitting the image obtained by taking the image, and the license plate effective to receive the image transmitted from the image transmission unit 100 and arithmetic processing An image processing unit 200 comprising an image capturing and outputting unit 210 and an effective license plate determination unit 220, which is configured as a central control unit for reading the information and storing the data to be used as recognition information; The image recognition unit 300 is configured to recognize and recognize the license plate of the vehicle to be queried by the database unit 310 and the license plate recognition unit 320.

The image input and output unit 100 obtains an image of a vehicle license plate in motion and outputs the image image to an image processing unit which may be composed of an image capture and output unit 210 and an effective license plate determination unit 220. As a means for transmitting so that it may be a CCTV camera fixed to a predetermined position or a web camera can also have its configuration, preferably using a portable terminal, such as a PDA with a built-in camera of the tracking vehicle on the move The area including the license plate is photographed at various angles, thereby obtaining a plurality of images.

The image processing unit 200 displays the image image obtained through the portable terminal in the image input and output unit 100 described above in the image capture and output unit 210 and displays the image image on the vehicle license plate of the subject in the acquired image. It is a configuration for processing whether or not the validity through the valid plate determination unit 220.

That is, the image capturing and outputting unit 210 transmits and stores a plurality of image images obtained through a real-time connection process with a central server under the control of the central control unit through a portable terminal such as a PDA. Image data is caused to be displayed by the driving of image processing.

The effective license plate determination unit 220 extracts a license plate area and a character area that can be determined as a license plate from the display area after displaying a plurality of images inputted through the image capture and output unit 210 as described above. It is determined whether or not the video image in the extracted area range is a license plate having an image effective enough to be recognized by the license plate.

The process for determining the effective license plate includes the steps of displaying two consecutive image data (S1), analyzing the saturation value deviation of each image (S2), combining analysis data and removing invalid data (S3), A valid license plate data selection step (S4), license plate area and character area extraction step (S5), and valid license plate determination step (S6) will be described with reference to Figs.

(Step of displaying two consecutive image data- S1 )

Refers to a step of displaying two consecutive image images selected from the image images transmitted from the image input and output unit 100 (see FIGS. 1A and B).

(Horizontal of each image Saturation Value  Deviation Analysis Step S2 )

This process refers to analyzing the data of the two image images in the display step (S1), and compares and analyzes the difference between the subject position and color in the two image data of the previous image data and the current image data .

For example, a position in a frame in which saturation changes such as horizontal red, green, and blue values in the previous image data (for example, FIG. 3A) differ by more than a specific value is analyzed, and current image data (for example, FIG. 3B). Analyze changes in saturation such as red, green, and blue at the same position as the previous image data.

(Analysis Data Combination and Invalid Data Removal Step- S3 )

As described above, if the correlation of saturation change such as red, green, blue, etc. in the horizontal direction in each image is not found, or if the difference in the color signal is remarkably large, the process recognizes the invalid data and the corresponding data. This step is to remove (see Fig. 4).

By combining the data values after removing the invalidated data, a video image as shown in FIG. 4 can be obtained.

(Valid license plate data selection step- S4 )

By using the data after deleting the invalid data as described above, the area including the most similar elements to the license plate is obtained. The higher the saturation value of the letter part is expressed as embossment, the lower the saturation value is represented as intaglio. A video image as in 4 can be obtained to select a data value with a valid license plate area.

License plate area and character area extraction step S5 )

In this step, the data value selected through the valid license plate data selection step (S4) as described above is subjected to a process in which the license plate area and the character area are extracted.

As described above, the selected license plate area is divided into an intaglio and an embossment. In the case of an intaglio, when the inversion process is performed by inverting the saturation value, a high saturation value becomes a character area and a lower saturation value is represented as an underlying image. The license plate area and character area can be separated and extracted.

(Valid license plate determination step- S6 )

In this step, the license plate area and the character area extraction step (S5) are subjected to a process of determining the valid license plate that can recognize the vehicle number by comprehensively determining the arrangement, the slope, the size, etc. of the character data extracted in the image data. (See FIGS. 5 and 6)

On the other hand, as shown in Figures 6 and 8 it can provide a configuration that can control the location of the tracking and at the same time to track the location of the license plate according to the tracking of the captured image image. End point determination step-S60)

Such vehicle license plate tracking and end point determination step (S60) is a step (S6) of determining the validity of the license plate in the captured image image and the number of valid license plates when confirming that the invalid license plate number information is "0". An effective information storage step (S61) for storing information, a license plate edge determination step (S62) for determining whether the edge portion (EDGE) of the license plate is identified in the image of the continuous valid license plate, and the edge portion in the license plate If the output is composed of a normal end step (S63) that normally terminates the tracking of the license plate.

In addition, in the step of determining whether or not the validity (S6) is compared and grasped the information number (N) of the valid license plate and the information number (n) of the invalid license plate (S64), the information number (N) of the effective license plate is the information of the invalid license plate If the number is smaller than n, the step S65 is forcibly terminated.

That is, the vehicle license plate tracking and end point determination step (S60) may estimate the traveling direction of the vehicle and estimate the traveling speed of the vehicle. First, the license plate may be obtained from an image image obtained by using a camera or a portable PDA. Set the center point and analyze the trajectory where the center point of the set plate is moved.

Therefore, it can be seen that the vehicle is moved in the direction in which the license plate center point is moved through the analysis of the movement of the center point of the license plate.

In addition, the speed of the vehicle can be estimated by analyzing the rate of change of the license plate size.

In the present invention, it is confirmed that the most desirable data is obtained when the range of estimating the speed of the vehicle is within 30 km / h.

In addition, if the license plate is not sufficiently exposed to a terminal such as a fixed camera or a portable PDA with a built-in camera, or a temporary blockage occurs due to the interference of other objects during the entry of the vehicle, the direction and speed of travel of the license plate The end point of the determination of the decision should be determined. The end point may be determined by using the change of the latest position, direction, and size of the license plate.

That is, as shown in FIG. 8, the image transmitted from the image input and output unit 100 determines the effective license plate in the image processing unit 200 including the image capture and output unit 210 (220; S6). If judged to be valid license plate data, the invalid license plate information is reset to " 0 " to store the information (S61).

In this process, the driving direction and the traveling speed for the vehicle are tracked and analyzed by the information of the license plate data.

Here, if it is determined that the transmitted license plate image is invalid, the invalid license plate information is cumulatively added. When the invalid license plate information has a result exceeding a predetermined reference value (S64), the validity of the license plate plate is determined. Vehicle license tracking is forcibly terminated (S65).

Preferably, a predetermined reference value for forcibly stopping the validity determination is calculated based on the speed and the direction of travel.

On the other hand, the information that has been validated as described above is tracked the direction of the license plate to determine whether the edge portion in the license plate area (S62), and goes through the process of normal termination (S63).

As shown in FIG. 1, the image recognition unit 300 determines whether the image processing unit 200 is valid by the valid license plate determination unit 220, and stores a variety of data obtained therefrom. ) And a license plate recognition unit 320 for recognizing the license plate from the database unit 310.

The database unit 310 analyzes the valid license plate data secured through the valid license plate determination step S6 of the valid license plate determination unit 220, divides the license plate data into a plurality of pieces of information from one license plate data, and makes a database thereof. .

For example, the plurality of information partitions may be divided into a database by storing various pieces of information about the background color, the type, the character size, and the moving direction of the license plate.

In addition, a plurality of license plate data can be arranged according to the direction of movement of the license plate, can also be sorted according to the accuracy (see Fig. 7).

9 illustrates a flow of aligning and recognizing license plate information using data of a vehicle license plate obtained through the above process, after inputting corresponding information of the license plate from the database unit 310 (S70). Through the process of calculating the accuracy of the received information, each license plate is arranged in the order of accuracy (S71).

The license plate is enlarged and filtered by image processing in this way (S72) and the text portion of each character area is distinguished (S73). .

If an error occurs in this process (S75) it is repeated in the step of expanding and filtering the license plate (S72).

On the other hand, if normal recognition is made, the previous number of the license plate is checked (S76), and the result of the recognized license plate is output (S77), and then the license plate information is initialized (S79) to complete the license plate information sorting and recognition process.

On the other hand, if an error occurs in the previous number check process (S76), the result value is invalidated (S78) and initialized through the process of initializing the license plate information (S79), and ends using the data value according to the read result of the captured image image. The recognition process of the license plate will be terminated.

The above-described system of the present invention may be operated by one video input and output unit 100, but is provided with a plurality of channels (preferably 4 channels) to configure each of the video input and output units 100 at the same time. Of course, each channel can be operated in one system.

Therefore, according to the present invention, by using a terminal such as a portable PDA equipped with a camera, etc., the license plate of the vehicle to be tracked and retrieved is recorded in real time and transmitted to the central server side, and then the image image data value is calculated and processed. By providing a system capable of recognizing the information of the license plate, it is possible to expect the effect of extracting the vehicle number and recognizing the vehicle number with a separate module, regardless of the shooting angle and the shooting location for obtaining the image.

In addition, the present invention, by using the image image transmitted in real time can be immediately viewed the vehicle, and can provide accurate image by acquiring the captured image from various angles, it is possible to increase the accuracy of vehicle inquiry to query the stolen vehicle And it can be expected that the effect of expanding the use area by the inquiry of the arrangement vehicle.

Although one preferred embodiment of the present invention has been described using the accompanying drawings as described above, it is not limited to the embodiments of the present invention by those skilled in the art, and various changes and modifications are within the scope without departing from the same technical idea. May be possible from

Claims (7)

An image input and transmission unit 100 for real-time transmission of continuous images input by photographing an area within a range of a license plate of a driving vehicle from a portable terminal having a camera capable of capturing; The image capture and output unit 210 which stores and outputs the image transmitted from the image input and output unit 100, and extracts the license plate area from the image image output from the image capture and output unit 210. An image processor 200 including a valid license plate determination unit 220 for reading whether the extracted license plate area is recognizable; Database unit 310 for storing and sorting the license plate information read by the effective license plate determination unit 220 in the optimal state order, and license plate recognition for recognizing the license plate in the order of the optimal license plate state in the database unit 310 Vehicle license plate recognition system using the image input signal to the portable terminal, characterized in that consisting of an image recognition unit 300 including a unit (320). The method of claim 1, After the plurality of images inputted through the image capturing and outputting unit 210 are displayed, the image input signal is input to the portable terminal including extracting a license plate area and a character area that can be determined as license plates. License plate recognition system. The method of claim 1, The process for valid plate determination in the valid license plate determination unit 220, Displaying two consecutive image images selected from the image images transmitted from the image input and output unit 100 (S1); Analyzing the data of the two video images in the display step (S1) and analyzing the horizontal saturation value deviation of each image (S2), Analyzing valid data and invalid data among the data obtained by the saturation value deviation analysis step (S2) and combining the analyzed data using the analyzed data and removing the invalid data (S3); A valid license plate data selection step (S4) for calculating an area including the element most similar to the license plate by combining the data after deleting the invalid data in the analysis data combining and invalid data removing step (S3); The license plate area and the character area extraction step (S5) for extracting the license plate and the character area by inverting and embossing the saturation value having the negative data value after converting the data value by the valid license plate data selection step (S4). Wow, Effective license plate determination step (S6) to determine the effective license plate that can recognize the vehicle number by comprehensively determining the arrangement, the slope, the size, etc. of the characters in the image data extracted by the license plate area and character area extraction step (S5) Vehicle license plate recognition system using the image input signal to a portable terminal comprising a). The method of claim 3, wherein The valid license plate determination step (S6), A valid information storing step (S61) for storing information of the effective license plate number when confirming that the invalid license plate number information is "0"; License plate edge determination step (S62) for determining whether to check the edge (EDGE) of the license plate in the image of the effective license plate, and When the edge portion is output to the license plate, the vehicle license plate tracking and end point determination step (S60) is a normal termination step (S63) of terminating the tracking of the license plate normally, the image input signal to the portable terminal Vehicle license plate recognition system. The method of claim 4, wherein In step (S6), the information number N of the valid license plate and the number n of information of the invalid license plate are compared and grasped (S64). When the number is less than n, the license plate tracking system using a signal input to the portable terminal, characterized in that the license plate tracking and end point determination step (S60) comprising the step of forced termination (S65). The method of claim 1, The license plate recognition unit 320 Inputting corresponding information of the license plate from the database unit (310) (S70); Calculating and sorting accuracy of the inputted information (S71); Enlarging and filtering the license plate (S72); Distinguishing a character part in each character area in the enlargement and filtering step S72; Recognizing the text by recognizing the number and the Hangul area in the character area separated by the character part (S74); The vehicle using the signal input to the portable terminal comprising the step of checking the previous number of the license plate after the normal recognition (S76), and after outputting the recognized license plate results (S77) to initialize the license plate information (S79) and terminate (S79). License plate recognition system. The method of claim 6, If an error occurs in the step (S74) of recognizing the number and the Hangul area in the text area (S74) and the number is repeated in the step of expanding and filtering the license plate (S72), If an error occurs in the previous number confirmation process (S76), the result of the license plate recognition system using a signal input to the portable terminal comprising the step of invalidating the result value (S78) and initializing the license plate information (S79). .

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