KR20130110821A - Method and apparatus for detecting vehicle through detection of license plate - Google Patents

Abstract

PURPOSE: A method and a device of recognizing a vehicle by license plate recognition obtain information about the traffic situation on the roads by sharing the location of an adjacent vehicle with adjacent vehicles. CONSTITUTION: A green channel is extracted among red, green, and blue channels of an image with a license plate of an adjacent vehicle (S210). Noise is removed from the extracted green channel (S220). Spectrum equalization is applied to the green channel in which the noise is removed (S230). The license plate of the adjacent vehicle is recognized in the green channel with the spectrum equalization (S240). [Reference numerals] (AA) Start; (BB) End; (S210) Extract a green channel from a photographed image; (S220) Remove noises from the green channel; (S230) Apply a spectrum equalization process; (S240) Recognize a license plate

Description

Vehicle recognition method and device through license plate recognition {METHOD AND APPARATUS FOR DETECTING VEHICLE THROUGH DETECTION OF LICENSE PLATE}

The present invention relates to a method for recognizing a location of a surrounding vehicle of a vehicle, and more particularly, recognizes a license plate of a surrounding vehicle from front, rear, or both images obtained through a vehicle camera or a black box. It relates to a method for recognizing.

Recently, devices for convenience of consumers as well as consumer satisfaction with power performance of automobiles are widely used. For example, the prevalence of the front, rear, left and right cameras for parking assistance and the integrated display device that can grasp the state of the car at a glance is becoming more common. The driver can see obstacles around the vehicle and know the distance to the obstacle through the camera and the distance measuring sensor and the display device provided in the front or rear of the vehicle at the front or rear parking.

In addition, research is being conducted to recognize other vehicles in the vicinity and use them for additional convenience functions of the vehicle. For example, the surrounding vehicle location technology may be used for a traffic information system or a security system.

Accordingly, there is a need for development of a method of recognizing a neighboring vehicle capable of introducing additional convenience functions of a vehicle beyond the conventional vehicle surrounding information for parking assistance.

The present invention is to propose a method for recognizing the surrounding vehicle by recognizing the license plate of the surrounding vehicle through the processing of the image acquired through the camera, etc., and further measures the distance to the surrounding vehicle, and through this traffic information or We will provide a way to create and use security information.

According to an embodiment of the present invention, a method of recognizing a vehicle by recognizing a license plate from a captured image is disclosed. The method includes extracting a green channel among red, green, and blue channels of an image of a license plate of a surrounding vehicle. ; Removing noise from the extracted green channel; Applying spectrum equalization to the noise-free green channel; And recognizing license plates of surrounding vehicles in the green channel to which the spectral equalization is applied.

The method may further include calculating a distance to the recognized neighboring vehicle by comparing the number of the recognized surrounding vehicle number plate with a size of a previously stored reference number.

The method may further include outputting a warning sound if the calculated distance is within a threshold.

The method may further include storing the calculated distance together with the photographed image.

The method may further include transmitting GPS information of the current location, the number of the recognized surrounding vehicle, and the calculated distance information to the recognized surrounding vehicle to a server. The method may further include displaying, by the server, the number of the recognized surrounding vehicle on a map according to the GPS information and the calculated distance to the recognized surrounding vehicle.

An apparatus for recognizing a vehicle by recognizing a license plate from an image taken according to an embodiment of the present invention is disclosed, wherein the device extracts a green channel among red, green, and blue channels of an image of a license plate of a nearby vehicle, The license plate recognizing unit may include a license plate recognizing unit configured to remove noise from the extracted green channel and apply spectral equalization to the green channel from which the noise is removed to recognize license plates of surrounding vehicles.

The apparatus may further include a distance calculator configured to calculate a distance to the recognized neighboring vehicle by comparing the number of the recognized surrounding vehicle number plate with a size of a previously stored reference number.

The apparatus may further include an output configured to output a warning sound if the calculated distance is within a threshold.

The apparatus may further include a storage configured to store the calculated distance together with the photographed image.

The apparatus may further include a communication unit configured to transmit GPS information of a current location, a number of the recognized surrounding vehicle, and calculated distance information to the recognized surrounding vehicle to a server. The communication unit may be configured to receive a map displaying the number of the recognized surrounding vehicle according to the GPS information and the calculated distance to the recognized surrounding vehicle from the server.

According to an embodiment of the present invention, the distance between the surrounding vehicle and the surrounding vehicle may be determined, and information about the traffic situation of the surrounding road may be obtained by sharing the position of the surrounding vehicle with the surrounding vehicles.

In addition, the shared location information of surrounding vehicles may be utilized for cracking of stolen vehicles or wanted vehicles.

1 is a block diagram of an apparatus for recognizing a surrounding vehicle through license plate recognition and a server for collecting information thereof according to an embodiment of the present invention.
2 is a flowchart illustrating a method for recognizing a license plate of a surrounding vehicle from an image photographing the surrounding vehicle according to an exemplary embodiment of the present invention.
3 is a flowchart illustrating a further method of utilizing the method for recognizing the license plate of the surrounding vehicle according to an embodiment of the present invention.
4 is a flowchart illustrating a further method of using the method for recognizing the license plate of the surrounding vehicle according to an embodiment of the present invention.
5 shows a map displaying recognized license plate information and distance information according to an embodiment of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and should be construed in a sense and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are included. Therefore, It is to be understood that equivalents and modifications are possible.

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

1 is a block diagram of an apparatus for recognizing a surrounding vehicle through license plate recognition and a server for receiving and collecting information from the apparatus, according to an embodiment of the present invention.

The surrounding vehicle recognition apparatus 100 may include an image collecting unit 110 configured to collect surrounding images of a measurement vehicle; A license plate recognition unit 121 configured to process the collected images to recognize license plates of nearby vehicles; A distance calculator 122 configured to calculate a distance to the surrounding vehicles by measuring the size of the recognized surrounding vehicle license plate; A communication unit 131 configured to transmit license plate information and the calculated distance information of the surrounding vehicles to a server; An output unit 132 configured to output a voice alert or a visual alert when the calculated distance is less than a predetermined distance; And a GPS receiver 133 configured to obtain a current location.

The image acquisition unit 110 corresponds to various cameras including a front or rear camera or a camera built in a black box provided in the measurement vehicle. The image collecting unit 110 photographs a surrounding vehicle located in front, rear or side of the measurement vehicle, and may be configured to photograph a license plate of the surrounding vehicle.

The license plate recognition unit 121 may be configured to recognize a license plate of a surrounding vehicle in the photographed or collected surrounding image. The license plate recognition unit 121 may go through a series of procedures to recognize the license plate of the surrounding vehicle.

The result of the method of recognizing the license plate from the collected image may be affected by the weather at the time of capturing the image or the surrounding environment. For example, if the weather was very cloudy or night, the collected images would be generally dark, which could interfere with the performance of the algorithm for license plate recognition. Therefore, when the brightness of the captured or collected image is darker than a certain level, separate image processing is required, which is intended to be proposed in an embodiment of the present invention.

Conventionally, the WDR (Wide Dynamic Rage) image sensor is mounted on the camera module in order to acquire the brightness of a captured or collected image to a certain level or more. none. In addition, although brightness may be corrected through an auxiliary light such as a flash while shooting an image, it is virtually impossible to use the auxiliary light because a camera module mounted in the vehicle generally needs to operate while driving the vehicle.

Therefore, through an embodiment of the present invention to propose a license plate recognition method according to the image processing.

The license plate recognition unit 121 may obtain information about brightness of a photographed or collected image. If the information about the obtained brightness is greater than or equal to the threshold, license plate recognition may be performed through general image processing without performing image processing according to an embodiment of the present invention. However, license plate recognition according to an embodiment of the present invention may be performed regardless of the obtained information about brightness.

The license plate recognition unit 121 may extract a green channel among red, green, and blue (RGB) channels of the photographed or collected image. In addition, noise may be removed by applying a local average filter to the extracted green channel. Thereafter, spectral equalization may be applied to the green channel from which the noise is removed to correct the brightness of the captured or collected image to a certain level or more.

Through this procedure, the license plate recognition unit 121 may recognize the license plates of the surrounding vehicles from the photographed or collected images.

The distance calculator 122 may calculate the distance to the surrounding vehicle by comparing the number of the recognized number plate of the surrounding vehicle and the size of the reference number stored in advance.

The reference number may be a plurality, and for example, one reference number may be prepared for each constant distance 1m from the measurement vehicle. That is, the size of each reference number may be a reference value including distance information.

In other words, the size of the reference number is a value obtained by measuring the number of the license plate while changing the distance through the camera, etc., for example, may be defined as shown in Table 1 below.

Height of base number in pixels Distance (meters) 5 4 6 3 7 2 8 One

In Table 1, the height of the reference number is used as a comparison criterion, but the width of the reference number or the height and width of the recognized license plate may be used as a comparison criterion. On the other hand, the information provided in Table 1 is only an example and does not limit the present invention.

Accordingly, by comparing the size (eg, height) of the number of the recognized license plate with the size (eg, height) of the reference number, if the distance information corresponding to the reference number having the same size is confirmed, The separation distance can be calculated.

The communication unit 131 is configured to transmit the license plate information and the calculated distance information of the surrounding vehicle to the server, thereby transmitting the license plate information of the surrounding vehicle and the location of the surrounding vehicle to the server 200 or other vehicles. Share with.

In addition, the output unit 132 may be configured to output a voice alert or a visual alert when the calculated distance is less than a predetermined distance. Since the surrounding vehicle recognition apparatus 100 according to an exemplary embodiment of the present invention is generally provided in a vehicle, the driver of the vehicle equipped with the apparatus 100 warns the driver to enlarge the space between the vehicles when the distance to the surrounding vehicle is near. can do. For example, the output unit 132 may include a display unit or a speaker.

In addition, the GPS receiver 133 is configured to obtain a current position, through which the position of the apparatus 100, i.e., the position of the measurement vehicle, can be known and the position of the surrounding vehicle can be utilized by utilizing the distance information to the surrounding vehicle. You can also see.

In addition, the storage unit 134 may store license plate information and the calculated distance information of the surrounding vehicles, and may store information about the reference number. In addition, the storage unit 134 may store a map and address information for a navigation function using the output unit 132.

The server 200 may receive license plate information of the surrounding vehicles, distance information to the surrounding vehicles, and current GPS information from each vehicle. The server 200 may collect and analyze the received information and synthesize or display the received information on a map. The map reflecting this information may be provided to each vehicle again.

The map reflecting such information may be used for traffic situation information, and a crime prevention effect for tracking a stolen vehicle or a wanted vehicle can be obtained.

2 is a flowchart illustrating a method for recognizing a license plate of a surrounding vehicle from an image photographing the surrounding vehicle according to an exemplary embodiment of the present invention.

The method includes recognizing a vehicle by recognizing a license plate from an image photographed by a camera, comprising: extracting a green channel among red, green, and blue channels of an image of photographing a license plate of a surrounding vehicle (S210); Removing noise from the extracted green channel (S220); Applying spectrum equalization to the noise-free green channel (S230); And recognizing license plates of surrounding vehicles in the green channel to which the spectral equalization is applied (S240).

Prior to the step S210 of extracting the green channel from the captured image, a procedure of acquiring brightness information of the captured image may be preceded. The method of recognizing the license plate of the vehicle from the photographed image may be affected by the weather or time at the time when the image is captured.

For example, in the case of an image captured at night, since the brightness is dark, it may not be easy to recognize the license plate of the vehicle in the captured image. However, in the case of an image photographed during the day, since the brightness of the image is higher than a certain level, it may be possible to recognize the license plate of the vehicle in the photographed image without additional image processing.

Therefore, before performing image processing on the photographed image, the brightness information of the photographed image is acquired, and if the brightness value is greater than the threshold value, the license plate recognition is performed without the image processing and if the brightness value is less than the threshold value, It may be configured to perform image processing.

The green channel may be extracted from the red, green, and blue channels constituting the image from the captured image (S210). Thereafter, noise may be removed from the extracted green channel (S220). You can use a local average filter to remove the noise.

Spectrum equalization may be applied to the green channel from which the noise is removed (S230). If spectral equalization is applied to one image, the brightness of each pixel of the one image can be evenly distributed. Accordingly, it is possible to easily extract the information from the dark image by converting the dark image relatively bright.

Then, the license plate of the surrounding vehicle may be recognized in the green channel to which the spectral equalization is applied (S240). Since the brightness of the photographed image or its green channel which has passed through S210 to S230 is corrected, the license plate of the vehicle can be recognized therefrom even if the first photographed image is a dark image.

3 is a flowchart illustrating a further method of utilizing the method for recognizing the license plate of the surrounding vehicle according to an embodiment of the present invention.

The license plate of the surrounding vehicle may be recognized from the captured or collected image (S310). The license plate recognition may be performed through S210 to S240 described with reference to FIG. 2.

Then, the distance to the surrounding vehicle may be calculated through the recognized license plate of the surrounding vehicle (S320). In the license plate of the recognized surrounding vehicle, the size of the number in the license plate may be measured. In the storage unit 134 illustrated in FIG. 1, a plurality of reference numbers and a separation distance corresponding to the reference numbers may be stored. The distance to the surrounding vehicle may be calculated by comparing the number size in the measured license plate with the size of the reference number. In this regard, since it has been described above with reference to FIG. 1, a detailed description thereof will be omitted.

The license plate of the neighboring vehicle thus recognized and information about the distance to the surrounding vehicle may be transmitted to the server 200 (S330). In addition, the GPS information of the current location obtained through the GPS receiver 133 may be transmitted to the server.

For example, the information transmitted to the server 200 is illustrated in Table 2 below.

Vehicle information 11 1111 GPS reception information 37.390243 / 126.973457 Current location Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do Nearby Vehicle Information the car's number  Distance (meters) 22 or 2222 3 33 slut 3333 4

4 is a flowchart illustrating a further method of using the method for recognizing the license plate of the surrounding vehicle according to an embodiment of the present invention.

The server 200 may receive license plate information of the surrounding vehicles, distance information to the surrounding vehicles, and current GPS information from each vehicle (S410). The server 200 may receive the information illustrated in Table 2 from each vehicle.

The server 200 may collect and analyze the received information and synthesize or display the received information on the map (S420). Referring to Table 2, it is possible to grasp the information and location information of the vehicle transmitting the information.

Accordingly, the server 200 may collect all information in a certain geographic area based on the "vehicle information" and "GPS reception information" of Table 2, and may analyze the information and display it on a map.

For example, an example in which the information shown in Table 2 is transmitted to a server and displayed on a map is shown in FIG. 5. The measurement vehicle is indicated by a black circle, and the surrounding vehicle recognized by the measurement vehicle is indicated by a white circle.

The map reflecting this information may be provided to each vehicle again. Alternatively, the server 200 may provide each vehicle with information such as Table 2 collected from several vehicles instead of a map. Each vehicle that has received such information may combine and display a map stored in the storage 134 through the output unit 132 in the vehicle.

Such information or a map in which the information is reflected may be used for traffic situation information, and a security effect for tracking a stolen vehicle or a wanted vehicle can be obtained.

Having described the embodiments of the present invention above, those of ordinary skill in the art will recognize that these embodiments are illustrative rather than limiting, and that various changes and modifications may be made without departing from the scope or spirit of the invention Variations, and modifications may be made without departing from the scope of the present invention.

110: image collector 121: license plate recognition unit
122: distance calculation unit 131: communication unit
132: output unit 133: GPS receiver
200: Server

Claims (12)

A method of recognizing a vehicle by recognizing a license plate from a captured image,
Extracting a green channel among red, green, and blue channels of an image of a license plate of a surrounding vehicle;
Removing noise from the extracted green channel;
Applying spectrum equalization to the noise-free green channel; And
And recognizing license plates of surrounding vehicles in the green channel to which the spectral equalization is applied.
The method of claim 1,
And calculating a distance to the recognized surrounding vehicle by comparing the number of the recognized surrounding vehicle license plate number with a size of a previously stored reference number.
3. The method of claim 2,
And outputting a warning sound when the calculated distance is within a threshold value.
3. The method of claim 2,
And storing the calculated distance together with the photographed image.
3. The method of claim 2,
And transmitting the GPS information of the current location, the recognized surrounding vehicle number, and the calculated distance information to the recognized surrounding vehicle to a server.
The method of claim 5,
And displaying, by the server, a number of the recognized surrounding vehicle on a map according to the GPS information and the calculated distance to the recognized surrounding vehicle.
A device for recognizing a vehicle by recognizing a license plate from a captured image,
Extract the green channel among the red, green and blue channels of the image of the license plate of the surrounding vehicle, remove the noise from the extracted green channel, and apply spectral equalization to the green channel from which the noise is removed And a license plate recognition unit configured to recognize license plates of surrounding vehicles.
The vehicle of claim 7, further comprising a distance calculator configured to calculate a distance to the recognized surrounding vehicle by comparing the number of the recognized surrounding vehicle number plate with a size of a reference number stored in advance. Recognition device.
The vehicle recognition apparatus of claim 8, further comprising an output unit configured to output a warning sound when the calculated distance is within a threshold.
The vehicle recognition apparatus of claim 8, further comprising a storage unit configured to store the calculated distance together with the photographed image.
The vehicle recognition system of claim 8, further comprising a communication unit configured to transmit the GPS information of the current location, the number of the recognized surrounding vehicle, and the calculated distance information to the recognized surrounding vehicle to a server. Device.
The method of claim 11, wherein the communication unit:
And receive a map displaying, from the server, the number of the recognized surrounding vehicle according to the GPS information and the calculated distance to the recognized surrounding vehicle.

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