System for automatic recognizing license number of other vehicles on observation vehicles and method thereof

• US 7,412,078 B2
• Filed: 07/18/2002
• Issued: 08/12/2008
• Est. Priority Date: 07/18/2001
• Status: Expired due to Fees

• Current Assignee: INPEG Vision Co., Ltd.
• Original Assignee: Hyunjae Tech Co., Ltd.
• Inventors: Kim, Sung Ho
• Primary Examiner(s): Bella; Matthew C.
• Assistant Examiner(s): TUCKER, WESLEY J
• Application Number:
  US10/482,959
• Publication Number:
  US 20040218785A1
• Time in Patent Office: 2,217 Days
• Field of Search: 382/100, 382/105
• US Class Current: 382/105
• CPC Class Codes: G08G 1/0175 by photographing vehicles, e.g. when violating traffic rules
• CPC Class Codes: G08G 1/054 photographing overspeeding vehicles

Abstract

The present invention relates to a system and method for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, which mounts automatic license plate number recognition equipment including a camera to a vehicle such as police patrol car, security company car, taxi, and so on, recognizes the license plate of a different vehicle on the run or in parking or stopping through the camera, verifying whether the vehicle is stolen, in search, or has a forged license plate, and can deal with the vehicle early when the vehicle is in question.

Claims

1. A system for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, the subject vehicle being on the run or in parking or stopping, comprising:

the surveillance vehicle having a camera for photographing license plate information of the subject vehicle on the run or in parking or stopping, a surveillance part for extracting a license plate number of the subject vehicle based on data photographed through the camera, receiving result data on whether the subject vehicle is one in a question from a server computer verifying whether the subject vehicle has a problem based on the extracted license plate number of the subject vehicle for notifications to a driver or a passenger in characters or by voice, and a portable communication device for transferring the license plate number of the subject vehicle extracted from the surveillance part through a communication network; and

the server computer for periodically receiving information on vehicles in the questions from computers of processing institutions that control and manage vehicles through the communication network for building a database, and, if the license plate number of the subject vehicle is received from the portable communication device equipped in the surveillance vehicle via the communication network, comparing the license plate number of the subject vehicle with the vehicle information stored in the database for identifications on whether the subject vehicle is in the question, and transferring result data on whether the subject vehicle has a problem to the portable communication device equipped in a corresponding surveillance vehicle,

wherein the surveillance part equipped in the surveillance vehicle includes;

a key manipulation part for inputting a key manipulation signal of a driver or a passenger of the surveillance vehicle to recognize the license plate number of the subject vehicle;

a photographing data input part for inputting the photographing data of the subject vehicle photographed via the camera;

a control part for controlling an extractions of the license plate number of the subject vehicle based on the photographing data of the subject vehicle inputted through the photographing data input part, controlling an transfer of the extracted license plate number of the subject vehicle to the server computer through the portable communication device, and controls outputs of result data on whether the subject vehicle is in question which is received from the server computer verifying whether to be one in question based on the license plate number of the subject vehicle for driver'"'"'s or passenger'"'"'s identifications;

a vehicle license plate number recognition part for extracting the license plate number of the subject vehicle based on the photographing data of the subject vehicle inputted through the photographing data input part according to the control of the control part;

a database for storing various programs necessary for operations of the surveillance part and an automatic vehicle license plate number recognition program for extracting the license plate number of the subject vehicle based on the photographing data of the subject vehicle photographed by the camera;

a display part for displaying result data on whether the subject vehicle is one in question which is received from the server computer through the portable communication device according to the control of the control part;

a voice output part for converting the result data on whether the subject vehicle is in question which is received from the server computer through the portable communication device according to the control of the control part for an output through speakers; and

a communication interface connected to the portable communication device equipped in the surveillance vehicle for communications, outputs the license plate number of the subject vehicle according to the control of the control part to the portable communication device, and outputs to the control part the result data on which the subject vehicle is in question which is inputted from the server computer through the portable communication device.

2. The system as claimed in claim 1, wherein the server computer includes:

a data communication part for periodically inputting information on vehicles in the questions from the computers of the processing institutions, receiving the license plate number of the subject vehicle from the portable communication device equipped in the surveillance vehicle through the communication network, and transferring the result data on whether the subject vehicle is in question which is inputted from a main control part to the portable communication device equipped in a corresponding surveillance vehicle;

the main control part for controlling the building of a database for information on vehicles in the question, which is inputted from the computers of the processing institutions, comparing the license plate number of the subject vehicle with the vehicle information stored in the database based on the license plate number of the subject vehicle received from the portable communication device equipped in the surveillance vehicle through the data communication part for identifications on whether the subject vehicle is in question, and controlling a transfer of the result data on whether the subject vehicle is in question to the portable communication device equipped in a corresponding surveillance vehicle; and

a database for storing and updating the information on vehicles in various questions such as theft or search which is inputted from the computers of the processing computers according to the control of the main control part.

3. The system as claimed in claim 1 or claim 2, wherein the server computer determines whether a corresponding surveillance vehicle can deal with the subject vehicle if the subject vehicle is in question when verifying whether the subject vehicle has a problem in comparison of the information on vehicles in various question such as theft or search stored in the database based on the license plate number of the subject vehicle which is received from the portable communication device equipped in a particular surveillance vehicle, and transfers, for processing, the information on the subject vehicle(license plate number of the subject vehicle, present location, and the like) verified as a vehicle in question to the computers of the processing institution if the corresponding surveillance vehicle can not deal with the subject vehicle verified as a vehicle in question.

4. A system for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, the subject vehicle being on the run or in parking or stopping, comprising:

the surveillance vehicle having;

a camera for photographing license plate information of the subject vehicle on the run or in parking or stopping,

a surveillance part for extracting the license plate number of the subject vehicle based on data photographed via the camera, comparing the extracted license plate number of the subject vehicle with information on vehicles in the question which is stored in a database for verifications on whether the subject vehicle is in question, notifying a driver or a passenger in characters or by voice of result data on whether the subject vehicle is in question, and recording discovery of a vehicle in question if impossible to notify a server computer of notification of a result on whether the subject vehicle is in question, and

a portable communication device for receiving information on vehicles in question which is periodically updated from the server computer and transferring to the server computer through the communication network information on the subject vehicle verified as a vehicle in question if possible to notify the server computer of a result as to whether the subject vehicle is in question; and

the server computer for periodically receiving information on vehicles in the question from computers of processing institutions that control and manage vehicles through the communication network for building a database, transferring the information on vehicles in question which is periodically updated to the portable communication device equipped in each surveillance vehicle through the communication network, and storing in the database the information on the subject vehicle verified as a vehicle in the question which is received from the portable communication device equipped in the surveillance vehicle through the communication network,

wherein the surveillance part equipped in the surveillance vehicle includes;

a key manipulation part for inputting a key manipulation of a driver or a passenger of the surveillance vehicle for recognition of the license plate number of the subject vehicle;

a photographing data input part for inputting photographing data of the subject vehicle which is photographed through the camera;

a control part for controlling the storage of information on vehicles in various question such as theft and search which is periodically received from the server computer, controlling the extraction of the license plate number of the subject vehicle based on the photographing data of the subject vehicle which is inputted through the photographing data input part, comparing the extracted license plate number of the subject vehicle with the information on vehicles in question stored in the database for verifying whether the subject vehicle is in question, controlling outputs of result data on whether the subject vehicle is in question in characters or by voice for driver'"'"'s or passenger'"'"'s verifications, and storing in the database discovery of a vehicle in question if impossible to notify the server computer of a result as to whether the subject vehicle is in question;

a license plate number recognition part for extracting the license plate number of the subject vehicle based on the photographing data of the subject vehicle which is inputted through the photographing data input part according to the control of the control part;

the database for storing various programs necessary for operations of the surveillance part and an automatic license plate number recognition program for extracting the license plate number of the subject vehicle based on the photographing data of the subject vehicle which is photographed by the camera, storing and updating the information on vehicles in various questions such as theft and search which is periodically received from the server computer, and storing the discovery of a vehicle in question according to the control of the control part;

a display part for displaying the result data as to whether the subject vehicle is in question according to the control of the control part;

a voice output part for converting into voice the result data as to whether the subject vehicle is in question according to the control of the control part for an output through speakers; and

a communication interface connected for communications to the portable communication device equipped in the surveillance vehicle, and for outputting to the control part the information on vehicles in various questions such as theft and search which is periodically received from the server computer through the portable communication device, and outputting to the portable communication device the information on the subject vehicle verified as a vehicle in question according to the control of the control part.

5. The system as claimed in claim 4, wherein the server computer includes:

a data communication part for transferring to the portable communication device equipped in the surveillance vehicle through the communication network the information on vehicles in the question which in periodically inputted from the computer of the processing institutions, and receiving information on subject vehicle verified as a vehicle in question from the portable communication device equipped in the surveillance vehicle through the communication network;

a main control part for controlling the building of the database for the information on vehicles in the question such as theft and search which is periodically inputted from the computers of the processing institutions and simultaneously controlling an transfer of the information to the portable communication device equipped in the surveillance vehicle through the communication network, and controlling into the database the storage of the information of the subject vehicle verified as a vehicle in the question which is received from the portable communication device equipped in the surveillance vehicle through the data communication part; and

the database for storing and updating the information on vehicles in various questions such as theft and search which is inputted from the processing institution computers according to the control of the main control part, and for storing the information on the subject vehicle verified as a vehicle in the question which is received from the portable communication device equipped in the surveillance vehicle.

6. The system as claimed in claim 4, wherein the surveillance part equipped in the surveillance vehicle determines whether a corresponding surveillance vehicle can deal with the subject vehicle if the subject vehicle is verified as a vehicle in question when verifying whether the subject vehicle is one in the question in comparison with the information on vehicles in the question which is stored in the database based on the license plate number of the subject vehicle which is extracted via the photographing of the camera, and, if the corresponding surveillance vehicle can not deal with the subject vehicle verified as a vehicle in question, transfers, for processing, the information on the subject vehicle verified as a vehicle in question to the computers of the processing institutions via the portable communication device connected to the surveillance part based on the data stored in the database.

7. A system for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, the subject vehicle being on the run or in parking or stopping, comprising:

the surveillance vehicle including;

a camera for photographing license plate information of the subject vehicle on the run or in parking or stopping,

a surveillance part for extracting the license plate number based on photographing data of the subject vehicle, and notifying a driver or a passenger in characters or by voice of result data on whether the subject vehicle is in the question which is received through a portable communication device from a server computer verifying whether the subject vehicle is one in question based on the extracted license plate number, and

the portable communication device for transferring the photographing data of the camera through a communication network to the server computer; and

the server computer for building a database for the information on vehicles in the question which is periodically provided from computers of processing institutions that control and manage vehicles through the communication network, extracting the license plate number of the subject vehicle based on the photographing data received from the surveillance vehicle through the communication network, verifying whether the subject vehicle is in question in comparison of the extracted license plate number of the subject vehicle with the information on vehicles in question which is stored in the database, and transferring result data as to whether the subject vehicle is in the question to the portable communication device equipped in the surveillance vehicle for a surveillance vehicle driver'"'"'s or a passenger'"'"'s verifications,

wherein the surveillance part equipped in the surveillance vehicle includes;

a key manipulation part for inputting a key manipulation signal of a driver or a passenger of the surveillance vehicle for recognition of the license plate number of the subject vehicle;

a photographing data input part for inputting the photographing data of the subject vehicle photographed via the camera;

a control part for controlling character and/or voice outputs of the result data on whether the subject vehicle is in question which is received from the server computer for a driver'"'"'s or a passenger'"'"'s verifications;

a display part for display the result data on whether the subject vehicle is in question which is received from the server computer through the portable communication device according to the control of the control part;

a voice output part for converting into voice the result data on whether the subject vehicle is one in question which is received from the server computer through the portable communication device according to the control of the control part for outputs through speakers; and

a communication interface connected for communications to the portable communication device equipped in the surveillance vehicle, and for outputting to the portable communication device the photographing data of the subject vehicle photographed by the camera according to the control of the control part, and outputting to the control part the result data as to whether the subject vehicle is in question which is inputted from the server computer through the portable communication device.

8. The system as claimed in claim 7, wherein the server computer includes:

a data communication part for periodically inputting through the communication network the information on vehicles in various questions such as theft and search from the computers of the processing institutions, receiving through the communication network the photographing data of the subject vehicle photographed by the camera from the portable communication device equipped in the surveillance vehicle, and transferring the result data as to whether the subject vehicle is one in the question which is inputted from a main control part to the portable communication device equipped in a corresponding surveillance vehicle;

the main control part for controlling the building of the database for the information on vehicles in various questions such as theft and search which is inputted through the data communication part from the computers of the processing institutions, controlling the extraction of the license plate number of the subject vehicle based on the photographing data of the subject vehicle which is received through the data communication part from the surveillance vehicle, verifying whether the subject vehicle is in the question in comparison of the license plate number of the corresponding subject vehicle with the information on vehicles which is stored in the database based on the extracted license plate number of the subject vehicle, and controlling an transfer of the result data as to whether the subject vehicle is one in question to the portable communication device equipped in the corresponding surveillance vehicle;

the database for storing and updating the information on vehicles in various questions such as theft and search which in inputted from the processing institution computers according to the control of the main control part; and

a license plate number recognition part for extracting the license plate number of the subject vehicle based on the photographing data of the subject vehicle which is received from the surveillance vehicle through the data communication part according to the control of the main control part.

9. The system as claimed in claim 7 or claim 8, wherein the server computer extracts the license plate number of the subject vehicle based on the photographing data of the subject vehicle which is received from the portable communication device equipped in the surveillance vehicle, determines whether the corresponding surveillance vehicle can deal with the subject vehicle if the subject vehicle is in question when verifying whether the subject vehicle has a problem in comparison of the information on vehicles in various question such as theft or search stored in the database, and transfers, for processing, the information on the subject vehicle verified as a vehicle in question to the computers of the processing institutions if the corresponding surveillance vehicle can not deal with the subject vehicle verified as a vehicle in question.

10. The system as claimed in claim 7, wherein the surveillance part equipped in the surveillance vehicle transfers, if the photographing data inclusive of the license plate information of the subject vehicle on the run or in parking or stopping which is photographed through manipulations of a driver or a passenger or through a movable(portable) camera bearer of the surveillance vehicle is downloaded, to the server computer through the communication network the photographing data of the corresponding subject vehicle which is downloaded.

11. A method for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, which is applied to an automatic license plate number recognition system, comprising steps of:

(1) recognizing the subject vehicle on the run or in parking or stopping which is located in a photographing range of a camera mounted to the surveillance vehicle, and photographing the subject vehicle inclusive of its license plate through the camera;

(2) extracting the license plate number of the subject vehicle based on photographing data of the subject vehicle photographed by the camera;

(3) transferring through a portable communication device to a server computer the license plate number of the subject vehicle which is extracted in the surveillance part equipped in the surveillance vehicle;

(4) inputting, if the server computer receives the license plate number of the subject vehicle from the surveillance vehicle, up-to-date information on vehicles in question from related processing institution computers based on whether a database provided for grasping whether the subject vehicle is in the question is valid, and updating the database;

(5) verifying by the server computer whether the subject vehicle has a problem in comparison with the information on vehicles in the question stored in the database based on the license plate number of the subject vehicle which is received from the surveillance vehicle;

(6) notifying, by the server computer, the surveillance vehicle that the subject vehicle is not one in question, if it is verified that the subject vehicle is not one in the question;

(7) determining, by the server computer, whether the surveillance vehicle can deal with the subject vehicle if it is verified that the subject vehicle is one in the question

(8) notifying, by the server computer, the surveillance vehicle that the subject vehicle is one in question to deal with the subject vehicle in the question, if the surveillance vehicle can deal with the subject vehicle in the question; and

(9) notifying, by the server computer, a related processing institution computer of the information on the subject vehicle to deal with the subject vehicle, if the surveillance vehicle can not deal with the subject vehicle in the question,

wherein the step (2) includes steps of;

(2-1) extracting a license plate region of the subject vehicle based on the photographing data inclusive of the license plate number of the subject vehicle photogaraphed by the camera;

(2-2) extracting individual character regions from the extracted license plate region;

(2-3) extracting characteristic vectors from the respective individual character regions extracted; and

(2-4) recognizing characters and numbers from the characteristic vectors extracted from the respective individual character regions to identify the license plate number of the subject vehicle.

12. The method as claimed in claim 11, wherein the step (2-1) includes steps of:

(2-1-1) acquiring an image for the extraction of the license plate region from the photographing data inclusive of the license plate information of the subject vehicle photographed by the camera;

(2-1-2) down-sampling the image acquired from the step (2-1-1) to lower a resolution thereof for alleviation of an image deterioration by camera movements;

(2-1-3) configuring an image pyramid having a different spatial resolution from the down-sampled image for a resolution selection suitable for the extraction of the license plate region;

(2-1-4) converting, after the configuration of the image pyramid having a different spatial resolution, a color level into a gray level in use of color information of the license plate, and then converting into a binary image through a suitable threshold value selection, producing a projection image in lengthwise and widthwise directions, and performing clustering to extract a rectangular region in use of the lengthwise and widthwise projection image and an aspect ratio of length and width of the license plate;

(2-1-5) determining whether a position and a size of the license plate in the clustering-performed image are correct and proceeding with the next step (2-2); and

(2-1-6) producing left, right, up, and down position information of the camera and a zoom control signal, if the position and size of the license plate region in the clustering-performed image are not correct, and controlling the camera by a control part of a surveillance part equipped in the surveillance vehicle.

13. The method as claimed in claim 11, wherein the step (2-2) includes steps of:

(2-2-1) converting into a gray level the license plate region extracted through the step (2-1);

(2-2-2) applying a horizontal histogram to the license plate region converted into the gray level for separation into upper and lower portions;

(2-2-3) applying a vertical histogram to the license plate region separated into the upper and lower portions according to the horizontal histogram application to extract individual characters existing in the license plate region; and

(2-2-4) digitizing through a proper threshold value selection the individual characters extracted through the horizontal and vertical histogram applications of the steps (2-2-2) and (2-2-3) and proceeding with the next step (2-3).

14. The method as claimed in claim 11, wherein the step (2-3) includes steps of:

(2-3-1) dividing in a vertical direction each individual character of the license plate region extracted through the step (2-2);

(2-3-2) dividing each individual character in a horizontal direction after the division of each individual character of the license plate region in the vertical direction;

(2-3-3) performing a 64-dimensional(8×

8) mapping after dividing respective individual characters of the license plate region in the horizontal and vertical directions; and

(2-3-4) normalizing values of the mapped respective individual characters, after the 64-dimensional(8×

8) mapping, to extract characteristic vectors.

15. The method for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, which is applied to an automatic license plate number recognition system, comprising steps of:

(A) recognizing the subject vehicle on the run or in parking or stopping which is located within a photographing range of a camera mounted to the surveillance vehicle, and photographing the subject vehicle inclusive of a license plate thereof through the camera;

(B) extracting a license plate number of the subject vehicle based on photographing data of the subject vehicle photographed by the camera;

(C) receiving up-to-date information on vehicles in question which is provided to a related processing institution computer from a server computer, after the extraction of the license plate number of the subject vehicle, according to whether a database provided for grasping whether the subject vehicle is in question is valid, and updating the database;

(D) comparing the information on vehicles in question which is stored in the database based on the license plate number of the subject vehicle extracted from a surveillance part equipped in a surveillance vehicle and verifying whether the subject vehicle has a problem;

(E) outputting characters or a voice, if the subject vehicle is not one in question, notifying from the surveillance part equipped in the surveillance vehicle that the subject vehicle is not one in question for driver'"'"'s or passenger'"'"'s identifications;

(F) determining whether the surveillance part equipped in the surveillance vehicle can deal with the subject vehicle if the subject vehicle is one in question;

(G) outputting characters or a voice, if the surveillance vehicle can deal with the subject vehicle in question, notifying from the surveillance part equipped in the surveillance vehicle that the subject vehicle is one in question to enable a driver or a passenger to deal with the subject vehicle in question; and

(H) notifying the related processing institution computer from the surveillance part equipped in the surveillance vehicle of information on the subject vehicle through a portable communication device, if the surveillance vehicle can not deal with the subject vehicle in question, to enable dealing with the subject vehicle in question

wherein the step (B) includes steps of;

(B-1) extracting the license plate region of the subject vehicle based on the photographing data inclusive of the license plate information of the subject vehicle photographed by the camera;

(B-2) extracting the individual character regions from the extracted license plate region;

(B-3) extracting characteristic vectors from the extracted respective individual character regions; and

(B-4) recognizing characters and numbers from the characteristic vectors extracted from the respective individual character regions to identify the license plate number of the subject vehicle.

16. The method as claimed in claim 15, wherein the step (B-1) includes steps of:

(B-1-1) acquiring an image for extracting the license plate region from the photographing data inclusive of the license plate information of the subject vehicle photographed by the camera;

(B-1-2) down-sampling the image acquired from the step (B-1-1) to lower a resolution thereof for alleviation of an image deterioration by movements of the camera;

(B-1-3) configuring an image pyramid having a different spatial resolution from the down-sampled image for a selection of a resolution suitable for the extraction of the license plate region;

(B-1-4) converting a color level into a gray level in use of color information of the license plate, after configuring the image pyramid having a different spatial resolution, and then converting into a binary image through a proper threshold value selection, producing a projection image in lengthwise and widthwise directions, and performing clustering to extract a rectangular region in use of the lengthwise/widthwise projection image and an aspect ratio of length and width of the license plate;

(B-1-5) determining whether a position and a size of the license plate region in the clustering-performed image are correct, and proceeding with the next step (B-2); and

(B-1-6) producing left, right, up, and down position information of the camera and a zoom control signal, if the position and size of the license plate region in the clustering-performed image are not correct, and controlling the camera by a control part of a surveillance part equipped in the surveillance vehicle.

17. The method as claimed in claim 15, wherein the step (B-2) includes steps of:

(B-2-1) converting into a gray level the license plate region extracted through the step (B-1);

(B-2-2) applying a horizontal histogram to the license plate region converted into the gray level for separation into upper and lower portions;

(B-2-3) applying a vertical histogram to the license plate region separated into the upper and lower portions according to the horizontal histogram application to extract individual characters existing in the license plate region; and

(B-2-4) digitizing through a proper threshold value selection the individual characters extracted through the horizontal and vertical histogram applications of the steps (B-2-2) and (B-2-3) and proceeding with the next step (B-3).

18. The method as claimed in claim 15, wherein the step (B-3) includes steps of:

(B-3-1) dividing in a vertical direction each individual character of the license plate region extracted through the step (B-2);

(B-3-2) dividing each individual character in a horizontal direction after the division of each individual character of the license plate region in the vertical direction;

(B-3-3) performing a 64-dimensional(8×

8) mapping after dividing respective individual characters of the license plate region in the horizontal and vertical directions; and

(B-3-4) normalizing values of the mapped respective individual characters, after the 64-dimensional(8×

8) mapping, to extract characteristic vectors.

19. The method for automatically recognizing a license plate number of a subject vehicle in use of a surveillance vehicle, which is applied to an automatic license plate number recognition system, comprising steps of:

(a) recognizing the subject vehicle on the run or in parking or stopping which is located within a photographing range of a camera mounted to the surveillance vehicle, and photographing the subject vehicle inclusive of a license plate thereof through the camera;

(b) transferring through the communication network to a server computer photographing data of the subject vehicle photographed by the camera;

(c) extracting a license plate number of the subject vehicle based on the photographing data if the server computer receives the photographing data of the subject vehicle from the surveillance vehicle;

(d) receiving, by the server computer, up-to-date information on vehicles in question from a related processing institution computer according to whether a database provided for grasping whether the subject vehicle is in question is valid, and updating the database;

(e) comparing, by the server computer, the information on vehicles in question which is stored in the database based on the license plate number of the subject vehicle and verifying whether the subject vehicle has a problem;

(f) notifying, by the server computer, the surveillance vehicle that the subject vehicle is not one in question, if the subject vehicle is not one in question;

(g) determining,by the server computer, whether the surveillance vehicle can deal with the subject vehicle if the subject vehicle is one in question;

(h) notifying, by the server computer, the surveillance vehicle that the subject vehicle is one in question, to enable the dealing with the subject vehicle in question, if the surveillance vehicle can deal with the subject vehicle in question; and

(i) notifying, by the server computer, the related processing institution computer of information on the subject vehicle, if the surveillance vehicle can not deal with the subject vehicle in question, to enable the dealing with the subject vehicle in question,

wherein the step (c) includes steos of;

(c-1) extracting a license olate reaion of the subject vehicle based on the photograghing data inclusive of license plate information of the subject vehicle photographed by the camera;

(c-2) extracting individual character regions from the extracted license plate region;

(c-3) extracting characteristic vectors from the extracted respective individual character regions; and

(c-4) recognizing characters and numbers from the characteristic vectors extracted from the respective individual character regions to identify the license plate number of the subject vehicle.

20. The method as claimed in claim 19, wherein the step (c-1) includes steps of:

(c-1-1) acquiring an image for extracting the license plate region from the photographing data inclusive of the license plate information of the subject vehicle photographed by the camera;

(c-1-2) down-sampling the image acquired from the step (c-1-1) to lower a resolution thereof for alleviation of an image deterioration by movements of the camera;

(c-1-3) configuring an image pyramid having a different spatial resolution from the down-sampled image for a selection of a resolution suitable for the extraction of the license plate region;

(c-1-4) converting a color level into a gray level in use of color information of the license plate, after configuring the image pyramid having a different spatial resolution, and then converting into a binary image through a proper threshold value selection, producing a projection image in lengthwise and widthwise directions, and performing clustering to extract a rectangular region in use of the lengthwise/widthwise projection image and an aspect ratio of length and width of the license plate;

(c-1-5) determining whether a position and a size of the license plate region in the clustering-performed image are correct, and proceeding with the next step (c-2); and

(c-1-6) producing left, right, up, and down position information of the camera and a zoom control signal, if the position and size of the license plate region in the clustering-performed image are not correct, and controlling the camera by a control part of a surveillance part equipped in the surveillance vehicle.

21. The method as claimed in claim 19, wherein the step (c-2) includes steps of:

(c-2-1) converting into a gray level the license plate region extracted through the step (c-1);

(c-2-2) applying a horizontal histogram to the license plate region converted into the gray level for separation into upper and lower portions;

(c-2-3) applying a vertical histogram to the license plate region separated into the upper and lower portions according to the horizontal histogram application to extract individual characters existing in the license plate region; and

(c-2-4) digitizing through a proper threshold value selection the individual characters extracted through the horizontal and vertical histogram applications of the steps (c-2-2) and (c-2-3) and proceeding with the next step (c-3).

22. The method as claimed in claim 19, wherein the step (c-3) includes steps of:

(c-3-1) dividing in a vertical direction each individual character of the license plate region extracted through the step (c-2);

(c-3-2) dividing each individual character in a horizontal direction after the division of each individual character of the license plate region in the vertical direction;

(c-3-3) performing a 64-dimensional(8×

8) mapping after dividing respective individual characters of the license plate region in the horizontal and vertical directions; and

(c-3-4) normalizing values of the mapped respective individual characters, after the 64-dimensional(8×

8) mapping, to extract characteristic vectors.