Vehicle monitoring method, specific character pattern recognition device, and vehicle monitoring system

Abstract

In a vehicle monitoring method, recognition processing of a specific character pattern of a vehicle is performed by extracting a specific character pattern area from a taken image data. When the specific character pattern cannot be recognized, a compression range is judged as being a vehicle area clipped from the taken image data, and image data of the clipped area is compressed at a low compression ratio. When the specific character pattern is partially recognized, the compression range is judged as being the specific character pattern area clipped from the taken image data, and image data of the clipped area is compressed at the low compression ratio. When the specific character pattern is fully recognized, the compression range is judged as being the specific character pattern area clipped from the taken image data, and image data of the clipped area is compressed at a high compression ratio.

1 . A vehicle monitoring method comprising the steps of: 
 performing recognition processing of a specific character pattern of a vehicle by extracting a specific character pattern area from a taken image data in order to monitor the vehicle based on a recognized character pattern;    determining, when a result of the recognition processing indicates that the specific character pattern cannot be recognized, a compression range as being a vehicle area clipped from the taken image data, wherein image data of the clipped area is compressed at a predetermined low compression ratio to store or transmit the compressed image data;    determining, when the result indicates that the specific character pattern is partially recognized, the compression range as being the specific character pattern area clipped from the taken image data, wherein image data of the clipped area is compressed at the low compression ratio to store or transmit the compressed image data; and    determining, when the result indicates that the specific character pattern is fully recognized, the compression range as being the specific character pattern area from the taken image data, wherein image data of the clipped area is compressed at a predetermined high compression ratio to store or transmit the compressed image data.    
   
   
       2 . A specific character pattern recognition device comprising: 
 a recognition processing unit having a frame memory, a character recognition processing unit and an image processing unit, the frame memory temporarily storing an image data of a vehicle taken by an image-taking unit, the character recognition processing unit performing recognition processing of a specific character pattern of the vehicle, and the image processing unit clipping a vehicle area containing the whole vehicle from the taken image data and clipping a specific character pattern area from the vehicle area;    a compression range/ratio judging unit judging a compression range and a compression ratio based on a result of the recognition processing wherein, when the result of the recognition processing indicates that the specific character pattern cannot be recognized, the compression range and the compression ratio are judged as being the vehicle area and a predetermined low compression ratio, when the result indicates that the specific character pattern is partially recognized, the compression range and the compression ratio are judged as being the specific character pattern area and the low compression ratio, and when the result indicates that the specific character pattern is fully recognized, the compression range and the compression ratio are judged as being the specific character pattern area and a predetermined high compression ratio;    an image compression unit which is responsive to a judgment result of the compression range/ratio judging unit, the image compression unit clipping a corresponding area of image data for the compression range from the taken image data of the frame memory, and performing compression processing of the image data of the clipped area at the compression ratio; and    a transmitting/receiving unit transmitting the compressed image data from the image compression unit.    
   
   
       3 . The specific character pattern recognition device according to  claim 2  further comprising a data storing unit storing the compressed image data provided by the image compression unit, together with the result of the recognition processing of the specific character pattern of the vehicle.  
   
   
       4 . The specific character pattern recognition device according to  claim 3  further comprising a matching processing unit performing matching processing between an externally requested vehicle specific character pattern and the result of the recognition processing stored in the data storing unit, and, when a match occurs as a result of the matching processing, the compressed image data is read from the data storing unit and transmitted.  
   
   
       5 . A vehicle monitoring system including a plurality of specific character pattern recognition devices and a center which are connected through a communication line, each specific character pattern recognition device comprising: 
 a recognition processing unit performing recognition processing of a specific character pattern of a vehicle based on a taken image data, and the recognition processing unit clipping a vehicle area containing the whole vehicle from the taken image data, and clipping a specific character pattern area from the vehicle area;    a compression range/ratio judging unit judging a compression range and a compression ratio based on a result of the recognition processing wherein, when the result of the recognition processing indicates that the specific character pattern cannot be recognized, the compression range and the compression ratio are judged as being the vehicle area and a predetermined low compression ratio, when the result indicates that the specific character pattern is partially recognized, the compression range and the compression ratio are judged as being the specific character pattern area and the low compression ratio, and when the result indicates that the specific character pattern is fully recognized, the compression range and the compression ratio are judged as being the specific character pattern area and a predetermined high compression ratio;    an image compression unit which is responsive to a judgment result of the compression range/ratio judging unit, the image compression unit clipping a corresponding area of image data for the compression range from the taken image data, and performing compression processing of the image data of the clipped area at the compression ratio; and    a transmitting/receiving unit transmitting the compressed image data from the image compression unit, and    the center comprising:    a data management table in which the compressed image data received from each specific character pattern recognition device through the communication line are stored; and    a display unit displaying the compressed image data.