JPS61249199A - Vehicle identifier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device that automatically identifies a running automobile, which recognizes the characters on the license plate and also recognizes a part of the image other than the license plate. The present invention relates to a vehicle identification device that extracts vehicle types, table types, vehicle names, etc.

[Conventional technology]

Hitherto, no device of this type has been put to practical use.

[Problems to be solved]

To identify and specify a moving vehicle, it is sufficient to be able to recognize the characters in the vehicle's license plate.

However, the letters in the license plate of the vehicle being driven are #1.
Due to the effects of dust and weather, it is difficult to photograph images with sufficient contrast for recognition by machines.

Furthermore, in the case of a vehicle traveling at high speed, if the shutter speed is increased, the difference in gradation between the text and the background becomes small, making it difficult to obtain an image sufficient for machine recognition.

On the other hand, if the image of a moving vehicle is stored in such a high resolution that even the license plate can be read, there is a problem that it requires a large capacity memory and cannot be put to practical use.

[Means for solving problems]

The present invention solves the above-mentioned problems, and includes an image input means for photographing the front or rear side of a moving automobile, and an image of the number plate of the automobile from among the images obtained by the image input means. A character recognition means for recognizing characters, a partial image extraction section for cutting out a part of the image, and storage for storing together the image extracted by the partial image extraction section and the recognition result of the character recognition means. and display means for displaying the image in the storage means.

〔Example〕

Next, the embodiment will be described with reference to FIGS. 1 to 813.

The first diagram is a block diagram of a system of an embodiment of the vehicle identification device according to the present invention, FIG. 2 is a diagram showing the arrangement of characters on a vehicle license plate classified by m by the above device, and FIG. 3 is a partial diagram of a part of the above device. FIG. 2 is a block diagram showing a circuit of an image extraction section.

In FIG. 1, reference numeral 11 denotes a camera unit which is composed of a normal vidicon or COD camera and a Doppler type or loop coil type vehicle detector, and takes an image of, for example, the front side of a vehicle detected by the vehicle detector. The captured image signal is A/D converted and stored in the frame memory 12. Reference numeral 13 denotes a plate cutting section, which cuts out a number plate section from the image in the frame memory 12. Reference numeral 14 denotes a number plate character recognition unit which cuts out and recognizes characters from the nine number plate images cut out by the plate cutout unit 13. This recognition unit 14 is a normal optical character reader (OCR).
A method similar to that applied is used. 15
is a partial image extracting unit that extracts partial images other than the sinumbab plate from the image of the vehicle stored in the frame memory 12; The partial image position to be extracted is determined based on the obtained license plate position information and extracted from the image in the frame memory 12. Reference numeral 17 denotes a storage unit for storing the result of &I recognition by the character recognition unit 14 and the partial image extracted by the partial image extraction unit 15;
8 is configured as a readable memory. The control section 18 causes the display section 19 to display the results stored in the storage section 17 and controls the operation of the apparatus, and can be a general-purpose terminal.

The display section 19 is a cathode ray tube (CRT) that displays the data stored in the storage section 17, and is added to the control section 18 so that the data stored in the storage section 17 can be selectively displayed using a nine-control console. can.

Note that numeral 16 detects the inside of a traveling vehicle by an in-vehicle detection unit which includes a pressure sensor and the like arranged at a gate on the road.

As shown in FIG. 2, the plate cutting section 13 cuts out the number plate by utilizing the fact that the characters in the number plate 21 are arranged according to a predetermined arrangement. That is, a circumscribed rectangle of a black dot mass corresponding to the character size in the image (play) 21 is extracted from the photographed image, and the number plate 21 is discovered based on its size and arrangement. This method can apply the character extraction method used in normal OCR.

In FIG. 1, the partial images extracted by the partial image extracting unit 15 are parts such as the front grille, headlights, and bumper of a car, from which the type, table type, and name of the car can be determined from the shape thereof.

FIG. 3 shows nine details of the partial image extraction section 15. In the figure, numeral 31 is a calculation unit for a partial image area to be extracted from the image in the frame memory 32, and the inside detection unit 16 (1111
For example, the portions indicated by broken lines 32a to 32c in the frame memory 32 in FIG. 3 are determined from the in-vehicle information (see figure) and the plate position information obtained by the plate cutting section 13. That is, the starting and ending positions of the drawing image extraction position in the frame memory 32 are determined using the license plate 21 as a reference.

Reference numeral 33 denotes an address control unit for outputting m areas determined by the area calculation unit 31, and is constituted by an ordinary adder and a register. The picture image read out from the frame memory 32 by this address control unit 33 is the picture image read out from the frame memory 32 by the picture compressor 3.
The 0-side compressor 34 is an address generator that simply thins out every other pixel and stores it in the storage section 35.

〔Effect of the invention〕

As explained above, in order to identify a running vehicle, the present invention stores the recognition results of characters in the license plate as well as the characteristics of a part of the vehicle. If it cannot be recognized, display the car model,
By specifying the table type vehicle name and using it in conjunction with the recognition results, it is possible to drive without using a large capacity memory and to accurately identify nine vehicles.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a system of an embodiment of the vehicle identification device according to the present invention, FIG. 2 is a diagram showing the arrangement of characters on a vehicle license plate identified by the device, and FIG. 3 is a partial diagram of the device. FIG. 3 is a block diagram showing a circuit of an art relationship extraction section.

Claims (1)

[Claims] an image input means for capturing an image of the front or rear surface of a running vehicle; a character recognition means for recognizing characters on a license plate of the vehicle from among the images obtained by the image input means; and a character recognition means for recognizing a part of the image. A partial image extraction section for cutting out, a storage means for storing together the image extracted by the partial image extraction section and a recognition result of the character recognition means, and a display means for displaying the image in the storage means. A vehicle identification device characterized by: