Specifically, the image obtainer 1 extracts the vehicle information according to the vehicle image, and sends the vehicle information and the vehicle image to the second identifier 3. The vehicle information may include a license plate number, a color and a vehicle type. The second identifier 3 determines whether the vehicle information contained in the vehicle image is consistent with the standard vehicle information in the vehicle information base.

If at least one of the color and the vehicle type of the vehicle information contained in the vehicle image is not consistent with the corresponding at least one of the color and the vehicle type in the standard vehicle information of the same license plate number in the vehicle information base, the first identifier 2 further determines whether the license plate of the vehicle is tampered (i.e., performing step 25).

If the color and the vehicle type of the vehicle information contained in the vehicle image are both consistent with the color and the vehicle type in the standard vehicle information of the same license plate number in the vehicle information base, it means that the vehicle is a normal vehicle and the procedure is ended.

It should be noted that the vehicle information may be stored in the vehicle information base in the form of image, i.e., a vehicle image is stored in the vehicle information base. Correspondingly, when determining whether the extracted vehicle information is consistent with the standard vehicle information in the vehicle information base with the second identifier 3, the determination may be realized by directly matching the vehicle image to the standard vehicle image in the vehicle information base, i.e., directly matching the images. However, this manner of matching is low in speed and poor in precision.