TWI505202B - License plate recognition method and system using the same - Google Patents

Description

License plate recognition method and system

The invention relates to a license plate recognition method and system.

In the traditional manual charging method, since the charging, the change or the sale, and the recovery of the ticket will consume a considerable amount of time, the toll booth area has always been the bottleneck of the expressway, and thus the overall speed of the expressway is reduced. In order to improve the above phenomenon, an electronic toll collection system using advanced communication and information technology has been developed.

One of the current electronic automatic charging methods is to use a specific short-range communication technology to use the microwave or wireless radio frequency tag to sense the deduction. It requires a passerby to install the device or the tag, and the sensing effect is easily affected by the external environment and is unstable.

Another common electronic automatic charging method is to use image license plate recognition. This method does not need to install equipment or labels by passers-by. However, it also affects the recognition effect by factors such as camera position, light source, weather, and license plate fouling. If the recognition effect is not good, it needs to be interpreted manually, which will greatly increase the cost. Therefore, how to effectively reduce the need for manual identification and the problem to be solved.

The main object of the present invention is to provide a license plate recognition method and system, which have lower cost, better recognition efficiency and correctness.

The license plate recognition method comprises the following steps: (A) acquiring the license plate image data of the vehicle by the image acquisition device; (B) transmitting the license plate image data to the server; (C) the server generating the recognition result according to the license plate image data; (D) the server According to the confidence index algorithm, the confidence index is analyzed for the recognition result to generate the confidence index; and (E) the server judges the validity of the recognition result according to the confidence index, wherein: (E-1) when the confidence index is less than the first set value , determining that the recognition result is invalid; (E-2) determining that the recognition result is valid when the confidence index is greater than the second set value; and (E-3) when the confidence index is greater than the first set value and less than the second set value, The license plate image data is manually identified to generate an auxiliary recognition result, wherein when the auxiliary recognition result is the same as the recognition result, the confidence index of the recognition result on the server is weighted to increase the value.

Step (E-3) is performed by the server to weight the confidence index of the recognition result to increase the value, which may be a modified confidence index algorithm, and the value of the confidence index generated when the server performs the confidence index analysis on the recognition result next time. improve. Step (E-3) is performed by the server to weight the confidence index of the recognition result to increase the value, which may be a data model used by modifying the confidence index algorithm, so that the server performs the confidence index analysis on the recognition result next time. The value of the confidence index has increased. Step (E-3) is performed by the server to weight the confidence index of the recognition result to increase the value, and may be a data database used by the modified confidence index algorithm to enable the server to perform a confidence index analysis on the recognition result next time. The value of the confidence index has increased.

The step (E-3) further includes: when the auxiliary recognition result is different from the recognition result, modifying the method for the server to generate the recognition result according to the license plate image data, so that the recognition result generated by the server next time is the same as the auxiliary recognition result. The manual identification of the license plate image data to generate the auxiliary recognition result as described in step (E-3) may be performed at the server. The manual identification of the license plate image data to generate the auxiliary recognition result in step (E-3) may be performed on a personal computer connected to the server information, and the auxiliary recognition result is transmitted to the server. The license plate recognition method further includes storing the recognition result.

The license plate recognition system includes: an image acquisition device and a server. The image acquisition device is configured to obtain license plate image data of the vehicle. The server is connected with the image acquisition device to receive the license plate image data transmitted by the image acquisition device; the recognition result is generated according to the license plate image data; the confidence index is analyzed according to the confidence index algorithm to generate a confidence index; and the confidence index is used to determine and identify The validity of the result, wherein: when the confidence index is less than the first set value, determining that the recognition result is invalid; when the confidence index is greater than the second set value, determining that the recognition result is valid; and when the confidence index is greater than the first set value and less than In the second set value, the license plate image data is manually identified to generate an auxiliary recognition result, wherein when the auxiliary recognition result is the same as the recognition result, the confidence index of the other result is weighted by the server to increase the value.

In another embodiment, the license plate recognition system includes an image capture device, a personal computer, and a server. The image acquisition device acquires license plate image data of the vehicle. The server is connected with the information of the personal computer and the image acquisition device, receives the license plate image data transmitted by the image acquisition device, generates the recognition result according to the license plate image data, and performs a confidence index analysis on the recognition result according to the confidence index algorithm to generate a confidence index; The index judges the validity of the recognition result, wherein: when the confidence index is less than the first set value, determining that the recognition result is invalid; when the confidence index is greater than the second set value, determining that the recognition result is valid; and when the confidence index is greater than the first setting When the value is less than the second set value, the license plate image data is manually recognized by the personal computer to generate the auxiliary recognition result, and the auxiliary recognition result is transmitted to the server, wherein when the auxiliary recognition result is the same as the recognition result, The server weights the confidence index of the recognition result to increase the value.

100‧‧‧Image acquisition device

300‧‧‧Server

500‧‧‧ PC

1010‧‧‧Steps

1030‧‧‧Steps

1050‧‧‧Steps

1070‧‧‧Steps

1090‧‧‧Steps

1091‧‧‧Steps

1093‧‧‧Steps

1095‧‧‧Steps

1100‧‧‧Steps

1 is a schematic flow chart of a preferred embodiment of a license plate recognition method according to the present invention; FIG. 2 is a schematic flow chart of different embodiments of a license plate recognition method according to the present invention; FIG. 3 is a schematic flowchart of different embodiments of a license plate recognition method according to the present invention; A schematic diagram of an embodiment of the invention of the license plate recognition system; and FIG. 5 is a schematic diagram of different embodiments of the license plate recognition system of the present invention.

The license plate recognition method and system of the present invention are preferably used in an electronic toll road system, but are not limited thereto. For example, it can be applied to vehicle access identification in a parking lot or a controlled area.

As shown in the preferred embodiment of FIG. 1, the media material sharing method of the present invention includes, for example, the following steps.

In step 1010, the image acquisition device acquires the license plate image data of the vehicle. Specifically, a digital camera is used as an image capturing device, and a license plate of a vehicle is used as a license plate image data. In different embodiments, the digital camera can also be used to record the vehicle, and then the license plate of the vehicle in the video screen is captured as the license plate image data. The image acquisition device is preferably, but not limited to, disposed at an electronic toll collection location of the expressway, and obtains license plate image data of the vehicle passing through the electronic toll collection location, as one of the basis for calculating the electronic toll fee.

In step 1030, the license plate image data is transmitted to the server. Specifically, as shown in FIG. 2, the image acquisition device is connected to the server through an internet, a wired telephone, a mobile phone, a data cable, a microwave, a radio, etc., so as to transmit the license plate image data to the server.

In step 1050, the server generates a recognition result based on the license plate image data. Specifically, the server has an image recognition module for recognizing license plate image data to generate a recognition result.

In step 1070, the server performs a confidence index analysis on the recognition result according to the confidence index algorithm to generate a confidence index.

Step 1090: The server determines the validity of the recognition result according to the confidence index, wherein: when the confidence index is less than the first set value, step 1091 determines that the recognition result is invalid.

When the confidence index is greater than the second set value, step 1093 determines that the recognition result is valid.

When the confidence index is greater than the first set value and less than the second set value, step 1095 is manually The manner is to identify the license plate image data to generate an auxiliary recognition result, wherein when the auxiliary recognition result is the same as the recognition result, the confidence index of the recognition result on the server is weighted to increase the value.

Specifically, in the method, when the confidence index is greater than the first set value and less than the second set value, it indicates that the server has a certain degree of reliability according to the license plate image data, and the license plate image data is manually identified. The auxiliary recognition result is generated, and then the confidence index of the recognition result identical to the auxiliary recognition result is weighted to increase the value, so that the next time the server performs the confidence index analysis on the recognition result, the value of the confidence index generated is increased, so that it is determined. It is "effective". In this way, not only can the recognition efficiency and correctness be improved, but also the need to identify the license plate image data by working means can be reduced, and the cost can be reduced.

In a different embodiment, step 1095, the server evaluates the confidence index of the recognition result to increase the value, and may be a modified confidence index algorithm, so that the next confidence index generated by the server when performing the confidence index analysis on the recognition result is generated. The value of the increase. Step 1095, the server may weight the confidence index of the recognition result to increase the value, or may modify the data model used by the confidence index algorithm to enable the server to generate a confidence index for the next time the confidence result is analyzed. The value is increased. In step 1095, the server evaluates the confidence index of the recognition result to increase the value, and may also modify the data database used by the confidence index algorithm to enable the server to generate a confidence index when the confidence index is analyzed for the next time. The value of the increase.

As shown in FIG. 2, step 1095 further includes: when the auxiliary recognition result is different from the recognition result, modifying the method for the server to generate the recognition result according to the license plate image data, so that the server generates the next recognition result and the auxiliary recognition result. the same. Further, when the auxiliary recognition result is different from the recognition result, it is necessary for the server to generate the recognition result according to the license plate image data, and the recognition efficiency is improved by modifying the method for generating the recognition result according to the license plate image data by the server. Correctness.

The manual identification of the license plate image data to generate the auxiliary recognition result in step 1095 may be performed at the server. Specifically, the license plate image data is displayed on a display directly connected to the server, and after being visually recognized by the operator, the result of the naked eye recognition is input to an input device (such as a keyboard, a mouse, a microphone, etc.) directly connected to the server.

The manual identification of the license plate image data to generate the auxiliary recognition result in step 1095 may be performed on a personal computer connected to the server information, and the auxiliary recognition result is transmitted to the server. Specifically, the license plate image data is displayed on a personal computer (including a desktop computer, a notebook computer, a tablet computer, a smart phone, etc.) connected to the server information, and is visually recognized by the operator, and then input to the naked eye on the personal computer. The result of the identification.

As shown in different embodiments of FIG. 3, the license plate recognition method of the present invention further includes a step 1100 of storing the recognition result. Specifically, it is preferable to store the identification result together with its confidence index and validity. However, in different embodiments, only the recognition results determined to be valid may be stored as needed.

As shown in FIG. 4, in the preferred embodiment, the license plate recognition system 800 of the present invention includes an image capture device 100 and a server 300. The image acquisition device 100 is configured to acquire license plate image data of the vehicle. The server 300 is connected to the image acquisition device to receive the license plate image data transmitted by the image acquisition device 100; the recognition result is generated according to the license plate image data; and the confidence index is analyzed according to the confidence index algorithm to generate a confidence index; according to the confidence index Determining the validity of the recognition result, wherein: when the confidence index is less than the first set value, determining that the recognition result is invalid; when the confidence index is greater than the second set value, determining that the recognition result is valid; and when the confidence index is greater than the first set value When the value is smaller than the second set value, the license plate image data is manually identified to generate an auxiliary recognition result. When the auxiliary recognition result is the same as the recognition result, the server 300 weights the confidence index of the other result to increase the value.

In another embodiment as shown in FIG. 5, the license plate recognition system 800 includes an image capture device 100, a personal computer 500, and a server 300. The image acquisition device 100 acquires license plate image data of the vehicle. The server 300 is connected to the personal computer 500 and the image capturing device 100, receives the license plate image data transmitted by the image capturing device 100, generates a recognition result according to the license plate image data, and performs a confidence index analysis on the recognition result to generate confidence according to the confidence index algorithm. Index; judge the validity of the recognition result according to the confidence index, wherein: when the confidence index is smaller than the first set value, the recognition result is invalid; when the confidence index is greater than the second set value, the determination result is valid; and when the confidence index When the value is greater than the first set value and less than the second set value, the personal computer 500 manually recognizes the license plate image data to generate an auxiliary recognition result, and transmits the auxiliary recognition result to the server 300, wherein the auxiliary recognition result is the same as the recognition result. At time, the confidence index of the recognition result is weighted by the server 300 to increase the value.

While the foregoing description of the preferred embodiments of the invention, the embodiments of the invention The spirit and scope of the principles of the invention. Modifications of many forms, structures, arrangements, ratios, materials, components and components can be made by those skilled in the art to which the invention pertains. Therefore, the embodiments disclosed herein are to be considered as illustrative and not restrictive. The scope of the present invention is defined by the scope of the appended claims, and the legal equivalents thereof are not limited to the foregoing description.

Claims (10)

A license plate recognition method, comprising the steps of: (A) acquiring image data of a license plate of a vehicle in an image acquisition device; (B) transmitting the license plate image data to a server; (C) the server according to the license plate image The data generates a recognition result; (D) the server performs a confidence index analysis on the recognition result according to a confidence index algorithm to generate a confidence index; and (E) the server determines the recognition result according to the confidence index Validity, wherein: (E-1) when the confidence index is less than a first set value, determining that the recognition result is invalid; (E-2) determining the recognition result when the confidence index is greater than a second set value And (E-3) when the confidence index is greater than the first set value and less than the second set value, manually identifying the license plate image data to generate an auxiliary recognition result, wherein the auxiliary recognition result is When the recognition result is the same, the confidence index of the recognition result is weighted by the server to increase the value. The license plate recognition method according to claim 1, wherein in step (E-3), the server weights the confidence index of the recognition result to increase the value, and the confidence index algorithm is modified to make the server next time. When the confidence index is analyzed for the recognition result, the value of the confidence index generated is increased. The method for identifying a license plate according to claim 1, wherein the step (E-3), wherein the server weights the confidence index of the recognition result to increase the value, is a data model used by modifying the confidence index algorithm, so that The next time the server performs the confidence index analysis on the recognition result, the value of the confidence index generated increases. The method for identifying a license plate according to claim 1, wherein the step (E-3) of the server is used to weight the confidence index of the recognition result to increase the value, and the data database used by the confidence index algorithm is modified. The next time the server performs the confidence index analysis on the recognition result, the value of the confidence index generated increases. The method for identifying a license plate according to claim 1, wherein the step (E-3) further comprises: when the auxiliary recognition result is different from the recognition result, modifying a method for the server to generate the recognition result according to the license plate image data, so that the method The recognition result generated by the server next time is the same as the auxiliary recognition result. The license plate recognition method according to claim 1, wherein the step (E-3) manually identifying the license plate image data to generate the auxiliary recognition result is performed at the server. The license plate recognition method according to claim 1, wherein the step (E-3) manually identifying the license plate image data to generate the auxiliary recognition result is performed on a personal computer connected to the server information, and The auxiliary recognition result is transmitted to the server. The license plate recognition method according to claim 1, further comprising storing the recognition result A license plate recognition system according to any one of claims 1 to 6, comprising: an image acquisition device for acquiring license plate image data of a vehicle; and a server connected to the image acquisition device for receiving the image Obtaining the license plate image data transmitted by the device; generating a recognition result according to the license plate image data; performing a confidence index analysis on the recognition result according to a confidence index algorithm to generate a confidence index; and determining the recognition result according to the confidence index Validity, wherein: when the confidence index is less than a first set value, determining that the recognition result is invalid; when the confidence index is greater than a second set value, determining that the recognition result is valid; and when the confidence index is greater than one When the first set value is less than a second set value, the license plate image data is manually identified to generate an auxiliary recognition result, wherein when the auxiliary recognition result is the same as the recognition result, the server recognizes the recognition result The confidence index is weighted to increase the value. A license plate recognition system according to any one of claims 1 to 5 or 7, comprising: an image acquisition device for acquiring license plate image data of a vehicle; a personal computer; and a server, the personal computer and the image Acquiring a device information connection, receiving the license plate image data transmitted by the image acquisition device; generating a recognition result according to the license plate image data; performing a confidence index analysis on the recognition result according to a confidence index algorithm to generate a confidence index; The confidence index judges the validity of the recognition result, wherein: When the confidence index is less than a first set value, determining that the recognition result is invalid; when the confidence index is greater than a second set value, determining that the recognition result is valid; and when the confidence index is greater than a first set value and When the value is less than a second set value, the license plate image data is manually recognized by the personal computer to generate an auxiliary recognition result, and the auxiliary recognition result is transmitted to the server, wherein the auxiliary recognition result is the same as the recognition result. At the time, the confidence index of the recognition result is weighted by the server to increase the value.