JP7104123B2 - Camera installation support program, camera installation support method and camera installation support system - Google Patents

Description

The present disclosure relates to a camera installation support program, a camera installation support method, and a camera installation support system.

Patent Document 1 describes an image processing device capable of detecting a user near the door of a car using an image including the inside of the car and the landing taken by a camera, and an image processing device connected to the image processing device by an administrator. An elevator system including an operable administrator terminal is disclosed. The elevator system acquires an image taken from the camera with a marker that can distinguish the floor of the car from the floor of the landing, and displays the recognition result of recognizing the marker from the acquired image. , Detects the deviation of the camera mounting position based on the recognized marker position based on the administrator's operation on the displayed recognition result.

Japanese Patent Application No. 2019-53670

The elevator system of Patent Document 1 uses a camera to image the vicinity of the car door and detects a user moving toward the elevator. Here, in recent years, there is a camera that captures and detects a license plate of a stopped or running vehicle or the like. However, when trying to detect the license plate of a vehicle with a camera using the configuration of Patent Document 1, the traveling position of the vehicle with respect to the width of the road, the mounting position or mounting angle of the license plate, or the shape of the road (for example, the inclination angle). ) Etc., the appearance of the license plate differs in the actual captured image, so there is a problem that it is difficult to know whether the camera is properly installed. In such camera installation work, there is a desire for workers to know whether or not a camera suitable for license plate detection can be installed during actual operation.

The present disclosure has been devised in view of the above-mentioned conventional circumstances, and is a camera installation support program, a camera installation support method, and a camera that support the installation of a camera and improve the recognition accuracy of the recognition process using the captured image. The purpose is to provide an installation support system.

The present disclosure is a preset detection from each of a plurality of captured images captured by the camera on a terminal device which is a computer communicably connected to a camera that captures at least one vehicle. A step of detecting each of the vehicle license plates reflected in the area, a step of determining whether or not the detection result satisfies the achievement condition of at least one specified index, and a background image of the imaging region captured by the camera. In addition, a plate position drawing image plotted for each number plate so that the two points indicating the detected positions of the license plates and the determination result of whether or not the achievement conditions are satisfied at the positions can be clearly identified. A camera installation support program is provided to realize the steps of generating and outputting the image.

Further, the present disclosure is a camera installation support method of a camera installation support system in which a camera and a terminal device are communicably connected, and detection is set in advance from each of a plurality of captured images captured by the camera. Each of the license plates of at least one vehicle reflected in the area is detected, and it is determined whether or not the detection result satisfies the achievement condition of at least one specified index, and the background image of the imaging area captured by the camera is used. , The plate position drawing image plotted for each license plate so that the two points indicating the detected positions of the license plates and the determination result of whether or not the achievement conditions are satisfied at those positions can be clearly identified. Provide a camera installation support method that generates and outputs.

Further, the present disclosure is a camera installation support system including a camera and a terminal device communicably connected to the camera, wherein the camera captures each of a plurality of captured images. The terminal device detects at least one vehicle number plate from a preset detection area among the plurality of captured images, and the detection result is specified as an achievement condition of at least one index. It is determined whether or not the conditions are satisfied, and the background image of the imaging region imaged by the camera includes two points indicating the positions of the number plates detected, and whether or not the achievement conditions are satisfied at those positions. Provided is a camera installation support system that generates and outputs a plate position drawing image plotted for each number plate so as to be able to identify the determination result of.

According to the present disclosure, it is possible to support the installation of a camera and improve the recognition accuracy of the recognition process using the captured image.

A block diagram showing an example of the internal configuration of the camera installation support system according to the first embodiment. A flowchart showing an example of an operation procedure of the terminal device according to the first embodiment. A diagram illustrating an example of license plate plate width, plate tilt, and detection area. A table showing examples of achievement conditions and non-achievement conditions for each index A table showing an example of advice information Diagram showing an example of the number recognition result screen Diagram showing an example of the plate position confirmation screen before and after camera installation support Diagram showing an example of the plate position confirmation screen before and after camera installation support Diagram showing an example of the plate position confirmation screen before and after camera installation support The figure which shows an example of the plate position confirmation screen when each of a plurality of detection areas is set.

Hereinafter, each embodiment in which the camera installation support program, the camera installation support method, and the configuration and operation of the camera installation support system according to the present disclosure are specifically disclosed will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
FIG. 1 is a block diagram showing an example of the internal configuration of the camera installation support system 100 according to the first embodiment. The camera installation support system 100 is a system for supporting the installation of the camera C1 desired by the user, for example, when the camera C1 is installed in a predetermined place and environment. The camera installation support system 100 executes recognition processing for, for example, a vehicle number plate as an image capture target based on the image captured by the camera C1, and adjusts the camera installation position or setting based on the recognition result. Generates and outputs adjustment advice information for. The camera installation support system 100 includes a camera C1, a network NW, and a terminal device P1.

The camera C1 according to the first embodiment is, for example, a surveillance camera, but the use and type of the camera are not limited to this. Further, the camera installation support system 100 according to the first embodiment shows, as an example, an example of detecting and recognizing a vehicle license plate, but the present invention is not limited to this. For example, the camera installation support system 100 may detect, for example, a vehicle, a two-wheeled vehicle, a person, or the like, and recognize these characteristics (for example, license plate, number, vehicle type, color, gender, clothes, age, etc.).

The camera C1 is installed at a position where the image pickup target can be captured by the user, detects the image pickup target from within a preset detection area of the captured image, and executes the recognition process. The camera C1 associates the captured image with the recognition result and transmits the captured image to the terminal device P1 at predetermined intervals (for example, 100 ms, 200 ms, etc.). The camera C1 includes a communication unit 10, a processor 11, a memory 12, and an imaging unit 13.

The communication unit 10 is configured by using a communication interface circuit for transmitting / receiving data or information to / from the terminal device P1 via the network NW. The communication unit 10 associates the captured image captured by the imaging unit 13 with the recognition result generated by the processor 11 and transmits the image to the terminal device P1 through the wireless communication network or the wired communication network.

The processor 11 is configured by using, for example, a CPU (Central Processing unit) or an FPGA (Field Programmable Gate Array), and performs various processes and controls in cooperation with the memory 12. Specifically, the processor 11 refers to the program and data held in the memory 12 and executes the program to realize the functions of each part.

The processor 11 acquires each of the captured images captured by the imaging unit 13 and executes each process for the imaging target (in the example shown in the first embodiment, the license plate NP of the vehicle) reflected in the captured image. Hereinafter, each recognition process executed by the processor 11 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of the plate width ΔX, the plate inclination θ, and the detection area AR1 of the license plate NP.

The processor 11 assigns a frame line indicating a set detection area AR1 area (for example, a detection area AR2 area shown in FIG. 7) to each of the captured images captured at predetermined intervals (for example, 100 ms, 200 ms, etc.). The solid line frame shown) is superimposed on the captured image to generate a captured image with a detection area, and the license plate NP displayed in the detection area AR1 is detected. Here, the processor 11 not only has a frame line indicating the area of the detection area AR1, but also an image captured with a detection area in which broken lines indicating the respective areas of the first detection zone AR11 and the second detection zone AR12 are superimposed. May be generated.

The processor 11 recognizes and acquires each character information based on the license plate NP detected from the detection area AR1. Each character information referred to here is information about the vehicle shown on the license plate NP, and is, for example, land transportation branch office information, vehicle type information, type information, serial number (vehicle number) information, and the like. Needless to say, the above-mentioned character information is an example and is not limited to this. Further, the information recognized by the processor 11 may be arbitrarily set by the image pickup target of the camera C1. For example, when the image pickup target is a person, it may be height, clothes, clothes color, age, gender, or the like. ..

Further, the processor 11 assigns a vehicle ID that makes the vehicle identifiable to the license plate NP determined to be the same vehicle based on each of these character information, and stores the image in association with the captured image. When a plurality of detection areas are set and license plates of a plurality of vehicles are detected from one captured image, a vehicle ID is associated with each license plate detected from each detection area. Further, the processor 11 determines the position where the license plate NP is detected in the information of the detection area and the detection zone (for example, in either the first detection zone AR11 or the second detection zone AR12 in the detection area AR1 shown in FIG. The information of (is there) is saved in association with the captured image for each license plate.

Further, the processor 11 measures the coordinates of the two vertices PS1 and PS2 facing each other among the four vertices of the detected license plate NP. Here, in the example shown in FIG. 2, the processor 11 measures the coordinates (X1, Y1) of the upper left vertex PS1 and the coordinates (X2, Y2) of the lower right vertex PS2 of the license plate NP. Based on the respective coordinates of the two measured vertices PS1 and PS2, the processor 11 has the coordinates of the midpoint PS3 (X3, Y3) and the coordinates of the midpoint PS4 (X4, Y4) in the lateral direction of the number plate NP. And are calculated respectively.

The processor 11 determines whether or not the license plate NP is included in the detection area AR1 set by the user based on the calculated coordinates of the two midpoints PS3 and PS4. Specifically, the processor 11 determines whether or not the coordinates of the two midpoints PS3 and PS4 are within the detection area AR1. Further, the processor 11 determines whether the license plate NP is detected in the first detection zone AR11 or the second detection zone AR12 in the detection area AR1. The first detection zone AR11 referred to here is a region having a width ΔX2 centered on a midpoint in the width direction (left-right direction of the paper surface) of the detection area AR1 set by the user, and has a plate width ΔX as an index described later. It is equal to the minimum value set as the achievement condition (for example, 120 pixels). The second detection zone AR12 is two regions obtained by removing the width ΔX2 of the first detection zone AR11 from the width ΔX1 of the detection area AR1. The first detection zone AR11 is an area adjacent to the two second detection zones AR12 and sandwiched between the two second detection zones AR12.

The processor 11 calculates the plate width ΔX of the license plate NP and the plate inclination θ based on the respective coordinates of the two calculated midpoints PS3 and PS4. (Formula 1) is a formula for calculating the plate width ΔX. The plate width ΔX indicates the number of pixels between the coordinates of the midpoint PS3 (X3, Y3) and the coordinates of the midpoint PS4 (X4, Y4). Further, (Formula 2) is a formula for calculating the inclination θ of the plate.

Further, the processor 11 has the highest luminance value (that is, the luminance value of the pixels in the background portion other than the character portion of the license plate NP) and the lowest luminance value (that is, the luminance value of the pixels in the background portion other than the character portion of the license plate NP) among the pixels included in the detected license plate NP region. The brightness value of the pixel of the character part of the license plate NP) is calculated. The processor 11 may calculate the luminance difference ΔL indicating the difference between the maximum luminance value and the minimum luminance value.

The camera C1 stores (saves) the captured image with the detection area in association with each recognition result. The recognition results referred to here are, for example, each character information, vehicle ID information, detection area information, detection zone information, coordinates of each of the two midpoints PS3 and PS4, plate width ΔX, plate inclination θ, and so on. It is needless to say that the maximum brightness value, the minimum brightness value, and the like are not limited thereto.

The processor 11 associates the stored (saved) captured image with the detection area with each recognition result based on the control command for requesting the start of acquisition of the captured image and the recognition result transmitted from the terminal device P1. Then, it is transmitted to the terminal device P1. The captured images and the recognition results for a predetermined period may be stored in the memory 12, and data communication is possible with a storage medium (not shown) such as an HDD (Hard Disk Drive) or the camera C1. It may be an external storage medium (not shown) such as an SD card (registered trademark) connected to the device.

The memory 12 includes, for example, a RAM (Random Access Memory) as a work memory used when executing each process of the processor 11 and a ROM (Read Only Memory) for storing a program and data defining the operation of the processor 11. Have. Data or information generated or acquired by the processor 11 is temporarily stored in the RAM. A program that defines the operation of the processor 11 is written in the ROM. The memory 12 stores the product number information of the camera C1, the information of various setting parameters (for example, the gain level, the bright part correction, the dark part correction, etc.), the information of the detection area, and the like.

The image pickup unit 13 includes at least a lens (not shown) and an image sensor (not shown). The image sensor is, for example, a solid-state image sensor such as a CCD (Charged-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor), and converts an optical image imaged on an imaging surface into an electric signal. The imaging unit 13 outputs the captured image to the processor 11.

The illumination unit 14 is, for example, an illumination for irradiating the imaging region of the camera C1 with light, and is realized by, for example, an IR-LED (Light Mission Diode), an LED, or the like. The illumination unit 14 is controlled by the processor 11 to execute lighting or extinguishing control and adjust the amount (brightness) of the emitted light.

The terminal device P1 includes an interface (for example, a keyboard, a mouse, a touch panel display, etc.) capable of accepting a user's input operation as an input unit 23. The terminal device P1 is communicably connected to the camera C1 via the network NW, and transmits a signal generated based on a user input operation to the server S1 via the network NW. Further, the terminal device P1 displays the composite image received from the server S1 via the network NW on the monitor 24. The terminal device P1 includes a communication unit 20, a processor 21, a memory 22, an input unit 23, a monitor 24, and an HDD 25.

The communication unit 20 is configured by using a communication interface circuit for transmitting / receiving data or information to / from the camera C1 via the network NW. The communication unit 20 transmits a control signal based on the user's input operation generated by the processor 21 to the camera C1 through the wireless communication network or the wired communication network, and acquires the captured image transmitted from the camera C1.

The processor 21 is configured by using, for example, a CPU or an FPGA, and cooperates with the memory 22 to perform various processes and controls. Specifically, the processor 21 refers to the program and data held in the memory 22 and executes the program to realize the functions of each part.

The memory 22 includes, for example, a RAM as a work memory used when executing each process of the processor 21, and a ROM for storing a program and data defining the operation of the processor 21. Data or information generated or acquired by the processor 21 is temporarily stored in the RAM. A program that defines the operation of the processor 21 is written in the ROM. The memory 22 stores various data transmitted from the camera C1, information on the set detection area, and the like. The various data referred to here are the acquisition start time of the captured image, the acquisition end time of the captured image, the IP address of the camera C1, the product number information of the camera C1, the captured image on which the set detection area is superimposed, and the recognition result. The position (coordinates) information of the recognition target, the project name as the save destination, etc.

The input unit 23 is, for example, a user interface for detecting an input operation of a user, and is configured by using a mouse, a keyboard, a touch panel, or the like. Based on the user's input operation, the input unit 23 receives settings related to the camera C1, settings related to detection and recognition processing, etc., converts them into signals, and outputs them to the processor 21.

The monitor 24 is configured by using a display such as an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence).

The HDD 25 records various data transmitted from the camera C1, a recognition result executed by the processor 21, adjustment advice information regarding the installation and setting of the camera C1, and the like.

The network NW is communicably connected to the terminal device P1 and the camera C1 by a wireless communication network or a wired communication network. The wireless communication network referred to here is, for example, a wireless LAN (Local Area Network), a wireless WAN (Wide Area NetWork), 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), or Wi-Fi (Wi-Fi (5th generation mobile communication system)). It is provided in accordance with wireless communication standards such as (registered trademark).

Next, the operation procedure of the terminal device P1 will be described with reference to FIG. FIG. 2 is a flowchart showing an example of an operation procedure of the terminal device P1 according to the first embodiment.

The terminal device P1 transmits a control signal for requesting the captured image for a predetermined period in which the recognition result is associated with the camera C1 based on the user operation requesting the start of acquisition of the captured image and the recognition result of the camera C1. The terminal device P1 stores the start date and time indicating the timing of accepting the user operation requesting the start of acquisition of the captured image and the recognition result in association with the IP (Internet Protocol) address of the camera C1 as the target IP (St1). .. The information to be saved is not limited to this, and may be, for example, a product number that can identify the camera C1, the name of the folder set as the save destination, the project name input by the user, or the like.

The terminal device P1 acquires each of the captured images (that is, captured images with a detection area) for a predetermined period transmitted from the camera C1 and associates them with various information such as the start date and time or the IP address of the camera C1. It is saved in the memory 12 (St2). Further, the terminal device P1 acquires each recognition result associated with each of the captured images and stores the recognition result in the memory 12 (St3).

The terminal device P1 is associated with the acquisition and storage of each of the captured images for a predetermined period and the captured images based on the user operation requesting the end of acquisition of the captured image and the recognition result transmitted from the camera C1. The end date and time indicating the timing at which the acquisition and storage of each recognition result is completed and the user operation requesting the acquisition and end of the captured image and the recognition result is received is stored in the memory 12 in association with the start date and time, the IP address, and the like. (St4).

端末装置Ｐ１は、認識結果の表示を要求するユーザ操作に基づいて、ステップＳｔ１～ステップＳｔ４の処理においてメモリ１２に保存された各種データ（具体的に、開始日時、ＩＰアドレス、終了日時、開始日時All captured images acquired during the period from 1 to the end date and time, each of the recognition results, etc.) are copied and saved in the HDD 25 (St5).

The terminal device P1 executes a time-overlapping captured image deletion process, image separation process, and the like from each of the plurality of captured images copied to the HDD 25, and cuts out the detected license plate NP from the plurality of plate images. (Plate images NP1, NP2, NP3, NP4 included in the number recognition result screen SC0 shown in FIG. 5) are generated. The terminal device P1 generates display recognition result data DT0 (see FIG. 5) based on each of the generated plurality of plate images and each recognition result (St6).

Further, the terminal device P1 executes an analysis process of installing or setting the camera C1 based on each recognition result (St7). Specifically, the terminal device P1 has each analysis item such as the number of pixels appropriate rate, the plate tilt appropriate rate, the brightness difference appropriate rate, the detection area inner frame rate, the serial number matching rate, and the number of recognition results based on each recognition result. Executes the analysis process of. It should be noted that each analysis item referred to here is, for example, an item for determining whether or not the camera C1 for imaging the license plate NP of the vehicle to be imaged has been installed or set, and is limited to the above-mentioned items. It doesn't have to be.

The terminal device P1 generates a number recognition result screen SC0 (see FIG. 6) based on the analysis results of a plurality of analysis items (St8), outputs it to the monitor 24, and displays it. Further, the terminal device P1 generates advice information based on the analysis results of a plurality of analysis items for each set detection area, and corresponds to the analysis result display area DT17 (see FIG. 6) of the number recognition result screen SC0. Outputs advice information for each detection area (St9).

When the plate position confirmation button BT2 included in the number recognition result screen SC0 is pressed (selected) by the user operation, the terminal device P1 generates a plate position drawing image (see FIGS. 7 to 10) and monitors 24. It is output to and displayed (St10).

Here, with reference to FIGS. 4 and 5, the processes of steps St7 to St9 shown in FIG. 2 (that is, analysis processing of a plurality of analysis items and generation processing of advice information executed by the terminal device P1) will be described. do. FIG. 4 is a table TB1 showing an example of the achievement condition and the non-achievement condition of each analysis item of the license plate NP. FIG. 5 is a table TB2 showing an example of advice information. Needless to say, each index, each achievement condition, and each non-achievement condition shown in the table TB1 is an example, and is not limited thereto. Similarly, it goes without saying that the example of the advice information corresponding to each analysis item shown in the table TB2 is an example and is not limited to this. Further, the advice information corresponding to each analysis item will be described with reference to Table TB2 for an example generated when it is determined that the achievement condition of each analysis item has not been achieved, but the achievement condition of each analysis item has been achieved. If it is determined, notification information may be generated to notify the user that the achievement condition of this analysis item has been achieved.

(Analysis processing of the appropriate number of pixels)
The terminal device P1 analyzes the pixel number appropriateness rate based on the plate width ΔX reflected in the detection area of the camera C1. The terminal device P1 determines whether or not the plate width ΔX satisfies the achievement condition 480 pixels ≧ ΔX ≧ 120 pixels for all the license plate NPs detected from each detection area of all the captured images. When the terminal device P1 determines that the plate width ΔX satisfies the achievement condition, the width (that is, the number of pixels) of the imaged license plate NP is the number of pixels more suitable for recognizing each character information, or the camera. It is determined that the mounting position and mounting angle of C1 (that is, the depression angle or swing angle of the camera C1) are mounting angles that can recognize each character information of the license plate NP. On the other hand, when the terminal device P1 determines that the plate width ΔX does not satisfy the achievement condition (that is, the unachieved condition is satisfied), the current zoom magnification of the camera C1 is set, or the mounting position or mounting of the camera C1. It is necessary to judge that the angle needs to be adjusted and increase the number of angles of the number plate NP displayed in each detection area such as "Please adjust the zoom of the camera so that the plate width in the detection area becomes large." It is necessary to adjust the mounting position or mounting angle of the camera C1 such as advice information that there is, or "Please adjust the mounting position (distance / swing angle) of the camera so that the plate width in the detection area becomes large." Generate advice information to the effect that.

Further, the terminal device P1 calculates (analyzes) the ratio at which the plate width ΔX that satisfies the achievement condition is measured among all the license plate NPs to which the same vehicle ID is given as the pixel number appropriate rate in this vehicle ID. do. Further, when the terminal device P1 receives the analysis request of the pixel number appropriate rate of all the vehicle IDs by the user operation, the plate width ΔX that satisfies the achievement condition among the license plate NPs of all the vehicle IDs is measured. The ratio is calculated (analyzed) as the pixel number appropriate ratio of all vehicle IDs. Thereby, the terminal device P1 can determine whether or not the zoom magnification, the mounting position (that is, the imaging distance), or the mounting angle of the camera C1 is more appropriate based on the pixel number appropriateness ratio.

(Analysis processing of tilt appropriateness rate)
Further, the terminal device P1 analyzes the plate inclination appropriateness rate based on the plate inclination θ reflected in each detection area of the camera C1. The terminal device P1 determines whether or not the plate inclination θ satisfies the achievement condition “θ <11 °” for all the license plate NPs detected from each detection area of all the captured images. When the terminal device P1 determines that the plate inclination θ satisfies the achievement condition, the mounting angle of the camera C1 (that is, the depression angle or the swing angle of the camera C1) can recognize each character information of the number plate NP. Is determined to be. On the other hand, when the terminal device P1 determines that the plate inclination θ does not satisfy the achievement condition (that is, satisfies the unachieved condition “θ ≧ 11 °”), the mounting angle of the camera C1 (that is, the depression angle of the camera C1). Or, it is judged that the swing angle) is large, and it is necessary to adjust the depression angle or mounting angle of the camera C1 such as "Please adjust the depression angle and swing angle of the camera so that the plate angle in the detection area becomes smaller." Generate advice information for.

The terminal device P1 calculates (analyzes) the ratio of the measured plate inclination θ that satisfies the achievement condition among all the license plate NPs to which the same vehicle ID is given as the plate inclination appropriate rate for this vehicle ID. Further, when the terminal device P1 receives the analysis request of the plate inclination appropriateness rate of all the vehicle IDs recognized in all the captured images by the user operation, the achievement condition among the license plate NPs of all the vehicle IDs. The ratio at which the plate inclination θ satisfying the condition is measured is calculated (analyzed) as the plate inclination appropriateness rate of all vehicle IDs. Thereby, the terminal device P1 can determine whether or not the mounting angle of the camera C1 is more appropriate based on the calculated plate tilt appropriateness rate.

(Analysis processing of luminance difference appropriate rate)
Further, the terminal device P1 analyzes the luminance difference appropriateness rate based on the luminance difference ΔL of the license plate NP reflected in each detection area of the camera C1. The terminal device P1 calculates the luminance difference ΔL, which is the difference between the maximum luminance value and the minimum luminance value of all the license plate NPs detected from each detection area in all the captured images, and this luminance difference ΔL is the achievement condition “ It is determined whether or not “ΔL ≧ 60” is satisfied. When the terminal device P1 determines that the brightness difference ΔL satisfies the achievement condition, the setting of the gain level or the brightness correction (that is, the dark part correction and the bright part correction) of the camera C1 or the setting of the illumination unit 14 is the number. It is determined that each character information of the plate NP is set to be recognizable. On the other hand, when the terminal device P1 determines that the brightness difference ΔL does not satisfy the achievement condition (that is, satisfies the unachieved condition “ΔL <60”), the gain level or brightness correction of the camera C1 is set, or It is determined that the brightness (illuminance) of the lighting unit 14 needs to be adjusted, and advice information is generated.

Here, when the brightness difference ΔL does not satisfy the achievement condition, the terminal device P1 generates more detailed advice information based on the maximum and minimum brightness values of the license plate NP or the imaging time of the license plate NP. You can. Hereinafter, an example of generating advice information based on the maximum and minimum brightness values of the license plate NP or the imaging time of the license plate NP will be described.

First, when the luminance difference ΔL does not satisfy the achievement condition, the terminal device P1 determines whether the captured image is blacked out or overexposed based on the maximum luminance value and the minimum luminance value. .. Further, the terminal device P1 determines whether the time zone in which these license plate NPs are imaged is daytime or nighttime based on the information of the imaging times of the plurality of captured images.

When the terminal device P1 determines that the captured image is blacked out and the captured time zone is daytime, "corrects the dark area so that the difference between the maximum brightness and the minimum brightness of the plate becomes large." Generate advice information to the effect that adjustment to raise the dark area correction of the camera C1 is necessary, such as "Please raise and adjust." When the terminal device P1 determines that the captured image is blacked out and the captured time zone is nighttime, "the gain level is set so that the difference between the maximum brightness and the minimum brightness of the plate becomes large." Advice information that it is necessary to adjust the gain level of the camera C1 such as "Please raise and adjust." Or "Please adjust the brightness with IR-LED or lighting if necessary." It generates advice information that it is necessary to adjust the brightness of the imaging region imaged by the camera C1 with other lighting different from the lighting unit 14 (IR-LED) or the lighting unit 14 included in the camera C1.

On the other hand, when the terminal device P1 determines that the captured image is overexposed and determines that the captured time zone is daytime, "it is clear that the difference between the maximum brightness and the minimum brightness of the plate becomes large." Generate advice information to the effect that adjustment to raise the brightness correction of the camera C1 is necessary, such as "Please raise the correction." When the terminal device P1 determines that the captured image is overexposed and the captured time zone is nighttime, "the gain level is set so that the difference between the maximum brightness and the minimum brightness of the plate becomes large." Advice information that it is necessary to adjust the gain level by setting the camera C1 such as "Please lower and adjust." Or "Adjust the brightness with IR-LED or lighting if necessary." Generates advice information indicating that it is necessary to adjust the brightness of the imaging region imaged by the camera C1 with the illumination unit 14 (IR-LED) or other illumination different from the illumination unit 14 included in the camera C1. do.

It should be noted that the user may determine whether or not the captured image described above is underexposed or overexposed. Similarly, the user may determine whether the time zone in which the license plate NP is imaged is daytime or nighttime. In such a case, the terminal device P1 depends on the input operation by the user whether the captured image is blacked out or overexposed, and by the user whether the captured time zone is daytime or nighttime. The input operation is accepted via the input unit 23. The terminal device P1 generates advice information based on the user input. It should be noted that the determination of whether or not the captured image is blacked out or overexposed is not essential and may be omitted.

The terminal device P1 calculates (analyzes) the ratio of the measured brightness difference ΔL that satisfies the achievement condition among all the license plate NPs to which the same vehicle ID is given as the brightness difference appropriate rate for this vehicle ID. Further, when the terminal device P1 receives the analysis request of the brightness difference appropriateness rate of all the vehicle IDs recognized in all the captured images by the user operation, the achievement condition among the license plate NPs of all the vehicle IDs. The ratio at which the brightness difference ΔL satisfying the above conditions is measured is calculated (analyzed) as the brightness difference appropriate rate of all vehicle IDs. As a result, the terminal device P1 can more accurately acquire an image of the license plate NP having a sufficient brightness difference to perform recognition of each character information of the license plate NP based on the calculated brightness difference appropriate rate. It is possible to determine whether or not the camera C1 is set.

(Analysis processing of frame ratio in detection area)
Further, the terminal device P1 analyzes the frame ratio in the detection area based on the number of license plate NPs detected in the second detection zone among all the license plate NPs detected in the detection area of the camera C1. .. The terminal device P1 determines in which detection zone the license plate NP detected in each detection area of the camera C1 is detected. Specifically, the terminal device P1 determines in which detection zone of each detection area each of the two midpoints PS3 and PS4 of the license plate NP is detected. The terminal device P1 determines that the achievement condition is satisfied when both the two midpoints PS3 and PS4 are detected in the first detection zone. Further, the terminal device P1 determines that the achievement condition is not satisfied when any one of the two midpoints PS3 and PS4 is detected in the second detection zone.

The terminal device P1 is detected in the second detection zone of all the license plate NPs detected in each detection area of the camera C1 as a result of the determination processing of the detection zone in which each of all the license plate NPs is detected. The frame ratio in the detection area is calculated (analyzed) based on the number of license plate NPs, and it is determined whether or not the license plate NPs can be detected more appropriately in each detection area. When the terminal device P1 determines that the frame ratio in the detection area is equal to or higher than a predetermined value (for example, 90%, 95%, etc.) set by the user, the license plate NP is set in each currently set detection area. Judge that it can be detected appropriately. When the terminal device P1 determines that the detection area inner frame ratio is not equal to or higher than the predetermined value set by the user, the terminal device P1 "is a number recognition application so as to fit in the detection area inner frame (dotted line) so as not to be affected by the traveling route of the vehicle. Generate advice information that the license plate NP may not be detected more appropriately in the currently set detection area such as "Please adjust the detection area on the setting screen." As a result, the terminal device P1 recognizes each character information of the license plate NP based on the calculated detection area inner frame ratio, and the detection area set in the current camera C1 is within a more appropriate range. It can be determined whether or not it is set.

The terminal device P1 calculates (analyzes) the detection area frame ratio in the vehicle having this vehicle ID detected in the first detection zone AR11 among the license plate NPs of the vehicles to which the same vehicle ID is given. .. Further, when the terminal device P1 receives the analysis request of the detection area inner frame ratio in all the vehicle IDs by the user operation, the achievement condition (that is, the first one) among all the detected license plate NPs. The ratio that satisfies (detection) in the detection zone of is calculated (analyzed) as the frame ratio within the detection area of all vehicle IDs. Thereby, the terminal device P1 can determine whether or not an appropriate detection area is set by the detection of the license plate NP based on the calculated (analyzed) detection area inner frame ratio.

(Analysis processing of serial number match rate)
Further, the terminal device P1 has the highest serial number among all the serial numbers recognized in all the license plate NPs of the vehicles with the same vehicle ID detected in each detection area of the camera C1 (hereinafter,). , "Maximum sequence number") is determined, and the sequence number matching rate is calculated (analyzed) based on the number of the most sequence numbers among all the recognized sequence numbers. When the terminal device P1 determines that the calculated serial number matching rate is equal to or higher than a predetermined value (for example, 95%, 98%, etc.), it is determined that there is a low possibility that the recognized serial number is erroneously recognized. do. On the other hand, when the terminal device P1 determines that the calculated serial number matching rate is not equal to or higher than a predetermined value, it determines that there is a high possibility that the recognized serial number is erroneously recognized, and the analysis result of other analysis items. Advice information is generated based on the analysis items that do not meet the achievement conditions. For example, when the terminal device P1 determines that each of the serial number matching rate, the pixel number appropriate rate, and the plate inclination appropriate rate does not satisfy the achievement conditions, the pixel number appropriate rate or the plate inclination appropriate rate, respectively, is determined. When the advice information generated when the achievement condition is not satisfied is generated, or when it is determined that each of the serial number matching rate and the brightness difference appropriate rate does not meet the achievement condition, the achievement condition of the brightness difference appropriate rate is determined. Generates advice information that is generated when the above is not satisfied. As a result, the terminal device P1 can visualize the rate of erroneous recognition of the recognition result of the most serial numbers executed by the camera C1 based on the calculated (analyzed) serial number matching rate, and each of the other analysis items. Based on the achievement status of the achievement condition (that is, the determination result of whether or not the achievement condition is satisfied), advice information regarding the installation or setting of the camera C1 can be generated.

(Analysis processing of the number of recognition results)
Further, the terminal device P1 calculates the total number of license plate NPs for which recognition of each character information is executed among the license plate NPs of all vehicles imaged by the camera C1 (hereinafter referred to as "recognition result number") (hereinafter referred to as "recognition result number"). To analyze. The terminal device P1 determines whether or not the calculated (analyzed) number of recognition results is equal to or greater than a predetermined value (for example, 9 or more). When the terminal device P1 determines that the number of recognition results is equal to or greater than a predetermined value, it determines that the number of samples for generating the best shot image of each vehicle is sufficient. On the other hand, when the terminal device P1 determines that the calculated (analyzed) number of recognition results is not equal to or greater than a predetermined value, it determines that the number of samples for generating the best shot image of each vehicle is not sufficient, and determines that the number of samples is not sufficient. Please adjust the depression angle and swing angle of the camera so that the number of cameras is more than a certain number. ”, Etc. Generate advice information that the depression angle or mounting angle of the camera C1 needs to be adjusted. Thereby, the terminal device P1 can determine whether or not the depression angle or the mounting angle of the camera C1 is adjusted more appropriately based on the calculated (analyzed) number of recognition results.

As described above, the terminal device P1 generates the number recognition result screen SC0 and the analysis result display area DT17 included in the number recognition result screen SC0. Here, with reference to FIG. 6, the number recognition result screen SC0 generated by the process of step St8 and the analysis result display area DT17 generated by the process of step St9 will be described. FIG. 6 is a diagram showing an example of the number recognition result screen SC0.

The number recognition result screen SC0 shows each recognition result transmitted from the camera C1, display recognition result data DT0 including each of the generated plurality of plate images NP1 to NP4, analysis result for each set detection area, and analysis result. It is generated including each of the analysis result display tabs ARA and ARB for displaying the advice information, the setting screen button BT1, and the plate position confirmation button BT2 for displaying the plate position drawing image. The number recognition result screen SC0 shown in FIG. 6 shows an example in which two detection areas (“detection area 1” and “detection area 2”) are set, but the number of detection areas to be set is determined. Needless to say, it is not limited to this.

The display recognition result data DT0 is an area in which each of the generated plurality of plate images NP1 to NP4 and each recognition result based on the generated captured images of each of these plate images NP1 to NP4 are displayed. .. Although the number of display of the plate image and the recognition result included in the display recognition result data DT0 shown in FIG. 6 is four, it may be three or less, or five or more. Needless to say, it's good.

The license plate image field DT1 displays each of the generated plurality of plate images NP1 to NP4. In the license plate image column DT1, thumbnail images of each of the plurality of plate images NP1 to NP4 may be displayed. For example, in the example shown in FIG. 6, the license plate image column DT1 is the plate images NP1 and NP3 of the license plate of “Tama 〇〇〇sa △△ － ××” and “Setagaya △△△ a ×× －〇”. Each of the plate images NP2 and NP4 of the license plate of "○" is displayed.

The Land Transport Office column DT2 shows the recognition result of recognizing the Land Transport Office information among the character information of the license plates displayed in the captured images corresponding to the plurality of plate images NP1 to NP4, which are executed by the camera C1. For example, in the example shown in FIG. 6, in the land transportation branch office column DT2, the land transportation branch office information of the plate image NP1 is "Tama", the land transportation branch office information of the plate image NP2 is "Setagaya", and the land transportation branch office information of the plate image NP3 is "Tama". Plate image NP4 shows that the Land Transport Office information is "Setagaya".

The vehicle type column DT3 shows the recognition result of recognizing the vehicle type information of the vehicle among the character information of the license plates displayed in the captured images corresponding to the plurality of plate images NP1 to NP4, which are executed by the camera C1. For example, in the example shown in FIG. 6, in the vehicle type column DT3, the vehicle type information of the plate image NP1 is "○○○", the vehicle type information of the plate image NP2 is "△△△", and the vehicle type information of the plate image NP3 is "○○○". , Indicates that the vehicle type information of the plate image NP4 is "△△△".

The type column DT4 shows the recognition result of recognizing the vehicle type information among the character information of the license plates displayed in the captured images corresponding to the plurality of plate images NP1 to NP4, which are executed by the camera C1. For example, in the example shown in FIG. 6, in the type column DT4, the type information of the plate image NP1 is "sa", the type information of the plate image NP2 is "a", the type information of the plate image NP3 is "sa", and the plate image NP4. Indicates that the type information is "A".

The serial number column DT5 shows the recognition result of recognizing the serial number information among the character information of the license plates displayed in the captured images corresponding to the plurality of plate images NP1 to NP4, which are executed by the camera C1. For example, in the example shown in FIG. 6, in the serial number column DT5, the serial number information of the plate image NP1 is "△△ XX", the serial number information of the plate image NP2 is "XXX ○○", and the serial number of the plate image NP3. It indicates that the information is "△△ XX" and the serial number information of the plate image NP4 is "XX ○○".

The vehicle identification ID column DT6 is assigned for each vehicle and indicates a vehicle ID assigned to make each vehicle identifiable. The vehicle ID may be set by the user in advance, or may be assigned by the terminal device P1 based on each recognition result acquired by the camera C1. For example, in the example shown in FIG. 6, in the vehicle identification ID column DT6, the vehicle ID assigned to the vehicle corresponding to the plate image NP1 is "2A", and the vehicle ID assigned to the vehicle corresponding to the plate image NP2 is "38". , The vehicle ID assigned to the vehicle corresponding to the plate image NP3 is "2A", and the vehicle ID assigned to the vehicle corresponding to the plate image NP4 is "38".

The time column DT7 indicates the imaging time at which the captured images corresponding to the respective plate images NP1 to NP4 were captured. For example, in the example shown in FIG. 6, in the time column DT7, the imaging date and time information in which the captured image corresponding to the plate image NP1 was captured is "12: 11: 12.34", and the captured image corresponding to the plate image NP2 is captured. The imaging date and time information is "12: 11: 12.66", the imaging date and time information corresponding to the plate image NP3 is "12: 11: 12.34", and the captured image corresponding to the plate image NP4 is. It shows that the image capture date and time information captured is "12: 11: 12.66".

The area column DT8 indicates a detection area in which each of a plurality of plate images NP1 to NP4 is detected among one or more set detection areas. For example, in the example shown in FIG. 6, in the area column DT8, the detection area information in which the license plate corresponding to the plate image NP1 is detected is "1", and the detection area information in which the license plate corresponding to the plate image NP2 is detected is "1". 2 ”indicates that the detection area information in which the license plate corresponding to the plate image NP3 is detected is “1”, and the detection area information in which the license plate corresponding to the plate image NP4 is detected is “2”.

The width column DT9 indicates the plate width ΔX of each license plate detected in the captured images corresponding to each of the plurality of plate images NP1 to NP4. The unit of the plate width ΔX is “pixel (px)”. For example, in the example shown in FIG. 6, in the width column DT9, the plate width ΔX in the plate image NP1 is “160”, the plate width ΔX in the plate image NP2 is “130”, the plate width ΔX in the plate image NP3 is “160”, and the plate. It is shown that the plate width ΔX in the image NP4 is “130”.

The tilt column DT10 indicates the plate tilt θ of each license plate detected in the captured images corresponding to each of the plurality of plate images NP1 to NP4. The unit of the plate inclination θ is “degree (°)”. For example, in the example shown in FIG. 6, in the tilt column DT10, the plate tilt θ in the plate image NP1 is “5”, the plate tilt θ in the plate image NP2 is “18”, the plate tilt θ in the plate image NP3 is “5”, and the plate. It is shown that the plate inclination θ in the image NP4 is “18”.

The luminance difference column DT11 shows a luminance difference which is a difference value between the maximum luminance value and the minimum luminance value of each license plate detected in the captured images corresponding to each of the plurality of plate images NP1 to NP4. For example, in the example shown in FIG. 6, in the brightness difference column DT11, the brightness difference ΔL in the license plate displayed on the plate image NP1 is “80”, the brightness difference ΔL in the license plate displayed on the plate image NP2 is “30”, and the plate image NP3. It is shown that the luminance difference ΔL in the license plate reflected is “80” and the luminance difference ΔL in the license plate reflected in the plate image NP4 is “30”.

The in-area position column DT12 indicates in which detection zone in each detection area each license plate detected in the captured images corresponding to each of the plurality of plate images NP1 to NP4 is detected. Specifically, the terminal device P1 has a second detection zone when at least one of the two midpoints PS3 and PS4 of the detected license plate is detected in the second detection zone. (An example of "Zone B") If it is determined that each of the two midpoints PS3 and PS4 of the detected license plate is detected in the first detection zone, the first detection zone (1st detection zone) It is determined to be an example of "Zone A"). For example, in the example shown in FIG. 6, in the area position column DT12, the plate image NP1 is detected from the detection zone indicated by "Zone A", the plate image NP2 is detected from the detection zone indicated by "Zone B", and the plate is displayed. It shows that the image NP3 was detected from the detection zone indicated by "Zone A" and the plate image NP4 was detected from the detection zone indicated by "Zone B".

The left center coordinate column DT13 indicates the coordinates of the midpoint PS3 of each of the two midpoints PS3 and PS4 of each license plate detected in the captured images corresponding to the plurality of plate images NP1 to NP4. For example, in the example shown in FIG. 6, in the left center coordinate column DT13, the left center coordinate of the license plate displayed on the plate image NP1 is "1550,150", and the left center coordinate of the license plate displayed on the plate image NP2 is "1551,151". , The left center coordinate of the license plate displayed on the plate image NP3 is "1551,152", and the left center coordinate of the license plate displayed on the plate image NP4 is "1550,153".

The right center coordinate column DT14 indicates the coordinates of the midpoint PS4 of each of the two midpoints PS3 and PS4 of each license plate detected in the captured images corresponding to the plurality of plate images NP1 to NP4. For example, in the example shown in FIG. 6, in the right center coordinate column DT14, the right center coordinate of the license plate displayed on the plate image NP1 is "2150,550", and the right center coordinate of the license plate displayed on the plate image NP2 is "2150,550". , The right center coordinate of the license plate displayed on the plate image NP3 is "2150,550", and the right center coordinate of the license plate displayed on the plate image NP4 is "2150,550".

The low-luminance value column DT15 indicates the minimum luminance value of each license plate detected in the captured images corresponding to each of the plurality of plate images NP1 to NP4. For example, in the example shown in FIG. 6, in the low brightness value column DT15, the minimum brightness value of the plate image NP1 is "97", the minimum brightness value of the plate image NP2 is "70", and the minimum brightness value of the plate image NP3 is "97". , Indicates that the minimum luminance value of the plate image NP4 is "70".

The high-luminance value column DT16 indicates the maximum luminance value of each license plate detected in the captured images corresponding to each of the plurality of plate images NP1 to NP4. For example, in the example shown in FIG. 6, in the high brightness value column DT16, the maximum brightness value of the plate image NP1 is "177", the maximum brightness value of the plate image NP2 is "100", and the maximum brightness value of the plate image NP3 is "177". , Indicates that the maximum luminance value of the plate image NP4 is “100”.

Analysis result display tabs ARA and ARB are tabs for displaying analysis results and advice information corresponding to each detection area. When the analysis result display tab ARA is selected (pressed) by the user operation, the analysis result and advice information regarding the license plate of the vehicle detected in the detection area in which the name of the detection area is set as "detection area 1" are displayed. indicate. When the analysis result display tab ARB is selected (pressed) by the user operation, the analysis result and advice information regarding the license plate of the vehicle detected in the detection area in which the name of the detection area is set as "detection area 2" are displayed. indicate.

The analysis result display area DT17 shown in FIG. 6 displays the analysis result and advice information regarding the license plate of the vehicle when the analysis result display tab ARA is selected. When the vehicle list column LT1 is selected (pressed) by a user operation, the vehicle ID as a target for displaying the analysis result and the advice information among the vehicle IDs detected in the "detection area 1" is pulled down and displayed. For example, when the vehicle list column LT1 is selected (pressed) by a user operation, "all vehicle IDs", "2A", "38", etc. are pulled down and displayed. The terminal device P1 generates analysis results and advice information based on each recognition result of the vehicle ID selected by the user operation in the vehicle list column LT1 and displays them in the analysis result display area DT17.

The terminal device P1 generates an analysis result display area DT17 including analysis results of each analysis item and advice information based on the analysis results, and generates a number recognition result screen SC0 including the analysis result display area DT17 on the monitor 24. indicate.

For example, in the example shown in FIG. 6, in the analysis result display area DT17, as the analysis result and advice information of each analysis item, the analysis result "plate width appropriateness rate 95%" and the message "detection area / distance / "The depression angle and swing angle are appropriate", the analysis result about the plate tilt appropriate rate "Plate tilt appropriate rate 90%" and the advice information "Please adjust the depression angle and swing angle", the analysis result about the brightness difference appropriate rate "Brightness difference appropriate rate 60%" and advice information "Please adjust the brightness", analysis result "Detection area rate 95%" and message "Vehicle passing position is appropriate". Analysis result about the number of recognition results "Number of recognition results 5" and advice information "Please adjust if the vehicle speed is too fast", and analysis result about the recognition result match rate as an example of the serial number match rate "Recognition" Includes "Result match rate 90%" and advice information "Sequential numbers do not match partly. In the detection area ...". Note that the advice information regarding the recognition result matching rate shows an example in which only a part is shown, and the full text can be confirmed by a user operation (for example, a scroll operation or the like). Further, the message shown in FIG. 6 is notification information for notifying the user that the analysis result is appropriate.

When the setting screen button BT1 is selected (pressed) by a user operation, a setting screen (not shown) for setting various parameters of the camera C1 (for example, parameters such as gain level, bright part correction, dark part correction, etc.) is displayed. It is a button to display.

When the plate position confirmation button BT2 is selected (pressed) by a user operation, a plate position drawing image (for example, plate position drawing images CI1, CI2, CI3, CI4, CI5, CI6, CI7 shown in FIGS. 7 to 10) (For example, the plate position confirmation screens SC1, SC2, SC3, SC4, SC5, SC6, SC7 shown in FIGS. 7 to 10). When the plate position confirmation button BT2 is selected (pressed) by the user operation, the terminal device P1 generates a plate position drawing image, generates a plate position confirmation screen including the plate position drawing image, and displays it on the monitor 24. do.

Next, an example of the plate position confirmation screen will be described with reference to FIGS. 7 to 10. FIG. 7 is a diagram showing an example of plate position confirmation screens SC1 and SC2 before and after camera installation support. FIG. 8 is a diagram showing an example of plate position confirmation screens SC3 and SC4 before and after camera installation support. FIG. 9 is a diagram showing an example of plate position confirmation screens SC5 and SC6 before and after camera installation support. FIG. 10 is a diagram showing an example of the plate position confirmation screen SC7 when each of the plurality of detection areas AR6 and AR7 is set.

In each of the plate position confirmation screens SC1 to SC7, the two points and straight lines indicating the plate positions of the plurality of number plates detected in each detection area are one of the plate position drawing images CI1 shown in FIG. A code is assigned only to the portion, and the addition of the code is omitted in each of the other plate position drawing images CI2 to CI7.

First, each of the plate position confirmation screens SC1 to SC7 will be described. Each of the plate position confirmation screens SC1 to SC7 has a message MS saying "If checked, the condition unachieved data is displayed with a red dotted line." And all indexes (plate width ΔX, plate inclination θ, brightness difference ΔL, And the index list LT2 that can select one or more indexes that the user wants to judge whether or not the achievement condition is satisfied from the detection zone in the detection area), and the plate position when selected (pressed) by the user operation. It is generated including a save button BT3 for saving the plate position drawing image displayed on the confirmation screen, a vehicle list LT3 for confirming the plate position in each detection area, and a plate position drawing image.

Next, each of the plate position drawing images CI1 to CI7 will be described. Each of the plate position drawing images CI1 to CI7 has two midpoint PS3s indicating the respective positions of the plurality of number plate NPs detected from each captured image on the captured image with the detection area generated by the terminal device P1. A straight line connecting each of PS4 (for example, each of the points PP1 and PP2 shown in FIG. 7) and each of these two midpoints PS3 and PS4 (for example, a straight line SL1 connecting the points PP1 and PP2 shown in FIG. 7). ) Is superimposed and displayed. Here, the terminal device P1 is a color and a straight line of points to be superimposed based on a determination result of whether or not each achievement condition of one or more indexes specified (selected) by the user in the index list LT2 is satisfied. By changing the line type of, it is visualized whether or not each of the plurality of license plate NPs indicated by the two points and the straight line satisfies the achievement conditions of the index specified (selected) by the user. ..

Here, the drawing process of the plate position (that is, the position of the license plate NP) executed by the terminal device P1 will be described.

In generating the plate position drawing image, the terminal device P1 has each index specified in the index list LT2 (for example, in the example of the plate position confirmation screen SC1 shown in FIG. 7, the plate width ΔX of the license plate NP, the plate inclination θ, And each of the brightness difference ΔL), it is determined whether or not each of the detected plurality of license plate NPs satisfies the achievement condition. Further, the terminal device P1 determines whether or not the positions of the two points indicating the positions of the license plate NPs are located in the first detection zone based on the determination result. As a result of these determinations, the terminal device P1 superimposes two points indicating the positions of the license plate NPs that do not satisfy the achievement conditions on the captured image with the detection area in red. Further, when at least one of the two points is superimposed in red, the terminal device P1 superimposes the straight line connecting these two points in red and in a broken line.

Hereinafter, a specific drawing example of the plate position (that is, the position of the license plate NP) will be described with reference to the plate position drawing image CI1 shown in FIG.

For example, in generating the plate position drawing image CI1 shown in FIG. 7, the terminal device P1 is based on the respective indexes of the plate width ΔX, the plate inclination θ, and the brightness difference ΔL of the license plate NP specified in the index list LT2. It is determined whether or not each of the detected plurality of license plate NPs satisfies the achievement condition. Further, the terminal device P1 determines whether or not the positions of the two points indicating the positions of the license plate NPs are located in the first detection zone AR21 based on the determination result. As a result of these determinations, the terminal device P1 has two points indicating the positions of the license plate NPs that do not satisfy the achievement conditions and the positions of the two points indicating the positions of the license plate NPs in the first detection zone AR21. The points determined not to be located at are superimposed in red on the captured image with the detection area. Further, when at least one of the two points is superimposed in red, the terminal device P1 superimposes the straight line connecting these two points in red and in a broken line.

For example, each of the two points PP1 and PP2 is a point determined not to satisfy any of the achievement conditions of each index, and is superimposed in red on the captured image with the detection area. The straight line SL1 connecting the point PP1 and the point PP2 is a point where it is determined that neither of the two points PP1 and PP2 satisfies any of the achievement conditions of each index, so that the detection area It is superimposed on the captured image with a red dashed line.

Further, for example, each of the two points PP3 and PP4 is a point determined to satisfy the achievement conditions of all the indexes, and is superimposed in blue on the captured image with the detection area. Since the straight line SL2 connecting the point PP3 and the point PP4 is a point where it is determined that both the two points PP3 and PP4 satisfy the achievement conditions of all the indexes, the captured image with the detection area is blue. Overlaid with solid lines.

Further, for example, the point PP5 indicating the midpoint of the left short side of the license plate NP (that is, the left center coordinate) is determined not to satisfy any of the achievement conditions of each index. Yes, it is superimposed in red on the captured image with the detection area. The midpoint of the right short side of the license plate NP (that is, the right center coordinate) is a point determined to satisfy the achievement conditions of all the indexes, and is superimposed in blue on the captured image with the detection area. Since the straight line SL3 connecting the point PP5 and the point PP6 is a point where it is determined that one of the points PP5 does not satisfy any of the achievement conditions of each index, imaging with a detection area is provided. It is superimposed on the image with a red dashed line.

As described above, the user can use the positions of both ends of each license plate NP (specifically, each middle point in the short side direction of the license plate NP) based on the positions of the two points and the slope of the straight line. The plate inclination of each license plate NP can be confirmed at a glance, and it can be confirmed whether or not the camera C1 is installed and set more suitable for the recognition of the license plate NP by the camera C1. In addition, when the user actually operates the currently installed camera C1 based on the plate position drawing images CI1 to CI7, the license plate NP of the vehicle is at what position and at what angle on the captured image. It becomes easier to imagine whether it will be reflected.
Therefore, the camera installation support system 100 can support the installation and setting of the camera C1 desired by the user.

The plate position confirmation screen SC1 shown in FIG. 7 is displayed including the plate position drawing image CI1. The plate position drawing image CI1 is a detection area in which a frame line indicating the detection area AR2 and a broken line for indicating each of the first detection zone AR21 and the two second detection zones AR22 of the detection area AR2 are superimposed. The captured image with is shown the plate position of each of the 13 license plate NPs.

As a result, the user can use each of the plurality of indexes specified in the index list LT2 (that is, based on the color of the point indicating each plate position drawn (superimposed) on the plate position drawing image CI1 and the color of the straight line and the line type. , Plate width ΔX, plate inclination θ, or brightness difference ΔL), it is possible to intuitively confirm at a glance that the achievement condition is not satisfied. That is, the camera installation support system 100 can efficiently support the installation and setting of the camera C1 desired by the user by the plate position drawing image CI1.

Further, on the plate position confirmation screen SC2 shown in FIG. 7, the user sets the mounting position, mounting angle, depression angle or swing angle of the camera C1, the lighting unit 14 of the camera C1 or various parameters (for example, adjustment of gain level, dark area). This is a screen generated by the terminal device P1 based on the captured image captured by the camera C1 again after the correction adjustment, the bright portion correction adjustment, etc. are executed, and the recognition result based on the captured image. The plate position confirmation screen SC2 is displayed including the plate position drawing image CI2. The plate position drawing image CI2 is a detection area in which a frame line indicating the detection area AR3 and a broken line for indicating each of the first detection zone AR21 and the two second detection zones AR22 of the detection area AR2 are superimposed. The captured image with is shown the plate position of each of the eight license plate NPs.

As a result, the user can increase the number plate NP in the set detection area AR2 based on the color of the point indicating each plate position drawn (superimposed) on the plate position drawing image CI2, the color of the straight line, and the line type. It is possible to intuitively confirm at a glance that the detection area has been set so that it can be detected accurately. That is, the camera installation support system 100 generates a plate position drawing image CI1 that visualizes the determination result of whether or not the achievement condition of the index specified by the user is satisfied for each of the detected plurality of license plate NPs. This makes it possible to efficiently support the installation and setting of the camera C1 desired by the user.

The plate position confirmation screen SC3 shown in FIG. 8 is displayed including the plate position drawing image CI3. Further, in the generation of the plate position drawing image CI3 shown in FIG. 8, for example, the terminal device P1 of a plurality of license plate NPs detected based on a detection area which is one index designated by the user in the index list LT2. Determine if each meets the achievement conditions. The plate position drawing image CI3 is a detection area in which a frame line indicating the detection area AR3 and a broken line for indicating each of the first detection zone AR31 and the two second detection zones AR32 of the detection area AR3 are superimposed. The captured image with is shown the plate position of each of the 12 license plate NPs.

As a result, the user can set the range of the detection area AR3 based on the color of the point indicating each plate position drawn (superimposed) on the plate position drawing image CI3, the color of the straight line, and the line type of the vehicle license plate. It can be efficiently confirmed at a glance that it is not suitable for NP detection.

Further, the plate position confirmation screen SC4 shown in FIG. 8 is a terminal based on the captured image captured by the camera C1 again after being changed from the detection area AR3 to the detection area AR4 by the user and each recognition result based on the captured image. This is a screen generated by the device P1. The plate position drawing image CI4 is a detection area in which a frame line indicating the detection area AR4 and a broken line for indicating each of the first detection zone AR41 and the two second detection zones AR42 of the detection area AR4 are superimposed. The captured image with is shown the plate position of each of the 12 license plate NPs.

As a result, the user can increase the number plate NP in the set detection area AR4 based on the color of the point indicating each plate position drawn (superimposed) on the plate position drawing image CI4, the color of the straight line, and the line type. It is possible to intuitively confirm at a glance that the detection area has been set so that it can be detected accurately. That is, the camera installation support system 100 generates a plate position drawing image CI3 that visualizes the determination result of whether or not the achievement condition of the index specified by the user is satisfied for each of the detected plurality of license plate NPs. This makes it possible to efficiently support the installation and setting of the camera C1 desired by the user.

The plate position confirmation screen SC5 shown in FIG. 9 is displayed including the plate position drawing image CI5. Further, the terminal device P1 is, for example, in generating the plate position drawing image CI5 shown in FIG. 9, of a plurality of license plate NPs detected based on the luminance difference which is one index specified by the user in the index list LT2. Determine if each meets the achievement conditions. In the example shown in FIG. 9, the region HL in the detection area AR5 indicates a range that is brightened by being exposed to strong light by the illumination unit 14 or other illumination. The plate position drawing image CI5 is a detection area in which a frame line indicating the detection area AR5 and a broken line for indicating each of the first detection zone AR51 and the two second detection zones AR52 of the detection area AR5 are superimposed. The captured image with is shown the plate position of each of the 12 license plate NPs.

As a result, the user can use the brightness of each of the number plate NPs detected in the region HL based on the color of the point indicating each plate position drawn (superimposed) on the plate position drawing image CI5, the color of the straight line, and the line type. It can be efficiently confirmed at a glance that the difference does not satisfy the achievement condition and the brightness is not more suitable for the camera C1 to perform the detection of the number plate NP and the recognition process of each character information.

Further, on the plate position confirmation screen SC6 shown in FIG. 9, the user sets the illumination unit 14 of the camera C1 or sets various parameters of the camera C1 (for example, gain level adjustment, dark area correction adjustment, bright area correction adjustment). Etc.), etc. are adjusted, and then the captured image captured by the camera C1 again, and the screen generated by the terminal device P1 based on each recognition result based on the captured image. The plate position confirmation screen SC6 is displayed including the plate position drawing image CI6. The plate position drawing image CI6 is a detection area in which a frame line indicating the detection area AR5 and a broken line for indicating each of the first detection zone AR51 and the two second detection zones AR52 of the detection area AR5 are superimposed. The captured image with is shown the plate position of each of the 12 license plate NPs.

As a result, the user can increase the number plate NP in the set detection area AR5 based on the color of the point indicating each plate position drawn (superimposed) on the plate position drawing image CI4, the color of the straight line, and the line type. It is possible to intuitively confirm at a glance that the lighting unit 14 of the camera C1 or the various parameters of the camera C1 have been set so that the detection can be performed accurately. That is, the camera installation support system 100 generates a plate position drawing image CI5 that visualizes the determination result of whether or not the achievement condition of the index specified by the user is satisfied for each of the detected plurality of license plate NPs. This makes it possible to efficiently support the installation and setting of the camera C1 desired by the user.

The plate position confirmation screen SC7 shown in FIG. 10 is an example of a plate position confirmation screen generated when each of the two detection areas AR6 and AR7 is set. The plate position confirmation screen SC7 is displayed including the plate position drawing image CI7. Further, the terminal device P1 detects all the indexes (that is, plate width ΔX, plate inclination θ, brightness difference ΔL, and detection) specified by the user in the index list LT2 when generating the plate position drawing image CI7 shown in FIG. Area), it is determined whether or not each of the plurality of license plate NPs detected in each of the two detection areas AR6 and AR7 satisfies the achievement condition. The plate position drawing image CI7 has a border indicating each of the two detection areas AR6 and AR7, and a broken line for indicating each of the first detection zone AR61 and the two second detection zones AR62 of the detection areas AR6. , A broken line for indicating each of the first detection zone AR71 and the two second detection zones AR72 of the detection area AR7, and each plate of the plurality of license plates NP on the captured image with the detection area superimposed. The position is shown.

As a result, the user can install the current camera C1 and install the current camera C1 based on the color of the point indicating the plate position, the color of the straight line, and the line type in each of the detection areas AR6 and AR7 drawn (superimposed) on the plate position drawing image CI7. It is possible to intuitively confirm at a glance whether or not the setting is more suitable for the detection process and the recognition process of the vehicle number plate in each of the detection areas AR6 and AR7 executed by the camera C1. That is, the camera installation support system 100 determines whether or not each of the plurality of license plate NPs detected in each of the two detection areas AR6 and AR7 satisfies the achievement condition of the index specified by the user. By generating the visualized plate position drawing image CI7, it is possible to efficiently support the installation and setting of the camera C1 desired by the user.

As described above, the camera installation support system 100 according to the first embodiment includes a terminal device P1 which is a computer communicably connected to the camera C1 for photographing the vehicle, and a plurality of images captured by the camera C1. From each of the images, the number plate NP of the vehicle reflected in one or more detection areas AR1 preset for the angle of view of the camera C1 is detected, and the detection result satisfies a plurality of imaging conditions (that is,). It is determined whether or not the achievement condition is satisfied), and advice information regarding the installation or parameter setting of the camera C1 is generated and output based on the determination result of whether or not each of the plurality of imaging conditions is satisfied.

As a result, in the camera installation support system 100 according to the first embodiment, each of the license plate NPs of the vehicle detected in the detection area AR1 set by the user recognizes each character information of the license plate NP. Based on the determination result of whether or not each imaging condition (each achievement condition) is satisfied, advice information regarding the installation or parameter setting of the camera C1 can be generated to support the installation or setting of the camera C1. The user can also adjust the current camera C1 installation or settings based on the generated advice information.

Further, as described above, the camera installation support system 100 according to the first embodiment has a pair of two midpoints in the lateral direction (for example, two midpoints shown in FIG. 3) in each of the detected plurality of license plate NPs. The coordinates of each of PS3 and PS4) are calculated, and the two midpoints for each license plate are plotted on the background image of the imaging region imaged by the camera C1. Plate position drawing images (for example, FIGS. 7 to 10) are shown. Plate position drawing images CI1 to CI7, etc.) are generated and output. The background image referred to here may be a captured image with a detection area. As a result, the camera installation support system 100 according to the first embodiment can visualize to the user an image of the plate width and plate inclination of the license plate NP imaged by the camera C1 during actual operation.

Further, as described above, the camera installation support system 100 according to the first embodiment has a plurality of license plate NPs based on the coordinates of the two midpoints (for example, the two midpoints PS3 and PS4 shown in FIG. 3). When it is determined that the width (plate width ΔX) is equal to or less than a predetermined value (for example, the achievement condition regarding the plate width ΔX shown in FIG. 4 is not satisfied), the advice information is provided. Output. As a result, the camera installation support system 100 according to the first embodiment determines whether or not the license plate NP displayed in the captured image has a size more suitable for the recognition process of each character information, and the camera based on the determination result. It is possible to output advice information regarding the installation or setting of C1. Therefore, the user confirms whether the current camera C1 installation or setting is more suitable for the recognition process of each character information of the license plate NP, and sets the current camera C1 installation or setting based on the advice information. Can be adjusted.

Further, as described above, the camera installation support system 100 according to the first embodiment has a plurality of license plate NPs based on the coordinates of the two midpoints (for example, each of the two midpoints PS3 and PS4 shown in FIG. 3). The detection ratio of the license plate NP in which a part of the license plate width (plate width ΔX) is detected outside the detection area among all the detected license plate NPs is calculated by calculating each width (plate width ΔX). If it is determined that the ratio is equal to or higher than the predetermined ratio, advice information is output. As a result, the camera installation support system 100 according to the first embodiment can output advice information regarding the current detection area setting, the installation of the camera C1, or the setting. Therefore, the user confirms whether the current detection area setting, the installation or setting of the camera C1 is more suitable for the recognition process of each character information of the license plate NP, and the current detection area based on the advice information. Settings, camera C1 installation or settings can be adjusted.

Further, as described above, the camera installation support system 100 according to the first embodiment has a plurality of license plate NPs based on the coordinates of the two midpoints (for example, each of the two midpoints PS3 and PS4 shown in FIG. 3). Each width (plate width ΔX) is calculated, and a plurality of second detection zones smaller than the detection area (for example, the second detection zone AR12 shown in FIG. 3) are set in the detection area, and the detection is performed. When it is determined that a part of the license plate width (plate width ΔX) of each of the plurality of license plate NPs is detected in the plurality of second detection zones, advice information is output. Thereby, the camera installation support system 100 according to the first embodiment can determine whether or not each of the detected plurality of license plate NPs is located in the central portion of the detection area. Therefore, the user can adjust the current detection area setting, the installation or setting of the camera C1 based on the advice information.

Further, as described above, in the camera installation support system 100 according to the first embodiment, a part of the width (plate width ΔX) of the license plate NPs among all the detected license plate NPs is in a plurality of second detection zones. When it is determined that the detection ratio of the license plate NP detected in is equal to or higher than a predetermined ratio, advice information is output. As a result, the camera installation support system 100 according to the first embodiment can output advice information based on the ratio of each of the detected plurality of license plate NPs located in the central portion of the detection area. Therefore, the user can adjust the current detection area setting, the installation or setting of the camera C1 based on the advice information.

Further, as described above, the camera installation support system 100 according to the first embodiment calculates the inclination (plate inclination θ) in the longitudinal direction of each of the detected plurality of number plate NPs, and the calculated inclination (plate inclination θ) is calculated. ) Is determined to be equal to or greater than the set predetermined angle, and the advice information is output. As a result, the camera installation support system 100 according to the first embodiment determines whether or not the number plate NP displayed in the captured image is imaged at an angle more suitable for the recognition process of each character information, and also determines whether or not the number plate NP is imaged. It is possible to output advice information regarding the installation or setting of the camera C1 based on the determination result. Therefore, the user confirms whether the current camera C1 installation or setting is more suitable for the recognition process of each character information of the license plate NP, and sets the current camera C1 installation or setting based on the advice information. Can be adjusted.

Further, as described above, the camera installation support system 100 according to the first embodiment calculates the maximum luminance value and the minimum luminance value of the pixels in each region of the detected license plate NP, and the maximum luminance value and the minimum luminance value. When it is determined that the brightness difference ΔL with and is less than a predetermined value, advice information is generated. As a result, the camera installation support system 100 according to the first embodiment determines whether or not the number plate NP displayed in the captured image is imaged with a brightness more suitable for the recognition process of each character information. , It is possible to output advice information regarding the installation or setting of the camera C1 based on the determination result. Therefore, the user confirms whether the current installation or setting of the camera C1 is more suitable for the recognition processing of each character information of the license plate NP, and based on the advice information, the user installs or sets the current camera C1. Alternatively, the arrangement, brightness, and the like of the lighting installed around the camera C1 can be adjusted.

Further, as described above, when the camera installation support system 100 according to the first embodiment determines that the brightness difference ΔL is less than a predetermined value, the camera installation support system 100 determines the advice information based on the imaging time of the captured image. As a result, in the camera installation support system 100 according to the first embodiment, the license plate NPs reflected in the captured image are each based on the surrounding environment in which the camera C1 is installed (that is, whether it is daytime or nighttime). It is possible to output advice information for imaging the license plate NP with a brightness more suitable for the character information recognition process. Therefore, the user confirms whether the current installation or setting of the camera C1 is more suitable for the recognition processing of each character information of the license plate NP, and based on the advice information, the user installs or sets the current camera C1. Alternatively, the arrangement, brightness, and the like of the lighting installed around the camera C1 can be adjusted.

Further, as described above, the camera installation support system 100 according to the first embodiment recognizes the vehicle number of the vehicle (that is, the vehicle serial number, the serial designation number, etc.) based on each of the detected license plates. The matching ratio of all the recognized vehicle numbers is calculated, and when it is determined that the ratio is equal to or less than a predetermined value, advice information is generated. Thereby, the camera installation support system 100 according to the first embodiment can determine the ratio of erroneously recognizing the serial number of the recognized vehicle.

Further, as described above, the camera installation support system 100 according to the first embodiment has a predetermined number or less of the number of recognized serial numbers (vehicle number, serial designation number, etc.) among all the detected license plate NPs. If it is determined that, advice information is generated. Thereby, the camera installation support system 100 according to the first embodiment can determine whether or not it is possible to generate the best shot image of the vehicle generated by the camera C1 during actual operation.

Further, as described above, the plate position drawing image generated by the camera installation support system 100 according to the first embodiment satisfies a plurality of imaging conditions (that is, the achievement conditions are satisfied) based on the determination result. ) The plate position and the plate position that does not satisfy the plurality of imaging conditions (that is, the achievement conditions are not satisfied) are drawn in different colors. As a result, the camera installation support system 100 according to the first embodiment can generate a plate position drawing image that visualizes whether or not the achievement condition is satisfied. Therefore, the user can efficiently confirm at a glance whether or not the achievement condition is satisfied.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications, modifications, substitutions, additions, deletions, and equality within the scope of the claims. It is understood that it naturally belongs to the technical scope of the present disclosure. Further, each component in the various embodiments described above may be arbitrarily combined as long as the gist of the invention is not deviated.

The present disclosure is useful as a camera installation support program, a camera installation support method, and a camera installation support system that support camera installation and improve the recognition accuracy of recognition processing using captured images.

10, 20 Communication unit 11,21 Processor 12, 22 Memory 13 Imaging unit 14 Lighting unit 23 Input unit 24 Monitor 25 HDD
AR1, AR2, AR3, AR4, AR5, AR6, AR7 Detection area AR11, AR21, AR31, AR41, AR51, AR61, AR71 First detection zone AR12, AR22, AR32, AR42, AR52, AR62, AR72 Second detection Zone C1 Camera CI1, CI2, CI3, CI4, CI5, CI6, CI7 Plate position drawing image P1 Terminal device SC1, SC2, SC3, SC4, SC5, SC6, SC7 Plate position confirmation screen NW network ΔX Plate width θ Plate tilt

Claims (13)

To a terminal device, which is a computer that is communicably connected to a camera that captures at least one vehicle.
A step of detecting the license plate of the vehicle reflected in the preset detection area from each of the plurality of captured images captured by the camera, and
A step to determine whether the detection result satisfies the achievement condition of at least one specified index, and
In the background image of the imaging region imaged by the camera, two points indicating the positions of the license plates detected respectively and the determination result of whether or not the achievement conditions are satisfied at those positions can be clarified. In order to realize the step of generating and outputting the plate position drawing image plotted for each license plate .
Camera installation support program. Further, in order to further realize the step of generating and outputting the advice information of the camera installation or parameter setting based on the determination result of whether or not the achievement condition is satisfied.
The camera installation support program according to claim 1. A step of calculating the width of each of the plurality of license plates based on the coordinates of a pair of midpoints in the lateral direction in each of the plurality of detected license plates, and a step of calculating the width of each of the plurality of license plates.
When it is determined that the calculated width is equal to or less than a predetermined value, the step of generating and outputting the advice information is further realized.
The camera installation support program according to claim 2. A step of calculating the width of each of the plurality of license plates based on the coordinates of a pair of midpoints in the lateral direction in each of the plurality of detected license plates, and a step of calculating the width of each of the plurality of license plates.
When it is determined that a part of the width of the license plate is detected outside the detection area and the detection ratio of the license plate is equal to or more than a predetermined ratio among all the detected license plates, the advice information is generated. To further realize the output step,
The camera installation support program according to claim 2. A step of calculating the width of each of the plurality of license plates based on the coordinates of a pair of midpoints in the lateral direction in each of the plurality of detected license plates, and a step of calculating the width of each of the plurality of license plates.
It is said that a plurality of detection zones smaller than the detection area are set in the detection area, and a part of the width of the license plate among the detected license plates is detected in the plurality of detection zones. If it is determined, the step of generating and outputting the advice information is further realized.
The camera installation support program according to claim 2. When it is determined that a part of the width of the license plate is detected in the plurality of detection zones and the detection ratio of the license plate is equal to or more than a predetermined ratio among all the detected license plates, the advice information is generated. To further realize the step of outputting
The camera installation support program according to claim 5. A step of calculating the inclination of each of the detected plurality of license plates in the longitudinal direction, and
When it is determined that the calculated inclination is equal to or greater than the set predetermined angle, the step of generating and outputting the advice information is further realized.
The camera installation support program according to claim 2. A step of calculating the maximum luminance value and the minimum luminance value of the detected pixels in each region of the license plate, and
When it is determined that the brightness difference between the maximum brightness value and the minimum brightness value is less than a predetermined value, the step of generating and outputting the advice information is further realized.
The camera installation support program according to claim 2. In the plate position drawing image, based on the determination result, the position of the license plate that satisfies the achievement condition is drawn in blue, and the position of the license plate that does not satisfy the achievement condition is drawn in red.
The camera installation support program according to claim 1. In the plate position drawing image, based on the determination result, the position of the license plate satisfying the achievement condition is drawn with a solid line, and the position of the license plate not satisfying the achievement condition is drawn with a broken line.
The camera installation support program according to claim 1. Each of the plurality of captured images is a captured image for a predetermined period captured by the camera.
The camera installation support program according to claim 1. This is a camera installation support method for a camera installation support system in which a camera and a terminal device are connected so that they can communicate with each other.
From each of the plurality of captured images captured by the camera, the license plate of at least one vehicle reflected in the preset detection area is detected.
It is determined whether or not the detection result satisfies the achievement condition of at least one specified index.
In the background image of the imaging region imaged by the camera, two points indicating the positions of the license plates detected respectively and the determination result of whether or not the achievement conditions are satisfied at those positions can be clarified. Generates and outputs a plate position drawing image plotted for each license plate .
Camera installation support method. With the camera
A camera installation support system including a terminal device communicatively connected to the camera.
The camera
Each of the plurality of captured images captured is transmitted to the terminal device, and the image is transmitted to the terminal device.
The terminal device is
The license plates of at least one vehicle are detected from the preset detection areas of the plurality of captured images, respectively.
It is determined whether or not the detection result satisfies the achievement condition of at least one specified index.
In the background image of the imaging region imaged by the camera, two points indicating the positions of the license plates detected respectively and the determination result of whether or not the achievement conditions are satisfied at those positions can be clarified. Generates and outputs a plate position drawing image plotted for each license plate .
Camera installation support system.

Images