Search system and search method

Abstract

To provide a search system capable of improving continuity of a search service, and reducing a network load.SOLUTION: A search system comprises: a detailed information database that collects detailed information containing images obtained by photographing number plates from a plurality of number plate reading devices that read the number plates of vehicles and processing result information containing number plate information read from the images; a simple information database that stores simple information of which information amount is smaller than that of the detailed information; and a terminal device that acquires the simple information and the detailed information that match designated search conditions from the simple information database and the detailed information database.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a search system and a search method.

Background Art

[0002] In recent years, number plate reading devices that acquire number plate information from images of vehicle number plates have been installed at various locations such as toll roads, general roads, and parking lots. The images captured by the number plate reading devices and the read number plate information are aggregated, for example, in a single central device (database) and used for vehicle monitoring and tracking. For example, Patent Document 1 describes a vehicle tracking system that searches for images and information of vehicles that match the number plate information of a target vehicle from a large number of vehicle data stored in a central device and displays them on a user's terminal device (the in-vehicle device of the tracking vehicle).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In some cases, the license plate information of the tracked vehicle may be unknown. In this case, the central unit needs to accept the specification of search conditions, such as a specific location or date and time, and search for multiple images that match the search conditions from the stored images and send them to the terminal device. In such vehicle tracking systems, the central unit stores high-resolution (large data size) images that can be used to identify the tracked vehicle. As a result, the image search processing at the central unit takes time, and the network load when transmitting images from the central unit to the terminal device becomes high. Furthermore, if the search conditions are incorrect or ambiguous and the search range is wide, it may be necessary to change the search conditions and run the search process multiple times, or there may be many candidate images that match the search conditions. This would further increase the processing load on the central unit and the network load. Also, if the central unit needs to perform other priority processing at this time, it may be necessary to temporarily suspend the search process (stop the search service).

[0005] The purpose of this disclosure is to provide a search system and search method that can improve the continuity of search services and reduce network load. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, the search system comprises: a detailed information database that collects detailed information from a plurality of license plate readers that read the license plates of vehicles, including images of the license plates and processing result information including license plate information read from the images; a simplified information database that stores simplified information which is generated from the same images as the images included in the detailed information and has a smaller amount of information than the detailed information; and a terminal device that obtains the simplified information and detailed information that match specified search conditions from the simplified information database and the detailed information database, wherein the terminal device includes a simplified information acquisition unit that obtains the simplified information that matches the search conditions from the simplified information database, and a detailed information acquisition unit that selects at least one of the acquired simplified information and obtains detailed information corresponding to the selected simplified information from the detailed information database.

[0007] According to one aspect of the present disclosure, the search method is a search method using a search system comprising: a detailed information database that collects detailed information from a plurality of license plate readers that read the license plates of vehicles, including an image of the license plate and processing result information including license plate information read from the image; a simplified information database that stores simplified information which is generated from the same image as the image included in the detailed information and has a smaller amount of information than the detailed information; and a terminal device that obtains the simplified information and detailed information that match specified search conditions from the simplified information database and the detailed information database, the method comprising: the step of the terminal device obtaining simplified information that matches the search conditions from the simplified information database; and the step of the terminal device selecting at least one of the obtained simplified information and obtaining detailed information corresponding to the selected simplified information from the detailed information database. [Effects of the Invention]

[0008] According to the above embodiment, the search process can be sped up and the network load can be reduced. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows the overall configuration of a search system according to one embodiment. [Figure 2] This figure shows the functional configuration of a terminal device according to one embodiment. [Figure 3] This sequence diagram shows an example of the recording process for detailed and simplified information according to one embodiment. [Figure 4] This figure shows an example of detailed information and simplified information according to one embodiment. [Figure 5] This is a sequence diagram showing an example of a search process according to one embodiment. [Modes for carrying out the invention]

[0010] (Overall structure of the search system) Figure 1 shows the overall configuration of a search system according to one embodiment. The search system 1 according to this embodiment is a system for searching for vehicle information acquired by roadside devices 5 installed at toll booths on toll roads. Users of the search system 1 include, for example, operators of toll roads and enforcement agencies (such as the police) that track down violating vehicles.

[0011] The roadside device 5 includes a license plate reader 51 and a sensor 52.

[0012] The license plate reader 51 reads license plate information (such as place name, classification number, symbol, and serial number) from images taken of vehicles traveling at a specific location on the road (toll booth lane).

[0013] If a toll booth has multiple lanes, one license plate reader 51 is installed for each lane. Each license plate reader 51 photographs a vehicle traveling at a specific location in the lane where it is installed and reads the license plate information.

[0014] In other embodiments, one license plate reader 51 may be installed for a plurality of lanes. In this case, the license plate reader 51 captures a vehicle traveling at a specific position in each lane and reads license plate information.

[0015] The sensor 52 is a device for acquiring information about a vehicle (sensor information) other than license plate information.

[0016] The sensor 52 is, for example, a vehicle detector that detects a vehicle traveling at a specific position on a road. The license plate reader 51 can capture an image in which the license plate is clearly shown by taking a picture at the timing when the vehicle detector detects a vehicle, so that the reading accuracy of the license plate can be improved.

[0017] Also, the sensor 52 may be a distance meter such as LiDAR (Light Detection and Ranging). For example, when one license plate reader 51 is installed for a plurality of lanes, the LiDAR acquires sensor information (such as the distance from the installation position of the sensor 52 to the detection position of the vehicle) that can identify which lane the vehicle is traveling in. Note that the LiDAR may acquire sensor information (such as vehicle length, vehicle width, vehicle height, etc.) that can identify the vehicle type.

[0018] Note that the sensor 52 may be a sensor such as a treadle or axle scale installed at a tollgate. Also, the sensor 52 may be a group of devices combining the above-described plurality of sensors.

[0019] Also, as shown in FIG. 1, the search system 1 includes a detailed information database (DB) 2, a simple information database (DB) 3, and a terminal device 4. <00​​The detailed information DB2 is a database that collects and stores the detailed information D1 acquired by each roadside device 5. For example, the detailed information D1 includes an image (high-quality image) captured by the license plate reader 51, and processing result information (license plate information, sensor information, etc.) of the license plate reader 51 and the sensor 52.

[0021] The simple information DB3 is a database that stores simple information D2 generated from the same image as the image included in the detailed information D1 and having a smaller amount of information (smaller data size) than the detailed information D1. The simple information D2 is information generated corresponding to the detailed information D1. The simple information D2 is, for example, at least one of meta information D2a obtained by extracting a part of the detailed information D1 and thumbnail information D2b including a thumbnail (low-quality image) obtained by reducing the image captured by the license plate reader 51. In the present embodiment, the simple information DB3 includes a meta information DB31 that stores the meta information D2a and a thumbnail DB32 that stores the thumbnail information D2b.

[0022] The terminal device 4 is communicably connected to the detailed information DB2 and the simple information DB3 via a network N such as the Internet. The terminal device 4 acquires the simple information D2 and the detailed information D1 that match the search conditions specified by the user from the simple information DB3 and the detailed information DB2.

[0023] In the present embodiment, the terminal device 4 performs two-stage data acquisition processing of first acquiring the simple information D2 that matches the search conditions from the simple information DB3, and then acquiring the detailed information D1 corresponding to the acquired simple information D2 from the detailed information DB2. In this way, by narrowing down with the simple information D2 having a small amount of information (smaller data size) and then acquiring only a small number of the detailed information D1 having a large amount of information (larger data size), the load of the search processing in each of the DB2 and DB3 and the load of the network N between each of the DB2 and DB3 and the terminal device 4 can be reduced.

[0024] (Functional Configuration of Terminal Device) Figure 2 shows the functional configuration of a terminal device according to one embodiment. As shown in Figure 2, the terminal device 4 includes a processor 41, memory 42, storage 43, input / output interface 44, and communication interface 45.

[0025] Memory 42 has a memory area necessary for the operation of the processor 41.

[0026] The storage 43 is a so-called auxiliary storage device, such as an HDD (Hard Disk Drive) or SSD (Solid State Drive). The storage 43 stores data that each part of the processor 41 acquires, generates, and references during processing.

[0027] The input / output interface 44 is a connection interface for connecting to devices such as a display device 46 and an input device 47. The display device 46 is a monitor such as a liquid crystal display. The input device 47 is an input device such as a keyboard or mouse. Note that the display device 46 and the input device 47 may be an integrated device such as a touch panel.

[0028] The communication interface 45 is an interface for sending and receiving various data and control signals between the detailed information DB2 and the simplified information DB3 (metadata DB31, thumbnail DB32).

[0029] The processor 41 operates according to a predetermined program, performing functions as a condition acquisition unit 411, a simplified information acquisition unit 412, and a detailed information acquisition unit 413.

[0030] The condition acquisition unit 411 acquires search conditions for searching for vehicle information (detailed information D1, simplified information D2). The search conditions are specified by the user via the input device 47.

[0031] The simplified information acquisition unit 412 acquires simplified information D2 that matches the search criteria from the simplified information DB3.

[0032] The detailed information acquisition unit 413 selects at least one of the acquired simplified information D2s and obtains the detailed information D1 corresponding to the selected simplified information D2 from the detailed information DB2.

[0033] The predetermined program executed by the processor 41 is stored on a computer-readable recording medium. A computer-readable recording medium refers to a magnetic disk, magneto-optical disk, CD-ROM, DVD-ROM, semiconductor memory, etc. Alternatively, this computer program may be distributed to a computer via a communication line, and the computer that receives the distribution may execute the program. Furthermore, this program may be intended to implement only a part of the functions described above. Moreover, it may be a program that can implement the above functions in combination with a program already recorded in the computer system, a so-called differential file (differential program).

[0034] (Recording of detailed and simplified information) Figure 3 is a sequence diagram showing an example of the recording process for detailed and simplified information according to one embodiment. Figure 4 shows an example of detailed information and simplified information according to one embodiment. Here, we will explain the process of recording detailed and simplified information, referring to Figures 3 and 4.

[0035] First, when a vehicle approaches the tollbooth, the license plate reader 51 and sensor 52 of the roadside device 5 acquire the vehicle's license plate information and sensor information, respectively (step S101).

[0036] Furthermore, the roadside device 5 transmits processing result information, including the image (high-resolution image) and the read license plate information captured by the license plate reader 51, and sensor information acquired by the sensor 52 (for example, information indicating the vehicle's lane), to the detailed information DB2 (step S102).

[0037] The detailed information DB2 records detailed information D1, which includes the image and processing result information received from the roadside device 5 (step S103). As shown in Figure 4, detailed information D1 is the image D12 and processing result information D13 received from the roadside device 5, with index D11 attached. The processing result information D13 includes the license plate information read by the license plate reader 51, the date and time (processing date and time) and location where the reading process was performed, and sensor information acquired by the sensor 52. The location where the reading process was performed is information that can identify the installation location of the license plate reader 51 (for example, the toll booth ID of the toll booth where it is installed).

[0038] Next, the detailed information DB2 generates simplified information D2 from the detailed information D1 and sends it to the simplified information DB3. For example, the detailed information DB2 generates metadata D2a, which includes the processing result information D13 (text information) of the detailed information D1, as simplified information D2 and sends it to the metadata DB31 (step S104). Metadata D2a includes index D23 and processing result information D24. Index D23 of metadata D2a is the same as index D11 of detailed information D1. Processing result information D24 of metadata D2a includes at least the processing date and time, location, and license plate information from the processing result information D13 of detailed information D1. Processing result information D24 of metadata D2a may further include sensor information from the processing result information D13 of detailed information D1. The metadata DB31 records the metadata D2a received from the detailed information DB2 (step S105).

[0039] Furthermore, the detailed information DB2 generates thumbnail information D2b as simplified information D2, which includes a thumbnail D22 that is a reduced-size version of the high-resolution image D12, and sends it to the thumbnail DB32 (step S106). The thumbnail information D2b includes index D21 and thumbnail D22. Index D21 of thumbnail information D2b is the same as index D11 of detailed information D1. The thumbnail DB32 records the thumbnail information D2b received from the detailed information DB2 (step S107).

[0040] The search system 1 executes the series of processes shown in Figure 3 each time it acquires new information from the roadside device 5. Note that Figure 3 shows an example where the detailed information DB2 generates simplified information D2 each time it records detailed information D1, but it is not limited to this. In other embodiments, the detailed information DB2 may store the detailed information D1 collected from the roadside device 5 and, at a predetermined timing, perform a batch process to convert multiple detailed information D1s into metadata D2a and thumbnail information D2b and transmit them. The predetermined timing could be, for example, after a certain period of time has elapsed or after a certain amount of data has been accumulated. Alternatively, the predetermined timing could be when no other high-load processes are running and there is sufficient processing resources available (for example, when the resources used by other processes are less than X%).

[0041] (Search process) Figure 5 is a sequence diagram showing an example of a search process according to one embodiment. The following describes the search process flow in search system 1, with reference to Figure 5.

[0042] Let's consider an example of searching for a target vehicle. The user inputs search conditions for this target vehicle into the search system 1 via the input device 47 of the terminal device 4 and presses the search button. The condition acquisition unit 411 of the terminal device 4 then acquires the search conditions entered by the user (step S201). For example, suppose the user is searching for a target vehicle that passed through a certain toll booth during a certain period (for example, from 10:00 to 12:00 on January 15th). In this case, the user inputs information indicating the location of the toll booth (toll booth ID) and the period as search conditions. In other embodiments, the search conditions may not be manually specified by the user, but may be automatically specified by another system that is linked to the system. For example, the other system may be a violation monitoring system that automatically generates search conditions based on the detection location and detection date and time of the violating vehicle and specifies them to the terminal device 4.

[0043] Next, the simplified information acquisition unit 412 of the terminal device 4 acquires simplified information D2 that matches the search conditions from the simplified information DB3. In this embodiment, the simplified information acquisition unit 412 first requests the metadata DB31 to search for metadata D2a that matches the search conditions (step S202).

[0044] The metadata DB31 searches for metadata D2a that matches the search criteria from among multiple metadata D2a and transmits it to the terminal device 4 (step S203). In the example above, the metadata DB31 searches for metadata D2a in which the "location" of the processing result information D24 matches the location (tollbooth ID) specified in the search criteria and the "processing date and time" is included in the period specified in the search criteria, and transmits it to the terminal device 4. Since metadata D2a is small data containing only text information, even if there are multiple specified locations or the period is long and the search range is wide, the load and processing time of the search process will be relatively small compared to the case of searching for high-resolution images D12 included in detailed information D1. Also, since the data size of metadata D2a is smaller than that of high-resolution images D12, even if there are many metadata D2a that match the search criteria, the load on the network N will also be small.

[0045] When the simplified information acquisition unit 412 of the terminal device 4 receives metadata D2a from the metadata DB 31, it displays it on the display device 46. At this time, the simplified information acquisition unit 412 may display multiple received metadata D2a in list format.

[0046] Next, the user selects and specifies the information from the metadata D2a displayed on the display device 46 that applies to the vehicle being searched. When the terminal device 4's simplified information acquisition unit 412 receives the user's selection (step S205), it requests thumbnail information D2b corresponding to the selected metadata D2a from the thumbnail DB 32 (step S206). For example, if the vehicle being searched for is a passenger car, the user selects only the metadata D2a containing license plate information (classification number) corresponding to a passenger car using checkboxes, etc., and presses the thumbnail acquisition button. Multiple pieces of metadata D2a may be selected. Then, the terminal device 4's simplified information acquisition unit 412 specifies the index D23 of the metadata D2a selected by the user and requests the thumbnail DB 32 to send thumbnail information D2b that matches this index.

[0047] The thumbnail DB32 reads thumbnail information D2b having the same index D21 as the index requested by the terminal device 4 and transmits it to the terminal device 4 (step S207). In this way, since filtering has been done in advance with metadata D2a, the thumbnail DB32 only needs to read thumbnail information D2b corresponding to the requested index. Therefore, the thumbnail DB32 does not need to perform image search processing, which reduces processing load and processing time. In addition, the data size of thumbnail information D2b (thumbnail D22) is smaller than the high-resolution image D12 of detailed information D1, so the load on the network N is also reduced.

[0048] The simplified information acquisition unit 412 of the terminal device 4 displays the thumbnail information D2b acquired from the thumbnail DB 32 on the display device 46 (step S208).

[0049] Next, the user selects and specifies the information that applies to the vehicle being searched from the thumbnail information D2b displayed on the display device 46. When the detailed information acquisition unit 413 of the terminal device 4 receives the user's selection (step S209), it requests detailed information D1 corresponding to the selected thumbnail information D2b from the detailed information DB2 (step S210). For example, the user refers to the thumbnail information D2b and selects the thumbnail information D2b that includes a thumbnail D22 that matches the characteristics of the vehicle being searched, such as its color and shape, using checkboxes or other means, and then presses the detailed information acquisition button. Multiple thumbnail information D2b may be selected. In this case, the detailed information acquisition unit 413 of the terminal device 4 specifies the index D21 of the thumbnail information D2b selected by the user and requests the detailed information DB2 to send detailed information D1 that matches this index.

[0050] The detailed information DB2 reads detailed information D1 that has the same index D11 as the index requested by the terminal device 4 and sends it to the terminal device 4 (step S211). In this way, since filtering has been done in advance using metadata D2a and thumbnail information D2b, the detailed information DB2 only needs to read the detailed information D1 corresponding to the requested index. Therefore, the detailed information DB2 does not need to perform a search process for the high-resolution image D12, thus reducing the processing load and processing time. In addition, because the detailed information D1 that the terminal device 4 requests from the detailed information DB2 is filtered in advance, the detailed information DB2 can be prevented from sending a large number of detailed information D1 to the terminal device 4. This also reduces the load on the network N.

[0051] The detailed information acquisition unit 413 of the terminal device 4 displays the detailed information D1 obtained from the detailed information DB2 on the display device 46 (step S212). The user can refer to the detailed information D1 to find out the license plate information of the vehicle being searched.

[0052] For example, in step S204, if there are too many metadata entries D2a or if the displayed metadata entries D2a do not include the vehicle being searched for, the user may change (re-enter) the search conditions and re-search for metadata entries D2a (re-execute steps S201-S203). Similarly, in step S208, if the displayed thumbnails do not include the vehicle being searched for, the user may change the selected metadata entries D2a and re-acquire thumbnail information D2b (re-execute steps S205-S207). By doing so, the number of transmissions of detailed information D1 from detailed information DB2 to terminal device 4 can be minimized, thereby further reducing the load on network N.

[0053] Furthermore, although this embodiment describes an example in which the simplified information DB3 has metadata DB31 and thumbnail DB32 separately, it is not limited to this. In other embodiments, the simplified information DB3 may have only one of metadata DB31 or thumbnail DB32. If the simplified information DB3 has only thumbnail DB32, thumbnail DB32 has a function (image search function) that allows searching for thumbnails D22 that match the search criteria. This image search function may utilize known technology. In yet another embodiment, the simplified information DB3 may consist of a single database that allows searching for both metadata D2a and thumbnail information D2b.

[0054] (Effect, Action) As described above, the search system 1 according to this embodiment includes a detailed information DB2 that collects detailed information D1 from a license plate reader 51, which includes an image D12 (high-resolution image) of a license plate and processing result information D13 that includes license plate information read from the image D12; a simplified information DB3 that stores simplified information D2 which has less information than the detailed information D1; and a terminal device 4 that acquires simplified information D2 and detailed information D1 that match the search conditions specified by the user from the simplified information DB3 and the detailed information DB2. The terminal device 4 includes a simplified information acquisition unit 412 that acquires simplified information D2 that matches the search conditions from the simplified information DB3, and a detailed information acquisition unit 413 that selects at least one of the acquired simplified information D2 and acquires detailed information D1 corresponding to the selected simplified information D2 from the detailed information DB2.

[0055] In this way, the search system 1 can perform searches and refinements using the simplified information D2, which contains less information, and then pinpoint and retrieve the detailed information D1, which contains more information. This reduces the amount of data transmitted from the detailed information DB2 to the terminal device 4, thereby reducing the load on the network N. Furthermore, even if the detailed information DB2 is performing other priority processing and the service of providing detailed information D1 is temporarily unavailable, the search system 1 can continue the search and refinement process of the simplified information D2 between the terminal device 4 and the simplified information DB3. Moreover, even if a failure occurs in the network N between the detailed information DB2 and the terminal device 4, for example, the search and refinement process of the simplified information D2 can be continued. In other words, the search system 1 can improve the continuity of the search service with the above configuration.

[0056] Furthermore, the simplified information DB3 has a metadata DB31 that records metadata D2a, which is text information including license plate information.

[0057] In this way, the metadata DB31 only needs to search for metadata D2a, which has a smaller data size than the detailed information D1, thus significantly reducing the processing load and processing time compared to the search process for detailed information D1. Furthermore, the amount of data transmitted from the metadata DB31 to the terminal device 4 can also be reduced, thus reducing the load on the network N.

[0058] Furthermore, the simplified information DB3 has a thumbnail DB32 that records thumbnail information D2b, which includes a thumbnail D22 obtained by reducing the high-resolution image D12 of the detailed information D1.

[0059] In this way, the thumbnail DB32 only needs to search for thumbnail information D2b, which has a smaller data size than detailed information D1, thus significantly reducing the processing load and processing time compared to the search process for detailed information D1. Furthermore, the amount of data transmitted from the thumbnail DB32 to the terminal device 4 can also be reduced, thus reducing the load on the network N.

[0060] Furthermore, the simplified information DB3 may contain both the metadata DB31 and the thumbnail DB32. In this case, the simplified information acquisition unit 412 of the terminal device 4 acquires metadata D2a that matches the search criteria from the metadata DB31, selects at least one of the acquired metadata D2a, and acquires thumbnail information D2b corresponding to the selected metadata D2a from the thumbnail DB32. The detailed information acquisition unit 413 of the terminal device 4 acquires detailed information D1 corresponding to the thumbnail information D2b from the detailed information DB2.

[0061] In this way, users of search system 1 can determine the suitability of their search conditions based on both metadata D2a and thumbnail information D2b. Both metadata D2a and thumbnail information D2b have smaller data sizes than detailed information D1, resulting in less load on the search process and the network N. Therefore, search system 1 can provide users with simplified information D2 with low load even when multiple searches are attempted with different search conditions. Consequently, even if the search conditions are not sufficiently narrowed down at the start of the search, users can appropriately search for target vehicles by attempting multiple searches. Furthermore, metadata D2a, which contains only text information, has a smaller data size than thumbnail information D2b, which contains images (thumbnails D22). Therefore, since it is only necessary to narrow down and select using metadata D2a and then specify and retrieve the thumbnail information D2b corresponding to metadata D2a, thumbnail DB32 does not need to perform image search processing and can provide thumbnail information D2b to terminal device 4 at high speed. Furthermore, since the amount of data transmitted from the thumbnail DB32 to the terminal device 4 can be reduced, the load on the network N can be further reduced.

[0062] As described above, embodiments relating to this disclosure have been explained, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0063] <Note> The search system and search method described in the above-described embodiment can be understood, for example, as follows:

[0064] (1) According to the first embodiment, the search system 1 includes a detailed information database 2 that collects detailed information D1 from a plurality of license plate readers 51 that read the license plates of vehicles, which includes an image D12 of a license plate and processing result information D13 that includes license plate information read from the image D12; a simplified information database 3 that stores simplified information D2 which is generated from the same image D12 as the image D12 included in the detailed information D1, but has less information than the detailed information D1; and a terminal device 4 that obtains simplified information D2 and detailed information D1 that match the specified search conditions from the simplified information database 3 and the detailed information database 2. The terminal device 4 includes a simplified information acquisition unit 412 that obtains simplified information D2 that match the search conditions from the simplified information database 3, and a detailed information acquisition unit 413 that selects at least one of the acquired simplified information D2 and obtains detailed information D1 corresponding to the selected simplified information D2 from the detailed information database 2.

[0065] In this way, the search system 1 can perform searches and refinements using the simplified information D2, which contains less information, and then pinpoint and retrieve the detailed information D1, which contains more information. This reduces the amount of data transmitted from the detailed information DB2 to the terminal device 4, thereby reducing the load on the network N. Furthermore, even if the detailed information DB2 is performing other priority processing and the service of providing detailed information D1 is temporarily unavailable, the search system 1 can continue the search and refinement process of the simplified information D2 between the terminal device 4 and the simplified information DB3. Moreover, even if a failure occurs in the network N between the detailed information DB2 and the terminal device 4, for example, the search and refinement process of the simplified information D2 can be continued. In other words, the search system 1 can improve the continuity of the search service with the above configuration.

[0066] (2) According to the second embodiment, in the search system 1 according to the first embodiment, the simplified information database 3 has a metadata database 31 that records metadata D2a, which is text information including license plate information.

[0067] In this way, the metadata DB31 only needs to search for metadata D2a, which has a smaller data size than the detailed information D1, thus significantly reducing the processing load and processing time compared to the search process for detailed information D1. Furthermore, the amount of data transmitted from the metadata DB31 to the terminal device 4 can also be reduced, thus reducing the load on the network N.

[0068] (3) According to the third embodiment, in the search system 1 according to the first or second embodiment, the simplified information database 3 has a thumbnail database 32 that records thumbnail information D2b including a thumbnail D22 which is a reduced version of the image D12.

[0069] In this way, the thumbnail DB32 only needs to search for thumbnail information D2b, which has a smaller data size than detailed information D1, thus significantly reducing the processing load and processing time compared to the search process for detailed information D1. Furthermore, the amount of data transmitted from the thumbnail DB32 to the terminal device 4 can also be reduced, thus reducing the load on the network N.

[0070] (4) According to the fourth aspect, in the search system 1 according to the first aspect, the simplified information database 3 has a metadata database 31 that records metadata D2a which is text information including license plate information, and a thumbnail database 32 that records thumbnail information D2b which is a thumbnail D22 which is a reduced image D12. The simplified information acquisition unit 412 of the terminal device 4 acquires metadata D2a that matches the search conditions from the metadata database 31, selects at least one of the acquired metadata D2a, and acquires thumbnail information D2b corresponding to the selected metadata D2a from the thumbnail database 32. The detailed information acquisition unit 413 of the terminal device 4 acquires detailed information D1 corresponding to the thumbnail information D2b from the detailed information database 2.

[0071] In this way, users of search system 1 can determine the suitability of their search conditions based on both metadata D2a and thumbnail information D2b. Both metadata D2a and thumbnail information D2b have smaller data sizes than detailed information D1, resulting in less load on the search process and the network N. Therefore, search system 1 can provide users with simplified information D2 with low load even when multiple searches are attempted with different search conditions. Consequently, even if the search conditions are not sufficiently narrowed down at the start of the search, users can appropriately search for target vehicles by attempting multiple searches. Furthermore, metadata D2a, which contains only text information, has a smaller data size than thumbnail information D2b, which contains images (thumbnails D22). Therefore, since it is only necessary to narrow down and select using metadata D2a and then specify and retrieve the thumbnail information D2b corresponding to metadata D2a, thumbnail DB32 does not need to perform image search processing and can provide thumbnail information D2b to terminal device 4 at high speed. Furthermore, since the amount of data transmitted from the thumbnail DB32 to the terminal device 4 can be reduced, the load on the network N can be further reduced.

[0072] (5) According to the fifth aspect, the search method is a search method using a search system 1 comprising: a detailed information database 2 that collects detailed information D1 including an image D12 of a license plate and processing result information D13 including license plate information read from the image D12 from a plurality of license plate readers 51 that read the license plates of vehicles; a simplified information database 3 that stores simplified information D2 which is generated from the same image D12 as the image D12 included in the detailed information D1 and has a smaller amount of information than the detailed information D1; and a terminal device 4 that obtains simplified information D2 and detailed information D1 that match the specified search conditions from the simplified information database 3 and the detailed information database 2, wherein the terminal device 4 obtains simplified information D2 that match the search conditions from the simplified information database 3; and the terminal device 4 selects at least one of the obtained simplified information D2 and obtains detailed information D1 corresponding to the selected simplified information D2 from the detailed information database 2. [Explanation of Symbols]

[0073] 1. Search System 2. Detailed Information Database (DB) 3. Simple Information Database (DB) 31. Metadata Database (DB) 32 Thumbnail Database (DB) 4 Terminal devices 41 processors 411 Condition Acquisition Unit 412 Simple information acquisition part 413 Detailed information acquisition section 42 memory 43 Storage 44 Input / Output Interfaces 45 Communication Interface 46 Display device 47 Input devices 5 Roadside equipment 51 License plate reader 52 sensors 110 processors D1 Detailed Information D2 Simple information D2a Meta Information D2b Thumbnail Information N Network

Claims

1. A detailed information database that collects and stores detailed information including images of license plates and processing result information including license plate information read from the images from multiple license plate readers that read vehicle license plates, and automatically generates simplified information which is generated from the same images as the images included in the detailed information and has less information than the detailed information, from multiple license plate readers that read vehicle license plates, A simplified information database that stores the simplified information generated by the detailed information database, A terminal device that obtains the simplified information and detailed information matching the specified search criteria from the simplified information database and the detailed information database, Equipped with, The aforementioned terminal device is A simplified information acquisition unit that acquires simplified information matching the aforementioned search criteria from the simplified information database, A detailed information acquisition unit selects at least one of the acquired simplified information and obtains detailed information corresponding to the selected simplified information from the detailed information database. Having, Search system.

2. The aforementioned simplified information database has a metadata database that records metadata, which is text information including the license plate information. The search system according to claim 1.

3. The aforementioned simplified information database includes a thumbnail database that records thumbnail information, including thumbnails of the aforementioned images. The search system according to claim 1 or 2.

4. The aforementioned simplified information database includes a metadata database that records metadata, which is text information including the license plate information, and a thumbnail database that records thumbnail information, which includes thumbnails of the image reduced in size. The simplified information acquisition unit of the terminal device acquires metadata that matches the search criteria from the metadata database, selects at least one of the acquired metadata, and acquires thumbnail information corresponding to the selected metadata from the thumbnail database. The detailed information acquisition unit of the terminal device acquires detailed information corresponding to the thumbnail information from the detailed information database. The search system according to claim 1.

5. A detailed information database that collects detailed information from a plurality of license plate readers that read the license plates of vehicles, including an image of the license plate and processing result information including license plate information read from the image, A simplified information database that stores simplified information, which is generated from the same image as the image included in the detailed information, but has less information than the detailed information; A terminal device that obtains the simplified information and detailed information matching the specified search criteria from the simplified information database and the detailed information database, Equipped with, The aforementioned terminal device is A simplified information acquisition unit that acquires simplified information matching the aforementioned search criteria from the simplified information database, A detailed information acquisition unit selects at least one of the acquired simplified information and obtains detailed information corresponding to the selected simplified information from the detailed information database. It has, The aforementioned simplified information database includes a metadata database that records metadata, which is text information including the license plate information, and a thumbnail database that records thumbnail information, which includes thumbnails of the image reduced in size. The simplified information acquisition unit of the terminal device acquires metadata that matches the search criteria from the metadata database, selects at least one of the acquired metadata, and acquires thumbnail information corresponding to the selected metadata from the thumbnail database. The detailed information acquisition unit of the terminal device acquires detailed information corresponding to the thumbnail information from the detailed information database. Search system.

6. A detailed information database that collects and stores detailed information including images of license plates and processing result information including license plate information read from the images from multiple license plate readers that read vehicle license plates, and automatically generates simplified information which is generated from the same images as the images included in the detailed information and has less information than the detailed information, from multiple license plate readers that read vehicle license plates, A simplified information database that stores the simplified information generated by the detailed information database, A terminal device that obtains the simplified information and detailed information matching the specified search criteria from the simplified information database and the detailed information database, A search method using a search system comprising: The terminal device obtains simplified information matching the search criteria from the simplified information database. The terminal device selects at least one of the acquired simplified information and obtains detailed information corresponding to the selected simplified information from the detailed information database. A search method that has [a certain feature].

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