JP6941212B2 - Image analysis system, image analysis method, and image analysis program - Google Patents

Description

The present disclosure relates to an image analysis system, an image analysis method, and an image analysis program.

Global navigation satellite system (as a means of providing position information in various fields such as surveying, civil engineering construction, agriculture, earthquake prediction, and crustal movement research, which require highly accurate positioning, as well as car navigation systems. GNSS: Global Navigation Satellite System) is used.

In GNSS, a GNSS antenna installed on the earth performs positioning by receiving GNSS signals from at least four positioning satellites orbiting the earth. It is necessary to constantly observe the GNSS signal in order to perform high-precision positioning, and if there is a shield such as a building or a tree between the GNSS antenna and the positioning satellite, the positioning accuracy deteriorates.

Therefore, the installation position of the GNSS antenna becomes very important for highly accurate positioning. However, since the positioning satellite is constantly orbiting the earth, it is necessary to keep capturing the positioning satellite for at least 24 hours in order to evaluate the reception status of the GNSS antenna. Therefore, it takes a very long time to evaluate only one installation position, and it takes an enormous amount of time to determine the installation positions of several hundreds or more, for example, to install them in various places.

The present application has been made in view of the above, and an object of the present application is to provide an image analysis system, an image analysis method, and an image analysis program capable of evaluating the reception status of a GNSS antenna in a shorter time.

The image analysis system according to the present application is a photographing camera that acquires a sky moving image at a first point, and a terminal device that acquires a sky moving image from the photographing camera and acquires a frame after a lapse of a predetermined time from the start of the sky moving image as a sky image. Then, the sky image is acquired from the terminal device, and the sky image is filtered to extract the sky part included in the sky image, and the reception status of the GNSS antenna that receives the signal from the GNSS is evaluated. It is characterized by being equipped with an image analysis device that calculates an index value.

According to one aspect of the embodiment, the reception status of the GNSS antenna can be evaluated in a shorter time.

FIG. 1 is a diagram showing a configuration example of an information processing system 1 for performing an RTK positioning method. FIG. 2 is a diagram showing a configuration example of the image analysis system according to the embodiment. FIG. 3 is a diagram showing a functional configuration example of the terminal device 100 according to the embodiment. FIG. 4 is a diagram showing an example of information stored in the analysis result storage unit. FIG. 5 is a diagram showing a functional configuration example of the image analysis device 200 according to the embodiment. FIG. 6 is a diagram showing an example of a sky image according to the embodiment. FIG. 7 is a diagram showing an example of image processing for extracting an empty portion according to the embodiment. FIG. 8 is a diagram showing an example of a histogram for the binarization process according to the embodiment. FIG. 9 is a diagram showing an example of a region excluded from the analysis target according to the embodiment. FIG. 10 is a diagram showing an example of a horizontal region excluded from the analysis target according to the embodiment. FIG. 11 is a diagram showing an example of the original image and each processed image according to the embodiment. FIG. 12 is a diagram showing an example of a composite image of the sky image and the satellite orbit according to the embodiment. FIG. 13 is a diagram showing an example of an analysis result screen of the analysis application according to the embodiment. FIG. 14 is a flowchart showing the flow of image analysis processing for the sky image according to the embodiment. FIG. 15 is a hardware configuration diagram showing an example of a computer that realizes the function of the image analysis device.

Hereinafter, the image analysis system, the image analysis method, and the mode for carrying out the image analysis program (hereinafter referred to as “the embodiment”) according to the present application will be described in detail with reference to the drawings. Note that this embodiment does not limit the image analysis system, the image analysis method, and the image analysis program according to the present application. Further, in each of the following embodiments, the same parts are designated by the same reference numerals, and duplicate description is omitted.

First, before explaining the present embodiment, a GNSS antenna capable of evaluating the reception status in a shorter time by the present embodiment will be described. The GNSS antenna is mounted on a reference station whose installation position is known in advance, and is used for real-time correction of position information of, for example, an automobile. For example, when only the position information from the GNSS receiver mounted on the vehicle is used (single positioning method; one GNSS receiver simultaneously receives GNSS signals from multiple positioning satellites and calculates the distance from each GNSS satellite. Positioning method), at present, there may be an error of several meters in the position information. Therefore, it is considered to correct such an error of position information in real time by using a reference station equipped with a GNSS antenna (such a method is called a Real Time Kinematic (RTK) positioning method).

<< About RTK positioning method >>
FIG. 1 is a diagram showing a configuration example of an information processing system 1 for performing an RTK positioning method. As shown in FIG. 1, the information processing system 1 can include a mobile station 5 (not shown) mounted on the automobile 6, a server 2, a reference station 3, and a GNSS positioning satellite 4.

In the RTK positioning method, GNSS positioning is performed by a plurality of reference stations 3 whose installation positions are grasped in advance and mobile stations 5 located in the vicinity of an automobile 6 (specifically, a mobile station 5) for which a position is to be obtained. Receives GNSS signals from satellite 4. Next, in the positioning method, the reference station 3 transmits the position information of the reference station 3 acquired by the reference station 3 to the server 2 or the mobile station 5 in real time. Then, the server 2 or the mobile station 5 uses the position information of the reference station 3 to correct the temporary position information of the automobile 6 acquired by the mobile station 5 in real time. According to the RTK positioning method, it is possible to cancel the error caused by the disturbance due to the ionosphere, multipath, clock deviation, etc. caused by the GNSS signal by performing the above correction, so that the error is several centimeters. It can be suppressed to about a meter. As a result, according to the positioning method, it becomes easy to acquire the position information of the automobile 6 with a small error.

The RTK positioning method can be mainly divided into two methods: a server RTK positioning method in which the server 2 makes corrections, and a device RTK positioning method in which corrections are made by the mobile station 5.

<Device RTK positioning method>
The mobile station 5 receives GSNN signals from each of at least three or four or more GNSS positioning satellites 4. Next, the mobile station 5 uses the information contained in each GNSS signal (position information and time information of each GNSS positioning satellite 4) to provide provisional position information of the automobile 6 (specifically, the mobile station 5 on the ground). Latitude / longitude information) is acquired. Further, the mobile station 5 transmits the acquired temporary position information of the automobile 6 to the server 2.

The reference station 3 receives the GSNN signal from each of the plurality of GNSS positioning satellites 4 in response to the distribution request from the server 2. Next, the reference station 3 obtains the position information of the reference station 3 (specifically, the latitude and longitude information of the reference station 3 on the ground) based on the information contained in each GNSS signal (position information and time information of each GNSS positioning satellite 4). get. Further, the reference station 3 transmits the acquired position information of the reference station 3 to the server 2.

The server 2 acquires the provisional position information of the automobile 6 from the mobile station 5 and the position information of the reference station 3 from the reference station 3. Next, the server 2 has the position information of the installation position of each reference station 3 (specifically, the latitude and longitude information of the reference station 3 on the ground) stored in advance in the storage unit 260, and the position information received from the reference station 3. Based on the difference, correction information for correction with respect to the provisional position information of the automobile 6 is generated. Further, the server 2 corrects the provisional position information of the automobile 6 based on the generated correction information.

<Server RTK positioning method>
The mobile station 5 receives GSNN signals from each of at least three or four or more GNSS positioning satellites 4. Next, the mobile station 5 uses the information contained in each GNSS signal (position information and time information of each GNSS positioning satellite 4) to provide provisional position information of the automobile 6 (specifically, the mobile station 5 on the ground). Latitude / longitude information) is acquired. Further, the mobile station 5 transmits the acquired temporary position information of the automobile 6 to the server 2.

The reference station 3 receives the GSNN signal from each of the plurality of GNSS positioning satellites 4 in response to the distribution request from the server 2. Next, the reference station 3 obtains the position information of the reference station 3 (specifically, the latitude and longitude information of the reference station 3 on the ground) based on the information contained in each GNSS signal (position information and time information of each GNSS positioning satellite 4). get. Further, the reference station 3 transmits the acquired position information of the reference station 3 to the server 2.

The server 2 acquires the provisional position information of the automobile 6 from the mobile station 5 and the position information of the reference station 3 from the reference station 3. The server 2 generates correction information for correction with respect to the provisional position information of the automobile 6 based on the difference between the position information of the installation position of each reference station 3 and the position information of the reference station 3 received from the reference station 3. Further, the server 2 transmits the generated correction information to the mobile station 5.

The mobile station 5 receives the correction information from the server 2. The mobile station 5 corrects the acquired provisional position information of the automobile 6 based on the received correction information.

In order to determine the installation position of the GNSS antenna mounted on the reference station 3 for performing the RTK positioning method as described above, it is necessary to evaluate the reception status of the GNSS antenna. Hereinafter, the present embodiment capable of evaluating the reception status of the GNSS antenna in a shorter time will be described.

[1. Image analysis system configuration]
The configuration of the image analysis system will be described with reference to FIG. FIG. 2 is a diagram showing a configuration example of the image analysis system according to the embodiment. As shown in FIG. 2, the image analysis system includes a photographing camera 10, a terminal device 100, and an image analysis device 200. As shown in FIG. 2, the terminal device 100 and the image analysis device 200 are connected to each other so as to be able to communicate with each other via the network N. As the network N, various communication networks such as the Internet can be adopted regardless of whether it is wired or wireless. Further, the terminal device 100 is connected to the photographing camera 10 by a communication cable 50 so as to be able to communicate with each other. The communication cable 50 is, for example, a USB cable, but the communication between the terminal device 100 and the photographing camera 10 may be wired or wireless. Alternatively, the photographing camera 10 may be a type of camera that is directly connected to the external connection terminal of the terminal device 100. In this case, the communication cable 50 is unnecessary. During the shooting of the shooting camera 10, the shooting camera 10 does not need to be connected to the terminal device 100, and is connected to the terminal device 100 in order to acquire the sky moving image shot by the shooting camera 10.

The photographing camera 10 is a 360-degree camera for taking a sky photograph. The photographing camera 10 is installed on a camera tripod, for example, so that the lens on one side for photographing 180 degrees faces the sky. The lens on the other side facing the ground is covered with tape so that nothing is reflected. As a result, the sky can be photographed from the photographing camera 10. The camera tripod is not always necessary, and the photographing camera 10 may be installed at the receiving position of the GNSS antenna. The photographing camera 10 photographs the sky for a certain period of time and acquires a sky moving image. The start and end of shooting are performed, for example, by the user pressing the shooting button of the shooting camera 10.

The terminal device 100 is a terminal used by the user. The user is, for example, a worker of a telecommunications carrier who takes a sky photograph and analyzes it. The terminal device 100 may be a mobile terminal such as a smartphone or a tablet PC, or may be a stationary terminal installed in a user's company or the like. An analysis application for analyzing a sky photograph (image) is installed in the terminal device 100, and the user can operate the analysis application to proceed with the analysis of the sky image. The analysis process for the sky image will be described later.

The image analysis device 200 is, for example, a server device managed by a telecommunications carrier. The image analysis device 200 calculates the ratio of the sky (sky opening ratio) and the PDOP (Positron Division Of Precision) value by performing image processing on the sky image, and transmits the analysis result to the terminal device 100. The sky opening ratio is an index value indicating the ratio of the sky portion in the sky image. When there are few obstacles and the sky can be seen sufficiently, the sky opening rate tends to be high and the positioning accuracy tends to be high. The PDOP value is an index value indicating the arrangement state of the positioning satellite. When the positioning satellites are evenly and evenly arranged in the sky, the PDOP value tends to be low and the positioning accuracy tends to be high. The image analysis device 200 may be a cloud server device or a distributed computing system composed of a plurality of computers.

[2. Configuration of terminal device 100]
Next, the functional configuration of the terminal device 100 according to the embodiment will be described with reference to FIG. FIG. 3 is a diagram showing a functional configuration example of the terminal device 100 according to the embodiment. As shown in FIG. 3, the terminal device 100 includes a communication unit 110, a storage unit 120, and a control unit 130. The terminal device 100 is an input device (for example, a keyboard, a mouse, a touch panel) that receives various operations from a user or the like who uses the terminal device 100, and an output device (for example, a liquid crystal display or a touch panel) for displaying various information. May have.

(Communication unit 110)
The communication unit 110 is realized by, for example, a NIC (Network Interface Card) or the like. The communication unit 110 is connected to the network N by wire or wirelessly, and transmits / receives information to / from the image analysis device 200 and the photographing camera 10 via the network N.

(Memory unit 120)
The storage unit 120 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory (Flash Memory), or a storage device such as a hard disk or an optical disk. As shown in FIG. 3, the storage unit 120 includes a sky moving image storage unit 121, a sky image storage unit 122, and an analysis result storage unit 123. Hereinafter, each storage unit included in the storage unit 120 will be described in order.

(Sky video storage unit 121)
The sky moving image storage unit 121 stores the sky moving image taken by the photographing camera 10. In the sky movie, the shooting point (latitude, longitude) etc. can be specified by the file name or the like.

(Sky image storage unit 122)
The sky image storage unit 122 stores the sky image acquired from the sky moving image. As for the sky image, the shooting point and the sky movie of the acquisition source can be specified by the file name or the like.

(Analysis result storage unit 123)
The analysis result storage unit 123 stores information regarding the analysis result of the sky image based on the sky opening ratio and the PDOP value. FIG. 4 is a diagram showing an example of information stored in the analysis result storage unit. In the example shown in FIG. 4, the analysis result storage unit 123 stores "sky image ID, sky opening ratio, aperture ratio result, PDOP, PDOP result, antenna ID" and the like in association with each other.

The "sky image ID" is an identifier (for example, a file name) that uniquely indicates the analyzed sky image. The "sky aperture ratio" is, for example, an index value indicating the ratio (%) of the sky portion included in the target sky image. The "opening rate result" is a judgment result for the sky opening rate. For example, when the "sky aperture ratio" is equal to or higher than a predetermined threshold value, the sky can be sufficiently seen from the shooting point, and it can be determined that "OK" is appropriate as the reception position of the GNSS antenna.

Here, the PDOP value is an index value indicating the arrangement state of the positioning satellite, and the higher the positioning accuracy, the smaller the value. For example, even if the number of positioning satellites is large, if they are unevenly arranged only in a certain direction, the positioning accuracy will be low and the PDOP value will be high. On the contrary, if the positioning satellites are evenly and evenly arranged in the sky, the positioning accuracy becomes high and the PDOP value shows a low value. The image analysis device 200 has orbit data of each positioning satellite, and by superimposing the orbit data on the processed image extracted from the empty part, the arrangement state of each positioning satellite can be grasped. The PDOP value can be calculated. Since the PDOP value is a value indicating the arrangement state of the positioning satellite at a certain time, for example, 24 hours is calculated in units of 30 minutes or 1 hour.

“PDOP” is, for example, the ratio (%) of the PDOP value indicating high accuracy among the PDOP values for 24 hours. In this way, using the ratio of the PDOP value as a criterion indicates, for example, that the PDOP value has high accuracy for several hours out of 24 hours, and the positioning accuracy is low at other times. This is because it cannot be said that the reception position of the GNSS antenna is appropriate. The "PDOP result" is a determination result for PDOP. For example, when "PDOP" is equal to or higher than a predetermined threshold value, the GNSS antenna can sufficiently maintain high-precision positioning and can determine "OK", which is appropriate as a reception position. In the example of FIG. 4, the "opening ratio result" and the "PDOP result" are indicated by character strings of "OK" and "NG", but may be numerical values or the like indicating each.

The "antenna ID" is an identifier that uniquely indicates the GNSS antenna to be installed at the point where the target sky image is taken. When a plurality of sky images are analyzed in order to determine the installation position of one GNSS antenna, data records having different "sky image IDs" and the same "antenna ID" are generated. Alternatively, the "antenna ID" can be managed by assigning serial numbers such as "12345-1", "12345-2", "12345-3", and so on.

In addition, the analysis result storage unit 123 can also store analysis results such as a PDOP value for 24 hours and a maximum value, a minimum value, and an average value of the PDOP. In addition, the storage unit stores the analysis application. The sky moving image storage unit 121, the sky image storage unit 122, and the analysis result storage unit 123 are not limited to the above, and various information may be stored depending on the purpose.

(Control unit 130)
The control unit 130 is a processing unit that controls the entire terminal device 100, and is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or the like (so-called processor). The control unit 130 expands and executes various programs (for example, the image analysis program according to the present application) stored in the storage unit 120 in a RAM serving as a work area. Further, the control unit 130 is realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), for example.

As shown in FIG. 3, the control unit 130 includes an acquisition unit 131, a display unit 132, and an input unit 133, and realizes or executes an image analysis function or operation described below. The internal configuration of the control unit 130 is not limited to the configuration shown in FIG. 3, and may be any other configuration as long as it executes the image analysis process described later. Further, the connection relationship of each processing unit included in the control unit 130 is not limited to the connection relationship shown in FIG. 3, and may be another connection relationship.

(Acquisition unit 131)
The acquisition unit 131 acquires various types of information. For example, the acquisition unit 131 acquires a sky moving image photographed by the photographing camera 10. Specifically, the acquisition unit 131 acquires the sky moving image from the photographing camera 10 connected by the USB cable in response to the user's operation on the analysis application. In addition, the acquisition unit 131 acquires a sky image from the acquired sky moving image. Specifically, for example, the central frame (one frame of the moving image) of the playback time of the sky moving image is acquired as a sky image. This is because the user or his / her shadow may be reflected in the captured video. Therefore, for example, a video of several tens of seconds is shot, and a frame in a time zone when the user is away from the shooting camera 10 is acquired as a sky image. Because. It should be noted that, for example, the sky image can be acquired by playing the sky moving image on the analysis application and letting the user select an arbitrary frame.

(Display unit 132)
The display unit 132 displays various information. For example, the display unit 132 displays the processed image in which the sky portion is extracted by the image analysis device 200 and the analysis result of the sky image. Specifically, the display unit 132 displays the processed image and the analysis result received by the communication unit 110 from the image analysis device 200 via the analysis application displayed on the output device.

(Input unit 133)
The input unit 133 accepts input of various information. For example, the input unit 133 accepts a user's selection for a plurality of processed images as user input. Specifically, the input unit 133 accepts the processed image selected by the input device as the user input from the plurality of processed images displayed via the analysis application.

[3. Configuration of image analysis device 200]
Next, the functional configuration of the image analysis apparatus 200 according to the embodiment will be described with reference to FIG. FIG. 5 is a diagram showing a functional configuration example of the image analysis device 200 according to the embodiment. As shown in FIG. 5, the image analysis device 200 includes a communication unit 210, a storage unit 220, and a control unit 230.

(Communication unit 210)
Like the communication unit 110 of the terminal device 100, the communication unit 210 transmits / receives information to / from the image analysis device 200 via the network N.

(Storage 220)
The storage unit 220 is realized by a RAM or the like, like the storage unit 120 of the terminal device 100. As shown in FIG. 5, the storage unit 220 includes an orbital data storage unit 221, a sky image storage unit 222, and an analysis result storage unit 223. Hereinafter, each storage unit included in the storage unit 220 will be described in order.

(Orbital data storage unit 221)
The orbit data storage unit 221 stores information on the orbit of each positioning satellite in the GNSS. GNSS is an all-satellite positioning system consisting of global satellite systems such as GPS (Global Positioning System) in the United States, Galileo in the European Union (EU), and GLONASS in Russia, and regional satellite systems such as Michibiki in Japan. including. Therefore, the orbit data storage unit 221 stores the identifier of each positioning satellite and each orbit data in association with each other. For example, depending on the area where the GNSS antenna is installed, the positioning satellite of the regional satellite system cannot be captured at all without moving over the area. Therefore, the orbit data storage unit 221 can store only the data of the positioning satellite captured by the GNSS antenna, or can set an valid flag or the like and use only the data indicating that it is valid as the orbit data.

(Sky image storage unit 222)
The sky image storage unit 222 stores the sky image transmitted from the terminal device 100. The sky image is basically the same as the sky image stored in the sky image storage unit 122 of the terminal device 100. FIG. 6 is a diagram showing an example of a sky image according to the embodiment. As shown in FIG. 6, the sky image 300 is digital data of a sky photograph taken by a 360-degree camera, and includes a circular subject portion 301 and other background portions 302. In the example of FIG. 6, it can be seen that the steel tower is shown in the upper right of the subject portion 301, and the surrounding buildings, trees, and the ground are shown in the vicinity of the inner edge of the circumference. Such a portion other than the sky becomes a shield that hinders the observation and reception of the GNSS signal, and deteriorates the positioning accuracy.

(Analysis result storage unit 223)
The analysis result storage unit 223 stores information related to the analysis result of the sky image, like the analysis result storage unit 123 of the terminal device 100.

(Control unit 230)
The control unit 230 is a processing unit that controls the entire image analysis device 200, like the control unit 130 of the terminal device 100. As shown in FIG. 5, the control unit 230 includes an acquisition unit 231, an image processing unit 232, and a determination unit 233. The internal configuration of the control unit 230 is not limited to the configuration and connection relationship shown in FIG.

(Acquisition unit 231)
The acquisition unit 231 acquires various types of information. For example, the acquisition unit 231 acquires a sky image from the terminal device 100. Specifically, the acquisition unit 231 acquires the sky image received by the communication unit 210 from the terminal device 100.

(Image processing unit 232)
The image processing unit 232 performs image processing on the sky image. For example, the image processing unit 232 performs filtering processing such as edge processing on the sky image acquired from the terminal device 100, and the boundary between the empty part and a part other than the sky (shield) such as a building or a tree. The empty part is extracted by detecting. FIG. 7 is a diagram showing an example of image processing for extracting an empty portion according to the embodiment. As shown in FIG. 7, the sky portion 311 of the subject portion 301 can be extracted by performing the filtering process on the sky image 300. Further, the image processing unit 232 masks the non-empty portion 312 by masking processing to generate the processed image 310. The masked area is excluded from the analysis target of the sky image.

In the example of FIG. 7, an empty portion also exists in the gap between the steel towers shown from above to the upper right of the subject portion 301. However, since it is practically difficult to capture a positioning satellite that is constantly moving from this gap, for example, a filtering process such as a morphology closing process is executed, and such a part is also a part 312 other than the sky. I'm masking it as if it were.

Further, in order to improve the accuracy of boundary detection between the empty part and the non-empty part, a filtering process such as a binarization process can be executed. FIG. 8 is a diagram showing an example of a histogram for the binarization process according to the embodiment. For example, when a sky image is grayscale-converted and expressed in 256 gradations, the sky portion tends to show a high degree of gradation. Therefore, as shown in FIG. 8, a threshold value (broken line portion, for example, gradation degree 150) can be set for the gradation degree, and an empty portion above the threshold value and a non-empty portion below the threshold value can be determined. The threshold value can be set to an arbitrary value in advance, or can be automatically determined by executing image processing using a predetermined function on the sky image.

Further, the extraction accuracy of the sky portion changes depending on the weather, the amount and type of the shield, the shooting parameters of the shooting camera 10 (for example, exposure and focus), and the like. Therefore, the image processing unit 232 can also perform filtering processing such as color tone correction, gamma correction, and unsharp masking processing based on the weather and the like. Further, the image processing unit 232 can determine a region to be excluded from the analysis target of the sky image.

FIG. 9 is a diagram showing an example of a region excluded from the analysis target according to the embodiment. In the example of FIG. 9, in addition to the non-sky portion 312 excluded from the analysis target of the sky image by the filtering process, the processed image 320 further excludes the satellite out-orbit region 313 and the horizontal predetermined region 314 from the analysis target. be.

Regarding the satellite orbital region 313, for example, since the positioning satellite does not pass through the north side in the case of the northern hemisphere and the south side in the case of the southern hemisphere, a predetermined region indicating the north side or the south side from the imaging point can be excluded from the analysis target. Specifically, a predetermined region of the sky image can be excluded from the analysis target by predetermining it as a satellite out-orbit region 313 (which can be defined by the coordinates of the image) and masking that portion by masking processing. .. As a result, more accurate analysis can be performed. In the vicinity of the equator at latitude 0 degrees, positioning satellites pass through the entire area. Whether or not to determine the satellite orbital region 313, and if so, which part and which range to determine, can be determined from the latitude of the imaging point.

Further, the horizontal predetermined region 314 will be described. FIG. 10 is a diagram showing an example of a horizontal region excluded from the analysis target according to the embodiment. As shown in FIG. 10, the area at a predetermined angle (for example, 5 °) from the horizontal direction with respect to the photographing point (imaging camera 10) reflects the ground and the like, and the sky cannot be photographed. Therefore, the area is excluded from the analysis target. be able to. This can also be excluded from the analysis target by predetermining and masking a predetermined region of the sky image as a predetermined region 314 in the horizontal direction. As a result, more accurate analysis can be performed.

FIG. 11 is a diagram showing an example of the original image and each processed image according to the embodiment. The image processing unit 232 generates a plurality of processed images 310, 320, 330 having different extraction patterns, and as shown in FIG. 11, for example, displays an analysis application so that it can be compared with the sky image 300 (original image). Present to the user via. As a result, the user can select one processed image to be analyzed from the plurality of processed images. In the example of FIG. 11, there are three types of processed images, but the number of processed images generated by the image processing unit 232 and presented to the user may be larger or smaller.

In addition, the image processing unit 232 calculates the sky aperture ratio and the PDOP value for the processed image. Taking FIG. 9 as an example, the sky aperture ratio is the ratio of the pixels of the empty portion 311 among the pixels obtained by removing the background portion 302 from the processed image 320.

Moreover, the PDOP value will be described. FIG. 12 is a diagram showing an example of a composite image of the sky image and the satellite orbit according to the embodiment. The left side of FIG. 12 is a composite image 340 in which the orbits of each positioning satellite are combined with the sky image based on the orbit data. Further, the right side of FIG. 12 is a composite image 350 excluding the satellite orbit of the portion because the satellite overlapping the portion 312 other than the sky cannot be captured. Based on such a composite image 350, the image processing unit 232 can index the arrangement state of each positioning satellite in the empty portion and calculate the PDOP value.

(Judgment unit 233)
The determination unit 233 determines the calculated sky opening ratio and PDOP value based on the respective threshold values. Further, the determination unit 233 generates an analysis result as shown in FIG. 4 based on the determination result of the sky opening ratio and the PDOP value. For example, when the sky opening ratio is equal to or higher than a predetermined threshold value, the determination unit 233 determines that the result of the sky opening ratio is “OK” and sets “OK” in the “opening ratio result” shown in FIG. Further, the determination unit 233 determines, for example, that the PDOP result is "OK" when the PDOP value below the predetermined threshold value is equal to or more than the predetermined ratio within 24 hours, and the "PDOP result" shown in FIG. Set to "OK".

FIG. 13 is a diagram showing an example of an analysis result screen of the analysis application according to the embodiment. As shown in FIG. 13, the analysis result generated by the determination unit 233 can be displayed via the analysis application 400. The display content of the analysis application 400 in FIG. 13 is an example, and is not limited to this. It is possible to increase or decrease the display of the original image of the sky image, the processed image, and the analysis result, and change the size and arrangement of those displays. Further, the shape and size of the display area, the color and size of the font, the transmittance, and the like are also examples.

[4. Processing procedure]
Next, the procedure of the image analysis processing for the sky image according to the embodiment will be described with reference to FIG. FIG. 14 is a flowchart showing the flow of image analysis processing for the sky image according to the embodiment. The image analysis process shown in FIG. 14 starts from the point where the user connects the terminal device 100 and the photographing camera 10 and starts the analysis application installed in the terminal device 100.

As shown in FIG. 14, the acquisition unit 131 of the terminal device 100 acquires, for example, a sky moving image shot by the shooting camera 10 from the shooting camera 10 in response to a user operation via an analysis application, and obtains the sky moving image from the shooting camera 10. It is stored in the storage unit 121 (step S101). The user operation referred to here is, for example, pressing the sky moving image acquisition button on the analysis application. Alternatively, the sky moving image may be acquired in response to the connection of the photographing camera 10 to the terminal device 100. It should be noted that the acquisition of the sky moving image does not have to be executed immediately after shooting by the shooting camera 10, and may be executed at a place other than the shooting point (for example, the user's company).

Next, the acquisition unit 131 acquires a sky image from the acquired sky moving image in response to a user operation via the analysis application and stores it in the sky image storage unit 122 (step S102). Is, for example, pressing the sky image acquisition button on the analysis application. Alternatively, the sky image may be acquired in response to the completion of the acquisition of the sky moving image. The sky image to be acquired is, for example, the center frame of the playback time of the sky movie, but may be a frame other than that, or the sky movie is displayed via the display unit 132, and an arbitrary frame is given to the user. It may be selected via the input unit 133.

Next, the acquisition unit 131 transmits the acquired sky image to the image analysis device 200 via the communication unit 110 in response to a user operation via the analysis application, for example (step S103). The user operation referred to here is, for example, pressing the send button on the analysis application.

Next, the acquisition unit 231 of the image analysis device 200 determines whether or not the sky image has been received from the terminal device 100 (step S104). When it is determined that the sky image has not been received (step S104: No), the acquisition unit 231 waits for the reception of the sky image. When it is determined that the sky image has been received (step S104: Yes), the acquisition unit 231 receives the sky image via the communication unit 210 and stores it in the sky image storage unit 222.

Next, the image processing unit 232 executes a filtering process on the received sky image in order to extract the empty portion (step S105). Subsequently, the image processing unit 232 executes masking processing on the non-empty portion in order to mask the extracted non-empty portion (step S106). As a result, the processed image is generated. Further, the image processing unit 232 can execute the filtering process (step S105) and the masking process (step S106) by changing the filter and the filter parameters to generate a plurality of processed images. This allows the user to select the processed image with the most correctly extracted empty areas. Each processed image is also stored in the sky image storage unit 122.

Next, the image processing unit 232 transmits the generated one or more processed images to the terminal device 100 via the communication unit 210 (step S107).

Next, the acquisition unit 131 of the terminal device 100 determines whether or not the processed image has been received from the image analysis device 200 (step S108). When it is determined that the processed image has not been received (step S108: No), the acquisition unit 131 waits for the reception of the processed image. When it is determined that the processed image has been received (step S108: Yes), the acquisition unit 131 receives the processed image via the communication unit 110.

Next, the display unit 132 displays the received one or more processed images via the analysis application (step S109). Subsequently, the input unit 133 receives the user input and transmits the user input to the image analysis device 200 via the communication unit 110 (step S110). The user input here is, for example, an identifier of the processed image that executes the image analysis process. If there are multiple processed images, the user selects one processed image.

Next, the acquisition unit 231 of the image analysis device 200 determines whether or not the user input has been received from the terminal device 100 (step S111). If it is determined that the user input has not been received (step S111: No), the acquisition unit 231 waits for the reception of the user input. When it is determined that the sky image has been received (step S111: Yes), the acquisition unit 231 receives the user input via the communication unit 210.

Next, the image processing unit 232 calculates the sky opening ratio with respect to the processed image (step S112). Further, the image processing unit 232 calculates the PDOP value for the processed image (step S113). The execution order of steps S112 and S113 may be reversed, or parallel processing may be performed.

Next, the determination unit 233 determines the calculated sky opening ratio and PDOP value based on the respective threshold values (step S114). Subsequently, the determination unit 233 generates an analysis result based on the determination result of the sky opening ratio and the PDOP value, and stores it in the analysis result storage unit 223 (step S115). Further, the determination unit 233 transmits the generated analysis result to the terminal device 100 via the communication unit 210 (step S116).

Next, the acquisition unit 131 of the terminal device 100 determines whether or not the analysis result has been received from the image analysis device 200 (step S117). When it is determined that the analysis result has not been received (step S117: No), the acquisition unit 131 waits for the analysis result to be received. When it is determined that the analysis result has been received (step S117: Yes), the acquisition unit 131 receives the analysis result via the communication unit 110 and stores it in the analysis result storage unit 123.

Next, the display unit 132 displays the received analysis result via the analysis application (step S118). After step S118, the image analysis process shown in FIG. 14 ends.

[5. effect〕
As described above, the image analysis system according to the embodiment includes a photographing camera 10, a terminal device 100, and an image analysis device 200. The shooting camera 10 acquires a sky moving image at the first point. The terminal device 100 acquires a sky moving image from the shooting camera 10, and acquires a frame as a sky image after a lapse of a predetermined time from the start of the sky moving image. The image analysis device 200 acquires a sky image from the terminal device 100, extracts a part of the sky included in the sky image by executing a filtering process on the sky image, and receives a signal from the GNSS antenna. Calculate the index value to evaluate the situation.

As described above, the image analysis system according to the embodiment executes a filtering process to extract an empty portion included in the sky image, and an index value for evaluating the reception status of the GNSS antenna with respect to the empty portion. By calculating, the reception status of the GNSS antenna can be evaluated in a shorter time.

Further, the image analysis device 200 according to the embodiment further calculates the ratio of the sky portion to the sky image.

As described above, the image analysis device 200 according to the embodiment can evaluate the reception status of the GNSS antenna in a shorter time by calculating the ratio of the sky portion to the sky image (sky aperture ratio).

Further, the filtering process executed by the image analysis apparatus 200 according to the embodiment is at least an edge process, and the edge process detects the boundary between the empty portion and the shield and extracts the empty portion.

As described above, the image analysis apparatus 200 according to the embodiment can appropriately extract the sky portion from the sky image by executing the edge processing on the sky image.

Further, in the image analysis apparatus 200 according to the embodiment, the index value for evaluating the reception status of the GNSS antenna that receives the GNSS signal is the PDOP value.

As described above, the image analysis apparatus 200 according to the embodiment can evaluate the reception status of the GNSS antenna in a shorter time by calculating the PDOP value.

Further, the calculation of the PDOP value by the image analysis device 200 according to the embodiment is based on the orbital data of the GNSS passing over the first point at a fixed time and the sky image, and a plurality of PDOPs at predetermined time intervals. The value is calculated, and the ratio of the PDOP value in which each of the plurality of PDOP values is less than a predetermined second threshold value is calculated.

As described above, the image analysis device 200 according to the embodiment calculates a plurality of PDOP values at predetermined time intervals based on the orbital data and the sky image, and each of the plurality of PDOP values is a predetermined second. By calculating the ratio of the PDOP value that is less than the threshold value of, the reception status of the GNSS antenna can be evaluated in a shorter time.

Further, the image analysis device 200 according to the embodiment executes a filtering process to fill the gaps of the shield included in the sky image and then extract the empty portion.

As described above, the image analysis apparatus 200 according to the embodiment can extract the empty portion after filling the gap of the shield, which is substantially difficult to capture the constantly moving positioning satellite. ..

Further, the image analysis device 200 according to the embodiment further determines whether or not the ratio of the sky portion to the sky image is equal to or higher than a predetermined third threshold value, and generates an analysis result based on the determination result. ..

In this way, the image analysis device 200 according to the embodiment determines whether or not the ratio of the sky portion to the sky image is equal to or higher than a predetermined third threshold value, and generates an analysis result based on the determination result. By doing so, the analysis result for the ratio of the sky (sky opening ratio) can be displayed to the user.

Further, the image analysis device 200 according to the embodiment further determines whether or not the ratio of the PDOP value is equal to or higher than a predetermined fourth threshold value, and generates an analysis result based on the determination result.

In this way, the image analysis device 200 according to the embodiment determines whether or not the ratio of the PDOP values is equal to or higher than a predetermined fourth threshold value, and generates an analysis result based on the determination result. The analysis result for the PDOP value can be displayed to the user.

Further, the calculation of the ratio of the PDOP value by the image analysis device 200 according to the embodiment is executed after excluding the region outside the satellite orbit determined from the latitude of the first point from the sky image.

As described above, the image analysis device 200 according to the embodiment can perform more accurate analysis by executing the calculation of the ratio of the PDOP value after excluding the region outside the satellite orbit from the sky image.

Further, the image analysis device 200 according to the embodiment calculates the ratio of the PDOP value after excluding the region at a predetermined angle from the horizontal direction with respect to the first point from the sky image.

As described above, the image analysis device 200 according to the embodiment is more accurate by calculating the ratio of the PDOP value after excluding the region of a predetermined angle from the horizontal direction with respect to the first point from the sky image. Can be analyzed.

Further, the calculation of the ratio of the PDOP value by the image analysis device 200 according to the embodiment is executed for one image selected by the user from a plurality of sky images in which a plurality of different filtering processes are executed.

As described above, the image analysis device 200 according to the embodiment calculates the ratio of the PDOP value to one image selected by the user from the plurality of sky images that have been subjected to a plurality of different filtering processes. Therefore, more accurate analysis can be performed.

Further, the image analysis device 200 according to the embodiment further determines the filtering process to be executed on the sky image based on the weather at the time when the sky moving image is taken, and the image analysis device 200 extracts the sky part. , It is performed by executing the determined filtering process.

As described above, the image analysis device 200 according to the embodiment determines the filtering process to be executed on the sky image based on the weather at the time when the sky moving image is taken, and executes the determined filtering process to execute the determined filtering process to determine the empty portion. By performing the extraction of, the reception status of the GNSS antenna can be evaluated in a shorter time.

[6. Hardware configuration]
The terminal device 100 and the image analysis device 200 described above are realized by, for example, a computer 1000 having a configuration as shown in FIG. FIG. 15 is a hardware configuration diagram showing an example of a computer that realizes the functions of each device. The computer 1000 has a CPU 1100, a RAM 1200, a ROM 1300, an HDD 1400, a communication interface (I / F) 1500, an input / output interface (I / F) 1600, and a media interface (I / F) 1700.

The CPU 1100 operates based on a program stored in the ROM 1300 or the HDD 1400, and controls each part. The ROM 1300 stores a boot program executed by the CPU 1100 when the computer 1000 is started, a program that depends on the hardware of the computer 1000, and the like.

The HDD 1400 stores a program executed by the CPU 1100, data used by the program, and the like. The communication interface 1500 receives data from another device via the network N and sends it to the CPU 1100, and transmits the data collected by the CPU 1100 to the other device via the network N.

The CPU 1100 controls an output device such as a display or a printer, and an input device such as a keyboard or a mouse via the input / output interface 1600. The CPU 1100 acquires data from the input device via the input / output interface 1600. Further, the CPU 1100 outputs the collected data to the output device via the input / output interface 1600.

The media interface 1700 reads a program or data stored in the recording medium 1800 and provides the program or data to the CPU 1100 via the RAM 1200. The CPU 1100 loads the program from the recording medium 1800 onto the RAM 1200 via the media interface 1700, and executes the loaded program. The recording medium 1800 is an optical recording medium such as a DVD (Digital Versaille Disc) or PD (Phase change rewritable disc), a magneto-optical recording medium such as an MO (Magnet-Optical disc), a tape medium, a magnetic recording medium, or a semiconductor memory. And so on.

For example, when the computer 1000 functions as the terminal device 100 or the image analysis device 200, the CPU 1100 of the computer 1000 realizes the functions of the control units 130 and 230 by executing the program loaded on the RAM 1200. The CPU 1100 of the computer 1000 reads and executes these programs from the recording medium 1800, but as another example, these programs may be acquired from another device via the network N.

The embodiments of the present application have been described in detail with reference to the drawings, but these are examples, and various modifications and improvements are made based on the knowledge of those skilled in the art, including the embodiments described in the disclosure line of the invention. It is possible to carry out the present invention in other forms described above.

[7. others〕
Further, among the processes described in the above-described embodiment, all or a part of the processes described as being automatically performed can be manually performed, or the processes described as being manually performed can be performed. All or part of it can be done automatically by a known method. In addition, the processing procedure, specific name, and information including various data and parameters shown in the above document and drawings can be arbitrarily changed unless otherwise specified. For example, the various information shown in each figure is not limited to the illustrated information.

Further, each component of each of the illustrated devices is a functional concept, and does not necessarily have to be physically configured as shown in the figure. That is, the specific form of distribution / integration of each device is not limited to the one shown in the figure, and all or part of the device is functionally or physically dispersed / physically distributed in any unit according to various loads and usage conditions. Can be integrated and configured.

Further, the above-described embodiments can be appropriately combined as long as the processing contents do not contradict each other.

Further, the above-mentioned "part (module, module, unit)" can be read as "means", "circuit" and the like. For example, the acquisition unit can be read as an acquisition means or an acquisition circuit.

1 Information processing system 2 Server 3 Reference station 4 GNSS positioning satellite 5 Mobile station 6 Automobile 10 Shooting camera 50 Communication cable 100 Terminal device 110 Communication unit 120 Storage unit 121 Sky video storage unit 122 Sky image storage unit 123 Analysis result storage unit 130 Control unit 131 Acquisition unit 132 Display unit 133 Input unit 200 Image analysis device 210 Communication unit 220 Storage unit 221 Orbital data storage unit 222 Sky image storage unit 223 Analysis result storage unit 230 Control unit 231 Acquisition unit 232 Image processing unit 233 Judgment unit N network

Claims (20)

A shooting camera that acquires a sky movie at the first point,
The sky moving image is acquired from the shooting camera, and the sky moving image is acquired.
A terminal device that acquires a frame in a time zone when the user is away from the shooting camera as a sky image after a lapse of a predetermined time from the start of the sky moving image.
The sky image is acquired from the terminal device, and the sky portion included in the sky image is extracted by executing a filtering process on the sky image.
An image analysis system characterized by being equipped with an image analysis device that calculates an index value for evaluating the reception status of a GNSS antenna that receives signals from a global navigation satellite system (GNSS). The image analysis system according to claim 1, wherein the image analysis device further calculates the ratio of the sky portion to the sky image. The filtering process executed by the image analysis apparatus is at least an edge process, and the edge process detects a boundary between the empty portion and a shield and extracts the empty portion. The image analysis system according to 1. The image analysis system according to claim 1, wherein the index value is a PDOP value for the empty portion. The calculation of the PDOP value by the image analyzer is
A plurality of PDOP values for each predetermined time are calculated based on the orbital data of the GNSS passing over the first point at a fixed time and the sky image.
The image analysis system according to claim 4, wherein each of the plurality of PDOP values includes calculating a ratio of PDOP values that is less than a predetermined second threshold value. The image analysis system according to claim 1, wherein the image analysis apparatus executes the filtering process to fill a gap of a shield included in the sky image and then extracts the empty portion. .. The image analysis device is further characterized in that it determines whether or not the ratio of the empty portion to the sky image is equal to or higher than a predetermined third threshold value, and generates an analysis result based on the determination result. The image analysis system according to claim 2. The fourth aspect of the present invention is characterized in that the image analysis apparatus further determines whether or not the ratio of the PDOP values is equal to or higher than a predetermined fourth threshold value, and generates an analysis result based on the determination result. The image analysis system described. The claim is characterized in that the calculation of the ratio of the PDOP value by the image analysis device is executed after excluding the region outside the satellite orbit determined from the latitude of the first point from the sky image. The image analysis system according to 4. According to claim 4, the calculation of the ratio of the PDOP value by the image analysis device is performed after excluding a region at a predetermined angle from the horizontal direction with respect to the first point from the sky image. The described image analysis system. The image analysis apparatus is characterized in that the calculation of the ratio of the PDOP value is performed on one image selected by the user from the plurality of sky images that have each performed the plurality of different filtering processes. The image analysis system according to claim 4. The image analyzer further
Based on the weather at the time the sky moving image was taken, the filtering process to be executed on the sky image is determined.
The image analysis system according to claim 1, wherein the extraction of the empty portion by the image analysis device is performed by executing the determined filtering process. The image analyzer
Acquire the sky movie taken by the shooting camera at the first point,
A frame in a time zone when the user is away from the shooting camera after a lapse of a predetermined time from the start of the sky moving image is acquired as a sky image.
By executing the filtering process on the sky image, the sky part included in the sky image is extracted.
An image analysis method characterized by executing a process of calculating an index value for evaluating the reception status of a GNSS antenna that receives a signal from a global navigation satellite system (GNSS). For image analysis equipment
Acquire the sky movie taken by the shooting camera at the first point,
A frame in a time zone when the user is away from the shooting camera after a lapse of a predetermined time from the start of the sky moving image is acquired as a sky image.
By executing the filtering process on the sky image, the sky part included in the sky image is extracted.
An image analysis program characterized by executing a process of calculating an index value for evaluating the reception status of a GNSS antenna that receives a signal from a global navigation satellite system (GNSS). A shooting camera that shoots a sky movie for a certain period of time at the first point,
The sky moving image taken for a certain period of time is acquired from the shooting camera.
A terminal device that acquires a frame as a sky image after a predetermined time shorter than the fixed time has elapsed from the start of the sky moving image for a fixed time.
The sky image is acquired from the terminal device, and the sky portion included in the sky image is extracted by executing a filtering process on the sky image.
An image analyzer that calculates an index value that evaluates the reception status of a GNSS antenna that receives signals from the Global Navigation Satellite System (GNSS).
An image analysis system characterized by being equipped with. The image analyzer
Acquire the sky video taken for a certain period of time at the first point,
A frame after a predetermined time shorter than the fixed time has elapsed from the start of the sky moving image for the fixed time is acquired as a sky image.
By executing the filtering process on the sky image, the sky part included in the sky image is extracted.
Calculate the index value to evaluate the reception status of the GNSS antenna that receives the signal from the Global Navigation Satellite System (GNSS).
An image analysis method characterized by performing processing. For image analysis equipment
Acquire the sky video taken for a certain period of time at the first point,
A frame after a predetermined time shorter than the fixed time has elapsed from the start of the sky moving image for the fixed time is acquired as a sky image.
By executing the filtering process on the sky image, the sky part included in the sky image is extracted.
Calculate the index value to evaluate the reception status of the GNSS antenna that receives the signal from the Global Navigation Satellite System (GNSS).
An image analysis program characterized by executing processing. A shooting camera that acquires a sky movie at the first point,
The sky moving image is acquired from the shooting camera, and the sky moving image is acquired.
A terminal device that acquires the central frame of the sky movie as a sky image, and
The sky image is acquired from the terminal device, and the sky portion included in the sky image is extracted by executing a filtering process on the sky image.
An image analyzer that calculates an index value that evaluates the reception status of a GNSS antenna that receives signals from the Global Navigation Satellite System (GNSS).
An image analysis system characterized by being equipped with. The image analyzer
Acquire the sky video taken at the first point,
The central frame of the sky movie is acquired as a sky image, and
By executing the filtering process on the sky image, the sky part included in the sky image is extracted.
Calculate the index value to evaluate the reception status of the GNSS antenna that receives the signal from the Global Navigation Satellite System (GNSS).
An image analysis method characterized by performing processing. For image analysis equipment
Acquire the sky video taken at the first point,
The central frame of the sky movie is acquired as a sky image, and
By executing the filtering process on the sky image, the sky part included in the sky image is extracted.
Calculate the index value to evaluate the reception status of the GNSS antenna that receives the signal from the Global Navigation Satellite System (GNSS).
An image analysis program characterized by executing processing.

Images