Wavebreaking evaluation graph generation device, wavebreaking evaluation graph generation system, wavebreaking evaluation graph generation method, and program

Abstract

This invention provides a wave-breaking evaluation graph generation device, a wave-breaking evaluation graph generation system, a wave-breaking evaluation graph generation method, and a program that can provide data combining wave-breaking information and surfer information about surfers riding those waves. [Solution] The wave breaking evaluation graph generation device 13 includes an information acquisition unit 51 that acquires information on the time of wave breaking, the height of the wave breaking, and surfer information regarding surfers riding the wave, and a presentation information generation unit 52 that generates presentation information in graph format showing the height of the wave breaking and surfer information for each time of wave breaking.

Description

[Technical Field] 【0001】 The present invention relates to a wave breaking evaluation graph generation device, a wave breaking evaluation graph generation system, a wave breaking evaluation graph generation method, and a program. [Background technology] 【0002】 Many marine activities utilize breaking waves, with surfing being a prime example. Surfing is greatly influenced by the conditions of the breaking waves. Therefore, there is a need for data on breaking wave conditions for surfers. For example, data combining information on the breaking waves with information on the surfers riding those waves would be useful in identifying breaking waves suitable for surfing. 【0003】 Patent Document 1 discloses a technique for generating wave breaking data, including wave breaking height, by analyzing video data of a landscape that includes a sea surface area where wave breaking can occur. [Prior art documents] [Patent Documents] 【0004】 [Patent Document 1] Japanese Patent Publication No. 2005-009903 [Overview of the Initiative] [Problems that the invention aims to solve] 【0005】 However, Patent Document 1 does not disclose a technique for combining information about breaking waves with information about surfers riding those waves. 【0006】 This invention has been made in view of the above problems, and its purpose is to provide a wave breaking evaluation graph generation device, a wave breaking evaluation graph generation system, a wave breaking evaluation graph generation method, and a program that can provide data that combines wave breaking information and surfer information about surfers riding those waves. [Means for solving the problem] 【0007】 The process includes an information acquisition step of acquiring information on the time of wave occurrence, wave height, and surfer information regarding surfers riding the waves, and a presentation information generation step of generating presentation information in graph format that shows the wave height and surfer information for each time of wave occurrence. [Effects of the Invention] 【0008】 According to the present invention, it is possible to provide data that combines information about breaking waves and information about surfers riding those waves. [Brief explanation of the drawing] 【0009】 [Figure 1] Figure 1 shows an example of the configuration of a wave breaking evaluation graph generation system. [Figure 2] Figure 2 is a block diagram showing the functional configuration of the video analysis device 12. [Figure 3] Figure 3 is a diagram illustrating wave breaking. [Figure 4] Figure 4 shows the wave breaking extracted using a frame. [Figure 5] Figure 5 illustrates the extraction of surfers riding breaking waves. [Figure 6] Figure 6 is a table showing an example of information regarding wave height and the presence or absence of surfers riding the waves, linked to the time of wave breaking. [Figure 7] Figure 7 is a flowchart showing the flow of the image analysis process. [Figure 8] Figure 8 is a block diagram showing the functional configuration of the wave breaking evaluation graph generation device 13. [Figure 9] Figure 9 is an example of the graph generated by the presentation information generation unit 52. [Figure 10] Figure 10 is a graph in which the bars indicating the breaking waves with a rider are colored black for the graph of Figure 9. [Figure 11] Figure 11 is a flowchart showing the flow of the breaking wave graph generation process. [Figure 12] Figure 12 is a table showing an example of the height of the breaking wave, the information on the presence or absence of a rider for the breaking wave, and the riding time, associated with the occurrence time of the breaking wave. [Figure 13] Figure 13 is an example of the graph generated by the presentation information generation unit 52. [Figure 14] Figure 14 is an example of the display screen 61 of the user terminal 14. [Figure 15] Figure 15 is a diagram for explaining an example of the designation of the exclusion region by the breaking wave analysis unit 32. [Figure 16] Figure 16 is a diagram showing an example of the positional relationship between the camera 11 and the breaking wave. [Figure 17] Figure 17 is a diagram for explaining the difference between the apparent wave height Happ and the true wave height Htrue. [Figure 18] Figure 18 is a diagram for explaining an example of the evaluation of the video quality by the breaking wave analysis unit 32. [Figure 19] Figure 19 is a diagram for explaining an example of the evaluation of the video quality by the breaking wave analysis unit 32. [Figure 20] Figure 20 is a diagram for explaining an example of the evaluation of the video quality by the breaking wave analysis unit 32. 【Mode for Carrying Out the Invention】 【0010】 [One Embodiment] Figure 1 is a diagram showing a configuration example of a breaking wave evaluation graph generation system according to the present embodiment. The breaking wave evaluation graph generation system includes a camera 11, a video analysis device 12, a breaking wave evaluation graph generation device 13, and a user terminal 14. 【0011】 Camera 11 is installed, for example, on a beach and captures a waterscape that may include surfers and where waves may break. Camera 11 supplies the acquired images to the image analysis device 12. Here, "waterscape" includes the sea, rivers, lakes, swimming pools, etc. 【0012】 A surfer is someone who surfs. Surfers wait for waves while straddling their surfboard, or they may lie on the surfboard and propel themselves through the water with their hands (paddling) as the wave moves, before standing up on the board at the right moment. Surfers then use the power of the wave to propel themselves forward and ride the wave. A surfer who is riding a wave will be referred to as a riding surfer below. 【0013】 Wave breaking is a phenomenon that occurs when waves enter shallow waters from offshore, their wave height changes, and they break forward when the water depth approaches the wave height, resulting in turbulent motion. 【0014】 The video analysis device 12 can be a cloud server, a PC (personal computer), a smartphone, a tablet, etc. Based on the video captured by the camera 11, the video analysis device 12 analyzes the waves and surfers within the shooting range and supplies the analysis results to the wave evaluation graph generation device 13 and the user terminal 14. The video analysis device 12 may be a standalone device or may be integrated into the camera 11, etc. 【0015】 The video captured by camera 11 may be temporarily stored on an external server or PC, and the video analysis device 12 may analyze the stored video. For example, the video analysis device 12 may analyze video distributed via live streaming that is stored on an external server or PC. 【0016】 The wave-breaking evaluation graph generation device 13 can be a cloud server, a PC (personal computer), a smartphone, a tablet, etc. The wave-breaking evaluation graph generation device 13 generates a graph based on the analysis results of the waves and surfers analyzed by the video analysis device 12, and supplies the generated graph to the user terminal 14. The wave-breaking evaluation graph generation device 13 may be a standalone device or may be integrated into the video analysis device 12, user terminal 14, etc. 【0017】 The user terminal 14 is, for example, a smartphone, and can display graphs received via the network from the wave breaking evaluation graph generation device 13. 【0018】 (Functional configuration of the video analysis device 12) As shown in Figure 2, the video analysis device 12 is configured to include a communication unit 21, a storage unit 22, and a control unit 23. 【0019】 The communication unit 21 communicates with the camera 11, the wave breaking evaluation graph generation device 13, and the user terminal 14. The communication unit 21 may transmit various types of information using short-range wireless communication such as Bluetooth® or Wi-Fi®. Furthermore, it may exchange information with external servers and various services via a network (not shown) using wide-area wireless communication. 【0020】 The storage unit 22 includes, for example, ROM (Read Only Memory), RAM (Random Access Memory), and non-volatile memory. The storage unit 22 stores control application programs executed by the control unit 23, various data necessary for their execution, and information generated by processing. 【0021】 The control unit 23 consists of a CPU (Central Processing Unit), memory units (ROM (Read Only Memory), RAM (Random Access Memory), non-volatile memory, etc.), hardware, and other elements. The control unit 23 controls the entire video analysis device 12 by executing a control application program (not shown) stored in the memory unit 22, and also functions as the video acquisition unit 31, wave breaking analysis unit 32, surfer analysis unit 33, and output processing unit 34. 【0022】 ((Video acquisition unit 31)) The video acquisition unit 31 acquires video data captured by the camera 11 and stores it in the storage unit 22. The video captured by the camera 11 is captured as a series of images over a predetermined period of time. Therefore, the video acquired by the video acquisition unit 31 is stored as a series of moving images or as still images at predetermined time intervals. Along with the video, the video acquisition unit 31 also acquires date and time information indicating when the video was captured. 【0023】 ((Breaking Wave Analysis Department 32)) The wave breaking analysis unit 32 extracts wave breaking from the video acquired by the video acquisition unit 31 and analyzes the height of the extracted wave breaking. 【0024】 As mentioned above, wave breaking is a phenomenon that occurs when waves enter shallow waters from offshore, their wave height changes, and they break forward when the water depth approaches the wave height, resulting in turbulent motion. As shown in Figure 3, wave breaking consists of a lip P1, soup P2, face P3, and bottom P4. Lip P1 is the highest part of the wave. Soup P2 is the part where the wave breaks off from the lip P1 after it has cut upwards, and white foam is visible. Face P3 is the slope where the wave cuts upwards. Bottom P4 is the lowest horizontal part of the wave. 【0025】 First, the wave breaking analysis unit 32 extracts wave breaking from the video acquired by the video acquisition unit 31. The extraction method is not particularly limited, but for example, the wave breaking analysis unit 32 uses image processing to focus on the contrast between the white of the soup and the dark colors of the blue or black of the wavefronts (including the faces) adjacent to the soup, and extracts a predetermined rectangular region including the boundary between the soup and the wavefront as wave breaking. 【0026】 The wave breaking analysis unit 32 calculates the wave breaking height from the video acquired by the video acquisition unit 31. For example, as shown in Figure 4, the wave breaking analysis unit 32 sets a frame B as a predetermined rectangular area centered on the boundary between the soup portion and the wavefront, which constitute the extracted wave breaking. Frame B is, for example, a square or rectangular frame, with the center of the width corresponding to the boundary between the soup and the wavefront, and the height (length of the vertical arrows in the figure) corresponding to the distance from the bottom to the lip of the wave breaking. The height of frame B corresponds to the wave breaking height. The wave breaking analysis unit 32 calculates the height of frame B as the wave breaking height. 【0027】 The wave breaking analysis unit 32 analyzes the height of the extracted waves. For example, in the example shown in Figure 4, the wave breaking analysis unit 32 determines the height of the waves based on the height of frame B. 【0028】 For example, the wave breaking analysis unit 32 acquires information on the occurrence time of the extracted wave breaking. For example, if wave breaking is extracted 1 minute and 30 seconds after the start of video playback, the occurrence time of that wave breaking is 1 minute and 30 seconds. Hereafter, "○ minutes ○ seconds" will be simplified to "○:○" as appropriate. 【0029】 Furthermore, the information regarding the time of wave breaking may not be time information indicating how many minutes have passed since the start of video playback, but rather real-time information that takes into account the date and time the video was filmed. If the video analyzed by the wave breaking analysis unit 32 was filmed at 2 PM and the wave breaking is extracted 1 minute and 30 seconds after the start of playback, the extracted information regarding the time of wave breaking will be 2 PM, 1 minute, and 30 seconds. 【0030】 The wave breaking analysis unit 32 stores the extracted wave breaking time information and location information in the memory unit 22, linking it with the analyzed wave breaking height information. 【0031】 ((Surfer Analysis Department 33)) The surfer analysis unit 33 generates surfer information about surfers riding the breaking waves extracted by the breaking wave analysis unit 32. 【0032】 Surfer information refers to information describing the characteristics of a surfer riding a given wave. For example, it includes information on whether or not a surfer is riding the wave, the time from the start to the end of the ride, and an evaluation of the surfer riding the wave. Here, the surfer information generated by the surfer analysis unit 33 will be explained as information on whether or not a surfer is riding the wave. Other examples of surfer information will be described later. 【0033】 For example, the surfer analysis unit 33 extracts riding surfers in the breaking waves extracted by the breaking wave analysis unit 32. For example, if the breaking wave analysis unit 32 sets a frame B as a predetermined rectangular area centered on the boundary between the soup portion and the wavefront that constitute the extracted breaking waves, as shown in Figure 5, the surfer analysis unit 33 extracts riding surfers S inside frame B or within a predetermined range including frame B. The extraction method is not particularly limited, but for example, the surfer analysis unit 33 can extract riding surfers by using AI (Artificial Intelligence) to machine learn elements such as the shape of the circumscribing frame of the riding surfer and its area relative to the field of view. 【0034】 Then, the surfer analysis unit 33 determines, based on the results of extracting ride surfers, whether or not a surfer is riding the breaking wave extracted by the breaking wave analysis unit 32, and stores the determination result in the storage unit 22, linked to the information on the time of occurrence of the breaking wave. In the example in Figure 5, the surfer analysis unit 33 determines that surfer S is riding in frame B. 【0035】 The wave breaking analysis unit 32 and the surfer analysis unit 33 store the wave height linked to the time of wave occurrence information and the surfer information corresponding to that wave in the memory unit 22. Figure 6 is a table showing an example of information on wave height linked to the time of wave occurrence and whether or not a surfer is riding that wave (hereinafter referred to as "presence or absence of riding surfer"). In the example in Figure 6, it is shown that a wave with a height of 0.5m occurred at 1 minute and 30 seconds from the start of the video, and there is no riding surfer on that wave. In the example in Table 1, it is shown that a wave occurs every 10 seconds, and no new waves occurred between 3 minutes and 3 minutes and 30 seconds. 【0036】 ((Output processing unit 34)) The output processing unit 34 outputs the analysis results and information stored in the memory unit 22 to the wave breaking evaluation graph generation device 13 and the user terminal 14. For example, the output processing unit 34 outputs the wave breaking height and the presence or absence of surfers, which are linked to the wave breaking time information stored in the memory unit 22, to the wave breaking evaluation graph generation device 13. 【0037】 Although the aforementioned video analysis device 12 had the functions of both the wave-breaking analysis unit 32 and the surfer analysis unit 33, the device with the functions of the wave-breaking analysis unit 32 and the device with the functions of the surfer analysis unit 33 may be independent. 【0038】 ((Image analysis processing)) Next, the image analysis process of the video analysis device 12 will be explained with reference to the flowchart in Figure 7. 【0039】 In step S1, the video acquisition unit 31 acquires the video captured by the camera 11. 【0040】 In step S2, the wave breaking analysis unit 32 extracts a predetermined rectangular region from the video acquired by the video acquisition unit 31, which includes the boundary between the soup (the region where the waves break and become a white foamy substance) and the wavefront, as wave breaking. 【0041】 In step S3, the wave breaking analysis unit 32 analyzes the height of the extracted wave breaking. 【0042】 In step S4, the wave breaking analysis unit 32 stores the extracted wave breaking time and the wave breaking height information in the storage unit 22. 【0043】 In step S5, the surfer analysis unit 33 determines whether or not there are surfers riding the waves extracted by the wave breaking analysis unit 32, and stores the determination result in the memory unit 22, linked to the wave occurrence time information. 【0044】 In step S6, the output processing unit 34 outputs the information stored in the memory unit 22, including the time of wave breaking, the height of the waves, and whether or not there are surfers riding the waves, to the wave breaking evaluation graph generation device 13. 【0045】 The process will then be completed. 【0046】 In the above description, the analysis by the surfer analysis unit 33 was performed after the wave breaking analysis unit 32 performed the wave breaking analysis and stored the analysis results. However, the analysis by the surfer analysis unit 33 may be performed in parallel with the analysis by the wave breaking analysis unit 32. 【0047】 (Functional configuration of the wave breaking evaluation graph generation device 13) As shown in Figure 8, the wave breaking evaluation graph generation device 13 is configured to include a communication unit 41, a storage unit 42, and a control unit 43. 【0048】 The communication unit 41 communicates with the video analysis device 12 and the user terminal 14. The communication unit 41 may transmit various types of information using short-range wireless communication such as Bluetooth® or Wi-Fi®. Furthermore, it may exchange information with external servers and various services via a network (not shown) using wide-area wireless communication. 【0049】 The storage unit 42 includes, for example, ROM, RAM, and non-volatile memory. The storage unit 42 stores control application programs executed by the control unit 43, various data necessary for their execution, and information generated by processing. 【0050】 The control unit 43 consists of a CPU, memory (ROM, RAM, non-volatile memory, etc.), hardware, and other components. The control unit 43 controls the entire wave breaking evaluation graph generation device 13 by executing a control application program (not shown) stored in the memory unit 42, and also functions as an information acquisition unit 51, a presentation information generation unit 52, and an output processing unit 53. 【0051】 The information acquisition unit 51 receives information from the video analysis device 12 via the communication unit 41, including the time of wave breaking, wave height information, and information on whether or not there are surfers riding the waves, as surfer information related to surfers riding the waves. For example, the information acquisition unit 51 acquires the information shown in Figure 6. 【0052】 The information generation unit 52 generates graph-format information showing the wave height and surfer information for each time wave breaking occurs. 【0053】 The information generation unit 52 generates a graph from the information acquired by the information acquisition unit 51, with the horizontal axis representing the time of wave breaking and the vertical axis representing the height of the wave breaking. Figure 9 is an example of a graph generated by the information generation unit 52 based on the information in Figure 6 acquired by the information acquisition unit 51. For example, as shown in Figure 9, the information generation unit 52 generates a bar graph with the horizontal axis representing the time of wave breaking and the vertical axis representing the height of the wave breaking. If there are multiple waves breaking with the same time of occurrence, the information generation unit 52 may generate multiple overlapping bars in the bar graph, or it may use only the wave breaking with the highest height to generate the graph. 【0054】 The information generation unit 52 adds surfer information about surfers riding the waves, obtained from the information acquisition unit 51, to the generated graph. For example, the information generation unit 52 colors the bars in the generated bar graph that indicate surfers riding the waves. Figure 10 is a graph of Figure 9 in which the bars indicating surfers riding the waves are colored black based on the information acquired by the information acquisition unit 51 in Figure 6. Note that the coloring does not have to be black, and the information generation unit 52 may apply pattern fills such as checks or diagonal lines instead of coloring, or in addition to coloring. 【0055】 The output processing unit 53 outputs the graph generated by the presentation information generation unit 52 to the user terminal 14. The user can view the graph via the user terminal 14. 【0056】 ((Breakdown graph generation process)) Next, the wave breaking graph generation process of the wave breaking evaluation graph generation device 13 will be explained with reference to the flowchart in Figure 11. 【0057】 In step S11, the video analysis device 12 obtains information on the time of wave breaking, wave height, and whether or not there are surfers riding the waves. 【0058】 In step S12, the information generation unit 52 generates a bar graph from the information acquired by the information acquisition unit 51, with the horizontal axis representing the wave breaking time and the vertical axis representing the wave breaking height. 【0059】 In step S13, the information generation unit 52 adds surfer information corresponding to wave breaking, which is obtained by the information acquisition unit 51, to the generated graph. Specifically, the information generation unit 52 colors the bars in the generated bar graph that indicate wave breaking with surfers riding. 【0060】 In step S14, the output processing unit 53 outputs the graph generated by the presentation information generation unit 52 to the user terminal 14. 【0061】 The process will then be completed. 【0062】 [Other examples] (Other examples of video analysis devices) The wave-breaking analysis unit 32 of the video analysis device 12 may track wave breaking from the time of its occurrence until its disappearance. Specifically, the wave-breaking analysis unit 32 sets a rectangular region including the boundary between the soup and the wavefront from the time when the white of the soup can be detected due to the occurrence of wave breaking until the white of the soup can no longer be detected due to the disappearance of wave breaking, and tracks that rectangular region as a single wave breaking. The set rectangular region may change shape according to the change in the shape of the wave breaking. If the height of the wave breaking changes from the time of its occurrence until its disappearance, the wave-breaking analysis unit 32 may use the height at the time of the wave breaking as the height of the wave breaking, or it may use the highest height between the time of the wave breaking until its disappearance. 【0063】 (Other examples of surfer information) ((Ride time)) As described above, the information generation unit 52 added information about the presence or absence of a riding surfer to the graph as surfer information. However, surfer information is not limited to this; for example, it could also include information about the time from when a surfer starts riding a breaking wave until when they finish (hereinafter referred to as ride time). 【0064】 In this case, the surfer analysis unit 33 can analyze the ride time by tracking the surfer from the start to the end of the ride. For example, the start of the ride is when the surfer analysis unit 33 detects the surfer, and the end of the ride is when the surfer that the surfer analysis unit 33 was tracking is no longer detected. 【0065】 Figure 12 is a table showing an example of wave height, information on whether or not there were surfers riding the wave, and ride duration, all linked to the time of wave occurrence. The values ​​in the "Time of Wave Occurrence," "Wave Height," and "Surfers Riding" columns in Figure 12 are the same as those in Figure 6. 【0066】 Then, the presentation information generation unit 52 of the wave breaking evaluation graph generation device 13 adds ride time to the generated graph. For example, the presentation information generation unit 52 applies coloring or pattern filling to the graph using predetermined colors or patterns determined by the length of the ride time. Figure 13 is a graph showing the height of wave breaking at different time intervals, based on the information in Figure 12, with diagonal lines applied to the bars representing wave breaking corresponding to ride times of 1 to 9 seconds, and a checkered pattern filling applied to the bars representing wave breaking corresponding to ride times of 10 seconds or more. 【0067】 ((Ride rating)) Surfer information can also be based on evaluations from surfers who are riding the breaking waves. 【0068】 In this case, for example, the surfer analysis unit 33 evaluates the ride based on the ride time of the surfer, the height of the breaking wave the surfer is riding, and so on. 【0069】 For example, the surfer analysis unit 33 evaluates a ride as good if the ride time is long and the height of the waves being ridden is high. The surfer analysis unit 33 may also analyze the riding surfer's movements and evaluate a ride as good if the riding surfer performs certain movements. These movements may include, for example, the riding surfer suddenly changing direction or creating large splashes of water. The surfer analysis unit 33 may also provide graded evaluations such as "particularly good," "good," "average," and "not good." 【0070】 Then, the information generation unit 52 of the wave breaking evaluation graph generation device 13 adds ride evaluation information to the generated graph, similar to the ride time described above. For example, it applies coloring or pattern filling to the graph using predetermined colors or patterns determined by the evaluation results. 【0071】 (Adding a link) As described above, the information generation unit 52 added surfer information to the graph, but it may also add a link to jump to the video used by the video analysis unit for analysis. 【0072】 Specifically, the information generation unit 52 adds links to the data points of the generated graph. These links allow the video to be played by jumping to the time indicated by the horizontal axis of the data point. 【0073】 For example, in the example shown in Figure 9, the data points are each bar in the bar graph. The presentation information generation unit 52 adds a link to each bar to jump to a predetermined time in the video, and the output processing unit 53 outputs the graph with the links to the user terminal 14. 【0074】 Figure 14 shows an example of the display screen 61 of the user terminal 14. For example, the user terminal 14 displays a graph 71 and a video 72 used to generate the graph. If the user selects a bar on the horizontal axis, for example, indicated by an arrow, from the displayed graph 71, the video 72 will jump to the 2:30 mark and begin playback based on the link attached to the bar. 【0075】 (Other examples of graphs) As described above, the information generation unit 52 of the wave breaking evaluation graph generation device 13 generated a bar graph, but other types of graphs are also acceptable. For example, the information generation unit 52 can generate a line graph and color the plot points of the line graph. 【0076】 (Other examples of graph display) The output processing unit 53 outputs the graph generated by the presentation information generation unit 52 to the user terminal 14, and the user can view the graph via the user terminal 14. Other functions may be added to the graph displayed on the user terminal 14. 【0077】 For example, a user can zoom in on a graph by pinching out on the touch panel. The scale intervals of the graph may also change as the graph is zoomed in. 【0078】 (Specifying exclusion areas from which to extract wave breaks) As described above, the wave breaking analysis unit 32 of the video analysis device 12 extracted wave breaking from the video acquired by the video acquisition unit 31 and analyzed the height of the extracted wave breaking. In this case, the wave breaking analysis unit 32 may specify an exclusion region from the video acquired by the video acquisition unit 31 from which wave breaking should not be extracted, and extract wave breaking from the video excluding the exclusion region. 【0079】 For example, the wave-breaking analysis unit 32 designates areas where wave breaking cannot occur or areas where the analysis results may contain noise (e.g., near artificial structures such as breakwaters, and at the waterline) as excluded areas. For example, in the example shown in Figure 15, the wave-breaking analysis unit 32 designates offshore area R1 where wave breaking cannot occur, breakwater area R2, and waterline area R3, which is prone to generating white noise, as excluded areas. 【0080】 The exclusion zone can be specified manually or automatically. For example, the wave breaking analysis unit 32 can specify elements such as artificial structures on breakwaters as exclusion zones by using AI-based machine learning. Also, when specifying offshore areas where wave breaking is unlikely to occur as exclusion zones, the exclusion zone may be initially specified manually, and then automatically modified based on tide prediction information. 【0081】 (Method for calculating wave breaking height) In the example shown in Figure 4 above, the wave breaking analysis unit 32 calculated the height of frame B as the wave breaking height. However, in the case of gentle-slope waves (thicker waves) commonly found on coastlines throughout Japan, including Shonan, the wave breaking height shown in the video may differ from the actual wave breaking height. 【0082】 Therefore, in order to correct for this difference, the wave breaking analysis unit 32 calculates the actual height of the extracted wave breaking (hereinafter referred to as the actual wave height) H true This can also be calculated using the following formulas (1) and (2). H app =H img ×tanθ×cosθ···(1) H true =H app ×cosθ·······(2) H imgis the height of the breaking wave on the video (hereinafter, the wave height on the video as appropriate), and in the example of FIG. 4, it corresponds to the height of frame B. H app (H apparent ) is the apparent height of the breaking wave (hereinafter, appropriately referred to as the apparent wave height), and θ is the angle between the line of sight from the camera 11 that captured the video to the lip of the breaking wave and the sea surface. The wave height H on the video img is obtained in pixel units from the video and is converted to meter units according to the camera 11. θ can be calculated using the following formula (3). θ = arctan(distance A1C1 / distance A1B1) ··· (3) 【0083】 FIG. 16 is a diagram showing an example of the positional relationship between the camera 11 and the breaking wave. Point A1 is the intersection of the perpendicular line from the camera 11 and the sea surface, point A2 is the position of the bottom of the breaking wave, point B1 is the intersection of the line of sight from the camera 11 to the lip of the breaking wave and the sea surface, point C1 is the installation position of the camera 11, and point C2 is the intersection of the perpendicular line from the lip of the breaking wave and the sea surface. In FIG. 16, the wave height H on the video img corresponds to the distance A2B1, and the apparent wave height H app corresponds to the distance A2C2. 【0084】 The breaking wave analysis unit 32 previously obtains the angle θ between the line of sight from the camera 11 that captured the video to the lip of the breaking wave and the sea surface, and the wave height H on the video from the video img And the breaking wave analysis unit 32 calculates the actual wave height H true using the above formulas (1) and (2). 【0085】 A in FIG. 17 is a diagram for explaining the difference between the apparent wave height H app and the actual wave height H true when the camera 11 for capturing the video is installed at a low position, and B in FIG. 17 is a diagram for explaining the difference between the apparent wave height H app and the actual wave height H true when the camera 11 for capturing the video is installed at a high position. As shown in FIG. 17, when the camera 11 for capturing the video is installed at a high position, the apparent wave height H app and the actual wave height Htrue The difference becomes significant. Therefore, the correction effect of the calculation method described above is particularly pronounced when the camera 11 that captures the video is installed at a high position. 【0086】 (Determining the reliability of video analysis) As described above, the wave-breaking analysis unit 32 of the video analysis device 12 extracted wave breaks from the video acquired by the video acquisition unit 31 and analyzed the height of the extracted wave breaks. At that time, the wave-breaking analysis unit 32 may determine the reliability of the analysis result based on the quality of the video acquired by the video acquisition unit 31. 【0087】 If the video quality used by the wave-breaking analysis unit 32 for analysis is poor, the analysis result of wave-breaking height may differ from the actual result, reducing the reliability of the analysis result. Therefore, the wave-breaking analysis unit 32 determines the reliability based on the video quality and presents the reliability to the user along with the analysis result, so that the user can know in advance that the analysis result may differ from the actual result if the reliability is low. 【0088】 Specifically, the wave breaking analysis unit 32 evaluates the quality of the video acquired by the video acquisition unit 31. For example, the wave breaking analysis unit 32 may assign a score from "0" to "3" to the video based on predetermined items that affect the video quality. Here, a higher score indicates worse quality. The evaluation of video quality may be performed by a person visually inspecting the video, or it may be performed automatically. The wave breaking analysis unit 32 may also automatically evaluate the video quality by using AI and machine learning. 【0089】 For example, the specified items include "backlight," "darkness," "water droplets," "haze," and "choppy." For example, as shown in Figure 18A, if there is strong backlighting, the reflection on the water surface becomes strong and the image becomes unclear, so the score in the "backlight" item will be high. As shown in Figure 18B, if the weather is bad and there is insufficient sunlight, the image becomes dark and unclear, so the score in the "darkness" item will be high. As shown in Figure 19A, if water droplets are reflected on the camera lens due to rain, etc., they become noise in the image analysis, so the score in the "water droplets" item will be high. As shown in Figure 19B, if there is a lot of haze, the image becomes unclear, so the score in the "haze" item will be high. As shown in Figure 20, if there is a strong wind, the wave front shape becomes distorted (choppy), which becomes noise in the image analysis, so the score in the "choppy" item will be high. 【0090】 Next, the wave breaking analysis unit 32 determines the reliability of the video in four stages, from "A" to "D," based on the sum of the video scores for predetermined items that affect the quality of the video. Here, a reliability of "A" indicates that the video quality is good and the reliability of the video analysis results is high. 【0091】 For example, the wave breaking analysis unit 32 determines the confidence level to be "A" if the sum of the scores for each item is "0" or "1", "B" if the sum of the scores is "2" or "3", "C" if the sum of the scores is "4", and "D" if the sum of the scores is "5" or higher. 【0092】 For example, if the score for "backlight" is "0", the score for "darkness" is "3", the score for "water droplets" is "0", the score for "haze" is "1", and the score for "choppy" is "1", the total value is "5", so the confidence level is "D". 【0093】 The output processing unit 34 then outputs the reliability level determined by the wave breaking analysis unit 32 to the wave breaking evaluation graph generation device 13. The wave breaking evaluation graph generation device 13 then adds the reliability level information of the video analysis to the displayed information and outputs the displayed information including the reliability level to the user terminal 14. The user can find out the reliability level of the video analysis via the user terminal 14, and can know in advance that if the reliability level is low, the analysis results may differ from reality. 【0094】 The reliability of the video analysis determined by the wave-breaking analysis unit 32 may be stored in the video analysis device 12 or the wave-breaking evaluation graph generation device 13 along with the analysis results, and may be used as a reference value when reusing the video or analysis results. 【0095】 (Example where the video analysis device 12 is not used) As described above, the information acquisition unit 51 of the wave breaking evaluation graph generation device 13 acquired information from the video analysis device 12, but this is not limited to that. For example, another device may measure the height of the waves by image analysis, a person may visually determine the presence or absence of surfers, and the information acquisition unit 51 may acquire the manually or semi-automatically generated information. 【0096】 [Supplementary explanation of the embodiment] The embodiments described above are all preferred examples of the present invention. The numerical values, components, arrangement positions and connection configurations of the components, and processing order in the flowcharts shown in the embodiments are examples only and are not intended to limit the present invention. Furthermore, the figures are not necessarily strictly illustrative. 【0097】 The series of processes described above can be executed by hardware or by software. When the series of processes are executed by software, the programs that make up the software are installed from a program storage medium onto a computer that is built into dedicated hardware, or onto an information processing device such as a general-purpose personal computer that can perform various functions by installing various programs. 【0098】 The programs executed by the computer may be programs that are processed chronologically in the order described herein, or they may be programs that are processed in parallel or at necessary times, such as when a call is made. 【0099】 Furthermore, the embodiments of the present invention are not limited to those described above, and various modifications are possible without departing from the spirit of the invention. 【0100】 [Note] The contents described in some of the embodiments above can be understood, for example, as follows: 【0101】 (1) Graph showing wave height and surfer information The above-mentioned wave breaking evaluation graph generation device 13 (Figure 8) is, An information acquisition unit 51 acquires information on the time of wave breaking, the height of the wave breaking, and surfer information regarding surfers riding the wave. A presentation information generation unit 52 generates presentation information in graph format that shows the height of the wave breaking and the surfer information for each time the wave breaking occurs, It is equipped with. 【0102】 The information generation unit 52 generates graph-format information showing the wave height and surfer information for each time wave break occurs, so that users viewing the graph can easily understand the relationship between wave height and surfer information. 【0103】 (2) Graph format The aforementioned presentation information generation unit 52 is: The information acquisition unit 51 generates a graph (Figure 9) with the wave breaking time information acquired by the information acquisition unit 51 on the horizontal axis and the wave breaking height acquired by the information acquisition unit 51 on the vertical axis. The surfer information is added to the graph (Figure 10). 【0104】 With this configuration, the information generation unit 52 can generate information that integrates wave height and surfer information, allowing users viewing the graph to easily understand the relationship between wave height and surfer information. 【0105】 (3) Presence or absence of ride surfers The surfer information refers to whether or not a surfer is riding the breaking wave (Figures 6, 9, 10). 【0106】 Users viewing the graph can easily understand the relationship between wave height and the presence or absence of surfers. Furthermore, users can determine the height of the waves they were riding based on the time they spent riding them. 【0107】 (4) Ride time The surfer information refers to the time from when the surfer started riding the breaking wave until when they finished (Figures 12, 13). 【0108】 Users viewing the graph can easily understand the relationship between wave height and ride time. Furthermore, users can see a summary of the wave height and ride time they experienced, based on the total time they spent riding the waves. 【0109】 (5) Ride evaluation The surfer information mentioned above is an evaluation of the surfer riding the breaking waves. 【0110】 Users viewing the graph can easily understand the relationship between wave height and surfer ratings. For example, users can see the wave height at which good rides occurred. Furthermore, users can see a summary of the wave height at which they rode a wave and their rating of that ride, based on the time they spent riding it. 【0111】 (6) Bar graphs and coloring The information generation unit 52 generates a bar graph and colors the bars of the generated bar graph based on the surfer information (Figures 9 and 10). 【0112】 The wave breaking evaluation graph generator 13 can generate integrated information of wave breaking height and surfer information while maintaining a simple appearance by coloring the graph based on surfer information. 【0113】 (7) Wavebreaking evaluation graph generation system The above-mentioned wave breaking evaluation graph generation system is The system includes a video analysis device 12 and a wave breaking evaluation graph generation device 13. The aforementioned video analysis device 12 (Figure 2) The video acquisition unit 31 acquires video footage of a landscape including the water surface area where wave breaking can occur, The wave breaking analysis unit 32 extracts the wave breaking from the video acquired by the video acquisition unit 31 and analyzes the height of the extracted wave breaking, A surfer analysis unit 33 generates surfer information relating to surfers riding the waves extracted by the wave breaking analysis unit, The output processing unit 34 outputs the time of wave break, wave height information, and surfer information regarding surfers riding the waves, extracted by the wave break analysis unit 32, to the wave break evaluation graph generation device. It is equipped with. 【0114】 The wave-breaking evaluation graph generation system obtains wave height information and surfer information from video footage, allowing it to generate a graph for all waves included in the video. 【0115】 (8) Links with video The information acquisition unit 51 acquires the video acquired by the video acquisition unit 31, The aforementioned presentation information generation unit 52 is: The information acquisition unit 51 generates a graph with the wave breaking time information acquired by the information acquisition unit on the horizontal axis and the wave breaking height acquired by the information acquisition unit on the vertical axis. The surfer information is added to the graph, Links are further added to the data points of the generated graph. The aforementioned link is for playing the video by jumping to the time indicated by the horizontal axis of the data point (Figure 14). 【0116】 This configuration allows users who view the graph to access video footage including the graphed wave breaking via a link, making it easier to understand the wave breaking conditions during a given time period. Users can view video footage of the waves they were riding based on the time they were surfing, retrieve the video footage they took, and easily review the time they were in the water. 【0117】 (9) Specifying exclusion areas from which wave breaking should not be extracted The wave breaking analysis unit 32 specifies an exclusion region from the video acquired by the video acquisition unit 31 from which wave breaking should not be extracted, and extracts the wave breaking from the video excluding the exclusion region. 【0118】 With this configuration, the wave breaking analysis unit 32 can specify areas in the video where wave breaking cannot occur, or areas where the analysis results may contain noise (for example, near artificial structures such as breakwaters, or at the waterline), as exclusion areas, thereby preventing the detection of abnormal wave breaking and the generation of abnormal values ​​for wave breaking height. 【0119】 (10) Method for calculating wave breaking height The wave breaking analysis unit 32 extracts the wave breaking height H true This is calculated using the following formulas (1) and (2). H app =H img ×tanθ×cosθ···(1) H true =H app ×cosθ·······(2) H img H is the height of the waves breaking in the video. appθ is the apparent height of the breaking wave, and θ is the angle between the line of sight from the camera 11 that captured the video, looking at the lip of the breaking wave, and the sea surface. 【0120】 When the camera 11 that captures the video is installed at a high position, the height of the waves shown in the video may differ from the actual height of the waves, especially in the case of gentle-sloping waves (thicker waves) commonly seen on coastlines throughout Japan, including Shonan. Therefore, this configuration allows the perspective-corrected height of the waves shown in the video to be corrected to match the actual height of the waves. 【0121】 (11) Video quality assessment The wave breaking analysis unit 32 determines the reliability of the analysis result based on the quality of the video acquired by the video acquisition unit 31. The output processing unit 34 can output the reliability determined by the wave breaking analysis unit 32 to the wave breaking evaluation graph generation device. 【0122】 If the video quality used by the wave-breaking analysis unit 32 for analysis is poor, the analysis result of wave-breaking height may differ from the actual value, reducing the reliability of the analysis result. Therefore, the wave-breaking analysis unit 32 can determine the reliability based on the video quality and output the reliability to the wave-breaking evaluation graph generation device, thereby presenting the reliability to the user. The user can then know in advance that if the reliability is low, the analysis result may differ from the actual value. [Explanation of Symbols] 【0123】 1 ride time 11 Cameras 12. Video analysis device 13 Wavebreaking Evaluation Graph Generator 14 User terminals 21 Communications Department 22 Memory section 23 Control Unit 31 Video Acquisition Unit 32 Breaking wave analysis department 33 Surfer Analysis Department 34 Output Processing Unit 41 Communications Department 42 Storage section 43 Control Unit 51 Information Acquisition Department 52 Presentation information generation unit 53 Output Processing Unit

Claims

[Claim 1] An information acquisition unit that acquires information on the time of wave breaking, the height of the wave breaking, and surfer information regarding surfers riding the wave, A presentation information generation unit generates presentation information in graph format that shows the height of the wave breaking and the surfer information for each time the wave breaking occurs. A wave-breaking evaluation graph generation device characterized by comprising the following features. [Claim 2] A wave breaking evaluation graph generation device according to claim 1, The aforementioned information generation unit, The information acquisition unit generates a graph with the wave breaking time information acquired by the information acquisition unit on the horizontal axis and the wave breaking height acquired by the information acquisition unit on the vertical axis. The surfer information is added to the graph. A wave-breaking evaluation graph generation device characterized by the following features. [Claim 3] A wave breaking evaluation graph generation device according to claim 1, The surfer information refers to whether or not a surfer is riding the breaking waves. A wave-breaking evaluation graph generation device characterized by the following features. [Claim 4] A wave breaking evaluation graph generation device according to claim 1, The surfer information refers to the time from when the surfer started riding the breakwater until when they finished. A wave-breaking evaluation graph generation device characterized by the following features. [Claim 5] A wave breaking evaluation graph generation device according to claim 1, The surfer information mentioned above is an evaluation of the surfer riding the breaking waves. A wave-breaking evaluation graph generation device characterized by the following features. [Claim 6] A wave breaking evaluation graph generating apparatus according to any one of claims 3 to 5, The information generation unit generates a bar graph and colors the bars of the generated bar graph based on the surfer information. A wave-breaking evaluation graph generation device characterized by the following features. [Claim 7] A wave breaking evaluation graph generation system comprising a video analysis device and a wave breaking evaluation graph generation device according to claim 1, The aforementioned video analysis device is A video acquisition unit that acquires video footage of a landscape including the water surface area where waves may break, A wave breaking analysis unit extracts the wave breaking from the video acquired by the video acquisition unit and analyzes the height of the extracted wave breaking, A surfer analysis unit generates surfer information relating to surfers riding the waves extracted by the wave breaking analysis unit, An output processing unit outputs the time of wave break, wave height information, and surfer information relating to surfers riding the waves, extracted by the wave break analysis unit, to the wave break evaluation graph generation device. A wave-breaking evaluation graph generation system characterized by comprising the following features. [Claim 8] A wave breaking evaluation graph generation system according to claim 7, The information acquisition unit acquires the video acquired by the video acquisition unit, The aforementioned information generation unit, The information acquisition unit generates a graph with the wave breaking time information acquired by the information acquisition unit on the horizontal axis and the wave breaking height acquired by the information acquisition unit on the vertical axis. The surfer information is added to the graph, Links are further added to the data points of the generated graph. The aforementioned link is for playing the video by jumping to the time indicated by the horizontal axis of the data point. A wave-breaking evaluation graph generation system characterized by the following features. [Claim 9] A wave breaking evaluation graph generation system according to claim 7, The wave breaking analysis unit specifies an exclusion region from the video acquired by the video acquisition unit in which wave breaking should not be extracted, and extracts the wave breaking from the video excluding the exclusion region. A wave-breaking evaluation graph generation system characterized by the following features. [Claim 10] A wave breaking evaluation graph generation system according to claim 7, The wave breaking analysis unit extracts the wave breaking height H ｔｒｕｅ This is calculated using the following formulas (1) and (2). A wave-breaking evaluation graph generation system characterized by the following features. H ａｐｐ =H ｉｍｇ ×tanθ×cosθ・・・(1) H ｔｒｕｅ =H ａｐｐ ×cosθ ・・・・・・・(2) H ｉｍｇ H is the height of the wave breaking in the video. ａｐｐ θ is the apparent height of the wave breaker, and θ is the angle between the line of sight of the lip of the wave breaker from the camera that captured the video and the sea surface. [Claim 11] A wave breaking evaluation graph generation system according to claim 7, The wave breaking analysis unit determines the reliability of the analysis result based on the quality of the video acquired by the video acquisition unit. The output processing unit outputs the reliability determined by the wave breaking analysis unit to the wave breaking evaluation graph generation device. A wave-breaking evaluation graph generation system characterized by the following features. [Claim 12] An information acquisition step involves acquiring information on the time of wave breaking, the height of the wave breaking, and surfer information regarding surfers riding the wave. A presentation information generation step generates presentation information in graph format that shows the height of the wave breaking and the surfer information for each time the wave breaking occurs. A method for generating a wave breaking evaluation graph, characterized by including the following: [Claim 13] In a program that can be executed by a computer capable of exchanging information with an input / output device, An information acquisition step involves acquiring information on the time of wave breaking, the height of the wave breaking, and surfer information regarding surfers riding the wave. A presentation information generation step generates presentation information in graph format that shows the height of the wave breaking and the surfer information for each time the wave breaking occurs. A program that causes a computer to perform a process, characterized by including [a certain element].

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