A video wave measurement method and system for wave tank model experiments

Abstract

The present invention discloses a video wave measurement method and system for wave tank model experiments. The method comprises: acquiring a video image of water surface fluctuations in a wave tank, identifying the water body in the video image, and obtaining a boundary line between the water body and the air above; setting a number of observation lines perpendicular to the bottom of the wave tank in the video image, and obtaining the intersection points of each observation line with the boundary line; sequentially connecting the intersection points of each observation line with the boundary line on a time axis to obtain water surface fluctuation lines, and calculating wave elements based on the water surface fluctuation lines. The system comprises an identification module, an observation line module, and a calculation module. This method implements video wave measurement in a wave tank model experiment.

Description

Technical Field

[0001] The present invention relates to the field of wave measurement technology, and in particular to a video wave measurement method and system for wave tank model experiments. Background Art

[0002] Ports and marine engineering structures are typically located in coastal areas and are frequently subject to the damaging effects of coastal dynamics such as waves and currents. Therefore, physical model tests in wave tanks are frequently required. Based on the principle of similarity, by reducing the scale, relevant phenomena of the prototype can be replicated in the model, making it more intuitive and easier to study.

[0003] According to the experimental needs, regular waves or irregular waves are first generated by a wave maker. After the waves pass through the water tank, the wave height and period change. Usually, a capacitive wave height meter is used to measure the changed wave height and period and other factors.

[0004] Capacitive wave height sensors use a contact-based observation method. Their drawbacks include potential for electromagnetic interference and increased corrosion damage in high-salinity water. Furthermore, they can only observe surface fluctuations at the sensor's location. Observing wave height changes at multiple locations requires multiple capacitive wave height sensors. This results in high observation costs and significant data errors.

[0005] The purpose of the present invention is to design a video wave measurement method and system for wave tank model experiments in order to solve the problems existing in the prior art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a video wave measurement method and system for wave tank model experiments, which can solve the above problems.

[0007] The present invention provides a video wave measurement method for a wave tank model experiment, comprising:

[0008] Acquire a video image of water surface fluctuations in a wave tank, identify a water body in the video image, and obtain a boundary line between the water body and the air;

[0009] Setting a plurality of observation lines perpendicular to the bottom of the wave tank in the video image, and obtaining an intersection point of each observation line with a boundary line;

[0010] The intersection points of each observation line and the boundary line are connected in sequence on the time axis to obtain the water surface fluctuation line, and the wave elements are calculated through the water surface fluctuation line.

[0011] Furthermore, the identifying of the water body in the video image and obtaining the boundary line between the water body and the air includes:

[0012] Construct the image segmentation model through the YOLO series model;

[0013] Collect video images of water surface fluctuations in a wave tank and the corresponding water and air boundary positions as training and validation sets;

[0014] Using the video image of the water surface fluctuations of the wave tank as the input of the image segmentation model and the position of the boundary line as the output of the image segmentation model, training the image segmentation model to obtain parameters of the image segmentation model;

[0015] The water body in the video image is identified by the trained image segmentation model to obtain a boundary line between the water body and the air.

[0016] Furthermore, the setting of a plurality of observation lines perpendicular to the bottom of the wave tank in the video image includes:

[0017] Each of the observation lines is arranged at equal intervals.

[0018] Furthermore, the step of sequentially connecting the intersection points of each observation line and the boundary line on the time axis to obtain the water surface fluctuation line includes:

[0019] Each of the water surface fluctuation lines corresponds to a fluctuation process of the intersection point, and each of the water surface fluctuation lines contains several waves.

[0020] Furthermore, the calculation of wave elements by water surface wave lines includes:

[0021] Calculating the actual height of the water surface fluctuation line;

[0022] The wave element is calculated according to the actual height of the water surface wave line.

[0023] Further, the calculating the actual height of the water surface fluctuation line includes:

[0024] Calculating a corresponding ratio based on the height difference between the bottom and the top of the water tank and the number of pixels at the bottom and the top of the water tank in the video image;

[0025] The actual height is obtained by converting the corresponding ratio and the number of pixels of the water surface fluctuation line.

[0026] Furthermore, the calculating of the wave element according to the actual height of the water surface wave line includes:

[0027] Calculating the wave height and period of each wave on the water surface wave line;

[0028] The maximum wave height, the maximum wave period, the wave height of one-tenth of a large wave, the wave height of one-tenth of a large wave, the wave height of a significant wave, and the significant wave period are calculated according to the wave height and period of each wave on the water surface wave line.

[0029] Further, the calculating the wave height and period of each wave on the water surface wave line includes:

[0030] The vertical distance between a significant wave crest and a significant wave trough between two adjacent upper span or lower span zero points is measured as the wave height H of a wave;

[0031] The time interval between two adjacent significant wave peaks or two zero crossings is measured as the period of a wave.

[0032] Furthermore, the maximum wave height, maximum wave period, 1 / 10 maximum wave height, and effective wave height are calculated based on the wave height and period of each wave on the water surface wave line:

[0033] sorting all waves on the water surface wave line according to the wave heights, and selecting the first 100 waves;

[0034] The maximum value of all wave heights is selected as the maximum wave height, and the period corresponding to the wave with the maximum wave height is the maximum wave period;

[0035] The average of the first 1 / 10 of the wave heights is selected to obtain the 1 / 10 wave height;

[0036] The average value of the first 1 / 3 of the wave heights is selected to obtain the significant wave height.

[0037] The present invention provides a video wave measurement system for wave tank model experiments, comprising:

[0038] an identification module, configured to obtain a video image of water surface fluctuations in a wave tank, identify a water body in the video image, and obtain a boundary line between the water body and the air;

[0039] An observation line module, configured to set a plurality of observation lines perpendicular to the bottom of the wave tank in the video image, and obtain an intersection point of each observation line with a boundary line;

[0040] The calculation module is used to connect the intersection points of each observation line and the boundary line in sequence on the time axis to obtain a water surface fluctuation line, and calculate the wave elements through the water surface fluctuation line.

[0041] Beneficial effects of the present invention:

[0042] First, by obtaining a video image of the water surface fluctuations in a wave tank, the water body in the video image is identified, and the boundary line between the water body and the air is obtained; there is no need to set up various sensors in the tank to collect data, which saves experimental costs. Only a camera needs to be set up on the side of the tank for shooting and recording to obtain a video image of the water surface fluctuations in the wave tank. The video image is used to obtain the boundary line between the water body and the air, which facilitates the subsequent determination of the water surface fluctuation line and the calculation of wave elements.

[0043] The second is to set several observation lines perpendicular to the bottom of the wave tank in the video image to obtain the intersection of each observation line and the boundary line; the water surface fluctuation line can be obtained quickly and accurately by using the intersection of the observation line and the boundary line, and several observation points on the water surface fluctuation line can be directly obtained without setting up additional sensors to collect wave data.

[0044] The third is to connect the intersection points of each observation line and the boundary line in sequence on the time axis to obtain the water surface fluctuation line, and calculate the wave elements through the water surface fluctuation line; based on the information on the water surface fluctuation line, the wave element data at different observation positions at different times can be quickly calculated, and the statistical wave element data can be used to verify and analyze the changes and laws of waves during the propagation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 It is a flow chart of the method of this embodiment.

[0047] Figure 2 Schematic diagram of the water tank and video installation in this embodiment.

[0048] Figure 3 1 is a schematic diagram of a video image of water surface fluctuations in the wave tank of this embodiment.

[0049] Figure 4 Schematic diagram of the observation line and the intersection of the observation line and the water surface line in this embodiment.

[0050] Figure 5 It is a schematic diagram of the statistical method of wave elements in this embodiment.

[0051] Figure 6 It is a system module diagram of this embodiment. DETAILED DESCRIPTION

[0052] To facilitate understanding by those skilled in the art, the structure of the present invention will now be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the steps mentioned in this embodiment, unless otherwise specified, can be adjusted in sequence according to actual needs, and can even be executed simultaneously or partially simultaneously.

[0053] like Figure 1 As shown, an embodiment of the present invention provides a video wave measurement method for a wave tank model experiment, comprising:

[0054] S1 obtains a video image of water surface fluctuations in a wave tank, identifies a water body in the video image, and obtains a boundary line between the water body and the air;

[0055] In this step, during the wave tank model experiment, if Figure 2 As shown, the wave generator is installed on one side of the wave tank. A high-definition video camera is mounted horizontally at a suitable location on the side of the wave tank (where the entire wave tank can be captured). This captures video images of the water surface fluctuations in the wave tank, transmits the video signal to a computer, and saves it there. To improve video clarity and observation quality, the high-definition video camera should have a resolution of 8 megapixels or higher.

[0056] S101 constructs the image segmentation model through the YOLO series model;

[0057] S102 collects video images of water surface fluctuations in a wave tank and the corresponding water and air boundary positions as training and validation sets;

[0058] S103 uses the video image of the water surface fluctuations of the wave tank as the input of the image segmentation model and the boundary line position as the output of the image segmentation model, trains the image segmentation model, and obtains parameters of the image segmentation model;

[0059] S104 identifies the water body in the video image through the trained image segmentation model to obtain a boundary line between the water body and the air.

[0060] In this step, if Figure 3 As shown, the water and air boundary positions are annotated on the video images of the water surface fluctuations collected from the wave tank and used as the training and validation sets for the image segmentation model. The YOLO series model is a YOLOv8 deep learning model, which performs fast and accurate simulation training. The training and validation sets contain no fewer than 100 examples, and the training cycles are no fewer than 400. The accuracy of the water and air boundary position recognition in this embodiment exceeds 98%. The use of the YOLOv8 deep learning model can greatly improve the accuracy of image recognition and lower the threshold for training and deployment.

[0061] The successfully trained image segmentation model is used to identify the water body in the video image, obtaining the boundary between the water body and the air above. Compared to traditional methods that simply process images using R, G, and B color separation, grayscale processing, binarization, and Gaussian kernel filtering, this method of identifying water bodies using a deep learning model is more efficient and accurate in processing transparent water bodies, water bodies with reflective glass in tanks, and water bodies with complex background colors. It also eliminates the need to add color indicators to the water.

[0062] S2 sets a plurality of observation lines perpendicular to the bottom of the wave tank in the video image, and obtains the intersection of each observation line and the boundary line;

[0063] In this step, if Figure 4 As shown, the boundary line between water and air is the line connecting the heights of water surfaces at different positions at a certain moment. What is needed to calculate wave elements is the line connecting the heights of water surfaces at the same position at different moments. Therefore, multiple vertical observation lines are set at the positions where waves need to be observed in the video image. Each observation line is arranged at equal intervals, and the number of observation lines is set according to the actual sampling needs. For example: if the length of the water tank is 5m, an observation line can be set at intervals of 1m, and the changes in waves within a range of 5m can be studied. The intersection points of the observation lines and the above-mentioned boundary lines are numbered as: P0, P1, P2...P n .

[0064] S3 connects the intersection points of each observation line and the boundary line in sequence on the time axis to obtain the water surface fluctuation line, and calculates the wave elements through the water surface fluctuation line.

[0065] In this step, since the boundary line between water and air is the line connecting the water surface heights at different positions at a certain moment, the wave element calculation requires the line connecting the water surface heights at the same position at different moments. The position of the intersection point Pi of each observation line and the boundary line changes with time, so the intersection points P0, P1, P2...P on the video image are arranged in chronological order. n Connect the water surface wave lines L0, L1, L2...L in sequence n , each of the water surface fluctuation lines L i Corresponding to one of the intersection points P i The fluctuation process, each of the water surface fluctuation lines L i Contains several waves.

[0066] Specifically, the calculation of wave elements using water surface wave lines includes:

[0067] S301 calculates the actual height of the water surface fluctuation line;

[0068] S3011 calculates a corresponding ratio based on the height difference between the bottom and the top of the water tank and the number of pixels at the bottom and the top of the water tank in the video image;

[0069] S3012 converts the actual height according to the corresponding ratio and the number of pixels of the water surface fluctuation line.

[0070] In this step, a correspondence is formed between the measured height difference data of the bottom and top of the sink and the pixel points between the top and bottom of the sink in the video image, and the position height of the water surface fluctuation line is converted into the actual height from the bottom of the sink in cm. The height difference between the bottom and top of the sink in this example is 1000mm, and the number of pixels on the corresponding image is 500, so the corresponding conversion relationship is 1 pixel represents 2mm. The resolution and error of the deep learning model algorithm reach the pixel level, which means that the recognition error of the water surface fluctuation line in the example is 2mm. If a higher resolution camera is used, if the number of pixels of the sink on the image can reach 1000, under good light and high video quality conditions, the resolution and error can reach 1mm. The accurate calculation of the actual height of each wave of the water surface fluctuation line can be achieved.

[0071] S302 calculates the wave element according to the actual height of the water surface wave line.

[0072] S3021 calculates the wave height and period of each wave on the water surface wave line;

[0073] S30211 The vertical distance between a significant wave crest and a significant wave trough between two adjacent upper span or lower span zero points is measured as the wave height H of a wave;

[0074] S30212 measures the time interval between two adjacent significant wave peaks or two zero crossings as the period of a wave.

[0075] S3022 calculates the maximum wave height, the maximum wave period, the tenth wave height, and the significant wave height according to the wave height and period of each wave on the water surface wave line.

[0076] S30221 sorts all waves on the water surface wave line according to the wave heights, and selects the first 100 waves;

[0077] S30222 selects the maximum value of all wave heights as the maximum wave height, and the period corresponding to the wave with the maximum wave height is the maximum wave period;

[0078] S30223 selects the average of the first 1 / 10 of the wave heights to obtain the 1 / 10 largest wave height;

[0079] S30224 selects the average value of the first 1 / 3 of the wave heights to obtain the effective wave height.

[0080] In this step, because wave element calculation requires data from at least 100 waves, we need to acquire at least 100 waves from the water surface wave line. The length of the video recording depends on the average period. In this example, if the average wave period is 5 seconds, 100 waves require at least 500 seconds, or approximately 8.33 minutes, to acquire 100 waves. Therefore, we actually acquire 10 minutes of video data.

[0081] According to the statistical method of wave elements such as wave height and period in the standard "GB / T 12763.2-2007 Marine Survey Specification Part 2", the maximum wave height, maximum wave period, one-tenth of the wave height, significant wave height, average wave height, wavelength and other wave elements are calculated. The specific calculation process is as follows:

[0082] From the continuous record of the wave on the water surface wave line, measure the zero points of the two adjacent upper spans (or lower spans) ( Figure 5 The vertical distance between a significant wave crest and a significant wave trough (A1 and A2 are the upper crossing zero points) is taken as the wave height H of a wave; the vertical distance between two adjacent significant wave crests ( Figure 5 C1, C2) or the time interval between two zero crossings is regarded as the period of a wave.

[0083] Obtain all wave heights along the surface wave line, sort each wave height H from largest to smallest, select the top 100, and then calculate these wave elements based on the maximum wave height, maximum wave period, one-tenth of the major wave height, and the significant wave height. Specifically, the maximum value of all wave heights is selected as the maximum wave height, and its corresponding period is the maximum wave period; the average of the first 1 / 10 of the wave heights is taken to obtain the 1 / 10 major wave height; and the average of the first 1 / 3 of the wave heights is taken to obtain the significant wave height.

[0084] In addition, other wave elements such as average wave height and wavelength can be calculated using the statistical methods in the specification "GB / T 12763.2-2007 Marine Survey Specification Part 2", which will not be described in detail here.

[0085] The resulting wave elements, from the wave generator at the top of the flume to multiple observation locations at the end, can be used to verify and analyze the variations and patterns of wave propagation. Wave flume experiments typically observe the changes in significant wave height. By plotting the significant wave height variations for all observation locations, sorted by distance from the wave generator, from closest to farthest, the process lines can be plotted to visualize the changes in significant wave height as it propagates through the flume.

[0086] The following table compares the wave element data obtained by the capacitive wave meter wave measurement method and the wave element data obtained by the video wave measurement method in this embodiment:

[0087]

[0088] As can be seen, the results of wave elements Hs and Ts calculated using the video wave measurement method in this embodiment and the capacitance wave meter wave measurement method are basically consistent, with very little difference. The advantage of video is its convenience, allowing it to measure multiple points at once, while capacitance can only measure one point at a time, requiring multiple capacitance wave meters to measure multiple points.

[0089] like Figure 6As shown, an embodiment of the present invention provides a video wave measurement system for a wave tank model experiment, comprising:

[0090] an identification module, configured to obtain a video image of water surface fluctuations in a wave tank, identify a water body in the video image, and obtain a boundary line between the water body and the air;

[0091] An observation line module, configured to set a plurality of observation lines perpendicular to the bottom of the wave tank in the video image, and obtain an intersection point of each observation line with a boundary line;

[0092] The calculation module is used to connect the intersection points of each observation line and the boundary line in sequence on the time axis to obtain the water surface fluctuation line.

[0093] The video wave measurement system for wave tank model experiments has the same working principle as the above-mentioned video wave measurement method for wave tank model experiments.

[0094] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0095] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0096] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0098] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claim. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third etc. does not indicate any order. These words may be interpreted as names.

[0099] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0100] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

[0101] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0102] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

Claims

1. A video wave measurement method for wave tank model experiments, characterized in that: include: Obtain a video image of water surface fluctuations in a wave tank, identify the water body in the video image, and obtain the boundary line between the water body and the air. Specifically: Build an image segmentation model through the YOLO series model; Collect video images of water surface fluctuations in a wave tank and the corresponding water and air boundary positions as training and validation sets; Using the water surface fluctuation video image of the wave tank as the input of the image segmentation model and the boundary line position as the output of the image segmentation model, training the image segmentation model to obtain parameters of the image segmentation model; Identifying a water body in the video image using the trained image segmentation model to obtain a boundary line between the water body and the air; Setting a plurality of observation lines perpendicular to the bottom of the wave tank in the video image, with each observation line arranged at equal intervals, and obtaining an intersection point between each observation line and the boundary line; Connect the intersection points of each observation line and the boundary line on the time axis to obtain the water surface fluctuation line, and calculate the wave elements through the water surface fluctuation line. Specifically: Calculate the actual height of the water surface fluctuation line, specifically: Calculating a corresponding ratio based on the height difference between the bottom and the top of the water tank and the number of pixels at the bottom and the top of the water tank in the video image; The actual height is obtained by converting the corresponding ratio and the number of pixels of the water surface fluctuation line; The wave elements are calculated according to the actual height of the water surface wave line, specifically: Calculating the wave height and period of each wave on the water surface wave line; The maximum wave height, the maximum wave period, the height of one-tenth of the maximum wave, and the height of the significant wave are calculated according to the wave height and period of each wave on the water surface wave line.

2. The video wave measurement method for wave tank model experiment according to claim 1 is characterized in that: The step of sequentially connecting the intersection points of each observation line and the boundary line on the time axis to obtain a water surface fluctuation line comprises: Each of the water surface fluctuation lines corresponds to a fluctuation process of the intersection point, and each of the water surface fluctuation lines contains several waves.

3. The video wave measurement method for wave tank model experiment according to claim 1 is characterized in that: Calculating the wave height and period of each wave on the water surface wave line includes: The vertical distance between a significant wave crest and a significant wave trough between two adjacent upper span or lower span zero points is measured as the wave height of a wave; The time interval between two adjacent significant wave peaks or two zero crossings is measured as the period of a wave.

4. The video wave measurement method for wave tank model experiment according to claim 1 is characterized in that: Calculating the maximum wave height, the maximum wave period, the 1 / 10 wave height, and the effective wave height based on the wave height and period of each wave on the water surface wave line includes: sorting all waves on the water surface wave line according to the wave heights, and selecting the first 100 waves; The maximum value of all wave heights is selected as the maximum wave height, and the period corresponding to the wave with the maximum wave height is the maximum wave period; The average of the first 1 / 10 of the wave heights is selected to obtain the 1 / 10 wave height; The average value of the first 1 / 3 of the wave heights is selected to obtain the significant wave height.

5. A video wave measurement system for wave tank model experiments, characterized in that: The video wave measurement method for wave tank model experiments according to any one of claims 1 to 4 comprises: The recognition module is used to obtain a video image of water surface fluctuations in a wave tank, identify the water body in the video image, and obtain the boundary line between the water body and the air. Specifically, it is used to: Build an image segmentation model through the YOLO series model; Collect video images of water surface fluctuations in a wave tank and the corresponding water and air boundary positions as training and validation sets; Using the water surface fluctuation video image of the wave tank as the input of the image segmentation model and the boundary line position as the output of the image segmentation model, training the image segmentation model to obtain parameters of the image segmentation model; Identifying a water body in the video image using the trained image segmentation model to obtain a boundary line between the water body and the air; An observation line module is used to set a plurality of observation lines perpendicular to the bottom of the wave tank in the video image, wherein each of the observation lines is arranged at equal intervals, and obtain an intersection point of each observation line with a boundary line; The calculation module is used to connect the intersection points of each observation line and the boundary line in sequence on the time axis to obtain the water surface fluctuation line, and calculate the wave elements through the water surface fluctuation line. Specifically used for: Calculating the actual height of the water surface fluctuation line is specifically used for: Calculating a corresponding ratio based on the height difference between the bottom and the top of the water tank and the number of pixels at the bottom and the top of the water tank in the video image; The actual height is obtained by converting the corresponding ratio and the number of pixels of the water surface fluctuation line; Calculating the wave element according to the actual height of the water surface wave line is specifically used for: Calculating the wave height and period of each wave on the water surface wave line; The maximum wave height, the maximum wave period, the height of one-tenth of the maximum wave, and the height of the significant wave are calculated according to the wave height and period of each wave on the water surface wave line.

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