In-situ image acquisition device and method for seabed cold spring leakage bubbles and monitoring method

Abstract

The invention discloses an in-situ image acquisition device and method for seabed cold spring leakage bubbles and a monitoring method, and relates to the technical field of deep sea detection. The acquisition device comprises a first window arranged on the end face of a first pressure-resistant bin, and a visible light source and a first convex lens arranged in the first pressure-resistant bin; a second window is arranged on the end face of the second pressure-resistant bin, and a light field camera and a second convex lens are arranged in the second pressure-resistant bin; the two ends of the sampling column are fixedly connected with the first window and the second window respectively, and the sampling column is provided with a through equal-diameter channel in the radial direction. During image acquisition, the image acquisition device is carried on an ROV and transported to a deep sea cold spring leakage area, an equal-diameter channel of the sampling column is arranged above a selected target nozzle, the visible light source emits light rays, and the light rays are transmitted through the first convex lens, the first window, the sampling column, the second window, the second convex lens and the light field camera. And shooting according to a preset shooting interval time to obtain a plurality of original leakage bubble pictures. According to the monitoring method, a light field image reconstruction algorithm is utilized to obtain a corresponding leakage bubble reconstruction image, and then fine parameters such as the mass center position, the equivalent diameter, the migration rate and the volume flux of the leakage bubble are recognized and calculated. According to the invention, in-situ delivery can be realized, seabed cold spring leakage bubble images can be accurately obtained, and fine parameters of leakage bubbles can be monitored.

Description

Technical Field

[0001] The present invention relates to the technical field of deep sea exploration, and more specifically, to an in-situ image acquisition device, method and monitoring method for bubbles leaking from cold springs on the seafloor. Background Art

[0002] Seafloor cold seep gas leakage is a natural phenomenon that is widely distributed around the world. The leakage gases are mainly methane and hydrogen sulfide. Among them, methane leakage from seafloor cold seeps is an important source of atmospheric methane, and the vertical migration of seafloor methane seep bubbles has an important impact on global climate change. Therefore, accurate monitoring and flux assessment of seafloor seep methane and other bubbles is an important means to understand the impact of deep-sea seep gases on the ocean carbon cycle and global climate change.

[0003] At present, the measurement of submarine cold seepage bubbles mainly adopts technologies such as gas collectors, ultrasonic arrays, and multi-beam hydroacoustic scanning sonar. However, the above technical means all have their limitations, such as limited sampling volume and difficulty in in-situ deployment, which means that the existing technology can only estimate the flux of cold seepage bubbles, but it is difficult to calculate the key parameters of bubbles such as size, shape, and rise rate. Bubble size, shape, and rise rate are important factors affecting the migration and transformation of seepage bubbles in seawater, which are related to the reliability and accuracy of the assessment of submarine seepage methane on the ocean carbon cycle and global climate change. Summary of the invention

[0004] One of the purposes of the present invention is to provide an in-situ image acquisition device for submarine cold spring leakage bubbles, so as to overcome the defect that the above-mentioned prior art is difficult to be deployed in situ and accurately obtain the image of submarine cold spring leakage bubbles; the second purpose is to provide an in-situ image acquisition method for submarine cold spring leakage bubbles; the third purpose is to provide a monitoring method for submarine cold spring leakage bubbles, so as to overcome the defect that the above-mentioned prior art is difficult to monitor the fine parameters of submarine cold spring leakage bubbles.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0006] The present invention provides an in-situ image acquisition device for submarine cold spring seepage bubbles, comprising: a first pressure-resistant chamber, a visible light source, a first convex lens, a first window, a sampling column, a second pressure-resistant chamber, a second window, a second convex lens and a light field camera;

[0007] A first viewing window is arranged on any end surface of the first pressure-resistant chamber, the visible light source and the first convex lens are arranged inside the first pressure-resistant chamber, and the emission end of the visible light source, the optical center of the first convex lens and the center point of the first viewing window are coaxially arranged in sequence;

[0008] A second viewing window is arranged on any end surface of the second pressure-resistant chamber, the light field camera and the second convex lens are arranged inside the second pressure-resistant chamber, and the receiving end of the light field camera, the optical center of the second convex lens and the center point of the second viewing window are coaxially arranged in sequence;

[0009] One end of the sampling column is fixedly connected to the first window, and the other end of the sampling column is fixedly connected to the second window. The sampling column is provided with a through channel of equal diameter along the radial direction.

[0010] Preferably, the first pressure-resistant chamber and the second pressure-resistant chamber are both made of titanium alloy.

[0011] Preferably, the first window and the second window are both sapphire windows.

[0012] Preferably, the diameters of the first window, the second window and the sampling column are equal.

[0013] The present invention also provides an in-situ image acquisition method for submarine cold spring seepage bubbles, which is applied to the above-mentioned in-situ image acquisition device for submarine cold spring seepage bubbles, comprising:

[0014] S101: using an ROV to transport the in-situ image acquisition device for submarine cold seepage bubbles to a deep-sea cold seepage area for deployment, placing the equal-diameter channel of the sampling column above a selected target nozzle, and allowing the leakage bubbles to migrate in the equal-diameter channel of the sampling column;

[0015] S102: After a first preset time, the visible light source is controlled to emit light, which is refracted into parallel light by the first convex lens, and sequentially passes through the first window, the sampling column, and the second window to reach the second convex lens; the parallel light is focused by the second convex lens and then transmitted to the light field camera;

[0016] S103: The light field camera photographs the leakage bubbles in the equal-diameter channel according to a preset shooting interval time to obtain a plurality of original pictures of the leakage bubbles.

[0017] It should be noted that the first pressure-resistant chamber and the second pressure-resistant chamber are both titanium alloy rectangular parallelepiped structures with hollow cylindrical structures inside; the first window and the second window are both round sapphire windows; the sampling column is a cylinder, and the two ends are fixedly connected to the first window and the second window respectively; the diameter of the sampling column is equal to the diameter of the first window and the second window. The sampling column is provided with a through equal-diameter channel along the radial direction, and the diameter and volume of the equal-diameter channel are known, which is used as the migration scene of the leakage bubble. The in-situ image acquisition device for the leakage bubble of the seabed cold spring is carried on the ROV, transported to the deep-sea cold spring leakage area for arrangement, and the equal-diameter channel of the sampling column is arranged above the selected target nozzle, while avoiding the pressure-resistant chamber and the sampling column blocking the migration process of the leakage bubble at the target nozzle, resulting in the deviation of the in-situ leakage process of the seabed. After the sediment disturbance settlement caused by the in-situ image acquisition device for the leakage bubble of the seabed cold spring is stable, it can be seen that the light source emits light, which is refracted into parallel light by the first convex lens, and irradiated into the sampling column through the first window, completely covering the equal-diameter channel, and providing a stable light source. The leaking bubble migrates in the equal-diameter channel. After the parallel light hits the leaking bubble in the equal-diameter channel, the intensity generates difference information, which then passes through the second window to reach the second convex lens and is received by the light field camera after focusing. The light field camera is a device with a microlens array and an image sensor. After entering the microlens array of the light field camera, light with different incident angles is captured, and the image sensor generates image information with incident angle and intensity information, and records the shooting time of the image, forming an original picture of the leaking bubble with depth, viewing angle, light, and time information. The leaking bubble is continuously photographed in real time at a preset shooting interval to obtain several original pictures of the leaking bubble.

[0018] The present invention also provides a method for monitoring bubbles leaking from submarine cold springs, comprising:

[0019] S201: Based on the above-mentioned in-situ image acquisition method for submarine cold seepage bubbles, a plurality of original images of the leakage bubbles are obtained;

[0020] S202: using a light field image reconstruction algorithm to obtain a leakage bubble reconstructed image corresponding to each leakage bubble original image;

[0021] S203: using a boundary recognition algorithm to identify leakage bubbles from each of the leakage bubble reconstructed images, and calculating the centroid position and equivalent diameter of each leakage bubble;

[0022] S204: calculating the migration distance and migration rate of the leakage bubble based on the centroid positions of the corresponding leakage bubbles in different leakage bubble reconstructed images;

[0023] S205: Determine the newly entered leakage bubble and its volume from the different leakage bubble reconstructed images, and calculate the volume flux of the leakage bubble of the target nozzle.

[0024] Preferably, a light field image reconstruction algorithm is used to obtain a leakage bubble reconstructed image corresponding to each leakage bubble original image, including:

[0025] For each original image of the leakage bubble, project it onto a refocusing plane at different depths to obtain a plurality of refocusing images, and integrate the plurality of refocusing images to obtain a reconstructed image of the leakage bubble;

[0026] The calculation formula of the refocused image is:

[0027]

[0028] Where, I(x',y') represents the refocused image, a represents the refocusing coefficient, u and v represent the horizontal and vertical coordinates of the leakage bubble on the microlens array plane of the light field camera, and x' and y' represent the horizontal and vertical coordinates of the leakage bubble on the refocused image;

[0029] By adjusting the refocusing coefficient a, several refocusing images are obtained.

[0030] Preferably, calculating the center of mass position and equivalent diameter of each leakage bubble includes:

[0031] For each leakage bubble identified in the leakage bubble reconstructed image, the projection area of ​​the leakage bubble is calculated according to the number of pixels covered by the leakage bubble in the leakage bubble reconstructed image and the area of ​​a single pixel, and the equivalent diameter of the leakage bubble is calculated based on the projection area. The calculation formula is:

[0032]

[0033] Where, d e represents the equivalent diameter of the leakage bubble, and A represents the projected area of ​​the leakage bubble;

[0034] Based on the number of pixels covered by the leakage bubble in the leakage bubble reconstructed image and the sum of the ordinates of all covered pixels, the centroid position of the leakage bubble is calculated using the following formula:

[0035]

[0036] In the formula, The vertical coordinate of the centroid of the leakage bubble in the reconstructed image of the leakage bubble at time ti, y i represents the vertical coordinate of the pixels covered by the leakage bubble, and N represents the number of pixels covered by the leakage bubble.

[0037] Preferably, the migration distance and migration rate of the leakage bubble are calculated based on the centroid positions of the corresponding leakage bubbles in different leakage bubble reconstructed images, including:

[0038] The calculation formula of the migration distance of the leakage bubble is:

[0039]

[0040] Where Δh represents the migration distance of the seepage bubble. A positive value indicates migration toward the water surface, and a negative value indicates migration toward the sediment. represents the centroid ordinate of the leakage bubble in the reconstructed image of the leakage bubble at time tj, represents the vertical coordinate of the centroid of the leakage bubble in the reconstructed image of the leakage bubble at time ti, j>ti;

[0041] The calculation formula of the migration rate of leakage bubbles is:

[0042]

[0043] Where v represents the migration rate of the leakage bubble.

[0044] Preferably, calculating the volume flux of the target nozzle leakage bubble includes:

[0045]

[0046] In the formula, R v represents the volume flux of leakage bubbles from the target nozzle, V represents the total volume of newly entered leakage bubbles in different leakage bubble reconstruction images, S represents the bottom area of ​​the equal-diameter channel of the sampling column, and Δt represents the time interval between different leakage bubble reconstruction images.

[0047] It should be noted that after obtaining several original images of leakage bubbles in time series, the light field image reconstruction algorithm is used to obtain the leakage bubble reconstructed image corresponding to each leakage bubble original image, and the thinking information of three-dimensional space plus time dimension is formed by combining the time scale. The leakage bubble is identified by the boundary recognition algorithm, and the center of mass position and equivalent diameter of the leakage bubble are calculated. According to the center of mass position and equivalent diameter of the leakage bubble, the shape and size of each leakage bubble can be obtained, and the size distribution can be statistically calculated; the change of the center of mass position of the same leakage bubble in two leakage bubble reconstructed images can calculate the migration distance of the leakage bubble, and the migration rate of the leakage bubble can be calculated by combining the shooting interval time of the two leakage bubble reconstructed images. By comparing the two leakage bubble reconstructed images, the newly entered leakage bubble and its volume are identified, and the volume flux of the leakage bubble can be calculated by combining the bottom area of ​​the equal-diameter channel and the shooting interval time of the two leakage bubble reconstructed images. Finally, the size, shape, migration rate, volume flux, and size distribution of the submarine cold spring leakage bubble are obtained.

[0048] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0049] The in-situ image acquisition device for submarine cold spring seepage bubbles provided by the present invention includes a first window arranged on any end face of a first pressure-resistant chamber, a visible light source and a first convex lens arranged inside the first pressure-resistant chamber; a second window arranged on any end face of a second pressure-resistant chamber, a light field camera and a second convex lens arranged inside the second pressure-resistant chamber; two ends of a sampling column are respectively fixedly connected to the first window and the second window, and the sampling column is provided with a through equal-diameter channel in the radial direction. When collecting images, the in-situ image acquisition device for submarine cold spring seepage bubbles is carried on an ROV, transported to a deep-sea cold spring seepage area for arrangement, the equal-diameter channel of the sampling column is arranged above the selected target nozzle, the visible light source is controlled to emit light, which is refracted into parallel light by the first convex lens, and sequentially passes through the first window, the sampling column, and the second window to reach the second convex lens; after the parallel light is focused by the second convex lens, it is transmitted to the light field camera, and the light field camera takes pictures of the seepage bubbles in the equal-diameter channel according to the preset shooting interval time, and obtains several original pictures of the seepage bubbles. The method for monitoring submarine cold spring seepage bubbles provided by the present invention obtains the corresponding reconstructed image of the seepage bubbles based on the collected original image of the seepage bubbles by using the light field image reconstruction algorithm, and then identifies and calculates the fine parameters such as the centroid position, equivalent diameter, migration rate, and volume flux of the seepage bubbles. The present invention can be deployed in situ to accurately obtain the image of submarine cold spring seepage bubbles, and based on the obtained image of the seepage bubbles, the fine parameters of the seepage bubbles are monitored, thereby comprehensively, objectively, and accurately revealing the migration and transformation laws of submarine seepage methane bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a front view of an in-situ image acquisition device for submarine cold seepage bubbles described in Example 1;

[0051] Figure 2 A top view of an in-situ image acquisition device for submarine cold seepage bubbles described in Example 1;

[0052] Figure 3 This is a flow chart of an in-situ image acquisition method for submarine cold seepage bubbles described in Example 2;

[0053] Figure 4 This is a flow chart of a method for monitoring bubbles in submarine cold seepage as described in Example 3;

[0054] Figure 5 Schematic diagram of the principle of obtaining leakage bubble reconstruction image described in Example 3. DETAILED DESCRIPTION

[0055] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0056] In order to better illustrate the present embodiment, some parts in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product;

[0057] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0058] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0059] Example 1

[0060] This embodiment provides an in-situ image acquisition device for bubbles leaking from cold springs on the seafloor. Figure 1 and 2 As shown, it includes: a first pressure-resistant chamber 1, a visible light source 2, a first convex lens 3, a first window 4, a sampling column 5, a second pressure-resistant chamber 6, a second window 7, a second convex lens 8 and a light field camera 9;

[0061] A first viewing window 4 is provided on any end surface of the first pressure-resistant chamber 1, the visible light source 2 and the first convex lens 3 are provided inside the first pressure-resistant chamber 1, and the emission end of the visible light source 2, the optical center of the first convex lens 3 and the center point of the first viewing window 4 are coaxially arranged in sequence;

[0062] A second viewing window 7 is provided on any end surface of the second pressure-resistant chamber 6, the light field camera 9 and the second convex lens 8 are arranged inside the second pressure-resistant chamber 6, and the receiving end of the light field camera 9, the optical center of the second convex lens 8 and the center point of the second viewing window 7 are coaxially arranged in sequence;

[0063] One end of the sampling column 5 is fixedly connected to the first viewing window 4 , and the other end of the sampling column 5 is fixedly connected to the second viewing window 7 . The sampling column 5 is provided with a through channel 10 of equal diameter in the radial direction.

[0064] In this embodiment, the materials of the first pressure-resistant chamber 1 and the second pressure-resistant chamber 6 are both titanium alloy, the first window 4 and the second window 7 are both sapphire windows, and the diameters of the first window 4, the second window 7 and the sampling column 5 are equal.

[0065] In the specific implementation process, the first pressure-resistant chamber and the second pressure-resistant chamber are both titanium alloy rectangular parallelepiped structures with hollow cylindrical structures inside; the first window and the second window are both round sapphire windows; the sampling column is a cylinder, and the two ends are fixedly connected to the first window and the second window respectively; the diameter of the sampling column is equal to the diameter of the first window and the second window. The sampling column is provided with a through equal-diameter channel along the radial direction, and the diameter and volume of the equal-diameter channel are known, which is used as the migration scene of the leakage bubble. The in-situ image acquisition device for the leakage bubble of the seabed cold spring is carried on the ROV, transported to the deep-sea cold spring leakage area for arrangement, and the equal-diameter channel of the sampling column is arranged above the selected target nozzle, while avoiding the pressure-resistant chamber and the sampling column blocking the migration process of the leakage bubble at the target nozzle, resulting in the deviation of the in-situ leakage process of the seabed. After the sediment disturbance settlement caused by the in-situ image acquisition device for the leakage bubble of the seabed cold spring is stable, it can be seen that the light source emits light, which is refracted into parallel light by the first convex lens, and irradiated into the sampling column through the first window, completely covering the equal-diameter channel, and providing a stable light source. The leaking bubble migrates in the equal-diameter channel. After the parallel light hits the leaking bubble in the equal-diameter channel, the intensity generates difference information, which then passes through the second window to reach the second convex lens and is received by the light field camera after focusing. The light field camera is a device with a microlens array and an image sensor. After entering the microlens array of the light field camera, light with different incident angles is captured, and the image sensor generates image information with incident angle and intensity information, and records the shooting time of the image, forming an original picture of the leaking bubble with depth, viewing angle, light, and time information. The leaking bubble is continuously photographed in real time at a preset shooting interval to obtain several original pictures of the leaking bubble.

[0066] Example 2

[0067] This embodiment provides an in-situ image acquisition method for submarine cold spring leakage bubbles, which is applied to the in-situ image acquisition device for submarine cold spring leakage bubbles described in Example 1. Figure 3 As shown, including:

[0068] S101: using an ROV to transport the in-situ image acquisition device for submarine cold seepage bubbles to a deep-sea cold seepage area for deployment, placing the equal-diameter channel of the sampling column above a selected target nozzle, and allowing the leakage bubbles to migrate in the equal-diameter channel of the sampling column;

[0069] S102: After a first preset time, the visible light source is controlled to emit light, which is refracted into parallel light by the first convex lens, and sequentially passes through the first window, the sampling column, and the second window to reach the second convex lens; the parallel light is focused by the second convex lens and then transmitted to the light field camera;

[0070] S103: The light field camera photographs the leakage bubbles in the equal-diameter channel according to a preset shooting interval time to obtain a plurality of original pictures of the leakage bubbles.

[0071] It can be understood that a light field camera is a device with a microlens array and an image sensor. After the light enters the microlens array of the light field camera, the light at different incident angles is captured, and the image sensor generates image information with incident angle and intensity information. The image processing algorithm can analyze and construct the scene depth, viewing angle, light and other information in the image information to construct a stereoscopic image and a time series of the motion process.

[0072] In actual use, the in-situ image acquisition device for submarine cold spring seepage bubbles is mounted on an ROV and transported to a deep-sea cold spring seepage area for deployment. The equal-diameter channel of the sampling column is arranged above the selected target nozzle, and at the same time, the pressure-resistant cabin and the sampling column are prevented from blocking the migration process of the leakage bubbles at the target nozzle, causing the in-situ leakage process of the seabed to deviate. After the sediment disturbance and sedimentation caused by the in-situ image acquisition device for submarine cold spring seepage bubbles are stabilized, the visible light source emits light, which is refracted into parallel light by the first convex lens, and irradiated into the sampling column through the first window, completely covering the equal-diameter channel, and providing a stable light source. The leakage bubble migrates in the equal-diameter channel, and the parallel light irradiates the leakage bubble in the equal-diameter channel to produce difference information in intensity, and then reaches the second convex lens through the second window, and is received by the light field camera after focusing. A light field camera is a device with a microlens array and an image sensor. Light of different incident angles is captured after entering the microlens array of the light field camera, and the image sensor generates image information with incident angle and intensity information, and records the shooting time of the image, forming an original picture of the leaking bubble with depth, viewing angle, light, and time information. The leaking bubble is continuously photographed in real time at a preset shooting interval to obtain several original pictures of the leaking bubble.

[0073] Example 3

[0074] This embodiment provides a method for monitoring bubbles in submarine cold springs. Figure 4 As shown, including:

[0075] S201: Based on the in-situ image acquisition method for submarine cold seepage bubbles described in Example 2, a plurality of original images of leakage bubbles are acquired;

[0076] S202: using a light field image reconstruction algorithm to obtain a leakage bubble reconstructed image corresponding to each leakage bubble original image;

[0077] S203: using a boundary recognition algorithm to identify leakage bubbles from each of the leakage bubble reconstructed images, and calculating the centroid position and equivalent diameter of each leakage bubble;

[0078] S204: calculating the migration distance and migration rate of the leakage bubble based on the centroid positions of the corresponding leakage bubbles in different leakage bubble reconstructed images;

[0079] S205: Determine the newly entered leakage bubble and its volume from the different leakage bubble reconstructed images, and calculate the volume flux of the leakage bubble of the target nozzle.

[0080] It should be noted that the light field theory was proposed by Alexander Gershun in 1936 to explain the three-dimensional process of light propagation. In 1991, Edward H. Adelson and James R. Bergen recorded the three-dimensional propagation process of light through the seven-dimensional plenoptic function L (θ, φ, λ, t, X, Y, Z), where θ and φ represent the direction of the light, λ represents the wavelength of the light, t represents time, and X, Y, Z represent the three-dimensional coordinates of the target point on the light path. On this basis, Michael Landy and J. Anthony Movshon proposed the light field dual-plane (u, v, x, y) model, where (u, v) represents the angular resolution and (x, y) represents the imaging plane, that is, the intersection formed when the light passes through two known planes (u, v) and (x, y). The light field camera is equipped with a microlens array and an image sensor. The microlens array is set as plane UV, and the image sensor is set as plane XY (x, y). The distance between the two planes is known and set to d. The light refracts through the microlens array and enters the image sensor. The intersection of plane UV is (u, v), and the intersection of plane XY is (x, y). Therefore, the (u, v, x, y) function can be used to indicate the propagation direction of the surface light. The pixel grayscale of the intersection can represent the intensity I of the light, that is, I = L (u, v, x, y). Based on the above theory:

[0081] Using the light field image reconstruction algorithm, the reconstructed image of the leakage bubble corresponding to each original image of the leakage bubble is obtained, including:

[0082] like Figure 5 As shown, for each original image of the leakage bubble, it is projected onto the refocusing plane at different depth positions to obtain a plurality of refocusing images, and the plurality of refocusing images are integrated to obtain a reconstructed image of the leakage bubble;

[0083] The calculation formula of the refocused image is:

[0084]

[0085] Where, I(x',y') represents the refocused image, a represents the refocusing coefficient, u and v represent the horizontal and vertical coordinates of the leakage bubble on the microlens array plane of the light field camera, and x' and y' represent the horizontal and vertical coordinates of the leakage bubble on the refocused image;

[0086] By adjusting the refocusing coefficient a, several refocusing images are obtained.

[0087] Calculate the center of mass position and equivalent diameter of each leakage bubble, including:

[0088] For each leakage bubble identified in the leakage bubble reconstructed image, the projection area of ​​the leakage bubble is calculated according to the number of pixels covered by the leakage bubble in the leakage bubble reconstructed image and the area of ​​a single pixel, and the equivalent diameter of the leakage bubble is calculated based on the projection area. The calculation formula is:

[0089]

[0090] Where, d e represents the equivalent diameter of the leakage bubble, and A represents the projected area of ​​the leakage bubble;

[0091] Based on the number of pixels covered by the leakage bubble in the leakage bubble reconstructed image and the sum of the ordinates of all covered pixels, the centroid position of the leakage bubble is calculated using the following formula:

[0092]

[0093] In the formula, The vertical coordinate of the centroid of the leakage bubble in the reconstructed image of the leakage bubble at time ti, y i represents the vertical coordinate of the pixels covered by the leakage bubble, and N represents the number of pixels covered by the leakage bubble.

[0094] Based on the centroid positions of the corresponding leakage bubbles in different leakage bubble reconstructed images, the migration distance and migration rate of the leakage bubbles are calculated, including:

[0095] The calculation formula of the migration distance of the leakage bubble is:

[0096]

[0097] Where Δh represents the migration distance of the seepage bubble. A positive value indicates migration toward the water surface, and a negative value indicates migration toward the sediment. represents the centroid ordinate of the leakage bubble in the reconstructed image of the leakage bubble at time tj, Represents the centroid ordinate of the leakage bubble in the reconstructed image of the leakage bubble at time ti, tj>ti;

[0098] The calculation formula of the migration rate of leakage bubbles is:

[0099]

[0100] Where v represents the migration rate of the leakage bubble.

[0101] Calculate the volume flux of the target nozzle leakage bubble, including:

[0102]

[0103] In the formula, R v represents the volume flux of leakage bubbles from the target nozzle, V represents the total volume of newly entered leakage bubbles in different leakage bubble reconstruction images, S represents the bottom area of ​​the equal-diameter channel of the sampling column, and Δt represents the time interval between different leakage bubble reconstruction images.

[0104] It should be noted that after obtaining several original images of leakage bubbles in time series, the light field image reconstruction algorithm is used to obtain the leakage bubble reconstructed image corresponding to each leakage bubble original image, and the thinking information of three-dimensional space plus time dimension is formed by combining the time scale. The leakage bubble is identified by the boundary recognition algorithm, and the center of mass position and equivalent diameter of the leakage bubble are calculated. According to the center of mass position and equivalent diameter of the leakage bubble, the shape and size of each leakage bubble can be obtained, and the size distribution can be statistically calculated; the change of the center of mass position of the same leakage bubble in two leakage bubble reconstructed images can calculate the migration distance of the leakage bubble, and the migration rate of the leakage bubble can be calculated by combining the shooting interval time of the two leakage bubble reconstructed images. By comparing the two leakage bubble reconstructed images, the newly entered leakage bubble and its volume are identified, and the volume flux of the leakage bubble can be calculated by combining the bottom area of ​​the equal-diameter channel and the shooting interval time of the two leakage bubble reconstructed images. Finally, the size, shape, migration rate, volume flux, and size distribution of the submarine cold spring leakage bubble are obtained.

[0105] The same or similar reference numerals correspond to the same or similar components;

[0106] The terms used in the drawings to describe positional relationships are only used for illustrative purposes and should not be construed as limiting this patent;

[0107] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An in-situ image acquisition device for bubbles leaking from submarine cold springs, characterized in that: include: A first pressure-resistant chamber (1), a visible light source (2), a first convex lens (3), a first viewing window (4), a sampling column (5), a second pressure-resistant chamber (6), a second viewing window (7), a second convex lens (8) and a light field camera (9); A first viewing window (4) is arranged on any end surface of the first pressure-resistant chamber (1), the visible light source (2) and the first convex lens (3) are arranged inside the first pressure-resistant chamber (1), and the emission end of the visible light source (2), the optical center of the first convex lens (3) and the center point of the first viewing window (4) are coaxially arranged in sequence; A second viewing window (7) is arranged on any end surface of the second pressure-resistant chamber (6), the light field camera (9) and the second convex lens (8) are arranged inside the second pressure-resistant chamber (6), and the receiving end of the light field camera (9), the optical center of the second convex lens (8) and the center point of the second viewing window (7) are coaxially arranged in sequence; One end of the sampling column (5) is fixedly connected to the first window (4), and the other end of the sampling column (5) is fixedly connected to the second window (7). The sampling column (5) is provided with a through-going equal-diameter channel (10) along the radial direction.

2. The in-situ image acquisition device for submarine cold seepage bubbles according to claim 1 is characterized in that: The first pressure-resistant chamber (1) and the second pressure-resistant chamber (6) are both made of titanium alloy.

3. The in-situ image acquisition device for submarine cold seepage bubbles according to claim 1 is characterized in that: The first window (4) and the second window (7) are both sapphire windows.

4. The in-situ image acquisition device for submarine cold seepage bubbles according to claim 1 is characterized in that: The diameters of the first viewing window (4), the second viewing window (7) and the sampling column (5) are equal.

5. An in-situ image acquisition method for submarine cold spring seepage bubbles, applied to the in-situ image acquisition device for submarine cold spring seepage bubbles described in claims 1-4, characterized in that: include: S101: using an ROV to transport the in-situ image acquisition device for submarine cold seepage bubbles to a deep-sea cold seepage area for deployment, placing the equal-diameter channel of the sampling column above a selected target nozzle, and allowing the leakage bubbles to migrate in the equal-diameter channel of the sampling column; S102: After a first preset time, the visible light source is controlled to emit light, which is refracted into parallel light by the first convex lens, and sequentially passes through the first window, the sampling column, and the second window to reach the second convex lens; the parallel light is focused by the second convex lens and then transmitted to the light field camera; S103: The light field camera photographs the leakage bubbles in the equal-diameter channel according to a preset shooting interval time to obtain a plurality of original pictures of the leakage bubbles.

6. A method for monitoring bubbles leaking from submarine cold springs, characterized in that: include: S201: Based on the in-situ image acquisition method for submarine cold seepage bubbles described in claim 5, a plurality of original images of the leakage bubbles are obtained; S202: using a light field image reconstruction algorithm to obtain a leakage bubble reconstructed image corresponding to each leakage bubble original image; S203: using a boundary recognition algorithm to identify leakage bubbles from each of the leakage bubble reconstructed images, and calculating the centroid position and equivalent diameter of each leakage bubble; S204: calculating the migration distance and migration rate of the leakage bubble based on the centroid positions of the corresponding leakage bubbles in different leakage bubble reconstructed images; S205: Determine the newly entered leakage bubble and its volume from the different leakage bubble reconstructed images, and calculate the volume flux of the leakage bubble of the target nozzle.

7. The method for monitoring bubbles of submarine cold seepage according to claim 6, characterized in that: Using the light field image reconstruction algorithm, the reconstructed image of the leakage bubble corresponding to each original image of the leakage bubble is obtained, including: For each original image of the leakage bubble, project it onto a refocusing plane at different depths to obtain a plurality of refocusing images, and integrate the plurality of refocusing images to obtain a reconstructed image of the leakage bubble; The calculation formula of the refocused image is: Where, I(x',y') represents the refocused image, a represents the refocusing coefficient, u and v represent the horizontal and vertical coordinates of the leakage bubble on the microlens array plane of the light field camera, and x' and y' represent the horizontal and vertical coordinates of the leakage bubble on the refocused image; By adjusting the refocusing coefficient a, several refocusing images are obtained.

8. The method for monitoring bubbles of submarine cold seepage according to claim 6, characterized in that: Calculate the center of mass position and equivalent diameter of each leakage bubble, including: For each leakage bubble identified in the leakage bubble reconstructed image, the projection area of ​​the leakage bubble is calculated according to the number of pixels covered by the leakage bubble in the leakage bubble reconstructed image and the area of ​​a single pixel, and the equivalent diameter of the leakage bubble is calculated based on the projection area. The calculation formula is: Where, d e represents the equivalent diameter of the leakage bubble, and A represents the projected area of ​​the leakage bubble; Based on the number of pixels covered by the leakage bubble in the leakage bubble reconstructed image and the sum of the ordinates of all covered pixels, the centroid position of the leakage bubble is calculated using the following formula: In the formula, The vertical coordinate of the centroid of the leakage bubble in the reconstructed image of the leakage bubble at time ti, y i represents the vertical coordinate of the pixels covered by the leakage bubble, and N represents the number of pixels covered by the leakage bubble.

9. The method for monitoring bubbles of submarine cold seepage according to claim 8, characterized in that: Based on the centroid positions of the corresponding leakage bubbles in different leakage bubble reconstructed images, the migration distance and migration rate of the leakage bubbles are calculated, including: The calculation formula of the migration distance of the leakage bubble is: Where Δh represents the migration distance of the seepage bubble. A positive value indicates migration toward the water surface, and a negative value indicates migration toward the sediment. represents the centroid ordinate of the leakage bubble in the reconstructed image of the leakage bubble at time tj, Represents the centroid ordinate of the leakage bubble in the reconstructed image of the leakage bubble at time ti, tj>ti; The calculation formula of the migration rate of leakage bubbles is: Where v represents the migration rate of the leakage bubble.

10. The method for monitoring bubbles of submarine cold seepage according to claim 8, characterized in that: Calculate the volume flux of the target nozzle leakage bubble, including: In the formula, R v represents the volume flux of leakage bubbles from the target nozzle, V represents the total volume of newly entered leakage bubbles in different leakage bubble reconstruction images, S represents the bottom area of ​​the equal-diameter channel of the sampling column, and Δt represents the time interval between different leakage bubble reconstruction images.

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