Ship navigation situation awareness system and display optimization method thereof

Abstract

The invention relates to the field of ship navigation, in particular to a ship navigation situation awareness system and a display optimization method thereof, the display optimization method comprises three-dimensional engine function disassembly and replacement and display frame rate adaptive optimization, the three-dimensional engine function disassembly and replacement comprises a two-dimensional coordinate conversion module and a three-dimensional coordinate conversion module, and the three-dimensional coordinate conversion module comprises a three-dimensional coordinate conversion module. The information drawing module and the video stream processing display module are superposed, and the self-adaptive optimization of the display frame rate is realized by setting a plurality of display strategies, so that the pressure of computer graph drawing is reduced. A three-dimensional engine function is divided into two-dimensional and three-dimensional coordinate conversion, superposition information drawing and video stream processing display, replacement is carried out through corresponding function modules, the three-dimensional engine is finally replaced, meanwhile, by setting a stepped display strategy, self-adaptive optimization of the display frame rate is achieved, and the display efficiency is improved. Finally, the display effect of the ship navigation situation awareness system on a domestic platform is similar to that on a non-domestic hardware platform, and the user experience is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of ship navigation, and in particular to a ship navigation situation awareness system and a display optimization method thereof. Background Art

[0002] With the trend of domestic ships and domestic equipment, domestic computing platforms are gradually uploaded and deployed. The display end of the ship navigation situation awareness system is developed based on a three-dimensional engine. When it is migrated to domestic equipment, there are problems such as lag and poor software compatibility, which cannot meet the needs of application scenarios.

[0003] The display of the ship navigation situation awareness system based on the 3D engine requires a series of processes such as modeling, mapping, and rendering, which consumes a lot of computing and drawing resources. When the domestic computing platform displays the navigation situation, the hardware performance is insufficient, resulting in display lag and extremely low frame rate. In order to achieve good results in the display of the ship navigation situation awareness system on the domestic platform, it is necessary to disassemble, replace and optimize the application functions of the current 3D engine, reduce redundant resource consumption, and perform dynamic display optimization. Summary of the invention

[0004] In order to overcome the problem of insufficient performance and poor adaptation effect of domestic chips and domestic graphics cards, the present invention provides a display optimization method based on a ship navigation situation awareness system. The optimization algorithm of the present invention increases the smoothness of displaying background video streams and operations of the ship navigation situation awareness system through disassembly and replacement, meeting the requirements of application scenarios.

[0005] On the one hand, the present invention provides a display optimization method based on a ship navigation situation awareness system, which adopts the following technical solutions:

[0006] A display optimization method based on a ship navigation situation awareness system, the display optimization method comprising a three-dimensional engine function disassembly and replacement link and a display frame rate adaptive optimization link, in the three-dimensional engine function disassembly link:

[0007] S1. The 3D engine function is decomposed into 2D and 3D coordinate conversion, video stream background overlay display and overlay information drawing. The 3D engine obtains longitude and latitude coordinates by modeling the earth, and establishes a world coordinate system based on them;

[0008] S2. 2D and 3D coordinate conversion: establish a camera coordinate system according to the camera position and posture information, convert the world coordinates to the camera coordinates based on the camera coordinate system, set up a virtual field, use the algorithm to achieve the conversion of the 2D and 3D coordinate systems, establish a projection coordinate system through the camera's horizontal / vertical field of view and focal length and other parameters, convert the camera coordinates to projection coordinates, i.e. 2D screen coordinates, the longitude and latitude coordinates to 2D screen coordinates are used for superimposed information position display and superimposed information drawing, and the 2D screen coordinates are converted to longitude and latitude coordinates for distance measurement, position measurement and target fusion;

[0009] S3. Drawing of superimposed information, calculating the boundaries of various superimposed elements through the two-dimensional and three-dimensional coordinate conversion, and drawing various superimposed elements, the superimposed elements include fixed object elements, custom superimposed elements and complex superimposed elements with unknown information;

[0010] S4. Video stream processing and display, optimize video stream processing and display, and improve video stream display frame rate;

[0011] In the display frame rate adaptive optimization link:

[0012] S5. The display frame rate adaptive optimization is achieved by setting a variety of display strategies to reduce the pressure of computer graphics rendering.

[0013] In S2, the two-dimensional and three-dimensional coordinate transformation specifically includes the following transformation steps:

[0014] S21. Establish a camera coordinate system based on the position and posture information of the camera;

[0015] S22. Convert the longitude and latitude coordinates into world coordinates by calculation;

[0016] S23. Converting the world coordinates to the camera coordinates based on the camera coordinate system;

[0017] S24. Establishing a projection coordinate system through the camera's horizontal / vertical field of view angle and focal length and other parameters;

[0018] S25. Convert the camera coordinates into projection coordinates, that is, two-dimensional screen coordinates.

[0019] The two-dimensional and three-dimensional coordinate conversion also includes the following conversion steps:

[0020] S26. Convert the two-dimensional coordinates into camera coordinates through the projection coordinate system;

[0021] S27. Convert the camera coordinates into world coordinates through the camera coordinate system;

[0022] S28. Convert the world coordinates into longitude and latitude coordinates by longitude and latitude calculation.

[0023] In S3, the fixed object marker elements are specifically drawn in a manner of preprocessing the fixed object marker elements, simplifying the number of displayed faces and complexity, saving the presets, and calling and drawing them during operation.

[0024] In S3, the custom overlay element is drawn in a specific manner of converting the latitude and longitude points of the boundary points / key points of the custom overlay element into screen coordinate points to form boundary / key screen coordinate points (sets), and drawing the custom overlay element using a polygon drawing algorithm.

[0025] In S3, drawing the unknown information complex overlay element includes the following steps:

[0026] S31. Output the selection result through the server;

[0027] S32. Obtain the color distribution in the frame selection result image, and remove the background part by color;

[0028] S33. grayscale processing is performed on the image after background removal to extract contour lines;

[0029] S34. Convert the contour line from relative coordinates to screen absolute coordinates;

[0030] S35. Obtain all contour lines for overlay drawing.

[0031] In S4, the video stream processing and display includes a stream pulling thread and a processing thread. The stream pulling thread is used to pull the video stream in real time and cache the acquired image frames. The processing thread obtains the latest image frame in the cache, performs distortion correction, and transmits the image to the server, and displays the real-time image frame as the software background.

[0032] Furthermore, the pulling process triggers the task of pulling the video stream periodically, and the time interval for executing the task of pulling the video stream once is fixed, and the time interval is set according to the frame rate of the video stream. The execution interval of the processing thread task is adaptively adjusted according to the real-time frame rate displayed by the software.

[0033] In S5, the adaptive optimization of the display strategy is specifically to adjust the configuration items, and the configuration items include:

[0034] S51. Adjust the frequency of drawing the fixed object elements and the recognition results and the frequency of transmitting them to the image recognition server;

[0035] S52. Adjust the contour recognition frequency of distant objects and the contour recognition frequency of nearby objects;

[0036] S53. Adjust the drawing frequency of custom overlay elements.

[0037] On the other hand, the present invention also provides a ship navigation situation awareness system, including a camera and a display control computer, wherein the display control computer is provided with a two-dimensional and three-dimensional coordinate conversion module, an overlay information drawing module and a video stream display module, wherein:

[0038] The two-dimensional and three-dimensional coordinate conversion module establishes a camera coordinate system according to the camera position and posture information, converts the world coordinates into the camera coordinates based on the camera coordinate system, sets up a virtual field, uses an algorithm to achieve the conversion of the two-dimensional and three-dimensional coordinate systems, establishes a projection coordinate system through the camera's horizontal / vertical field of view and focal length and other parameters, converts the camera coordinates into projection coordinates, i.e., two-dimensional screen coordinates, and converts the longitude and latitude coordinates into two-dimensional screen coordinates for displaying the superimposed information position and drawing the superimposed information, and converts the two-dimensional screen coordinates into longitude and latitude coordinates for distance measurement, position measurement and target fusion;

[0039] A superimposed information drawing module calculates the boundaries of various superimposed elements through the two-dimensional and three-dimensional coordinate conversion module, and draws various superimposed elements, wherein the superimposed elements include fixed object mark elements, user-defined superimposed elements, and complex superimposed elements with unknown information;

[0040] The video stream display module processes and displays the video stream and improves the video stream display frame rate by optimizing the video stream processing and display;

[0041] A stepped display strategy algorithm is embedded to achieve adaptive optimization of display frame rate, specifically by adjusting configuration items to reduce the pressure of computer graphics rendering.

[0042] In summary, the present invention includes at least one of the following beneficial technical effects:

[0043] 1. The present invention replaces the 3D engine by disassembling the functions of the 3D engine and performing replacements respectively. While ensuring the functional integrity, the 3D engine that occupies a large number of resources is stripped off, thereby improving the display effect on the domestic hardware platform;

[0044] 2. The present invention realizes adaptive optimization of display frame rate by embedding a stepped display strategy algorithm, specifically adjusting the configuration items to reduce the pressure of computer graphics rendering. After functional replacement, the display effect of the ship navigation situation awareness system is similar to the display effect of using a three-dimensional engine on a non-domestic hardware platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the display optimization process of an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0047] The display of the ship navigation situation awareness system based on the 3D engine requires a series of processes such as modeling, mapping, and rendering, which consumes a lot of computing and drawing resources. When the navigation situation is displayed on the domestic computing platform, the hardware performance is insufficient, resulting in display jams and extremely low frame rates. In order to achieve good results in the display of the ship navigation situation awareness system on the domestic platform, it is necessary to disassemble, replace and optimize the application functions of the current 3D engine, reduce redundant resource consumption, and perform dynamic display optimization.

[0048] Example 1

[0049] Embodiment 1 of the present invention discloses a display optimization method based on a ship navigation situation awareness system. By disassembling and replacing the functions of a three-dimensional engine, the smoothness of displaying background video streams and operations of the ship navigation situation awareness system is increased to meet the use requirements of application scenarios.

[0050] The 3D engine mainly builds the world coordinate system by modeling the earth, then sets the virtual camera according to the ship's posture and position information, builds a 2D and 3D mapping relationship, and realizes 2D and 3D coordinate conversion. Then, the video stream information is mapped on the preset model, and the second camera is used as the background camera to model the overlay information. Finally, the overlay information is superimposed on the video stream through overall rendering and the overall output is displayed.

[0051] Based on the functions realized by the above-mentioned three-dimensional engine in the actual ship navigation situation awareness system, its functions can be broken down into three modules: two- and three-dimensional coordinate conversion, overlay information drawing, and video stream background overlay display.

[0052] The display optimization method based on the ship navigation state perception system of the present invention includes two parts: three-dimensional engine function disassembly and replacement and display frame rate adaptive optimization. As mentioned above, the three-dimensional engine function disassembly and replacement includes a two-dimensional coordinate conversion module, an overlay information drawing module and a video stream processing and display module.

[0053] The two-dimensional and three-dimensional coordinate conversion module establishes a virtual field and uses existing algorithms to achieve two-dimensional and three-dimensional coordinate conversion; the overlay information drawing module calculates the boundaries of the measured graphics through two-dimensional and three-dimensional coordinate conversion and draws various overlay elements separately; the video stream processing and display module improves the video stream display frame rate by optimizing the video stream processing and display.

[0054] Specifically, the conversion of two-dimensional coordinates into three-dimensional coordinates includes two parts: the conversion of two-dimensional coordinates into three-dimensional coordinates and the conversion of three-dimensional coordinates into two-dimensional coordinates. The conversion of three-dimensional coordinates into two-dimensional coordinates includes the following steps:

[0055] Establish a camera coordinate system based on the camera's position and posture information;

[0056] Convert the longitude and latitude coordinates (i.e. three-dimensional coordinates) into world coordinates through calculation;

[0057] Convert world coordinates to camera coordinates based on the camera coordinate system;

[0058] Establish a projection coordinate system through the camera's horizontal / vertical field of view angle and focal length and other parameters;

[0059] The camera coordinates are converted into projection coordinates, that is, two-dimensional coordinates, based on the projection coordinate system.

[0060] The conversion of two-dimensional coordinates into three-dimensional coordinates includes the following steps:

[0061] Convert the two-dimensional coordinates into camera coordinates through the projection coordinate system;

[0062] Convert the camera coordinates into world coordinates through the camera coordinate system;

[0063] The world coordinates are converted into longitude and latitude coordinates, that is, three-dimensional coordinates, through longitude and latitude calculations.

[0064] The specific calculation and conversion between the above different coordinates are common knowledge and will not be elaborated here. In the 3D engine, the overlay information drawing is to draw the overlay elements on the basis of the video stream, superimpose them on the video stream, form a model entity, and then place them in a fixed position and adjust the posture, and finally render and output.

[0065] In order to reduce the performance burden, the present invention adopts a method of preprocessing and calculating boundary points through two-dimensional and three-dimensional coordinate conversion, and adopts different drawing strategies for different types of superimposed elements, which include fixed object mark elements, custom superimposed elements and complex superimposed elements with unknown information. Fixed object mark elements convert the geographical location of the object mark into two-dimensional screen coordinates through two-dimensional and three-dimensional coordinate conversion, and draw the preset graphics of the fixed object mark elements at the corresponding screen position after conversion. Custom superimposed elements convert the longitude and latitude of boundary points / key points into screen coordinate points through two-dimensional and three-dimensional coordinate conversion to form boundary / key screen coordinate points (sets), and draw this type of superimposed elements through polygon drawing algorithms. Complex superimposed elements with unknown information convert known geographical locations into two-dimensional screen coordinates through two-dimensional and three-dimensional conversion technology, preliminarily locate the position of this type of element on the screen, and perform target recognition on this basis to improve recognition efficiency.

[0066] Fixed object elements refer to superimposed elements with relatively fixed shapes, including buoys, lighthouses, etc. Fixed objects are preprocessed to simplify the number of faces and complexity of display and save as presets, which can be directly called and drawn during operation. Simplified display should be based on the ability to ensure the characteristics of fixed object elements.

[0067] The fixed object element converts the geographical location of the object into two-dimensional screen coordinates through two-dimensional and three-dimensional coordinate conversion, and draws the preset graphic of the fixed object element at the corresponding screen position after conversion.

[0068] Custom overlay elements include waterways, restricted areas, coastlines, sea-sky lines, distance rings and parallel lines. These overlay elements convert the longitude and latitude of boundary points / key points into screen coordinate points through two-dimensional and three-dimensional coordinate conversion to form boundary / key screen coordinate points (sets), and are drawn using a polygon drawing algorithm.

[0069] Unknown information complex overlay elements refer to elements with unknown or insufficient information, and their shapes are not completely fixed. For example, the type, size, angle and other parameters of the hull are unknown or not feasible, and difficult to determine by preset. For such overlay elements, it is necessary to use two-dimensional and three-dimensional coordinate conversion technology to convert the known geographical location into two-dimensional screen coordinates, preliminarily locate the position of such elements on the screen, and perform target recognition on this basis to improve recognition efficiency. The following steps are included:

[0070] The recognition server outputs the box selection result containing complex superimposed elements of unknown information. The server refers to a machine with an inference card for image recognition. It can be a centralized server on board or a separate computer. The box selection result refers to the result of image recognition as target box information. The target box information includes the size of the target box and the position of the target box, which is similar to the box of face / vehicle recognition.

[0071] Get the color distribution in the frame selection result image and remove the color of the background part;

[0072] Perform grayscale processing on the image after background removal to extract contour lines;

[0073] Obtaining the contour lines of all complex overlay elements of unknown information for overlay drawing means obtaining the contour lines of all complex overlay elements of unknown information, which refers to the contour lines of all elements.

[0074] The recognition server can be a centralized server on the ship or a separate computer. The frame selection result obtains the target frame information, which includes the size and position of the target frame.

[0075] The above-mentioned overlay elements are superimposed on the video stream and then output on the screen. The video stream is processed in a dual-threaded manner, namely the stream pulling thread and the processing thread. The stream pulling thread is used to pull the video stream in real time and cache the obtained image frames; the processing thread obtains the latest image frame in the cache, performs distortion correction, and passes the image to the recognition server, and displays the real-time image frame as the software background.

[0076] Furthermore, the stream pulling thread triggers the task of pulling video streams regularly, and the time interval for a single task execution is fixed, which is generally set according to the frame rate of the video stream to ensure the quality of the stream pulling. The task execution interval of the processing thread will be adaptively adjusted according to the real-time frame rate displayed by the software to ensure the user experience.

[0077] Finally, when displaying the ship navigation situation awareness system on a domestic computing platform, due to differences in hardware performance, different devices and user configuration habits (such as the number of displayed layers), the display effects are different, and the display strategy needs to be adjusted according to the software implementation status.

[0078] For the display of the ship navigation situation awareness system, the refresh rate of the video stream background must be guaranteed first, and the minimum refresh rate and dynamic adjustment refresh rate must be set. The minimum refresh rate refers to the refresh rate that the user can accept; the dynamic adjustment refresh rate refers to the refresh rate limit when dynamic adjustment optimization is performed. Set the minimum refresh rate to f1, the dynamic adjustment refresh rate to f2, and the real-time frame rate of the device to f. When f < f2, the user is prompted to change the display strategy; if f < f1, the software automatically changes the display strategy, and the display strategy is changed in a step-by-step manner.

[0079] The configuration items in the display policy are as follows:

[0080] For the superimposed drawing display of fixed object elements and recognition results: the superimposed drawing frequency of recognition results and the image recognition frequency are simultaneously reduced to reduce the consumption of computer resources.

[0081] Drawing and displaying of complex superimposed elements of unknown information: including adjusting the contour recognition frequency of distant objects and the contour recognition frequency of nearby objects.

[0082] The frequency of contour recognition of distant objects has a higher priority than that of nearby objects, that is, when computer performance is limited, the frequency of contour recognition of distant objects is reduced first. When the recognition frequencies of the two objects are reduced to a limit, the recognized contour is offset accordingly according to the change of the target screen position, and the movement of the recognized contour on the screen is smoothed to improve the display effect.

[0083] For custom overlay element drawing: custom overlay element drawing frequency. According to user needs, the drawing frequency of each custom overlay element is set separately, and the drawing frequency of custom overlay elements that users do not pay attention to is reduced first.

[0084] As mentioned above, by presetting multiple display strategies, each preset strategy is preset for different configuration items. According to the performance of domestic machines and user habits, when the software is running, according to the comparison results of the current frame rate f, the minimum refresh rate f1 / dynamically adjusted refresh rate f2, automatic / manual step-by-step adjustments are made to ensure the smoothness of the display end of the ship navigation situation awareness system on the domestic platform.

[0085] The embodiment of the present invention is a display optimization method based on a ship navigation situation awareness system, which disassembles the three-dimensional engine function, replaces it with corresponding modules, and adaptively optimizes the display frame rate. Among them, the three-dimensional engine function is disassembled into two-dimensional coordinate conversion, superimposed information drawing, and video stream processing and display. The three-dimensional engine is replaced by replacing the corresponding functional modules. At the same time, by setting a step-by-step display strategy, the display frame rate is adaptively optimized, and finally the display effect of the ship navigation situation awareness system on the domestic platform is similar to that on the non-domestic hardware platform, ensuring the user experience.

[0086] Example 2

[0087] This embodiment provides a ship navigation situation awareness system, including a camera and a display control computer, wherein the display control computer is provided with a two-dimensional and three-dimensional coordinate conversion module, an overlay information drawing module and a video stream display module, wherein:

[0088] The two-dimensional and three-dimensional coordinate conversion module establishes a camera coordinate system according to the camera position and posture information, converts the world coordinates into the camera coordinates based on the camera coordinate system, sets up a virtual field, uses an algorithm to achieve the conversion of the two-dimensional and three-dimensional coordinate systems, establishes a projection coordinate system through the camera's horizontal / vertical field of view and focal length and other parameters, converts the camera coordinates into projection coordinates, i.e., two-dimensional screen coordinates, and converts the longitude and latitude coordinates into two-dimensional screen coordinates for displaying the superimposed information position and drawing the superimposed information, and converts the two-dimensional screen coordinates into longitude and latitude coordinates for distance measurement, position measurement and target fusion;

[0089] A superimposed information drawing module calculates the boundaries of various superimposed elements through the two-dimensional and three-dimensional coordinate conversion module, and draws various superimposed elements, wherein the superimposed elements include fixed object mark elements, user-defined superimposed elements, and complex superimposed elements with unknown information;

[0090] The video stream display module processes and displays the video stream and improves the video stream display frame rate by optimizing the video stream processing and display;

[0091] Then, the embedded stepped display strategy algorithm is used to achieve adaptive optimization of the display frame rate, specifically by adjusting the configuration items to reduce the pressure on computer graphics rendering.

[0092] It should be clear that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A display optimization method based on a ship navigation situation awareness system, characterized in that: The display optimization method includes a three-dimensional engine function disassembly and replacement link and a display frame rate adaptive optimization link. In the three-dimensional engine function disassembly link: S1. The 3D engine function is decomposed into 2D and 3D coordinate conversion, video stream background overlay display and overlay information drawing. The 3D engine obtains longitude and latitude coordinates by modeling the earth, and establishes a world coordinate system based on them; S2. 2D and 3D coordinate conversion: establish a camera coordinate system according to the camera position and posture information, convert the world coordinates to the camera coordinates based on the camera coordinate system, set up a virtual field, use the algorithm to achieve the conversion of the 2D and 3D coordinate systems, establish a projection coordinate system through the camera's horizontal / vertical field of view and focal length and other parameters, convert the camera coordinates to projection coordinates, i.e. 2D screen coordinates, the longitude and latitude coordinates to 2D screen coordinates are used for superimposed information position display and superimposed information drawing, and the 2D screen coordinates are converted to longitude and latitude coordinates for distance measurement, position measurement and target fusion; S3. Drawing of superimposed information, calculating the boundaries of various superimposed elements through the two-dimensional and three-dimensional coordinate conversion, and drawing various superimposed elements, the superimposed elements include fixed object elements, custom superimposed elements and complex superimposed elements with unknown information; S4. Video stream processing and display, optimize video stream processing and display, and improve video stream display frame rate; In the display frame rate adaptive optimization link: S5. The display frame rate adaptive optimization is achieved by setting a variety of display strategies to reduce the pressure of computer graphics rendering.

2. A display optimization method based on a ship navigation situation awareness system according to claim 1, characterized in that: In S2, the two-dimensional and three-dimensional coordinate transformation specifically includes the following transformation steps: S21. Establishing a camera coordinate system based on the position and posture information of the camera; S22. Convert the longitude and latitude coordinates into world coordinates by calculation; S23. Converting the world coordinates to the camera coordinates based on the camera coordinate system; S24. Establishing a projection coordinate system through the camera's horizontal / vertical field of view angle and focal length and other parameters; S25. Convert the camera coordinates into projection coordinates, that is, two-dimensional screen coordinates.

3. The display optimization method based on the ship navigation situation awareness system according to claim 2 is characterized in that: The two-dimensional and three-dimensional coordinate conversion also includes the following conversion steps: S26. Convert the two-dimensional coordinates into camera coordinates through the projection coordinate system; S27. Convert the camera coordinates into world coordinates through the camera coordinate system; S28. Convert the world coordinates into longitude and latitude coordinates by longitude and latitude calculation.

4. The display optimization method based on the ship navigation situation awareness system according to claim 1 is characterized in that: In S3, the fixed object marker elements are specifically drawn in a manner of preprocessing the fixed object marker elements, simplifying the number of displayed faces and complexity, saving the presets, and calling and drawing them during operation.

5. The display optimization method for displaying a ship navigation situation awareness system according to claim 1, characterized in that: In S3, the custom overlay element is drawn in a specific manner of converting the latitude and longitude points of the boundary points / key points of the custom overlay element into screen coordinate points to form boundary / key screen coordinate points (sets), and drawing the custom overlay element using a polygon drawing algorithm.

6. The display optimization method for displaying a ship navigation situation awareness system according to claim 1, characterized in that: In S3, drawing the unknown information complex overlay element includes the following steps: S31. Output the selection result through the server; S32. Obtain the color distribution in the frame selection result image, and remove the background part by color; S33. grayscale processing is performed on the image after background removal to extract contour lines; S34. Convert the contour line from relative coordinates to screen absolute coordinates; S35. Obtain all contour lines for overlay drawing.

7. The display optimization method based on the ship navigation situation awareness system according to claim 1 is characterized in that: In S4, the video stream processing and display includes a stream pulling thread and a processing thread. The stream pulling thread is used to pull the video stream in real time and cache the acquired image frames. The processing thread obtains the latest image frame in the cache, performs distortion correction, and transmits the image to the server, and displays the real-time image frame as the software background.

8. The display optimization method based on the ship navigation situation awareness system according to claim 7 is characterized in that: The wire pulling process triggers the task of pulling the video stream periodically. The time interval for executing the task of pulling the video stream once is fixed. The time interval is set according to the frame rate of the video stream. The execution interval of the processing thread task is adaptively adjusted according to the real-time frame rate displayed by the software.

9. The display optimization method based on the ship navigation situation awareness system according to claim 1 is characterized in that: In S5, the adaptive optimization of the display strategy is specifically to adjust the configuration items, and the configuration items include: S51. Adjust the frequency of drawing the fixed object elements and the recognition results and the frequency of transmitting them to the image recognition server; S52. Adjust the contour recognition frequency of distant objects and the contour recognition frequency of nearby objects; S53. Adjust the drawing frequency of custom overlay elements.

10. A ship navigation situation awareness system, comprising a camera and a display and control computer, characterized in that: The display control computer is provided with a two-dimensional and three-dimensional coordinate conversion module, an overlay information drawing module and a video stream display module, wherein: The two-dimensional and three-dimensional coordinate conversion module establishes a camera coordinate system according to the camera position and posture information, converts the world coordinates into the camera coordinates based on the camera coordinate system, sets up a virtual field, uses an algorithm to achieve the conversion of the two-dimensional and three-dimensional coordinate systems, establishes a projection coordinate system through the camera's horizontal / vertical field of view and focal length and other parameters, converts the camera coordinates into projection coordinates, i.e., two-dimensional screen coordinates, and converts the longitude and latitude coordinates into two-dimensional screen coordinates for displaying the superimposed information position and drawing the superimposed information, and converts the two-dimensional screen coordinates into longitude and latitude coordinates for distance measurement, position measurement and target fusion; A superimposed information drawing module calculates the boundaries of various superimposed elements through the two-dimensional and three-dimensional coordinate conversion module, and draws various superimposed elements, wherein the superimposed elements include fixed object mark elements, user-defined superimposed elements, and complex superimposed elements with unknown information; The video stream display module processes and displays the video stream and improves the video stream display frame rate by optimizing the video stream processing and display; A stepped display strategy algorithm is embedded to achieve adaptive optimization of display frame rate, specifically by adjusting configuration items to reduce the pressure of computer graphics rendering.

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