A data transmission system based on the integration of two networks

Abstract

The present invention relates to the field of data transmission technology, and in particular to a data transmission system based on the integration of two networks. The system determines a target block size by performing connected domain analysis on a basic frame, so that an initial image block obtained by subsequent division based on the target block size is subjected to intra-frame coding. Intra-frame coding is achieved by using a relatively small number of target image blocks that are not subjected to secondary differentiation, thereby avoiding excessive reduction in coding efficiency due to the introduction of intra-frame coding in non-key frames. Division is performed as much as possible using a larger target block size, effectively reducing the amount of calculation, thereby ensuring a smaller reduction in coding efficiency. Differential processing is performed on a reference image block to obtain a second differential frame, thereby increasing the difficulty of recovering valid data from a frame to be compressed, thereby ensuring the security of video data transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of data transmission, and in particular to a data transmission system based on the integration of two networks. Background Art

[0002] At present, video data transmission usually requires encoding processing of the video data. The image frames in the video data are usually divided into key frames, predicted frames and bidirectional predicted frames for encoding. The key frames retain the complete image data, the predicted frames are represented by the residual with the reference frames, and the bidirectional predicted frames refer to the previous and next reference frames at the same time, and calculate the difference between the current frame and the previous and next frames to represent it.

[0003] In scenarios where real-time video data transmission is highly demanded, usually only key frames and predicted frames are used. The reason is that the bidirectional predicted frames need to wait for the next reference frame, and there will be a large delay in the decoding process. On this basis, a picture group can be formed by the key frames and the predicted frames to determine the insertion timing of the key frames. The length of the picture group has two types: fixed length and dynamic length. The fixed length can be used to insert a key frame at a fixed interval, and the dynamic length is to insert a key frame when the image changes too much. The fixed length of the picture group can reduce the complexity of encoding and decoding and improve data transmission efficiency.

[0004] In addition, in scenarios where video data transmission security requirements are high, especially scenarios where intranet data is transmitted to external network devices, such as emergency communication scenarios, video data needs to be encrypted. Existing technologies usually use more complex encryption algorithms to encrypt key frames to prevent the key frame content containing complete image information from being cracked, and use simpler encryption algorithms to encrypt predicted frames to improve encryption efficiency. Moreover, since the predicted frames are obtained by differential calculation, it is difficult to recover valid information when the key frames are unknown.

[0005] However, in the scenario of using fixed-length image groups, since key frames are inserted at fixed time intervals, some predicted frames may also contain more information. When the above encryption strategy is applied, the predicted frames may be cracked, resulting in the leakage of valid information.

[0006] Therefore, how to improve the security of video data transmission has become an urgent problem to be solved. Summary of the Invention

[0007] In response to the above technical problems, the present invention adopts a technical solution of a data transmission system based on the integration of two networks, the system comprising: a processor and a memory storing a computer program. When the computer program is executed by the processor, the following steps are implemented:

[0008] S101 : When it is obtained that the frame to be compressed transmitted by the internal network switch to the external network device is not a key frame, a key frame corresponding to the frame to be compressed is determined.

[0009] S102: Determine a first differential frame according to the frame to be compressed and the key frame.

[0010] S103: Binarize the first differential frame to obtain a basic frame.

[0011] S104: If the basic frame meets a first preset condition, perform a connected domain analysis on the basic frame to obtain M connected domains, where M is a positive integer.

[0012] S105 : For any connected domain, determine the bounding box information corresponding to the connected domain.

[0013] S106 , determining the target block size according to each connected domain and the bounding box information corresponding to each connected domain.

[0014] S107 : Divide the first differential frame into N initial image blocks according to the target block size, where N is a positive integer.

[0015] S108 , determining, based on each initial image block, a plurality of reference image blocks, a plurality of target image blocks, and corresponding relationships between the reference image blocks and the target image blocks.

[0016] S109, in the first differential frame, perform differential processing on each reference image block according to the target image block corresponding to each reference image block, update the first differential frame to obtain a second differential frame, and determine the transmission data corresponding to the frame to be compressed according to the second differential frame.

[0017] The present invention has at least the following beneficial effects: by performing connected domain analysis on the basic frame, the target block size is determined, so that the initial image block obtained by subsequent division based on the target block size is intra-frame encoded, and intra-frame encoding is achieved by using fewer target image blocks that are not subjected to secondary differentiation, thereby avoiding excessive reduction in coding efficiency due to the introduction of intra-frame coding in non-key frames, and dividing with a larger target block size as much as possible, effectively reducing the amount of calculation, thereby ensuring a small reduction in coding efficiency, performing differential processing on the reference image block to obtain a second differential frame, making it more difficult to recover valid data from the frame to be compressed, thereby ensuring the security of video data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0019] Figure 1 A flowchart of a computer program executed by a processor in a data transmission system based on dual-network integration is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It is understood that, where appropriate, the above-mentioned terms used to distinguish similar objects can be interchanged so that the present invention can also implement other embodiments other than the above-mentioned illustrated embodiments or described embodiments. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0022] This embodiment provides a data transmission system based on the integration of two networks, such as Figure 1 FIG2 is a flow chart of a computer program executed by a processor in a data transmission system based on dual-network integration provided by an embodiment of the present invention. The data transmission system based on dual-network integration includes a processor and a memory storing a computer program. When the computer program is executed by the processor, the following steps are implemented:

[0023] S101, when it is obtained that the frame to be compressed transmitted by the intranet switch to the extranet device is not a key frame, determining the key frame corresponding to the frame to be compressed;

[0024] S102, determining a first differential frame according to the frame to be compressed and the key frame;

[0025] S103, performing binarization processing on the first differential frame to obtain a base frame;

[0026] S104, if the basic frame meets the first preset condition, performing a connected domain analysis on the basic frame to obtain M connected domains, where M is a positive integer;

[0027] S105, for any connected domain, determining the bounding box information corresponding to the connected domain;

[0028] S106, determining the target block size based on each connected domain and the bounding box information corresponding to each connected domain;

[0029] S107, dividing the first differential frame into N initial image blocks according to the target block size, where N is a positive integer;

[0030] S108, determining, based on each initial image block, a plurality of reference image blocks, a plurality of target image blocks, and corresponding relationships between the reference image blocks and the target image blocks;

[0031] S109, in the first differential frame, perform differential processing on each reference image block according to the target image block corresponding to each reference image block, update the first differential frame to obtain a second differential frame, and determine the transmission data corresponding to the frame to be compressed according to the second differential frame.

[0032] Among them, when the intranet switch transmits video data to the external network device, it adopts the method of no bidirectional prediction frame and fixed-length image group to improve transmission efficiency.

[0033] The first differential frame can be obtained by subtracting the frame to be compressed from the key frame point by point, and then performing non-negative processing on the subtraction result. The non-negative processing can be achieved by using an absolute value method, an offset method, or the like.

[0034] The basic frame may refer to the result obtained by binarizing the first differential frame with zero as the threshold, that is, in the first differential frame, pixel values ​​greater than zero are updated to 1, and pixel values ​​equal to zero are updated to 0 to obtain the basic frame.

[0035] It should be noted that the connected domain analysis process needs to traverse all pixel points. The larger the image size of the frame to be compressed, the longer the connected domain analysis takes. The implementer can add the extra time added by the overall method of this embodiment to the time taken to transmit video data in a manner without bidirectional prediction frames and fixed-length image groups, and compare it with the second time taken to transmit video in a manner without bidirectional prediction frames and dynamic-length image groups. The content of this embodiment shall be executed only when the image size of the frame to be compressed can satisfy that the first time taken is less than the second time taken.

[0036] The bounding box information may include the coordinates of the upper left corner and the lower right corner of the minimum regular circumscribed rectangle of the corresponding connected region.

[0037] Specifically, according to the target block size, the first differential frame is divided into N initial image blocks with the upper left corner of the first differential frame as the starting point.

[0038] In the first differential frame, for any reference image block, a differential calculation is performed between the reference image block and the target image block corresponding to the reference image block, and the pixel value of each pixel point in the reference image block is updated with the differential calculation result. The first differential frame is updated, and all reference image blocks are traversed to obtain the second differential frame.

[0039] In a specific embodiment, the system further includes a first satellite portable station, a second satellite portable station, a router, an intranet switch, and an extranet device;

[0040] The first satellite portable station and the second satellite portable station form a local area network through a satellite, the external network device accesses the first satellite portable station to connect to the local area network, and the internal network switch accesses the second satellite portable station through the router to connect to the local area network.

[0041] In a specific embodiment, when the intranet switch transmits video data to the external network device through the local area network, the key frames in the video data are encrypted using a first encryption algorithm and then transmitted, and the non-key frames in the video data are encrypted using a second encryption algorithm and then transmitted.

[0042] In a specific implementation, the encryption security and encryption complexity of the first encryption algorithm are greater than those of the second encryption algorithm.

[0043] The first encryption algorithm may be an AES encryption algorithm, an RSA encryption algorithm, or the like, and the second encryption algorithm may be a stream encryption algorithm, or the like.

[0044] In a specific embodiment, when it is obtained that the frame to be compressed transmitted by the intranet switch to the extranet device is not a key frame, determining the key frame corresponding to the frame to be compressed includes:

[0045] If the acquisition time point corresponding to the frame to be compressed is different from the reference time points corresponding to the K preset image groups, it is determined that the frame to be compressed is not a key frame;

[0046] A key frame in a preset image group corresponding to a reference time point closest to the acquisition time point and smaller than the acquisition time point is determined as a key frame corresponding to the frame to be compressed.

[0047] Here, K is a positive integer. Since the present embodiment adopts an image group of fixed length, the reference time point for inserting a key frame into each preset image group can be determined according to a fixed time interval.

[0048] The preset image group corresponding to the reference time point that is closest to the acquisition time point and smaller than the acquisition time point is the preset image group to which the frame to be compressed belongs.

[0049] In a specific implementation, the first preset condition is: the sum of the pixel values ​​of all pixels in the basic frame is greater than a first preset threshold.

[0050] Among them, the first preset threshold can be set by the implementer. When the sum of the pixel values ​​of all pixels in the basic frame is greater than the first preset threshold, it can indicate that the frame to be compressed has a sudden change in the picture compared to its corresponding key frame.

[0051] In a specific embodiment, the bounding box information includes a bounding box size;

[0052] The determining of the target block size according to each connected domain and the bounding box information corresponding to each connected domain includes:

[0053] Determine the number of covered pixels corresponding to the bounding box information according to the bounding box size;

[0054] Calculating a pixel ratio based on the number of covered pixels and the number of statistical pixels with a pixel value of 1 in the connected domain;

[0055] Mapping to obtain a reference size corresponding to the connected domain according to the pixel ratio and a preset mapping function;

[0056] The target block size is determined according to the reference sizes corresponding to the connected domains.

[0057] The width of the bounding box is determined by the absolute value of the difference between the horizontal coordinates of the upper left corner and the lower right corner, and the height of the bounding box is determined by the absolute value of the difference between the vertical coordinates of the upper left corner and the lower right corner. The size of the bounding box can be determined by the width and height of the bounding box.

[0058] The product of the bounding box width and the bounding box height is the number of covered pixels corresponding to the bounding box information.

[0059] The pixel ratio can be obtained by comparing the number of counted pixels with the number of covered pixels.

[0060] The preset mapping function can be y=a×ln(b×x+1)+1, where x is the pixel ratio, y represents the mapping value, a is the first adjustment coefficient, and b is the second adjustment coefficient. Both the first adjustment coefficient and the second adjustment coefficient can be set to a value greater than 1. The first adjustment coefficient can be used to control the upper limit of the mapping value, and the second adjustment coefficient ensures the increase in the rate of change of the mapping value with the pixel ratio. In this embodiment, a is set to 14 and b is set to 2. The mapping value is then rounded up to obtain the reference size. It should be noted that in this embodiment, the default block size is the same as the width and height, so only a single value needs to be determined to determine the reference size.

[0061] In a specific implementation, determining the target block size according to the reference sizes corresponding to the connected domains includes:

[0062] For any connected domain, determine a reference size interval according to the reference size corresponding to the connected domain and a preset offset value;

[0063] Perform histogram analysis based on the reference size intervals corresponding to each connected domain to obtain several intermediate sizes;

[0064] The target block size is determined from all intermediate sizes.

[0065] Among them, the preset offset value can be an integer greater than or equal to zero. Generally, the larger the preset offset value is, the more intermediate sizes are obtained, and the determined target block size is more likely to be the optimal block size. The implementer can adjust the preset offset value according to the actual transmission rate requirements.

[0066] Specifically, the statistical value of each integer is initialized to zero. For any reference size interval, the statistical value corresponding to each integer included in the reference size interval is increased by 1. By traversing all reference size intervals, a histogram of the statistical values ​​of each integer can be obtained.

[0067] The statistical value threshold can be determined according to the statistical values ​​corresponding to each integer. The specific determination method can adopt the mean method, Otsu threshold method, etc., and the integer corresponding to the statistical value greater than the statistical value threshold is used as the intermediate size.

[0068] It should be noted that the implementer can further filter the intermediate sizes based on a priori information. For example, if the target block size is required to be an odd number, the even numbers in the intermediate sizes will be filtered out.

[0069] In a specific implementation, determining the target block size from all intermediate sizes includes:

[0070] For any intermediate size, the differential frame is segmented according to the intermediate size to obtain a plurality of intermediate image blocks and a summation result of pixel values ​​corresponding to each intermediate image block;

[0071] Determine the size evaluation value corresponding to the intermediate size according to the sum of the pixel values ​​corresponding to each intermediate image block;

[0072] The middle size with the highest middle size evaluation value is selected as the target block size.

[0073] Among them, determining the size evaluation value corresponding to the intermediate size based on the sum of the pixel values ​​corresponding to each intermediate image block may mean determining the image block proportion of each intermediate image block based on the sum of the pixel values ​​corresponding to each intermediate image block and the corresponding intermediate size, and retaining the image block proportion greater than the image block proportion threshold by determining the image block proportion threshold based on each image block proportion, and taking the average of the retained image block proportions as the size evaluation value corresponding to the intermediate size. The image block proportion threshold can be used to eliminate intermediate image blocks that do not contain valid information.

[0074] In a specific embodiment, the determining, based on each initial image block, a plurality of reference image blocks, a plurality of target image blocks, and the corresponding relationships between the reference image blocks and the target image blocks from each initial image block includes:

[0075] Each initial image block is flattened into an initial vector, and each initial vector is subjected to dimensionality reduction processing to obtain several reduced-dimensionality vectors;

[0076] For any initial vector, determine the dimension-reduced vector closest to the initial vector as the associated vector corresponding to the initial vector;

[0077] For any reduced-dimensionality vector, from the initial vectors that use the reduced-dimensionality vector as the associated vector, select the initial vector closest to the reduced-dimensionality vector as the target vector, and all other initial vectors are used as reference vectors corresponding to the target vector;

[0078] The initial image block corresponding to the target vector is used as the target image block, and the initial image block corresponding to the reference vector is used as the reference image block.

[0079] Among them, the dimensionality reduction processing can adopt the principal component analysis method, and the number of dimensionality reduction vectors should be as small as possible while satisfying that the cumulative variance contribution rate of each dimensionality reduction vector is greater than the preset contribution rate threshold, so as to improve the execution efficiency of the principal component analysis method.

[0080] The distance between vectors can be calculated using the cosine distance.

[0081] Specifically, by means of dimensionality reduction analysis, reference image blocks and target image blocks with similar information can be determined, thereby improving the compression rate of the reference image blocks through differential calculation, and only retaining a small number of target image blocks, further improving the compression rate.

[0082] In this embodiment, the target block size is determined by performing connected domain analysis on the basic frame, so that the initial image block obtained by subsequent division based on the target block size is intra-frame encoded, and intra-frame encoding is achieved by using fewer target image blocks that are not subjected to secondary differentiation, thereby avoiding excessive reduction in coding efficiency due to introducing intra-frame coding in non-key frames, and dividing with a larger target block size as much as possible, effectively reducing the amount of calculation, thereby ensuring a small reduction in coding efficiency, and performing differential processing on the reference image block to obtain a second differential frame, which increases the difficulty of recovering valid data from the frame to be compressed, thereby ensuring the security of video data transmission.

[0083] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above in terms of preferred embodiments, they are not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A data transmission system based on the integration of two networks, characterized in that: The system includes: a processor and a memory storing a computer program. When the computer program is executed by the processor, the following steps are implemented: S101, when it is obtained that the frame to be compressed transmitted by the intranet switch to the extranet device is not a key frame, determining the key frame corresponding to the frame to be compressed; S102, determining a first differential frame according to the frame to be compressed and the key frame; S103, performing binarization processing on the first differential frame to obtain a base frame; S104, if the basic frame meets the first preset condition, performing a connected domain analysis on the basic frame to obtain M connected domains, where M is a positive integer; S105, for any connected domain, determining the bounding box information corresponding to the connected domain; S106, determining the target block size based on each connected domain and the bounding box information corresponding to each connected domain; S107, dividing the first differential frame into N initial image blocks according to the target block size, where N is a positive integer; S108, determining, based on each initial image block, a plurality of reference image blocks, a plurality of target image blocks, and corresponding relationships between the reference image blocks and the target image blocks; S109, in the first differential frame, perform differential processing on each reference image block according to the target image block corresponding to each reference image block, update the first differential frame to obtain a second differential frame, and determine the transmission data corresponding to the frame to be compressed according to the second differential frame.

2. The data transmission system based on the integration of two networks according to claim 1, characterized in that: The system also includes a first satellite portable station, a second satellite portable station, a router, an intranet switch and an extranet device; The first satellite portable station and the second satellite portable station form a local area network through a satellite, the external network device accesses the first satellite portable station to connect to the local area network, and the internal network switch accesses the second satellite portable station through the router to connect to the local area network.

3. The data transmission system based on the integration of two networks according to claim 2, characterized in that: When the intranet switch transmits video data to the external network device through the local area network, key frames in the video data are encrypted using a first encryption algorithm and then transmitted, and non-key frames in the video data are encrypted using a second encryption algorithm and then transmitted.

4. The data transmission system based on the integration of two networks according to claim 3, characterized in that: The encryption security and encryption complexity of the first encryption algorithm are both greater than those of the second encryption algorithm.

5. The data transmission system based on the integration of two networks according to claim 1, characterized in that: When it is obtained that the frame to be compressed transmitted by the intranet switch to the extranet device is not a key frame, determining the key frame corresponding to the frame to be compressed includes: If the acquisition time point corresponding to the frame to be compressed is different from the reference time points corresponding to the K preset image groups, it is determined that the frame to be compressed is not a key frame; A key frame in a preset image group corresponding to a reference time point closest to the acquisition time point and smaller than the acquisition time point is determined as a key frame corresponding to the frame to be compressed.

6. The data transmission system based on the integration of two networks according to claim 1, characterized in that: The first preset condition is that the sum of the pixel values ​​of all pixels in the basic frame is greater than a first preset threshold.

7. The data transmission system based on the integration of two networks according to claim 1, characterized in that: The bounding box information includes the bounding box size; The determining of the target block size according to each connected domain and the bounding box information corresponding to each connected domain includes: Determine the number of covered pixels corresponding to the bounding box information according to the bounding box size; Calculating a pixel ratio based on the number of covered pixels and the number of statistical pixels with a pixel value of 1 in the connected domain; Mapping to obtain a reference size corresponding to the connected domain according to the pixel ratio and a preset mapping function; The target block size is determined according to the reference sizes corresponding to the connected domains.

8. The data transmission system based on the integration of two networks according to claim 7, characterized in that: The determining the target block size according to the reference sizes corresponding to the connected domains includes: For any connected domain, determine a reference size interval according to the reference size corresponding to the connected domain and a preset offset value; Perform histogram analysis based on the reference size intervals corresponding to each connected domain to obtain several intermediate sizes; The target block size is determined from all intermediate sizes.

9. The data transmission system based on the integration of two networks according to claim 8, characterized in that: The determining the target block size from all intermediate sizes includes: For any intermediate size, the differential frame is segmented according to the intermediate size to obtain a plurality of intermediate image blocks and a summation result of pixel values ​​corresponding to each intermediate image block; Determine the size evaluation value corresponding to the intermediate size according to the sum of the pixel values ​​corresponding to each intermediate image block; The middle size with the highest middle size evaluation value is selected as the target block size.

10. The data transmission system based on the integration of two networks according to claim 1, characterized in that: The determining, based on each initial image block, a plurality of reference image blocks, a plurality of target image blocks, and corresponding relationships between the reference image blocks and the target image blocks from each initial image block includes: Each initial image block is flattened into an initial vector, and each initial vector is subjected to dimensionality reduction processing to obtain several reduced-dimensionality vectors; For any initial vector, determine the dimension-reduced vector closest to the initial vector as the associated vector corresponding to the initial vector; For any reduced-dimensionality vector, from the initial vectors that use the reduced-dimensionality vector as the associated vector, select the initial vector closest to the reduced-dimensionality vector as the target vector, and all other initial vectors are used as reference vectors corresponding to the target vector; The initial image block corresponding to the target vector is used as the target image block, and the initial image block corresponding to the reference vector is used as the reference image block.

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