Vector geospatial data blind watermarking method, device and equipment and medium

Abstract

The invention discloses a vector geospatial data blind watermarking method and device, equipment and a medium, and relates to the technical field of data security, and the method comprises the steps: converting a preset watermark character string into a binary bit stream through employing a target coding mode, so as to obtain a corresponding character string length, carrying out the normalization processing of each original coordinate point, so as to obtain a normalized coordinate point, determining a target bit value corresponding to each normalized coordinate point based on the length of the character string; screening out a target coordinate point from the normalized coordinate points based on the target dynamic parameter set and the character string length, and setting a dynamic flag bit corresponding to the target coordinate point; and carrying out watermark embedding on each target coordinate point based on the target bit value and the target watermark embedding position so as to carry out blind watermarking on the vector geographic space data. The watermark adding range in the vector map spatial data is determined by using the dynamic parameter set, so that the watermark range can be adjusted, and the problem of low efficiency of adding watermarks to large-scale vector geographic spatial data is solved.

Description

Technical Field

[0001] The present invention relates to the field of data security technology, and in particular to a vector geospatial data blind watermarking method, device, equipment and medium. Background Art

[0002] The sharing and dissemination of vector geospatial data has brought significant benefits to various fields, but data security and copyright protection issues are also becoming increasingly prominent. Digital watermarking, as a common copyright protection method, is widely used in documents, images, audio, and video. Similarly, applying watermarking technology to vector data can achieve copyright protection and flow traceability, prevent malicious dissemination, and promote the secure sharing of geospatial data.

[0003] Currently, when blind watermarking vector geospatial data, a fixed watermark embedding ratio is usually used. This method has the problem of low watermark embedding efficiency when adding watermarks to large vector data. Therefore, how to perform efficient blind watermarking has become a technical problem that needs to be solved. Summary of the Invention

[0004] In view of this, the present invention aims to provide a method, apparatus, device, and medium for blind watermarking of vector geospatial data. These methods utilize a dynamic parameter set to determine the watermarking range in vector map spatial data, allowing the watermarking range to be adjusted. This solves the problem of inefficient watermarking of large-scale vector geospatial data. The specific solution is as follows:

[0005] In a first aspect, the present application provides a blind watermarking method for vector geospatial data, comprising:

[0006] Acquire target vector geospatial data, and select a target watermark embedding position corresponding to the target vector geospatial data;

[0007] Converting a preset watermark character string into a binary bit stream using a target encoding method to obtain a character string length corresponding to the preset watermark character string, normalizing each original coordinate point corresponding to the target watermark embedding position to obtain a normalized coordinate point corresponding to each original coordinate point, and determining a target bit value corresponding to each normalized coordinate point based on the character string length and a hash algorithm; wherein the target bit value is a bit value in the binary bit stream;

[0008] Constructing a target dynamic parameter set, filtering a target coordinate point from each of the normalized coordinate points based on the target dynamic parameter set and the string length, and setting a dynamic flag corresponding to the target coordinate point; wherein the target dynamic parameter set is used to determine a filtering range corresponding to the target coordinate point, and the dynamic flag is used to determine a target watermark embedding position, and the target watermark embedding position is any digit in the X coordinate of the original coordinate point;

[0009] Based on the target bit value and the target watermark embedding position, each target coordinate point is watermarked to obtain a corresponding printed coordinate point, and each printed coordinate point is denormalized to blindly watermark the target vector geographic spatial data; wherein the printed coordinate point is the coordinate point after the watermark is added.

[0010] Optionally, the normalizing the original coordinate points corresponding to the target watermark embedding position includes:

[0011] Determine the maximum X coordinate value, the maximum Y coordinate value, the minimum X coordinate value, and the minimum Y coordinate value from each of the original coordinate points;

[0012] Obtaining a first difference between the X coordinate of the current original coordinate point and the minimum X coordinate value, obtaining a second difference between the maximum X coordinate value and the minimum X coordinate value, and normalizing the X coordinate of the current original coordinate point based on the first difference value and the second difference value;

[0013] Obtain a third difference between the Y coordinate of the current original coordinate point and the minimum Y coordinate value, obtain a fourth difference between the maximum Y coordinate value and the minimum Y coordinate value, and normalize the Y coordinate of the current original coordinate point based on the third difference and the fourth difference.

[0014] Optionally, determining the target bit value corresponding to each of the normalized coordinate points based on the character string length and a hash algorithm includes:

[0015] The target index values corresponding to the normalized coordinate points are obtained based on the character string length and the hash algorithm, and the target bit values corresponding to the normalized coordinate points are determined according to the target index values.

[0016] Optionally, obtaining the target index value corresponding to each of the normalized coordinate points based on the string length and a hash algorithm includes:

[0017] Determining a target integer parameter, and performing integer processing on the Y coordinate of each of the normalized coordinate points according to the target integer parameter to obtain a corresponding integerized Y coordinate; wherein the target integer parameter is used to determine the number of digits of the integerized Y coordinate;

[0018] The target index value corresponding to each of the normalized coordinate points is obtained according to the integer Y coordinate, the string length, and a hash algorithm.

[0019] Optionally, embedding a watermark at each target coordinate point based on the target bit value and the target watermark embedding position includes:

[0020] If the target bit value is zero and the value to be modified corresponding to the target watermark embedding position is an odd number, then adding one to the value to be modified;

[0021] If the target bit value is one, and the value to be modified corresponding to the target watermark embedding position is an even number, an addition operation is performed on the value to be modified.

[0022] Optionally, after denormalizing each of the printed coordinate points, the method further includes:

[0023] Extracting the printed coordinate points from the target vector geographic spatial data, and obtaining the target index values corresponding to the printed coordinate points based on the character string length and a hash algorithm;

[0024] Determine the dynamic flag corresponding to the printed coordinate point, and obtain the target bit value corresponding to each printed coordinate point based on the dynamic flag;

[0025] The target bit values are concatenated based on the target index values to obtain the binary bit stream, and the preset watermark character string is obtained based on the binary bit stream.

[0026] In a second aspect, the present application provides a vector geospatial data blind watermarking device, comprising:

[0027] A data acquisition module is used to acquire target vector geographic spatial data and select a target watermark embedding position corresponding to the target vector geographic spatial data;

[0028] a bit value determination module, configured to convert a preset watermark character string into a binary bit stream using a target encoding method to obtain a character string length corresponding to the preset watermark character string, perform normalization processing on each original coordinate point corresponding to the target watermark embedding position to obtain a normalized coordinate point corresponding to each of the original coordinate points, and determine a target bit value corresponding to each of the normalized coordinate points based on the character string length and a hash algorithm; wherein the target bit value is a bit value in the binary bit stream;

[0029] a flag setting module, configured to construct a target dynamic parameter set, filter a target coordinate point from each of the normalized coordinate points based on the target dynamic parameter set and the string length, and set a dynamic flag corresponding to the target coordinate point; wherein the target dynamic parameter set is used to determine a filtering range corresponding to the target coordinate point, and the dynamic flag is used to determine a target watermark embedding position, wherein the target watermark embedding position is any digit in the X coordinate of the original coordinate point;

[0030] A watermark embedding module is used to embed a watermark on each of the target coordinate points based on the target bit value and the target watermark embedding position to obtain a corresponding printed coordinate point, and to denormalize each of the printed coordinate points to blindly watermark the target vector geospatial data; wherein the printed coordinate point is the coordinate point after the watermark is added.

[0031] In a third aspect, the present application provides an electronic device, comprising:

[0032] Memory, used to store computer programs;

[0033] A processor is used to execute the computer program to implement the aforementioned vector geospatial data blind watermarking method.

[0034] In a fourth aspect, the present application provides a computer-readable storage medium for storing a computer program, which implements the aforementioned vector geospatial data blind watermarking method when executed by a processor.

[0035] The present application first obtains target vector geospatial data, and selects a target watermark embedding position corresponding to the target vector geospatial data, and then uses a target encoding method to convert a preset watermark string into a binary bit stream to obtain the string length corresponding to the preset watermark string, and normalizes each original coordinate point corresponding to the target watermark embedding position to obtain the normalized coordinate point corresponding to each original coordinate point, and determines the target bit value corresponding to each normalized coordinate point based on the string length and the hash algorithm; wherein the target bit value is the bit value in the binary bit stream, and then constructs a target dynamic parameter set, based on the target dynamic parameter set and the The target coordinate point is filtered out from each of the normalized coordinate points based on the string length, and a dynamic flag bit corresponding to the target coordinate point is set; wherein the target dynamic parameter set is used to determine the filtering range corresponding to the target coordinate point, and the dynamic flag bit is used to determine the target watermark embedding position, and the target watermark embedding position is any digit in the X coordinate of the original coordinate point. Finally, based on the target bit value and the target watermark embedding position, each of the target coordinate points is watermarked to obtain a corresponding printed coordinate point, and each of the printed coordinate points is denormalized to perform blind watermarking on the target vector geographic spatial data; wherein the printed coordinate point is the coordinate point after the watermark is added. It can be seen that this application constructs a dynamic parameter set and uses the dynamic parameter set to determine the watermark addition range in the vector map spatial data, so that the watermark range can be adjusted, avoiding the use of a fixed watermark embedding ratio for data blind watermarking, thereby solving the problem of low efficiency in adding watermarks to large-scale vector geographic spatial data; by setting a dynamic flag and dynamically adjusting the watermark addition position according to the dynamic flag, the watermark addition position is made random, thereby improving the applicability and anti-attack capability of the watermark. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0037] Figure 1 This is a flow chart of a blind watermarking method for vector geospatial data disclosed in this application;

[0038] Figure 2 This is a flow chart of a specific blind watermarking method for vector geospatial data disclosed in this application;

[0039] Figure 3This is a flow chart of a vector geospatial data watermark extraction method disclosed in this application;

[0040] Figure 4 This is a flow chart of a specific vector geospatial data watermark extraction method disclosed in this application;

[0041] Figure 5 This is a schematic structural diagram of a blind watermarking device for vector geospatial data disclosed in this application;

[0042] Figure 6 This is a structural diagram of an electronic device disclosed in this application. DETAILED DESCRIPTION

[0043] 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] Currently, the method of blind watermarking vector geospatial data has the problem of low watermark embedding efficiency. To this end, the present application provides a blind watermarking method for vector geospatial data. By utilizing a dynamic parameter set to determine the watermark addition range in vector map spatial data, the watermark range can be adjusted, thereby solving the problem of low efficiency in adding watermarks to large-scale vector geospatial data.

[0045] See also Figure 1 As shown, the embodiment of the present invention discloses a blind watermarking method for vector geospatial data, comprising:

[0046] Step S11: Acquire target vector geographic spatial data, and select a target watermark embedding position corresponding to the target vector geographic spatial data.

[0047] The data blind watermarking process in this implementation is as follows Figure 2 As shown, the process includes selecting the coordinate points where watermarks need to be embedded, normalizing the X and Y coordinates, obtaining the target index values corresponding to the coordinates, and establishing a corresponding relationship between the index values and the target bit values, and finally embedding the watermarks into the vector geographic spatial data.

[0048] In this embodiment, it is first necessary to obtain the target vector geospatial data to be embedded with a watermark, read the point, line, and surface coordinate information in shp (a vector data format), and select the line and surface to be embedded with a watermark (i.e., the target watermark embedding position).

[0049] Step S12: using a target encoding method to convert a preset watermark string into a binary bit stream to obtain a string length corresponding to the preset watermark string, normalizing each original coordinate point corresponding to the target watermark embedding position to obtain a normalized coordinate point corresponding to each original coordinate point, and determining a target bit value corresponding to each normalized coordinate point based on the string length and a hash algorithm; wherein the target bit value is a bit value in the binary bit stream.

[0050] Execute the watermark embedding algorithm for the selected line or surface: a string of the given watermark information (i.e. preset watermark string), encoded into (ie binary bit stream), get the watermark length information .

[0051] In this embodiment, the process of normalizing the original coordinate points corresponding to the target watermark embedding position may specifically include: determining the maximum X coordinate, the maximum Y coordinate, the minimum X coordinate, and the minimum Y coordinate from each original coordinate point; obtaining a first difference between the X coordinate of the current original coordinate point and the minimum X coordinate, obtaining a second difference between the maximum X coordinate and the minimum X coordinate, and normalizing the X coordinate of the current original coordinate point based on the first difference and the second difference; obtaining a third difference between the Y coordinate of the current original coordinate point and the minimum Y coordinate, obtaining a fourth difference between the maximum Y coordinate and the minimum Y coordinate, and normalizing the Y coordinate of the current original coordinate point based on the third difference and the fourth difference. Specifically, a series of coordinate points Normalize, the normalization method is: , , get the new series coordinate points (i.e. normalized coordinate points).

[0052] in, After normalization coordinate, After normalization coordinate, is the maximum value of the above X coordinate, is the minimum value of the above X coordinate, is the maximum value of the above Y coordinate, is the minimum value of the Y coordinate mentioned above.

[0053] In this embodiment, the process of determining the target bit value corresponding to each normalized coordinate point based on the string length and the hash algorithm can specifically include: obtaining the target index value corresponding to each normalized coordinate point based on the string length and the hash algorithm, and determining the target bit value corresponding to each normalized coordinate point based on each target index value. The above process of obtaining the target index value corresponding to each normalized coordinate point based on the string length and the hash algorithm can specifically include: determining a target integer parameter, performing integer processing on the Y coordinate of each normalized coordinate point based on the target integer parameter to obtain the corresponding integerized Y coordinate; wherein the target integer parameter is used to determine the number of digits of the integerized Y coordinate; and obtaining the target index value corresponding to each normalized coordinate point based on the integerized Y coordinate, the string length and the hash algorithm.

[0054] Specifically, the grouping algorithm is performed on the normalized Y coordinate. First, the Y coordinate is normalized to obtain , the goal is to convert floating-point numbers into integers as required. For example, the target integer parameter is selected as , then 123.12345678 is normalized to 123123; next, for each pair of coordinate points ,calculate (i.e., target index value), where the target index value is obtained through a hash algorithm, and its calculation formula is as follows:

[0055] ;

[0056] in, is the private key, hash() uses a keyed hash algorithm.

[0057] Step S13: constructing a target dynamic parameter set, filtering out a target coordinate point from each of the normalized coordinate points based on the target dynamic parameter set and the string length, and setting a dynamic flag corresponding to the target coordinate point; wherein the target dynamic parameter set is used to determine a filtering range corresponding to the target coordinate point, and the dynamic flag is used to determine a target watermark embedding position, and the target watermark embedding position is any digit in the X coordinate of the original coordinate point.

[0058] In this embodiment, it is necessary to perform the screening algorithm on the normalized Y coordinate. First, set a set (i.e. target dynamic parameter set), SET can be manually selected, controlled and adjusted. Then use key2 to calculate ,in, The expression is as follows:

[0059] ;

[0060] If modify is true, the row is selected, the corresponding target index value is recorded, and the watermark adding process continues. , modify the coordinates , extract the corresponding watermark bit value according to the index. Set a dynamic modification flag (i.e. dynamic flag bit), and according to the flag, you can specify the flag bit of the modified coordinate.

[0061] Step S14: embedding a watermark into each of the target coordinate points based on the target bit value and the target watermark embedding position to obtain a corresponding printed coordinate point, and denormalizing each of the printed coordinate points to blindly watermark the target vector geographic spatial data; wherein the printed coordinate point is the coordinate point after adding the watermark.

[0062] In this embodiment, the process of embedding watermarks for each target coordinate point based on the target bit value and the target watermark embedding position may specifically include: if the target bit value is zero, and the value to be modified corresponding to the target watermark embedding position is an odd number, then the value to be modified is added by one; if the target bit value is one, and the value to be modified corresponding to the target watermark embedding position is an even number, then the value to be modified is added by one. Specifically, if the bit (i.e., the target bit value) is 0, then the flag bit is modified to be an even number, i.e., if the original flag bit is an even number, the number remains unchanged, otherwise the bit is added by 1; if the bit is 1, then the flag bit is modified to be an odd number, i.e., if the original flag bit is an odd number, the number remains unchanged, otherwise the bit is added by 1; the choice of flag can be dynamically specified according to the specific scenario to obtain the coordinate point for adding the watermark (i.e. containing printed coordinate points), a series of coordinate points after adding the watermark Denormalize to get Rewrite the shp file to complete the blind watermark operation on the data.

[0063] In this embodiment, after denormalizing each printed coordinate point, it also includes: extracting the printed coordinate point from the target vector geographic space data, and obtaining the target index value corresponding to each printed coordinate point based on the string length and the hash algorithm; determining the dynamic flag corresponding to the printed coordinate point, and obtaining the target bit value corresponding to each printed coordinate point based on the dynamic flag; splicing each target bit value based on each target index value to obtain a binary bit stream, and obtaining a preset watermark string based on the binary bit stream. That is, it supports blind watermark extraction directly on the carrier to which the watermark is added, and supports dynamic adjustment and modification of data points, and is applicable to vector data of various precisions. By setting the dynamic flag and setting the watermark addition range according to the dynamic flag, this method is applicable to vector data of various precisions and can improve the watermark embedding efficiency.

[0064] Experiments have shown that the blind watermark method in this embodiment has strong anti-attack capabilities: in terms of the number of attacks, it can resist attacks such as enlargement, reduction, translation, addition, deletion, modification, and compression; in terms of the intensity of attacks, it can achieve point deletion or compression within 50% without basically affecting the complete watermark extraction.

[0065] It can be seen that this application constructs a dynamic parameter set and uses the dynamic parameter set to determine the watermark addition range in the vector map spatial data, so that the watermark range can be adjusted, avoiding the use of a fixed watermark embedding ratio for data blind watermarking, thereby solving the problem of low efficiency in adding watermarks to large-scale vector geographic spatial data; by setting a dynamic flag and dynamically adjusting the watermark addition position according to the dynamic flag, the watermark addition position is made random, thereby improving the applicability and anti-attack capability of the watermark.

[0066] Based on the above embodiments, this application describes the overall process of blind watermarking of vector geospatial data. In order to make the technical solution in this application more complete, this application will next explain the process of extracting watermarks from vector geospatial data. Figure 3 As shown, the embodiment of the present invention discloses a watermark extraction process, including:

[0067] Step S21: extract the printed coordinate points from the target vector geographic spatial data, and obtain the target index values corresponding to each of the printed coordinate points based on the string length and the hash algorithm, wherein the printed coordinate points are coordinate points to which watermarks have been added, and the string length is the length of the watermark string corresponding to the printed coordinate points.

[0068] In this embodiment, the process of extracting the watermark from the printed coordinate points is as follows: Figure 4 As shown in the figure, first, the point, line and surface coordinate information of the vector geographic spatial data is extracted, and the coordinate points for embedding watermark information (i.e., the printed coordinate points) are selected, the X and Y coordinates of the coordinate points are normalized, and then the index value is extracted using the hash algorithm, and the bit value corresponding to the X coordinate is extracted. Finally, the bit values are spliced based on the index value to obtain the watermark information.

[0069] In this embodiment, first extract the printed coordinate points Normalize, the normalization method is: 、 , get the new series coordinate points The grouping algorithm is performed on the normalized Y coordinate. First, the Y coordinate is normalized according to the embedding parameter prm to obtain ; Secondly, for each pair of coordinate points , calculated using key1 and hash function (i.e., target index value), where the target index value is obtained through a hash algorithm, and its calculation formula is as follows:

[0070] ;

[0071] in, is the known watermark information length (i.e. string length).

[0072] Step S22: determine the dynamic flag corresponding to the printed coordinate point, and obtain the target bit value corresponding to each of the printed coordinate points based on the dynamic flag, wherein the dynamic flag is used to determine the watermark embedding position corresponding to each of the printed coordinate points, and the target bit value is the bit value in the binary bit stream corresponding to the watermark string.

[0073] In this embodiment, before determining the dynamic flag corresponding to the printed coordinate point, it is necessary to execute a screening algorithm on the normalized Y coordinate. is the parameter set for embedding watermark, calculate ,in, The expression is as follows:

[0074] ;

[0075] if If it is true, the row is selected, the corresponding index is recorded, and a LSB-like (Least Significant Bit, a type of image steganography algorithm) extraction algorithm is performed on the normalized X coordinate. , at coordinates Perform bit extraction on the byte array. If the flag bit is even, the value at the corresponding index (i.e., the target bit value) is recorded as 0; if the flag bit is odd, the value at the corresponding index is recorded as 1.

[0076] Step S23: splicing the target bit values based on the target index values to obtain the binary bit stream, and obtaining the watermark character string based on the binary bit stream.

[0077] In this embodiment, it is necessary to splice each target bit value based on each target index value to obtain a binary bit stream. Specifically, in the same index identification set, 0 or 1 is selected according to the majority vote, and finally the bit is concatenated according to the index to obtain Finally, the watermark information is obtained through utf-8 encoding ; That is, the watermark extraction method in this embodiment supports blind extraction, and watermark extraction can be performed without the original carrier.

[0078] It can be seen that the present application improves the efficiency of processing watermarks in large-scale vector data by dynamically adjusting the watermark embedding ratio, and at the same time can control the number of affected points and reduce the error impact on the original carrier data; supports dynamic adjustment and modification of data points, is applicable to various precision data and has controllable precision; by constructing a dynamic parameter set and using the dynamic parameter set to determine the watermark addition range in the vector map spatial data, the watermark range can be adjusted, avoiding the use of a fixed watermark embedding ratio for data blind watermarking, thereby solving the problem of low efficiency in adding watermarks to large-scale vector geographic spatial data; by setting a dynamic flag and dynamically adjusting the watermark addition position according to the dynamic flag, the watermark addition position is random, thereby improving the applicability and anti-attack capability of the watermark.

[0079] See also Figure 5 As shown, the embodiment of the present invention discloses a blind watermarking device for vector geospatial data, comprising:

[0080] The data acquisition module 11 is used to acquire target vector geographic spatial data and select a target watermark embedding position corresponding to the target vector geographic spatial data;

[0081] a bit value determination module 12, configured to convert a preset watermark string into a binary bit stream using a target encoding method to obtain a string length corresponding to the preset watermark string, perform normalization processing on each original coordinate point corresponding to the target watermark embedding position to obtain a normalized coordinate point corresponding to each original coordinate point, and determine a target bit value corresponding to each normalized coordinate point based on the string length and a hash algorithm; wherein the target bit value is a bit value in the binary bit stream;

[0082] a flag setting module 13, configured to construct a target dynamic parameter set, filter a target coordinate point from each of the normalized coordinate points based on the target dynamic parameter set and the string length, and set a dynamic flag corresponding to the target coordinate point; wherein the target dynamic parameter set is used to determine a filtering range corresponding to the target coordinate point, and the dynamic flag is used to determine a target watermark embedding position, wherein the target watermark embedding position is any digit in the X coordinate of the original coordinate point;

[0083] The watermark embedding module 14 is used to embed a watermark on each of the target coordinate points based on the target bit value and the target watermark embedding position to obtain a corresponding printed coordinate point, and to denormalize each of the printed coordinate points to blindly watermark the target vector geospatial data; wherein the printed coordinate point is the coordinate point after the watermark is added.

[0084] It can be seen that the present application improves the efficiency of processing watermarks in large-scale vector data by dynamically adjusting the watermark embedding ratio, and at the same time can control the number of affected points and reduce the error impact on the original carrier data; supports dynamic adjustment and modification of data points, is applicable to various precision data and has controllable precision; by constructing a dynamic parameter set and using the dynamic parameter set to determine the watermark addition range in the vector map spatial data, the watermark range can be adjusted, avoiding the use of a fixed watermark embedding ratio for data blind watermarking, thereby solving the problem of low efficiency in adding watermarks to large-scale vector geographic spatial data; by setting a dynamic flag and dynamically adjusting the watermark addition position according to the dynamic flag, the watermark addition position is random, thereby improving the applicability and anti-attack capability of the watermark.

[0085] In some specific embodiments, the bit value determination module 12 may specifically include:

[0086] a coordinate value determining unit, configured to determine a maximum X coordinate value, a maximum Y coordinate value, a minimum X coordinate value, and a minimum Y coordinate value from each of the original coordinate points;

[0087] a first coordinate normalization unit, configured to obtain a first difference between an X coordinate of a current original coordinate point and the minimum X coordinate value, obtain a second difference between the maximum X coordinate value and the minimum X coordinate value, and normalize the X coordinate of the current original coordinate point based on the first difference and the second difference;

[0088] The second coordinate normalization unit is used to obtain a third difference between the Y coordinate of the current original coordinate point and the minimum Y coordinate value, obtain a fourth difference between the maximum Y coordinate value and the minimum Y coordinate value, and normalize the Y coordinate of the current original coordinate point based on the third difference and the fourth difference.

[0089] In some specific embodiments, the bit value determination module 12 may specifically include:

[0090] The bit value determination submodule is used to obtain the target index value corresponding to each normalized coordinate point based on the string length and the hash algorithm, and determine the target bit value corresponding to each normalized coordinate point according to each target index value.

[0091] In some specific embodiments, the bit value determination submodule may specifically include:

[0092] a coordinate integerization unit, configured to determine a target integerization parameter, and perform integerization processing on the Y coordinate of each normalized coordinate point according to the target integerization parameter to obtain a corresponding integerized Y coordinate; wherein the target integerization parameter is used to determine the number of digits of the integerized Y coordinate;

[0093] The first index value obtaining unit is configured to obtain the target index value corresponding to each of the normalized coordinate points according to the integerized Y coordinate, the character string length, and a hash algorithm.

[0094] In some specific embodiments, the watermark embedding module 14 may specifically include:

[0095] a first value modifying unit, configured to, if the target bit value is zero and the value to be modified corresponding to the target watermark embedding position is an odd number, add one to the value to be modified;

[0096] The second value modifying unit is configured to add one to the value to be modified if the target bit value is one and the value to be modified corresponding to the target watermark embedding position is an even number.

[0097] In some specific embodiments, the watermark embedding module 14 further includes:

[0098] A second index value acquisition unit is used to extract the printed coordinate points from the target vector geographic spatial data, and acquire the target index value corresponding to each printed coordinate point based on the character string length and a hash algorithm;

[0099] a bit value acquiring unit, configured to determine the dynamic flag corresponding to the printed coordinate point, and acquire the target bit value corresponding to each printed coordinate point based on the dynamic flag;

[0100] The character string obtaining unit is configured to concatenate the target bit values based on the target index values to obtain the binary bit stream, and obtain the preset watermark character string based on the binary bit stream.

[0101] Furthermore, the embodiment of the present application also discloses an electronic device, Figure 6 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content in the diagram should not be considered as any limitation to the scope of application of the present application.

[0102] Figure 6 This is a schematic diagram of the structure of an electronic device 20 provided in an embodiment of the present application. The electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps of the blind watermarking method for vector geospatial data disclosed in any of the aforementioned embodiments. Furthermore, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0103] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device. The communication protocol it follows is any communication protocol that can be applied to the technical solution of this application and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world. Its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0104] In addition, the memory 22 as a carrier for resource storage can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored thereon may include an operating system 221, a computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0105] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program that can be used to implement the vector geospatial data blind watermarking method performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include a computer program that can be used to implement other specific tasks.

[0106] Furthermore, this application also discloses a computer-readable storage medium for storing a computer program; wherein, when executed by a processor, the computer program implements the aforementioned blind watermarking method for vector geospatial data. The specific steps of this method can be referred to the corresponding contents disclosed in the aforementioned embodiments and will not be repeated here.

[0107] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the methods.

[0108] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0109] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0110] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0111] The above is a detailed introduction to the technical solution provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A blind watermarking method for vector geospatial data, characterized in that: include: Acquire target vector geospatial data, and select a target watermark embedding position corresponding to the target vector geospatial data; Converting a preset watermark character string into a binary bit stream using a target encoding method to obtain a character string length corresponding to the preset watermark character string, normalizing each original coordinate point corresponding to the target watermark embedding position to obtain a normalized coordinate point corresponding to each original coordinate point, and determining a target bit value corresponding to each normalized coordinate point based on the character string length and a hash algorithm; wherein the target bit value is a bit value in the binary bit stream; Constructing a target dynamic parameter set, filtering a target coordinate point from each of the normalized coordinate points based on the target dynamic parameter set and the string length, and setting a dynamic flag corresponding to the target coordinate point; wherein the target dynamic parameter set is used to determine a filtering range corresponding to the target coordinate point, and the dynamic flag is used to determine a target watermark embedding position, and the target watermark embedding position is any digit in the X coordinate of the original coordinate point; Based on the target bit value and the target watermark embedding position, each target coordinate point is watermarked to obtain a corresponding printed coordinate point, and each printed coordinate point is denormalized to blindly watermark the target vector geographic spatial data; wherein the printed coordinate point is the coordinate point after the watermark is added.

2. The vector geospatial data blind watermarking method according to claim 1, characterized in that: The normalizing of the original coordinate points corresponding to the target watermark embedding position includes: Determine the maximum X coordinate value, the maximum Y coordinate value, the minimum X coordinate value, and the minimum Y coordinate value from each of the original coordinate points; Obtaining a first difference between the X coordinate of the current original coordinate point and the minimum X coordinate value, obtaining a second difference between the maximum X coordinate value and the minimum X coordinate value, and normalizing the X coordinate of the current original coordinate point based on the first difference value and the second difference value; Obtain a third difference between the Y coordinate of the current original coordinate point and the minimum Y coordinate value, obtain a fourth difference between the maximum Y coordinate value and the minimum Y coordinate value, and normalize the Y coordinate of the current original coordinate point based on the third difference and the fourth difference.

3. The vector geospatial data blind watermarking method according to claim 1, characterized in that: The determining, based on the character string length and the hash algorithm, the target bit value corresponding to each of the normalized coordinate points includes: The target index values corresponding to the normalized coordinate points are obtained based on the character string length and the hash algorithm, and the target bit values corresponding to the normalized coordinate points are determined according to the target index values.

4. The vector geospatial data blind watermarking method according to claim 3, characterized in that: The obtaining of target index values corresponding to the normalized coordinate points based on the string length and the hash algorithm includes: Determining a target integer parameter, and performing integer processing on the Y coordinate of each of the normalized coordinate points according to the target integer parameter to obtain a corresponding integerized Y coordinate; wherein the target integer parameter is used to determine the number of digits of the integerized Y coordinate; The target index value corresponding to each of the normalized coordinate points is obtained according to the integer Y coordinate, the string length, and a hash algorithm.

5. The vector geospatial data blind watermarking method according to claim 1, characterized in that: The embedding of a watermark into each of the target coordinate points based on the target bit value and the target watermark embedding position includes: If the target bit value is zero and the value to be modified corresponding to the target watermark embedding position is an odd number, then adding one to the value to be modified; If the target bit value is one, and the value to be modified corresponding to the target watermark embedding position is an even number, an addition operation is performed on the value to be modified.

6. The vector geospatial data blind watermarking method according to claim 3, characterized in that: After denormalizing each of the printed coordinate points, the method further includes: Extracting the printed coordinate points from the target vector geographic spatial data, and obtaining the target index values corresponding to the printed coordinate points based on the character string length and a hash algorithm; Determine the dynamic flag corresponding to the printed coordinate point, and obtain the target bit value corresponding to each printed coordinate point based on the dynamic flag; The target bit values are concatenated based on the target index values to obtain the binary bit stream, and the preset watermark character string is obtained based on the binary bit stream.

7. A blind watermarking device for vector geospatial data, characterized in that: include: A data acquisition module is used to acquire target vector geographic spatial data and select a target watermark embedding position corresponding to the target vector geographic spatial data; a bit value determination module, configured to convert a preset watermark character string into a binary bit stream using a target encoding method to obtain a character string length corresponding to the preset watermark character string, perform normalization processing on each original coordinate point corresponding to the target watermark embedding position to obtain a normalized coordinate point corresponding to each of the original coordinate points, and determine a target bit value corresponding to each of the normalized coordinate points based on the character string length and a hash algorithm; wherein the target bit value is a bit value in the binary bit stream; a flag setting module, configured to construct a target dynamic parameter set, filter a target coordinate point from each of the normalized coordinate points based on the target dynamic parameter set and the string length, and set a dynamic flag corresponding to the target coordinate point; wherein the target dynamic parameter set is used to determine a filtering range corresponding to the target coordinate point, and the dynamic flag is used to determine a target watermark embedding position, wherein the target watermark embedding position is any digit in the X coordinate of the original coordinate point; A watermark embedding module is used to embed a watermark on each of the target coordinate points based on the target bit value and the target watermark embedding position to obtain a corresponding printed coordinate point, and to denormalize each of the printed coordinate points to blindly watermark the target vector geospatial data; wherein the printed coordinate point is the coordinate point after the watermark is added.

8. The vector geospatial data blind watermarking device according to claim 7, characterized in that: The bit value determination module includes: A bit value determination unit is used to obtain the target index value corresponding to each of the normalized coordinate points based on the character string length and the hash algorithm, and determine the target bit value corresponding to each of the normalized coordinate points according to each of the target index values.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the vector geospatial data blind watermarking method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that Used to store a computer program, which, when executed by a processor, implements the vector geospatial data blind watermarking method according to any one of claims 1 to 6.

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