A light shape point level vector high-precision map digital watermark generation method and system

Abstract

The application belongs to the technical field of map watermarking, and specifically provides a lightweight point-level vector high-precision map digital watermark generation method and system, wherein the method comprises the following steps: acquiring a high-precision map and spatial geographic coordinate information of elements needing to add digital watermark in the high-precision map, and projecting the high-precision map and the spatial geographic coordinate information to a plane coordinate system; acquiring a random secret key number s and the number n of element geographic coordinates, and generating a digital watermark sequence by using a digital watermark generation algorithm; and hiding and embedding the digital watermark sequence in the spatial geographic coordinate information under the control of a rule with controllable precision. The scheme can add digital watermark to all elements of a vector high-precision map, and can also add digital watermark to part of the elements; the digital watermark has controllable precision loss, which can effectively guarantee the quality of the vector high-precision map containing the digital watermark, and can generate part of the offset data for use as sample data; the digital watermark added to each shape point is random in a specific way and cannot be reproduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of map watermarking, and more particularly to a lightweight point-level vector high-precision map digital watermark generation method and system. BACKGROUND

[0002] High-precision maps are essential for high-level autonomous driving, which can provide intelligent vehicles with a lot of prior knowledge, such as vehicle positioning, road conditions, surrounding environment, unexpected events, and lane-level path planning. The copyright of vector high-precision maps is also becoming increasingly important, and ordinary watermarking technology is difficult to play a role in vector geospatial information.

[0003] There are currently three main methods for vector map watermarking:

[0004] The first is reversible watermarking algorithm. Reversible watermarking protects copyright by embedding watermark information in the original data. When extracting the watermark to verify the copyright, the original data can be restored after the watermark is extracted, thereby achieving zero interference of data. However, reversible watermarking technology has a significant drawback, that is, the watermark can only be used once because the reversible watermark information must be removed after extraction. Therefore, this method cannot meet the user's requirement for permanent watermarking. In addition, in order to satisfy the reversibility of the algorithm and the embedding space of the watermark at the same time, most reversible watermarks still need to obtain watermark hiding space by perturbing data precision. From this perspective, it is not truly lossless.

[0005] The second is lossless watermarking technology, which is zero watermarking. It generates watermark based on the characteristic information of vector maps without modifying the host data. The generated watermark will be stored in the IPR (intellectual property right) repository, and rely on third-party authority for watermark detection. The key of this method is to extract the stable characteristic information of the original vector map, and the zero watermark based on this characteristic information can resist various attacks. The characteristic information can be based on the spatial statistical characteristics or geometric characteristics of the vector map, and the characteristic information and the watermark information are further combined to generate zero watermark. Compared with reversible watermarking, zero watermarking achieves complete losslessness. However, it constructs watermark without embedding watermark, so there is a risk of false judgment when extracting and declaring copyright. For example, everyone can construct zero watermark based on the original data and register it to the intellectual property right agency they trust. In addition, the zero watermark mechanism needs to store watermark information in the third-party copyright agency, which has many limitations in practical application.

[0006] The third is a lossless watermarking method based on storage sequence. This method takes advantage of the ordered arrangement and unordered storage of vector maps, and hides watermark information in the storage rules of features. However, it cannot completely avoid the defects of reversible watermarking and zero watermarking, and the watermark will still disturb the coordinate information of the data, which cannot achieve complete losslessness.

[0007] The precision loss of the above watermarking methods is uncontrollable, and they do not have the function of detecting where the data is tampered with. SUMMARY

[0008] The present application aims at the technical problems of uncontrollable precision loss of existing watermarking methods and lack of function of detecting where the data is tampered with in the prior art.

[0009] The present application provides a light shape point level vector high-precision map digital watermark generation method, characterized by comprising the following steps:

[0010] S1, obtaining high-precision map and spatial geographic coordinate information of elements needing to add digital watermark, and projecting to a plane coordinate system;

[0011] S2, obtaining a random secret key number s∈(0,1) and the number of element geographic coordinates n, and generating a digital watermark sequence using a digital watermark generation algorithm;

[0012] S3, hiding and embedding the digital watermark sequence in the spatial geographic coordinate information under controllable precision rules.

[0013] Preferably, the S1 specifically comprises:

[0014] S101, obtaining vector high-precision map data and expressing it as a set of each entity element, the information of each entity element including element type, element id, spatial geographic coordinates, wherein the spatial geographic coordinates are a series of ordered shape points;

[0015] S102, projecting the spatial geographic coordinate information of the elements needing to add digital watermark to a rectangular coordinate.

[0016] Preferably, the S2 specifically comprises:

[0017] A first type of Chebyshev polynomial cos(m*arccos(s)) is used to batch generate a digital watermark sequence, wherein m is a random number randomly generated, and s is a random number randomly generated in the range of (0, 1).

[0018] Preferably, the S3 specifically comprises:

[0019] The digits after the decimal point of the coordinates (x, y, z) of the element geographic coordinates are rewritten and replaced according to a self-defined rule.

[0020] Preferably, the self-defined rule specifically comprises:

[0021] Randomly select a number in 1-9 to write in the 5th decimal place of z, write the numbers in the 6th-12th decimal places of z respectively according to the numbers in the 1st-7th decimal places of the number watermark, write the numbers in the 5th-9th decimal places of x respectively according to the numbers in the 8th-12th decimal places of the number watermark, and write the numbers in the 5th-8th decimal places of y respectively according to the numbers in the 13th-16th decimal places of the number watermark.

[0022] Preferably, the S3 further comprises S4 after the S3:

[0023] The digital watermark is detected and tamper detection is performed on the map according to the second type of Chebyshev polynomial Un.

[0024] Preferably, the S4 specifically comprises:

[0025] S401, according to the rule of embedding the digital watermark sequence, the digital watermark sequence S is inversely calculated;

[0026] S402, according to the secret key number s, e=S[n+1]-(2*s*S[n]-S[n-1]) is calculated, if e<1e-5 at each place, it is considered that the digital watermark is added by the above method, and the coordinate is probably not modified, if there is part e>1e-5, the place is tampered, wherein n is the number of element geographic coordinates.

[0027] The application also provides a light shape point level vector high-precision map digital watermark generation system, which is used for realizing the steps of the light shape point level vector high-precision map digital watermark generation method, and specifically comprises:

[0028] A map acquisition module is used for acquiring a high-precision map and spatial geographic coordinate information of elements needing to add digital watermarks, and projecting the information into a plane coordinate system.

[0029] A digital watermark production module is used for acquiring a random secret key number s∈(0, 1) and the number n of element geographic coordinates, and generating a digital watermark sequence by using a digital watermark generation algorithm.

[0030] A watermark embedding module is used for hiding and embedding the digital watermark sequence into the spatial geographic coordinate information under the rule of controllable precision.

[0031] The application also provides an electronic device comprising a memory and a processor, wherein the processor is used for executing a computer management type program stored in the memory to realize the steps of the light shape point level vector high-precision map digital watermark generation method.

[0032] The application also provides a computer readable storage medium, wherein a computer management type program is stored on the computer readable storage medium, and the computer management type program is executed by a processor to realize the steps of the light shape point level vector high-precision map digital watermark generation method.

[0033] Beneficial effects: the lightweight shape point level vector high-precision map digital watermark generation method and system provided by the application, wherein the method comprises the following steps: acquiring a high-precision map and spatial geographic coordinate information of elements needing to add digital watermark in the high-precision map, and projecting the high-precision map and the spatial geographic coordinate information to a plane coordinate system; acquiring a random secret key number s∈(0, 1) and the number n of element geographic coordinates, and generating a digital watermark sequence by using a digital watermark generation algorithm; and hiding and embedding the digital watermark sequence in the spatial geographic coordinate information under the control of a precision rule. The scheme can add digital watermark to all elements of a vector high-precision map, and can also add digital watermark to part of the elements; and the digital watermark has controllable precision loss, which can effectively ensure the quality of the vector high-precision map containing the digital watermark, and can generate part of the offset data as sample data; the digital watermark added to each shape point is random in a specific way and cannot be reproduced; and the digital watermark has the function of detecting the place where the data is tampered with. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A lightweight shape point level vector high-precision map digital watermark generation method flowchart is provided for the application;

[0035] Figure 2 A hardware structure schematic diagram of a possible electronic device is provided for the application;

[0036] Figure 3 A hardware structure schematic diagram of a possible computer readable storage medium is provided for the application;

[0037] Figure 4 An original curved line element graph is provided for the application;

[0038] Figure 5 A graph of a curved line element after watermarking is provided for the application. DETAILED DESCRIPTION

[0039] The specific embodiments of the application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the application, but are not used to limit the scope of the application.

[0040] Reference Figure 1 , Figure 4 and Figure 5 , the application embodiment provides a lightweight shape point level vector high-precision map digital watermark generation method, comprising the following steps:

[0041] S1, acquiring a high-precision map and spatial geographic coordinate information of elements needing to add digital watermark in the high-precision map, and projecting the high-precision map and the spatial geographic coordinate information to a plane coordinate system; all elements of the vector high-precision map include shape points such as lane lines, POI, road network and elements with a shape point number>3.

[0042] S2, obtain a random secret key number s∈(0, 1) and the number n of element geographic coordinates, and generate a digital watermark sequence by using a digital watermark generation algorithm; the digital watermark can be added to all elements or part of the elements. The secret key number s is obtained by using a random algorithm. One element geographic coordinate corresponds to one shape point, so the digital watermark added to each shape point is random in a specific way, that is, it is not reproducible.

[0043] S3, hide and embed the digital watermark sequence in the spatial geographic coordinate information under controllable precision.

[0044] The technical scheme of the embodiment provides a lightweight shape point level, strong randomness, and a controllable precision loss digital watermark generation and verification method, and has the function of detecting the place where the data is tampered with.

[0045] In a further scheme, first, the spatial geographic coordinate information of the elements to which the digital watermark needs to be added in the high-precision map is projected into a plane coordinate system, and then watermark information is generated by using a digital watermark generation algorithm according to a self-defined secret key number s∈(0, 1) and the number of element geographic coordinates. It is noted that the randomness in the generation algorithm process, the generated digital watermark information is random in [0, 1] and cannot be calculated inversely. Then, the digital watermark information is hidden and embedded into the spatial geographic coordinate information under controllable precision.

[0046] In a preferred scheme, S2 specifically includes: using a first type of Chebyshev polynomial cos(m*arccos(s)) to batch generate a digital watermark sequence, wherein m is a random number randomly generated, and s is a random number randomly generated in the range of (0, 1). The first type of Chebyshev polynomial T n (x)=cos(n*arccos(x)) is an n-th Chebyshev polynomial, wherein x∈[-1,1], Its recursive property can be expressed as:

[0047] T0(x)=1,T1(x)=x,

[0048] T n+1 (x)=2nT n (x)-T n-1 (x)。

[0049] The digital watermark production algorithm in the computer is as follows:

[0050] Input: number of geographic coordinate shape points (number of element geographic coordinates) n, self-defined secret key number s∈(0, 1), and randomly generated integer m.

[0051] a=[]

[0052] for i = 0, 1,..., l-1 do

[0053] m = m + i

[0054] t = cos(m*arccos(s))

[0055] a.append(t)

[0056] end for

[0057] Output: digital watermark a

[0058] Specifically, the generation of the Chebyshev polynomial digital watermark is as follows: first, vector high-precision map data is obtained, which can be expressed as a set of various elements, and each entity element information includes element type, element id, spatial geographic coordinates, etc., wherein the spatial geographic coordinates are a series of ordered shape points such as [(x1, y1, z1), (x2, y2, z2),..., (x n , y n , z n )].

[0059] Further, the S3 specifically includes: rewriting and replacing the digits after the decimal point of the element geographic coordinates (x, y, z) according to a self-defined rule.

[0060] Specifically, according to the precision loss requirement, the digital watermark sequence is hidden and written into the corresponding shape point coordinates in a specific method, and a self-defined rule algorithm can be used here. The method given in this embodiment is to rewrite the digits after the decimal point of the coordinates (x, y, z). A simple real example is shown in the attached Figure 1 , wherein the digits after the decimal point are rewritten from the fourth digit, and '0' represents a negative sign to write the fifth digit after the decimal point of z. If it is a positive number, a number from 1 to 9 can be randomly selected and written, because the digital watermark sequence is in (0, 1), '0.' can not be represented, the digits after the decimal point of the digital watermark from 1 to 7 are written into the 6th to 12th digits after the decimal point of z, the digits after the decimal point of the digital watermark from 8 to 12 are written into the 5th to 9th digits after the decimal point of x, the digits after the decimal point of the digital watermark from 13 to 16 are written into the 5th to 8th digits after the decimal point of y, and the precision error d(p, p') is less than 0.00018m, which far satisfies the demand of high-precision map.

[0061] Further, the scheme S3 further comprises S4: according to the second Chebyshev polynomial Un as digital watermark detection and tamper detection. Namely, according to the second expression form (recursive form) of the Chebyshev polynomial as digital watermark detection and tamper detection.

[0062] Specifically, first, the geographic coordinate information of the elements is acquired according to the vector high-precision map with digital watermark, the digital watermark sequence S is calculated according to the rule of digital watermark embedding, then e=S[n+1]-(2*s*S[n]-S[n-1]) is calculated according to the secret key number s, if e<1e-5 at each place, it is considered that the digital watermark is added by the above method, and the coordinate is probably not modified, if there is part e>1e-5, then the nearby place is probably tampered.

[0063] The embodiment of the present application also provides a light shape point-level vector high-precision map digital watermark generation system, which is used for realizing the steps of the light shape point-level vector high-precision map digital watermark generation method, and specifically comprises:

[0064] A map acquisition module is used for acquiring the high-precision map and the spatial geographic coordinate information of the elements needing to add digital watermark, and projecting to a plane coordinate system.

[0065] A digital watermark production module is used for acquiring a random secret key number s∈(0,1) and the number n of the element geographic coordinates, and generating a digital watermark sequence by using a digital watermark generation algorithm.

[0066] A watermark embedding module is used for hiding and embedding the digital watermark sequence into the spatial geographic coordinate information under the rule of controllable precision.

[0067] Please refer to Figure 2 An embodiment example of an electronic device provided by the embodiment of the present application is shown in the figure. Figure 2 As shown in the figure, the embodiment of the present application provides an electronic device, which comprises a memory 1310, a processor 1320, and a computer program 1311 stored in the memory 1310 and capable of running on the processor 1320, and the processor 1320 realizes the following steps when executing the computer program 1311: S1, acquiring the high-precision map and the spatial geographic coordinate information of the elements needing to add digital watermark, and projecting to a plane coordinate system.

[0068] S2, acquiring a random secret key number s∈(0,1) and the number n of the element geographic coordinates, and generating a digital watermark sequence by using a digital watermark generation algorithm.

[0069] S3, hiding and embedding the digital watermark sequence into the spatial geographic coordinate information under the rule of controllable precision.

[0070] Please refer to Figure 3 An embodiment of a computer readable storage medium provided by the present application is shown. As shown in the figure, the embodiment provides a computer readable storage medium 1400, which stores a computer program 1411, and the computer program 1411 is executed by a processor to implement the following steps: S1, obtaining a high-precision map and spatial geographic coordinate information in which a digital watermark element needs to be added, and projecting the information into a plane coordinate system; Figure 3

[0071] S2, obtaining a random secret key number s∈(0, 1) and the number of element geographic coordinates n, and generating a digital watermark sequence by using a digital watermark generation algorithm;

[0072] S3, hiding and embedding the digital watermark sequence in the spatial geographic coordinate information under the control of the precision.

[0073] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0074] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0075] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.​

Claims

1. A method for generating a digital watermark for a high-precision map at a point level with light weight shape vectors, characterized by, The method comprises the following steps: S1, obtaining high-precision map and spatial geographic coordinate information of elements needing to add digital watermark, and projecting to a plane coordinate system; S2, obtaining a random key number and the number of element geographic coordinates n, generating a digital watermark sequence by using a digital watermark generation algorithm; S3, hiding and embedding the digital watermark sequence in the spatial geographic coordinate information under controllable precision rules; The S2 specifically comprises: The first Chebyshev polynomial cos(m ) batch generates a digital watermark sequence, wherein m is a random number randomly generated, and s is a random number randomly generated in the range of (0, 1). The S3 specifically comprises: The digits after the decimal point of the coordinate (x, y, z) of the element geographic coordinate are rewritten and replaced according to the self-defined rules; The self-defined rules specifically comprise: A number is randomly selected from 1-9 and written to the 5th digit after the decimal point of z, the digits 1-7 after the decimal point of the digital watermark are respectively written to the 6th-12th digits after the decimal point of z, the digits 8-12 after the decimal point of the digital watermark are respectively written to the 5th-9th digits after the decimal point of x, and the digits 13-16 after the decimal point of the digital watermark are respectively written to the 5th-8th digits after the decimal point of y.

2. The method of claim 1, wherein The S1 specifically comprises: S101, obtaining vector high-precision map data, and expressing as a set of each entity element, the information of each entity element comprising an element type, an element id, and a spatial geographic coordinate, wherein the spatial geographic coordinate is a series of ordered shape points; S102, projecting the spatial geographic coordinate information of the elements needing to add digital watermark to a rectangular coordinate.

3. The method of claim 1, wherein the method is a method of generating a digital watermark for a light-weight shape point-level vector high-precision map, characterized by, The S3 further comprises S4: According to the second type of Chebyshev polynomial Un, the map is detected for digital watermark and tampering.

4. The method of claim 3, wherein the method further comprises: The S4 specifically comprises: S401, according to the rule when the digital watermark sequence is embedded, the digital watermark sequence S is inversely calculated; S402, according to the key number calculating ), if each place <1×10 -5 , the digital watermark is added by the above method, and the coordinates are not modified, if there are some positions > 1×10 -5 , the part position is tampered, wherein n is the number of element geographic coordinates.

5. A lightweight point-level vector high-precision map digital watermark generation system, characterized in that, The system is used to realize the steps of the lightweight shape point level vector high-precision map digital watermark generation method according to any one of claims 1-4, and specifically comprises: A map acquisition module is configured to obtain high-precision map and spatial geographic coordinate information of elements needing to add digital watermark, and project to a plane coordinate system; A digital watermark production module is configured to obtain a random secret key number and the number n of geographical coordinates of the element, a digital watermark sequence is generated by using a digital watermark generation algorithm. A watermark embedding module is configured to hide and embed a digital watermark sequence in the spatial geographic coordinate information under controllable precision rules; The digital watermark production module is specifically configured to: The first Chebyshev polynomial cos(m ) is used to generate a batch of digital watermark sequences, wherein m is a random number, and s is a random number generated in the range of (0, 1). The watermark embedding module is specifically configured to: The digits after the decimal point of the coordinate (x, y, z) of the element geographic coordinate are rewritten and replaced according to the self-defined rules; The self-defined rules specifically comprise: A number is randomly selected from 1-9 and written to the 5th digit after the decimal point of z, the digits 1-7 after the decimal point of the digital watermark are respectively written to the 6th-12th digits after the decimal point of z, the digits 8-12 after the decimal point of the digital watermark are respectively written to the 5th-9th digits after the decimal point of x, and the digits 13-16 after the decimal point of the digital watermark are respectively written to the 5th-8th digits after the decimal point of y.

6. An electronic device, comprising: The system comprises a memory and a processor, and the processor is used to execute a computer management program stored in the memory to realize the steps of the lightweight shape point level vector high-precision map digital watermark generation method according to any one of claims 1-4.

7. A computer-readable storage medium, characterized in that, A computer management program is stored on the memory, and the computer management program is executed by the processor to realize the steps of the lightweight shape point level vector high-precision map digital watermark generation method according to any one of claims 1-4.

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