Multispectral image encryption method and device, equipment and medium

Abstract

The invention discloses a multispectral image encryption method and device, equipment and a medium, and relates to the technical field of image encryption, and the method comprises the steps: generating a composite chaotic sequence through employing Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping, carrying out the encryption of an original multispectral image based on the composite chaotic sequence, and obtaining an encrypted multispectral image. According to the image encryption method and device, the problems that an existing image encryption algorithm adopting a single chaotic system is low in safety and poor in attack resistance are solved, and the safety and the attack resistance are improved.

Description

Technical Field

[0001] The present application relates to the field of image encryption technology, and in particular to a multispectral image encryption method, device, equipment and medium. Background Art

[0002] Remote sensing technology began in the 1960s. It is a comprehensive technology that uses various sensors to identify and detect various scenes on the ground. It was formed on the basis of aerial photography with the development of aerospace technology and electronics technology. Remote sensing technology uses sensors installed on artificial satellites or other aircraft to work on the electromagnetic radiation characteristics of targets of interest on land and in the ocean. The remote sensing system consists of the following parts: information source, remote sensor (space camera, multispectral scanner, synthetic aperture radar, etc.), remote sensing platform (aircraft, satellite, etc.), information transmission and receiving equipment, information processing equipment, etc. The information transmission equipment is the carrier for transmission between remote sensing platforms such as satellites and aircraft and the ground. The information processing equipment performs a series of effective processing such as filtering and geometric correction on the remote sensing information received on the ground to obtain clear and useful information such as properties and status. While providing more detailed spectral information about the ground objects, the amount of data in the space multispectral image increases sharply, which brings difficulties to the transmission and storage of airborne and satellite data. In addition, since some reconnaissance and surveillance work does not want to be cracked by other countries or organizations, in addition to communication link encryption, it is very necessary to encrypt multispectral images to ensure data security.

[0003] Existing encryption algorithms have deficiencies in key space and key sensitivity, and have problems such as low security and poor anti-attack performance. Therefore, a multispectral image encryption method with high security and strong anti-attack performance is urgently needed. Summary of the invention

[0004] The purpose of this application is to provide a multispectral image encryption method, device, equipment and medium, which can improve security and anti-attack capabilities.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a multispectral image encryption method, comprising:

[0007] The composite chaotic sequence is generated by using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping;

[0008] Based on the composite chaotic sequence, the original multispectral image is encrypted to obtain the encrypted image corresponding to the original multispectral image.

[0009] In a second aspect, the present application provides a multispectral image encryption device, comprising:

[0010] A compound chaotic sequence generation module is used to generate a compound chaotic sequence using a Logistic chaotic map and a two-dimensional sine-cosine chaotic map;

[0011] The image encryption module is used to encrypt the original multispectral image based on the composite chaotic sequence to obtain the encrypted image corresponding to the original multispectral image.

[0012] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned multispectral image encryption method.

[0013] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the above-mentioned multispectral image encryption method when executed by a processor.

[0014] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0015] The present application provides a multispectral image encryption method, apparatus, device and medium, which utilizes Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping to generate a composite chaotic sequence, and based on the composite chaotic sequence, encrypts the original multispectral image to obtain an encrypted image corresponding to the original multispectral image, thereby solving the problems of low security and poor anti-attack performance of existing image encryption algorithms using a single chaotic system, and improving security and anti-attack performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is an application environment diagram of a multi-spectral image encryption method in an embodiment of the present application;

[0018] Figure 2 A schematic diagram of a multispectral image encryption method provided in one embodiment of the present application;

[0019] Figure 3 A schematic diagram of a detailed process of a multispectral image encryption method provided in one embodiment of the present application;

[0020] Figure 4 A schematic diagram of functional modules of a multispectral image encryption device provided in one embodiment of the present application;

[0021] Figure 5 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0024] The multispectral image encryption method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the original multispectral image to the server 104. After the server 104 receives the original multispectral image, it uses the Logistic chaotic map and the two-dimensional sine-cosine chaotic map to generate a composite chaotic sequence according to the set initial value. Based on the composite chaotic sequence, the original multispectral image is encrypted to obtain the encrypted image corresponding to the original multispectral image. The server 104 can feed back the encrypted image corresponding to the obtained original multispectral image to the terminal 102. In addition, in some embodiments, the multispectral image encryption method can also be implemented by the server 104 or the terminal 102 alone, such as the terminal 102 can directly encrypt the original multispectral image, or the server 104 can obtain the original multispectral image from the data storage system and encrypt the original multispectral image.

[0025] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones, and tablet computers. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0026] In an exemplary embodiment, Figure 2 As shown, a multispectral image encryption method is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1The server 104 in the example is used as an example to illustrate, including the following steps 201 to 202. Among them:

[0027] Step 201: Generate a composite chaotic sequence using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping.

[0028] Step 202: Encrypt the original multispectral image based on the composite chaotic sequence to obtain an encrypted image corresponding to the original multispectral image.

[0029] The implementation of the above steps 201 to 202 solves the problem of low security and poor anti-attack performance of the existing image encryption algorithm using a single chaotic system, thereby improving security and anti-attack performance.

[0030] The generation process of the composite chaotic sequence specifically includes the following steps:

[0031] 1) Using the Logistic chaotic map, a Logistic chaotic sequence is iteratively generated according to the first set initial value;

[0032] 2) taking the iteration values ​​corresponding to the first set iteration number and the second set iteration number from the Logistic chaotic sequence as the second set initial value of the two-dimensional sine-cosine chaotic mapping, and iteratively generating a two-dimensional sine-cosine chaotic sequence;

[0033] 3) removing the first set number of iteration values ​​in the two-dimensional sine-cosine chaotic sequence to obtain an intermediate chaotic sequence;

[0034] 4) A sequence of a set length is intercepted from the intermediate chaotic sequence by using a key, and the intercepted sequence of the set length is determined as a composite chaotic sequence; the set length is twice the number of pixels of the high-frequency image or the low-frequency image.

[0035] The present application proposes a chaotic system combining a Logistic chaotic mapping and a two-dimensional sine-cosine chaotic mapping. The two chaotic systems are used in combination, and the composite chaotic system is used to perform two rounds of diffusion and scrambling processing on the image.

[0036] The Logistic chaotic map is shown as follows:

[0037] x i+1 =4μx i (1-x i ) (1);

[0038] Among them, x i+1 is the i+1th iteration value in the Logistic chaotic map, x iis the i-th iteration value in the Logistic chaotic mapping, μ is the control parameter of the Logistic chaotic mapping, μ∈(0, 1]. When the parameter μ∈[0.89, 1], the system is in a chaotic state.

[0039] The two-dimensional sine-cosine chaotic mapping overcomes the shortcomings of the one-dimensional chaotic system, such as narrow chaotic interval and simple structure. The chaotic system has better randomness and ergodicity, and has a wider hyperchaotic range. It is suitable for image encryption. Its expression is shown in the following formula:

[0040]

[0041] Among them, (x i+1 ,y i+1 ) is the i+1th iteration value in the two-dimensional sine-cosine chaotic mapping, (x i ,y i ) is the i-th iteration value in the two-dimensional sine-cosine chaotic mapping, α and β are the control parameters of the two-dimensional sine-cosine chaotic mapping, and both are not 0; the final output signals x and y are in the range of [-1,1]. For each multi-spectral spectrum of size M×N, two columns of length M×N chaotic sequences need to be generated, that is, for each high-frequency image or low-frequency image, the length (set length) of the final composite chaotic sequence is twice the number of pixels of the high-frequency image or low-frequency image.

[0042] There is overlap in the value range between the Logistic chaotic map and the two-dimensional sine-cosine chaotic map. In order to increase the randomness of the chaotic system, the present application introduces the Logistic chaotic map to generate the initial value of the two-dimensional sine-cosine chaotic map. Specifically, the values ​​of the Kth (K is the first set number of iterations) and K+M×N (K+M×N is the second set number of iterations) iterations of the Logistic chaotic sequence are taken as the initial values ​​of the two-dimensional sine-cosine chaotic sequence. The two-dimensional sine-cosine chaotic sequence is iteratively generated by giving the values ​​of the control coefficients α and β. In order to avoid the single value and periodicity of the chaotic system, the first 10,000 points of the two-dimensional sine-cosine chaotic sequence are discarded to obtain an intermediate chaotic sequence, and the intermediate chaotic sequence with a length of M×N is intercepted by a key as a composite chaotic sequence. Through the above processing, the randomness of the sequence is improved, and the final result is related to the size of the image, which improves the security of the algorithm.

[0043] The key generation process is as follows: for a multispectral image with n spectral bands, n keys are required, that is, each high-frequency image or each low-frequency image corresponds to a key, and the key can be generated by the following formula:

[0044]

[0045] In the formula, Kn is the key corresponding to the nth spectrum segment, abs() means taking the absolute value, ceil() means rounding up, M×N is the length of the chaotic sequence, and δ is the calculation accuracy. The generation of each key depends on the composite chaotic sequence generated in the previous step, which can enhance the randomness of the key.

[0046] In another exemplary embodiment of the present application, Figure 3 As shown, the above step 202 is replaced by the following steps 301 to 303:

[0047] Step 301: Divide the original multispectral image into spectral segments to obtain a number of high-frequency images and a number of low-frequency images.

[0048] Step 302: For each high-frequency image, encrypt the high-frequency image using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the high-frequency image.

[0049] Step 303: For each low-frequency image, encrypt the low-frequency image using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the low-frequency image; the encrypted sub-images corresponding to all high-frequency images and the encrypted sub-images corresponding to all low-frequency images constitute the encrypted image corresponding to the original multispectral image.

[0050] The present application utilizes Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping to perform different diffusion and scrambling processing on the generated low-frequency images and high-frequency images.

[0051] Wherein, in step 302, the high-frequency image is encrypted using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the high-frequency image, which specifically includes steps 401 to 404:

[0052] Step 401: using a first composite chaotic sequence as row coordinates and column coordinates of the high-frequency image, spatially scrambling the high-frequency image to obtain a scrambled high-frequency image; the first composite chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a first initial value;

[0053] Step 402: using a second composite chaotic sequence to encrypt the scrambled high-frequency image to obtain a first intermediate encrypted image corresponding to the high-frequency image; the second composite chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a second initial value;

[0054] Step 403: using a third composite chaotic sequence to encrypt the first intermediate encrypted image, to obtain a second intermediate encrypted image corresponding to the high-frequency image; the third composite chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a third initial value; the third initial value is a normalized pixel mean; the normalized pixel mean is obtained by calculating the mean grayscale value of all pixels of the first intermediate encrypted image corresponding to the high-frequency image;

[0055] Step 404: Replace the high-frequency image with the second intermediate encrypted image, and repeat steps 401 to 403 to obtain an encrypted sub-image corresponding to the high-frequency image.

[0056] Step 403 specifically includes:

[0057] Expanding the pixel matrix corresponding to the first intermediate encrypted image into one-dimensional sequence data;

[0058] The one-dimensional sequence data is encrypted using the third composite chaotic sequence to obtain a second intermediate encrypted image corresponding to the high-frequency image.

[0059] The first few spectral segments with relatively concentrated energy are high-frequency images. For each high-frequency image, a two-round encryption diffusion strategy is adopted. Each round of encryption diffusion process includes steps 401 to 406, that is, each round of encryption diffusion process includes spatial scrambling processing, initial encryption and diffusion encryption processing. Specifically: given the initial value of the composite chaotic sequence and the initial value of the control parameter, iterate a certain number of times, and use the generated discrete sequence (the first composite chaotic sequence) as the row and column coordinates of the high-frequency image to achieve spatial scrambling of the high-frequency image. Then use the second composite chaotic sequence to encrypt the scrambled image. The initial encryption step is shown in the following formula.

[0060]

[0061] Where Q and Q' represent the scrambled high-frequency image and the first intermediate encrypted image, respectively, and X i1 and Y i1 Constitute the second composite chaotic sequence, X i1 represents the pixel horizontal coordinate matrix in the second composite chaotic sequence, Y i1 represents the pixel ordinate matrix in the second composite chaotic sequence, and X i1 and Y i1 The corresponding inverse sequence matrix is, Represents the exclusive-or operation.

[0062] In order to make the image data more resistant to attacks, the encrypted data needs to be further diffused and encrypted. The normalized pixel mean is used as the initial value x0 of the composite chaotic sequence. At the same time, the initial value y0 and other control parameters (μ, α and β) are given. After a certain number of iterations, the third composite chaotic sequence (diffusion sequence) is generated. Q' is expanded into 1D sequence data along the column direction, and the first intermediate encrypted image corresponding to the high-frequency image is encrypted based on the third composite chaotic sequence. The diffusion encryption processing formula is shown in the following formula (5).

[0063]

[0064] Where G represents the second intermediate encrypted image corresponding to the high-frequency image, X i2 and Y i2 Constitute the second composite chaotic sequence, X i2 represents the pixel horizontal coordinate matrix in the second composite chaotic sequence, Y i2 represents the pixel ordinate matrix in the second composite chaotic sequence, and X i2 and Y i2 The corresponding inverse sequence matrix.

[0065] Through the above steps, the first round of encryption of the high-frequency image data is completed. The second round of encryption can be performed through similar operations, that is, the high-frequency image in step 402 is replaced by the second intermediate encrypted image corresponding to the high-frequency image, and the second intermediate encrypted image G corresponding to the high-frequency image is subjected to spatial scrambling processing. Then, the scrambled second intermediate encrypted image is subjected to initial encryption and diffusion encryption processing in sequence through formulas (4) and (5), which will not be repeated here.

[0066] In step 303, the low-frequency image is encrypted using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the low-frequency image, which specifically includes the following steps 501 to 502:

[0067] Step 501: using a fourth compound chaotic sequence to perform spatial scrambling on the low-frequency image to obtain a scrambled low-frequency image; the fourth compound chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a fourth initial value.

[0068] Step 502: Perform Arnold transformation on the scrambled low-frequency image to obtain an encrypted sub-image corresponding to the low-frequency image.

[0069] To improve the efficiency of the algorithm, other spectrum segments with lower energy, i.e., low-frequency images, are used in this application to encrypt low-frequency images using different strategies for each low-frequency image. Using different strategies will also increase the difficulty of cracking. Image scrambling does not change the pixel value of the image, so it cannot change the statistical characteristics of the original image, but it can better improve the visual effect of the encrypted image. To enhance the anti-attack ability of the algorithm, this application performs spatial scrambling on the low-frequency image through the fourth composite chaotic sequence, and then performs an improved Arnold transform on the scrambled low-frequency image.

[0070] The generalized Arnold transform has the following form:

[0071]

[0072] Wherein, k is the number of iterations, N is the size of the low-frequency image, A is the initial parameter matrix, a is the initial parameter, b is the initial parameter (when a=b=1, the transformation is the narrow Arnold transformation), (x, y) is the pixel value before the transformation, and (x', y') is the pixel value after the transformation.

[0073] This application expands the low-frequency image into a one-dimensional vector and normalizes the grayscale value of the pixel in the low-frequency image to the range of [0, 255]. In order to improve the key sensitivity of the algorithm and the key space of the algorithm, this application introduces the key into the Arnold transform. The improved Arnold transform form is shown in formula (7).

[0074]

[0075] The present application can also restore the scrambled image through inverse transformation, and the inverse transformation form is shown in formula (8).

[0076]

[0077] The information entropy of the multispectral image encryption method provided by the present application is 11.8671, which is closer to the ideal value and has better anti-attack performance. The ideal values ​​of the number of pixels change rate (NPCR) and the normalized average changing intensity (UACI) are 100% and 34.46% respectively. The NPCR and UACI of the multispectral image encryption method provided by the present application are closer to the ideal values, which are 99.85% and 34.22% respectively. Therefore, compared with the existing encryption algorithms, the multispectral image encryption method provided by the present application can better resist differential attacks.

[0078] Keep the key unchanged, randomly change a pixel value in the multispectral image, and evaluate the sensitivity of the multispectral image encryption method provided by this application to plaintext through the change of the encrypted bit stream. 100 simulation experiments were conducted on QuickBird satellite impact data with specific compression ratios with different characteristics. It can be seen from the experiment that the ciphertext bit stream change rate is maintained at 47.46%-47.52%. It can be seen that the multispectral image encryption method provided by this application is very sensitive to plaintext images and can effectively resist differential attacks.

[0079] The present application also provides an application scenario, which applies the above-mentioned multispectral image encryption method. Specifically: the multispectral image encryption method provided in this embodiment can be applied in the image encryption scenario. The image encryption scenario includes an image acquisition link and an image encryption link; the original multispectral image enters the image encryption link from the image acquisition link to obtain the corresponding encrypted image. The multispectral image encryption method provided in this embodiment belongs to the image encryption link. Specifically, in the image encryption link process for the original multispectral image, a composite chaotic sequence can be generated according to the set initial value using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping, and the original multispectral image is encrypted based on the composite chaotic sequence to obtain the encrypted image corresponding to the original multispectral image.

[0080] Based on the same inventive concept, the embodiment of the present application also provides a multispectral image encryption device for implementing the multispectral image encryption method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more multispectral image encryption device embodiments provided below can refer to the limitations of the multispectral image encryption method above, and will not be repeated here.

[0081] In an exemplary embodiment, Figure 4 As shown, a multi-spectral image encryption device is provided, comprising:

[0082] The composite chaotic sequence generation module T1 is used to generate a composite chaotic sequence by using a Logistic chaotic map and a two-dimensional sine-cosine chaotic map;

[0083] The image encryption module T2 is used to encrypt the original multispectral image based on the composite chaotic sequence to obtain an encrypted image corresponding to the original multispectral image.

[0084] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 5As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store image encryption processing data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a multispectral image encryption method is implemented.

[0085] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0086] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0087] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0088] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0089] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0090] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0091] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A multispectral image encryption method, characterized in that: The multispectral image encryption method comprises: The composite chaotic sequence is generated by using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping; Based on the composite chaotic sequence, the original multispectral image is encrypted to obtain the encrypted image corresponding to the original multispectral image.

2. The multispectral image encryption method according to claim 1, characterized in that: Based on the composite chaotic sequence, the original multispectral image is encrypted to obtain the encrypted image corresponding to the original multispectral image, which specifically includes: Divide the original multispectral image into spectral segments to obtain several high-frequency images and several low-frequency images; For each high-frequency image, encrypt the high-frequency image using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the high-frequency image; For each low-frequency image, the low-frequency image is encrypted using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the low-frequency image; the encrypted sub-images corresponding to all high-frequency images and the encrypted sub-images corresponding to all low-frequency images constitute the encrypted image corresponding to the original multispectral image.

3. The multispectral image encryption method according to claim 2, characterized in that: Encrypting the high-frequency image by using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the high-frequency image specifically includes: Step 401: using a first composite chaotic sequence as row coordinates and column coordinates of the high-frequency image, spatially scrambling the high-frequency image to obtain a scrambled high-frequency image; the first composite chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a first initial value; Step 402: using a second composite chaotic sequence to encrypt the scrambled high-frequency image to obtain a first intermediate encrypted image corresponding to the high-frequency image; the second composite chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a second initial value; Step 403: using a third composite chaotic sequence to encrypt the first intermediate encrypted image, to obtain a second intermediate encrypted image corresponding to the high-frequency image; the third composite chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a third initial value; the third initial value is a normalized pixel mean; the normalized pixel mean is obtained by calculating the mean grayscale value of all pixels of the first intermediate encrypted image corresponding to the high-frequency image; Step 404: Replace the high-frequency image with the second intermediate encrypted image, and repeat steps 401 to 403 to obtain an encrypted sub-image corresponding to the high-frequency image.

4. The multispectral image encryption method according to claim 2, characterized in that: Encrypting the low-frequency image by using a composite chaotic sequence to obtain an encrypted sub-image corresponding to the low-frequency image specifically includes: Using a fourth compound chaotic sequence, spatially scrambling the low-frequency image to obtain a scrambled low-frequency image; the fourth compound chaotic sequence is generated by a Logistic chaotic map and a two-dimensional sine-cosine chaotic map based on a fourth initial value; Perform Arnold transformation on the scrambled low-frequency image to obtain an encrypted sub-image corresponding to the low-frequency image.

5. The multispectral image encryption method according to claim 2, characterized in that: The generation process of the composite chaotic sequence includes: Using the Logistic chaotic map, a Logistic chaotic sequence is iteratively generated according to the first set initial value; The iterative values ​​corresponding to the first set number of iterations and the second set number of iterations are taken from the Logistic chaotic sequence as the second set initial value of the two-dimensional sine-cosine chaotic mapping, and the two-dimensional sine-cosine chaotic sequence is iteratively generated; The first set number of iteration values ​​in the two-dimensional sine-cosine chaotic sequence are removed to obtain an intermediate chaotic sequence; A sequence of a set length is intercepted from the intermediate chaotic sequence, and the intercepted sequence of the set length is determined as a composite chaotic sequence; the set length is twice the number of pixels of the high-frequency image or the low-frequency image.

6. The multispectral image encryption method according to claim 3, characterized in that: The first intermediate encrypted image is encrypted by using the third composite chaotic sequence to obtain a second intermediate encrypted image corresponding to the high-frequency image, specifically including: Expanding the pixel matrix corresponding to the first intermediate encrypted image into one-dimensional sequence data; The one-dimensional sequence data is encrypted using the third composite chaotic sequence to obtain a second intermediate encrypted image corresponding to the high-frequency image.

7. A multispectral image encryption device, characterized in that: The multispectral image encryption device comprises: A compound chaotic sequence generation module is used to generate a compound chaotic sequence using a Logistic chaotic map and a two-dimensional sine-cosine chaotic map; The image encryption module is used to encrypt the original multispectral image based on the composite chaotic sequence to obtain the encrypted image corresponding to the original multispectral image.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the multispectral image encryption method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the multispectral image encryption method described in any one of claims 1 to 6 is implemented.

Images