A multispectral image encryption method, device, equipment and medium

Abstract

The application discloses a multispectral image encryption method and device, equipment and medium, and relates to the technical field of image encryption. The method comprises the following steps: generating a composite chaotic sequence by using a Logistic chaotic mapping and a two-dimensional sine-cosine chaotic mapping; and encrypting an original multispectral image based on the composite chaotic sequence to obtain an encrypted image corresponding to the original multispectral image. The method solves the problems of low security and poor attack resistance of the existing image encryption algorithm using a single chaotic system, and improves the security and attack resistance.

Description

Technical Field

[0001] This application relates to the field of image encryption technology, and in particular to a multispectral image encryption method, apparatus, device and medium. Background Technology

[0002] Remote sensing technology, originating in the 1960s, is a comprehensive technology that uses various sensors to identify and detect various objects on the ground. It developed from aerial photography, along with advancements in aerospace and electronics technologies. Remote sensing utilizes sensors mounted on satellites or other aircraft to analyze the electromagnetic radiation characteristics of targets of interest on land and in the ocean. A remote sensing system consists of several components: an information source, remote sensors (space cameras, multispectral scanners, synthetic aperture radar, etc.), a remote sensing platform (aircraft, satellites, etc.), information transmission and reception equipment, and information processing equipment. Information transmission equipment serves as the carrier for transmission between remote sensing platforms such as satellites and aircraft and the ground. Information processing equipment performs filtering, geometric correction, and other effective processing on the remote sensing information received from the ground to obtain clear and useful information on properties and states. While space multispectral images provide more detailed spectral information about ground features, their data volume increases dramatically, posing challenges to airborne and spaceborne data transmission and storage. Furthermore, because certain reconnaissance and surveillance operations aim to prevent other countries or organizations from cracking the data, it is essential to encrypt multispectral images in addition to encrypting communication links to ensure data security.

[0003] Existing encryption algorithms have shortcomings in key space and key sensitivity, resulting in low security and poor resistance to attacks. Therefore, there is an urgent need for a multispectral image encryption method with high security and strong resistance to attacks. Summary of the Invention

[0004] The purpose of this application is to provide a multispectral image encryption method, apparatus, device, and medium that can improve security and resistance to attacks.

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

[0006] Firstly, this application provides a multispectral image encryption method, including:

[0007] A composite chaotic sequence is generated using the Logistic chaotic mapping and the two-dimensional sine-cosine chaotic mapping.

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

[0009] Secondly, this application provides a multispectral image encryption device, comprising:

[0010] A composite chaotic sequence generation module is used to generate composite chaotic sequences using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping.

[0011] The image encryption module is used to encrypt the original multispectral image based on a complex chaotic sequence, so as to obtain an encrypted image corresponding to the original multispectral image.

[0012] Thirdly, this application provides a computer device, including: 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-described multispectral image encryption method.

[0013] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described multispectral image encryption method.

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

[0015] This application provides a multispectral image encryption method, apparatus, device, and medium. It utilizes Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping to generate a composite chaotic sequence. Based on the composite chaotic sequence, the original multispectral image is encrypted to obtain an encrypted image corresponding to the original multispectral image. This solves the problems of low security and poor resistance to attacks in existing image encryption algorithms that use a single chaotic system, and improves security and resistance to attacks. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an application environment diagram of a multispectral image encryption method according to an embodiment of this application;

[0018] Figure 2 This is a schematic flowchart of a multispectral image encryption method provided in an embodiment of this application;

[0019] Figure 3 A detailed flowchart illustrating the multispectral image encryption method provided in an embodiment of this application;

[0020] Figure 4 This is a schematic diagram of the functional modules of a multispectral image encryption device provided in an embodiment of this application;

[0021] Figure 5 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The multispectral image encryption method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be set up independently, integrated into server 104, or placed in the cloud or on another server. Terminal 102 can send the raw multispectral image to server 104. After receiving the raw multispectral image, server 104 uses Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping to generate a composite chaotic sequence based on set initial values. Based on the composite chaotic sequence, the raw multispectral image is encrypted to obtain an encrypted image corresponding to the raw multispectral image. Server 104 can then send the encrypted image corresponding to the raw multispectral image back to terminal 102. Furthermore, in some embodiments, the multispectral image encryption method can also be implemented independently by server 104 or terminal 102. For example, terminal 102 can directly encrypt the raw multispectral image, or server 104 can obtain the raw multispectral image from the data storage system and encrypt it.

[0025] The terminal 102 can be, but is not limited to, various desktop computers, laptops, smartphones, and tablets. The server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers, or it can be a cloud server.

[0026] In one exemplary embodiment, such as Figure 2 As shown, a multispectral image encryption method is provided. This method is executed by a computer device, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, the method is applied to... Figure 1Taking server 104 as an example, the explanation includes the following steps 201 to 202. Wherein:

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

[0028] Step 202: Based on the composite chaotic sequence, encrypt the original multispectral image to obtain the encrypted image corresponding to the original multispectral image.

[0029] Implementing steps 201 to 202 above solves the problems of low security and poor resistance to attacks in existing image encryption algorithms that use a single chaotic system, thereby improving security and resistance to attacks.

[0030] The generation process of a complex chaotic sequence includes the following steps:

[0031] 1) Using the Logistic chaotic mapping, a Logistic chaotic sequence is iteratively generated based on the first set initial value;

[0032] 2) Take the iteration values ​​corresponding to the first and second set iteration numbers from the Logistic chaotic sequence as the second set initial values ​​for the two-dimensional sine-cosine chaotic mapping, and iteratively generate a two-dimensional sine-cosine chaotic sequence;

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

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

[0035] This application proposes a chaotic system that combines Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping. The two chaotic systems are used together to perform two rounds of diffusion and scrambling processing on the image.

[0036] The Logistic chaotic mapping is shown in the following equation:

[0037] x i+1 =4μx i (1-x i (1);

[0038] Where, x i+1 Let x be the (i+1)th iteration value in the Logistic chaotic mapping. iLet μ be the value of the i-th iteration in the Logistic chaotic mapping, and let μ be the control parameter of the Logistic chaotic mapping, μ∈(0,1). The system is in a chaotic state when the parameter μ∈[0.89,1].

[0039] The two-dimensional sine-cosine chaotic mapping overcomes the shortcomings of one-dimensional chaotic systems, such as narrow chaotic intervals and simple structures. This chaotic system has better randomness and ergodicity, and also has a wider hyperchaotic range, making it suitable for image encryption. Its expression is shown in the following equation:

[0040]

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

[0042] The Logistic chaotic mapping and the two-dimensional sine-cosine chaotic mapping have overlapping value ranges. To increase the randomness of the chaotic system, this application introduces the Logistic chaotic mapping to generate the initial values ​​for the two-dimensional sine-cosine chaotic mapping. Specifically, the values ​​of the Kth iteration (K being the first set iteration number) and the K+M×N iteration (K+M×N being the second set iteration number) 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 generated iteratively by providing the values ​​of control coefficients α and β. To avoid the single-valuedness and periodicity of the chaotic system, the first 10,000 points of the two-dimensional sine-cosine chaotic sequence are discarded, resulting in an intermediate chaotic sequence. The intermediate chaotic sequence of length M×N is then truncated using 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 image size, thus improving 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, meaning each high-frequency image or each low-frequency image corresponds to one key. The keys can be generated using the following formula:

[0044]

[0045] In the formula, Kn is the key corresponding to the nth spectral segment, abs() represents taking the absolute value, ceil() represents rounding up, M×N is the length of the chaotic sequence, and δ is the computational precision. 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 this application, such as Figure 3 As shown, step 202 above is replaced by steps 301 to 303:

[0047] Step 301: Divide the original multispectral image into spectral bands to obtain several high-frequency images and several low-frequency images.

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

[0049] Step 303: 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.

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

[0051] 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, specifically including steps 401 to 404:

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

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

[0054] Step 403: Use the third composite chaotic sequence to encrypt the first intermediate encrypted image to obtain the second intermediate encrypted image corresponding to the high-frequency image; the third composite chaotic sequence is generated by Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping based on a third initial value; the third initial value is the normalized pixel mean; the normalized pixel mean is calculated by averaging the gray values ​​of all pixels in 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 401-403 to obtain the encrypted sub-image corresponding to the high-frequency image.

[0056] Step 403 specifically includes:

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

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

[0059] The preceding spectral bands with relatively concentrated energy are the high-frequency images. For each high-frequency image, a two-round encryption-diffusion strategy is employed. Each round of encryption-diffusion includes steps 401-406, namely, spatial scrambling, initial encryption, and diffusion encryption. Specifically: given the initial values ​​of the composite chaotic sequence and the initial values ​​of the control parameters, after a certain number of iterations, the generated discrete sequence (the first composite chaotic sequence) is used as the row and column coordinates of the high-frequency image to achieve spatial scrambling of the high-frequency image. Then, the scrambled image is encrypted using the second composite chaotic sequence. The initial encryption steps are 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 This constitutes the second complex chaotic sequence, X i1 Y represents the pixel x-coordinate matrix in the second composite chaotic sequence. i1 This represents the pixel ordinate matrix in the second composite chaotic sequence. and X i1 and Y i1 The corresponding inverse sequence matrix, This represents the XOR operation.

[0062] To enhance the anti-attack capability of image data, further diffusion encryption processing is required on the encrypted data. The normalized pixel mean is used as the initial value x0 of the composite chaotic sequence, and the initial value y0 and other control parameters (μ, α, and β) are given. After a certain number of iterations, a third composite chaotic sequence (diffusion sequence) is generated. Q' is expanded into 1-dimensional 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 Equation (5) below.

[0063]

[0064] Where G represents the second intermediate encrypted image corresponding to the high-frequency image, X i2 and Y i2 This constitutes the second complex chaotic sequence, X i2 Y represents the pixel x-coordinate matrix in the second composite chaotic sequence. i2 This 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 high-frequency image data is completed. The second round of encryption can be carried out through similar operations, that is, the second intermediate encrypted image corresponding to the high-frequency image replaces the high-frequency image in step 402, the second intermediate encrypted image G corresponding to the high-frequency image is spatially scrambled, and then the scrambled second intermediate encrypted image is subjected to initial encryption and diffusion encryption processing in sequence through formulas (4) and (5). These will not be elaborated 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, specifically including the following steps 501 to 502:

[0067] Step 501: Spatial scrambling of the low-frequency image is performed using the fourth composite chaotic sequence to obtain the scrambled low-frequency image; the fourth composite chaotic sequence is generated based on the fourth initial value by the Logistic chaotic mapping and the two-dimensional sine-cosine chaotic mapping.

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

[0069] To improve algorithm efficiency, for other lower-energy spectral bands, i.e., low-frequency images, this application uses different strategies to encrypt each low-frequency image, and using different strategies also increases the difficulty of cracking. Image scrambling does not change the pixel values ​​of the image, so it cannot change the statistical properties of the original image, but it can significantly improve the visual effect of the encrypted image. To enhance the algorithm's resistance to attacks, this application uses a fourth composite chaotic sequence to spatially scramble the low-frequency images, and then applies an improved Arnold transform to the scrambled low-frequency images.

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

[0071]

[0072] Where 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 transformation, and (x', y') is the pixel value after transformation.

[0073] This application unfolds the low-frequency image into a one-dimensional vector and normalizes the gray values ​​of the pixels in the low-frequency image to the range of [0, 255]. In order to improve the key sensitivity and key space of the algorithm, this application introduces the key into the Arnold transform. The improved Arnold transform is shown in Equation (7).

[0074]

[0075] This application can also restore scrambled images by inverse transformation, the inverse transformation form of which is shown in equation (8).

[0076]

[0077] The information entropy of the multispectral image encryption method provided in this application is 11.8671, which is closer to the ideal value and exhibits better resistance to attacks. The ideal values ​​for number of pixel change rate (NPCR) and normalized average changing intensity (UACI) are 100% and 34.46%, respectively. The NPCR and UACI of the multispectral image encryption method provided in this application are closer to the ideal values, at 99.85% and 34.22%, respectively. Therefore, compared with existing encryption algorithms, the multispectral image encryption method provided in this application can better resist differential attacks.

[0078] By keeping the key unchanged and randomly changing the value of a pixel in a multispectral image, the sensitivity of the multispectral image encryption method provided in this application to plaintext is evaluated by the change in the encrypted bitstream. One hundred simulation experiments were conducted on QuickBird satellite impact data with different characteristics and specific compression ratios. The experiments show that the ciphertext bitstream change rate remains between 47.46% and 47.52%. Therefore, the multispectral image encryption method provided in this application is highly sensitive to plaintext images and can effectively resist differential attacks.

[0079] This application also provides an application scenario in which the above-described multispectral image encryption method is applied. Specifically, the multispectral image encryption method provided in this embodiment can be applied in an image encryption scenario. The image encryption scenario includes an image acquisition stage and an image encryption link; the original multispectral image enters the image encryption link from the image acquisition stage 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 based on a set initial value 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.

[0080] Based on the same inventive concept, this application also provides a multispectral image encryption device for implementing the multispectral image encryption method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more embodiments of the multispectral image encryption device provided below can be found in the limitations of the multispectral image encryption method described above, and will not be repeated here.

[0081] In one exemplary embodiment, such as Figure 4 As shown, a multispectral image encryption device is provided, comprising:

[0082] The composite chaotic sequence generation module T1 is used to generate composite chaotic sequences using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping.

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

[0084] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 5As shown, this computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores image encryption processing data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a multispectral image encryption method.

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

[0086] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0087] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[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, data stored, data displayed, 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 the relevant data must comply with relevant regulations.

[0089] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this 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 can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0090] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A multispectral image encryption method, characterized in that, The multispectral image encryption method includes: A composite chaotic sequence is generated using the Logistic chaotic mapping and the two-dimensional sine-cosine chaotic mapping. Based on a complex chaotic sequence, the original multispectral image is encrypted to obtain an encrypted image corresponding to the original multispectral image, specifically including: The original multispectral image is divided into spectral bands to obtain several high-frequency images and several low-frequency images; Step 401: Using the first composite chaotic sequence as the row and column coordinates of the high-frequency image, spatially scramble the high-frequency image to obtain the scrambled high-frequency image; the first composite chaotic sequence is generated by Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping based on the first initial value; Step 402: Use the second composite chaotic sequence to encrypt the scrambled high-frequency image to obtain the first intermediate encrypted image corresponding to the high-frequency image; the second composite chaotic sequence is generated by Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping based on the second initial value; Step 403: Use the third composite chaotic sequence to encrypt the first intermediate encrypted image to obtain the second intermediate encrypted image corresponding to the high-frequency image; the third composite chaotic sequence is generated by Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping based on a third initial value; the third initial value is the normalized pixel mean; the normalized pixel mean is calculated by averaging the gray values ​​of all pixels in 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 401-403 to obtain the encrypted sub-image corresponding to the high-frequency image; The low-frequency image is spatially scrambled using a fourth composite chaotic sequence to obtain a scrambled low-frequency image. The fourth composite chaotic sequence is generated based on a fourth initial value using a Logistic chaotic map and a two-dimensional sine-cosine chaotic map. An Arnold transform is performed on the scrambled low-frequency image 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.

2. The multispectral image encryption method according to claim 1, characterized in that, Based on a complex chaotic sequence, the original multispectral image is encrypted to obtain an encrypted image corresponding to the original multispectral image, specifically including: The original multispectral image is divided into spectral bands to obtain several high-frequency images and several low-frequency images; For each high-frequency image, the high-frequency image is encrypted using a composite chaotic sequence to obtain the 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, The generation process of a complex chaotic sequence specifically includes: Using the Logistic chaotic mapping, a Logistic chaotic sequence is iteratively generated based on a first set initial value; The iteration values ​​corresponding to the first and second set iteration numbers are taken from the Logistic chaotic sequence as the second set initial values ​​of the two-dimensional sine-cosine chaotic mapping, and the two-dimensional sine-cosine chaotic sequence is generated iteratively. Remove the first set number of iteration values ​​from the two-dimensional sine-cosine chaotic sequence to obtain the intermediate chaotic sequence; Extract a sequence of a set length from the intermediate chaotic sequence, and define the extracted sequence of the set length as a composite chaotic sequence; the set length is twice the number of pixels in the high-frequency image or the low-frequency image.

4. The multispectral image encryption method according to claim 1, characterized in that, The first intermediate encrypted image is encrypted using a third composite chaotic sequence to obtain the second intermediate encrypted image corresponding to the high-frequency image, specifically including: Expand the pixel matrix corresponding to the first intermediate encrypted image into a one-dimensional sequence data; The one-dimensional sequence data is encrypted using the third composite chaotic sequence to obtain the second intermediate encrypted image corresponding to the high-frequency image.

5. A multispectral image encryption device based on the multispectral image encryption method of claim 1, characterized in that, The multispectral image encryption device includes: A composite chaotic sequence generation module is used to generate composite chaotic sequences using Logistic chaotic mapping and two-dimensional sine-cosine chaotic mapping. The image encryption module is used to encrypt the original multispectral image based on a complex chaotic sequence, so as to obtain an encrypted image corresponding to the original multispectral image.

6. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the multispectral image encryption method according to any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the multispectral image encryption method according to any one of claims 1-4.

Images