WO2019024160A1

WO2019024160A1 - Image tampering detection method and system, electronic device, and readable storage medium

Info

Publication number: WO2019024160A1
Application number: PCT/CN2017/100041
Authority: WO
Inventors: 王健宗; 王晨羽; 黄章成; 肖京
Original assignee: 平安科技（深圳）有限公司
Priority date: 2017-08-04
Filing date: 2017-08-31
Publication date: 2019-02-07
Also published as: CN107464237A

Abstract

Provided are an image tampering detection method and system, an electronic device, and a readable storage medium. The method comprises: performing preset compression and decompression processing on an image to be detected to obtain multiple image blocks corresponding to the image (S10); performing, according to a predetermined analysis algorithm, analysis of a pixel compression count of each image block to determine whether tampering has occurred on any of the image blocks (S20); and if any image block has been tampered with, determining the image to be a tampered image (S30). The method increases accuracy of detecting image tampering.

Description

Image tamper detecting method, system, electronic device and readable storage medium

The present application claims priority to Chinese Patent Application No. 201710659580.9, entitled "Image tampering detection method, electronic device and readable storage medium", which is filed on August 4, 2017, the entire contents of which are incorporated by reference. The way is combined in this application.

Technical field

The present invention relates to the field of computer technologies, and in particular, to an image tamper detecting method, system, electronic device, and readable storage medium.

Background technique

At present, in the claims business scenario, the claim information provided by the user, such as the damage photograph of the vehicle, needs to be determined. The damage degree will affect the final claim amount, so it is necessary to perform PS identification, that is, image tampering detection on the vehicle damage photo. Although there are image tamper detection algorithms in the industry to achieve automatic PS detection of images, the existing image tamper detection algorithm relies on complex feature extraction, and the extracted features are not robust to tamper type changes, image tamper detection The accuracy is not guaranteed and the detection error rate is high.

Summary of the invention

An object of the present invention is to provide an image tamper detecting method, an electronic device, a system, and a readable storage medium, aiming at improving the accuracy of image tampering detection.

To achieve the above object, the present invention provides an electronic device including: a memory, a processor, and an image tamper detecting system stored on the memory and operable on the processor, the image tamper detecting The system implements the following steps when executed by the processor:

A. performing preset compression and decompression processing on the detected image to obtain a plurality of image blocks corresponding to the image to be detected;

B. Perform pixel analysis times on each image block according to a predetermined analysis algorithm to analyze whether there is tampering in each image block;

C. If there is a tampering condition of the image block, determine that the image to be detected is a tamper image.

In addition, in order to achieve the above object, the present invention further provides an image tampering detecting method, where the image tampering detecting method includes:

Further, in order to achieve the above object, the present invention also provides a computer readable storage medium storing an image tampering detection system, the image tamper detecting system being executable by at least one processor to implement As steps:

Further, in order to achieve the above object, the present invention further provides an image tamper detecting system, which is stored in a memory and can be executed by at least one processor to implement steps as follows:

The image tamper detecting method, the electronic device, the system and the readable storage medium provided by the invention obtain a corresponding plurality of image blocks by compressing and decompressing the image to be detected; and performing pixel compression times analysis on each image block according to a predetermined analysis algorithm To analyze whether each image block and the image to be detected have tampering conditions. Since it is only necessary to analyze whether each image block has tampering according to the number of pixel compressions of each image block of the image to be detected, thereby determining whether the image to be detected is falsified, no complicated feature extraction is required, and various tamper types can be detected. Improve the accuracy of image tamper detection.

DRAWINGS

FIG. 1 is a schematic diagram of an optional application environment according to various embodiments of the present invention; FIG.

2 is a schematic diagram of a hardware architecture of an embodiment of the electronic device of FIG. 1;

FIG. 3 is a schematic flow chart of an embodiment of an image tampering detecting method according to the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be noted that the descriptions of "first", "second" and the like in the present invention are for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the indicated technical features. quantity. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly. In addition, the technical solutions between the various embodiments may be combined with each other, but must be based on the realization of those skilled in the art, and when the combination of the technical solutions is contradictory or impossible to implement, it should be considered that the combination of the technical solutions does not exist. It is also within the scope of protection required by the present invention.

FIG. 1 is a schematic diagram of an optional application environment according to various embodiments of the present invention.

In the present embodiment, the present invention is applicable to an application environment including, but not limited to, an electronic device 1, a terminal device 2, and a network 3. The electronic device 1 is an apparatus capable of automatically performing numerical calculation and/or information processing in accordance with an instruction set or stored in advance. The electronic device 1 may be a computer, a single network server, a server group composed of a plurality of network servers, or a cloud-based cloud composed of a large number of hosts or network servers, wherein the cloud computing is a type of distributed computing, A super virtual computer consisting of a loosely coupled set of computers.

The terminal device 2 includes, but is not limited to, any electronic product that can interact with a user through a keyboard, a mouse, a remote controller, a touch pad, or a voice control device, for example, a personal computer, a tablet computer, a smart phone, or an individual. Digital Assistant (PDA), game console, Internet Protocol Television (IPTV), smart wearable device, etc.

The network 3 may be an intranet, an Internet, a global mobile communication system (Global S image tampering detection, GSM), and a Wideband Code Division Multiple Access (WCDMA). Wireless or wired networks such as 4G networks, 5G networks, Bluetooth, Wi-Fi, etc. The electronic device 1 is communicatively connected to one or more of the terminal devices 2 via the network 3 respectively.

FIG. 2 is a schematic diagram of an optional hardware architecture of the electronic device 1 of FIG. 1. In this embodiment, the electronic device 1 may include, but is not limited to, a memory 11 and a processor 12 that are communicably connected to each other through a system bus. Network interface 13. It is to be noted that FIG. 2 only shows the electronic device 1 having the components 11-13, but it should be understood that not all illustrated components may be implemented, and more or fewer components may be implemented instead.

The memory 11 includes at least one type of readable storage medium including a flash memory, a hard disk, a multimedia card, a card type memory (eg, SD or DX memory, etc.), and a random access memory (RAM). , static random access memory (SRAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), programmable read only memory (PROM), magnetic memory, magnetic disk, optical disk, and the like. In some embodiments, the memory 11 may be an internal storage unit of the electronic device 1, such as a hard disk or a memory of the electronic device 1. In other embodiments, the memory 11 may also be an external storage device of the electronic device 1, such as a plug-in hard disk equipped on the electronic device 1, a smart memory card (SMC), and a secure digital device. (Secure Digital, SD) card, flash card, etc. Of course, the memory 11 can also include both the internal storage unit of the electronic device 1 and its external storage device. In this embodiment, the memory 11 is generally used to store an operating system installed in the electronic device 1 and various types of application software, such as program codes of the image tamper detecting system 10 and the like. Further, the memory 11 can also be used to temporarily store various types of data that have been output or are to be output.

The processor 12 may be a Central Processing Unit (CPU), controller, microcontroller, microprocessor, or other data processing chip in some embodiments. The processor 12 is typically used to control the overall operation of the electronic device 1, such as performing control and processing related to data interaction or communication with the terminal device 2. In this embodiment, the processor 12 is configured to run program code or process data stored in the memory 11, such as running the image tamper detecting system 10 and the like.

The network interface 13 may comprise a wireless network interface or a wired network interface, which is typically used to establish a communication connection between the electronic device 1 and other electronic devices. In this embodiment, the network interface 13 is mainly used to connect the electronic device 1 to one or more of the terminal devices 2 through the network 3, in the electronic device 1 and one or more of the terminals. A data transmission channel and a communication connection are established between the devices 2.

Image tampering detection system 10 includes at least one computer readable instruction stored in said memory 11 that is executable by said processor 12 to implement various embodiments of the present application.

Wherein, when the image tampering detection system 10 is executed by the processor 12, the following steps are implemented:

Step S1, performing preset compression and decompression processing on the image to be detected, to obtain a plurality of image blocks corresponding to the image to be detected;

In this embodiment, the image tampering detection system receives an image tampering detection request sent by the user including the image to be detected, for example, receiving an image tampering detection request sent by the user through a mobile phone, a tablet computer, a self-service terminal device, or the like, such as receiving the user in the mobile phone. Image tampering detection request sent by a pre-installed client in a terminal such as a tablet computer or a self-service terminal device, or receiving image tampering detection sent by a user on a browser system in a terminal such as a mobile phone, a tablet computer, or a self-service terminal device request.

After receiving the image to be detected that needs to be image tampering detection, the image to be detected is subjected to preset compression and decompression processing, for example, the image to be detected is mesh-divided to form a small image mesh, and the image small mesh is compressed. And decompressing the processing to obtain a plurality of image blocks corresponding to the image to be detected.

Step S2, performing pixel compression times analysis on each image block according to a predetermined analysis algorithm, to analyze whether each image block has a tampering condition;

In this embodiment, after the image to be detected is compressed and decompressed to obtain a corresponding plurality of image blocks, the number of times of pixel compression is analyzed for each image block by using a predetermined analysis algorithm, for example, a condition that each image block undergoes one compression can be calculated. Probability and/or conditional probability of secondary compression, and analyze whether each image block is compressed once or twice, that is, the number of pixel compressions corresponding to each image block is analyzed. In the process of image tampering, the tampering party generally divides, compresses and decompresses the image, and then replaces the falsified image block with the original image block according to the position of the falsified image block in the image, and each other original The image block and the falsified image block are combined and reconstructed to obtain a reconstructed image, that is, a falsified image. It can be seen that the image has been subjected to a compression process when it is tampered with, and is used to add tampering information, so that the analysis is to be detected. After the number of pixel compressions corresponding to each image block corresponding to the image, it is possible to analyze whether there is tampering in each image block. For example, in this embodiment, after performing a predetermined compression and decompression process on the image to be detected to obtain a corresponding plurality of image blocks, if it is analyzed that the number of pixel compressions corresponding to the image block is 2, it is explained that before the image block is detected. The image block has undergone one compression process. Therefore, the image block is a tampered image block, that is, the image block has a tampering condition; on the contrary, if the pixel compression number corresponding to the image block is 2, the description is An image block is an image block that has not been tampered with, that is, there is no tampering in the image block.

In step S3, if there is a tampering condition of the image block, it is determined that the image to be detected is a tamper image.

In this embodiment, after analyzing whether there is a tampering condition in each image block, it may be further determined whether the image to be detected is a tamper image. For example, if the number of pixel compressions of all the image blocks corresponding to the image to be detected is 1, that is, it is determined that there is no tampering condition in all the image blocks, it is determined that the image to be detected does not have a tampering condition, that is, the image to be detected Not tampering with the image. If the number of pixel compressions of the image block in the image block corresponding to the image to be detected is 2, that is, it is determined that there is a tampering condition of the image block, determining that the image to be detected has a tampering condition, that is, the image to be detected is tampering image.

In this embodiment, a plurality of image blocks are obtained by compressing and decompressing the image to be detected; and performing pixel compression times on each image block according to a predetermined analysis algorithm to analyze whether each image block and the image to be detected are falsified. Happening. Since it is only necessary to analyze whether each image block has tampering according to the number of pixel compressions of each image block of the image to be detected, thereby determining whether the image to be detected is falsified, no complicated feature extraction is required, and various tamper types can be detected. Improve the accuracy of image tamper detection.

In an optional embodiment, on the basis of the foregoing embodiment of FIG. 2, when the image tampering detection system 10 is executed by the processor 12 to implement the step S1, the method specifically includes:

Dividing the detected image into a mesh, dividing the image to be detected into a plurality of N*M (for example, 8*8) image small meshes, where N and M are positive integers;

Each image grid is transformed by a preset type transform function (for example, a DCT (Discrete Cosine Transform) transform function) to obtain corresponding transform grid data. For example, using a DCT transform function to perform a transform according to a predetermined one-time compressed quantization step to obtain corresponding transform grid data;

Performing compression on the transformed mesh data corresponding to each image grid according to a predetermined compression format (for example, JPEG) to obtain corresponding mesh compressed data;

Decompressing the grid compressed data corresponding to each image grid to obtain corresponding grid decompressed data, and adopting a preset type inverse transform function for the grid decompressed data corresponding to each image grid (for example, DCT (Discrete Cosine) Transform, discrete cosine transform) inverse transform function) performs inverse transform to obtain the corresponding image block.

In this embodiment, the image to be detected is mesh-divided into a plurality of image small grids, and DCT is utilized. The transformation function transforms the image small grid to obtain the grid data, and then performs compression and decompression processing, and then inversely transforms the DCT inverse transform function to obtain a plurality of image blocks corresponding to the image to be detected, so as to facilitate more accurate subsequent image blocks. The pixel compression number analysis is performed, and by dividing the image to be detected into a plurality of image blocks, determining the tampering condition of the image to be detected according to whether there is a tampering condition in each image block, the accuracy of the image tampering detection can be further improved.

In an optional embodiment, when the image tampering detection system 10 is executed by the processor 12 to implement the step S2, the predetermined analysis algorithm includes:

The conditional probability that each pixel x of the image block is compressed once is denoted as p(x|H ₀ ), and the conditional probability of secondary compression is denoted as p(x|H ₁ ), where p(x|H ₁ ) =p _DQ (x; Q ₁ , Q ₂ ), p(x|H ₀ )=p _NDQ (x; Q ₂ ), Q ₁ is the preset quantization step size of the first compression, and Q ₂ is the preset two Secondary compression quantization step size;

Calculate two conditional probabilities p(x|H ₁ ) and p(x|H ₀ ) corresponding to each pixel x, and according to the calculated two conditional probabilities p(x|H ₁ ) and p(x|H ₀ ) Value, the number of compressions corresponding to each pixel x is analyzed; for example, the likelihood ratio of pixel x can be calculated

If L(x)>1, it is determined that the number of compressions corresponding to the pixel x is two; if L(x)≤1, it is determined that the number of compressions corresponding to the pixel x is one.

If the number of compressions corresponding to all the pixels in the image block is one, it is determined that the image block does not have a tampering condition, or if the number of compressions corresponding to the pixel in the image block is two, it is determined that the image block has a tampering condition.

In an optional implementation manner, the preset type transform function in the preset compression and decompression process of the image to be detected may be a discrete cosine transform DCT transform function, and the preset type inverse transform function may be a DCT inverse transform function. . Conditional probability that each pixel x of the image block undergoes secondary compression

Where x ≠ 0, n _DQ (x) is a periodic function of the DCT coefficients,

Conditional probability of one compression per pixel x of an image block

Where p _Q(v) = n _Q (x) * p _NQ (x), x ≠ 0, n _Q (x) = n _{Q, 0} (x) * g _Q (x),

Q is the preset quantization step size, and μ _e is the mean value of the estimation error of the DCT coefficient distribution.

The variance of the estimated error for the DCT coefficient distribution. Estimation of the variance of the error

The smaller the detection speed is, the slower the accuracy is. The average value of the estimated error μ _e is an empirical value, which requires multiple attempts to determine. If a range of mean value can be specified in advance, then try to make an error estimate within the range. The smallest one.

In this embodiment, a conditional probability of one compression of each pixel of the image block and a conditional probability of being subjected to secondary compression are calculated, and a likelihood ratio of the pixel is calculated according to two conditional probabilities of each pixel. According to the likelihood ratio, the number of compressions corresponding to the pixel can be accurately and accurately analyzed according to the likelihood ratio, so as to analyze whether the image block has a tampering condition, and then accurately analyze whether the image to be detected is a tamper image.

As shown in FIG. 3, FIG. 3 is a schematic flowchart of an image tampering detection method according to an embodiment of the present invention. The image tampering detection method includes the following steps:

Step S10, performing preset compression and decompression processing on the image to be detected, to obtain a plurality of image blocks corresponding to the image to be detected;

Step S20, performing pixel compression times analysis on each image block according to a predetermined analysis algorithm, to analyze whether each image block has a tampering condition;

In this embodiment, after the image to be detected is compressed and decompressed to obtain a corresponding plurality of image blocks, the number of times of pixel compression is analyzed for each image block by using a predetermined analysis algorithm, for example, a condition that each image block undergoes one compression can be calculated. Probability and/or conditional probability of secondary compression, and analyze whether each image block is compressed once or twice, that is, the number of pixel compressions corresponding to each image block is analyzed. In the process of image tampering, the tampering party generally divides, compresses and decompresses the image, and then replaces the falsified image block with the original image block according to the position of the falsified image block in the image, and each other original The image block and the falsified image block are combined and reconstructed to obtain a reconstructed image, that is, a falsified image. It can be seen that the image has been subjected to a compression process for tampering when it is falsified, and is used to add tampering information. Therefore, after analyzing the number of pixel compressions corresponding to each image block corresponding to the image to be detected, it is possible to analyze whether each image block is There is a tampering situation. For example, in this embodiment, after performing a predetermined compression and decompression process on the image to be detected to obtain a corresponding plurality of image blocks, if it is analyzed that the number of pixel compressions corresponding to the image block is 2, it is explained that before the image block is detected. The image block has undergone one compression process. Therefore, the image block is a tampered image block, that is, the image block has a tampering condition; on the contrary, if the pixel compression number corresponding to the image block is 2, the description is An image block is an image block that has not been tampered with, that is, there is no tampering in the image block.

In step S30, if there is a tampering condition of the image block, it is determined that the image to be detected is a tamper image.

In this embodiment, after analyzing whether there is a tampering condition in each image block, it may be further determined whether the image to be detected is a tamper image. For example, if all the maps corresponding to the image to be detected are If the pixel compression number of the image block is 1, that is, it is determined that there is no tampering condition in all the image blocks, it is determined that the image to be detected does not have a tampering condition, that is, the image to be detected is not a tamper image. If the number of pixel compressions of the image block in the image block corresponding to the image to be detected is 2, that is, it is determined that there is a tampering condition of the image block, determining that the image to be detected has a tampering condition, that is, the image to be detected is tampering image.

In an optional embodiment, based on the foregoing embodiment of FIG. 3, the step S10 specifically includes:

In this embodiment, the image to be detected is meshed into a plurality of image small meshes, and the image small mesh is transformed by the DCT transform function to obtain the mesh data, and then subjected to compression and decompression processing, and then inversed by the DCT inverse transform function. Transforming a plurality of image blocks corresponding to the image to be detected, so as to facilitate more accurate analysis of the number of times of pixel compression for each image block, and by dividing the image to be detected into several image blocks, determining whether there is tampering according to each image block. The tampering of the image to be detected can further improve the accuracy of image tampering detection.

In an optional embodiment, the predetermined analysis algorithm in the step S20 includes:

Where x ≠ 0, n _DQ (x) is a periodic function of the DCT coefficients,

Conditional probability of one compression per pixel x of an image block

Where p ₀ (v)=n _Q (x)*p _DQ (x), x≠0, n _Q (x)=n _Q,0 (x)*g _Q (x),

In this embodiment, a condition probability of one compression of each pixel of the image block and a conditional probability of secondary compression are calculated, and a likelihood ratio of the pixel is calculated according to two conditional probabilities of each pixel, according to the likelihood ratio. The number of compressions corresponding to the pixel can be accurately and accurately analyzed to analyze whether the image block has tampering condition, and then whether the image to be detected is a tamper image is accurately analyzed.

Moreover, the present invention also provides a computer readable storage medium storing an image tamper detecting system, the image tamper detecting system being executable by at least one processor to cause the at least one processor The specific implementation process of the image tampering detection method, such as the steps S10, S20, and S30, is as described above, and is not described here.

It is to be understood that the term "comprises", "comprising", or any other variants thereof is intended to encompass a non-exclusive inclusion, such that a process, method, article, or The device includes not only those elements, but also other elements not explicitly listed, or elements that are inherent to such a process, method, article, or device. An element that is defined by the phrase "comprising a ..." does not exclude the presence of additional equivalent elements in the process, method, item, or device that comprises the element.

Through the description of the above embodiments, those skilled in the art can clearly understand that the foregoing embodiment method can be implemented by means of software plus a necessary general hardware platform, and can also be implemented by hardware, but in many cases, the former is A better implementation. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a storage medium (such as ROM/RAM, disk, The optical disc includes a number of instructions for causing a terminal device (which may be a cell phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

The preferred embodiments of the present invention have been described above with reference to the drawings, and are not intended to limit the scope of the invention. The serial numbers of the embodiments of the present invention are merely for the description, and do not represent the advantages and disadvantages of the embodiments. Additionally, although logical sequences are shown in the flowcharts, in some cases the steps shown or described may be performed in a different order than the ones described herein.

A person skilled in the art can implement the invention in various variants without departing from the scope and spirit of the invention. For example, the features of one embodiment can be used in another embodiment to obtain a further embodiment. Any modifications, equivalent substitutions and improvements made within the technical concept of the invention are intended to be included within the scope of the invention.

Claims

An electronic device, comprising: a memory, a processor, and an image tamper detecting system stored on the memory and operable on the processor, the image tamper detecting system being The processor implements the following steps when it executes:

A. performing preset compression and decompression processing on the detected image to obtain a plurality of image blocks corresponding to the image to be detected;

B. Perform pixel analysis times on each image block according to a predetermined analysis algorithm to analyze whether there is tampering in each image block;

C. If there is a tampering condition of the image block, determine that the image to be detected is a tamper image.
The electronic device according to claim 1, wherein when the image tampering detection system is executed by the processor to implement the step A, the method comprises:

A1, performing mesh segmentation on the image to be detected, dividing the image to be detected into a plurality of image meshes of N*M, and N and M are positive integers;

A2: Performing transformation on each image grid by using a preset type transformation function to obtain corresponding transformation grid data;

A3. Performing compression on the transformed mesh data corresponding to each image grid according to a predetermined compression format to obtain corresponding mesh compressed data;

A4, decompressing the grid compressed data corresponding to each image grid, obtaining the corresponding grid decompressed data, and inversely transforming the grid decompressed data corresponding to each image grid by using a preset type inverse transform function to obtain a corresponding Image block.
The electronic device according to claim 2, wherein the preset type transform function is a discrete cosine transform DCT transform function, and the preset type inverse transform function is a DCT inverse transform function.
The electronic device according to claim 1 or 2 or 3, wherein the predetermined analysis algorithm comprises:

The conditional probability that each pixel x of the image block is compressed once is denoted as p(x|H 0 ), and the conditional probability of secondary compression is denoted as p(x|H 1 ), where p(x|H 1 ) =p DQ (x; Q 1 , Q 2 ), p(x|H 0 )=p NDQ (x; Q 2 ), Q 1 is the preset quantization step size of the first compression, and Q 2 is the preset two Secondary compression quantization step size;

Calculate two conditional probabilities p(x|H 1 ) and p(x|H 0 ) corresponding to each pixel x, and according to the calculated two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The value of each pixel x corresponding to the number of compressions;

If the number of compressions corresponding to all the pixels in the image block is one, it is determined that the image block does not have a tampering condition, or if the number of compressions corresponding to the pixel in the image block is two, it is determined that the image block has a tampering condition.
The electronic device according to claim 4, wherein said image tampering detection system is executed by said processor to implement said two conditional probabilities p(x|H 1 ) and p(x|H 0 according to the calculation The value of the step of analyzing the number of compressions per pixel x, including:

Calculate the likelihood ratio of pixel x

If L(x)>1, it is determined that the number of compressions corresponding to the pixel x is two;

If L(x)≤1, it is determined that the number of compressions corresponding to the pixel x is one.
An image tampering detecting method, wherein the image tampering detecting method comprises:

A. performing preset compression and decompression processing on the detected image to obtain a plurality of image blocks corresponding to the image to be detected;

B. Perform pixel analysis times on each image block according to a predetermined analysis algorithm to analyze whether there is tampering in each image block;

C. If there is a tampering condition of the image block, determine that the image to be detected is a tamper image.
The image tampering detecting method according to claim 6, wherein the step A comprises:

A1, performing mesh segmentation on the image to be detected, dividing the image to be detected into a plurality of image meshes of N*M, and N and M are positive integers;

A2: Performing transformation on each image grid by using a preset type transformation function to obtain corresponding transformation grid data;

A3. Performing compression on the transformed mesh data corresponding to each image grid according to a predetermined compression format to obtain corresponding mesh compressed data;

A4, decompressing the grid compressed data corresponding to each image grid, obtaining the corresponding grid decompressed data, and inversely transforming the grid decompressed data corresponding to each image grid by using a preset type inverse transform function to obtain a corresponding Image block.
The image tampering detecting method according to claim 7, wherein the preset type transform function is a discrete cosine transform DCT transform function, and the preset type inverse transform function is a DCT inverse transform function.
The image tampering detecting method according to any one of claims 6-8, wherein the predetermined analysis algorithm comprises:

The conditional probability that each pixel x of the image block is compressed once is denoted as p(x|H 0 ), and the conditional probability of secondary compression is denoted as p(x|H 1 ), where p(x|H 1 ) =p DQ (x; Q 1 , Q 2 ), p(x|H 0 )=p NDQ (x; Q 2 ), Q 1 is the preset quantization step size of the first compression, and Q 2 is the preset two Secondary compression quantization step size;

Calculate two conditional probabilities p(x|H 1 ) and p(x|H 0 ) corresponding to each pixel x, and according to the calculated two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The value of each pixel x corresponding to the number of compressions;

If the number of compressions corresponding to all the pixels in the image block is one, it is determined that the image block does not have a tampering condition, or if the number of compressions corresponding to the pixel in the image block is two, it is determined that the image block has a tampering condition.
The image tampering detecting method according to claim 9, wherein said analyzing each pixel x according to the calculated values of two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The steps of the number of compressions include:

Calculate the likelihood ratio of pixel x

If L(x)>1, it is determined that the number of compressions corresponding to the pixel x is two;

If L(x)≤1, it is determined that the number of compressions corresponding to the pixel x is one.
A computer readable storage medium, characterized in that the computer readable storage medium stores an image tampering detection system, and the image tampering detection system is executable by at least one processor to implement steps as follows:

A. performing preset compression and decompression processing on the detected image to obtain a plurality of image blocks corresponding to the image to be detected;

B. Perform pixel analysis times on each image block according to a predetermined analysis algorithm to analyze whether there is tampering in each image block;

C. If there is a tampering condition of the image block, determine that the image to be detected is a tamper image.
The computer readable storage medium of claim 11, wherein the step A comprises:

A1, performing mesh segmentation on the image to be detected, dividing the image to be detected into a plurality of image meshes of N*M, and N and M are positive integers;

A2: Performing transformation on each image grid by using a preset type transformation function to obtain corresponding transformation grid data;

A3. Performing compression on the transformed mesh data corresponding to each image grid according to a predetermined compression format to obtain corresponding mesh compressed data;

A4, decompressing the grid compressed data corresponding to each image grid, obtaining the corresponding grid decompressed data, and inversely transforming the grid decompressed data corresponding to each image grid by using a preset type inverse transform function to obtain a corresponding Image block.
The computer readable storage medium according to claim 12, wherein the preset type transform function is a discrete cosine transform DCT transform function, and the preset type inverse transform function is a DCT inverse transform function.
A computer readable storage medium according to any one of claims 11 to 13, The feature is that the predetermined analysis algorithm comprises:

The conditional probability that each pixel x of the image block is compressed once is denoted as p(x|H 0 ), and the conditional probability of secondary compression is denoted as p(x|H 1 ), where p(x|H 1 ) =p DQ (x; Q 1 , Q 2 ), p(x|H 0 )=p NDQ (x; Q 2 ), Q 1 is the preset quantization step size of the first compression, and Q 2 is the preset two Secondary compression quantization step size;

Calculate two conditional probabilities p(x|H 1 ) and p(x|H 0 ) corresponding to each pixel x, and according to the calculated two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The value of each pixel x corresponding to the number of compressions;

If the number of compressions corresponding to all the pixels in the image block is one, it is determined that the image block does not have a tampering condition, or if the number of compressions corresponding to the pixel in the image block is two, it is determined that the image block has a tampering condition.
The computer readable storage medium according to claim 14, wherein said analyzing each pixel x corresponds to the values of the calculated two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The steps of the number of compressions include:

Calculate the likelihood ratio of pixel x

If L(x)>1, it is determined that the number of compressions corresponding to the pixel x is two;

If L(x)≤1, it is determined that the number of compressions corresponding to the pixel x is one.
An image tampering detection system is characterized in that the image tampering detection system is stored in a memory and can be executed by at least one processor to implement steps as follows:

A. performing preset compression and decompression processing on the detected image to obtain a plurality of image blocks corresponding to the image to be detected;

B. Perform pixel analysis times on each image block according to a predetermined analysis algorithm to analyze whether there is tampering in each image block;

C. If there is a tampering condition of the image block, determine that the image to be detected is a tamper image.
The image tamper detecting system according to claim 16, wherein the step A comprises:

A1, performing mesh segmentation on the image to be detected, dividing the image to be detected into a plurality of image meshes of N*M, and N and M are positive integers;

A2: Performing transformation on each image grid by using a preset type transformation function to obtain corresponding transformation grid data;

A3. Performing compression on the transformed mesh data corresponding to each image grid according to a predetermined compression format to obtain corresponding mesh compressed data;

A4, decompressing the grid compressed data corresponding to each image grid, obtaining the corresponding grid decompressed data, and inversely transforming the grid decompressed data corresponding to each image grid by using a preset type inverse transform function to obtain a corresponding Image block.
The image tamper detecting system according to claim 17, wherein the preset type transform function is a discrete cosine transform DCT transform function, and the preset type inverse transform function is a DCT inverse transform function.
The image tamper detecting system according to any one of claims 16 to 18, wherein the predetermined analysis algorithm comprises:

The conditional probability that each pixel x of the image block undergoes one compression is denoted as p(xH 0 ), and the conditional probability of secondary compression is denoted as p(xH 1 ), where p(x|H 1 )=p DQ ( x; Q 1 , Q 2 ), p(x|H 0 )=p NDQ (x; Q 2 ), Q 1 is the quantization step size of the preset primary compression, and Q 2 is the quantization of the preset secondary compression Step size

Calculate two conditional probabilities p(x|H 1 ) and p(x|H 0 ) corresponding to each pixel x, and according to the calculated two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The value of each pixel x corresponding to the number of compressions;

If the number of compressions corresponding to all the pixels in the image block is one, it is determined that the image block does not have a tampering condition, or if the number of compressions corresponding to the pixel in the image block is two, it is determined that the image block has a tampering condition.
The image tamper detecting system according to claim 19, wherein said analyzing each pixel x according to the calculated values of two conditional probabilities p(x|H 1 ) and p(x|H 0 ) The steps of the number of compressions include:

Calculate the likelihood ratio of pixel x

If L(x)11, it is determined that the number of compressions corresponding to the pixel x is two;

If L(x)≤1, it is determined that the number of compressions corresponding to the pixel x is one.