CN107358568B

CN107358568B - Noise-disguised image information hiding transmission method

Info

Publication number: CN107358568B
Application number: CN201710464590.7A
Authority: CN
Inventors: 周诠; 回征; 李萱; 呼延烺; 刘娟妮; 魏佳圆; 李�荣
Original assignee: Xian Institute of Space Radio Technology
Current assignee: Xian Institute of Space Radio Technology
Priority date: 2017-06-19
Filing date: 2017-06-19
Publication date: 2020-11-20
Anticipated expiration: 2037-06-19
Also published as: CN107358568A

Abstract

The invention relates to a hidden transmission method of image information with noise camouflage, which is characterized in that secret information is disguised into noise and added into a carrier image to implement camouflage hiding, so that a legal receiver can correctly extract the secret information even if the secret information is compressed by 4 times of standard in transmission, and the carrier image is restored with high quality; after receiving the secret image, the illegal receiver cannot obtain a high-quality image, and even if knowing that the noise contains secret information, the illegal receiver cannot extract the secret image correctly. Compared with other similar methods, the method improves the safety and robustness of information hiding, and still has the capability of resisting high-power compression (4-8 times of JPEG2000 compression) and the high-quality carrier recovery capability under the condition of proper hiding capacity.

Description

Noise-disguised image information hiding transmission method

Technical Field

The invention relates to a data transmission method, in particular to a noise-disguised image information hiding transmission method, and belongs to the field of communication (such as data communication technology and the like).

Background

Data transmission and image processing are currently important research topics in the field of communications. With the development of science and technology, people have greater and greater requirements on high-resolution images, and data compression is imperative.

Information hiding, also called steganography, can be divided into airspace information hiding, transform domain information hiding and the like, as a new means of satellite covert communication, some important data (such as confidential ground object information obtained by a remote sensing satellite, data generated by the satellite, data uploaded on the ground and the like) can be hidden in satellite remote sensing data and transmitted through a public satellite channel, the aim of covert communication or expanding transmission capacity is fulfilled on the premise of not increasing transmission rate, and a safe information transmission way is provided for satellite communication.

After the information is hidden in the image, the image quality generally keeps the original state, and the enemy (illegal receiver) of the carrier image can obtain the secret information when the enemy (legal receiver) correctly receives the secret information. In some occasions, only one party (legal receiver) is expected to receive high-quality images, or only one party (adversary) is expected to receive poor-quality images or noise-polluted images, meanwhile, information of the encrypted images is not lost after data compression, the quality of carrier images is still high, and the conventional hiding method cannot meet the requirements.

Disclosure of Invention

The technical problem solved by the invention is as follows: the method overcomes the defects of the prior art, provides a noise disguised image information hiding and transmitting method, the transmitted image looks like an image polluted by noise, the confidential image can be compressed by a certain multiple of standard data, an illegal receiver can not obtain the secret information, a legal receiver can correctly obtain the secret information, a high-quality image can be recovered, and the method can be used for disguising the secret information and then hiding the secret information in the image for transmission.

The technical scheme of the invention is as follows: a method for hiding and transmitting noise-disguised image information comprises the following steps:

1) converting binary secret data S with the length of L into noise, wherein L is a positive integer;

2) carrying out position calibration on a carrier image A1 with the size of M x N, wherein M and N are positive integers;

3) forming a dense image;

4) performing standard data compression R times on the secret-containing image to obtain a compressed data stream;

5) the receiving end decompresses the compressed data stream to obtain a receiving image B;

6) extracting secret information;

7) the carrier image a1 is recovered.

The method for generating the binary secret data S in the step 1) comprises the following steps: the binary secret information S0 is added with an error correction code and becomes the binary secret data S.

And L is M, N and D is a number between 0 and 1.

The specific method for converting the binary secret data S with the length L into the noise in the step 1) is as follows: if Sj is 0, then Sj is converted into T1, if Sj is 1, then Sj is converted into T2, so that Q1 and Q2 … … QL are formed, wherein T1 is an integer from 0 to 127, and T2 is an integer from 128 to 255; where Sj is a bit in the binary secret data S, j is 1,2 … L.

The specific method for calibrating the position in the step 2) comprises the following steps: assuming that the carrier image a1 has a pixel value of 0 to 255 integers, L random integer pairs X1 and X2 are generated in accordance with the agreed pseudo random number generation method, X1 being an integer between 1 and M and X2 being an integer between 1 and N, each of X1 and X2 forming a coordinate P, P1, P2 … PL in total.

The specific method of the step 3) comprises the following steps: the pixel value at the Pj position is replaced by Qj, and j is 1,2 … L, thereby forming a dense image.

The specific process of extracting the secret information in the step 6) is as follows: generating L random integer pairs X1 and X2 according to an agreed pseudo-random number generation method, taking out a pixel value Qj corresponding to the position of a received image Pj, and if the Qj is more than or equal to 128, setting the information Sj to 1; if Qj <128, Sj is 0.

The specific method of the step 7) comprises the following steps: and replacing the pixel value of the Pj position of the received image B by the mean value of the surrounding pixel values without density, and keeping the rest pixel values unchanged to obtain a restored carrier image A1.

The number of the surrounding non-dense pixels is 2-4.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a high-efficiency information hiding method under the condition of not increasing actual pixels and not changing the data volume of a carrier, disguises secret information into an image similar to salt and pepper noise, increases the safety of hidden secret data and has compression resistance.

Compared with the prior art, the invention has the following substantive differences and progresses:

(1) the invention firstly generates L random number positions in the carrier image according to the length of the secret information, and the random number position transmitting and receiving ends agree without transmitting, thereby not introducing additional information and improving the hiding safety.

(2) The invention changes the secret information into two levels of noise T1 and T2, which is similar to salt and pepper noise, but not ordinary salt and pepper noise values 0 and 255, thus improving the adaptability of the hiding method to the carrier image.

(3) The T1 and T2 level values can be optimized, thereby being beneficial to the high-quality information extraction and carrier image recovery of a receiving end.

(4) After the confidential image is judged, the error rate of the confidential information can be reduced, no error code exists when the confidential image is compressed by 4 times, the error rate of the confidential information is still very low when the confidential image is compressed by high times, and the performance of the information hiding method in a severe environment is improved.

(5) The invention disguises the secret information into an image similar to salt and pepper noise, the image containing the secret information is seen to be polluted by noise or seriously polluted, the carrier image received by an illegal receiver is seriously distorted, even if high-efficiency filtering (such as a self-adaptive median filtering method) is adopted, the carrier can not be well recovered, and the secret information can not be correctly extracted, thereby achieving the purpose of puzzlement.

(6) The technical scheme of the invention is unique, breaks through the current situation that the dense carrier image generally keeps high quality in the traditional hiding method, intentionally deteriorates the quality of the carrier image, and a legal receiver can recover and process the carrier image to obtain the high-quality image due to the mastering of prior knowledge.

(7) According to the invention, the hiding and information extraction recovery processes are carried out in a space domain, complex transformation is not needed, and the method is very easy to realize.

(8) The information hiding capacity and the compression resistance of the invention can be designed in advance, when the hiding capacity is small, the compression resistance is extremely strong, the quality of the recovered carrier image is high, and the high-power compression resistance of most information hiding methods is not necessarily improved even if the hiding capacity is reduced. The invention can be used for information lossless hiding under the condition of high compression ratio, near lossless recovery of a carrier or lossless recovery in engineering.

Drawings

Fig. 1 shows the processing result (uncompressed) of the original image according to the present invention, where (a) is the original image, (b) is the dense image, PSNR is 23.0dB, (c) is the image after the optimal filtering of the illegal receiver, PSNR is 29.6dB d) is the recovered image of the legal receiver, PSNR is 41.8 dB;

fig. 2 shows the processing result (4-fold compression) of the original image, where (a) is the original image 4-fold compression recovery image PSNR 44.8dB, (b) is the dense image 4-fold compression recovery image, PSNR 22.8dB (c) is the image after the optimal filtering by the illegal receiver, PSNR 26.2dB d) is the recovery image of the legal receiver, and PSNR 35.5 dB.

Detailed Description

The performance of the invention is verified through simulation, and 1 8-bit international standard gray scale image (lena. bmp) with the size of 512 x 512 is adopted in the experiment for information hiding transmission.

1) The binary secret information S0 is converted into binary data S (length L) by adding an error correction code, and the conversion method is as follows:

the conversion from S-0 to T1, S-1 to T2, results in Q1, Q2 … … QL,

t1 is an integer between 0 and 127, T2 is an integer between 128 and 255;

L＝D*512*512，T1＝110，T2＝145

D＝1/8,C＝1/64

2) position-scaling a carrier image a1 of size M × N according to the secret information length L, assuming an image a1 pixel value of an integer between 0 and 255, by:

generating L integer pairs X1 and X2 by a conventional integer generation method, X1 being an integer between 1 and M, X2 being an integer between 1 and N, each of X1 and X2 forming a coordinate P, having a total of P1, P2 … PL;

3) forming a dense image:

replacing the pixel value at the position Pj with Qj, wherein j is 1,2 … L, and forming a dense image which is seemingly polluted by pepper-salt noise, and the hidden capacity C is L/(M N8) D/8;

4) carrying out standard data compression on the image containing the secret, wherein the compression R is 4 times to obtain a compressed data stream;

6) secret information extraction: generating L random number pairs X1 and X2 according to an agreed pseudo-random number generation method, wherein X1 is an integer from 1 to M, X2 is an integer from 1 to N, each X1 and X2 form a coordinate P with P1 and P2 … PL in total, extracting a pixel value Qj corresponding to the position of a received image Pj, and if Qj > is 128, information Sj is 1; if Qj <128, Sj ═ 0;

7) and (3) carrier image recovery: the pixel values at the Pj position of the received image B are replaced with the average of 2 to 4 surrounding pixel values without density, and the remaining pixel values are unchanged, resulting in a restored carrier image a1, where L is M × N × D, which is a number between 0 and 1, and the hidden capacity C is D/8.

The performance of the concealment algorithm is measured by using indexes such as PSNR (peak signal-to-noise ratio), concealment capacity C and the like. For an 8bit digital image of size H W, PSNR is used to reflect the degree of similarity between the original and recovered images, typically above 30 dB. PSNR is defined as follows:

in the formula, MSE is the mean square error between the original image and the dense image, and the calculation formula is

Where x is_ij,

Respectively, the pixel values of the original image and the dense image at (i, j).

The hidden capacity and performance simulation results of the invention are as follows:

information hiding capacity (relative value) C ═ L/(M · N · 8)

If L is D M N, C is D M N/(M N8) D/8

When D is 1/2, C is 1/16, which corresponds to hiding 1 bit per 2 pixels;

when D is 1/4, C is 1/32, which corresponds to hiding 1 bit per 4 pixels;

when D is 1/8, C is 1/64, which corresponds to hiding 1 bit per 8 or 2 × 4 pixels;

when D is 1/16, C is 1/128, which corresponds to hiding 1 bit per 16 or 4 × 4 pixels;

when D is 1/32, C is 1/256, which corresponds to hiding 1 bit per 32 or 4 × 8 pixels;

when D is 1/64, C is 1/512, which corresponds to hiding 1 bit per 64 or 8 × 8 pixels;

when D is 1/128, C is 1/1024, which corresponds to hiding 1 bit per 128 or 8 × 16 pixels;

when D is 1/256, C is 1/2048, which corresponds to hiding 1 bit per 256 or 16 by 16 pixels.

When the hidden capacity C is 1/64, the PSNR of the dense carrier image and the original image becomes 23dB for the lena. And the error rate of the recovered secret information is 0, and the PSNR of the recovered carrier image and the original image is 41 dB.

The JPEG2000 is used for compressing the image containing the secret carrier by 4 times, the error rate of the recovered secret information is 0.2 percent and is far less than 1 percent, and the PSNR is superior to 35dB (lena. bmp) in the error correction range of the error correction code.

The image containing the secret carrier is compressed by 8 times by JPEG2000, the secret information error rate is 0.068 to 6.8 percent and is less than 10 percent, and the error correction range of the error correction code is within the range of the error correction code. The PSNR of the restored carrier image is better than 31dB from the original image.

At the same time of high-speed data transmission, other low-speed data or part of high-speed data is often transmitted at the same time. The invention provides a method for hiding and transmitting secret information by using specially generated noise, the secret information is disguised as special noise, the special type noise can be filtered by adopting an optimized filtering method, so that the recovery quality of a carrier image is improved, the hidden quantity is always fixed, and the method has the characteristics of high performance, low complexity and easiness in realization of software and hardware, and has practical value in a plurality of occasions such as image carrying and transmission and the like.

In conclusion, the invention provides a simple and efficient compression-resistant hidden transmission method, secret information is disguised into noise and added into a carrier image to implement disguise and hiding, and the secret information is not lost even if 4 times of compression is carried out in transmission. After the enemy receives the confidential image, the information cannot be extracted due to the fact that the enemy is polluted, even if the enemy knows that the noise contains the confidential information, the information cannot be extracted correctly, and the information hiding safety is improved due to the fact that the sequence is random. Compared with other similar methods, the method has improved performance in both hidden capacity and PSNR.

The invention is not described in detail and is within the knowledge of a person skilled in the art.

Claims

1. A method for hiding and transmitting noise-disguised image information is characterized by comprising the following steps:

the method comprises the following steps: if Sj is 0, then Sj is converted into T1, if Sj is 1, then Sj is converted into T2, so that Q1 and Q2 … … QL are formed, wherein T1 is an integer from 0 to 127, and T2 is an integer from 128 to 255; where Sj is a certain bit in the binary secret data S, j is 1,2 … L;

3) forming a dense image;

6) extracting secret information;

7) recovering to obtain a carrier image A1;

the specific method for calibrating the position in the step 2) comprises the following steps: assuming that the pixel value of the carrier image A1 is an integer between 0 and 255, L random integer pairs X1 and X2 are generated according to an agreed pseudo-random number generation method, wherein X1 is an integer between 1 and M, X2 is an integer between 1 and N, and each integer pair X1 and X2 forms a coordinate Pj, j is 1 and 2 … L;

the specific method of the step 3) comprises the following steps: replacing the pixel value of the Pj position with Qj to form a dense image;

the specific process of extracting the secret information in the step 6) is as follows: generating L random integer pairs X1 and X2 according to an agreed pseudo-random number generation method, taking out a pixel value Qj corresponding to the position of a received image Pj, and if the Qj is more than or equal to 128, setting the information Sj to 1; if Qj <128, Sj ═ 0;