CN105763763B - A kind of image encryption method - Google Patents

Abstract

The invention discloses an image encryption method, which belongs to the field of computer encryption. A face image is acquired through an image acquisition device, and then a password is generated according to the position of any pixel of the face image and its RGB value, and the image is encrypted. The invention can self-adaptively generate a password according to the user's face recognition, has a fast generation speed of the password, and can encrypt an image in combination with the generated password to protect the image. In the image encryption process of the present invention, there is no need to manually set a password for the image, but a unique password is automatically generated after the face recognition device performs face recognition, and the password has a high degree of confidentiality and is compatible with image reorganization. In the later stage of decryption, the image can be decrypted directly according to the password. Compared with the traditional image decryption method, the present invention does not need to reverse the encryption process, which improves the security of image encryption.

Description

An Image Encryption Method

technical field

The invention belongs to the field of computer encryption, in particular to an image encryption method.

Background technique

Network images are works expressed with the help of multimedia deduction and other means using the Internet as a display platform and communication medium. Due to the powerful network media, network images have the advantages of rapid and large-scale transmission, diversity, and interactivity, and have become popular culture. An important part of. But also due to the convenience of network transmission, the intellectual property rights of network images are not easy to be protected. Network piracy and infringement have caused huge losses to authors and copyright owners, and have had a serious impact on the development of network culture, such as seriously affecting the fees charged for photographic works. , so as to inhibit the long-term development of the photography industry. Therefore, media units need to protect their own copyrighted news pictures and material pictures to prevent these pictures from being reprinted or used by other units without compensation.

At the same time, because users sometimes need to share pictures with others through mobile terminals, such as sharing pictures with others through WIFI direct connection, Bluetooth and other technologies; during the sharing process, if the communication data is obtained by a third party, the third party can also obtain the picture content; Even sometimes, the user misuses the user to connect to a third-party user and shares the picture to the third party by mistake (for example, the third-party user is connected to the WIFI direct connection instead of the shared user), resulting in low security of picture sharing.

In order to realize the copyright protection of pictures, most of the existing technologies add watermarks to the pictures, but in the prior art, adding watermarks to the pictures also affects the viewability of the pictures, and some simple watermarks can even be deciphered Restoration is far from achieving the purpose of secure image transmission and effective protection, and the existing technology also has the disadvantage of low work efficiency.

Contents of the invention

In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide an encryption method capable of realizing secure image transmission and effective protection.

To achieve the above object, the present invention provides a method for image encryption, comprising the following steps:

Step 1, obtaining a square human face image with a resolution of a*a by an image acquisition device, where a is a positive integer;

Step 2. Set any pixel point in the face image as P _ij , and obtain the RGB value of pixel point P _ij , where i and j are both positive integers, and 1≤i≤a, 1≤j≤a ;

Step 3, converting the R value, G value and B value of the pixel P _ij into corresponding hexadecimal values;

Determine whether the hexadecimal R value, the hexadecimal G value and the hexadecimal B value of the pixel P _ij reach two digits;

When the hexadecimal R value, hexadecimal G value or hexadecimal B value of the pixel P _ij is less than two digits, a character G is added to the left of the less than two digit hexadecimal value, To form the two-digit R value character string, the two-digit G value character string and the two-digit B value character string of the pixel point P _ij , then perform step 4; when the hexadecimal R value of the pixel point P _ij , the hexadecimal value When the G value and the hexadecimal B value reach two digits, go to step 4 directly;

Step 4, arranging the two-digit R-value character string, the two-digit G-value character string and the two-digit B-value character string of the pixel P _ij from left to right to form a first series string;

Step five, converting i and j into corresponding hexadecimal values;

Determine whether the hexadecimal value of i or the hexadecimal value of j reaches four digits; when the hexadecimal value of i or the hexadecimal value of j is less than four digits, the Add the character G to the left of the hexadecimal value to form a four-digit string of i and a four-digit string of j, and then perform step six; when the hexadecimal value of i and the hexadecimal value of j reach four digits , go to Step 6;

Step 6, adding the four-digit string of j to the left side of the first progression string, and adding the four-digit string of i to the left side of the four-digit string of j to form a second progression string ;

Step 7, dividing the face image into 16*16 square regions Select the area T _m,n where the pixel P _ij is located, where m and n are both positive integers and 1≤m≤16, 1≤n≤16;

Step 8, judge whether there is a character G in the second series of numbers; when the second series of numbers contains the character G, replace the character G in the second series of numbers with 0, and then perform step nine; when the second series of numbers When there is no character G in , perform step nine;

Step 9, setting the penultimate digit of the second series number string to be Q ₁ , and setting the penultimate number of the second series number string to be Q ₂ ;

Convert Q ₁ and Q ₂ to decimal values respectively; calculate Q ₁₁ =Q ₁ +1 to get Q ₁₁ , calculate Q ₂₁ =Q ₂ +1 to get Q ₂₁ ; said 1≤Q ₁₁ ≤16, said 1≤Q _21≤16 ;

calculate Obtain the first target area T _{x, y} ;

Replace T _{m, n} with T _{x, y} ;

Step 10. Replace the first line area with the third line area; replace the second line area with the fourth line area; replace the fifth line area with the seventh line area; replace the sixth line area with the eighth line area area; replace the ninth line area with the eleventh line area; replace the tenth line area with the twelfth line area; replace the thirteenth line area with the fifteenth line area; replace the fourteenth line area The line area is replaced with the sixteenth line area.

By adopting the above technical solution, a password can be adaptively generated according to the user's face recognition, and the generation speed is fast, and the image can be encrypted in combination with the generated password to protect the image.

Preferably, in the step 7, selecting the area T _m,n where the pixel P _ij is located is carried out according to the following steps:

calculate get m, calculate Obtain n; select the region T _m,n according to the values of m and n.

Preferably, in step 1, the acquisition of a square human face image with a resolution of a*a by an image acquisition device is performed in the following steps:

Obtain a face image with a resolution of a*b by an image acquisition device, where a is the number of pixels in the horizontal direction, and b is the number of pixels in the vertical direction;

Determine whether a>b;

When a>b, calculate W ₁ = ab, get the number W ₁ to be added, then add W ₁ pixels with RGB value﹛0,0,0﹜ along the vertical direction, and then perform step 2;

When a<b, calculate W ₂ =ba, get the number W ₂ to be added, then add W ₂ pixels with RGB values﹛0,0,0﹜ along the horizontal direction, and assign the value of b to a , and then perform step two;

When a=b, execute step 2.

The present invention also provides an image decryption method, comprising the following steps:

S1. Divide the encrypted image into 16*16 square areas The area from the first row to the fourth row is the first encryption module, the area from the fifth row to the eighth row is the second encryption module, the area from the ninth row to the twelfth row is the third encryption module, and the area from the thirteenth row to the sixteenth row is The row area is the fourth encryption module;

S2. Receive the password input by the user;

S3, judging whether the password input by the user is a 14-digit string; when the password input by the user is a 14-digit string, execute step S4; when the password input by the user is not a 14-digit string, return to execute step S2;

S4. Determine whether there is a character G in the input password; when the password contains the character G, replace the character G in the password with 0, and then perform step S5; when there is no character G in the password, perform step S5;

S5. Perform region determination and RGB value conversion in parallel;

The region determination is carried out in the following steps:

A1. Extract the 1st to 4th digits of the password from left to right to form the third series and convert it into a decimal value U ₁ ; extract the 5th to 8th digits of the password from left to right to form the fourth series string, and convert it to a decimal value U ₂ ;

Extract the 14th digit of the password from left to right and convert it into a decimal value U ₃ ; extract the 13th digit of the password from left to right and convert it into a decimal value U ₄ ;

A2. Select the area to be replaced T _{r, t} , r, t are positive integers and 1≤r≤16, 1≤t≤16:

calculate get r, calculate Get t; select the area to be replaced T _{r, t} according to the value of r and t;

A3. Calculate U ₃₁ =U ₃ +1 to get U ₃₁ , calculate U ₄₁ =U ₄ +1 to get U ₄₁ ; said 1≤U ₃₁ ≤16, said 1≤U ₄₁ ≤16;

calculate Obtaining the second target region T _p,q ; the 1≤p≤16, the 1≤q≤16;

A4. Select the encryption module corresponding to T _{p, q} , and decrypt the encryption module: replace the first row of the encryption module with the third row of the encryption module, and replace the second row of the encryption module with the encryption module The fourth line of the module is replaced;

A5. Judgment Whether it is located in the same encryption module as T _{p, q} ; when and T _{p, q} are located in the same encryption module, perform step A6; when When T _{p, q} are not in the same encryption module, the The encryption module where it is located is decrypted: the Replace the first line of the encryption module with the third line of the encryption module, and the Replace the second line of the encryption module with the fourth line of the encryption module, and then perform step A6;

A6, replace T _{r, t} with T _{p, q} ;

The RGB value conversion is carried out in the following steps:

Extract the 9th and 10th digits of the password from left to right to form the fifth series and convert it into a decimal value U ₅ ; extract the 11th and 12th digits of the password from left to right to form the sixth series string, and convert it into a decimal value U ₆ ; extract the 13th and 14th digits of the password from left to right to form a seventh progression string, and convert it into a decimal value U ₇ ;

S6. Perform RGB value matching:

Select Pixels 1≤i≤a, 1≤j≤a, and i, j, a are all positive integers; Compare the R value, G value and B value with U ₅ , U ₆ and U ₇ respectively; Is the R value equal to U ₅ , when When the R value of is not equal to U ₅ , end decryption; when When the value of R is equal to U ₅ , the judgment Whether the G value of is equal to U ₆ ; when When the G value of is not equal to U ₆ , end the decryption; when When the G value is equal to U ₆ , judge Whether the B value of is equal to U ₇ ; when When the B value of is not equal to U ₇ , end the decryption; when Whether the value of B is equal to U ₇ , execute step S7;

S7. Determine whether the first encryption module to the fourth encryption module have been decrypted in turn; decrypt the encryption modules that have not been decrypted:

Replace the first line of the undecrypted encryption module with the third line of the encryption module, and replace the second line of the undecrypted encryption module with the fourth line of the encryption module.

The beneficial effects of the present invention are: the present invention can self-adaptively generate a password according to the user's face recognition, the password generation speed is fast, and the image can be encrypted in combination with the generated password to protect the image. In the image encryption process of the present invention, there is no need to manually set a password for the image, but a unique password is automatically generated after the face recognition device performs face recognition, and the password has a high degree of confidentiality and is compatible with image reorganization. In the later stage of decryption, the image can be decrypted directly according to the password. Compared with the traditional image decryption method, the present invention does not need to reverse the encryption process, which improves the security of image encryption.

Detailed ways

The present invention will be further described below in conjunction with embodiment:

An image encryption method, comprising the steps of:

Step 1, obtaining a square human face image with a resolution of a*a by an image acquisition device, where a is a positive integer;

Step 2. Set any pixel point in the face image as P _ij , and obtain the RGB value of pixel point P _ij , where i and j are both positive integers, and 1≤i≤a, 1≤j≤a ;

Step 3, converting the R value, G value and B value of the pixel P _ij into corresponding hexadecimal values;

Determine whether the hexadecimal R value, the hexadecimal G value and the hexadecimal B value of the pixel P _ij reach two digits;

When the hexadecimal R value, hexadecimal G value or hexadecimal B value of the pixel P _ij is less than two digits, a character G is added to the left of the less than two digit hexadecimal value, To form the two-digit R value character string, the two-digit G value character string and the two-digit B value character string of the pixel point P _ij , then perform step 4; when the hexadecimal R value of the pixel point P _ij , the hexadecimal value When the G value and the hexadecimal B value reach two digits, perform step 4;

Step 4, arranging the two-digit R-value character string, the two-digit G-value character string and the two-digit B-value character string of the pixel P _ij from left to right to form a first series string;

Step 5, converting i and j into corresponding hexadecimal values respectively;

Determine whether the hexadecimal value of i or the hexadecimal value of j reaches four digits; when the hexadecimal value of i or the hexadecimal value of j is less than four digits, the Add the character G to the left of the hexadecimal value to form a four-digit string of i and a four-digit string of j, and then perform step six; when the hexadecimal value of i and the hexadecimal value of j reach four digits , go to Step 6;

Step 6, adding the four-digit string of j to the left side of the first progression string, and adding the four-digit string of i to the left side of the four-digit string of j to form a second progression string ;

Step 7, dividing the face image into 16*16 square regions Select the area T _m,n where the pixel P _ij is located, where m and n are both positive integers and 1≤m≤16, 1≤n≤16;

Step 8, judge whether there is a character G in the second series of numbers; when the second series of numbers contains the character G, replace the character G in the second series of numbers with 0, and then perform step nine; when the second series of numbers When there is no character G in , perform step nine;

Step 9, setting the penultimate digit of the second series number string to be Q ₁ , and setting the penultimate number of the second series number string to be Q ₂ ;

Convert Q ₁ and Q ₂ to decimal values respectively; calculate Q ₁₁ =Q ₁ +1 to get Q ₁₁ , calculate Q ₂₁ =Q ₂ +1 to get Q ₂₁ ; said 1≤Q ₁₁ ≤16, said 1≤Q _21≤16 ;

calculate Obtain the first target area T _{x, y} ;

Replace T _{m, n} with T _{x, y} ;

Step 10. Replace the first line area with the third line area; replace the second line area with the fourth line area; replace the fifth line area with the seventh line area; replace the sixth line area with the eighth line area area; replace the ninth line area with the eleventh line area; replace the tenth line area with the twelfth line area; replace the thirteenth line area with the fifteenth line area; replace the fourteenth line area The line area is replaced with the sixteenth line area.

In this embodiment, in the step 7, selecting the area Tm _{, n} where the pixel point P _ij is located is performed according to the following steps:

calculate get m, calculate Obtain n; select the region T _m,n according to the values of m and n.

In this embodiment, in step 1, the acquisition of a square human face image with a resolution of a*a by the image acquisition device is carried out in the following steps:

Obtain a face image with a resolution of a*b by an image acquisition device, where a is the number of pixels in the horizontal direction, and b is the number of pixels in the vertical direction;

Determine whether a>b;

When a>b, calculate W ₁ = ab, get the number W ₁ to be added, then add W ₁ pixels with RGB value﹛0,0,0﹜ along the vertical direction, and then perform step 2;

When a<b, calculate W ₂ =ba, get the number W ₂ to be added, then add W ₂ pixels with RGB values﹛0,0,0﹜ along the horizontal direction, and assign the value of b to a Get the value of a after adding pixels, and then perform step 2;

When a=b, execute step 2.

An image decryption method, comprising the following steps:

S1. Divide the encrypted image into 16*16 square areas The area from the first row to the fourth row is the first encryption module, the area from the fifth row to the eighth row is the second encryption module, the area from the ninth row to the twelfth row is the third encryption module, and the area from the thirteenth row to the sixteenth row is The row area is the fourth encryption module;

S2. Receive the password input by the user;

S3, judging whether the password input by the user is a 14-digit string; when the password input by the user is a 14-digit string, execute step S4; when the password input by the user is not a 14-digit string, return to execute step S2;

S4. Determine whether there is a character G in the input password; when the password contains the character G, replace the character G in the password with 0, and then perform step S5; when there is no character G in the password, perform step S5;

S5. Perform region determination and RGB value conversion in parallel;

The region determination is carried out in the following steps:

A1. Extract the 1st to 4th digits of the password from left to right to form the third series and convert it into a decimal value U ₁ ; extract the 5th to 8th digits of the password from left to right to form the fourth series string, and convert it to a decimal value U ₂ ;

Extract the 14th digit of the password from left to right and convert it into a decimal value U ₃ ; extract the 13th digit of the password from left to right and convert it into a decimal value U ₄ ;

A2. Select the area to be replaced T _{r, t} , r, t are positive integers and 1≤r≤16, 1≤t≤16:

calculate get r, calculate Get t; select the area to be replaced T _{r, t} according to the value of r and t;

A3. Calculate U ₃₁ =U ₃ +1 to get U ₃₁ , calculate U ₄₁ =U ₄ +1 to get U ₄₁ ; said 1≤U ₃₁ ≤16, said 1≤U ₄₁ ≤16;

calculate Obtaining the second target region T _p,q ; the 1≤p≤16, the 1≤q≤16;

A4. Select the encryption module corresponding to T _{p, q} , and decrypt the encryption module: replace the first row of the encryption module with the third row of the encryption module, and replace the second row of the encryption module with the encryption module The fourth line of the module is replaced;

A5. Judgment Whether it is located in the same encryption module as T _{p, q} ; when and T _{p, q} are located in the same encryption module, perform step A6; when When T _{p, q} are not in the same encryption module, the The encryption module where it is located is decrypted: the Replace the first line of the encryption module with the third line of the encryption module, and the Replace the second line of the encryption module with the fourth line of the encryption module, and then perform step A6;

A6, replace T _{r, t} with T _{p, q} ;

The RGB value conversion is carried out in the following steps:

Extract the 9th and 10th digits of the password from left to right to form the fifth series and convert it into a decimal value U ₅ ; extract the 11th and 12th digits of the password from left to right to form the sixth series string, and convert it into a decimal value U ₆ ; extract the 13th and 14th digits of the password from left to right to form a seventh progression string, and convert it into a decimal value U ₇ ;

S6. Perform RGB value matching:

Select Pixels 1≤i≤a, 1≤j≤a, and i, j, a are all positive integers; Compare the R value, G value and B value with U ₅ , U ₆ and U ₇ respectively; Is the R value equal to U ₅ , when When the R value of is not equal to U ₅ , end decryption; when When the value of R is equal to U ₅ , the judgment Whether the G value of is equal to U ₆ ; when When the G value of is not equal to U ₆ , end the decryption; when When the G value is equal to U ₆ , judge Whether the B value of is equal to U ₇ ; when When the B value of is not equal to U ₇ , end the decryption; when Whether the value of B is equal to U ₇ , execute step S7;

S7. Determine whether the first encryption module to the fourth encryption module have been decrypted in turn; decrypt the encryption modules that have not been decrypted:

Replace the first line of the undecrypted encryption module with the third line of the encryption module, and replace the second line of the undecrypted encryption module with the fourth line of the encryption module.

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (3)

1. a kind of image encryption method, it is characterised in that include the following steps：

Step 1: obtaining the square facial image that resolution ratio is a*a by image capture device, a is positive integer；

Step 2: setting in the facial image any one pixel as P_ij, obtain pixel P_ijRgb value, described i, j are Positive integer, and 1≤i≤a, 1≤j≤a；

Step 3: by pixel P_ijR values, G values and B values be respectively converted into corresponding hexadecimal values；

Judge pixel P_ijHexadecimal R values, hexadecimal G values and hexadecimal B values whether reach two；

As pixel P_ijHexadecimal R values, hexadecimal G values or hexadecimal B values less than two when, this less than two A character G is added on the hexadecimal value left side, to form pixel P_ijTwo R values character strings, two G values character strings and two B value character strings, then execute step 4；As pixel P_ijHexadecimal R values, hexadecimal G values and hexadecimal B values reach At two, step 4 is executed；

Step 4: by pixel P_ijTwo R values character strings, two G values character strings and two B values character strings from left to right successively Arrangement form the first series string；

Step 5: i and j are respectively converted into corresponding hexadecimal values；

Whether the hexadecimal value of the hexadecimal value or j that judge i reaches four；When the hexadecimal value of i or the hexadecimal of j When value is less than four, character G is added on the hexadecimal value left side less than four, with formed i four character strings and j four Position character string, then executes step 6；When the hexadecimal value of the hexadecimal value of i and j reaches four, step 6 is executed；

Step 6: four character strings of j to be added to the left side of the first series string, and four character strings of i are added to The left side of four character strings of the j, to form the second series string；

Step 7: the facial image is divided into 16*16 square areaChoose institute State pixel P_ijThe region T at place_{M, n}, m, n are positive integer and 1≤m≤16,1≤n≤16；

Step 8: judging whether there is character G in the second series string；When in the second series string including character G, by the second series string In character G replace with 0, then execute step 9；When there is no character G in the second series string, step 9 is executed；

Step 9: setting the digit last of the second series string as Q₁, set the penultimate of the second series string Number is Q₂；

By Q₁And Q₂It is respectively converted into decimal value；Calculate Q₁₁=Q₁+ 1 obtains Q₁₁, calculate Q₂₁=Q₂+ 1 obtains Q₂₁；Described 1 ≤Q₁₁≤ 16, the 1≤Q₂₁≤16；

It calculatesObtain first object region T_{X, y}；

By T_{M, n}With T_{X, y}It is replaced；

Step 10: the first row region and the third line region are replaced；Second row region is replaced with fourth line region； Fifth line region and the 7th row region are replaced；6th row region is replaced with the 8th row region；By the 9th row area Domain is replaced with the tenth a line region；Tenth row region is replaced with the 12nd row region；By the tenth zone domain with Tenth five-element region is replaced；Ariadne region and the 16th row region are replaced.

2. a kind of image encryption method as described in claim 1, it is characterized in that：The pixel P is chosen in the step 7_ij The region T at place_{M, n}It carries out according to the following steps：

It calculatesM is obtained, is calculatedObtain n；According to the value chosen area T of m and n_{M, n}。

3. a kind of image encryption method as described in claim 1, it is characterized in that：In step 1, obtained by image capture device It is that the square facial image of a*a carries out according to the following steps to take resolution ratio：

The facial image that resolution ratio is a*b is obtained by image capture device, a is the pixel quantity of horizontal direction, and b is Vertical Square To pixel quantity；

Judge whether a>b；

Work as a>When b, W is calculated₁=a-b obtains number W to be increased₁, then vertically add W₁A rgb value Wei ﹛ 0,0, The pixel of 0 ﹜, then executes step 2；

Work as a<When b, W is calculated₂=b-a obtains number W to be increased₂, W is then added in the horizontal direction₂A rgb value Wei ﹛ 0,0, The pixel of 0 ﹜, and the numerical value of b is assigned to a, then execute step 2；

As a=b, step 2 is executed.