CN115550518A - Reversible information hiding method and system based on self-adaptive pixel block division - Google Patents
Reversible information hiding method and system based on self-adaptive pixel block division Download PDFInfo
- Publication number
- CN115550518A CN115550518A CN202211213022.7A CN202211213022A CN115550518A CN 115550518 A CN115550518 A CN 115550518A CN 202211213022 A CN202211213022 A CN 202211213022A CN 115550518 A CN115550518 A CN 115550518A
- Authority
- CN
- China
- Prior art keywords
- pixel
- pixel block
- block
- carrier image
- information
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
- H04N1/32144—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
- H04N1/32149—Methods relating to embedding, encoding, decoding, detection or retrieval operations
- H04N1/32288—Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
- H04N1/32144—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
- H04N1/32149—Methods relating to embedding, encoding, decoding, detection or retrieval operations
- H04N1/32347—Reversible embedding, i.e. lossless, invertible, erasable, removable or distorsion-free embedding
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Editing Of Facsimile Originals (AREA)
Abstract
The invention discloses a reversible information hiding method and a reversible information hiding system based on self-adaptive pixel block division, wherein the method comprises the following steps: performing anti-overflow operation on the parts of the pre-selected carrier image except the first line to obtain a processed carrier image; based on a self-adaptive pixel block division method, pixel block division is carried out on the processed carrier image by utilizing the size of a preset pixel block; based on the carrier image after dividing the pixel blocks, positioning the position of the pixel to be embedded in each pixel block, and calculating the complexity of each pixel block; acquiring a prediction error of a maximum value pixel to be embedded and a minimum value pixel to be embedded in each pixel block, and embedding information to be transmitted based on the prediction error; the auxiliary information required for restoring the carrier image and for extracting the information is embedded in the first row of pixels of the processed carrier image. The invention can improve the embedding performance of the reversible information hiding algorithm and verifies the effectiveness of the method through experiments.
Description
Technical Field
The invention belongs to the technical field of information safety, relates to the field of reversible information hiding based on airspace ground, and particularly relates to a reversible information hiding method and system based on self-adaptive pixel block division.
Background
Reversible information hiding is an advanced information security technology, secret information can be embedded into an open carrier image, so that the secret information is invisible and the existence of the secret information is unknown, an attacker has no way to attack, information stealing in the transmission process is avoided, and data can be subjected to secret communication on the premise of not being discovered; in addition, the receiving party can recover all the secret information and the complete carrier image without loss; reversible information hiding techniques are often applied in areas sensitive to carrier image quality, including military, aerospace, financial, medical, and the like.
Two main performance indexes for measuring the quality of the reversible information hiding algorithm are carrier distortion and embedding capacity, wherein the carrier distortion refers to the loss of image quality before and after a carrier image is embedded with secret information, and the embedding capacity refers to the total amount of the secret information capable of being hidden in one carrier image. In order to reduce carrier distortion, it has been proposed by researchers to embed secret information in the pixels with the largest number of pixel values of the carrier image, so that the distortion of each pixel value is at most 1, and the overall distortion of the carrier is significantly reduced, but this method has a small embedding capacity and has a great correlation with the content of the carrier image itself. In order to increase the embedding capacity, researchers have proposed that four-neighborhood pixels of each pixel are used for predicting the pixel and embedding secret information into carrier prediction errors, but the method has low prediction accuracy and causes large carrier distortion.
At present, researchers propose that secret information is respectively predicted and embedded after carrier images are partitioned, and a good comprehensive effect is obtained.
Disclosure of Invention
The present invention is directed to a reversible information hiding method and system based on adaptive pixel block partitioning, so as to solve one or more of the above-mentioned technical problems. The method provided by the invention can solve the technical problem that the reversible information hiding performance is limited by an inefficient blocking method in the prior art, can increase the number of blocks, increases the embedding capacity, reduces the carrier distortion and can improve the hiding performance of reversible information hiding.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a reversible information hiding method based on self-adaptive pixel block division, which comprises the following steps:
The method of the invention is further improved in that the method also comprises the following steps:
and 5, acquiring a plurality of preset pixel block sizes, repeating the steps 2 to 4 based on each preset pixel block size, comparing the distortion sizes of the images containing the dense carriers under different preset pixel block sizes, and selecting the image containing the dense carrier with the minimum distortion compared with the original image containing the dense carrier as a final image containing the dense carrier.
The method of the invention is further improved in that the step 2 specifically comprises the following steps:
step 2.1, setting a label graph with the same size as the processed carrier image without the first row of pixels, wherein all pixel values in the label graph are initially 0; using the given pixel block size of h × w, starting to frame a pixel block from the upper left corner of the processed carrier image, locating the minimum pixel and the maximum pixel of the pixel block, calculating the complexity value of the pixel block, setting the pixel values of the positions of all pixels of the pixel block in the carrier image corresponding to the processing in the label map to 1, and skipping to execute the step 2.2;
step 2.2, moving the pixel block selected by the frame in the processed carrier image from the current position to the right by a pixel distance, taking the pixel block at the moment as a temporary pixel block, and positioning the minimum pixel and the maximum pixel of the temporary pixel block; if the pixel value of the position corresponding to the minimum pixel and the maximum pixel in the label graph is 0, skipping to execute the step 2.3, otherwise skipping to execute the step 2.2; if the pixel block exceeds the right boundary of the processed carrier image after moving, skipping to execute the step 2.4;
step 2.3, determining the current pixel block as an available block, calculating the complexity of the current pixel block, setting the pixel values of the positions of all pixels of the current pixel block in the carrier image corresponding to the processed marking image to be 1, and skipping to execute the step 2.2;
step 2.4, setting the pixel value of the position in the mark map corresponding to the range which can not be selected to be 1; if the 0-value pixels above h lines still exist in the label image, the pixel block is moved down by h lines and moved left to a position exceeding the left boundary of the image by one pixel on the left side, and then the step 2.2 is executed by skipping; if the 0-value pixels in the label map are less than h rows, setting all the pixel values with the residual value of 0 in the label map as l, and ending the self-adaptive blocking process.
A further development of the process according to the invention consists in that, in step 3,
the step of locating the position of the pixel to be embedded in each block of pixels comprises: for a pixel block, each pixel value is obtained according to the raster scanning order to obtain a pixel value sequence { p 1 ，p 2 ，…，p h×w }; arranging the pixel value sequence from small to large to obtain a sequence { p after sequencing σ(1) ，p σ(2) ，…，p σ(h×w) In the formula, σ: {1,2, …, hxw } → {1,2, …, hxw } is a one-to-one ordered mapping, resulting in p σ(1) ≤p σ(2) ≤…≤p σ(h×w) (ii) a Wherein, in p σ(i) ＝p σ(j) When sigma (i) < sigma (j), i < j, i, j is belonged to {1,2, …, hxw } is the serial number of the pixel in the sorted pixel value sequence; minimum pixel p σ(1) And the maximum pixel p σ(h×w) A possible pixel to be embedded;
when calculating the complexity of each pixel block, the complexity calculation expression of the pixel block is C = p σ(h×w-1) -p σ(2) ；
Obtaining the prediction error of the maximum value pixel to be embedded and the minimum value pixel to be embedded in each pixel block, wherein the process of embedding the information to be transmitted based on the prediction error comprises the following steps: sequentially accessing each pixel block in the carrier image obtained in the step 2 after the pixel blocks are divided, comparing a preselected complexity threshold T with the complexity C of each pixel block, skipping the current block if C is greater than T, calculating the prediction error of the pixel to be embedded of the pixel block if C is less than or equal to T, and embedding the secret information.
The method of the invention is further improved in that, in the process of acquiring the prediction error of the maximum value pixel to be embedded and the minimum value pixel to be embedded in each pixel block in the step 3,
maximum pixel p σ(h×w) Is predicted by the prediction error PE max The calculation of (a) is that,
in the formula, u and v are the spatial position serial numbers of the maximum pixel and the second-largest pixel in the block;
embedding or shifting the pixel according to the value of the prediction error, wherein the expression is,
wherein b ∈ {0,1} is a secret information bit,
is the maximum pixel value in the embedded block;
minimum pixel p σ(1) Is predicted by the prediction error PE min The calculation of (a) is that,
in the formula, s and t are the spatial position serial numbers of the minimum pixel and the secondary minimum pixel in the block;
embedding or shifting the pixel according to the value of the prediction error, wherein the expression is,
trying to embed each pixel block in sequence; for each block of pixels, first try on the maximum value p σ(h×w) Embedding and trying to obtain the minimum value p σ(1) Embedding is performed until the secret information is completely embedded or there are no available pixels.
The method of the invention is further improved in that the step 4 specifically comprises:
for a carrier image of size H x W, the first line of which is recorded before
The least significant bit of each pixel is merged into the secret information;
the first row of the original
The least significant bit is replaced with side information; the auxiliary information includes: the pixel block sizes h and w occupy 2 × 2=4 bits; a complexity threshold T, which occupies 8 bits; last position of embedding P end Occupied
A bit; length l of compressed location map CLM CLM Occupied
A bit; in the formula (I), the compound is shown in the specification,
indicating rounding up.
The method of the invention is further improved in that the method further comprises decoding after the step 4;
the decoding step includes:
before reading the first row
Obtaining each parameter embedded by secret information; the embedded parameters include the pixel block sizes h and w used, the complexity threshold T, and the last position P of the embedding end And length l of the compressed location map CLM CLM ；
According to the obtained embedded parameters, partitioning the image according to the same self-adaptive partitioning method as the embedding method, determining the position of the pixel to be extracted of each pixel block and calculating the complexity of the pixel block; according to the complexity threshold and the complexity value of each pixel block, each pixel block is guided to carry out decoding operation or skipping operation until the most embedded pixel block is decodedRear position P end ；
Corresponding to the least significant bit of the first row in the secret information to be decoded
Bit before the first line
Replacing the least significant bit of the pixel of (a); will correspond to l of CLM CLM Extracting the secret information of the bit, decompressing the secret information to obtain LM, and restoring the edge pixel value by utilizing the LM.
The invention provides a reversible information hiding system based on self-adaptive pixel block division, which comprises:
the preprocessing module is used for performing anti-overflow operation on the parts of the preselected carrier image except the first line to obtain a processed carrier image; acquiring position map information recording an overflow position based on the pre-selected carrier image;
the pixel block dividing module is used for carrying out pixel block division on the obtained processed carrier image by utilizing the size of a preset pixel block based on a self-adaptive pixel block dividing method to obtain the carrier image after the pixel block is divided;
the prediction and embedding module is used for positioning the position of a pixel to be embedded in each pixel block based on the obtained carrier image after the pixel blocks are divided, and calculating the complexity of each pixel block; acquiring a prediction error of a maximum value pixel to be embedded and a minimum value pixel to be embedded in each pixel block, and embedding information to be transmitted based on the prediction error;
the auxiliary information embedding module is used for embedding auxiliary information required by restoring the carrier image and extracting information into the first row of pixels of the processed carrier image; wherein the assistance information comprises the location map information.
The system of the invention is further improved in that the system further comprises:
a decoding module for lossless decoding the embedded information and lossless recovering the carrier image by using the auxiliary information.
Compared with the prior art, the invention has the following beneficial effects:
in the reversible information hiding method provided by the invention, the blocking is carried out by a blocking method based on the self-adaptive moving step length, so that the number of blocks can be increased, the embedding capacity is increased, the carrier distortion is reduced, and the hiding performance of the reversible information hiding can be improved. Further specifically, the invention provides a self-adaptive moving step size blocking method, so that blocks divided by an image can be mutually overlapped, thereby obviously increasing the number of blocks of a carrier image, simultaneously bringing the advantage of increasing embedding capacity in proportion, and reducing carrier distortion caused by embedding secret information under the selection action of a complexity threshold.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; it is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic flowchart of a reversible information hiding method based on adaptive pixel block partitioning according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a tile size 3 × 3 pixel value ordering used in an embodiment of the present invention;
FIG. 3 is a schematic diagram of an adaptive pixel block partitioning method used in embodiments of the present invention;
FIG. 4 is a diagram illustrating the number of blocks obtained by the adaptive pixel block partition method used in the embodiments of the present invention for different pixel block sizes compared with the number of blocks obtained by the conventional method;
FIG. 5 is a diagram illustrating the embedding capacity obtained by the adaptive pixel block partitioning method used in different pixel block sizes in the embodiment of the present invention compared with the embedding capacity of the conventional method;
FIG. 6 is a graph of peak signal-to-noise ratio (PSNR) of a carrier image and an original image as a function of Embedding Capacity (EC) when the algorithm is compared with conventional pixel value ordering prediction in an embodiment of the present invention; fig. 6 (a) is a diagram showing the result on the image Lena, fig. 6 (b) is a diagram showing the result on the image Baboon, and fig. 6 (c) is a diagram showing the result on the image Barbara.
Detailed Description
In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, a reversible information hiding method based on adaptive pixel block partitioning according to an embodiment of the present invention includes the following steps:
In the embodiment of the present invention, to obtain a better effect, the method may further include:
step 5, obtaining a plurality of preset pixel block sizes; repeating steps 2 to 4 based on each preset pixel block size; and comparing the distortion sizes of the dense carrier images under different pixel block sizes, and selecting the dense carrier image with the minimum distortion compared with the original carrier image as the final dense carrier image.
scanning each pixel except the first line of the preselected carrier image according to the raster scanning sequence, setting the k initial value to be 1, and carrying out the following operations on each pixel:
in the formula, p x,y Show seatThe pixel value labeled (x, y), x ∈ [2,H],y∈[1,W]H and W denote the height and width of the carrier image, respectively; LM is a position map, which is a one-dimensional vector for recording the position of pixels whose pixel values are adjusted.
Performing arithmetic compression on the LM to reduce the required memory space and obtain a compressed position map CLM; the CLM is integrated as part of the secret information into the secret information to be embedded.
In step 2 of the embodiment of the invention, the size of the pixel block is set to be h multiplied by w, h belongs to {2,3,4,5} and w belongs to {2,3,4,5}.
In step 2 of the embodiment of the present invention, the method for dividing the adaptive pixel block of the processed carrier image includes the following steps:
step 2.1, a label image of the same size as the processed carrier image not containing the first row of pixels is set, the size of the label image is (H-1) xW, and all pixel values are initially 0. Using the size of a pixel block with a given size, selecting the pixel block from the leftmost corner of the processed carrier image which does not contain the first line of pixels, locating the minimum pixel and the maximum pixel of the block, calculating the complexity value of the block, and setting the pixel values of the positions of all the pixels of the block in the carrier image which is processed correspondingly in the label map to be 1; step 2.2 is performed.
Step 2.2, the pixel block is moved to the right by a pixel distance from the current position, the pixel block at the moment is used as a temporary pixel block, the minimum pixel and the maximum pixel of the temporary pixel block are positioned, if the pixel value of the position corresponding to the minimum pixel and the maximum pixel in the marking image is 0, the step 2.3 is executed, otherwise, the step 2.2 is repeatedly executed; if the pixel block moves beyond the right boundary of the processed carrier image, step 2.4 is performed.
Step 2.3, determining the current pixel block as an available block, calculating the complexity of the available block, and setting the pixel values of the positions of all pixels of the block in the carrier image after corresponding processing in the marking map to be 1; step 2.2 is performed.
And 2.4, setting the pixel value of the position in the mark map corresponding to the range which can not be selected to be 1. If there are more than h lines of 0 pixels in the label map, the pixel block is moved down by h lines and moved left to a position beyond the left boundary of the image by one pixel on the left side, and then step 2.2 is performed. And if the 0-value pixels in the label map are less than h rows, setting all the pixel values with the residual values of 0 in the label map to be 1, and ending the self-adaptive blocking process.
In step 3 of the embodiment of the present invention, for a pixel block, each pixel value in the pixel block is obtained according to the raster scanning order to obtain a pixel value sequence { p } 1 ,p 2 ,…,p h×w Arranging the pixel value sequences in the order from small to large to obtain an ordered sequence { p } σ(1) ,p σ(2) ,…,p σ(h×w) }; wherein sigma: {1,2, …, h × w } → {1,2, …, h × w } is a one-to-one ordering mapping, and the mapping result is p σ(1) ≤p σ(2) ≤…≤p σ(h×w) Wherein, in p σ(i) ＝p σ(j) And sigma (i)<At σ (j), there is i<j, i, j is in the status of {1,2, …, h multiplied by w } is the serial number of the pixel in the sorted pixel value sequence; wherein the smallest pixel p σ(1) And the maximum pixel p σ(h×w) A possible pixel to be embedded.
The complexity calculation method of the pixel block is as follows: c = p σ(h×w-1) -p σ(2) 。
sequentially accessing each block obtained in the step 2, comparing a preselected complexity threshold T with the complexity C of each block, skipping a current block if C is greater than T, calculating the prediction error of a pixel to be embedded of the block if C is less than or equal to T, and embedding secret information into the prediction error, wherein the specific calculation and embedding method is as follows. Note that the original values of the pixels, rather than the embedded values, are all used to access the blocks and perform the calculations.
Maximum pixel p σ(h×w) Is predicted by the prediction error PE max Is calculated as:
PE max ＝p u -p v ′
where u and v are the spatial position indices of the largest pixel and the next largest pixel in the block. Embedding or moving the pixel according to the value of the prediction error, wherein the expression is as follows:
wherein b ∈ {0,1} is a secret information bit,
is the maximum pixel value within the embedded block.
Minimum pixel p σ(1) Is predicted by the prediction error PE min Is calculated as:
PE min ＝p s -p t ，
in the formula, s and t are spatial position sequence numbers of the minimum pixel and the second minimum pixel in the block. Embedding or moving the pixel according to the value of the prediction error, wherein the expression is as follows:
sequentially trying to perform embedding operation on each block according to the sequence of the blocks in the step 2; for each block, first try on the maximum value p σ(h×w) Embedding and trying to obtain the minimum value p σ(1) Embedding is performed until the secret information is completely embedded or there are no available pixels.
for a carrier image of size H x W, the first line of which is recorded before
The least significant bit of each pixel is merged into the secret information;
the first row of the original
The least significant bits are replaced with side information, the side information comprising:
the pixel block sizes h and w occupy 2 x 2=4 bits; a complexity threshold T, which occupies 8 bits; last position of embedding P end Occupied
A bit; length l of compressed location map CLM CLM Occupied
A bit; in the formula (I), the compound is shown in the specification,
indicating rounding up.
The method of the embodiment of the invention also comprises decoding; the decoding step includes:
before reading the first row
Obtaining parameters embedded by secret information, including the sizes h and w of pixel blocks; a complexity threshold T; last position of embedding P end (ii) a Length l of compressed location map CLM CLM 。
And partitioning the image according to the obtained parameters by the same self-adaptive partitioning method as the embedded image, determining the position of the pixel to be extracted of each block and calculating the complexity of the pixel.
According to the complexity and the complexity threshold value and the complexity value of each block, each block is guided to carry out decoding operation or skipping operation until the last position P of embedding is decoded end 。
Corresponding to the least significant bit of the first row in the secret information to be decoded
Bit pair first row
The least significant bit of the pixel of (a) is replaced.
Will correspond to l of CLM CLM Extracting the secret information of the bits, decompressing the secret information to obtain LM, and recovering the original edge pixel value by using the LM.
In the embodiment of the invention, through research on a reversible information hiding technology, it is concluded that the algorithm based on pixel value sorting still has a large improvement space, the number of blocks of a carrier image needs to be further increased, and the conversion efficiency between embedding capacity and carrier distortion needs to be improved. The invention provides a self-adaptive moving step size blocking method, so that blocks divided by an image can be mutually overlapped, the number of blocks of a carrier image is obviously increased, the advantage that the embedding capacity is increased in proportion is brought, and the carrier distortion caused when secret information is embedded is reduced under the selection action of a complexity threshold. In the invention, the self-adaptive moving step size partitioning method is not only suitable for the prediction and embedding method mentioned in the invention, but also suitable for other various methods based on pixel value sequencing, and can increase the embedding capacity and reduce the carrier distortion.
Referring to fig. 1 to fig. 6, a reversible information hiding method for adaptive pixel block partitioning for pixel value ordering according to an embodiment of the present invention includes the following steps:
the method comprises the following steps: performing anti-overflow operation on the parts of the pre-selected carrier image except the first line to obtain a processed carrier image and a position map recording the overflow position;
scanning each pixel except the first line of the preselected carrier image according to the raster scanning sequence, setting the k initial value to be 1, and carrying out the following operations on each pixel:
in the formula (1), p x,y Denotes a pixel value of coordinates (x, y) x ∈ [2,H ]],y∈[1,W]H and W denote the height and width of the carrier image, respectively; LM is a position map, which is a one-dimensional vector for recording the position of pixels whose pixel values are adjusted.
Performing arithmetic compression on the LM to reduce the required memory space and obtain a compressed position map CLM; the CLM is integrated as part of the secret information into the secret information to be embedded.
Step two: for all pixel block sizes within the selected range, the partitioning of the processed carrier image is determined by using an adaptive pixel block partitioning method as shown in fig. 3, and the position of the pixel to be embedded in each block is located and the complexity of each block is calculated as shown in fig. 2.
The size of the pixel block is set to h x w, h belongs to {2,3,4,5} and w belongs to {2,3,4,5}.
For a pixel block, each pixel value is obtained according to the raster scanning order to obtain a pixel value sequence { p 1 ，p 2 ，…，p h×w Arranging the pixel value sequences in the order from small to large to obtain an ordered sequence { p } σ(1) ，p σ(2) ，…，p σ(h×w) }; in the formula, σ: {1,2, …, h × w } → {1,2, …, h × w } is a one-to-one sorted mapping, the mapping result being p σ(1) ≤p σ(2) ≤…≤p σ(h×w) Wherein, in p σ(i) ＝p σ(j) When sigma (i) < sigma (j), i < j, i, j is belonged to {1,2, …, hxw } is the serial number of the pixel in the sorted pixel value sequence; wherein the smallest pixel p σ(1) And the maximum pixel p σ(h×w) A possible pixel to be embedded. The block complexity calculation method is as follows:
C＝p σ(h×w-1) -p σ(2) (2)。
the method for dividing the self-adaptive pixel blocks of the processed carrier image comprises the following steps:
(1) A label image of the same size as the processed carrier image not containing the first row of pixels is set, which size is (H-1) × W, where the pixel values are all initially 0. Using a pixel block of a given size, selecting the pixel block starting from the top left corner of said processed carrier image not containing the first row of pixels, locating the smallest and largest pixels of the block, calculating the complexity value of the block, and setting the pixel values of the positions of all pixels of the block in the processed carrier image in the label map to 1. And executing the process (2) in the step two.
(2) And (3) moving the pixel block from the current position to the right by a pixel distance, taking the pixel block at the moment as a temporary pixel block, positioning the minimum pixel and the maximum pixel of the pixel block, if the pixel value of the position corresponding to the minimum pixel and the maximum pixel in the marking map is 0, executing the process (3) in the step two, otherwise, repeatedly executing the process (2) in the step two. And if the pixel block exceeds the right boundary of the processed carrier image after moving and cannot be selected, executing the process (4) in the second step.
(3) And determining the current pixel block as an available block, calculating the complexity of the available block, and setting the pixel values of the positions of all pixels of the block in the carrier image after the corresponding processing in the marking map to be 1. And executing the process (2) in the step two.
(4) And setting the pixel value of the position in the mark map corresponding to the range which cannot be selected in the frame to be 1. If there are still 0 pixels above h lines in the label map, the pixel block is moved down h lines and moved to the left to the position exceeding the left boundary of the image by one pixel on the left side, and then the process (2) in the second step is executed. And if the 0-value pixels in the label map are less than h rows, setting all the pixel values with the residual values of 0 in the label map as 1, and ending the self-adaptive blocking process.
Step three: for each processed carrier image of which the block is determined, according to the relationship between a preset complexity threshold and the complexity of each block, guiding whether the pixel to be embedded in each block calculates a prediction error for embedding information; and embedding the information to be transmitted into the processed carrier image according to the prediction error obtained by calculation.
And sequentially accessing each block obtained in the second step, comparing a preselected complexity threshold T with the complexity C of each block, skipping the current block if C is greater than T, calculating the prediction error of the pixel to be embedded of the block if C is less than or equal to T, and embedding the secret information into the block, wherein the specific calculation and embedding method is as follows. Note that the original values of the pixels, rather than the embedded values, are all used to access the blocks and perform the calculations.
Maximum pixel p σ(h×w) Is predicted by the prediction error PE max Is calculated as:
PE maX ＝p u -p v (3)
in equation (4), u and v are spatial position indexes of the largest pixel and the second largest pixel in the block. Embedding or moving the pixel according to the value of the prediction error, wherein the expression is as follows:
in formula (5), b ∈ {0,1} is a secret information bit,
is the maximum pixel value within the embedded block.
Minimum pixel p σ(1) Is predicted by the prediction error PE min Is calculated as:
PE min ＝p s -p t (6)
in equation (7), s and t are spatial position numbers of the minimum pixel and the next minimum pixel in the block. Embedding or moving the pixel according to the value of the prediction error, wherein the expression is as follows:
according to the sequence of the blocks in the step twoAttempting to perform an embedding operation for each block; for each block, first try on the maximum value p σ(h×w) Embedding and trying to obtain the minimum value p σ(1) Embedding is performed until the secret information is completely embedded or there are no available pixels.
Step four: embedding auxiliary information required by restoring the carrier image and extracting information into a first row of pixels of the processed carrier image; and selecting a final image containing the dense carrier.
For a carrier image of size H x W, the first line of which is recorded before
The least significant bit of each pixel is merged into the secret information;
the first row of the original
The least significant bits are replaced with side information, the side information comprising:
the pixel block sizes h and w occupy 2 × 2=4 bits; a complexity threshold T, which occupies 8 bits; last position of embedding P end Occupied
A bit; length l of compressed location map CLM CLM Is occupied
The number of bits is one,
indicating rounding up.
And comparing the distortion sizes of the dense carrier images under different pixel block sizes, and selecting the dense carrier image with the minimum distortion compared with the original carrier image as the final dense carrier image.
The performance of the final method can be measured by the embedding capacity-peak signal-to-noise ratio curve, i.e. the quality of the image of the carrier at a certain amount of embedded information.
To sum up, the embodiment of the present invention discloses a reversible information hiding method for adaptive pixel block division for pixel value ordering, which is used for covert communication, and the method includes: carrying out overflow/underflow prevention operation on the carrier image, and recording corresponding information for image recovery; self-adaptive blocking is carried out on the carrier image, the position of a pixel to be embedded is determined, and the complexity of each block is calculated; according to the relation between the complexity and the complexity threshold, sequentially guiding the embedding operation of each pixel; auxiliary information required for decoding is embedded in the image. The invention can improve the embedding performance of the reversible information hiding algorithm based on the pixel value sorting method, and the effectiveness of the method is verified through experiments.
It can be seen from fig. 4,5 and 6 that the reversible information hiding method for adaptive pixel block division for pixel value ordering can effectively improve the embedding capacity and the embedding performance of the pixel value ordering algorithm. Fig. 4 and 5 compare the pixel value sorting method based on the conventional block with the pixel value sorting method based on the adaptive block on the test image Lena, and the number of blocks and the embedding capacity of the blocks under different pixel block sizes. It can be seen that the algorithm of the present invention has a stable improvement in the improvement of embedding capacity.
Fig. 6 shows that the embedding performance of the conventional blocking-based pixel value sorting invertible information hiding method and the algorithm of the present invention on the standard test images Lena, baboon and Barbara, i.e. the corresponding PSNR curve from 5,000 bits to the maximum embedding capacity of the algorithm of the present invention with 1,000 bits as the step length, is significantly improved in both the embedding capacity and the carrier distortion performance.
In summary, an object of the embodiments of the present invention is to provide a reversible information hiding method for adaptive pixel block division for pixel value sorting, so as to solve the problem of limitation on performance of a reversible information hiding algorithm due to low efficiency of a partitioning method in the prior art. The invention provides a self-adaptive moving step size blocking method, so that blocks divided by an image can be mutually overlapped, the number of blocks of a carrier image is obviously increased, the advantage that the embedding capacity is increased in proportion is brought, and the carrier distortion caused when secret information is embedded is reduced under the selection action of a complexity threshold. The invention discloses a reversible information hiding method for self-adaptive pixel block division of pixel value sequencing, which comprises the following steps: the method comprises the following steps: and performing anti-overflow operation on the parts of the pre-selected carrier image except the first line to obtain the processed carrier image and a position map recording the overflow position. Step two: for all pixel block sizes within the selected range, an adaptive pixel block partitioning method is used to determine the partitioning of the processed carrier image, locate the position of the pixel to be embedded in each block, and calculate the complexity of each block. Step three: for each processed carrier image of which the block is determined, according to the relationship between a preset complexity threshold and the complexity of each block, guiding whether the pixel to be embedded in each block calculates a prediction error for embedding information; and embedding the information to be transmitted into the processed carrier image according to the prediction error obtained by calculation. Step four: embedding auxiliary information required for restoring the carrier image and extracting information into a first row of pixels of the processed carrier image; and selecting a final image containing the dense carrier. The invention provides an efficient blocking method to improve the embedding performance of a reversible information hiding algorithm, and the effectiveness of the method is verified through experiments.
The following are embodiments of the apparatus of the present invention that may be used to perform embodiments of the method of the present invention. For details of non-careless mistakes in the embodiment of the apparatus, please refer to the embodiment of the method of the present invention.
In another embodiment of the present invention, a reversible information hiding system for adaptive pixel block partitioning is provided, which includes:
the preprocessing module is used for performing anti-overflow operation on the parts of the preselected carrier image except the first line to obtain a processed carrier image; the position map information used for carrier image recovery is obtained according to the pre-selected carrier image;
the adaptive pixel block dividing module is used for adaptively dividing the processed carrier image except the first line, determining the position of a pixel to be embedded in each block and calculating the complexity of each block;
the prediction and embedding module is used for guiding each pixel to be embedded whether to calculate a prediction error for embedding information or not according to the relation between the complexity and the complexity threshold; embedding secret information into the processed carrier image according to the value of the prediction error obtained by calculation;
the auxiliary information embedding module is used for embedding auxiliary information required by restoring the carrier image and extracting information into the first row of pixels of the processed carrier image; the assistance information includes the location map information;
a decoding module for lossless decoding the embedded information and lossless recovering the carrier image by using the auxiliary information.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (9)
1. A reversible information hiding method based on self-adaptive pixel block division is characterized by comprising the following steps:
step 1, performing anti-overflow operation on parts of a pre-selected carrier image except a first row to obtain a processed carrier image; acquiring position map information recording an overflow position based on the pre-selected carrier image;
step 2, based on a self-adaptive pixel block division method, carrying out pixel block division on the processed carrier image obtained in the step 1 by using a preset pixel block size to obtain a carrier image after the pixel block division;
step 3, based on the carrier image obtained in the step 2 after the pixel blocks are divided, positioning the position of the pixel to be embedded in each pixel block, and calculating the complexity of each pixel block; acquiring a prediction error of a maximum value pixel to be embedded and a minimum value pixel to be embedded in each pixel block, and embedding information to be transmitted based on the prediction error;
step 4, embedding auxiliary information required by restoring the carrier image and extracting information into the first row of pixels of the processed carrier image; wherein the assistance information comprises the location map information.
2. The reversible information hiding method based on adaptive pixel block partitioning according to claim 1, further comprising:
and 5, obtaining a plurality of preset pixel block sizes, repeating the steps 2 to 4 based on each preset pixel block size, comparing the distortion sizes of the images containing the dense carriers under different preset pixel block sizes, and selecting the image containing the dense carrier with the minimum distortion compared with the image containing the original carrier as a final image containing the dense carrier.
3. The reversible information hiding method based on adaptive pixel block partitioning according to claim 1, wherein step 2 specifically comprises the following steps:
step 2.1, setting a label graph with the same size as the processed carrier image without the first row of pixels, wherein all pixel values in the label graph are initially 0; using the given pixel block size of h × w, starting to frame a pixel block from the upper left corner of the processed carrier image, locating the minimum pixel and the maximum pixel of the pixel block, calculating the complexity value of the pixel block, setting the pixel values of the positions of all pixels of the pixel block in the carrier image corresponding to the processing in the label map to 1, and skipping to execute the step 2.2;
step 2.2, moving the pixel block selected by the frame in the processed carrier image from the current position to the right by a pixel distance, taking the pixel block at the moment as a temporary pixel block, and positioning the minimum pixel and the maximum pixel of the temporary pixel block; if the pixel value of the position corresponding to the minimum pixel and the maximum pixel in the label graph is 0, skipping to execute the step 2.3, otherwise skipping to execute the step 2.2; if the pixel block exceeds the right boundary of the processed carrier image after moving, skipping to execute the step 2.4;
step 2.3, determining the current pixel block as an available block, calculating the complexity of the current pixel block, setting the pixel values of all the positions of the pixels corresponding to the current pixel block in the processed carrier image in the label map to be 1, and skipping to execute the step 2.2;
step 2.4, setting the pixel value of the position in the mark map corresponding to the range which can not be selected to be 1; if the pixel with the value of 0 above h still exists in the label map, the pixel block is moved downwards by h, and is moved leftwards to a position exceeding the left boundary of the image by one pixel on the left side, and then the step 2.2 is executed by skipping; and if the 0-value pixels in the label map are less than h rows, setting all the pixel values with the residual values of 0 in the label map as 1, and ending the self-adaptive blocking process.
4. The reversible information concealment method based on adaptive pixel block partitioning according to claim 3, characterized in that in step 3,
the step of locating the position of the pixel to be embedded in each block of pixels comprises: for a pixel block, each pixel value is obtained according to the raster scanning order to obtain a pixel value sequence { p 1 ,p 2 ,…,p h×w }; arranging the pixel value sequence from small to large to obtain a sequence { p after sequencing σ(1) ,p σ(2) ,…,p σ(h×w) In the formula, sigma: {1,2, …, h × w } → {1,2, …, h × w } is one-to-one ordering mapping, and the mapping result is p σ(1) ≤p σ(2) ≤…≤p σ(h×w) (ii) a Wherein, in p σ(i) ＝p σ(j) And sigma (i)<At σ (j), there is i<j, i, j is in the status of {1,2, …, h multiplied by w } is the serial number of the pixel in the sorted pixel value sequence; minimum pixel p σ(1) And the maximum pixel p σ(h×w) A possible pixel to be embedded;
when calculating the complexity of each pixel block, the complexity calculation expression of the pixel block is C = p σ(h×w-1) -p σ(2) ；
Obtaining the prediction error of the maximum value pixel to be embedded and the minimum value pixel to be embedded in each pixel block, wherein the process of embedding the information to be transmitted based on the prediction error comprises the following steps: sequentially accessing each pixel block in the carrier image obtained in the step 2 after the pixel blocks are divided, comparing a preselected complexity threshold T with the complexity C of each pixel block, skipping the current block if C is greater than T, calculating the prediction error of the pixel to be embedded of the pixel block if C is less than or equal to T, and embedding the secret information.
5. The reversible information hiding method based on adaptive pixel block division as claimed in claim 4, wherein in the process of obtaining the prediction error of the maximum value pixel to be embedded and the minimum value pixel to be embedded in each pixel block in step 3,
maximum pixel p σ(h×w) Is predicted by the prediction error PE max The calculation of (a) is that,
PE max ＝p u -p v ，
in the formula, u and v are the spatial position serial numbers of the maximum pixel and the second-largest pixel in the block;
embedding or shifting the pixel according to the value of the prediction error, wherein the expression is,
wherein b ∈ {0,1} is a secret information bit,
is the maximum pixel value in the embedded block;
minimum pixel p σ(1) Is predicted by the prediction error PE min The calculation of (a) is that,
PE mi ＝p s -p t ，
in the formula, s and t are the spatial position serial numbers of the minimum pixel and the secondary minimum pixel in the block;
embedding or shifting the pixel according to the value of the prediction error, wherein the expression is,
trying to embed each pixel block in sequence; for each block of pixels, first try on the maximum value p σ(h×w) Embedding and trying to find the minimum value p σ(1) Embedding is performed until the secret information is completely embedded or there are no available pixels.
6. The reversible information hiding method based on adaptive pixel block partitioning according to claim 5, wherein step 4 specifically includes:
for a carrier image of size H x W, the first line of which is recorded before
The least significant bit of each pixel is merged into secret information;
the first row of the original
The least significant bit is replaced with side information; the auxiliary information includes: the pixel block sizes h and w occupy 2 × 2=4 bits; a complexity threshold T, which occupies 8 bits; last position of embedding P end Occupied
A bit; length l of compressed location map CLM CLM Occupied
A bit; in the formula (I), the compound is shown in the specification,
indicating rounding up.
7. The reversible information hiding method based on adaptive pixel block partitioning according to claim 6, further comprising decoding after step 4;
the decoding step includes:
before reading the first row
Obtaining each parameter embedded by secret information; the embedded parameters include the pixel block sizes h and w used, the complexity threshold T, and the last position P of the embedding end And length l of the compressed location map CLM CLM ；
According to the obtained embedded parameters, partitioning the image according to the same self-adaptive partitioning method as the embedded parameters, determining the position of the pixel to be extracted of each pixel block and calculating the complexity of the pixel block; according to the complexity threshold and the complexity value of each pixel block, each pixel block is guided to carry out decoding operation or skipping operation until the last embedded position P is decoded end ；
Corresponding to the least significant bit of the first row in the secret information to be decoded
Bit before the first line
Replacing the least significant bit of the pixel of (a); will correspond to l of CLM CLM Extracting the secret information of the bits, decompressing the secret information to obtain LM, and recovering the edge pixel value by using the LM.
8. A reversible information hiding system based on adaptive pixel block partitioning, comprising:
the preprocessing module is used for performing anti-overflow operation on the parts of the preselected carrier image except the first line to obtain a processed carrier image; acquiring position map information recording an overflow position based on the pre-selected carrier image;
the pixel block dividing module is used for carrying out pixel block division on the obtained processed carrier image by utilizing the size of a preset pixel block based on a self-adaptive pixel block dividing method to obtain the carrier image after the pixel block is divided;
the prediction and embedding module is used for positioning the position of a pixel to be embedded in each pixel block based on the obtained carrier image after the pixel blocks are divided, and calculating the complexity of each pixel block; acquiring a prediction error of a maximum value pixel to be embedded and a minimum value pixel to be embedded in each pixel block, and embedding information to be transmitted based on the prediction error;
an auxiliary information embedding module for embedding auxiliary information required for restoring the carrier image and extracting information into a first row of pixels of the processed carrier image; wherein the assistance information comprises the location map information.
9. The adaptive pixel block partitioning based reversible information concealment system according to claim 8, further comprising:
a decoding module for lossless decoding the embedded information and lossless recovering the carrier image by using the auxiliary information.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211213022.7A CN115550518A (en) | 2022-09-30 | 2022-09-30 | Reversible information hiding method and system based on self-adaptive pixel block division |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211213022.7A CN115550518A (en) | 2022-09-30 | 2022-09-30 | Reversible information hiding method and system based on self-adaptive pixel block division |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115550518A true CN115550518A (en) | 2022-12-30 |
Family
ID=84731362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211213022.7A Pending CN115550518A (en) | 2022-09-30 | 2022-09-30 | Reversible information hiding method and system based on self-adaptive pixel block division |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115550518A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116308980A (en) * | 2023-02-28 | 2023-06-23 | 淮阴工学院 | Reversible information hiding algorithm based on block optimal dynamic selection |
-
2022
- 2022-09-30 CN CN202211213022.7A patent/CN115550518A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116308980A (en) * | 2023-02-28 | 2023-06-23 | 淮阴工学院 | Reversible information hiding algorithm based on block optimal dynamic selection |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113099067B (en) | Reversible information hiding method and system based on pixel value sequencing prediction and diamond prediction | |
| CN110909591B (en) | Self-adaptive non-maximum suppression processing method for pedestrian image detection by using coding vector | |
| CN105741224A (en) | Reversible watermarking algorithm based on PVO (Pixel Value Ordering) and self-adaptive block segmentation | |
| US11615612B2 (en) | Systems and methods for image feature extraction | |
| CN103632362A (en) | Image matching processing method, device and system | |
| CN115550518A (en) | Reversible information hiding method and system based on self-adaptive pixel block division | |
| CN111539434B (en) | Infrared weak and small target detection method based on similarity | |
| CN111598764A (en) | Big data watermarking method based on artificial intelligence | |
| CN107292803B (en) | Reversible robust digital image watermarking method according with human eye observation rule | |
| CN113570564B (en) | Multi-definition fake face video detection method based on multi-path convolution network | |
| CN111127288B (en) | Reversible image watermarking method, reversible image watermarking device and computer readable storage medium | |
| Bhatnagar et al. | Reversible Data Hiding scheme for color images based on skewed histograms and cross-channel correlation | |
| RU2488881C2 (en) | Method of identifying lines on earth's surface | |
| CN114693951A (en) | RGB-D significance target detection method based on global context information exploration | |
| CN113726974B (en) | Reversible information hiding method, system, equipment and medium | |
| CN113961886B (en) | Reversible information hiding method and system for hyperspectral image | |
| CN108805786B (en) | Steganalysis method and device based on least significant bit matching | |
| Tang et al. | Reversible data hiding based on improved block selection strategy and pixel value ordering | |
| CN112966230A (en) | Information steganography and extraction method, device and equipment | |
| CN117079141B (en) | Mine data intelligent acquisition method and system | |
| CN117974414B (en) | Digital watermark signature verification method, device and equipment based on converged news material | |
| Prabha et al. | An integrated reversible data hiding and compression using enhanced imperialist competitive algorithm optimized side-match vector quantization and modified FoE inpainting | |
| CN114758387B (en) | Lightweight face anti-fraud method and device based on single-frame RGB image | |
| CN112381076B (en) | Method for preprocessing picture in video significance detection task | |
| CN113158838B (en) | Full-size depth map supervision-based face representation attack detection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |