JPH10304323A - Method for multiplexing and extracting information and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a picture, to make multiplexed information resistant to a compressing processing, and to extract information by means of multiplexing information for components in a relatively low frequency area through the use of orthogonal conversion at the time of multiplexing information to a moving image. SOLUTION: A picture resolution processing part 5 resolves an inputted moving image 2 into a static image in each frame, and resolves each static image into (n)×(n) ((n) is the power of 2) block images 7, and successively transmits them to an information multiplexing processing part 6. The information multiplexing processing part 6 operates the (n)×(n) orthogonal conversion of the picture value information, and changes an orthogonal conversion coefficient value selected by one to one mapping from a random number generated from the initial value of a random number, which is part of an information multiplexing parameter, by using frequency component variation width which is also one part of the information multiplexing parameter. Then, sub-information being one part of the information multiplexing parameter is multiplexed, and the (n)×(n) inverse orthogonal conversion is operated for an orthogonal conversion matrix of multiplexed information, and a moving image is reconstituted from each (n)×(n) size image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for multiplexing information into a digital moving image so that the information is multiplexed so as not to be perceived by human perception, and multiplexed in secret to the moving image. The present invention relates to a method and apparatus for extracting extracted information.

[0002]

2. Description of the Related Art Today, a technique for multiplexing digital information with other information so as not to be perceived by human perception is to secretly multiplex copyright information, a user ID and the like into information contents. It is widely used for copyright protection of digital information contents and for preventing illegal duplication.

However, the conventional technique has a problem that multiplexed information is easily erased by compression processing such as lowering the bit rate of a moving image. Especially in irreversible compression, by removing pixel information more greatly in a flat area than in a complex area of an image,
Since the sub-information is more easily erased, there has been a problem that when irreversible compression is performed on an image having many flat portions, reading of the sub-information fails. Also, there is a problem that it is difficult to perform multiplexing because the flat portion is relatively easily perceived by humans.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image quality and compression processing which is a problem of the conventional information multiplexing technique which is not perceived by humans. In addition, the multiplexed information can withstand the compression processing and the information can be extracted.

[0005]

In order to achieve the above object, according to the present invention, when multiplexing information into a moving image, information is multiplexed into components in a relatively low frequency region using orthogonal transform. By performing orthogonal transformation with a block size larger than the block size used for information compression and performing information multiplexing, resistance to information compression is provided.

More specifically, when multiplexing another piece of sub-information in a digital moving image, a moving image and information multiplexing parameters are input, the moving image is decomposed into each still image, and each still image is converted into n still images.
× n (n is a power of 2) size image, and each n × n
For an image of a size, the pixel value information is subjected to n × n orthogonal transformation of the image value information, and orthogonality selected in a one-to-one mapping from random numbers generated using initial values of random numbers that are part of information multiplexing parameters. A transform coefficient value is changed by using a frequency component change width that is a part of the information multiplexing parameter, and the sub-information that is a part of the information multiplexing parameter is multiplexed. Is subjected to n × n inverse orthogonal transform, and a moving image is reconstructed from the respective images of n × n size.

When extracting sub-information from an information-multiplexed moving image, the information-multiplexed moving image is similarly decomposed into still images, and each still image is decomposed into an n × n size image. For each nxn size image, pixel information is nxn
The orthogonal transform is performed, and from the orthogonal transform coefficient value selected in a one-to-one mapping from a random number generated using the same initial value of the random number used at the time of information multiplexing, the frequency used at the time of information multiplexing is obtained. Information extraction is performed using the component change width to extract the multiplexed sub-information and reconstruct it.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First, the process of multiplexing information into an image will be described. FIG. 1 is a schematic diagram of an input / output relationship of an information multiplexing device according to the present invention. The information multiplexing apparatus 1 receives an original image (main information) 2 of a moving image and an information embedding parameter (information multiplexing parameter) 3 and outputs an information multiplexed image 4. Information embedding parameter 3 is the initial value of the random number,
It consists of frequency component change width information and information to be multiplexed (sub information).

FIG. 2 is an overall configuration diagram of the information multiplexing apparatus 1. The information multiplexing apparatus 1 includes an image decomposition processing unit 5, an information multiplexing processing unit 6, and an image reconstruction processing unit 7. Hereinafter, each processing unit will be sequentially described.

<Image Decomposition Processing Unit 5> FIG. 3 is a diagram showing an outline of the processing of the image decomposition processing unit 5. Image decomposition processing unit 5
Decomposes an input moving image 2 into still images for each frame, further decomposes each still image into n × n (n is a power of 2) block images 7, and sequentially multiplexes the information Send to 6.

[0011] Depending on the size of the image, the end portion may be nx
In some cases, the size may not be n, but in this case, a portion less than the n × n size other than the half-sized remaining image is interpolated with the average pixel value to obtain the n × n And sends it to the information multiplexing processing section 6 (FIG. 3 (a)). As another method, an nxn image may be created by repeating a symmetric image (FIG. 3B).

<Information Multiplexing Processing Unit 6> FIG. 4 is a detailed block diagram of the information multiplexing processing unit 6. Information multiplex processing unit 6
Receives the information embedding parameter 3 and the n × n block image 7, outputs the information multiplexed n × n block image 27, and sends it to the image reconstruction processing unit 7. Hereinafter, the operation of the information multiplexing processing unit 6 will be described in detail.

The information embedding parameter 3 is sent to the input parameter decomposition processing section 8. The input parameter decomposition processing section 8 decomposes the input information embedding parameter 3 and reconstructs and outputs the initial value 10, the frequency component change width 11, and the sub information 12 of the random number. The initial value 10 of the random number is sent to the random number generation processing unit 13, the frequency component change width 11 is sent to the orthogonal transform coefficient change processing unit 14, and the sub information 12 is sent to the sub information buffer 15.

The random number generation processing unit 13 has a random number initial value 10
Is read only once, and a random number 16 is sequentially generated and output for each 1-bit information multiplexing process based on the data.

The sub information buffer 15 stores the sub information 12 in an internal buffer, reads the information one bit at a time by using the internal information read header, and outputs 1-bit sub information 17. FIG. 5 is a conceptual diagram of the sub-information buffer 15.

Various methods are conceivable as a header control method in the sub information buffer, such as a method for moving each one-bit information multiplexing process and a method for moving each one-bit information multiplexing process to each block image. However, this depends on the mounting method of the information multiplexing device. Note that the header control method for reading / writing information from / to the sub-information buffer needs to be implemented by the same method in the information multiplexing device and the information extracting device.

On the other hand, the n × n block image 7 is sent to the orthogonal transformation processing 9. The orthogonal transformation processing unit 9 performs n × n orthogonal transformation of the n × n block image 7 to generate an n × n block orthogonal transformation coefficient matrix 18 and sends the matrix to the orthogonal transformation coefficient change processing unit 14. FIG. 6 is a conceptual diagram of the orthogonal transformation processing unit 9. Since the orthogonal transformation process itself is well known, the details thereof are omitted.

FIG. 7 is a conceptual diagram of the schematic configuration and processing of the orthogonal transform coefficient change processing unit 14. The n × n block orthogonal transform coefficient matrix 18 is stored in an n × n orthogonal transform coefficient matrix buffer 19. The random number 16 is input to the coordinate selection processing unit 20.

The coordinate selection processing unit 20 receives the input random number 1
6, one coefficient is selected from the n × n orthogonal transform coefficient matrix by one-to-one mapping, and the corresponding coordinates 21 are output. The coordinates 21 are stored in a coordinate buffer 23. All are stored in the coordinate buffer 23 for each multiplexing process of each block, and after the multiplexing process of each block, the stored coordinate set 24 is output to the range over avoidance processing unit 25. FIG. 8 is a conceptual diagram of the coordinate buffer 23.

The orthogonal transformation coefficient change processing unit 14 multiplexes the information corresponding to the selected coordinates 21 with the 1-bit sub-information 17 using the frequency component change width 11. The information multiplexing process is performed j times (j is an integer equal to or more than 1 for one block orthogonal transform coefficient matrix and is a parameter determined when the information multiplexing device is implemented. After all the processing is completed, the information multiplexed n × n block orthogonal transform coefficient matrix 22 is output.

Hereinafter, in the i-th frame of the input moving image 2, the 1-bit information multiplexing process on the [h, v] _i block when the upper left of the still image is the [0, 0] _i block This will be specifically described.

The sub-information 12 to be multiplexed is represented by b ₀ b _1.
k-1 (the bit length is k), 1-bit sub-information 17 to be multiplexed into [h, v] _i blocks

[0023]

[Outside 1]

The random number used for multiplexing is

[0025]

[Outside 2]

Let the frequency component change width be range, and let the n × n block orthogonal transform coefficient matrix be [c _{(x, y)} ] _i .

In the coordinate selection processing unit 20, a random number

[0028]

[Outside 3]

From coordinates

[0030]

[Outside 4]

Is selected. Orthogonal transformation coefficient change processing unit 14
Is the orthogonal transform coefficient corresponding to this coordinate in the n × n block orthogonal transform coefficient matrix buffer 19.

[0032]

[Outside 5]

The value of

[0034]

(Equation 1)

[0035]

(Equation 2)

[0036]

(Equation 3)

By changing to 1 bit sub information 1
7 is multiplexed. The coordinates of the multiplexed coefficients are

[0038]

[Outside 6]

The data is sent to the coordinate buffer 23 and stored.

While controlling the sub-information read header of the sub-information buffer 15 in a predetermined manner, the multiplexing process is performed on one block orthogonal transform coefficient matrix in the width information 12 on which it is multiplexed. By repeating j times, which is the number of bits of, the multiplexing process of one block orthogonal transformation matrix is completed.

After the multiplexing process, the information multiplexed n × n block orthogonal transform coefficient matrix 22 (referred to as [c ′ _{(x, y)} ] _i ) and the coordinate set 24 (FIG. 8) are subjected to information multiplexing. The information is transmitted to the range over avoidance processing unit 25 in order to avoid the defective reproduction of the information multiplexed image while maintaining the orthogonal transformation coefficient value and the quality and configuration of the image of the moving image subjected to the information multiplexing.

FIG. 9 is a conceptual diagram of the range over avoiding processing unit 25, and FIG. 10 is a conceptual diagram of the inverse orthogonal transform processing unit 26. The range over avoiding processing unit 25 performs a coordinate set 2 on the n × n block image 27 that has been inverse orthogonally transformed using the input information multiplexed n × n block orthogonal transformation coefficient matrix 26.
4 is performed, and all pixel values are defined in a defined area (for example, 0 to 25 in the case of an 8-bit grayscale image).
The information is corrected so as to fit in 5), and the information multiplexed n × n block image 27 is output. The inverse orthogonal transform unit 26 is configured as shown in FIG.
As shown in FIG. 0, n × n inverse orthogonal transform having the same size as a given block orthogonal transform matrix is performed, and n × n block images are sequentially output.

Here, [c ′ _{(x, y)} ] _i of the information multiplexed n × n block orthogonal transform coefficient matrix 22 input to the range over avoidance processing unit 25 is input to the inverse orthogonal transform processing unit 26. The inverse orthogonally transformed n × n block image 27 is represented by [p ′
_{(x, y)} ] _i .

The coefficient matrix [c ′ _{(x, y)} ] _i input to the range over avoiding processing unit 25 is represented by (0,
0) component (DC component) is changed to the (0,0) component value obtained by performing the n × n orthogonal transformation on all the pixel values of the n × n block image that is the lowest value (for example, the orthogonal transformation DC
Assuming that T, the value is −L _m × n (L _m is an intermediate value of luminance), and a value obtained by setting all component values of all coordinates of the input coordinate set 24 to 0 is already obtained. One is to change the values other than the (0,0) component value and the components of all the coordinates of the input coordinate set 24 to 0,
The n × n images subjected to the inverse orthogonal transform using the inverse orthogonal transform processing unit 26 are referred to as [p1 _{(x, y)} ] _i and [p2 _{(x, y)} ] _i , respectively.

In the range over avoiding processing unit 25, the set

[0046]

(Equation 4)

Then, only when A _i is not an empty set, using [p 1 _{(x, y)} ] _i and [p 2 _{(x, y)} ] _i ,

[0048]

(Equation 5)

By performing the above calculation, an information-multiplexed block image 27 ([p ″ _{(x, y)} ] _i ) is obtained.
Pixel value matrix [p2 _{(x, y)]} at _i, for smaller pixel values than L _min the large pixel values than L _max may be mixed, this range order avoidance process can not be applied, when performing information multiplexing , Care must be taken not to make the value of the range extremely large.

The information multiplexing processing section 6 performs the above processing on all the block images of all the still images, and outputs each information multiplexed n × n block image 27 to the image reconstruction processing section 7.

<Image Reconstruction Processing Unit 7> FIG. 11 is a conceptual diagram of an input / output image in the image reconstruction processing unit 7. The image reconstruction processing unit 7 obtains the information multiplexed image 4 by connecting the input information multiplexed n × n block images and restoring the image into a still image and further a moving image.

Next, information extraction processing from an information multiplexed image will be described. FIG. 12 is a schematic diagram of the input / output relationship of the information extraction device according to the present invention. Information extraction device 28
Receives the information multiplexed image (main information + sub information) 29 and the information extraction parameter 30 and outputs the sub information 31 multiplexed in the image 29. Information extraction parameter 3
0 is the initial value of the random number of the information multiplexing key used when the information multiplexed image 29 was created and the frequency component change width.

FIG. 13 is an overall block diagram of the information extracting device 28. The information extraction device 28 includes an image decomposition processing unit 32
And an information extraction processing unit 33 and a sub-information reconstruction processing unit 34. Hereinafter, each processing unit will be sequentially described.

<Image decomposition processing section 32> Image decomposition processing 32
Is performed by the image decomposition processing unit 5 used in the information multiplexing apparatus 1.
The information multiplexed image 29 is decomposed into still images for each frame, and each still image is further divided into n ×
The image is decomposed into n (n is a power of 2) block images and sequentially sent to the information extraction processing unit 33.

The image decomposing unit 32 includes the information multiplexing device 1
It is necessary to implement so as to decompose an image with the same size as the image decomposing process 6 of. It is also necessary to process a halfway part of the edge of the image as shown in FIG.

<Information Extraction Processing Unit 33> FIG. 14 is a detailed configuration diagram of the information extraction processing unit 33. Information extraction processing unit 33
Receives the information extraction parameter 30 and the information-multiplexed block image 35 as inputs, extracts the sub-information multiplexed in each block image one bit at a time, and This is sent to the configuration processing unit 34. Hereinafter, the operation of the information extraction processing unit 33 will be described in detail.

The information extraction parameter 30 is sent to the input parameter decomposition processing unit 36. Input parameter decomposition processing unit 36
Decomposes the input information extraction parameter 30 and constructs and outputs an initial value 38 of random number and a frequency component change width 39, respectively. The initial value 38 of the random number is sent to the random number generation processing unit 40.
The frequency component change width 39 is determined by the in-block information extraction processing unit 41.
To each of them.

On the other hand, the information multiplexed n × n block image 35 is sent to the orthogonal transformation processing unit 37. The orthogonal transformation processing unit 37 is a part of the information multiplexing processing unit 6 of the information multiplexing device 1.
Performs the same processing as the orthogonal transformation processing unit 9 used in
× n block image 7 is subjected to nxn orthogonal transformation to generate nx
The n-block orthogonal transformation coefficient matrix 42 is sent to the in-block information extraction processing unit 41.

The random number generation processing unit 40 calculates the initial value 38 of the random number.
Is read only once, and a random number 43 is sequentially generated and output for each 1-bit information extraction process based on this. The random number generation processing unit 40 on the information extraction processing side and the random number generation processing unit 13 on the information multiplexing processing side need to be mounted so that the same random number is output in the same order when the same initial value of the random number is input. is there.

FIG. 15 is a block diagram showing a block information extraction processing section 41.
It is a conceptual diagram of a schematic structure and a process of. The n × n block orthogonal transform coefficient matrix 42 is stored in an n × n orthogonal transform coefficient buffer 44. The random number 43 is input to the coordinate selection processing unit 45.

The coordinate selection processing section 45 performs the same processing as the coordinate selection processing section 20 used in the orthogonal transformation coefficient change processing section 14 of the information multiplexing processing section 6. That is, the coordinate selection processing unit 45 on the information extraction processing side and the coordinate selection processing unit 20 on the information multiplexing processing side need to be mounted so as to output the same coordinates when the same random number is input.

The in-block information extraction processing section 41 has n × n
Coordinate selection processing unit 4 in orthogonal transformation coefficient matrix buffer 44
The coefficient corresponding to the coordinate selected by 5 is the frequency component change width 39
To calculate the remainder using
Is output. Information extraction processing is performed j times for one block orthogonal transformation matrix (j is the same number as the number j of bits of sub-information multiplexed into each block orthogonal transformation coefficient matrix implemented in the information multiplexing processing). Then, the multiplexed 1-bit sub information 46 is sequentially output.

As the number of times of extraction of each bit of the multiplexed sub-information increases with the number of times of the information extraction processing, the reliability of the extracted sub-information is improved by performing majority processing or the like on them. .

Hereinafter, the 1-bit information extraction process from the [h, v] _i block when the upper left is the [0,0] _i block in the i-th frame of the information multiplexed image 29 will be specifically described. Will be described.

The sub-information 31 multiplexed in the image 29 is represented by b ₀ b ₁ ... B _k-1 (the bit length is k), [h,
v] One of the sub information multiplexed in the _i block (1
Bit sub-information 46)

[0066]

[Outside 7]

The random number 43 used for information extraction is

[0068]

[Outside 8]

The frequency component change width 39 is set to range, n ×
Let the n-block orthogonal transform coefficient matrix 42 be [c _{(x, y)} ] _i .

In the coordinate selection processing section 45, a random number

[0071]

[Outside 9]

From coordinates

[0073]

[Outside 10]

Is generated. Block information extraction processing unit 4
1 is an orthogonal transform coefficient corresponding to this coordinate in the n × n orthogonal transform coefficient matrix buffer 44

[0075]

[Outside 11]

On the other hand,

[0077]

(Equation 6)

By calculating, the 1-bit sub-information 46 multiplexed in the [h, v] _i block

[0079]

[Outside 12]

Is obtained. This extracted 1-bit sub information 4
6 is sent to the sub-information reconstruction processing unit 34.

<Sub Information Reconstruction Processing Unit 34> FIG. 16 is a conceptual diagram of the processing performed by the sub information reconstruction processing unit 34. The sub-information reconstruction processing unit 34 sequentially inputs the sub-information multiplexed in the block image one bit at a time, and determines each sub-information bit input multiple times by using a method such as majority decision. Is reconstructed. The sub-information reconstruction processing unit 34 receives the 1-bit sub-information 46 and controls the sub-information write header by a predetermined method.

This extraction process is repeated j times for one block orthogonal transformation coefficient matrix, which is the number of bits multiplexed in the matrix, to extract sub-information from one block orthogonal transformation coefficient matrix. Ends.

The above processing is performed on all the block images of all the still images, and is extracted from the information multiplexed image 29 every time the sub-information 31 is obtained or after the processing is completed in all the frames. The sub information 31 is output.

Next, a method of improving the information extraction speed in the information extraction processing will be described below. Information extraction device 2
In the information extraction processing unit 33 in FIG. 8, as shown in FIG. 14, the input n × n block image was once converted into an n × n block orthogonal transformation coefficient matrix using the orthogonal transformation processing block 37. By directly calculating only the information-multiplexed orthogonal transform coefficients from the n × n block image without performing this conversion process, the amount of calculation can be reduced.

FIG. 17 shows the information extraction processing unit 3 which has been sped up.
3 is a diagram showing the configuration of FIG.

The configuration is basically almost the same as that of FIG. 14. The difference is that there is no orthogonal transformation processing unit, and the input of the intra-block information extraction processing unit 50 is that n is directly obtained from the n × n block orthogonal transformation coefficient matrix by n. X This is a change to the n-block image 35. Therefore, hereinafter, only the in-block information extraction processing unit 50 will be described.

FIG. 18 shows a schematic configuration and a conceptual diagram of the processing of the accelerated intra-block information extraction processing section 50. The information extraction processing itself is the same as the operation of the above-mentioned intra-block information extraction processing unit 41, and the different part is that the input n × n block image 35 is stored in the n × n block image buffer 51, and the Using pixel values,
Only the orthogonal transformation coefficient corresponding to the coordinates selected by the coordinate selection processing section 45 is calculated, and the method of extracting the 1-bit sub-information by calculating the coefficient value is the same.

The embodiment of the present invention has been described above.
When j bits of sub-information to be multiplexed on each n × n block image according to the present invention have a certain number, a part of the j-bit sub-information is used as a multiplexed information identification label, thereby improving the reliability of the extracted information. It is possible to get a degree. For example, label information is a ₀ a ₁ ... A _k-1 (each nx
Of the bit number j of the sub-information multiplexed into the n-block image, l (ell) bits are used as label information), and information is extracted, and hamming between the obtained label information portion and the original label information is performed. Let the distance be m (m <l).
At this time, the reliability S of the remaining j−1 bits of sub-information extracted simultaneously with the label information is:

[0089]

(Equation 7)

Can be calculated by By substituting weights for each extracted bit to reconstruct sub-information based on this formula, the accuracy of information extraction is further improved.

Also, by examining the accuracy of label extraction, it is possible to detect the presence or absence of falsification of a moving image, which is the main information. Allows information to be extracted.

The range used for information multiplexing may be changed for each individual block in view of the characteristics of the block image. For example, the entropy of the pixel value of the block image is calculated, and the range is changed according to the value. As described above, by devising the changed frequency component position and the frequency component change width obtained by multiplexing the sub information, information multiplexing can be performed so that a human cannot perceive, and the sub information (image) due to deterioration of the main information (image) can be obtained. Multiplexed information)
Can be controlled with respect to the deterioration. If there is no key information used at the time of information multiplexing, sub-information cannot be extracted.

[0093]

By using the method and the apparatus of the present invention in, for example, a copyright protection system, it is difficult to improve the quality of digital information contents and to strengthen copyright protection measures as compared with the conventional method. Thus, it is possible to measure the bottom-up of the borderline between the quality of the multiplexed information and the survival rate of the multiplexed information, which have a trade-off relationship. That is, information multiplexing can be performed so as to be hardly affected by quantization due to image compression technology used in recent years, and information multiplexing is performed by performing orthogonal transformation with a block size larger than the block size used for information compression.
The effect on the image (image quality deterioration) can be suppressed. Then, when decomposing an image into n × n size, by setting n to a power of 2, it is possible to apply a high-speed orthogonal transformation algorithm, and it is also possible to extract sub-information during reproduction of a moving image.

Although the embodiment is directed to only the luminance component when the image is in the YUV format, the present invention is also applicable to the color difference component. The same applies to the RGB image format, and the same algorithm can be applied to each of R, G, and B. By applying these methods, it is possible to multiplex more information,
Further, by making the information to be multiplexed into each component the same, it is also possible to use the information to detect the presence or absence of tampering with the image and the multiplexed information.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an input / output relationship of an information multiplexing device according to the present invention.

FIG. 2 is an overall configuration diagram of an information multiplexing device.

FIG. 3 is a diagram illustrating an outline of a process of an image decomposition processing unit.

FIG. 4 is a detailed configuration diagram of an information multiplexing processing unit.

FIG. 5 is a conceptual diagram of a sub information buffer.

FIG. 6 is a conceptual diagram of an orthogonal transform coefficient processing unit.

FIG. 7 is a conceptual diagram of an orthogonal transform coefficient change processing unit.

FIG. 8 is a schematic diagram of a coordinate buffer.

FIG. 9 is a conceptual diagram of a range over avoidance processing unit.

FIG. 10 is a conceptual diagram of an inverse orthogonal transform processing unit.

FIG. 11 is a conceptual diagram of an image reconstruction processing unit.

FIG. 12 is a schematic diagram of an input / output relationship of the information extraction device according to the present invention.

FIG. 13 is an overall configuration diagram of an information extraction device.

FIG. 14 is a detailed configuration diagram of an information extraction processing unit.

FIG. 15 is a conceptual diagram of an intra-block information extraction processing unit.

FIG. 16 is a conceptual diagram of a sub-information reconstruction processing unit.

FIG. 17 is a conceptual diagram of an information extraction processing unit which has been sped up;

FIG. 18 is a conceptual diagram of an accelerated intra-block information extraction processing unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 information multiplexing device 2 original image (main information) 3 information embedding parameter (information multiplexing parameter) 4 information multiplexed image 5 image decomposition processing unit 6 information multiplexing processing unit 7 image reconstruction processing unit 29 information multiplexed Image (main information + sub information) 30 information extraction parameter 31 sub information 32 image decomposition processing unit 33 information extraction processing unit 34 sub information reconstruction processing unit

Claims (8)

[Claims] 1. A method for multiplexing another piece of sub-information in a digital moving image, wherein a moving image and information multiplexing parameters are input, the moving image is decomposed into still images, and each still image is
The image is decomposed into images of size n (n is a power of 2), and for each image of size n × n, the pixel value information is converted
The orthogonal transform is performed, and an orthogonal transform coefficient value selected in a one-to-one mapping from a random number generated using an initial value of a random number that is a part of the information multiplexing parameter is changed to a frequency component that is a part of the information multiplexing parameter Changing using the width, multiplexing the sub-information that is a part of the information multiplexing parameter, performing n × n inverse orthogonal transform on the orthogonally transformed matrix subjected to the information multiplexing, An information multiplexing method characterized by reconstructing a moving image. 2. The information multiplexing method according to claim 1, wherein after performing information multiplexing processing on each of the n × n block images, the pixel values of the block image are set so that the pixel values of the image fall within the range. An information multiplexing method characterized in that orthogonal transform coefficients other than information-multiplexed orthogonal transform coefficient values are changed with their average values as the center. 3. The information multiplexing method according to claim 1, wherein a part of the sub information simultaneously multiplexed in each of the n × n size images is used as a multiplexed information identification label. Information multiplexing method. 4. A method for extracting sub-information from an information multiplexed moving image according to the information multiplexing method according to claim 1, wherein the information multiplexed moving image is decomposed into respective still images,
Each still image is decomposed into n × n size images, and for each n × n size image, pixel value information is subjected to n × n orthogonal transformation,
From the orthogonal transform coefficient values selected in a one-to-one mapping from random numbers generated using the same initial values of random numbers used in information multiplexing, the frequency component change width used in information multiplexing is used. An information extraction method, extracting multiplexed sub-information and reconstructing the multiplexed sub-information. 5. The information extracting method according to claim 4, wherein
Omit the n × n orthogonal transform, and extract 1
An information extraction method characterized by extracting sub-information at high speed by calculating only orthogonal transform coefficient values selected by one-to-one mapping. 6. The information extraction method according to claim 4, wherein when the multiplexed information identification label is added to the information-multiplexed image, the original multiplexed information identification label and the extracted multiplexed information identification label are added. An information extraction method characterized in that the reliability of extracted sub-information is calculated using the Hamming distance, and the reliability of each bit constituting the extracted sub-information is used as a weight. 7. A means for inputting an initial value of a digital moving image and a random number, a frequency component conversion width, and information multiplexing parameters of sub information, decomposing a moving image into still images, and converting each still image to n
Means for decomposing the image into an image having a size of × n (n is a power of 2);
For each n × n size image, pixel value information is subjected to n × n orthogonal transformation, and an orthogonal transformation coefficient value selected in a one-to-one mapping from random numbers generated using initial values of random numbers is calculated using a frequency component change width. Means for multiplexing the sub-information by changing the information and performing n × n inverse orthogonal transform on the orthogonally multiplexed matrix subjected to the information multiplexing, and reconstructing a moving image from the respective n × n-size images subjected to the inverse orthogonal transform. An information multiplexing device comprising: 8. A means for inputting an information multiplexed moving image and an information extraction parameter of an initial value of a random number and a frequency component change width, decomposing the information multiplexed moving image into still images, and converting each still image to n A means for decomposing the image into × n size images, and each nx
For an n-size image, pixel value information is subjected to n × n orthogonal transformation, and multiplexing is performed using a frequency component change width from orthogonal transformation coefficient values selected in a one-to-one mapping from random numbers generated using initial values of random numbers. Means for extracting the converted information, and each nx
means for reconstructing information extracted from n images.