JP2002354221A - Image processor, data processor, image and data processing method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the extraction of an electronic water mark is also carried out from an area where the electronic watermark is not embedded and the reliability of the extracted electronic watermark is degraded when the electronic watermark is extracted from an entire image including a blank space produced in the process of image read operation or an area produced by correction of geometrical conversion. SOLUTION: An image processor is provided with a parallel translation extent calculation part 702 which uses a positioning signal to calculate an extent of parallel translation applied to the image, a parallel translation correction part 1301 which generates a corrected image obtained by correcting the extent of parallel translation calculated by the parallel translation extent calculation part 702, an effective area discrimination part 1302 which discriminates the effective area where the existence of electronic watermark is discriminated, and an additional information extraction part 703 which extracts the electronic watermark from the effective area discriminated by the effective area discrimination part 1302.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and a data processing method for extracting secondary information from an image or signal in which secondary information such as a digital watermark is embedded in original image data or signal. The present invention relates to a processing device, a method thereof, and a storage medium.

[0002]

2. Description of the Related Art In recent years, with the rapid development and spread of computers and their networks, various types of information such as character data, image data, and voice data have been digitized.
The digitized data is exchanged via a network. Such digital information is
While it can be stored in a perfect state forever without deterioration due to aging or the like, it can be easily copied, and the protection of the copyright of the digital data is a major problem. Therefore, security techniques for copyright protection are rapidly gaining importance.

[0003] One of such copyright protection techniques is "digital watermarking". This digital watermark embeds the copyright holder's name or purchaser's ID in digital image data, audio data, character data, etc. in a manner that cannot be perceived by humans, and tracks unauthorized use by illegal copying. Technology. In addition to such copyright protection, information is embedded in digital data in advance in such digital watermarks, and information is added to the digital data by ensuring consistency of information according to rules in which the digital data is embedded. It is also applied to technologies such as detecting a tampered position.

[0004] Digital watermarking generally uses a method of embedding watermark information by processing a portion of digital data that is difficult for a human to perceive even if a change is made. For this reason, there is a trade-off between the “quality compared to the original”, “the strength of the digital watermark”, and “the amount of information that can be embedded” of the digital data in which the digital watermark is embedded. Here, the “strength of digital watermark resistance” means that the embedded data can be extracted even after various processing and editing are applied to the digital data in which the digital watermark is embedded. As described above, in order to realize a digital watermark having a higher resistance to various processing and editing, for example, in the case of an image, rotation, scaling,
A method of embedding a signal (generally called a registration signal) for detecting a geometric transformation such as translation has been proposed.

[0005] Even when an image in which such a digital watermark is embedded is subjected to a geometric transformation, the above-mentioned registration signal is analyzed to calculate the geometric transformation added to the image, and the attack is performed. The image in which the received digital watermark is embedded can be corrected to the original geometric state. Therefore, by combining a digital watermark embedding method that is not resistant to geometric transformation of an image and a registration signal, it is possible to extract additional information for extracting a digital watermark after correcting the geometric transformation for the image. become.

[0006]

However, considering a case in which a signal having such a digital watermark embedded therein is subjected to some processing, it is considered that a case where a signal without a digital watermark embedded therein is also included. Can be

FIG. 18 is a diagram showing an example of a digital image in which an image in which a digital watermark is embedded is printed, and the image is further read by a scanner. In the figure, reference numeral 901 denotes an entire image input by the scanner, and 902 denotes an image in which a digital watermark is embedded. In FIG. 18, a large margin is included in addition to the image 902 in which the digital watermark is embedded.

Further, when a geometric transformation such as scaling, rotation, or translation is applied to the digital watermark embedded image as shown in FIG. 19, the primary transformation added to the original image is calculated and the correction is performed. Image 1 shown in FIG.
After obtaining the image 103, the digital watermark is extracted based on the parallel movement amount of the image 1103.

However, conventionally, the printing of the image described above,
Even if there is a region (for example, a hatched portion 1104 in FIG. 20) generated due to the correction of the blank space and the geometrical transformation generated in the process of reading the image, the entire image of the input image 1101 is converted to the electronic image. I have been extracting watermarks. Therefore, when the digital watermark is extracted from the entire read image 1101, the extraction is also performed from the area where the digital watermark is not embedded, which lowers the reliability of the extracted digital watermark.

In addition, at the boundary between a region (for example, a hatched portion 1104 in FIG. 20) generated due to the correction of the geometric transformation and a margin (for example, 1105 in FIG. 20) generated in the process of printing and subsequent image reading, a pixel There are large differences in the values.
This becomes an edge of the image, which may adversely affect the extraction of the additional information. In the process of printing an image and reading an image, there is a possibility that not only an electronic watermark but also a background pattern that hinders the extraction of an electronic watermark exists in an image to be extracted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and for example, after correcting a geometric transformation added to an image or a signal in which secondary information such as a digital watermark is embedded, the secondary conversion is performed. An object of the present invention is to provide an image processing device and a data processing device, a method thereof, and a storage medium capable of extracting highly reliable information by extracting information.

[0012]

In order to achieve the above object, an image processing apparatus according to the present invention has the following arrangement.
That is, an image processing apparatus for extracting secondary information from an image in which a minimum embedding unit including a positioning signal for acquiring secondary information and position information is repeatedly embedded, wherein A geometric transformation calculating unit that calculates a geometric transformation amount added to the image using a matching signal; and a geometric unit that generates a geometric transformation corrected image in which the geometric transformation amount calculated by the geometric transformation calculating unit is corrected. A conversion correction unit, an effective area determination unit that determines an effective area for determining the presence of the subsidiary information in the geometric conversion correction image, and the secondary area from the effective area determined by the effective area determination unit. Extracting means for extracting basic information.

[0013] To achieve the above object, the image processing method of the present invention comprises the following steps. That is, an image processing method for extracting secondary information from an image in which a minimum embedding unit including a positioning signal for obtaining secondary information and position information is repeatedly embedded, wherein A geometric transformation calculating step of calculating a geometric transformation amount added to the image by using a matching signal; and a geometric transformation for generating a geometric transformation corrected image in which the geometric transformation amount calculated in the geometric transformation calculating step is corrected. A correction step, an effective area determination step of determining an effective area for determining the presence of the secondary information in the geometric transformation corrected image, and the secondary area from the effective area determined in the effective area determination step. And extracting an important information.

In order to achieve the above object, an image processing apparatus according to the present invention has the following arrangement. That is, the minimum embedding unit including the alignment information for obtaining the secondary information and the position information is an image processing device for extracting the secondary information from the moving image data repeatedly embedded in each frame. Selecting means for selecting a partial area composed of a plurality of frames from the moving image data; averaged image obtaining means for generating an averaged image in frame units from the partial area; and the positioning signal A geometric transformation calculating means for calculating a geometric transformation added to the averaged image by using a geometric transformation correcting means for generating a geometric transformation corrected image in which the geometric transformation calculated by the geometric transformation calculating means is corrected. Means, an area dividing means for dividing the geometrically transformed corrected image into a plurality of blocks, and a position relating to the position information for each of the plurality of blocks. Positioning signal detecting means for calculating a positioning signal correlation value representing a correlation with a positioning signal, and comparing the positioning signal correlation value for each of the plurality of blocks with a threshold value to determine the presence of the secondary information. An effective area determining means for determining an effective area to be determined, and an extracting means for extracting the secondary information from the effective area determined by the effective area determining means are provided.

[0015] To achieve the above object, the image processing method of the present invention comprises the following steps. That is, the minimum embedding unit including the alignment information for obtaining the secondary information and the position information is an image processing method for extracting the secondary information from the moving image data repeatedly embedded in each frame. A selecting step of selecting a partial area including a plurality of frames from the moving image data; an averaged image obtaining step of generating an averaged image in frame units from the partial area; A geometric transformation calculating step of calculating a geometric transformation added to the averaged image by using a geometric transformation correcting step of generating a geometric transformation corrected image in which the geometric transformation calculated in the geometric transformation calculating step is corrected. An area dividing step of dividing the geometrically transformed corrected image into a plurality of blocks; and a position matching process for the position information for each of the plurality of blocks. An alignment signal detecting step of calculating a positioning signal correlation value representing the correlation between cause signal, the positioning signal correlation value for each of said plurality of blocks is compared with a threshold value,
An effective area determination step of determining an effective area for determining the presence of the secondary information, and an extraction step of extracting the secondary information from the effective area determined in the effective area determination step. It is characterized by the following.

To achieve the above object, the data processing apparatus of the present invention has the following configuration. That is, a data processing device for extracting the secondary information from a signal in which a minimum embedding section including a secondary information and a positioning signal for acquiring position information is repeatedly embedded, the data processing apparatus comprising: A time movement calculating means for calculating a time-direction movement added to the signal using the signal, and a time for generating time-movement correction data obtained by correcting the time-direction movement calculated by the time movement calculating means Movement correction means, an effective area determination means for determining an effective area for determining the presence of the secondary information in the time movement correction data, and the secondary area from the effective area determined by the effective area determination means. Extracting means for extracting basic information.

In order to achieve the above object, the data processing method of the present invention has the following configuration. That is, a data processing method for extracting the secondary information from a signal in which a minimum embedding section including a secondary information and a positioning signal for acquiring position information is repeatedly embedded is provided. A time movement calculating step of calculating a time direction movement added to the signal using the signal; and a time movement generating time movement correction data for correcting the time direction movement calculated in the time movement calculation step. A correction step, an effective area determination step of determining an effective area for determining the presence of the secondary information in the time movement correction data, and the secondary area from the effective area determined in the effective area determination step. And extracting an important information.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[Embodiment 1] In Embodiment 1 of the present invention, as shown in FIG. 18 described above, an image 902 in which a digital watermark is embedded is printed once, and then the printed image is read. A highly reliable method for extracting a digital watermark when the image is translated as a result will be described.

In the digital watermark embedding algorithm,
There is a case where additional information is repeatedly embedded in an image in order to extract additional information from a part of an image in which a digital watermark is embedded and to extract the additional information at high speed.

FIGS. 1A to 1C are diagrams for explaining the state.

FIG. 1A shows a minimum embedding unit 301 which is the smallest unit in which additional information can be embedded. FIG. 1B shows an original image 302, and FIG.
Is the minimum embedding unit 30 for the original image 302.
1 shows a state (303) in which embedding N is repeated in the form of a tile. When such an embedding algorithm is used, if at least one minimum embedding unit 301 is included in a part of the cut image, the additional information can be extracted.

FIG. 2 shows the configuration of a digital watermark extracting apparatus according to the present embodiment for extracting a digital watermark from an original image 302 in which the minimum embedding unit 301 is repeatedly embedded. According to this digital watermark extraction device, the calculation of the embedding position is simplified, and the extraction speed can be increased. FIG. 2 is a block diagram illustrating a process of extracting additional information from an image in which a digital watermark is repeatedly embedded in a minimum embedding unit according to the present embodiment.

In the figure, an image in which a digital watermark is embedded is first input to an averaging block acquisition unit 401.
The averaging block acquisition unit 401 collects a plurality of minimum embedding units 301 present in the input image into each block having the same size as that unit, and averages the pixel values at the corresponding positions of the blocks. Ask for a block. Then, the obtained averaged block is output to the additional information extraction unit 402 at the subsequent stage. The additional information extraction unit 402
According to the digital watermark embedding algorithm, additional information is extracted from the averaged block supplied from the averaged block acquisition unit 401.

Next, the operation of the averaging block acquisition unit 401 of FIG. 2 will be described in detail with reference to FIGS.

FIG. 3 is a flowchart showing a processing procedure in the averaging block acquisition section 401 according to the present embodiment, and FIG. 4 is a diagram schematically showing each processing in FIG.

In FIG. 3, first, in step S1, a block dividing process is performed on an image in which a digital watermark is embedded. In this block division processing, a block having the same size as the minimum embedding unit 301 is arranged in a tile shape on an image in which a digital watermark is embedded, and the image is divided.

In FIG. 4, reference numeral 601 indicates the concept of the operation performed in the block division processing. Next, the process proceeds to block integration processing in step S2,
As shown by, an integrated block is generated by taking the sum of the pixel values of the pixels in the corresponding positional relationship of all the blocks divided in step S1. Finally, in the block averaging process in step S3, each pixel value of the integrated block obtained in the block integration process in step S2 is divided by the number of pixels (the number of blocks) added for each pixel, and the average is calculated. Find the value.

As a result of the above processing, an averaging block having the same size as the minimum embedding unit 301 as shown by 603 in FIG. 4 is obtained. Above, the averaging block acquisition unit 4
01 has been described.

Next, the minimum embedding unit 30 as described above
In the digital watermark embedding algorithm for repeatedly embedding 1 in an image, a positioning signal for determining the amount of parallel movement added to the image will be described.

In general, as a method for calculating a parallel shift applied to an image in which a digital watermark is embedded, a method using a cross-correlation is well known. Cross-correlation is often used in the field of signal processing to check the similarity between two signal waveforms.

First, the cross-correlation will be briefly described with reference to FIGS.

In FIG. 5, reference numeral 101 denotes a one-dimensional wave,
Reference numeral 102 denotes another one-dimensional wave different from the waveform of the one-dimensional wave 101. In order to make the explanation easy to understand, it is assumed that the one-dimensional waves 101 and 102 are digital data having a period N which takes discrete values. Now, a cross-correlation function, which is one of the evaluation values for determining the similarity between the one-dimensional wave 101 and the one-dimensional wave 102, will be calculated.

In FIG. 5, the delay time t = 0 to t = N
In the section up to -1, the cross-correlation function C (t) is given by C (t) = (1 / N) × Σg (i) h (i + t), t =
0, 1,..., N−1 (where, Σ indicates the sum from t = 0 to t = N−1)
It is represented by

Basically, the cross-correlation function C (t) is accumulated by multiplying the signal waveform g (i) and the corresponding portion in the signal waveform h (i + t) shifted by the delay time t. ,
It is obtained by averaging it.

The cross-correlation function C (t) resulting from the cross-correlation between the one-dimensional wave 101 and the one-dimensional wave 102 is shown in a one-dimensional wave 104.

In the one-dimensional wave 104, the one-dimensional wave 102 is
The value of the correlation is highest when the parallel movement is performed to the position of the waveform indicated by the dotted line 103 (the amount of parallel movement is M in this case).

As described above, it is well known that the cross-correlation function is an effective part for determining the similarity between two waveforms.

In the above description, a one-dimensional wave has been described as an example, but the same principle can be used for a two-dimensional wave (image).

Next, the cross-correlation in an image will be described.

FIG. 6 is a diagram for explaining the correlation between signals having a two-dimensional spread.

In the figure, 201 indicates “1” or “−”.
1 "indicates a two-dimensional block randomly arranged at the same ratio. Note that 202 indicates the same two-dimensional block as 201. In general, a random signal has a large correlation when it overlaps itself. The correlation between the two-dimensional block 201 and the two-dimensional block 202 is maximized at the origin as indicated by 203. In this case, the two-dimensional block 2
If the translation has been applied to 02, the maximum of the correlation appears at a point away from the center by a distance corresponding to the translation amount.

By utilizing the above properties, a digital watermark embedded image may be generated by adding a random signal to the original image in advance as a signal for digital watermark alignment. At the time of alignment, the cross-correlation between the digital watermark embedded image and the random signal embedded for alignment is obtained, and the amount of parallel movement added to the image is determined from the coordinates of the maximum value of the correlation. Can be.

The M-sequence signal (Maximum Length Sequence)
nce) is a periodic signal composed of binary symbols, and the appearance probabilities of the binary symbols are almost equal, and they have sharp autocorrelation, so that they are suitable for detecting the amount of parallel movement. Also,
The alignment signal for detecting the amount of parallel movement may be a pattern that generally has a low correlation with the background image, and may not be a random signal.

In this embodiment, a case where a random signal is used as an example of a positioning signal will be described. However, a case where an M-sequence signal is used as a positioning signal is also included in the scope of the present invention.

As described above, by embedding not only additional information but also a signal for positioning in advance for each minimum embedding unit, the amount of parallel movement added to the image is detected, and the additional information is It becomes possible to extract.

The calculation of the correlation requires a large amount of calculation for a signal (image) having a large number of samples in the real space, and a large load is applied to the calculation processing. Therefore, high-speed positioning can be performed by performing frequency conversion on the signal to calculate a product, and then returning the signal to the real space to obtain the maximum value of the correlation. This utilizes the fundamental property of Fourier transform that convolution integral in real space is a product in frequency space of Fourier space.

As described above, when the positioning signal for calculating the amount of parallel movement is embedded together with the additional information in the minimum embedding unit, and the digital watermark is extracted from the image to which the parallel movement has been added, the digital watermark extracting apparatus is shown in FIG. It is preferable to take a configuration as shown in FIG.

FIG. 7 is a block diagram showing a functional configuration of the digital watermark extracting apparatus according to Embodiment 1 of the present invention.

First, an image in which a digital watermark is embedded is input to an averaging block acquisition unit 701. The averaging block acquisition unit 701 collects blocks of the size of the minimum embedding unit 301 in a tile form from the upper left of the image, and averages each pixel value of the blocks (see FIG. 4).
603) is calculated. And the averaging block acquisition unit 7
01 outputs the obtained averaged block to the subsequent-stage parallel movement amount calculation unit 702 and the additional information extraction unit 703.

The translation amount calculator 702 calculates the cross-correlation between the positioning signal and the averaging block. As described above, the translation amount added to the image can be determined based on the position where the value of the cross-correlation is the largest.
02 outputs the amount of parallel movement added to the image to the additional information extraction unit 703. At this time, in order to perform reliable positioning, when the maximum value of the cross-correlation between the positioning signal and the averaging block is equal to or less than a certain threshold, it may be determined that positioning cannot be performed.

The additional information extracting unit 703 extracts additional information from the position where the parallel movement amount input from the parallel movement amount calculating unit 702 has been corrected. Although there are various methods for embedding and extracting additional information, the description thereof will not be described in detail because it is different from the purpose of the present invention.

Next, the parallel movement amount output section 702 will be described in detail.

FIG. 8 shows the internal configuration of the parallel movement amount calculating section 702.
Shown in

First, the averaging block obtaining section 701 converts the averaging block and the positioning signal into a correlation calculating section 801.
Is input to The correlation calculator 801 calculates the cross-correlation between the two input signals, and outputs the calculation result of the cross-correlation to the peak position acquisition unit 802. The peak position acquisition unit 802 acquires a position at which the result of the cross-correlation calculation is maximum, and calculates the amount of translation added to the image.
However, here, the translation amount is the minimum embedding unit 30
Since the translation amount is calculated by 1, the remainder is obtained by dividing the actually added translation amount by the size of one side of the minimum embedding unit 301. But the minimum embedding unit is
Because it is repeatedly embedded, there is no obstacle to extraction.

As described above, the method of correcting the positional deviation due to the parallel movement and extracting the additional information in the digital watermark in which the minimum embedding unit is repeatedly embedded has been described.

Next, the image in which the digital watermark is embedded is
As shown in FIG. 18 described above, consider a case where a large margin is included in addition to the image area 0902 in which the digital watermark is embedded.

Here, a case where additional information is extracted from an image 901 including a large margin using the additional information extracting unit 703 in FIG. 7 will be considered.

First, an image 90 in which a digital watermark is embedded
1 is input to the averaging block acquisition unit 701, the averaging block is calculated, and the averaging block is output as the translation amount output unit 702.
And outputs the result to the additional information extraction unit 703. Next, the translation amount calculation unit 702 calculates the translation amount from the positioning signal and the averaging block, and outputs the calculated translation amount to the additional information extraction unit 703. Additional information extraction unit 7
In 03, the averaging block and the translation amount are input,
According to the additional information extraction algorithm, additional information is extracted from the position corrected by the amount of translation added to the image, and the additional information is output.

However, now, the averaging block acquisition unit 7
01 contains a large number of blank areas, and the digital watermark information reflected in the averaged blocks is affected by the averaging and weakens compared to the case where no blank areas are included. It is thought that there is.

As an example, some pixels of the minimum embedding unit 301 are randomly divided into two groups of A and B, and the pixel value of each group is changed from ai to ai + c in the case of group A. For the algorithm that embeds 1-bit information by changing the pixel value from bi to bi-c in the case of group B, and extracting additional information from the expected value 2c of the difference between the pixel values of group A and group B Think.

When such an algorithm is used, when an averaging block is created from an image containing a large amount of margin, the area of the margin is divided into groups A and B.
The expected value of the difference between the pixel values of “A” and “B” is “0” because no embedding is performed, and when the pixel values are averaged by the minimum number of embedding units, the expected value of the difference between the pixel values of Group A and Group B is It is smaller than when there is no margin. As a result, the reliability of the extracted information is reduced. In some cases, the expected value of the difference between the pixel values of the group A and the group B may fall below a threshold value set for reliable extraction, and additional information may not be extracted. Similarly, the positioning signal may be weakened by the influence of the averaging, and accurate positioning may not be performed.

In the present embodiment, first, a method of selecting a region considered to be an image using a histogram or an edge between an image and a margin, and calculating a parallel movement applied to the image is described. State.

As described above, when the geometric transformation added to the image is specified using only the selected image area, the influence of the area where the digital watermark is not embedded is reduced. Can be increased.

FIGS. 9A and 9B show an image area selection unit 1902 and a signal area selection unit 19 for extracting only the original image or signal area from the edited image or signal.
FIG. 5 is a diagram for explaining the input / output relationship of the input / output unit 05.

FIGS. 9A and 9B show an image area selecting section 190 for specifying an area in which a digital watermark is embedded.
2 schematically illustrates the process of FIG.

FIG. 9A shows an image area selection unit 1902.
However, FIG. 11 shows a state in which an image area 902 in which a digital watermark such as a photograph is embedded is specified from an input image 901 including a large amount of blank space, and only the image area 902 is output. This image area selection unit 1902 can be realized using a relatively simple principle. For example, as one method, there is a method of analyzing a histogram of pixel values of the input image 901 and selecting a sufficiently large rectangular area in which the number of pixels having a predetermined background pixel value is as small as possible.

As another method, as shown in FIG. 10, an edge position on a line of a vertical column (1603) and a horizontal row (1604) is detected with respect to an input image 901, and the vertical column and the horizontal line (1604) are detected. Each horizontal row may be moved from end to end to select a sufficiently large rectangular area surrounded by sharp edges.

Even when the input signal is a voice, as shown in the signal area selection unit 1905 of FIG. 9B, the area where the change of the signal value of the audio signal is "0" is reduced as much as possible. It can be realized by a method such as extracting a sufficiently large continuous signal region.

In the case of a moving image, various realization methods are conceivable. One method is to consider each frame as an image area, analyze its histogram and the like, and collect a sufficient number of frames satisfying the conditions. Such a method can be used in the same manner.

The above-described distinction between the image signal and the audio signal from the background that does not include the information signal can be realized by using an existing well-known technique.

Further, a simple but relatively practical image area selecting section 1902 (signal area selecting section 1905)
For example, there is a method of selecting a region of a fixed size from the center of an input image (input signal).

As described above, when specifying a geometric transformation added to a digital watermark from an image having a large margin, the above-described image area selecting section 1902 (signal area selecting section 1905)
Is used, it is possible to reduce the influence of the area in which the digital watermark is not embedded, and it is possible to improve the accuracy of the alignment with respect to the signal to which the digital watermark is added. The image region selection unit 1902 (signal region selection unit 1905) described above increases the accuracy of alignment by:
It can be attached as an option, and this image area selection unit 1902 (signal area selection unit 190
It is not necessary to adopt a configuration including 5).

Next, a method of narrowing down the area in which the digital watermark information is embedded using the positioning signal, extracting additional information from the narrowed-down area, and improving the reliability of the additional information is proposed.

FIG. 11 is a block diagram showing the internal configuration of the digital watermark extracting apparatus according to the first embodiment. Portions common to the above-described configuration are denoted by the same reference numerals, and description thereof will be omitted.

In the first embodiment, by arranging the effective area determination section 1302 at the preceding stage of the effective area averaging block acquisition section 1303, the area in which the digital watermark is embedded is determined, and a more reliable digital watermark is determined. Is being extracted.

Further, the above-described image area selecting section 1902 is arranged at the preceding stage of the parallel movement amount calculating section 702, and only the area where the digital watermark is likely to be embedded is used.
Specifies the translation added to the image.

Next, details of the digital watermark extracting apparatus shown in FIG. 11 will be described.

First, the image in which the digital watermark is embedded is input to the image area selection unit 1902. Image area selection unit 1
The image area 902 selects an image area by distinguishing the background area from the image area through the analysis of the histogram and edges of the input image as described above. Then, the image data of the image area and the position information of the selected image are converted into a parallel movement amount calculation unit
Send to The reason why the position information of the selected image is sent at the same time is that when calculating the amount of translation added to the input image, the amount of translation calculated from the selected image and the position information of the selected image are used. Because two are needed.

The translation amount calculator 702 analyzes the selected image area and calculates the translation amount. Since the selected image area is a part of the image, it is changed to the translation amount of the entire image in consideration of the position information of the originally input image, and is output to the subsequent translation correction unit 1301.

The parallel movement correction unit 1301 corrects the input image based on the amount of parallel movement added to the image in which the digital watermark is embedded, and the effective area determination unit 1301
Output to 2. The effective area determination unit 1302 determines the area of the input image in which the digital watermark is embedded using the alignment signal, and averages the effective area information, which is information on the area in which the digital watermark is embedded, in the effective area. Output to the block acquisition unit 1303. Note that the processing of the valid area determination unit 1302 will be described with reference to the flowchart in FIG.

Effective area averaging block acquisition section 1303
Acquires an averaging block of an area in which the digital watermark of the input image is embedded from the input effective area information, and outputs it to the additional information extraction unit 703. The additional information extracting unit 703 extracts additional information using an extraction algorithm corresponding to an additional information embedding algorithm.

Next, the internal processing of the effective area determination unit 1302 will be described in detail.

FIG. 12 is a flowchart showing a processing procedure of the effective area determination unit 1302.

First, in step S11, the image in which the digital watermark is embedded is first divided into blocks. In this block division processing, since an image in which a digital watermark with a corrected amount of parallel movement added to the image is embedded is input, the image is divided into a plurality of blocks so as to synchronize with the minimum unit 301 for embedding an electronic watermark.

The processing performed in this block division processing will be described with reference to FIGS.

Referring to FIG. 13A, reference numeral 901 denotes an example of an image in which a digital watermark input to the block division processing in step S11 is embedded. Then, in this block division processing, the input image 901 is
As shown in (B), it is divided into a plurality of blocks.

In FIG. 13B, since the division into blocks is performed by correcting the amount of parallel movement added to the digital watermark, the minimum unit for embedding the digital watermark and the divided block are synchronized. ing. In FIG. 13B, the area 12 as a result of the division by the block division processing is shown.
The entire image 02 is slightly larger than the image 901 in FIG. 13A because all regions of the input image are to be subjected to digital watermark extraction processing.

Returning to FIG. 12, in the positioning signal detection processing in step S12, a correlation value between each block divided in the block division processing in step S11 and the positioning signal of the positioning signal is calculated. However, since the translation amount has already been corrected here, the correlation is calculated only by calculating the average value of the sum of the product of the pixel value of the pixel of each block of the corresponding positional relationship and the coefficient of the alignment signal. Good (that is, the correlation value of the delay time t = 0) is calculated.

Cn = (1 / Nx) (1 / Ny) ΣΣBn
(I, j) × S (i, j) Here, the first を is the sum total from j = 0 to Nx, and the next Σ is i = 0
総 Ny. Also, Cn indicates a positioning correlation value between the Nth block and the positioning signal, and Bn (i,
j) is the pixel value of the coordinates (i, j) in the N-th block, S
(i, j) is a coefficient of the coordinates (i, j) in the alignment signal. Nx and Ny represent the numbers of vertical and horizontal pixels, respectively, in the minimum embedding unit (the same size as the block and the alignment signal).

In this way, in the positioning signal detection processing in step S12, the amount of calculation is smaller than the calculation of the cross-correlation function in the parallel movement amount calculation unit 702, so that the processing can be performed at higher speed.

Next, in step S13, in the threshold value determination processing, the correlation value of the positioning signal of each block calculated in the positioning signal detection processing in step S12 is compared with a threshold value, and the threshold value is determined. To determine whether the position information is embedded. The threshold value is calculated in consideration of the pattern of the positioning signal, the strength at the time of embedding the positioning signal, the variance of the image, and the like. If the correlation value of the positioning signal is equal to or larger than the threshold, step S1
The process proceeds to step S4, where the fact that the block is an effective area block in which a digital watermark is embedded is stored in the memory, and the process proceeds to step S15. On the other hand, if it is smaller than the threshold in step S13, the process proceeds to step S15. In step S15, it is determined whether or not the processing has been completed for all the blocks. If the processing has not been completed, the processing returns to step S12 to continue the processing of the unprocessed block. 1
The process in 302 ends.

The processing performed by the effective area determination unit 1302 will be further described with reference to FIG.

Referring to FIG. 12, reference numeral 1202 denotes a state in which the input image 901 in which the digital watermark is embedded is divided into blocks by the block dividing process in step S11. Further, the mark of “○” or “X” described in each block of 1202 indicates the correlation value of the positioning signal calculated in the positioning signal detection processing of step S12 in the threshold determination of step S13. This shows the result of determining whether or not the area is an effective area at or above the threshold. That is, blocks marked with “x” indicate blocks whose correlation value of the alignment signal is less than the threshold, and blocks marked with “ブ ロ ッ ク” indicate blocks whose correlation value of the alignment signal is greater than or equal to the threshold. The block is shown.

Effective area averaging block acquisition section 1303
Collects blocks determined to have a digital watermark embedded therein as indicated by the mark “図” in FIG. 13B, obtains an average block thereof, and outputs the averaged block to the additional information extraction unit 703 at the subsequent stage. I do.

The method of specifying the position where the digital watermark is embedded using the digital watermark alignment signal and detecting only the position where the digital watermark is embedded has been described in detail.

As described above, the image area selection unit 1902
By introducing the effective area determination unit 1302 into the digital watermark extracting device, it is possible to extract a digital watermark with higher reliability.

In the present embodiment, in order to give a sense of unity to the description, the effective area determination unit 1302 collects the blocks determined to have the digital watermark embedded therein and generates an averaged block. The case where the additional information is extracted from the averaging block has been described.

However, additional information can be extracted by the following method.

First, based on the digital watermark extraction algorithm, calculation processing for extraction is first performed from the valid area in which the digital watermark is determined to be embedded by the valid area determination unit 1302. Next, the result of the calculation process for extraction is put together for the entire effective area in which it is determined that the digital watermark is embedded, and the final additional information is extracted.

In this method, an image is averaged and then a calculation process for extraction is performed to extract additional information, or a calculation process for extraction is performed first, and the result is finally averaged to extract additional information. Or mathematically equivalent.

Therefore, a method of extracting additional information using an averaging block will be described in the following embodiments, but any of the extraction processes is included in the scope of the present invention.

[Second Embodiment] In the first embodiment, the effective area in which the digital watermark is embedded is determined by using the alignment signal for detecting the amount of parallel movement added to the digital watermark embedded image. Thus, a method for extracting a highly reliable digital watermark has been described.

On the other hand, in the second embodiment, a geometric transformation (affine transformation) including not only a parallel movement but also a primary transformation represented by scaling and rotation is performed in addition to the input digital watermark embedded image or signal. Think about what is being done.

Now, it is assumed that the digital watermark embedded image is an image to which a geometric transformation as shown by 1001 in FIG. 19 has been added. In the field of digital watermarking technology, a method of correcting an image embedded with a digital watermark to which a geometric transformation represented by rotation or scaling is added to an original geometric state is called registration.

FIG. 20 is a diagram showing the result of performing a registration process on 1001 in FIG.

By the registration processing for correcting the rotation, a new area 1104 is added to the image, and the ratio of the area 1103 in which the digital watermark is embedded to the entire image 1101 is further reduced. Also, a hatched area 110 generated by the registration processing for correcting the rotation.
4 and a margin 110 generated when the image is printed and read.
5, there is a possibility that a large difference in pixel value, that is, an edge may appear. It is actually possible that this edge has an adverse effect when extracting the additional information. The reason will be described using the additional information embedding algorithm described in the first embodiment as an example.

Normally, in order to prevent image quality deterioration of an image in which a digital watermark is embedded, a randomly determined group A,
The change amount c for the pixel values ai and bi of the pixels belonging to each of the groups B is set as small as possible.
Therefore, the expected value 2c of the difference between the pixel values of the group A and the group B is a relatively small value.

However, when the pixel value of the hatched area 1104 generated by the process of correcting the rotation is “0”, and the pixel value of the margin 1105 generated at the time of printing and scanning the image is “255”. A large difference of "255" occurs.

Therefore, when acquiring an averaging block from the entire image 1101 corrected for rotation and scaling,
An edge portion that does not include additional information is added to the block at the position where the digital watermark is embedded, and is averaged. At this time, the sign of the expected value 2c of the difference between the pixel values of the group A and the group B is reversed due to the large influence of the edge described above.
Eventually, a phenomenon may occur in which incorrect additional information is returned.

In the second embodiment, even when the geometric transformation such as translation, scaling, rotation, etc., applied to an image in which a digital watermark is embedded is corrected, the area in which the digital watermark is embedded is determined. We propose a method to enable reliable extraction of digital watermark.

Several algorithms have already been known as algorithms for correcting geometric transformation represented by rotation and scaling performed on an image in which a digital watermark is embedded. As a well-known method, when embedding a digital watermark, a signal having a plurality of strong peaks in an amplitude spectrum on a Fourier spatial frequency is used as a positioning signal.
Embed a dimensional wave. This signal is represented in space as a collection of two-dimensional waves having various frequencies.

When calculating the geometric transformation added to the image in which the digital watermark is embedded, first, a block having the same size as the above-described alignment signal is obtained from the image, and the power spectrum is calculated. Power spectra may be obtained from a plurality of blocks, and an average of the power spectra may be used. Next, the power spectrum of the alignment signal and
By examining the correspondence between a plurality of peaks of the power spectrum calculated from the image in which the digital watermark is embedded, it is possible to calculate the primary conversion amount including rotation and scaling applied to the image in which the digital watermark is embedded.

Regarding the amount of parallel movement added to the image in which the digital watermark is embedded, the search method using a signal (such as a random signal) for positioning described in the first embodiment or the above-described position A method of searching using a phase component on a Fourier spatial frequency of a combined signal is known.

It should be noted that an example of the above-described registration technique is disclosed in US Pat. No. 5,636,292, entitled “St.
eganography methods employing embedded calibration
data "and JP-A-11-35547," Geometric transformation specifying system "are also described in relatively detail.

Next, a digital watermark extracting apparatus according to the second embodiment will be described.

FIG. 14 is a block diagram showing the configuration of the digital watermark extracting apparatus according to the second embodiment. The digital watermark extracting apparatus shown in FIG. 11 is replaced with a translation correction unit 1301 and a geometric transformation correcting unit 1401. It has become.

The image in which the digital watermark is embedded is input to the image area selection unit 1902. This image area selection unit 1
In step 902, the background region and the image region are distinguished by analyzing the histogram and edges of the input image as described above, and the original image region is selected. Then, the image data of the image area and the position information of the selected image are sent to the subsequent geometric transformation calculation unit 1406. In this geometric transformation calculation unit 1406,
The selected image area is analyzed, and a primary conversion amount added to the image is calculated. Since the image area selected by the image area selection unit 1902 is a part of the image, it is changed to the geometric transformation amount for the entire image in consideration of the position information of the originally input image, and the geometric transformation correction unit 1401 in the subsequent stage is used. Output to The input image and the geometric transformation amount from the geometric transformation calculation unit 1406 are input to the geometric transformation correction unit 1401, and based on these, the geometric transformation added to the image in which the digital watermark is embedded is corrected. Valid area determination unit 140
Output to 2. The geometric transformation correction unit 1401 performs not only the primary transformation represented by rotation, scaling, and the like, but also
The translation amount can also be corrected.

In this way, an image in which a digital watermark corrected for geometric transformation is embedded is input to the effective area determination unit 1402. This effective area determination unit 140
2 uses an alignment signal to determine a region of the input image in which the digital watermark is embedded. Embodiment 2
In, the positioning signal used in the effective area determination unit 1402 is not limited to the random signal or the M-sequence signal for correcting the parallel movement described in the first embodiment,
An alignment signal capable of detecting conversion such as translation, scaling, rotation, etc. is used. Then, the valid area determination unit 1402 converts the image in which the digital watermark corrected for the geometric transformation is embedded and the valid area information into
It outputs to the effective area averaging block acquisition unit 1403. The effective area averaging block acquisition unit 1403 acquires an averaging block of an area in which the digital watermark of the input image is embedded from the input effective area information, and outputs the averaging block to the additional information extraction unit 703. The additional information extracting unit 703 extracts the additional information using an extraction algorithm corresponding to the additional information embedding algorithm.

As described above, the valid area determination unit 14
02 and the introduction of the image area selection unit 1902, the position where the digital watermark of the input image is embedded can be specified using the alignment signal, and the extraction of additional information with high reliability has become possible.

[Embodiment 3] In Embodiment 1 described above, an image is assumed as a signal in which a digital watermark is embedded. However, even in the case of audio data, a two-dimensional parallel movement is replaced by a time movement. This makes it possible to extract a reliable digital watermark on the same principle as in the first embodiment.

FIG. 15 shows the configuration of a digital watermark extracting apparatus for extracting additional information from music data to which time movement has been added.

The configuration of FIG. 15 is almost the same as that of the digital watermark extracting apparatus of FIG. 11 described in the first embodiment, and therefore the details are omitted, but are the same as those described in the first embodiment. In addition, even when the music data in which the digital watermark is embedded is edited, a reliable digital watermark can be extracted. Therefore, the case where music data is used instead of an image is also included in the category of the present invention.

[Fourth Embodiment] In the fourth embodiment, the extraction of a reliable digital watermark from moving image data will be considered.

As a digital watermark in a moving image, a method in which a digital watermark including a repetitive alignment signal is embedded in image data in each frame and a digital watermark signal is repeatedly embedded in a plurality of frames can be considered.

As editing performed on a moving image, a part of a moving image in which a digital watermark is embedded is added to another moving image, or the same geometric transformation is applied to the entire moving image. There are two ways. We assumed that the geometric transformations applied in each frame were the same because in a moving image composed of a series of similar images, different geometric transformations in each frame hindered the continuous movement of images between frames, This is because it is extremely unnatural and significantly impairs the quality of the work.

FIG. 16 is a block diagram showing the configuration of a digital watermark extracting apparatus for extracting additional information from digital watermark embedded moving image data to which image editing has been added, according to the fourth embodiment.

In FIG. 16, moving picture signal selecting section 1801
First, a histogram, a variance, and an edge are analyzed to clearly separate a moving image signal and a signal containing no information, a moving image signal is selected from the signals, and the selected signal is output to a subsequent geometric transformation correction unit. This operation is performed for each frame. A unit for distinguishing between a moving image signal and a signal containing no information (for example, an image having almost no change in the entire frame continues for a predetermined time or more) can be implemented relatively easily.

Next, the averaged image acquisition section 1802 collects frames determined as moving image signals, averages them, and
The averaged frame is output to geometric transformation correction section 1803. The geometric transformation correction unit 1803 specifies and corrects the geometric transformation added to the moving image signal from the averaged frame using the alignment signal. Then, the moving image signal whose geometric transformation has been corrected is converted into an effective area determination unit 1 at the subsequent stage.
804.

The effective area determination unit 1804 specifies the area in which the digital watermark is embedded in the moving image signal whose geometric transformation has been corrected, using the alignment signal. Then, the effective area averaging block acquisition unit 1805 acquires a block obtained by averaging the blocks in which the effective area determination unit 1804 has determined that the digital watermark is embedded, and outputs the block to the additional information extraction unit 1806. Thereby, the additional information extracting unit 1
806 extracts the additional information using an extraction algorithm corresponding to the additional information embedding algorithm.

Note that the geometric transformation correction section 1803, the effective area determination section 1804, and the effective area averaged block acquisition section 180
The processing performed in step 5 is almost the same as the processing in the geometric transformation correction unit 1401, the effective area determination unit 1402, and the effective area averaging block acquisition unit 1403 described in the second embodiment.

By using the digital watermark extracting device described above, even when the moving image data in which the digital watermark is embedded is edited, as in the case of the first and second embodiments described above, It is possible to extract a reliable digital watermark.

FIG. 17 is a block diagram showing a specific configuration example of the digital watermark extracting device according to the embodiment of the present invention.

In the figure, reference numeral 2011 denotes a CPU;
2 is a RAM, 2013 is a ROM, 2014 is a display control unit, 2015 is a display, 2016 is an operation input unit such as a keyboard and a mouse, and 2017 is a connection I / O of an operation input device such as a device keyboard and a mouse.
O, 2018 denotes an external storage device such as a hard disk device, and 2019 denotes a connection I / O of the external storage device 2018;
020 is a bus, 2021 is a color image scanner, 2
Reference numeral 022 denotes a connection I / O to an image input device such as a color image scanner. Reference numeral 2023 denotes an interface unit with a communication unit such as a network.

The digital watermark extracting apparatus described in the first to fourth embodiments of the present invention is stored in the ROM 2013 in advance as a computer-executable program, and after reading the program into the RAM 2012, or After the program stored in the external storage device 2018 is read into the RAM 2012 in advance, or the program is downloaded through the interface unit 2023 with a communication unit such as a network,
After reading into the program 2012, the program is executed by the CPU 2011.

An image from which a digital watermark is to be extracted can be input to a RAM 20 through a connection I / O 2022 using an input device such as a color image scanner 2021 or a digital camera in place of the color image scanner.
12 or stored in the external storage device 201
8. The data is stored in the RAM 2012 through the connection I / O 2019 or stored in the RAM 2012 through the communication interface 2012 such as a network.

If the target for extracting the digital watermark is an audio signal, the color image scanner 202 shown in FIG.
Connected I / O using an audio input device such as a microphone in place of
Is stored in the RAM 2012 through 2022,
Alternatively, the RAM 201 is stored in the RAM 2012 through the external storage device 2018 and the connection I / O 2019 or the RAM 201 through the communication unit 2023 such as a network.
2 is stored.

In the case where moving image data is to be extracted from the digital watermark, the color image scanner 2 shown in FIG.
021 using an input device such as a digital camera,
It is stored in the RAM 2012 through the connection I / O 2022, or stored in the external storage device 2018, the connection I / O 20.
19, or is stored in the RAM 2012 through a communication interface 2023 such as a network.

The digital watermark extracting program is as follows:
Control is performed through an input from a keyboard & mouse 2016 or a communication unit 2023 such as a network.

Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), a device including one device (for example, a copying machine, a facsimile machine, etc.) ) May be applied.

An object of the present invention is to provide a storage medium (or a storage medium) in which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or an apparatus, and to provide a computer (or This is also achieved by a CPU or an MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. When the computer executes the readout program codes, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instructions of the program codes. This also includes a case where some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instruction of the program code. This also includes the case where the CPU provided in the function expansion card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

As described above, according to the present embodiment, an image in which a digital watermark is embedded is corrected for the added geometric transformation, then divided into blocks, and the image is correlated with the alignment signal. By specifying an effective area, a reliable digital watermark can be extracted from the effective area.

[0144]

As described above, according to the present invention, after correcting a geometric transformation added to an image or a signal in which secondary information such as a digital watermark is embedded, the secondary information is corrected. Has the effect that highly reliable information can be extracted.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating how a minimum embedding unit is repeatedly embedded in an original image.

FIG. 2 is a block diagram illustrating a process of extracting additional information from an image in which a digital watermark is repeatedly embedded in minimum embedding units according to the present embodiment.

FIG. 3 is a flowchart showing a processing procedure in an averaging block acquisition unit according to the present embodiment.

FIG. 4 is a diagram schematically illustrating a process of an averaging block acquisition unit.

FIG. 5 is a diagram illustrating a cross-correlation between two one-dimensional waves.

FIG. 6 is a diagram illustrating the correlation of signals having a two-dimensional spread.

FIG. 7 is a block diagram illustrating an internal configuration of a digital watermark extraction device that extracts additional information from an image to which translation has been added.

FIG. 8 is a block diagram illustrating an internal configuration of a parallel movement amount calculating unit according to the present embodiment.

FIG. 9 is a diagram illustrating an input / output relationship between an image area selection unit and a signal area selection unit that extracts only an original image or a signal area from an edited signal.

FIG. 10 is a diagram for explaining one method for realizing an image area selecting unit.

FIG. 11 is a block diagram showing an internal configuration of the digital watermark extraction device according to the first embodiment of the present invention.

FIG. 12 is a flowchart showing a process in an effective area determination unit according to the present embodiment.

FIG. 13 is a diagram illustrating how to determine an effective area in which a digital watermark is embedded.

FIG. 14 is a block diagram showing an internal configuration of a digital watermark extraction device that extracts a digital watermark according to Embodiment 2 of the present invention.

FIG. 15 is a block diagram showing an internal configuration of a digital watermark extraction device according to Embodiment 3 of the present invention.

FIG. 16 is a fourth embodiment for extracting additional information from digital watermark embedded moving image data to which image editing has been added;
1 is a block diagram illustrating a configuration of a digital watermark extraction device according to the first embodiment.

FIG. 17 is a block diagram showing a configuration of a computer device for executing a digital watermark extraction processing program according to the present embodiment.

FIG. 18 is a diagram illustrating an example of a state where a blank area is added to an area in which a digital watermark is embedded.

FIG. 19 is a diagram illustrating an example of a digital watermark embedded image to which a geometric transformation including scaling, rotation, and translation has been added.

20 is a diagram illustrating an example of an image obtained by correcting the geometric transformation added to the image in which the digital watermark in FIG. 19 is embedded.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5B057 CB19 CE08 DA07 DA20 DC02 DC08 5C063 AB03 AB05 CA23 CA34 CA36 DA13 DA20 5C076 AA14 AA23 AA24 BA06 CA10 5J104 AA14 AA15

Claims (34)

[Claims] 1. An image processing apparatus for extracting secondary information from an image in which a minimum embedding unit including a positioning signal for acquiring secondary information and position information is repeatedly embedded. A geometric transformation calculating unit that calculates a geometric transformation amount added to the image using the alignment signal; and a geometric transformation corrected image that has been corrected for the geometric transformation amount calculated by the geometric transformation calculating unit. Generating a geometric transformation correction unit, an effective region determination unit for determining an effective region for determining the presence of the secondary information in the geometric transformation correction image, and the effective region determined by the effective region determination unit. An image processing apparatus comprising: an extraction unit configured to extract the secondary information. 2. The method according to claim 1, wherein the effective area determining unit includes: an area dividing unit that divides the geometric transformation corrected image into a plurality of blocks; and an alignment signal related to the position information for each of the plurality of blocks. Positioning signal detection means for calculating a positioning signal correlation value representing the correlation, and comparing the positioning signal correlation value for each of the plurality of blocks with a threshold to determine the effective area. The image processing apparatus according to claim 1. 3. The image processing apparatus according to claim 1, wherein an area used by the geometric transformation calculation unit to calculate the geometric transformation amount is a part of an input image. 4. The image processing apparatus according to claim 3, wherein the area is determined based on characteristics of the input image. 5. The image processing apparatus according to claim 1, wherein the geometric transformation amount includes a primary transformation amount and a translation amount. 6. The image processing apparatus according to claim 2, wherein each of the plurality of blocks has the same size as the minimum embedding unit. 7. The image processing apparatus according to claim 1, wherein the positioning signal is a random signal. 8. The image processing apparatus according to claim 1, wherein the positioning signal is an M-sequence signal. 9. The image processing apparatus according to claim 1, wherein the alignment signal is a signal that can detect a primary conversion amount applied to the image, including at least rotation or scaling, by frequency analysis of the image. 2. The image processing device according to 1. 10. An image processing method for extracting secondary information from an image in which a minimum embedding unit including a positioning signal for obtaining secondary information and position information is repeatedly embedded. A geometric transformation calculating step of calculating a geometric transformation amount added to the image using the alignment signal; and generating a geometric transformation corrected image obtained by performing a correction on the geometric transformation amount calculated in the geometric transformation calculating step. A geometric conversion correction step, an effective area determination step of determining an effective area for determining the presence of the secondary information in the geometric conversion correction image, and the effective area determined in the effective area determination step. An image processing method, comprising: an extraction step of extracting secondary information. 11. The effective area determination step includes: an area division step of dividing the geometric transformation correction image into a plurality of blocks; and an alignment signal related to the position information for each of the plurality of blocks. An alignment signal detection step of calculating an alignment signal correlation value representing the correlation, and comparing the alignment signal correlation value for each of the plurality of blocks with a threshold to determine the effective area. The image processing method according to claim 10, wherein 12. A data processing apparatus for extracting secondary information from a signal in which a minimum embedding section including a positioning signal for acquiring secondary information and position information is repeatedly embedded, Time movement calculating means for calculating a time-direction movement added to the signal using the positioning signal; and time-movement correction data obtained by correcting the time-direction movement calculated by the time movement calculation means. Time movement correction means to generate, in the time movement correction data, an effective area determination means for determining an effective area for determining the presence of the secondary information, and from the effective area determined by the effective area determination means A data processing device comprising: an extraction unit configured to extract the secondary information. 13. The method according to claim 13, wherein the effective area determination unit is configured to: divide the time movement correction data into a plurality of sections; and for each of the plurality of sections, a positioning signal related to the position information for each section. Positioning signal detection means for calculating a positioning signal correlation value representing the correlation, and determining the effective area by comparing the positioning signal correlation value for each of the plurality of sections with a threshold value. The data processing device according to claim 12, wherein: 14. An area used by said time movement calculating means for calculating a time movement added to said signal is a part of an input signal.
4. The data processing device according to 3. 15. The data processing apparatus according to claim 12, wherein the area is determined based on characteristics of the signal. 16. The data processing apparatus according to claim 12, wherein the signal includes audio data. 17. The data processing apparatus according to claim 12, wherein the section has the same length as the minimum embedding section. 18. The data processing device according to claim 12, wherein the positioning signal is a random signal. 19. The data processing device according to claim 12, wherein the positioning signal is an M-sequence signal. 20. A data processing method for extracting secondary information from a signal in which a minimum embedding section including a positioning signal for acquiring secondary information and position information is repeatedly embedded, the secondary information comprising: A time movement calculating step of calculating a time direction movement added to the signal using the positioning signal; and generating time movement correction data for correcting the time direction movement calculated in the time movement calculating step. A time-movement correction step to perform, in the time-movement correction data, an effective area determination step of determining an effective area for determining the presence of the subsidiary information, and the effective area determined in the effective area determination step. An extraction step of extracting side information. 21. An effective area determining step, comprising: a section dividing step of dividing the time movement correction data into a plurality of sections; and for each of the plurality of sections, a positioning signal relating to the position information for each section. A positioning signal detection step of calculating a positioning signal correlation value representing the correlation, and determining the effective area by comparing the positioning signal correlation value for each of the plurality of sections with a threshold value. The data processing method according to claim 20, wherein 22. An image for extracting the secondary information from moving image data repeatedly embedded in each frame, wherein a minimum embedding unit including a positioning signal for acquiring secondary information and position information is provided. A processing device, a selection unit that selects a partial region including a plurality of frames from the moving image data, an averaged image acquisition unit that generates an averaged image in frame units from the partial region, A geometric transformation calculating unit configured to calculate a geometric transformation added to the averaged image using a positioning signal; and generating a geometric transformation corrected image in which the geometric transformation calculated by the geometric transformation calculating unit is corrected. Geometric transformation correcting means, area dividing means for dividing the geometric transformation corrected image into a plurality of blocks, and the position information for each of the plurality of blocks for each block Positioning signal detection means for calculating a positioning signal correlation value representing the correlation with the positioning signal, and comparing the positioning signal correlation value for each of the plurality of blocks with a threshold value; An image processing apparatus comprising: an effective area determining unit that determines an effective area to determine presence; and an extracting unit that extracts the secondary information from the effective area determined by the effective area determining unit. apparatus. 23. A part of the plurality of frames is determined based on characteristics of an input moving image.
An image processing apparatus according to claim 1. 24. The image processing apparatus according to claim 22, wherein the geometric transformation includes a primary transformation or a translation. 25. The apparatus according to claim 22, wherein the block has the same size as the minimum embedding unit. 26. The image processing apparatus according to claim 22, wherein the positioning signal is a random signal. 27. The image processing apparatus according to claim 22, wherein the positioning signal is an M-sequence signal. 28. The image processing apparatus according to claim 28, wherein the alignment signal is a signal capable of detecting, by frequency analysis, an image in which a digital watermark is embedded in a primary conversion amount including rotation and scaling applied to the image. The image processing device according to claim 22. 29. The image processing apparatus according to claim 22, wherein the block has the same size as the minimum embedding unit. 30. An image for extracting the secondary information from moving image data repeatedly embedded in each frame, the minimum embedding unit including a positioning signal for obtaining secondary information and position information. A processing method, wherein: a selecting step of selecting a partial area including a plurality of frames from the moving image data; an averaged image obtaining step of generating an averaged image in frame units from the partial area; A geometric transformation calculating step of calculating a geometric transformation added to the averaged image by using a positioning signal; and a geometric transformation generating a geometric transformation corrected image obtained by correcting the geometric transformation calculated in the geometric transformation calculating step. A transformation correction step, an area division step of dividing the geometric transformation correction image into a plurality of blocks, and the position information for each block for each of the plurality of blocks. A positioning signal detection step of calculating a positioning signal correlation value representing a correlation with the positioning signal, and comparing the positioning signal correlation value for each of the plurality of blocks with a threshold value; Image processing comprising: an effective area determination step of determining an effective area for determining presence; and an extraction step of extracting the secondary information from the effective area determined in the effective area determination step. Method. 31. A storage medium storing a program for executing the image processing method according to claim 10. Description: 32. A storage medium storing a program for executing the data processing method according to claim 20. 33. A program for executing the image processing method according to claim 10. Description: 34. A program for executing the data processing method according to claim 20.