JP2001326805A - Image processing unit and method, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system by which attached information can be imbedded as much as possible to a received color image and devices through which image data pass can be recognized as to the image data passing through a plurality of the devices. SOLUTION: In the case that an image input section 1 receives image data 101 having color components and a quantization processing section 23 quantizes at least one color component of the data, a device ID used for history information and a newest flag denoting the history information to be newest information are imbedded as electronic watermark information.

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 method, and a recording medium, and more particularly, to an image processing apparatus having a function of embedding additional information relating to image processing or the like in image data and a method therefor.

[0002]

2. Description of the Related Art The image quality of digital color image forming apparatuses such as printers and copiers has been greatly improved, and high-quality full-color printed materials can be easily obtained. That is, anyone can obtain a desired printed matter by performing image processing using a high-performance scanner, printer, copier, and computer. On the other hand, there is a problem that banknotes and securities are forged, and there is an image processing apparatus equipped with a function for preventing forgery.

The forgery prevention function generally comprises two functions, a forgery tracking function and a forgery recognition function. The forgery tracking function embeds, for example, a regular dot pattern representing an ID or a model code unique to the printing apparatus in an image to be printed.
When a counterfeit banknote is found, the ID and the model code are extracted from the dot pattern embedded in the image of the counterfeit banknote, and the printing apparatus used for counterfeiting is specified.

[0004] It is known that the above dot pattern is embedded in a print image formed of, for example, yellow, magenta, cyan and black color components using yellow having the lowest visibility.

[0005]

Considering the recent development of computer networks, including the Internet, and the fact that image data is communicated over them,
It is necessary to embed as much information as possible, such as the ID and model code, in the image. In particular, it is more preferable that the history information indicating the device through which the image data distributed on the network has passed, that is, the device through which the image data has passed, can be efficiently embedded.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a function of embedding as much additional information as possible in an input color image.

It is another object of the present invention to be able to recognize a device that has passed through image data that has passed through a plurality of devices.

[0008]

The present invention has the following configuration as one means for achieving the above object.

[0009] An image processing apparatus according to the present invention is characterized in that: input means for inputting image data having a plurality of color components; and at least one of the plurality of color components has the first information and the first information updated. And embedding means for embedding second information indicating the information as digital watermark information.

An input unit for inputting image data having a plurality of color components; a processing unit for dithering the plurality of color components; and a plurality of dither patterns selectively applied to the dither processing by the processing unit By letting
Embedding means for embedding the first information in the first color component and the second information in the second color component as digital watermark information among the plurality of color components, respectively.

According to the image processing method of the present invention, image data having a plurality of color components is input, and at least one of the plurality of color components has the first information and the first information in the latest information. It is characterized by embedding second information indicating existence as digital watermark information.

Also, by inputting image data having a plurality of color components and selectively dithering the plurality of color components, a plurality of dither patterns are selectively applied.
The first information is embedded in the first color component of the plurality of color components, and the second information is embedded in the second color component as digital watermark information.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image processing apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

[Image Data Processing Path] FIG. 1 is a diagram showing an example of an image data processing path in the present embodiment. The device described in the present embodiment will be described as a device having a print function (a so-called printer). However, the present invention is not limited to this. For example, the present invention can be applied to a device that can input, process, and output image data.

First, an image input unit 1 such as a scanner, a general-purpose interface, a network interface, etc.
Image data 101 composed of RGB components of bits is input to the printer driver 2. In the printer driver 2, the image data 101 is converted into 8-bit RGB data 102 for each color according to the characteristics of the printer engine 3 by a correction process 21 that performs a masking process, a gamma correction, and the like. RGB data 10
2 is converted into 8-bit CMYK image data 103 of each color by a color conversion process 22 that performs logarithmic conversion, masking process, under-color removal process, and the like. Further, the CMYK image data 103 is binarized by the quantization process 23 for performing the pseudo gradation process,
CMYK binary image data 104 of 1 bit for each color is generated.

The CMYK binary image data 104 is sent to the printer engine 3 and an image is recorded on a recording medium such as paper. By supplying the created printed matter to the image input unit 1 such as a scanner, it is possible to obtain color image data composed of RGB components again.

[Embedding of History Information] In this embodiment, the CM
Digital watermark information is embedded in each color component of YK. Specifically, when the CMYK image data 103 is binarized, digital watermark information is embedded by switching a plurality of dither patterns. Before embedding, CMYK image data 103
It is determined whether or not the digital watermark information is embedded in the above-described method. If the digital watermark information is already embedded, the color component in which the latest electronic watermark information is embedded is determined.

In the present embodiment, the above-mentioned history information is embedded using digital watermark information. That is, a maximum of four pieces of history information indicating the image or the device through which the image data has passed can be embedded in each of the CMYK colors. Note that the order of colors in which the history information is embedded is, for example, C, M, Y, and K, and the latest history information is embedded recursively.

The embedding and extraction of the electronic watermark information and the analysis and creation of the history information are performed by the CPU 4 executing the program stored in the ROM 41 using the RAM 42 shown in FIG. 1 as a work memory.

FIG. 2 is a view showing the concept of the embedding order of the history information.

First, consider the image output (printed) for the third time through the processing path as shown in FIG. In the third output image, as shown in FIG. 2, C, M
The “device ID” and the “latest flag” that are history information are embedded in the color components Y and Y. The device ID is an ID indicating the device that has output the image. The latest flag is a flag indicating that the information is the latest in the history information embedded in the image, and “1” indicates that the information is the latest, and “0” indicates that the information is not the latest.

Accordingly, when digital watermark information is extracted from the third output image, the device ID is obtained from the C, M, and Y color components, indicating that there are three devices through which the image or image data has passed. From the K color component, information indicating that the device ID is empty (indicated by “*” in FIG. 2) is obtained. Also, '1' is the latest flag from the Y color component,
'0' is obtained from other color components.

Next, a case where image data is read from a third output image and a fourth image output (print) is performed will be described.

The RGB image data input from the image input unit 1 (such as a scanner) is converted into CMYK image data,
Digital watermark information embedded in the image data is extracted. Here, the device ID is extracted from the C, M, and Y color components, and the latest flag extracted from the color components indicates that the history information extracted from the Y color component is the latest.

Thereafter, the history information is embedded by a method described later. At this time, the same history information as the extracted history information is embedded again in the C and M color components. On the other hand, history information in which the latest flag is changed from “1” to “0” is embedded in the Y color component. Then, for the K color component, the latest flag is changed from '0' to '1', and the device ID indicating the sky
Is changed to the device ID (“4” in FIG. 2) indicating the device that performed the fourth process.

Next, the case where image data is read from the fourth output image and the fifth image output (print) is performed will be described.

The RGB image data input from the image input unit 1 (scanner or the like) is converted into CMYK image data,
Digital watermark information embedded in the image data is extracted. Here, the device ID is extracted from the C, M, Y, and K color components, and the latest flag extracted from the color components indicates that the history information extracted from the K color component is the latest.

Thereafter, the history information is embedded by a method described later. At this time, the same history information as the extracted history information is embedded again in the M and Y color components. On the other hand, history information in which the latest flag has been changed from “1” to “0” is embedded in the K color component. For the C color component, the latest flag is changed from “0” to “1”, and the device ID (“1” in FIG. 2) indicating the device that performed the first process is changed to the fifth time. The changed history information is embedded in the device ID ("5" in FIG. 2) indicating the device that performed the process.

As described above, the updating of the device ID and the latest flag of the history information in the present embodiment is realized by repeatedly embedding the latest history information in each color component. Also,
In the present embodiment, it is possible to embed up to four pieces of the latest history information in an image by sequentially and recursively embedding the latest device ID into the C, M, Y, and K color components. . In other words, it is possible to embed in the image the history information indicating the four devices through which the image or the image data has passed and their order.

[History Information Embedding Method] Next, an example of a method of embedding history information as digital watermark information will be described.

In this embodiment, embedding of digital watermark information is performed when binarizing multi-valued CMYK image data for each color. This concept is briefly described.

FIG. 10 is a diagram showing an example of a bit string constituting the history information. Assuming that 1401 is a 7-bit device ID and 1402 is a 1-bit latest flag, the history information is composed of 8 bits. In order to embed this 8-bit information when binarizing a certain color component, an area for at least eight dither patterns is secured from the color component data. By selectively using the dither pattern indicating the bit '1' and the dither pattern indicating the bit '0' in these eight areas, and performing binarization, one history is obtained in the eight areas. Information can be embedded.

It is preferable that the difference between the two types of dither patterns is visually invisible and the difference is apparent in data. In the present embodiment, history information is embedded as digital watermark information using at least first and second dither patterns described later.

[Dither Pattern] FIGS. 3 to 7 are photographs showing five examples of dither patterns used for embedding digital watermark information.

The photograph shown on the left side of FIG. 3 shows the distribution of threshold values of an M × M dither pattern (first dither pattern). The threshold value is from 0 to 255. The black portion indicates the threshold value 0, and the white portion indicates that the threshold value is closer to the threshold value 255. Note that the thresholds in the dither pattern are distributed to make it difficult for the human eye to recognize them.

The photograph shown on the right side of FIG. 3 shows a spectral distribution of amplitude obtained by performing a discrete Fourier transform (DFT) on the first dither pattern. The dimension number of this spectrum distribution is also M × M. Here the center represents the direct current (DC) component,
The peripheral portion represents a high frequency (AC) component, and the farther away from the center, the higher the frequency component. The black dots indicate that the spectrum is weak, and that the whiter the spectrum is, the stronger the spectrum is.

As can be seen from these photographs, it is known that the frequency components of the dither pattern are biased toward high frequency components.

A feature of the first dither pattern used in this embodiment is that the bias of the high frequency component is not uniform with respect to the DC component (center). That is, as shown in the photograph on the right side of FIG. 3, there are very few high-frequency components located vertically from the center.

The photograph on the left side of FIG. 4 shows the distribution of threshold values of an M × M-dimensional dither pattern (second dither pattern). The photograph shown on the right side of FIG. 4 shows the spectral distribution of the amplitude obtained by DFT of the second dither pattern.

The feature of the second dither pattern used in this embodiment is that the bias of the high frequency component is not uniform with respect to the DC component (center). That is, as shown in the photograph on the right side of FIG. 4, there are very few high frequency components located horizontally from the center.

If two of the dither patterns shown in FIGS. 3 and 4 are selectively used, bits can be embedded in an image. However, if the same dither pattern is used for a plurality of color components, there is a problem that the image quality deteriorates easily. Therefore, in order to avoid this, dither patterns shown in FIGS. 5 to 7 are prepared. It is also possible.

The photograph on the left side of FIG. 5 shows the distribution of threshold values of an M × M-dimensional dither pattern (third dither pattern). The photograph on the right side of FIG. 5 shows the spectral distribution of the amplitude obtained by DFT of the third dither pattern.

The feature of the third dither pattern is that the bias of the high frequency component is not uniform with respect to the DC component (center). That is, as shown in the photograph on the right side of FIG. 5,
Very few high-frequency components are located in the vertical direction from the center.

The first dither pattern and the third dither pattern have similar frequency characteristics, but differ in the method of arranging the thresholds. This takes into account the application of the first dither pattern to the binarization of the first color component and the application of the third dither pattern to the binarization of the second color component. In other words, even though the spectral distributions are similar,
By using dither patterns having different arrangements of thresholds for binarizing different color components, they are designed so that the printing positions of the respective color components are unlikely to overlap.

The photograph on the left side of FIG. 6 shows the distribution of threshold values of an M × M dither pattern (fourth dither pattern). The photograph on the right side of FIG. 6 shows the spectral distribution of the amplitude obtained by DFT of the fourth dither pattern.

The feature of the fourth dither pattern is that the bias of the high frequency component is not uniform with respect to the DC component (center). That is, as shown in the photograph on the right side of FIG. 6,
Very few high frequency components located horizontally from the center.

Although the second dither pattern and the fourth dither pattern have similar frequency characteristics, similar to the relationship between the first dither pattern and the third dither pattern, the arrangement method of the threshold values is the same. Are different.

The first and second dither patterns are used, for example, for embedding digital watermark information in C and Y color components, and the third and fourth dither patterns are used, for example, for digital watermark information in M and K color components. Can be used for embedding. Further, the fifth and sixth dither patterns having the relationship of the first and second dither patterns, the seventh and eighth dither patterns are prepared, and the first and second dither patterns are provided for the C color component. The third and fourth dither patterns are applied to the Y color component, the fifth and sixth dither patterns are applied to the M color component, and the seventh and eighth dither patterns are applied to the K color component. Information may be embedded.

The photograph on the left side of FIG. 7 shows the distribution of threshold values of the fifth dither pattern of M × M dimension. In the present embodiment, the fifth dither pattern plays a role of a basic dither pattern that is usually used, and is used for binarization when there is a color or area in which digital watermark information is not embedded.

The photograph on the right side of FIG. 7 is a diagram showing the spectral distribution of the amplitude obtained by DFT of the fifth dither pattern. In the spectral distribution of the fifth dither pattern, the bias of the high-frequency component is uniform with respect to the DC component (center).

Each of the spectral distributions shown in the photographs of FIGS. 3 to 6 has a larger absolute value of the covariance than the spectral distribution shown in the photograph of FIG. In addition, in the spectral distribution obtained by converting the threshold values of the first and second dither patterns into frequency components, as shown in the right photographs of FIGS. 3 and 4, the bias of the high frequency components occurs in directions orthogonal to each other. . The same applies to the third and fourth dither patterns.

Next, the difference between the first dither pattern and the third dither pattern or the difference between the second dither pattern and the fourth dither pattern will be briefly described.

FIG. 8 is a diagram showing a threshold arrangement of the first or second dither pattern when M = 5. In addition, from 1 to 2
The number 5 is an index indicating the sequence, not the threshold itself. FIG. 9 is a diagram showing a threshold arrangement of the third or fourth dither pattern when M = 5. Compared to FIG. 8, each column is shifted to the right by one pixel. Therefore, when considered on a pixel-by-pixel basis, the binarization result using the first or third dither pattern or the second or fourth dither pattern is different even if the original multi-valued component is the same. become.

[History Information Embedding Processing] FIG. 11 is a flowchart showing an example of processing for embedding history information in an image. Here, a case where history information is embedded in the fourth output image shown in FIG. 2 will be described.

First, in order to embed history information in the C color component, image data of the C color component (C component data) is read.
(S1501), as shown in FIG. 12, the C component data is divided into blocks of M × M pixels. Note that each cell in FIG. 12 is a block of M × M pixels, and an index i indicating a row number is provided in the vertical direction.
An index j indicating a column number is given in the horizontal direction.

[0056] In FIG. 12, the index number becomes n × n matrix, n ^{2-dimensional} index vector is generated from the index matrix (S1502). At this time, the element number of the index vector becomes the index number of each block.

Next, predetermined seed information or user
1 to n based on the species information entered by ^TwoA random number is generated
(S1503). The generated random number is the generated index
Corresponds to the element number of the vector. In other words, random numbers are
Index number. An example is shown in FIG.
History information bit string and block index number
Is associated (S1504). At this time, until the end of the bit sequence
When the mapping is completed, the mapping starts again from the beginning of the bit sequence.
Perform

FIG. 13 is a diagram showing an example of correspondence between a bit string, a random number string, and a block index number. And the total number of bits of the repeated 1701 bit sequence, the number of elements of the random number sequence 1702 which indicates the index number of blocks are both ² n.

Next, an index number and a bit corresponding to the first element x = 1 of the random number sequence are obtained (S1505). Then, M × M pixel data corresponding to the obtained index number is obtained (S1506), and the obtained bit is determined (S1507).
And if the bit is '0', it is the first dither pattern,
If the bit is “1”, the M × M pixel data is binarized with the second dither pattern (S1508 or S1509).

Then, according to the determination in step S1510, steps S1505 through S1505 are repeated until all elements of the random number sequence are exhausted.
Repeat the process of 1509.

Next, in order to embed history information in each of the M and Y color components, the processing shown in FIG. 11 is performed on each of the M and Y component data. Then, in order to embed the history information of the device ID “4” and the latest flag “1” in the K color component, the process shown in FIG. 11 is performed on the K component data. When embedding the history information in the M, Y, and K component data as necessary, the third, fifth, and seventh dither patterns are used as the dither patterns used in step S1507, and the dither patterns used in step S1508 are used. Fourth, sixth, and seventh dither patterns are employed as patterns.

As described above, the CMYK binary image data in which the history information is embedded as the digital watermark information is sent to the printer engine 3 as the image data 104 shown in FIG.
An image is printed on a recording medium such as paper.

[History Information Extraction Processing] FIG. 14 is a flowchart showing an example of processing for extracting history information embedded as digital watermark information in an output image.

First, an image of a printed matter is read by a scanner to obtain 8-bit RGB image data (S1901). Then, the RGB image data is converted into CMYK image data (S190
2).

Next, after converting (correcting) the image data to the image size when the history information is embedded (S1903), FIG.
As shown in 2, the color component data is divided into blocks of M × M pixels, to generate the n ^{2-dimensional} index vector (S19
04).

The conversion (correction) of the image size is performed based on a registration signal embedded in the frequency domain of the image before and after embedding the digital watermark. In other words, the image is converted into a signal in the frequency domain to detect the registration signal, and the geometric relationship between the embedding position (in the frequency domain) of the registration signal and the detection position (in the frequency domain) is determined. You can know whether a geometric transformation (enlargement, reduction, rotation, etc.) has been performed. Therefore, by detecting the registration signal, it is possible to convert (correct) the image before the geometric conversion is performed.

As for the block size, the program for embedding a digital watermark or the like and the program for extracting a digital watermark or the like have the same block size. However, it is necessary to separately know the resolution of the image in which the digital watermark output to the printer is embedded.

Next, predetermined seed information or user
1 to n based on the species information entered by ^Two(S1
905), the index corresponding to the first element x = 1 of the random number sequence
Index number (S1906), and
M × M pixel data of the corresponding block is obtained (S1907).

The M × M image data is subjected to DFT to obtain an amplitude spectrum distribution (S1908), and a distribution equal to or smaller than the threshold value S0 is generated from the obtained amplitude spectrum distribution (S190).
9). The first principal component vector is obtained based on the two-variable distribution equal to or smaller than the threshold value S0 (S1910). The first principal component vector in the distribution as shown in the photographs on the right side of FIGS. 3 and 4 corresponds to the vector in the direction in which the distribution below the threshold value S0 is present from the center.

Note that the amplitude spectral distribution of the first and second dither patterns, the two-variable distribution equal to or smaller than the threshold value S0, and the first principal component vector may be generated in steps S1908 to S1910. It can be generated and stored in the ROM 41 or the like. In the following, the first principal component vector of the first dither pattern is referred to as “first vector”, the first principal component vector of the second dither pattern is referred to as “second vector”, and M × M pixel data Is referred to as a “vector of the observed image”.

The similarity M1 is calculated from the inner product of the vector of the observation image thus obtained and the first vector (S1911),
The similarity M2 is calculated from the inner product of the vector of the observation image and the second vector (S1912). Then, comparing the similarities M1 and M2 (S1913), if M1> M2, it is determined that the embedded bit is' 0 '(S1914), and if M1 ≦ M2, the embedded bit is' It is determined to be 1 '(S1915).

Then, according to the determination in step S1916, steps S1906 to S1906 are repeated until all elements of the random number sequence are exhausted.
Step 1915 is repeated.

A majority decision is made from the bit string extracted in this way, and the embedded bit string is reproduced.

By performing the above processing for each color component data, it is possible to extract the history information embedded in each color component data.

In the above, an example in which the device ID is used as the history information has been described. However, the present invention is not limited to this, and an ID representing a user or a manufacturer of the device may be used. Also, copyright information can be included in the history information.

As described above, it is possible to embed a plurality of types of digital watermark information (device ID) in each color. Further, by embedding the latest flag, even when a plurality of pieces of digital watermark information are embedded as history information, the latest digital watermark information can be easily determined. further,
Digital watermark information can be added to an image so that newer information remains preferentially.

[0077]

[Other Embodiments] 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.), an apparatus (for example, a copying machine) Machine, facsimile machine, etc.).

Further, an object of the present invention is to supply a storage medium (or a recording 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 a computer (a computer) of the system or the apparatus. It is needless to say that the present invention can also be 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. Also,
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also the operating system (OS) running on the computer based on the instructions of the program code.
It goes without saying that a case where the functions of the above-described embodiments are implemented by performing some or all of the actual processing, and the processing performs the functions of the above-described embodiments.

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. Needless to say, the CPU included 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.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowcharts described above.

[0081]

As described above, according to the present invention,
A function of embedding as much additional information as possible in an input color image can be provided.

Further, with respect to image data passed through a plurality of devices, it is possible to recognize the passed device.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a processing path of image data according to an embodiment;

FIG. 2 is a diagram showing a concept of an embedding order of history information;

FIG. 3 is a photograph showing an example of a dither pattern used for embedding digital watermark information;

FIG. 4 is a photograph showing an example of a dither pattern used for embedding digital watermark information;

FIG. 5 is a photograph showing an example of a dither pattern used for embedding digital watermark information,

FIG. 6 is a photograph showing an example of a dither pattern used for embedding digital watermark information,

FIG. 7 is a photograph showing an example of a dither pattern used for embedding digital watermark information;

FIG. 8 is a conceptual diagram showing a threshold array of a first or second dither pattern when M = 5;

FIG. 9 is a diagram showing a threshold array of a third or fourth dither pattern when M = 5;

FIG. 10 is a diagram showing an example of a bit string of history information;

FIG. 11 is a flowchart showing a processing example of embedding history information in an image,

FIG. 12 is a diagram showing a state in which color component data is divided into blocks of M × M pixels.

FIG. 13 is a diagram showing an example of correspondence between a bit sequence, a random number sequence, and an index number of a block;

FIG. 14 is a flowchart illustrating an example of processing for extracting history information embedded as electronic watermark information in an output image.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G09C 5/00 B41J 29/00 Z 5C079 H04N 1/60 H04N 1/40 D 5J104 1/46 1/46 Z 9A001 F term (Ref.) LA34 LA40 LC04 MA01 NA15 5J104 AA14 CA02 DA05 9A001 DD15 HH28 JJ19 LL03

Claims (10)

[Claims] 1. An input unit for inputting image data having a plurality of color components, wherein at least one of the plurality of color components indicates that the first information and the first information are the latest information. An image processing apparatus comprising: an embedding unit that embeds the second information as digital watermark information. 2. The embedding means embeds, as digital watermark information, second information indicating that the latest information is not included in a color component different from the color component in which the first information is embedded. 2. The image processing apparatus according to claim 1, wherein: 3. The image processing apparatus according to claim 1, wherein the first information is information for specifying an apparatus. 4. The apparatus according to claim 1, wherein the embedding unit embeds digital watermark information when at least one color component of the plurality of color components is binarized. Image processing device. 5. The digital watermark information according to claim 1, wherein the embedding unit embeds digital watermark information by switching a dither pattern used when binarizing at least one color component of the plurality of color components. 5. The image processing device according to claim 4. 6. An image data having a plurality of color components is input, and at least one of the plurality of color components has first information and second information indicating that the first information is the latest information. An image processing method characterized in that information is embedded as digital watermark information. 7. A recording medium on which a program code for image processing is recorded, wherein the program code includes at least a code for inputting image data having a plurality of color components, and at least one color of the plurality of color components. A recording medium comprising, as components, a code for a step of embedding first information and second information indicating that the first information is the latest information as digital watermark information. 8. An input unit for inputting image data having a plurality of color components; a processing unit for dithering each of the plurality of color components; and selectively applying a plurality of dither patterns to the dither processing by the processing unit. Embedding means for embedding the first information in the first color component of the plurality of color components and the second information in the second color component as digital watermark information. Image processing device. 9. A method for inputting image data having a plurality of color components and selectively applying a plurality of dither patterns to each of the plurality of color components when dithering the plurality of color components. An image processing method comprising embedding first information in one color component and second information in a second color component as digital watermark information. 10. A recording medium on which a program code for image processing is recorded, wherein the program code includes at least a code for inputting image data having a plurality of color components; By selectively applying a plurality of dither patterns to the dithering process, the first information for the first color component of the plurality of color components, and the second information for the second color component. And a code for a step of embedding the above information as digital watermark information.