JP2005210622A - Image processing apparatus and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus and an image processing method, by which maximum additional information can be multiplexed in an image, while minimizing the deterioraration of image quality and the additional information can be stably restored, even if the image is printed on a paper sheet. <P>SOLUTION: In the image processing apparatus, which composites additional image data to be embedded embedding based on additional information to image data to be processed to generate composite image data, a control section 11 determines a predetermined feature amount from the image data and generates the additional image data, based on the predetermined feature amount and on the error correction capability of an encoding method which used to an additional information encoding means for encoding the additional information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus and method for embedding information in an image expressed in multiple gradations, and an apparatus and method for detecting information embedded in an image.

  In recent years, so-called electronic watermark technology has been studied and put into practical use, such as synthesizing additional information with image data (image data to be processed) in a manner that cannot be easily visually identified. Image data obtained by combining such electronic watermarks is read and decoded later, and is subjected to predetermined processing such as document authentication.

  However, image data formed on a paper medium includes D / A, A / D conversion by printing and scanning, color conversion, binarization processing by a screen, resolution conversion caused by a difference in resolution between a printer and a scanner, and scanning In addition to skew (tilt), there are various image quality degradation factors such as noise, pixel position shift (in-plane unevenness) due to mechanical operation of printers and scanners, and aberrations when using a digital camera as an input device. Information cannot be read stably.

  Therefore, when the information is encoded with a binary number of “0” or “1”, each of the two types of pattern images as shown in FIG. 10 is associated with each of the codes “0” and “1”. In addition, for the code string obtained by encoding, pattern images corresponding to the respective codes included in the code string are sequentially selected and arranged in a predetermined order to obtain an additional image. You can gain resistance to.

  That is, the pattern image shown in FIG. 10 defines a basic pattern (A) meaning “1” and a basic pattern (B) meaning “0” as shown in FIG. The values (pixel values) of these elements are represented by equations (1) or (2) shown in FIG. 11C (in these equations, C is the embedding strength, α is the attenuation factor, and It is obtained by multiplying the value defined by the user). In the equations (1) and (2), X and Y are the values of the coordinates (X, Y) of each pixel when the center of the pattern image is (X, Y) = (0, 0).

As a result of this multiplication, each pattern image shown in FIG. 10 is generated based on each of FIGS. 11 (A) and 11 (B). In FIG. 10, for the sake of illustration, the difference in density is indicated by the difference in hatching. These pattern images
(1) The result of adding the corresponding pixels of both pattern images is the same predetermined value (for example, “0”).
(2) The result of adding all the pixels in each pattern image is the same predetermined value (for example, “0”).
(3) Each pattern image has two discontinuous lines (called edges) of pixel values that pass through the center of the image and have different directions. In the example of FIG. 10, edges are formed orthogonally in the vertical and horizontal directions.
(4) The absolute value of the pixel value of each pattern image is the largest at the center and decreases as the distance from the center increases.
It has the characteristics. In this way, by expressing the code by a pattern having an area, the resistance to each image quality deterioration factor is acquired, while the density of the image is prevented from changing greatly after composition (by the characteristics of (1) and (2)). ) The pattern image can be easily detected and the decoding process is simplified (by the features (2) and (3)), and the occurrence of an edge between patterns is prevented (by the feature (4)). Becomes visually inconspicuous.

  When decoding an image obtained by synthesizing this pattern image, a sum of pixel values after synthesis corresponding to each quadrant divided by edges in the pattern image (R1 to R4 for the first to fourth quadrants) is calculated. For example, when R1> R2 and R1> R4 and R3> R2 and R3> R4, it is determined that the code is “1”. That is, decoding can be performed by comparing the sum of pixel value groups for each quadrant.

  However, when such a pattern image is used, depending on the content of the image data to be combined, it may be difficult to read each pattern image from the combined image. That is, there is a portion including high-frequency components in the image data to be combined. For example, as shown in FIG. 12, the pixel value has a boundary from the edge portion of the pattern image to be combined as a boundary from the first quadrant (the upper right block). If the brightness is “low”, “high”, “high”, “high” on average in order (in the angular direction) to the four quadrants (lower right block), the symbol “1” is used here. As a result of synthesizing the pattern image corresponding to, the values of R1 to R4 are all “high”, there is no significant difference between the values of R1 to R4, and it is determined that the value is “1”. It becomes practically difficult.

  Therefore, when the embedding method and decoding method as described above are used, it is easy to detect the signal embedded in the flat part of the image, and detection of the signal embedded in the other part, that is, the edge part or the complicated pattern part. Becomes difficult.

  In such a case, if additional image data is generated and synthesized with a uniform intensity without considering the characteristics of the embedding target image, stable decoding cannot be performed, or the image is deteriorated more than necessary.

  As an example for partially solving such a problem, the inventor has already controlled the intensity C of a block-shaped additional image pattern (hereinafter referred to as a cell) according to the feature amount obtained from the block image at the synthesis destination. Has been reported. However, when embedding additional information with a predetermined information amount in a predetermined image size, it is not always necessary to apply the embedding strength according to the feature amount to all cells, and there is room for improvement in image quality.

  That is, when additional information of a predetermined amount of information is encoded into a predetermined image size and the additional information is synthesized in the image, since there is a correction capability depending on the error correction code adopted as the encoding method, all It is not necessary to identify the correct embedded information from other cells, so for cells that are expected to be difficult to identify, create a stronger strength to facilitate identification depending on the situation of surrounding cells There is no need to synthesize the added image data.

  There are several attempts to use error correction effectively to improve reading stability. For example, the technique described in Patent Document 1 below discloses a technique that enables embedding of maximum information by determining the capability of an error correction code according to the property of the information to be embedded.

In the technique described in Patent Document 2 below, the maximum amount of paper used is changed by changing the error correction code used depending on the type of paper used for printing (for example, plain paper, glossy paper, etc.). Discloses a technique for obtaining the amount of embedded information.
JP 2002-374402 A JP 2002-218207 A

  However, in the above conventional technique, embedding is not performed in consideration of the characteristics of the image data on the side to be combined (image data to be processed) and the characteristics of the code used for encoding the additional information. There is a problem that sufficient effects cannot be obtained in terms of suppression of image degradation and accurate decoding.

  The present invention has been made in view of the above-described circumstances. Even when an image is printed on paper, the maximum additional information can be multiplexed in the image while minimizing image quality degradation, and is stable. An object of the present invention is to provide an image processing apparatus and an image processing method that can restore additional information.

  In order to achieve the above object, the present invention provides an image processing apparatus that synthesizes additional image data based on additional information to be embedded with image data to be processed and generates combined image data. An image input means for inputting the image data, an additional information means for inputting the additional information, an additional information encoding means for encoding the additional information, and a predetermined feature amount from the input image data Characteristic amount calculating means for calculating the additional image data based on the predetermined characteristic amount and the error correction capability of the encoding method used in the additional information encoding means. It is characterized by that.

  Here, the predetermined feature amount is an amount determined based on a dispersion of pixel values of predetermined partial image data or a difference between predetermined pixel values obtained by equally dividing the predetermined partial image data. Features. Further, the additional image generation means changes the intensity of the additional image data in accordance with the predetermined feature amount.

  In addition, the present invention is an image processing apparatus that synthesizes additional image data based on additional information to be embedded with image data to be processed, and generates combined image data, the image data Image input means for inputting the image data, image correction means for correcting the input image data, additional information means for inputting the additional information, additional information encoding means for encoding the additional information, and the corrected Additional image data is generated based on the feature amount calculating means for calculating a predetermined feature amount from the obtained image data, the predetermined feature amount, and the error correction capability of the encoding method used in the additional information encoding means. And an additional image generating means.

  Here, the image correction unit corrects the image data so that the pixel value of the additional image data generated by the additional image generation unit falls within a predetermined range. The predetermined feature amount is an amount determined based on a variance of pixel values of the partial image data of the corrected image or a difference between predetermined pixel values obtained by equally dividing the partial image data of the corrected image. It is characterized by being. Further, the additional image generation means changes the intensity of the additional image data in accordance with the predetermined feature amount.

  Further, the present invention is an image processing method for causing a computer to synthesize additional image data based on additional information to be embedded with image data to be processed, and to generate combined image data, A step of inputting the image data; a step of inputting the additional information; a step of encoding the additional information; a step of calculating a predetermined feature amount from the input image data; and the predetermined feature amount And generating additional image data based on the error correction capability of the encoding method used when encoding the additional information.

  Furthermore, the present invention is an image processing program that uses a computer to synthesize additional image data based on additional information to be embedded with image data to be processed to generate composite image data. A procedure for inputting the image data to the computer; a procedure for inputting the additional information; a procedure for encoding the additional information; and a procedure for calculating a predetermined feature amount from the input image data; And a procedure for generating additional image data based on the predetermined feature amount and an error correction capability of an encoding method used when encoding the additional information.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings.

  As shown in FIG. 1, the image processing apparatus according to the present embodiment includes a control unit 11, a storage unit 12, an operation unit 13, a display unit 14, and an input / output unit 15. The control unit 11 operates in accordance with an image processing program stored in the storage unit 12, and synthesizes additional image data based on additional information that is an embedding target with image data that is a processing target, and generates a composite image Process to generate data. The specific contents of this processing will be described in detail later.

  The storage unit 12 includes a computer-readable recording medium that holds a program executed by the control unit 11. The storage unit 12 also operates as a work memory that stores various data generated in the course of image processing by the control unit 11.

  The operation unit 13 is a keyboard, a mouse, or the like, and outputs the operation content to the control unit 11 in response to a user operation. The display unit 14 presents information to the user in accordance with an instruction input from the control unit 11.

  The input / output unit 15 outputs data input from the outside to the control unit 11. The input / output unit 15 outputs data to an external device such as a printer in accordance with an instruction input from the control unit 11.

  Here, specific contents of the processing of the control unit 11 will be described. The control unit 11 stores the image data to be processed in the storage unit 12, and synthesizes the additional image data with this image data according to a program described below.

  Functionally, the program executed by the control unit 11 includes an image data analysis unit 21, an additional information encoding unit 22, an additional image generation unit 23, and a synthesis unit 24, as shown in FIG. It is configured.

  The image data analysis unit 21 divides an image to be embedded (processing target) into cells having the same size as the pattern image to be synthesized, calculates a feature quantity A obtained by analyzing the image for each cell, If the feature amount A exceeds a predetermined threshold value, the value is stored in each element such as a table. Specifically, as shown in FIG. 4, if a two-dimensional array having the same number of elements as the number of cells that can be arranged in an image is used as a table, the value of each element, that is, the value stored in each element of the two-dimensional array Thus, the relationship between the cell position and the feature amount A of the cell can be stored.

  Next, the two-dimensional array is scanned in the raster scan order (the order obtained by scanning the lines obtained by scanning from the left to the right from the top to the bottom), and an error used in the additional information encoding unit 22 described later. The number of element values equal to the code length of the correction code is extracted. When the number of cells whose extracted element values are not 0 (zero) is less than or equal to the number of error-correctable bits of the error correction code, the values of those elements are also rewritten to 0 (zero). When the number of cells whose element value is not 0 (zero) exceeds the number of correctable bits of the error correction code, cells whose element value is other than 0 (zero) and whose element value is smaller are sequentially , The element value is stored for the number of cells obtained by subtracting the correctable number of bits from the number of cells whose element value is not 0 (zero), and all the element values are set to 0 (zero) for the other cells. Rewrite to

  Specifically, if a BCH code (parameter n is the code length, parameter k is the number of information bits, and parameter t is the number of bits that can be corrected) is used as the encoding method, the elements of the two-dimensional array are n in the raster scan order. If there are t cells whose element value is not 0 (zero), the values stored there are all 0 (zero), and conversely, the element value is 0 (zero). ) If there are t1 cells (t1> t), the element value is other than 0 (zero) and only the t1-t element values from the smallest are left, and the other element values are all 0 Rewrite to (zero). The feature amount A is a scale representing the difficulty of embedding additional information or the difficulty of identification (decoding) at the time of reading, and the calculation thereof will be described in detail later.

  The additional information encoding unit 22 encodes the additional information based on a predetermined encoding method. In the above description, the BCH code is taken as an example of the encoding method, but the encoding method is not limited to this.

  The additional image generation unit 23 generates additional image data based on the encoded sequence of additional information encoded by the additional information encoding unit 22 and the two-dimensional array stored by the image data analysis unit 21. Specifically, as shown in FIG. 3, the additional image generation unit 23 corresponds to a pattern image generation unit 31 that generates a plurality of pattern images corresponding to each code and each code constituting the code string. A pattern selection unit 32 that outputs a pattern image while selecting it, and a pattern arrangement unit 33 that arranges the selected pattern image are included.

  The pattern image creation unit 31 creates pattern images corresponding to the codes “0” and “1” as shown in FIG. 10, and the image data analysis unit 21 creates the intensity (size) thereof. The determination is made with reference to the two-dimensional array. Specifically, if an image pattern as shown in FIG. 10 is generated by the equations (1) and (2) in FIG. 11C, a predetermined feature amount A created in advance as shown in FIG. 5 and the table regarding the corresponding embedding strength C and attenuation rate α and the two-dimensional array, the value of each element of the two-dimensional array is set as the predetermined feature amount A in FIG. Image patterns are sequentially created at a rate α. Note that the table shown in FIG. 5 may be obtained by experimenting in advance the strength and attenuation rate that facilitate identification by the identification method described later.

  The pattern selection unit 32 sequentially selects a pattern image corresponding to each code included in the code sequence from among a plurality of pattern images output by the pattern image creation unit 31 while referring to the code sequence that is the encoding result of the additional information. Select (in order of code string) and output.

  When the size of the image data is (X, Y) and the size of the image pattern is (W, H), the pattern arrangement unit 33 converts the pattern image output by the pattern selection unit 32 to INT (X / W) × INT Pattern images are arranged in (Y / H) matrix. Here, the arrangement order is the same as the raster scan.

  As described above, the additional image data can be generated based on the feature amount of the image data and the error correction capability of the encoding method used in the additional information encoding unit 22.

  The synthesizing unit 24 synthesizes the additional image generated by the additional image generating unit 23 into a range corresponding to the corresponding macroblock region on the image data to be processed. That is, the composition unit 24 adds the pixel value of the additional image to the corresponding pixel value of the processing target image data stored in the storage unit 12 and outputs the result. Here, when the added value exceeds the maximum value (for example, 255) of the pixel value, the value is set to the maximum value, and when the added value falls below the minimum value (for example, 0) of the pixel value, the value is set to the minimum value. Set to.

  Next, the image data after combining the additional images in this way is output to the printer via the input / output unit 15 by the processing of the control unit 11, and the printer receives the input of the image data and is represented by the image data. The image is formed on a medium such as paper.

[Decryption process]
Next, a method for decoding additional information from the image thus formed on the medium will be described. An apparatus for decoding the additional information can also be realized using the image processing apparatus shown in FIG. That is, a scanner (not shown) may read an image formed on the medium to obtain image data, and the image data may be processed and decoded by the control unit 11. Hereinafter, a case where decoding processing is performed using the image processing apparatus illustrated in FIG. 1 will be described as an example.

  As shown in FIG. 6, the program of the control unit 11 for performing the decoding process functionally includes an image data holding unit 41, an inclination correction unit 42, a cell size estimation unit 43, and a cell position detection unit 44. And an additional information identifying unit 45 and an additional information decoding unit 46.

  Image data read by a scanner (not shown) is held in the storage unit 12 by the image data holding unit 41. When image data input from a scanner or the like is compressed here, the compressed image data is expanded or restored to the original image data (bitmap data). The inclination correction unit 42 corrects the inclination of the image data held by the image data holding unit 41 by a widely known method.

  The cell size estimation unit 43 estimates the size of a cell that is a unit of the additional image from the image data after the inclination correction. Specifically, when the additional image includes an edge as shown in FIG. 10, the cell size is estimated based on the edge interval by detecting this edge. That is, an edge extraction image is generated by extracting only high-frequency components whose pixel values change rapidly, and the cell size is estimated from the peak position of the autocorrelation function related to the edge extraction image. By this process, the size of the image data changes in the process from printing to reading, and the decoding process can be performed even if the cell size changes.

  The cell position detection unit 44 detects the position of each pattern representing the additional image (that is, the position of the cell) from the image data based on the estimated cell size. The detection of the cell position corresponds to, for example, polarity information (see FIG. 11A or 11B) in one of the pattern images representing the respective codes shown in FIGS. Then, for example, a binary pattern in which “−1” is black and “1” is white is generated, and this is used as a mask to generate mask image data arranged in a matrix according to the cell size. Then, a correlation calculation is performed between the mask image data and the image data held in the image data holding unit 41, and a point where the result of the correlation calculation becomes a maximum or a minimum is extracted. Project in the vertical direction. Then, when there is an intersection of two edges at the center of the pattern image as shown in FIG. 10, since the maximum and minimum of the correlation calculation result appear at the approximate center, the estimation is performed around the projection position of the maximum and minimum positions. The position moved in the horizontal or vertical direction by ± 1/2 of the obtained cell size can be defined as the boundary position between the cells.

  Here, the reason why only the mask image corresponding to one of the pattern images is generated is that the polarities of the pattern images in FIG. 11 are opposite to each other.

  The additional information identification unit 45 is controlled by an additional information decoding unit 46 described later, and an additional image embedded in a cell whose position and size are estimated by the cell size estimation unit 43 and the cell position detection unit 44. Identify. Specifically, this additional image is identified based on the magnitude relationship of the sum of the pixel values of the four regions divided by lines along the edges included in the pattern as follows.

  Since the pattern image of FIG. 10 passes through the center and is divided into four regions by edges orthogonal to the horizontal and vertical directions, the additional information identification unit 45 correspondingly performs the cell size estimation. Each of the cell images included in each cell defined by the unit 43 and the cell position detection unit 44 is divided into regions R1 to R4 as shown in FIG. 7A, and each pixel in each region R1 to R4 is divided. The sum of the values (SP1 to SP4) is calculated. When the cell width or height is an odd number, as shown in FIG. 7B, the cell passes through the center of the cell, and the height direction (when the width is odd) and the width direction (the height is odd). In other words, the above-described regions R1 to R4 may be divided except for the pixels extending in the case).

Then, based on the magnitude relationship from SP1 to SP4, it is determined whether the code represented by the pattern image synthesized in the cell is “1” or “0” (or cannot be discriminated). In particular,
(1) If ((SP1> SP2) &&(SP1> SP4) &&(SP3> SP2) &&(SP3> SP4)), the code is “1”. “&&” means an AND condition, that is, a condition in which the preceding and following conditions are connected by “and”.
(2) If ((SP2> SP1) &&(SP3> SP2) &&(SP4> SP1) &&(SP4> SP3)) instead of (1), the code is “0”.
As described above, the code represented by the pattern image synthesized in the cell is determined by satisfying a plurality of conditions.

  FIG. 8 is an explanatory diagram illustrating an example of pattern image identification processing in the additional information identification unit 45. In FIG. 8, the relatively small value is hatched. If the pixels in the cell before the pattern image synthesis are within a certain range of values such as almost the same value (in other words, the image is flat), if the pattern image representing the code “1” is synthesized, R1 Since the pixel value in the part of R3 and R3 becomes larger and the pixel value in the part of R2 and R4 becomes smaller, even after printing or scanning ((SP1> SP2) && (SP1> SP4) && (SP3 > SP2) && (SP3> SP4)) is highly likely to be satisfied, and determination based on the above conditions is possible.

  If the processing target image data includes a high-frequency component and this is in one of the cells, the pixel value after synthesis of the additional image does not necessarily satisfy the above condition in this cell. Become. Therefore, for example, as shown in FIG. 9, the above condition (1) also corresponds to the case where the pixel value in the upper part of the cell is a relatively small value and the pixel value in the lower part of the cell is a relatively large value. If ((SP1> SP4) && (SP3> SP2) && (SP3> SP4)) is satisfied instead of (2), it is determined that the pattern image in the cell represents the code “1”. May be. Similarly, it corresponds to the case where the pixel value in the upper part of the cell is a relatively large value and the pixel value in the lower part of the cell is relatively small, or when the pixel value changes between right and left of the cell. Each condition may be determined.

  In this way, the additional information identification unit 45 sequentially identifies each cell in the order of raster scanning, and sequentially outputs the corresponding codes. Needless to say, the above condition (1) or (2) can be easily established if an additional image pattern having a high strength is synthesized at the time of embedding the additional information.

  The additional information decoding unit 46 obtains additional information by decoding a sequence of codes sequentially output by the additional information identifying unit 45 based on a predetermined encoding method.

[Calculation of predetermined feature A]
Next, an example of calculation of the predetermined feature amount A of the image data analysis unit 21 in the processing of the control unit 11 at the time of encoding will be described. The predetermined feature amount A is defined in association with the decoding method. For example, in decoding, as described above, when the code represented by each pattern image is identified using the sum of the pixel values included in each region R1 to R4 in the cell, as described above, If there is an edge in advance in a portion corresponding to a cell of image data, it becomes difficult to identify, and an indistinguishable state may occur. On the other hand, if a pattern image is created with a strong intensity when synthesizing the additional image pattern in advance, the number of cells that cannot be identified is reduced, but the original image is deteriorated more than necessary. In addition, the method of changing the strength for each cell according to the degree of identification difficulty is good for the purpose of embedding more additional information, but if the amount of additional information is constant, the viewpoint of image quality degradation Is not preferable.

  Therefore, in this case, cells that are difficult to identify with the standard pattern strength are predicted, and only the minimum necessary number of cells are taken into account, taking into account the prediction results and the correction capability of the error correction code that has been previously adopted as the encoding method. It is preferable in terms of image quality and reading stability to synthesize a pattern image having a slightly higher intensity than the standard. That is, when decoding as described above is performed, the flatness in the image, that is, the small number of edges is calculated as the predetermined feature amount. Specifically, the image is divided into cell sizes, and the dispersion of pixel values within each cell (the larger the value, the less flat) is determined and used as a predetermined feature amount. Even if the variance is large, when the cell is divided into the above-described regions R1 to R4, the difference of pixel values | SP1 + SP3- (SP2 + SP4) | (| · | represents an absolute value) is a predetermined threshold value. If it is smaller, identification is easy. Therefore, the value of | SP1 + SP3- (SP2 + SP4) | may be set as the predetermined feature amount. That is, this value indicates the difficulty of identification. In order to facilitate the identification of cells that are large and difficult to identify, it is necessary to synthesize a pattern image with a higher intensity.

  Further, instead of the predetermined feature amount, the ratio of the number of cells in which the variance value of each cell is equal to or greater than a predetermined threshold with respect to all the cells in the image, or | SP1 + SP3- (SP2 + SP4) | The ratio of the number of cells whose value is equal to or greater than a predetermined threshold is defined as a predetermined feature amount, and the BER (Bit Error Rate: bit) that can be decoded by the error correction code used as the encoding method The pattern image can be synthesized in consideration of the error rate.

  In addition, when a pattern image different from the pattern image demonstrated so far is used, or when a decoding method differs, it is also preferable to set a predetermined feature amount according to it.

[Operation]
The image processing apparatus according to the present embodiment is configured as described above. Therefore, with respect to the image data to be subjected to synthesis, the nature of the image data and the correction capability of the error correction code used as the encoding method are described. Based on the above, a pattern image that is stronger than usual is created for only the minimum number of cells, and an operation for synthesizing it with the image is performed. As a result, it is possible to facilitate decoding while suppressing image quality deterioration of the image.

[Other variations]
Instead of the functional block shown in FIG. 2, a functional block as shown in FIG. 13 may be used. In FIG. 13, an image adjusting unit 25 is added to the functional blocks shown in FIG. The image adjustment unit 25 lowers the dynamic range in advance so that the added value does not exceed the maximum pixel value (for example, 255) at the time of additional pattern synthesis or falls below the minimum pixel value (for example, 0) at the time of subtraction. Is.

  In the description of the image data analysis unit 21, the number t of error correctable bits t of the employed error correction code is compared with the number of cells having a feature value exceeding a predetermined value in n cells. In the case of a beam printer, a value t0 smaller than t may be used for comparison in consideration of scattering of toner, scratches on the photosensitive member, and dirt and fading after printing.

  Furthermore, the pattern used for generating the additional image is not limited to that shown in FIG. 10, and may be any pattern as long as it has edges in at least two directions.

1 is a configuration block diagram illustrating an example of an image processing apparatus according to an embodiment of the present invention. It is a functional block diagram showing an example of the encoding process in the image processing apparatus of implementation of this invention. It is explanatory drawing showing the example of a setting of an encoding method. It is a table which records the feature-value of each cell. It is a table which shows an example of the combination of the pattern intensity | strength and attenuation factor for the feature quantity and cell identification becoming easy. It is a functional block diagram showing the example of the decoding process in the image processing apparatus of implementation of this invention. It is explanatory drawing showing the example of a division | segmentation of a cell. It is explanatory drawing showing the example of the height of a pixel. It is explanatory drawing showing the example of the height of a pixel. It is explanatory drawing showing the example of the pattern used for the production | generation of additional image data. It is explanatory drawing showing the example of a pattern production | generation. It is explanatory drawing showing the example of the height of the pixel in a cell. It is a functional block diagram showing another example of the encoding process in the image processing apparatus of implementation of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Control part, 12 Storage part, 13 Operation part, 14 Display part, 15 Input / output part, 21 Image data analysis part, 22 Additional information encoding part, 23 Additional image generation part, 24 Composition part, 25 Image adjustment part, 31 Pattern image creation unit, 32 pattern selection unit, 33 pattern arrangement unit, 41 image data holding unit, 42 tilt correction unit, 43 cell size estimation unit, 44 cell position detection unit, 45 additional information identification unit, 46 additional information decoding unit.

Claims (9)

An image processing device that synthesizes additional image data based on additional information to be embedded with image data to be processed, and generates combined image data,
Image input means for inputting the image data;
Additional information input means for inputting the additional information;
Additional information encoding means for encoding the additional information;
Feature quantity computing means for computing a predetermined feature quantity from the input image data;
An image processing apparatus comprising: an additional image generation unit configured to generate additional image data based on the predetermined feature amount and an error correction capability of an encoding method used in the additional information encoding unit.   The image processing apparatus according to claim 1, wherein the predetermined feature amount is based on a distribution of pixel values of predetermined partial image data or a difference between predetermined pixel values obtained by equally dividing the predetermined partial image data. An image processing apparatus characterized in that the amount is determined.   The image processing apparatus according to claim 1, wherein the additional image generation unit changes an intensity of the additional image data in accordance with the predetermined feature amount. An image processing device that synthesizes additional image data based on additional information to be embedded with image data to be processed, and generates combined image data,
Image input means for inputting the image data;
Image correcting means for correcting the input image data;
Additional information input means for inputting the additional information;
Additional information encoding means for encoding the additional information;
Feature amount calculating means for calculating a predetermined feature amount from the corrected image data;
An image processing apparatus comprising: an additional image generation unit configured to generate additional image data based on the predetermined feature amount and an error correction capability of an encoding method used by the additional information encoding unit.   5. The image processing apparatus according to claim 4, wherein the image correction unit corrects the image data so that a pixel value of the additional image data generated by the additional image generation unit is within a predetermined range. An image processing apparatus.   5. The image processing apparatus according to claim 4, wherein the predetermined feature amount is a predetermined pixel value obtained by dividing a pixel value of partial image data of the corrected image or by equally dividing the partial image data of the corrected image. An image processing apparatus characterized in that the amount is determined based on a difference.   5. The image processing apparatus according to claim 4, wherein the additional image generation unit changes the intensity of the additional image data in accordance with the predetermined feature amount. An image processing method for synthesizing additional image data based on additional information to be embedded with image data to be processed, and generating combined image data,
Inputting the image data;
Inputting the additional information;
Encoding the additional information;
Calculating a predetermined feature amount from the input image data;
An image processing method comprising: generating additional image data based on the predetermined feature amount and an error correction capability of an encoding method used when encoding the additional information. An image processing program for synthesizing additional image data based on additional information to be embedded with respect to image data to be processed using a computer, and generating combined image data.
A procedure for inputting the image data;
A procedure for inputting the additional information;
A procedure for encoding the additional information;
A procedure for calculating a predetermined feature amount from the input image data;
A procedure for generating additional image data based on the predetermined feature amount and an error correction capability of an encoding method used when encoding the additional information;
An image processing program for executing

Images