JP4345221B2 - Image generation system, recorded image, and image recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image generation technique for concealing an image including information to be kept secret, and more particularly, to an image generation system and an image recording material that can be suitably used for concealment by dispersing the image.
[0002]
In this specification, an image including information to be kept secret (information to be kept and recorded) is called a “secret image”, and a plurality of images in which the “secret images” are distributed are called “tally images”. The recorded material obtained based on the “tally image” will be referred to as “tally”. In addition, an operation for making a secret image distinguishable (visible) by human eyes by superimposing tally images is expressed as “reproduction”, and an image to be reproduced is called “reproduction image”.
[0003]
[Prior art]
A conventional technique for concealing an image representing information will be described below with reference to a document describing it.
[0004]
(1) Taku Kato, Hideki Imai: “Extended configuration method of the visual decryption secret sharing method”: IEICE Transactions A, Vol. J79-A, No. 8, pp. 1344-1351
In this technique, a plurality of black and white random images are formed, and when these are superimposed, a significant image is reproduced. This is a technique capable of distributing secrets by combining not only two images but also three or more images. If secrets are distributed to a plurality of images, it is impossible to know any information about other images even if only one of the images of the plurality of images is obtained. Therefore, only a person who can obtain a plurality of sheets at the same time can reproduce the information, and the secret can be safely distributed and stored.
[0005]
(2) Japanese Patent Laid-Open No. 9-248935
In this technique, another additional image is superimposed and recorded on a certain main image, and the additional image is reproduced by overlapping the image with the pattern image. It is characterized in that information can be recorded in a color image in a form that is difficult for humans to perceive.
[0006]
(3) Japanese Patent Application No. 2000-82513 (filed by Toppan Printing Co., Ltd.)
In this technique, a secret image is dispersed and stored in a plurality of black and white or color images, and the secret image is reproduced when the dispersed images are superimposed.
[0007]
(4) Kokoo Matsui: “Digital Watermark”: Journal of the Institute of Image Electronics Engineers of Japan, Vol. 26, No. 3 (1997)
In this technique, a digital watermark is recorded in digital data, and the digital watermark is read by performing a predetermined decoding process. In particular, as a method of putting a digital watermark in a still image, methods such as “pixel space use type”, “frequency domain use type”, and “statistics use type” are known.
[0008]
[Problems to be solved by the invention]
In the technique (1), it is composed only of black and white random patterns, and rich expression by color is impossible.
[0009]
In the technique (2), information is recorded in a color image in a form that is difficult for humans to perceive an image to be concealed, but the concealed image itself is not colorized. In addition, the types of color images that can be used are limited, and there is a problem that they cannot be applied to complex color images.
[0010]
By the way, the technique (3) described above is such that the same effect as that of the original one can be easily obtained by copying with a copying machine, or the recording medium needs to be transparent. This is to make up for the technical drawbacks of the techniques 1) and (2), but it does not color the concealed image itself as in (2). There is also a description of how to use other colors, red and yellow, instead of white and black. However, there was a limit to the appearance of the color simply by switching colors.
[0011]
In the technique (3), digital data is targeted, and an arithmetic device such as a computer is required for both encoding and decoding, and information cannot be easily decoded. In addition, since an arithmetic device is required, it has been difficult to reduce the cost.
[0012]
An object of the present invention is to eliminate the drawbacks of the related art and to record various information in a distributed manner and to easily reproduce the information.
[0013]
The invention according to claim 1 of the present invention is registered in an image data input unit for inputting secret image data, secret image data input from the image data input unit, and a color set data table stored in an external or internal memory. On the basis of the color set data corresponding to the black pixel portion and the white pixel portion of the secret image data in which two or more pixel values corresponding to the tally number in one set of tally are one set (one set), Generate pixel data of two or more tally images for each pixel of secret image data The secret image data is a random image that cannot be read alone. A central processing control unit having a program memory for controlling a process from the input of a secret image for generating tally image data to data generation and recording of tally images 2 and 3, and an image data memory for storing the generated tally image data Department, An image generation system characterized by comprising the above.
[0014]
Next, an invention according to claim 2 of the present invention is the image generation system according to claim 1, wherein each color set data of the color set data table is stored. Is 2 or more Several types of color sets are provided, and for each pixel of the secret image data, one color set is selected from the color set, and pixel data of two or more tally images is generated to generate tally image data. This is an image generation system.
[0015]
Next, the invention according to claim 3 of the present invention is the image generation system according to claim 1, wherein each color set data of the color set data table is stored. Is 2 or more There are several kinds of color sets, and for each pixel of the secret image data, one type of color set is selected from among the color sets using random numbers to generate pixel data of two or more tally images to generate tally images An image generation system characterized by generating data.
[0016]
Next, the invention according to claim 4 of the present invention is registered in the image memory unit for storing the secret image data, the secret image data input from the image memory unit, and the color set data table stored in the external or internal memory. One pixel of the secret image data based on the color set data of the black pixel portion and the white pixel portion of the secret image data in which one or more pixel values corresponding to the number of tally in one set of tally are set. 2 or more for each There are random images that cannot be read by themselves. Tally generating unit for generating tally image data, and image data recording for recording tally image data generated by the tally generating unit Department, An image generation system characterized by comprising the above.
[0017]
Next, the invention according to claim 5 of the present invention is the image generation system according to claim 4, wherein each color set data of the color set data table is stored. Is 2 or more Several types of color sets are provided, and for each pixel of the secret image data, one color set is selected from the color set, and pixel data of two or more tally images is generated to generate tally image data. This is an image generation system.
[0018]
Next, an invention according to claim 6 of the present invention is the image generation system according to claim 4, wherein each color set data of the color set data table is stored. Is 2 or more Two or more tally image pixels are provided by selecting several types of color sets and selecting one color set from the color sets based on a random value generated from a random number generator for each pixel of secret image data An image generation system characterized by generating tally image data by generating data.
[0019]
Next, the invention according to claim 7 of the present invention is the one generated based on the secret image data and the color set data by the image generating system according to any one of claims 1 to 6. Each of the tally images based on the plurality of tally image data is output and recorded by using a hard copy output unit on each of two or more sheets.
[0020]
Next, the invention according to claim 8 of the present invention is the one generated by the image generation system according to any one of claims 1 to 6 based on the secret image data and the color set data. A plurality of tally image data is recorded as electronic data as described above.
[0021]
[Action]
In the present invention, in the method of storing the image in a distributed manner, the secret information itself or the secret image including the secret information is superimposed by overlaying a random color image instead of the expression by the black and white contrast as in the technique (1). scatter. The expression in color is very rich compared to black and white, and not only looks good, but it is also fun to see and enhance entertainment.
[0022]
Furthermore, compared with the case of black and white, copying with a copying machine or the like can be made difficult, and the effect of preventing forgery can be enhanced. In the conventional method, a plurality of auxiliary pixels are assigned to one pixel of a secret image. This means that the pixels of the tally image become substantially finer, and as the number of auxiliary pixels increases, there is a problem that it becomes difficult to match the tally with human hands. It is not necessary to disperse to the auxiliary pixels, and it has an effect of not causing the problem that the pixels of the tally image become small.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An image generation system according to the present invention will be described in detail below with reference to FIG.
[0024]
As shown in FIG. 1, first, a secret image 1 to be distributed and stored is prepared. The secret image 1 is a monochrome binary image. For example, a secret image 1 on which characters “PATTERN” are drawn is prepared.
[0025]
The secret image 1 is converted into two or more tally images based on pixel value information (command for setting pixel values; command data for setting and setting set pixel values of the same color component) called color set data, For example, as shown in FIG. 1, the image is divided into two tally images 2 and 3.
[0026]
Each of the plurality of tally images, that is, the two tally images 2 and 3 shown in FIG. 1, are interpreted as a predetermined meaningful pattern as seen by the human eye like the characters “PATTERN” of the secret image 1. Each image is not a recognizable image, but is set to a random color image, and its meaning cannot be read (recognized), and a single tally image is examined in detail using a scanner or the like. However, information about secret images is not known.
[0027]
Therefore, even if only one tally image is examined, it is impossible to analogize the secret image 1, and as long as the tally images are stored separately, the secret image can be known. There is no sex.
[0028]
Each of the two tally images is generally printed and stored on a sheet, but at least one or both of them is printed and stored on a transparent sheet. On the other hand, the secret image 1 is reproduced by superimposing the tally images printed on the sheet.
[0029]
When the tally images, for example, the tally images 1 and 2 shown in FIG. 1, are superimposed on each other, the secret image, that is, the characters “PATTERN” of the secret image 1 shown in the figure are reproduced so that the secret image can be confirmed. become.
[0030]
A physical configuration on the computer of the image generation system according to the embodiment of the present invention will be described with reference to FIG.
[0031]
This image generation system includes a CPU 101, an image memory 102, an image input unit 103, data generation and recording of tally images 2 and 3 from the input of at least the secret image 1, and superimposition of the tally image data and reproduction image 4 as necessary. The program memory 104 and the image recording unit 105 for controlling the process until the image forming and reproduction image confirmation operation) are all connected by a bus 106, and the CPU 101, the image memory 102, the image input unit 103, The image processing unit 107 is configured by the program memory 104.
[0032]
The operation of the image generation system will be briefly described. First, the secret image 1 is written in a predetermined area of the image memory 102 through the image input unit 103.
[0033]
Based on the algorithm shown below, a predetermined secret image (for example, secret image 1 called “PATTERN”) is subjected to arithmetic processing to create two or more tally images (for example, tally images 2, 3). Then, the tally image is recorded on a recording medium by the image recording unit 105 or is recorded in the form of a printed matter, and the recording information of the tally image is output as a tally.
[0034]
A series of these processes is performed by the CPU 101 based on a program stored in the program memory 104. A dedicated device may be used for the processing, but a general-purpose computer such as a personal computer may be used. In this case, the image memory 102 and the program memory 104 generally use the same memory in divided areas.
[0035]
A flowchart of these processing operations is shown in FIG. First, a secret image to be safely distributed and stored is input through the image input unit 103. Next, based on information called color set data (command data for specifying and setting set pixel values of the same color component), the secret image is stored. It is dispersed into color tally images and recorded and stored as a recording medium in the image recording unit 105 or recorded and stored as a printed matter. Then, the saved tally image is output as an image by printing or the like to create a tally.
[0036]
Next, the notation of the image and the principle of the present invention will be described with reference to FIG. 4. First, the monochrome binary image shown in FIG. 4A and the color image shown in FIG. It is written in.
[0037]
A monochrome binary image as a line drawing monochrome image or a continuous (continuous tone) monochrome image shown in FIG. 4A is an image in which each pixel (each subdivided small square) is white or black, and depends on the line drawing. Either a digital signal or an analog signal is used as a black and white image processing signal, the black pixel value is designated by K = 0 (or 1), and the white pixel value is designated by W = 1 (or 0). Is an image having a pixel value K of 0 and white pixels having a pixel value W of 1.
[0038]
On the other hand, the color image shown in FIG. 4B is designated by pixel values of three color components (three primary colors) of R (red color), G (green color), and B (blue color) possessed by each pixel. The
[0039]
Here, the pixel value of each color component takes a real value (decimal system) of 0 to 1, and the pixel values of three color components (R, G, B) of a certain pixel are (R, G , B) = (1,1,1) is a white pixel, (R, G, B) = (0,0,0) is a black pixel, and each color component has a pixel value of 0 to 1. In the range of (decimal system), when an appropriate real value of (R, G, B) = (r, g, b) is taken, it becomes an appropriate color tone pixel (or an appropriate color tone halftone pixel).
[0040]
In the present invention, description has been made using R, G, and B as the color image format. However, in the present invention, for example, Y (yellow color), M (magenta) is not limited to this format. The color image of each pixel may be specified by the pixel values of the four color components (colors), C (cyan), and K (black) (printing three primary colors + black). Besides, the pixel values of the three color components (three primary colors) of R (red color), G (green color), and B (blue color) possessed by each pixel are designated by the real values of 0 to 1 above. For example, the pixel value of each color component may take a binary number, and may be designated as a digital signal using 1 to 8 bits (1/8 byte to 1 byte); 2 to 256 types of numerical values. .
[0041]
Next, the visual recognition ability in the human uniform region, which is the principle of the tally image in the present invention, will be described.
[0042]
In a color image as shown in FIG. 4 (for example, reproduced image 4 in the present invention), a human can naturally recognize that the characters “PATTERN” are written at the center of the image. .
[0043]
This is because the peripheral portion of the color image is a “random region” Ra having random pixel values, whereas the character portion “PATTERN” is a “uniform region” Ua having the same gray pixel value. It is.
[0044]
Humans have the ability to naturally perceive and recognize such uniform areas, and the present invention uses this human ability. That is, when the tally images are overlaid, the black part of the characters “PATTERN” in the secret image becomes a uniform area having pixel values of the same color, and the white part becomes a random area having random pixel values. If a tally image is generated, at the time of reproduction, a human can visually recognize the character “PATTERN” in the secret image.
[0045]
Note that when the tally images as color images are overlapped with each other, the color changes as shown in FIG.
[0046]
FIG. 6 represents a change in color when tally images are superimposed on each other by pixel values. For example, the pixel values of R, G, and B of one pixel on one tally image are ( R, G, B) = (r0, g0, b0), and R, G, B pixel values of the pixel at a position corresponding to (matching) the pixel on the one tally image on the other tally image However, when (R, G, B) = (r1, g1, b1), the color that appears when the tally images are superimposed on each other is (R, G, B) = (r0 * r1, g0 *). The pixel value is represented by multiplication of g1, b0 * b1).
[0047]
For example, a pixel having a pixel value of (R, G, B) = (0.4, 0.8, 0.6) and (R, G, B) = (0.6, 0.3, 0.4) When the pixels with the pixel values of “(R, G, B)” are overlaid, the color of the pixel value expressed by (R, G, B) = (0.24, 0.24, 0.24) will appear.
[0048]
Next, as a specific example of the embodiment of the present invention, a case where the secret image is a monochrome binary image and the secret image is divided into two tally images will be described based on the flowchart of FIG. The present invention is not limited to this specific example.
[0049]
[First step; input of secret image]
First, the secret image 1 is input as digital data.
When the input image (original image) of the secret image 1 is a hard copy or a silver halide photograph, it is read by a digital scanner and input as digital data. If the input image is already digital data, it is converted into an appropriate image format and input. For example, in one embodiment, the secret image 1 is a black and white binary image. If the secret image 1 is a grayscale image (continuous tone image) or a color image, a black and white binary is obtained by performing conversion processing on the image. Convert to an image and input.
[0050]
[Second Step; Generation of Tally Image]
Next, the inputted secret image 1 (black and white binary image) is divided into color tally images 2 and 3 in which two sets are made into one set (one set) based on the color set data.
[0051]
This color set data is a color in which a combination of pixel values of two types of color components for determining the color of each of the two tally images 2 and 3 according to the pixel value of the secret image 1 is set as one set. This indicates the type of set, and is composed of two or more types of color sets. Note that the color components used for each type of color set all use the same color component, and which color component (R, G, B) to use is created. It is determined arbitrarily by the person in advance.
[0052]
Of the two tally images 2 and 3 formed as a color image from the secret image 1, the color set data is for the pixels corresponding to the black pixels and white pixels of the secret image 1 in each pixel of one tally image 2. In other words, the same pixel value of one color component or two color components or all three color components among the RGB color components is assigned, and pixels corresponding to the black pixels and white pixels of the secret image 1 in each pixel of the other tally image 3 Is set so that pixel values of one color component, two color components, or all three color components of the RGB color components are allocated and pixel values different from the pixels of the tally image 2 are allocated.
[0053]
Thus, based on the color set data, the pixel value of the color component assigned to the pixel of the one tally image 2 and the pixel value of the same color component assigned to the pixel of the other tally image 3 are: Although the pixel values are different from each other, the product (logical product) of both the pixel values is set to be the same value.
[0054]
Based on one color set (set color component and its pixel value) that is randomly selected (selected using a random number described later) from color set data composed of two or more types of color sets. By assigning pixel values of color components to the tally image 2 and the tally image 3, color tally images 2 and 3 are formed in which two sheets are one set (one set).
[0055]
Specific examples of the color set data are shown in FIGS. 7A to 7B. In the example of FIG. 7, for example, as shown in FIG. Three sets (set 0, set 1, set 2) of color information (pixel values) are prepared, and as shown in FIG. Color information (pixel values) of set 0, set 1, and set 2) is prepared.
[0056]
For example, in the color information of the three sets of black pixels (set 0, set 1, and set 2) shown in FIG. 7A, in the set 0, one of the two tally images 2 and 3 that are color images is displayed. One of the RGB components of the pixel value of a pixel of the tally image 2 is “0.98”, and one of the RGB components of the pixel value of the pixel corresponding to the pixel of the other tally image 3 is “0.5”. Indicates that it is set. Note that the R, G, and B components of the pixel values corresponding to each other of the both tally images may be the same color component or set as different color components.
[0057]
In this case, when the color components of the corresponding pixels of both tally images are set as the same color component, the reproduced image 4 obtained by superimposing the two tally images on each other is shown in FIG. As shown, the pixel value of the same color component of the corresponding pixel is “0.98 * 0.5 = 0.49”.
[0058]
As shown in FIG. 7A, in any one of the set 0, set 1, and set 2 of the black pixel values of both tally images 2 and 3, the pixel values of the reproduced image 4 are all the same “ 0.49 ", as shown in FIG. 7B, in any of the set 0, set 1 and set 2 of the white pixel values of both tally images 2 and 3, Random random values such as “0.69” and “0.25” are taken.
[0059]
This is because, for the black pixel portion of the secret image 1, all the portions of the reproduced image 4 corresponding to the black pixel portion have the same color (for example, the same color with the above-described pixel value “0.49”). For the white pixel portion of the image 1, this means that the portion of the reproduced image 4 corresponding to the white pixel portion has a random color.
[0060]
Further, as shown in FIGS. 7A to 7B, the tally images 2 and 3 in the black pixel portion of the secret image 1 and the tally images 2 and 3 in the white pixel portion of the secret image 1 are the same. There are the same number of pixel values of the same value of the color component. For example, in this example, there are three types of values of pixel value = 0.98, 0.7, and 0.5. This is because even if only one of the tally images 2 and 3 is analyzed, the secret image 1 cannot be judged as a set of black pixel portions and white pixel portions with only one of the tally images, and the secret is safely distributed. It means that
[0061]
That is, the black pixel portion of the tally image 2 shown in FIG. 7A and the white pixel portion of the same tally image 2 shown in FIG. 7B show the same pixel value of the same color component. This is because the black pixel portion of the tally image 3 shown in FIG. 7A and the white pixel portion of the tally image 3 shown in FIG. 7B also show the same pixel value of the same color component.
[0062]
The actual generation of the tally images 2 and 3 is performed by calculation processing of input instruction data under computer control.
[0063]
Color set (set color component and its pixel value) selected at random using random numbers from color set data (see FIGS. 7A to 7B) composed of two or more types of color sets Is assigned to the black and white pixels of the secret image 1 which is a black and white binary image, and the following processing is repeated.
[0064]
In the case of the color set data shown in FIGS. 7A to 7B, since there are three sets of set 0, set 1, and set 2, random numbers are uniformly generated in the range of 0 to 2, and the generated random number values. Then, the color component of the pixel value of one pixel of the tally images 2 and 3 is determined according to the pixel value (black pixel portion and white pixel portion) of the pixel of the secret image 1. The creator arbitrarily adopts, for example, an R (red) component in advance among the R, G, and B color components as the color components of the pixels of the tally images 2 and 3 in advance.
[0065]
{Circle around (1)} First, the pixel portion where the pixels of the secret image 1 are black is divided into tally images 2 and 3. In this case, random numbers are generated using computer random number generation means in accordance with the number of sets of color set data input to the computer, and when the generated random number is 0, the input color set data shown in FIG. , The pixel value of the R component of one pixel of one tally image 2 corresponding to one pixel of the secret image 1 corresponding to one black pixel is “0.98”, and one pixel of the other tally image 3 corresponding thereto The pixel value of the R component is determined to be “0.5”.
[0066]
(2) Next, the pixel portion where the pixel of the secret image 1 is white is divided into tally images 2 and 3. In this case, similarly, a random number is generated using computer random number generation means, and when the generated random number is 0, the pixel of the secret image 1 is white based on the input color set data shown in FIG. The pixel value of the R component of one pixel of one tally image 2 corresponding to one pixel is “0.98”, and the pixel value of the R component of one pixel of the other tally image 3 corresponding to “0. 7 ".
[0067]
By repeating the above data processing (1) and (2) for every pixel of the secret image 1, the color and pixel of each pixel constituting the tally images 2 and 3 are determined, and the color set data is obtained. The tally images 2 and 3 as color images based thereon are generated and recorded in the image recording unit.
[0068]
[Third Step: Output Tally Image]
Finally, the image data of the generated tally images 2 and 3 recorded in the image recording unit is output by the data output unit (color monitor, color laser printer (plateless printing machine), plate printing machine, plotter). Output as tally image.
[0069]
The output is basically performed in the form of printing on a transparent sheet by a printer. Printing is performed using a commercially available laser printer or offset printing machine. In general, in printing, it is necessary to convert R, G, B three-color component data into Y, M, C, K print color data and convert it into ink amounts. It has been widely known as a color conversion technique. Note that the data generation of the tally images 2 and 3 can be processed from the beginning on a Y, M, C, and K basis, and in this case, the conversion process can be omitted.
[0070]
In the image generation system and method of the present invention described above, a series of generation processing is realized by software on a computer, but can also be realized by hardware as a dedicated generation processing device.
[0071]
FIG. 8 is a block diagram of the dedicated generation processing apparatus, in which an image memory 201 for storing the secret image 1, a random number generation unit 202 for generating a random number, a tally generation unit 203 for generating a tally image, and a tally image ( An image generating apparatus (system) is configured in which image recording means 204 is recorded which is recorded in the form of a printed material or is recorded as electronic data (data recording material) on a recording medium.
[0072]
In the processing by hardware, first, the secret image 1 is converted into digital data and stored in the image memory 201. A random number is generated in the random number generation means 202, and the tally images 2 and 3 are generated by the tally generation means 203 based on the image data of the secret image 1 input from the image memory 201 and the random number generated from the random number generation means 202. . Then, the image recording means 204 converts the tally image data of the R, G, B system into the tally image data of the Y, M, C, K system and, if necessary, once a recording medium (floppy disk, hard disk). After being stored on a compact disc, an optical disc, a magneto-optical disc, a magnetic tape, etc., a tally is output by being recorded in a hard copy form on an output medium (a transparent sheet such as a plastic film).
[0073]
As described above, the above-described image generation processing can be easily realized by hardware. When hardware is used, it is possible to perform processing at high speed, and it is particularly effective when it is necessary to generate many types of tally or when it is necessary to duplicate a large number of one type of tally.
[0074]
[Fourth Step: Formation of Reproduced Image by Superimposing Tally Images]
In the method of forming the tally images 2 and 3 generated as described above as a reproduced image, the generated tally images 2 and 3 are output as hard copies (for example, printed matter) on a sheet, and the output tally image is output. There is a method of forming a reproduced image 4 (an image corresponding to the secret image 1) by superimposing 2 and 3 in a hard copy state, automatically or mechanically by a superimposing apparatus or the like, or by manual operation. is there.
[0075]
In addition, the generated tally images 2 and 3 are superposed in the state of electronic data on the computer via electronic data superposition processing means provided on the computer, and the electronic data corresponding to the reproduced image 4 is obtained. A method of forming reproduced image data (image data corresponding to the secret image 1) can be employed.
[0076]
A tally image reproducing apparatus that reproduces the reproduced image 4 corresponding to the secret image 1 by superimposing the generated tally images 2 and 3 in a hard copy (printed material) state will be specifically described.
[0077]
FIG. 9 is a perspective view showing an example of the configuration of a playback device, which is a fixing device 20 (fixed frame) for loading and fixing two tallys 2 and 3 (tally images; hard copy) to the playback device. . Thereby, tallys are fixed to a predetermined positional relationship. For example, at least two positions of the margin portions of the two tally images 2 and 3, a registration mark capable of positioning and aligning the relative positions of both images is formed, and the registration marks are overlapped with each other. The tallys are fixed in a predetermined positional relationship.
[0078]
If an image corresponding to the secret image 1 is observed from the reproduced image 4 formed by the two overlapping tally images 2 and 3 fixed, it is recognized that the tally image is a true combination. If no image corresponding to the secret image 1 is observed, it is recognized that the tally image is not a true combination.
[0079]
In the case where the two tally images 2 and 3 which are fixed and overlapped with each other have a transparent sheet as a base sheet, a light source L such as a light bulb is disposed below the fixing device 20 loaded in the playback device. Thus, it is possible to make the reproduced image 4 clearer. Note that the playback device is not limited to such a configuration, and may have any structure as long as the tally can be fixed in the correct positional relationship.
[0080]
Further, as a method for facilitating the reproduction, a registration mark 5 capable of positioning and aligning the relative positions of both images is formed in each margin portion of the two tally images 2 and 3 as shown in FIG. The tally marks are easily fixed in a predetermined positional relationship by overlapping the register marks 5 with each other. Alternatively, an adhesive material having a relatively weak adhesive force may be applied to or pasted on the inner surface of the sheet 10 so that the position does not easily shift after the sheets are once overlapped.
[0081]
In the case of reproduced image data formed by superimposing the generated tally images 2 and 3 in the state of electronic data, the reproduced image data is reproduced via an image data reading unit or a data collating unit on a computer. The secret image 1 corresponding to 4 can be read or verified.
[0082]
Thus, when the secret image 1 is read from the reproduced image data, it is authenticated that the tally images 2 and 3 are images of a genuine combination. On the other hand, when the secret image 1 is not read, the tally It is authenticated that the images 2 and 3 are not authentic images.
[0083]
In the present embodiment, the example in which the secret image 1 is divided into the two tally images 2 and 3 has been described. However, by changing the color set data to three or more color set data, the secret image 1 is converted into three or more tally images. It is also possible to divide. However, if a large number of images are superimposed, the reproduced image may become dark and difficult to see, and the number of images to be superimposed is limited.
[0084]
【The invention's effect】
According to the present invention, a secret image, which has been impossible in the past, is divided into two or more color tally images, and these are dispersed and stored to ensure confidentiality of the secret image and the secret data contained in the image. Compared to black and white tally images, it is possible to express a very rich tally, which not only looks good, but also enhances the enjoyment of entertainment, and also makes it copy by coloring It has the effect of making it difficult to use a copy machine, etc., and enhancing the effect of preventing forgery.
[0085]
Further, there is no need for an operation such as assigning a plurality of auxiliary pixels to one pixel of the secret image as in the conventional method, and the effective area of each pixel of the tally image due to the auxiliary pixel assignment becomes smaller. This is effective for refining the tally image.
[Brief description of the drawings]
FIG. 1 is a block diagram for explaining the definition of a secret image, a tally image, and a reproduction image in an image generation system of the present invention and a recorded product thereof and an outline of the relationship.
FIG. 2 is a block diagram for explaining an example of an image data processing operation in the image generation system of the present invention.
FIG. 3 is a flowchart for explaining an example of the processing operation order of image data in the image generation system of the present invention.
4A is a plan view for explaining pixels arranged in a monochrome binary image of a secret image, a tally image, and a reproduction image in the image generation system of the present invention, and FIG. 4B is a secret image and a tally image in the system. FIG. 6 is a plan view for explaining pixels arranged in a color image of a reproduced image.
FIG. 5 is a plan view for explaining a reproduced image in the image generation system of the present invention.
FIG. 6 is an explanatory diagram showing numerical values of color components and pixel values of each pixel of a reproduced image obtained by superimposing two tally images in the image generation system of the present invention.
FIG. 7A is a data table of color set data used when converting a black pixel portion of a secret image used in the image generation system of the present invention into a tally image, and a pixel table of the set (set) of pixel values. Explanatory drawing which shows an example, (b) is the color set data used when converting the white pixel part of the secret image used in the image generation system of this invention into a tally image, and the data regarding the pixel value of the set (set) Explanatory drawing which shows an example of a table.
FIG. 8 is a block diagram for explaining another example of the image data processing operation in the image generation system of the present invention.
FIG. 9 is a schematic diagram for explaining an example of a fixing device used for overlaying and fixing and reproducing a hard copy on which a tally image is formed in the image generation system of the present invention.
FIG. 10 is a plan view illustrating pixels of a tally image generated by the image generation system of the present invention and superposition of the images.
[Explanation of symbols]
1 ... Secret image 2 ... Tally image 3 ... Tally image 4 ... Reproduced image 5 ... Mark
10 ... sheet 20 ... fixing device
101 ... Central processing control unit 102 ... Image memory 103 ... Image input unit
104 ... Program memory 105 ... Image recording unit 106 ... Bus
107: Image processing unit
201 ... Image memory 202 ... Random number generator 203 ... Tally generator
204: Image recording unit
L ... Light source Ua ... Uniform area Ra ... Random area

Claims (8)

An image data input unit for inputting secret image data;
One set (one set of two or more pixel values corresponding to the number of tally in one set of tally registered in the color set data table stored in the external or internal memory and the secret image data input from the image data input unit on the basis of each corresponding to a black pixel portion and the white pixel portions of the secret image data in the color set data to), it generates pixel data of two or more plurality of tally images for each pixel of the secret image data, the secret image A central processing control unit comprising a program memory for controlling the process from the input of the secret image for generating the tally image data of the random image that cannot be read by the secret image of the data to the data generation and recording of the tally images 2 and 3;
An image data memory unit for storing the generated tally image data ,
Image generation system characterized by comprising a. 2. The image generation system according to claim 1, wherein each of the color set data in the color set data table includes two or more combinations of color sets, and one type from among the color sets for each pixel of the secret image data. A tally image data is generated by selecting two color sets and generating pixel data of two or more tally images. 2. The image generation system according to claim 1, wherein each of the color set data in the color set data table includes two or more combinations of color sets, and one type from among the color sets for each pixel of the secret image data. An image generation system characterized in that a tally image data is generated by selecting a color set using a random number and generating pixel data of two or more tally images. An image memory unit for storing secret image data;
The secret image data inputted from the image memory unit and the secret having two or more pixel values corresponding to the number of tally in one set of tally registered in the color set data table stored in the external or internal memory as one set The tally image data of a random image that is more than one for each pixel of the secret image data and the secret image of the secret image data cannot be read alone based on the color set data of the black pixel portion and the white pixel portion of the image data. A tally generator to generate,
An image data recording unit for recording tally image data generated by the tally generation unit;
Image generation system characterized by comprising a. 5. The image generation system according to claim 4, wherein each of the color set data in the color set data table includes two or more combinations of color sets, and one type out of the color sets for each pixel of the secret image data. A tally image data is generated by selecting two color sets and generating pixel data of two or more tally images. 5. The image generation system according to claim 4, wherein each of the color set data in the color set data table includes two or more combinations of color sets, and one type out of the color sets for each pixel of the secret image data. An image generation system characterized by generating tally image data by selecting two or more tally image pixel data by selecting a color set based on a random number value generated from a random number generator.   7. Two or more tally images each based on two or more tally image data generated based on the secret image data and the color set data by the image generation system according to claim 1. An image recorded matter, wherein the recorded matter is output and recorded on each of the sheets using a hard copy output means.   7. Two or more tally image data generated based on the secret image data and color set data by the image generation system according to claim 1 is recorded as electronic data. An image recording medium characterized by the above.

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