JP2006270197A - Woven pattern print density adjustment support program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a woven pattern print density adjustment support program for maximizing contrast after copying a pattern. <P>SOLUTION: The program has a density adjustment function. THe density adjustment function includes a first step for displacing dot density in a latent image for density adjustment and dot density in a background section by each fixed width, generating a patch image in which a latent image and the background are drawn by the combination of their values, and arranging the patch image in a matrix shape at a printing region for printing a test chart; a second step for allowing a user to input a plurality of patch image groups in which the contract of the latent image section and the background section is within a tolerance from the test chart; a third step for allowing the user to input the plurality of patch image groups in which the contrast of the latent image section and the background section is within a tolerance from a test patch in a test charge duplication obtained by copying the test charge duplication; and a fourth step for determining one optimum patch image from the plurality of patch image groups in two series input in the second/third steps. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to prevention of counterfeiting of printed matter of an electronic document, and particularly relates to a tint block print density adjustment support program.

  Conventionally, for the purpose of prohibiting or suppressing copying of forms and resident cards, these contents have been printed on a specially-printed paper called anti-counterfeit paper. The anti-counterfeit paper is paper that is difficult for humans to see in the original, but when a copy machine or the like is used for copying, a predetermined character such as “prohibited copy” is raised. The forgery-preventing paper has a problem that the cost is higher than that of normal paper, and only characters set at the time of printing (when the forgery-preventing paper is produced) can be raised.

  On the other hand, as various contents are digitized, contents such as forms and resident's cards are also digitized. However, the digitization of content such as forms and resident's cards is still in a transitional state, and it is common to use content created using a computer on paper using a printer or the like.

  In addition to such a situation, due to a dramatic improvement in printer performance in recent years, a technique that uses a computer and a printer to achieve the same effect as a conventional anti-counterfeit paper has attracted attention. This is a technique in which when a content created using a computer is output using a printer, a pattern called a background pattern is superimposed on the background of the content and output. The copy-forgery-inhibited pattern looks like a simple pattern in the original (the content immediately after being output by the printer), but when copied, a predetermined character (latent image) is lifted, and has the same effect as the anti-counterfeit paper.

  When using a computer to output a copy-forgery-inhibited pattern, it is natural that it can be output using ordinary plain paper, which is advantageous in terms of cost compared to anti-counterfeit paper. Furthermore, by generating a copy-forgery-inhibited pattern when content is output, in addition to static character strings such as “prohibited copying”, dynamic character strings such as user names and output dates can be highlighted. There is also an advantage.

  In such a copy-forgery-inhibited pattern print, the latent image portion of the copy-forgery-inhibited pattern is composed of dots larger than the resolution that the copier can recognize, and the background portion is composed of dots smaller than the resolution that the copier can recognize. It is a big feature.

  In order to achieve the purpose of preventing forgery, the latent image portion and background portion of the printed tint block must be printed with low contrast and the copy copy of the tint block must be printed so that the contrast between the latent image portion and the background portion is large. Don't be. Therefore, the dot density of each portion is designed so that the dot area (area density) per print area is the same in the latent image portion and the background portion.

  However, in actual printing, there are differences in the degree of toner adhesion between large dots and small dots due to factors such as printer model characteristics, individual printer characteristics, environmental conditions such as temperature and humidity, and surface characteristics of printing paper. This causes a problem that the density of the latent image portion and the background portion does not look the same. At the same time, there is a problem that the density of the latent image portion and the background portion do not look the same due to the color of the printing paper.

  In order to solve these problems, the conventional technology has provided means for adjusting the dot density of the latent image portion and the background portion in the tint block printing software. The means is as follows. First, a basic patch image is created in which a suitable character is drawn as a latent image with large dots, and the background is drawn uniformly with small dots so that the background is dropped after copying. Then, in the vertical direction, the density of large dots is changed by a certain width, and in the horizontal direction, the density of small dots is changed by another width, arranged in a matrix, and printed as a test chart (FIG. 1). At this time, the respective density values are printed on the outside of the patch matrix so that a combination of the density values of the large dots and the small dots of each chart can be obtained immediately. This printed matter is visually confirmed by a human to determine one with the smallest contrast between the latent image portion and the background portion. Next, in the density adjustment dialog (FIG. 2) of the tint block printing software, the screen portion representing the previously determined patch is clicked for selection and input. Providing such a copy-forgery-inhibited pattern print density adjusting means makes it possible to compensate for the minimalness of contrast, which has not been ensured due to the factors described above.

  Further, although not directly related to tint block printing, the following printing system (see Patent Document 1) has been proposed as a conventional technique for adjusting the printing density of a printer.

Each element has a function that allows each element to communicate with each other in a printing system including a plurality of printers, a plurality of PCs, and a printer server. Then, density adjustment between printers is realized by the following three steps. First, the printer server acquires and records density correction data from each printer, and then the PC refers to the latest correction data to create and store a gradation correction table for each printer, and finally from each printer. For each correction request, the density correction table stored in the printer server is updated.
JP 11-161455 A

  As described in the prior art, the conventional tint block density adjustment system displaces the dot density of the latent image portion and the dot density of the background portion with a certain width for density adjustment, and by combining these values. A patch image in which the latent image and the background are drawn is generated, the patch image is arranged in a matrix in the print area, and a test chart (FIG. 1) is printed. From the test chart, the latent image portion and the background portion are printed. Only means (FIG. 2) for allowing the user to input only one patch image having the minimum contrast is provided. For this reason, there is no means for adjusting whether or not the copy-forgery-inhibited pattern appears in the copy obtained by copying the copy-forgery-inhibited pattern print, that is, whether the contrast after copying is sufficient.

  The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a tint block print density adjustment support program capable of maximizing the contrast after copying a tint block.

  In order to solve this problem, means for inputting information relating to the contrast after copying is provided in the tint block print density adjustment system. However, this causes a new problem that the ideal patch image before and after copying may not match. Therefore, a plurality of acceptable patch images can be selected for each input of the printed test chart and the copied test chart (FIGS. 3 and 4). Then, by automatically selecting one optimum patch image from before and after copying, and adjusting the density of the tint block printing with a set of dot density values represented by the patch image, the contrast of the printed matter can be reduced. In addition to being small, it is possible to perform copy-forgery-inhibited pattern printing which ensures that the copy has a high contrast.

  That is, the present invention is a copy-forgery-inhibited pattern print density adjustment support program, in which the dot density of the latent image part and the dot density of the background part are displaced by a certain width for density adjustment, and the latent image and A first step of generating a patch image on which a background is drawn, arranging the patch images in a matrix in a print area and printing a test chart, and a contrast between the latent image portion and the background portion in the test chart is The second step for allowing the user to input a plurality of patch image groups within the allowable range, and the contrast between the latent image portion and the background portion from the test patch in the test chart copy obtained by copying the test chart printed material is within the allowable range. A third step for allowing the user to input a plurality of patch image groups, and a plurality of two series input in the second step and the third step A copy-forgery-inhibited pattern print density adjusting support program characterized by having a density adjustment function comprising a fourth step of one determining the optimum patch images from the patch image group.

According to the present invention,
・ The print density can be adjusted in consideration of the contrast after copying in background pattern printing.

  -It is possible to reduce labor and time for selecting an optimum density pattern for tint block printing.

  -Even if the number of target copiers increases, a density adjustment workflow with less confusion can be provided.

  One embodiment of the present invention is shown in FIGS.

  First, the configuration of the tint block printing system that adjusts the magnitude of contrast after copying will be described. Please refer to FIG. A content printing unit 701 is a general application, and is a part that performs printing based on the content of the application. The printer driver 702 is a part that issues a print command to the printer by replacing it with a language that the printer can interpret in accordance with a print command from the content print unit 701 or the copy-forgery-inhibited pattern print unit 703. A printer 710 receives a print command and performs printing by physical means such as attaching toner to print paper in accordance with the command. A copy-forgery-inhibited pattern print unit 703 performs copy-forgery-inhibited pattern printing from graphic information (font, size, position, angle, color, repetition interval) and density information (dot density of the latent image portion and background portion) held by the copy-forgery-inhibited pattern setting unit 704. Part. A copy-forgery-inhibited pattern setting unit 704 is a part that determines and holds the values of the graphic information and density information by user input, input from an application, or automatic calculation. A copy-forgery-inhibited pattern setting unit 705 is a part for setting and holding the graphic information. A copy-forgery-inhibited pattern density setting unit 706 is a part for setting and holding the density information, and is a central part of the present invention. According to the prior art, this part is composed only of a test printing part and a user input part, and the user visually determines the result of the test printing by the test printing part and determines one value as the user input part. It was something to be entered. In this embodiment, the function of the user input unit 707 is expanded so that a plurality of patch images can be selected by a plurality of times of input and each time of input. From these inputs, the automatic density adjustment unit 708 selects an optimum set of dot density values, and stores the selected set of dot density values in the external storage device 711. 709 is a test pattern in which a patch image is generated by displacing the dot density values of the latent image portion and the background portion at regular intervals around the set of dot density values stored in the external storage device 711 and arranged in a matrix form Is a test printing section for printing

  Next, the overall flow of tint block print density adjustment will be described with reference to FIG. When the copy-forgery-inhibited pattern printing density adjustment is started, first, a process for calculating test printing parameters is performed. Subsequently, a test chart is printed based on the calculation result. Next, an input dialog is displayed in order to input the result visually determined by the user who has obtained the printed test chart. Next, automatic density calculation processing for determining an optimum density based on the result input by the user is performed. If a set of optimum dot density values can be calculated without any problem, the values are stored in the external storage, and the tint block print density adjustment process is terminated. If an exception occurs and an appropriate value cannot be calculated, the process returns to the test print parameter calculation process again.

  Next, a parameter calculation process for test printing will be described with reference to FIG. When the test print parameter calculation process is started, it is first determined whether or not this is the first test print. If this is the first time, proceed as follows. First, a previously stored set of dot density values (X0, Y0) is acquired from the external storage device. Next, the latent image partial dot density displacement dX0 set at the time of shipment is acquired. Next, the background portion dot density displacement dY0 set at the time of shipment is acquired. Next, the latent image portion dot density is displaced by dX0 and the background portion dot density by dY0 around the set (X0, Y0) of the dot density values stored last time from the external storage device, and the two-dimensional array (FIG. 10). Reference). If test printing is not the first time, the following processing is performed. First, the dot density value set range {(X1, Y1), (X2, Y2)} calculated by the automatic density calculation unit is acquired. Next, the dot density range (X2−X1) of the latent image portion is divided by the number NX of patch images in the horizontal direction on the test printing paper to obtain the dot density displacement dX1 of the latent image portion. Next, the dot density range (Y2−Y1) of the background portion is divided by the number NY of patch images in the horizontal direction on the test printing paper to obtain the dot density displacement dY1 of the background portion. Next, the starting point of the dot density range (X1, Y1) is used as it is, the latent image portion dot density is displaced by dX1, the background dot density is displaced by dY1, and a two-dimensional array (see FIG. 11) is obtained. Generate. In the test print parameter calculation process, a two-dimensional array of dot density value sets is generated as described above. In the test printing process, a patch image is generated for each element of the two-dimensional array, arranged on the print area in the same arrangement as the two-dimensional array, and a test chart (see FIG. 1) is printed.

  Next, an outline of the flow of user input processing will be described with reference to FIG. When the test printing is completed, the user obtains a printed test chart. The copy-forgery-inhibited pattern printing density adjustment program then displays a density adjustment dialog before copying (FIG. 3) to prepare for user input. The user views the test chart printout and inputs the result. When the input is completed, a dialog asking whether to continue the input is displayed. If the user selects NO, the user input process is terminated. If the user selects YES, the process proceeds to input processing for a copy. In this case as well, the density adjustment dialog after copying (FIG. 4) is displayed in preparation for the user's input in the same manner as the input process for the printed matter. The user sees a copy of the test chart printed matter copied by the copying machine and inputs the result. When the input is completed, the process returns to the process of displaying a dialog asking whether to continue the input, and is repeated. In this way, the copy can be repeatedly evaluated. The flow of the copy-forgery-inhibited pattern latent image differs depending on the type of copying machine, so it is possible to input the results of copying with multiple copying machines. This is to enable highly accurate copy-forgery-inhibited pattern printing.

  Next, the detailed flow part of the user input process will be described with reference to FIG. Since the processing is the same for both the printed material input processing and the copied material input processing, only the printed material input processing will be described. When the user input process is started, first, a variable P representing the priority of the patch image is initialized to zero. In addition, a two-dimensional array (see FIG. 14) having the same number of elements for each dimension as the patch image and the number of vertical and horizontal is prepared on the main memory, and each element is initialized with a sufficiently large number Pmax (999). Next, a density adjustment dialog as shown in FIG. 3 or 4 is displayed. Then wait for 20ms without doing anything. Next, check whether there is user input from the keyboard or mouse. If there is no input, the 20 ms waiting process is repeated. If there is a user input, the subsequent processing is branched depending on the content of the input.

  When the user input is selection of a specific patch image, the selected patch image on the dialog is surrounded by a red line, and the value P is drawn in the upper right part of the patch image. Then, a dot density value set corresponding to the patch image is acquired, and the value of the variable P representing the priority is substituted into an element in which the values of the vertical axis and the horizontal axis of the two-dimensional array are equal to the dot density value set. Increase the value by one. Then, the waiting process of 20 ms is repeated.

  If the user input is a “next” or “done” button press, the two-dimensional array is stored in the memory, and the detailed process of user input ends.

  When the user input is a “return” or “cancel” button, the two-dimensional array is stored in the memory, and the detailed process of the user input is terminated.

  If the user input does not correspond to any of the above, it is regarded as an invalid input and the waiting process of 20 ms is repeated.

Next, the flow of automatic density calculation will be described with reference to FIG. When the automatic concentration calculation process is started, first, all the two-dimensional arrays generated by the dialog input process are summed (see FIG. 16). Next, each element of the summed two-dimensional array is compared with the initialization constant Nmax of the array element. Then, it is determined whether one or more elements smaller than Nmax exist. If there is an element smaller than Nmax, the element having the smallest value is calculated so as to be smaller than Nmax, and the dot density value set corresponding to the element having the smallest value is stored as the result of the automatic density calculation. Then, the automatic density calculation process is terminated. If there is no element smaller than Nmax, the range of dot density value groups necessary for printing the test chart again is calculated as follows. First, a variable R representing a range is initialized as an empty range. Next, a loop for extracting any two two-dimensional arrays from all the two-dimensional arrays is started. This loop is completed when all two two-dimensional array combinations have been extracted. The following processing is performed in the loop. First, for each of the two extracted two-dimensional arrays A and B, elements (a1, a2,...) And (b1, b2,...) Smaller than Nmax are extracted. Then find i = i0, j = j0, where the distance between a _i and b _j is minimum. Then, a range Rn having a _i0 and b _j0 as diagonal lines is calculated. Next, let R be a new range obtained by merging R and Rn. This is repeated as a loop process. The obtained R is stored as a result of the child concentration calculation, and the automatic concentration calculation processing is terminated.

Diagram showing printed test chart Dialog to select minimum contrast pattern Dialog to select the pattern before copying Dialog for selecting a pattern after copying Optimal density pattern calculation concept (when there is overlap) Next test print range calculation conceptual diagram when there is no overlap Configuration diagram of tint block printing system Flow pattern adjustment for copy-forgery-inhibited pattern printing Flow chart showing test print parameter calculation processing Table showing two-dimensional array of dot density groups during the first test printing Table showing two-dimensional array of dot density groups at the second and subsequent test printing User input process flow overview Detailed flowchart of user input processing Table showing a two-dimensional array for storing user input values Table showing a two-dimensional array for storing user input values Table showing the two-dimensional array of FIG. 14 and FIG. Flow chart of automatic concentration calculation process

Explanation of symbols

701 Content printing unit 702 Printer driver 703 Background pattern printing unit 704 Background pattern setting unit 705 Background pattern setting unit 706 Background pattern density setting unit 707 User input unit 708 Automatic density adjustment unit 709 Test printing unit 710 Printer 711 External storage device

Claims (3)

  A copy-forgery-inhibited pattern density adjustment support program, in which the dot density of the latent image portion and the dot density of the background portion are displaced by a certain width for density adjustment, and the latent image and the background are drawn by combining these values A first step of generating a patch image, arranging the patch image in a matrix in a print area and printing a test chart, and a plurality of contrasts of a latent image portion and a background portion in the test chart within an allowable range A plurality of patch images in which the contrast between the latent image portion and the background portion is within an allowable range from the test patch in the test chart copy obtained by copying the test chart printed matter. From the plurality of patch image groups of the two series input in the third step and the second step and the third step. CFIP print density adjusting support program characterized by having a density adjustment function comprising a fourth step of one determining the optimal patch image.   The tint block print density adjustment support program according to claim 1, wherein the third step is repeated for the number of copying machines to be evaluated, and one optimum patch image is determined from a plurality of patch image groups of a plurality of series. A tint block print density adjustment support program characterized by having a density adjustment function comprising the steps of:   The copy-forgery-inhibited pattern printing density adjustment support program according to claim 2, wherein one optimum patch image can be determined from a plurality of series of patch image groups input in the second step and the third step. If there is no step, the test chart is printed again. The range of the dot density value and the displacement width of the latent image portion and the background portion of the patch image to be printed on the test chart are the dots of the plurality of series of patch images. It is calculated from a set of density values, and the degree of overlap between the acceptable patch image group after printing and the acceptable patch image group after copying is larger than that of the first test chart. Background pattern print density adjustment support program.