JP2007336354A - Image processor, control method for image processor, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor that flexibly selects a ground tint image of one resolution while generating a ground tint image with a plurality of resolutions. <P>SOLUTION: The image processor has a determination means which determines whether to generate the ground tint image with a first resolution or to generate the ground tint image with a second resolution higher than the first resolution, and a generation means that generates the ground tint image with the first resolution when determined to generate the ground tint image with the first resolution by the determination means, and also, generates the ground tint image with the second resolution when determined to generate the ground tint image with the second resolution by the determination means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, an image processing method, a program, and a medium.

  As in Patent Document 1, a printing system that generates and prints a tint block image using a computer and a printer has attracted attention. This copy-forgery-inhibited pattern image is thinner than the “region in which the image existing in the original is reproduced on the copy” and the “region in which the image existing in the original disappears on the copy, and the image in the above-described reproduced region. It is composed of two types of areas “regions that become”.

  An image area reproduced in a copy obtained by copying the original is called a “remaining portion”. In addition, an image area that disappears due to a copy or has a lower density than the reflection density of the remaining portion is referred to as an “erased portion” for convenience.

  Thus, the copy-forgery-inhibited pattern image in the original consists of the remaining portion image (residual image) and the disappeared portion image (disappearing image), and the reflection densities per fixed area are substantially equal. On the other hand, as for the copy-forgery-inhibited pattern image in the copy, only the image of the remaining portion is reproduced.

  The remaining image is configured such that dots are concentrated in a predetermined area. On the other hand, the lost image is configured such that dots are dispersed within a predetermined region (FIG. 3).

  FIG. 4 is a diagram showing the state of dots in these two image areas. As shown in the figure, dots are dispersedly arranged in the disappearing portion, and dots are concentrated in the remaining portion. The dots in these two areas are generated by different halftone dot processing and different dither processing.

  For example, when generating a copy-forgery-inhibited pattern image using halftone processing, the remaining portion performs halftone processing with a low number of lines. Further, it is preferable that the disappearing portion is subjected to halftone dot processing with a high number of lines. When a copy-forgery-inhibited pattern image is generated using dither processing, the remaining portion performs dither processing using a dot-concentrated dither matrix. Further, it is preferable to perform dither processing using a dot-dispersed dither matrix for the disappearance portion.

  FIG. 5 shows an example of a dither matrix used for dot dispersion processing and dot concentration processing. The dither matrix shown in FIG. 6A is a dither matrix for centralized processing that is used to generate an image of the remaining portion, and is composed of, for example, a window of 10 pixels in the main scanning direction and 10 pixels in the sub scanning direction. . One square in the window has a size corresponding to the diameter of the minimum dot that can be hit on the sheet when an image is formed.

  On the other hand, the dither matrix shown in (b) is a dither matrix for distributed processing that is used to generate the image of the lost portion, and is composed of, for example, a window of 16 pixels for main scanning and 16 pixels for sub scanning. As is clear from the numbers in the figure, the dither matrix used for the remaining portion is configured such that dots are concentrated in the center of the window (the number at the center is small). On the other hand, the dither matrix used for the disappearance portion is configured such that dots are dispersed (the numerical values of the windows are scattered in units of pixels).

  Incidentally, in general, a copying machine has a limit in the ability to read and reproduce minute dots on a document. If the dots in the disappearance part of the copy-forgery-inhibited pattern image in the original are formed smaller than the limit level of dots that can be reproduced by a copying machine and the dots in the remaining part are formed larger than the limit level, the dots in the remaining part on the copy are A dot that is reproduced and has a small disappearance is not reproduced. By using these characteristics, a character string such as COPY appears on a copy of the copy-forgery-inhibited pattern image. Hereinafter, the image that appears in this way is referred to as a latent image.

  There are cases where the shape of the disappearing portion is a character string and the shape of the remaining portion is a latent image.

  In addition, the phenomenon in which a latent image appears on a copy is referred to as visualization. Even if the lost part is reproduced by copying, the same effect as when dots are not reproduced can be obtained if the remaining part on the copy can be clearly recognized.

FIGS. 6A and 6B are diagrams showing this manifestation. This figure conceptually shows that the dots in the remaining portion are also revealed in the copy, and the dots in the disappearance are not reproduced in the copy. The shape of the remaining portion is C. In this case, the image of the remaining portion is a latent image.
JP 2001-197297 A

  However, in recent years, in particular, in a scanner unit and a scanner device of a multifunction machine (MFP) equipped with an inkjet engine, the reading resolution has shifted from 600 dpi to 1200 dpi and from 1200 dpi to 2400 dpi. For this reason, even if an original with a copy-forgery-inhibited pattern image generated at 600 dpi is copied, the image of the lost part is reproduced on the copy as the image of the remaining part.

  FIG. 7 schematically shows this state. FIG. 7A shows the print image data after the copy-forgery-inhibited pattern image data is generated at a resolution of 600 dpi and synthesized with the input image data.

  That is, when an original with a copy-forgery-inhibited pattern is read at a reading resolution of 600 dpi, the remaining portion where the dots are concentrated is accurately reproduced, and the disappeared portion where the dots are dispersed is not accurately reproduced. As a result, as shown in FIG. An image appears (Japanese Patent Laid-Open No. 2005-094326). However, when this original is read by a scanner having a high-resolution reading function (for example, 1200 dpi, 2400 dpi), the lost part is also accurately reproduced. As a result, the latent image does not appear. In order to solve this problem, high-resolution fine dots (for example, dots of about 21 um × about 21 um for one pixel at 1200 dpi) may be arranged in the disappearance portion.

  However, generating a high-resolution copy-forgery-inhibited pattern image does not solve all the problems. For example, it is very difficult to form very high resolution fine dots on a sheet, and therefore it is difficult to form a high resolution tint block image on a sheet. For example, in an electrophotographic image forming apparatus, toner is placed on a photosensitive drum in order to place dots on a sheet, but such small dots may not be applied. In addition, in an inkjet image forming apparatus, an excessively small amount of ink cannot be landed on a target position. Thus, even from the viewpoint of image formation, there is a problem with high-resolution copy-forgery-inhibited pattern images.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an image processing apparatus capable of generating a tint block image at a plurality of resolutions and flexibly selecting a tint block image having one resolution. Is to provide.

  In order to solve the above problems, an image processing apparatus according to the present invention has the following configuration.

  That is, determination means for determining whether to generate a copy-forgery-inhibited pattern image at the first resolution or to generate a copy-forgery-inhibited pattern image at a second resolution higher than the first resolution, and to determine the copy-forgery-inhibited pattern image at the first resolution by the determination means If it is determined that the copy-forgery-inhibited pattern image is generated at the first resolution and the determination unit determines that the copy-forgery-inhibited pattern image is generated at the second resolution, the copy-forgery-inhibited pattern image is generated at the second resolution. Generating means for generating.

  It is possible to provide an image processing apparatus capable of generating a tint block image with a plurality of resolutions and flexibly selecting a tint block image with one resolution.

(Example 1)
FIG. 13 is a block diagram showing the configuration of the tint block image generation apparatus of the present invention. Each block is centrally controlled by a CPU in the tint block image generation apparatus. Note that this tint block image generation apparatus has storage means such as a RAM, a ROM, and an HDD (not shown).

  In the figure, reference numeral 1700 denotes a data bus through which input document image data passes. In the copying machine, this document image data corresponds to read image data sent from a scanner device such as a CCD or CIS (at this time, the copy-forgery-inhibited pattern image has not yet been synthesized).

  Reference numeral 1702 denotes an operation unit, which corresponds to the operation panel. The user uses the screen displayed on the operation unit to select a character string desired as a latent image, select a font of the character string, select a camouflage pattern, or execute density adjustment. Can be instructed and the resolution can be specified. Among these, even with a conventional machine that can generate a tint block image only at a single resolution, the density adjustment of the tint block image could be executed (see Japanese Patent Application Laid-Open No. 2005-91730).

  FIG. 12A shows an example of a display screen displayed on the operation unit 1702 when the user performs tint block printing. In FIG. 12A, reference numeral 1601 denotes a menu bar, and reference numeral 1602 denotes a check column checked by the user when performing copy-forgery-inhibited pattern printing. Reference numeral 1603 denotes a field for setting a character string to be embedded as a latent image. In the example of FIG. 16, “VOID” is set. Reference numeral 1605 denotes a part for designating at which resolution the tint block data is generated, and in the figure, it is shown that the resolution can be designated in a pull-down state. In this field, the resolution of the copy-forgery-inhibited pattern image data can be set to high resolution (1200 dpi) or low resolution (600 dpi).

  FIG. 12B shows an example of a display screen displayed on the operation unit 1702 when the user selects a font of a character string to be embedded as a latent image. Reference numeral 1606 denotes a menu bar, and font types, font sizes, and font colors can be set using 1607, 1608, and 1609.

  Reference numeral 1701 denotes a parameter determination unit. Based on information designated by the user in the operation unit 1702, the parameter determination unit 1701 determines a resolution for generating a tint block image. Further, parameters necessary for generating a copy-forgery-inhibited pattern image with the determined resolution are read from a storage unit (not shown) and sent to the copy-forgery-inhibited pattern data generation unit 1707. The storage means includes a dither matrix for generating a residual image, a density value applied to the dither matrix, a dither matrix for generating a lost image, and a density applied to the dither matrix. Four types of parameters such as values are stored.

  In the conventional apparatus that can generate a copy-forgery-inhibited pattern image only at a low resolution (600 dpi), the above four types of parameters are stored one by one. On the other hand, since the tint block image generating apparatus according to the present invention can generate tint block images with a plurality of resolutions, a plurality of sets of the above four types of parameters are stored. For example, if a copy-forgery-inhibited pattern image can be generated at five resolutions, five sets of the above four types of parameters are stored.

  Reference numeral 1707 denotes a tint block data generation unit. The copy-forgery-inhibited pattern data generation unit 1707 sets information selected by the user in the operation unit 1702, and generates copy-forgery-inhibited pattern image data using the set information and the parameters sent from the parameter determination unit 1701. Note that the information selected by the user on the operation unit 1702 is a character string to be a latent image, a font of the character string, and a camouflage pattern. In the next paragraph, a process for generating copy-forgery-inhibited pattern image data using the set information and parameters will be described in detail.

  The copy-forgery-inhibited pattern data generation unit 1707 first performs dot concentration processing using the residual image parameters (concentrated dither matrix and density value to be added thereto) held in the parameter selection unit 1707, and performs the residual image processing. Generate a binary pattern. The copy-forgery-inhibited pattern data generation unit 1707 uses the parameters for the lost image (dispersion-type dither matrix and the density value to be added thereto) held in the parameter holding unit 1707 to perform dot dispersion processing and perform background image use. Generate a binary pattern of Then, the binary pattern for the remaining portion and the binary pattern for the background portion are arranged based on the set information (a character string to be used as a latent image, a font of the character string, and a camouflage pattern). To do. As a result, copy-forgery-inhibited pattern image data is generated.

  1708 synthesizes the input image data 1701 and the copy-forgery-inhibited pattern image data generated by the copy-forgery-inhibited pattern data generation unit 1707 to generate output image data (original data).

  An image forming unit 1709 forms an image of the received original data. In the present embodiment, this image forming unit can place 1200 dpi dots in both the sub-scanning direction and the main scanning direction.

  Heretofore, a case where a copy-forgery-inhibited pattern image is generated by a copying machine has been described. However, for example, a copy-forgery-inhibited pattern image can be generated even in the relationship between the host and the printer. In this case, the input image data 1701 corresponds to post-development data of image data (PDL) based on an object input from a PC. The operation unit 1702 corresponds to a keyboard, 1703 to a monitor, and 1704 to a menu screen of a driver installed in the PC.

  Next, the operation of the copy-forgery-inhibited pattern image generation apparatus of the present invention will be described based on the operation flow. FIG. 10 is a diagram showing a processing flow in the first embodiment of the present invention. The processing in each step is comprehensively controlled by the CPU in the tint block image generation device.

  When copy-forgery-inhibited pattern printing is set, the following processing starts.

  In step 101, the parameter determination unit 1701 determines the resolution designated by the user using FIG. If the resolution is low, the process proceeds to step 102. If the resolution is high, the process proceeds to step 104.

  In step 102 (in the case of low resolution), the parameter determination unit 1701 reads out parameters necessary for generating a copy-forgery-inhibited pattern image at 600 dpi from a storage unit (not shown), sends it to the copy-forgery-inhibited pattern data generation unit 1707, and proceeds to step 103. . Specifically, a dither matrix (dot concentrated dither matrix) for generating a residual image as shown in FIG. 5A or a dither matrix for generating a lost image as shown in FIG. 5B. (Dot-dispersed dither matrix) is read from the storage means. Further, the density value added to each dither matrix is read from the storage means. Then, each read parameter is sent to the tint block data generation unit 1707. One pixel of the dither matrix shown in FIGS. 5A and 5B corresponds to a 600 dpi (about 42 um) dot.

  In step 103 (in the case of low resolution), the tint block data generation unit 1707 sets information selected by the user in the operation unit 1702 (a character string desired to be a latent image, a font of the character string, and a camouflage pattern). Further, based on the parameters sent from the parameter determination unit 1701, a dot pattern for the remaining image data and a dot pattern for the lost image data are generated. Specifically, a dot pattern for the remaining image data is generated by adding the density value for the remaining portion to the dither matrix for the remaining portion. Further, the dot value for the lost image data is generated by adding the density value for the lost portion to the dither matrix for the lost portion. Then, each generated dot pattern is arranged based on set information (a character string desired to be a latent image, a font of the character string, a camouflage pattern), and 600 dpi copy-forgery-inhibited pattern image data is generated. 1708. Thereafter, the combining unit 1708 combines the document image data and the copy-forgery-inhibited pattern image data to generate combined image data.

  In step 104 (in the case of high resolution), the parameter determination unit 1701 reads parameters necessary for generating a copy-forgery-inhibited pattern image at 1200 dpi from a storage unit (not shown), and sends the parameters to the copy-forgery-inhibited pattern data generation unit 1707. Specifically, a dither matrix (dot concentrated dither matrix) for generating a residual image as shown in FIG. 2A or a dither matrix for generating a lost image as shown in FIG. 2B. (Dot-dispersed dither matrix) is read from the storage means. Further, the density value added to each dither matrix is read from the storage means. Then, the read parameters are sent to the copy-forgery-inhibited pattern data generation unit 1707, and the process proceeds to step 105. One pixel of the dither matrix shown in FIGS. 2A and 2B corresponds to a 1200 dpi (about 21 um) dot.

  In step 105 (in the case of high resolution), the tint block data generation unit 1707 sets information selected by the user on the operation unit 1702 (a character string desired to be a latent image, a font of the character string, and a camouflage pattern). Further, based on the parameters sent from the parameter determination unit 1701, a dot pattern for the remaining image data and a dot pattern for the lost image data are generated. Specifically, a dot pattern for the remaining image data is generated by adding the density value for the remaining portion to the dither matrix for the remaining portion. Further, the dot value for the lost image data is generated by adding the density value for the lost portion to the dither matrix for the lost portion. Then, the generated dot patterns are arranged based on set information (a character string to be a latent image, a font of the character string, a camouflage pattern), and 1200 dpi copy-forgery-inhibited pattern image data is generated. 1708. Thereafter, the combining unit 1708 combines the document image data and the copy-forgery-inhibited pattern image data to generate combined image data.

  FIG. 15 is a diagram illustrating processing blocks for performing subsequent processing on the composite image data.

  Reference numeral 1501 denotes a binarization unit that binarizes the composite image data. As described above, the copy-forgery-inhibited pattern image data is generated in a state binarized by the copy-forgery-inhibited pattern data generation unit. Therefore, it is not necessary to binarize the binarization unit 1501 again. On the other hand, reference numeral 1502 denotes a binarization unit that binarizes the composite image data. Reference numeral 1503 denotes an output unit that outputs an image binarized by the binary unit. The output unit can output an image on a sheet or transmit and output an image using a transmission technique such as E-MAIL based on an instruction from a user.

  As described above, in the first embodiment, high-resolution copy-forgery-inhibited pattern image data can be generated. As a result, even when scanned with a scanner having a high-resolution scanning function, it is possible to form a tint block image that achieves a copy restraining effect. Furthermore, not only high resolution but also low resolution copy-forgery-inhibited pattern image data can be generated, and the user can freely select high resolution or low resolution to generate copy-forgery-inhibited pattern image data.

(Example 2)
In the first embodiment, a configuration capable of generating high-resolution copy-forgery-inhibited pattern image data and low-resolution copy-forgery-inhibited pattern image data has been shown. In this configuration, since the high-resolution copy-forgery-inhibited pattern image data can be generated, the dots in the lost portion become smaller. Therefore, even if the copy-forgery-inhibited pattern image is read by a scanner having a high-resolution copy function, The image can be formed.

  For this reason, it seems that there are no disadvantages in generating high resolution copy-forgery-inhibited pattern image data and forming an image. In practice, however, the high-resolution copy-forgery-inhibited pattern image data also has drawbacks. In electrophotographic printers, even if you try to hit too small dots, the toner may not fall on the paper. Inkjet printers may not hit ink accurately if you try to hit too small dots. This is because there are cases. In other words, even if the copy-forgery-inhibited pattern image data with too high resolution is generated, the image may not be accurately formed on the sheet.

  Such a problem seems to be solved by applying a tint block density adjustment technique, but in reality, it is not so simple. This is because it is terrible for the user to use the background pattern density adjustment (background pattern calibration) technique as described in Japanese Patent Application Laid-Open No. 2005-094326 every time.

  Therefore, in this embodiment, the default tint block resolution is set to 600 dpi. Nevertheless, if the user instructed to generate the copy-forgery-inhibited pattern image data at 1200 dpi, the instruction is accepted and it is determined whether or not the copy-forgery-inhibited pattern calibration is necessary. In this case, the copy-forgery-inhibited pattern image data is generated at 1200 dpi. On the other hand, if it is determined that it is necessary, the user is warned that the background pattern density adjustment is necessary, and the user is allowed to select the subsequent processing.

  FIG. 8 is a diagram showing a processing flow in the second embodiment of the present invention. The processing in each step is comprehensively controlled by the CPU in the tint block image generation device.

  In step 1201, the parameter determination unit 1701 determines whether a high resolution is designated by the user using (a) of FIG. If the high resolution is not specified (including the case where the user does not select the resolution), the process proceeds to step 102. If the high resolution is specified, the process proceeds to step 104.

  In step 1202 (when high resolution is not designated), the parameter determination unit 1701 reads out parameters necessary for generating a copy-forgery-inhibited pattern image at 600 dpi from a storage unit (not shown), and sends the parameters to the copy-forgery-inhibited pattern data generation unit 1707. 103. Specifically, a dither matrix (dot concentrated dither matrix) for generating a residual image as shown in FIG. 5A or a dither matrix for generating a lost image as shown in FIG. 5B. (Dot-dispersed dither matrix) is read from the storage means. Further, the density value added to each dither matrix is read from the storage means. Then, each read parameter is sent to the tint block data generation unit 1707. One pixel of the dither matrix shown in FIGS. 5A and 5B corresponds to a 600 dpi (about 42 um) dot.

  In step 1203 (when high resolution is not designated), the copy-forgery-inhibited pattern data generation unit 1707 selects information selected by the user in the operation unit 1702 (character string desired to be a latent image, font of the character string, camouflage pattern). Set. Further, based on the parameters sent from the parameter determination unit 1701, a dot pattern for the remaining image data and a dot pattern for the lost image data are generated. Specifically, a dot pattern for the remaining image data is generated by adding the density value for the remaining portion to the dither matrix for the remaining portion. Further, the dot value for the lost image data is generated by adding the density value for the lost portion to the dither matrix for the lost portion. Then, each generated dot pattern is arranged based on set information (a character string desired to be a latent image, a font of the character string, a camouflage pattern), and 600 dpi copy-forgery-inhibited pattern image data is generated. 1708.

  In step 1204 (in the case of high resolution), it is determined whether ground pattern calibration is necessary. As a result of the determination, if it is determined that it is not necessary, the process proceeds to step 1206. If it is determined that it is necessary, the process proceeds to step 1205.

  Note that when determining whether the background pattern calibration is necessary, the determination is made based on how many times printing has been performed after the previous background pattern calibration. This is because density fluctuations easily occur in the image forming unit of the device when the number of times of printing is large.

  Further, in determining whether the tint block calibration is necessary, it may be performed based on how much time has passed since the previous tint block calibration was performed.

  Also, when determining whether copy-forgery-inhibited pattern calibration is necessary, a test patch for a copy-forgery-inhibited pattern image is placed on the photosensitive drum, the reflection density of the test patch is read by patch detection, and a determination based on the reflection density result is performed. Also good. The patch detection is a detector that irradiates the toner on the photosensitive drum with light and measures the reflection density from the reflection level of the light.

  In step 1206, the parameter determination unit 1701 reads out parameters necessary for generating a copy-forgery-inhibited pattern image at 1200 dpi from a storage unit (not shown) and sends the read-out parameters to the copy-forgery-inhibited pattern data generation unit 1707. Specifically, a dither matrix (dot concentrated dither matrix) for generating a residual image as shown in FIG. 2A or a dither matrix for generating a lost image as shown in FIG. 2B. (Dot-dispersed dither matrix) is read from the storage means. Further, the density value added to each dither matrix is read from the storage means. Then, the read parameters are sent to the copy-forgery-inhibited pattern data generation unit 1707, and the process proceeds to step 105. One pixel of the dither matrix shown in FIGS. 2A and 2B corresponds to a 1200 dpi (about 21 um) dot.

  In step 1207 (in the case of high resolution), the copy-forgery-inhibited pattern data generation unit 1707 sets information (character string desired to be a latent image, font of the character string, and camouflage pattern) selected by the user in the operation unit 1702. Further, based on the parameters sent from the parameter determination unit 1701, a dot pattern for the remaining image data and a dot pattern for the lost image data are generated. Specifically, a dot pattern for the remaining image data is generated by adding the density value for the remaining portion to the dither matrix for the remaining portion. Further, the dot value for the lost image data is generated by adding the density value for the lost portion to the dither matrix for the lost portion. Then, the generated dot patterns are arranged based on set information (a character string to be a latent image, a font of the character string, a camouflage pattern), and 1200 dpi copy-forgery-inhibited pattern image data is generated. 1708. The copy-forgery-inhibited pattern image data generated in this way is finally sent to the image forming unit 1709 to form an image. That is, a tint block image in which dots of about 21 μm are arranged in the disappearing portion is formed on the sheet.

  In step 1205, control is performed so that a warning screen is displayed on the display screen of the operation unit 1702. Specifically, the warning screen is as shown in FIG. That is, the user is notified that there is a possibility that the copy-forgery-inhibited pattern image cannot be printed out accurately, and the user is made to select the subsequent processing.

  If it is determined that the user has pressed the tab “Forced”, the process proceeds to step 1206 to perform high-resolution copy-forgery-inhibited pattern printing. If it is determined that the tab “Cancel” is pressed by the user, the process proceeds to step 1202 where low-resolution background pattern printing is performed. If the user presses the tab “Change to 600 dpi”, the process proceeds to step 1201.

  In the second embodiment described above, low-resolution copy-forgery-inhibited pattern printing that does not require much calibration is set as a default setting. Further, when the high resolution copy-forgery-inhibited pattern printing is selected by the user and when calibration is not necessary, high-resolution copy-forgery-inhibited pattern printing is performed.

  With this setting, a normal user can obtain a copy-forgery-inhibited pattern image in which the reflection density in the remaining part and the disappearing part is adjusted to be approximately equal. Furthermore, it is possible to obtain a copy-forgery-inhibited pattern image (high-resolution copy-forgery-inhibited pattern image) in which the dots in the lost portion disappear firmly on the copy as necessary. Here, the fact that the dots at the disappearing portion disappear firmly on the copy means that the latent image appears even if the dot is copied by a copying machine having a high resolution reading function.

(Example 3)
Example 3 will be described. In the first embodiment, the user designates the resolution of the copy-forgery-inhibited pattern image data to be printed. In the present embodiment, an environment in which the resolution of a copying machine (such a copying machine will be referred to as a target hereinafter) to which the original is copied, such as a user who has only a 600 dpi copying machine in the company office, can be predicted. Assumed.

  FIG. 14 shows an example of a display screen displayed on the operation unit 1702 in order for the user to specify the target resolution on the operation unit 102.

  In the figure, 1801 is a menu bar, 1802 is a check column for setting target designation on / off, and 1803 is an area for designating the resolution of a target, for example, a pull-down menu. As for the resolution portion of the target, a resolution that can be printed by the system or apparatus is displayed. For example, in the case of an electrophotographic printer, the resolution corresponding to the controllable range of the PWM control of the laser width is displayed, and in the case of an inkjet printer, it can be controlled by ink discharge amount and print head restrictions. The corresponding resolution is displayed.

  In the apparatus of the present invention, when the target resolution is designated, the parameter determination unit 1701 reads out the parameter corresponding to the designated resolution from the storage means and sends it to the tint block data generation unit 1707. The tint block data generation unit 1707 generates a tint block image based on the parameters sent from the parameter determination unit 1701 as in the first and second embodiments.

  Normally, when the reading resolution of the copying machine is 600 dpi, it is impossible to reproduce a dot of 600 dpi level (82 um level). In general, when the reading resolution of the copying machine is 1200 dpi, it is impossible to reproduce the dots at the 1200 dpi level (41 um level). In general, when the reading resolution of the copying machine is 2400 dpi, it is impossible to reproduce 2400 dpi level (41 um level) dots. Therefore, it is desirable to generate a copy-forgery-inhibited pattern image having the same resolution as the target resolution specified by the user.

Example 4
Example 4 will be described. In the first embodiment, the user designates the resolution of the copy-forgery-inhibited pattern image data to be printed. However, the user cannot confirm the copy suppression effect of the copy-forgery-inhibited pattern image data by the resolution designation. Therefore, the operation of the apparatus of the present invention for the user to confirm the copy suppression effect will be described below.

  When the resolution of the copy-forgery-inhibited pattern image data to be printed is specified by the user, the apparatus of the present invention determines whether or not to display a warning screen on the operation unit 1702, and displays the warning screen if the result of determination is to be displayed. To control. The display content is, for example, as shown in FIG.

  The display message is not limited as long as it can be recognized by the user. That is, the message is not limited to the message shown in FIG. At this time, a visual display such as an LED may be turned on or blinked in combination with the message. When the user gives an instruction to continue image output, the tint block data generation unit 109 generates tint block image data using parameters according to the resolution of the set tint block image data.

(Example 5)
The fifth embodiment will be described. In the first embodiment, the user designates the resolution of the copy-forgery-inhibited pattern image data to be printed. However, not only the resolution of the copy-forgery-inhibited pattern image data but also the dot size of the remaining portion may be specified.

  When the dot size of the remaining portion is designated in this way, the tint block data generation unit generates the remaining image data with the designated dot size, and also generates the tint block image data of the lost portion with the designated resolution. It will be. In this case, depending on the combination, there is a possibility that the copy suppression effect of the generated tint block image data or the output image quality may not be as intended by the user. This is because if the dot size of the remaining portion is too small, it may not be reproduced on the copy, and if the dot size of the remaining portion is too large, the dots in the remaining portion will be conspicuous on the original, and the latent image This is because it becomes visible.

  When the resolution of the copy-forgery-inhibited pattern image data to be generated and the dot size of the remaining portion are designated, the device of the present invention determines whether or not it is necessary to display a warning screen on the operation unit 1702, and it is necessary to display the result of the determination. If it is determined, control is performed to display. The display content is, for example, as shown in FIG. Note that if the dot size of the remaining portion is too large, the latent image in the original may become noticeable, so control is performed to display that effect. If the dot size of the remaining portion is too small, the latent image on the copy may not be noticeable. Whether or not the warning screen needs to be displayed is determined based on the dot size. Specifically, when the dot size becomes larger than the first size, control is performed so as to display a display screen as shown in FIG. Further, when the dot size becomes smaller than the second size, control is performed so as to display a display screen as shown in FIG. However, the first size is set larger than the second size.

(Other examples)
In each of the above-described embodiments, description has been made assuming that a tint block image can be generated with high resolution (1200 dpi) and low resolution (600 dpi). However, the present invention is not limited to two resolutions, and a plurality of three or more resolution designations may be possible. For example, it may be possible to specify four resolutions such as 2400, 1200, 600, and 300.

  The present invention can be applied to all image processing apparatuses that have a CPU and storage means such as a copying machine and a multifunction peripheral and can process images.

  A control method for causing the CPU of the image processing apparatus to execute each step of the flowchart described with reference to the drawings is also a part of the present invention.

  A program for causing the CPU of the image processing apparatus to execute each step is part of the present invention.

  A computer-readable storage medium storing such a program is also a part of the present invention.

(A) is an example of a warning screen, (b) is an example of a warning screen (A) is an example of a dither matrix used for generating a remaining portion of a high-resolution copy-forgery-inhibited pattern image, and (b) is an example of a dither matrix used for generating a lost portion of a high-resolution copy-forgery-inhibited pattern image. Part of tint block image A diagram showing dots on the remaining and disappearing parts of the tint block (A) is an example of a dither matrix used for generating a remaining portion of a low-resolution copy-forgery-inhibited pattern image, and (b) is an example of a dither matrix used for generating a lost portion of a low-resolution copy-forgery-inhibited pattern image. (A) is a diagram showing a tint block image, (b) is a diagram showing a tint block image in which a latent image is revealed. Conceptual diagram showing problems with conventional devices Flowchart for explaining the second embodiment Example of warning screen Flowchart for explaining the first embodiment Example of warning screen (A) Example of copy-forgery-inhibited pattern print setting screen, (b) Example of latent image font designation screen Block diagram of tint block image generator Illustration for specifying target resolution The figure which showed the processing block which processes with respect to the image data after composition

Claims (16)

Determining means for determining whether to generate a copy-forgery-inhibited pattern image at a first resolution or to generate a copy-forgery-inhibited pattern image at a second resolution higher than the first resolution;
If the determination unit determines that the copy-forgery-inhibited pattern image is generated at the first resolution, the copy-forgery-inhibited pattern image is generated at the first resolution;
An image processing apparatus comprising: a generation unit configured to generate a tint block image at the second resolution when the determination unit determines to generate the tint block image at the second resolution. The determination means includes
Determining means for determining whether density adjustment is necessary when generating a tint block image at the second resolution;
When the determination means determines that density adjustment is necessary, it is determined to generate a copy-forgery-inhibited pattern image at the first resolution;
The image processing apparatus according to claim 1, further comprising: a second determination unit that determines to generate a copy-forgery-inhibited pattern image at the second resolution when the determination unit determines that density adjustment is not necessary. . The determination means includes
Based on the number of printings performed after the previous density adjustment for generating the tint block image at the second resolution, the density adjustment is necessary when generating the tint block image at the second resolution. The image processing apparatus according to claim 2, further comprising: The determination means includes
Whether density adjustment is necessary when generating a tint block image at the second resolution based on an elapsed time after the previous density adjustment for generating the tint block image at the second resolution The image processing apparatus according to claim 2, wherein: Image forming means for forming an image of the tint block image generated by the generating means on a sheet;
The determination means includes
It is determined whether the user has selected to prioritize the degree of latent image concealment in the copy-forgery-inhibited pattern image formed on the sheet by the image forming unit, and based on the determination, the copy-forgery-inhibited pattern image is generated at the first resolution. The image processing apparatus according to claim 1, wherein it is determined whether to generate a copy-forgery-inhibited pattern image at a second resolution higher than the first resolution. Image forming means for forming an image of the tint block image generated by the generating means on a sheet;
The determination means includes
It is determined whether or not the user has selected to prioritize the appearance level of the latent image in the copy of the tint block image formed on the sheet by the image forming unit, and based on the determination, the first resolution The image processing apparatus according to claim 1, wherein it is determined whether to generate a copy-forgery-inhibited pattern image or to generate a copy-forgery-inhibited pattern image at the second resolution. Image forming means for forming an image of the tint block image generated by the generating means on a sheet;
The determination means includes
A copy-forgery-inhibited pattern image is generated at the first resolution or a copy-forgery-inhibited pattern image at the second resolution according to the resolution of the copying machine that will copy the copy-forgery-inhibited pattern image formed on the sheet by the image forming unit. The image processing apparatus according to claim 1, wherein it is determined whether to generate the image processing apparatus. A determination step of determining whether to generate a copy-forgery-inhibited pattern image at a first resolution or to generate a copy-forgery-inhibited pattern image at a second resolution higher than the first resolution;
If it is determined in the determination step that the copy-forgery-inhibited pattern image is generated with the first resolution, the copy-forgery-inhibited pattern image is generated with the first resolution;
And a generation step of generating a tint block image at the second resolution when it is determined in the determination step that the tint block image is generated at the second resolution. The determination step includes
A determination step of determining whether density adjustment is necessary when generating the copy-forgery-inhibited pattern image at the second resolution;
When it is determined that the density adjustment is necessary in the determination step, it is determined that the copy-forgery-inhibited pattern image is generated with the first resolution;
The image processing apparatus according to claim 8, further comprising: a second determination step that determines that a tint block image is generated at the second resolution when it is determined that density adjustment is not necessary in the determination step. Control method. The determination step includes
Based on the number of printings performed after the previous density adjustment for generating the tint block image at the second resolution, the density adjustment is necessary when generating the tint block image at the second resolution. The method of controlling an image processing apparatus according to claim 9, wherein: The determination step includes
Whether density adjustment is necessary when generating a tint block image at the second resolution based on an elapsed time after the previous density adjustment for generating the tint block image at the second resolution The method of controlling an image processing apparatus according to claim 9, wherein: An image forming step of forming an image of the copy-forgery-inhibited pattern image generated in the generating step on a sheet;
The determination step includes
It is determined whether the user has chosen to prioritize the concealment degree of the latent image in the copy-forgery-inhibited pattern image formed on the sheet in the image forming step, and based on the determination, the copy-forgery-inhibited pattern image is generated at the first resolution. 9. The method of controlling an image processing apparatus according to claim 8, wherein whether the copy-forgery-inhibited pattern image is generated at a second resolution higher than the first resolution is determined. An image forming step of forming an image of the copy-forgery-inhibited pattern image generated in the generating step on a sheet;
The determination step includes
In the image forming step, it is determined whether the user has selected to prioritize the appearance level of the latent image in the copy of the copy-forgery-inhibited pattern image formed on the sheet, and the first resolution is determined based on the determination. 9. The method of controlling an image processing apparatus according to claim 8, wherein whether to generate a copy-forgery-inhibited pattern image or to generate a copy-forgery-inhibited pattern image at the second resolution is determined. An image forming step of forming an image of the copy-forgery-inhibited pattern image generated in the generating step on a sheet;
The determination step includes
A copy-forgery-inhibited pattern image is generated at the first resolution or a copy-forgery-inhibited pattern image at the second resolution according to the resolution of the copying machine that will copy the copy-forgery-inhibited pattern image formed on the sheet in the image forming step The method for controlling an image processing apparatus according to claim 8, wherein whether to generate the image processing apparatus is determined.   The program for making a computer perform each process in the control method of the image processing apparatus in any one of Claims 8 thru | or 14.   A computer-readable storage medium storing the program.

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