JP2008028777A - Image forming apparatus and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and a control method thereof that cannot establish image processing of disabling a design pattern effect to images with design patterns and warrants the design patterns by prioritizing the design pattern effect even when the image processing is established. <P>SOLUTION: The image forming apparatus for forming an image on the basis of image data attached with design pattern image data representing design patterns manifested by copying discriminates whether or not the image data are attached with the design pattern image data and limits image processing affecting the attached design pattern image data when it is discriminated that the design pattern image data are attached to the image data. For example, if there is density adjustment, hue adjustment, saturation adjustment, color balance, or overlapping design settings, it is inhibited or a user is notified of it by alarming. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus. More particularly, the present invention relates to a process for printing an image including a tint block image for clearly distinguishing an original from a copy in an image forming apparatus having an image input apparatus for inputting an image from a scanner and a computer and a printing apparatus such as a printer. It is.

  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. This forgery-preventing paper is hard to be seen by humans in the original, but is a paper on which characters such as “prohibited copying” appear when copying using a copying machine or the like. As a result, the effect of making the copy person hesitant to use the copy is produced. Furthermore, it is assumed that such a form or the like is printed on forgery-preventing paper, so that the effect of inhibiting and checking the copy itself is also produced.

  However, such anti-counterfeit paper has a problem that it is more expensive than ordinary paper. Further, only characters set at the time of production of the anti-counterfeit paper can be raised, and the use of the paper is limited.

  On the other hand, as various contents are digitized, contents such as forms and resident's cards are also digitized. However, the digitization of these forms and resident's forms themselves is still in a transitional period, and content created using a computer is often output and used on paper using a printer or the like.

  In response to such a situation, attention has been paid to a technique for generating anti-counterfeit paper, which has been prepared in advance by plate making or the like, using a computer and a printer (Patent Document 1). This is a technique for generating image data called a tint block in addition to content data when printing and outputting content created using a computer, and outputting these data in an overlapping manner. The background pattern is sometimes called a copy check pattern. The copy-forgery-inhibited pattern image appears as a simple pattern or background image to the human eye in the original (printed matter output by the printer), but when copied, predetermined characters and images are visualized. And this original can give the same check effect as said forgery prevention paper. This is possible due to a dramatic improvement in printer performance.

  When a copy-forgery-inhibited pattern image created using a computer is output overlaid on content data, it can of course be output using normal printing paper, etc. There are advantages in terms. Furthermore, since a copy-forgery-inhibited pattern image can be generated when the content data is printed out, it is possible to freely determine not only the color of the copy-forgery-inhibited pattern image but also characters to be visualized when copying the original. Another advantage is that the output date and time, information specific to the printing apparatus, and the like can be used as the tint block image.

  Now, as described above, the copy-forgery-inhibited pattern image realizes an effect of suppressing the use of the copied material, etc., when the original is copied, a predetermined character that cannot be recognized before copying becomes obvious. is there.

  In order to realize this effect, the generated copy-forgery-inhibited pattern image basically includes an area in which the same image as the original remains in the copy and an image existing in the original in the copy disappears or the above remaining area. It is composed of two areas that are thinner than the image. The copy-forgery-inhibited pattern image composed of the two areas is preferably set to have substantially the same density in the two areas in a state where the image is printed out. In other words, the printed copy-forgery-inhibited pattern image needs to be configured so that it is difficult for humans to visually recognize that characters to be visualized on a copy are hidden. An image area that is hidden in the printed output of the copy-forgery-inhibited pattern image but appears to be visually recognizable by humans in a copy of the printed output is called a “latent image (or latent image)”. In addition, an image area having a lower density than the density of a latent image that disappears with a copy or is visualized with the copy is referred to as a “background (or background image)” for convenience. The copy-forgery-inhibited pattern image basically consists of the latent image and the background image. In some cases, the latent image is called a foreground as a term on the user interface.

  The latent image is configured so that dots are concentrated in a predetermined area. On the other hand, the background portion is configured such that dots are dispersed within a predetermined area. By configuring so that the density of dots in this region is substantially the same, it is possible to make it difficult to distinguish the latent image portion from the background portion in the printed output of the tint block image.

  FIG. 25 is a diagram showing the state of dots in these two image areas. As shown in the figure, a tint block image is composed of a background portion in which dots are dispersed in a predetermined area and a latent image portion in which dots are concentrated. The dots in these two regions can be generated by different halftone dot processing and different dither processing. For example, when a tint block image is generated using halftone processing, the latent image portion performs halftone processing with a low number of lines. In addition, it is preferable that the background portion performs halftone dot processing with a high number of lines. Furthermore, when a copy-forgery-inhibited pattern image is generated using dither processing, the latent image portion performs dither processing using a dot-concentrated dither matrix. Further, it is preferable that the background portion performs dither processing using a dot dispersion type dither matrix.

  In general, a reading unit and an image forming unit of a copying machine have a limit level of reproducibility depending on an input resolution for reading minute dots on an original and an output resolution for reproducing minute dots. If the dots in the background portion of the copy-forgery-inhibited pattern image are formed smaller than the limit level of the dots that can be reproduced by the copying machine and the dots in the latent image portion are formed larger than the limit level, the dots in the latent image portion on the copy are Can be reproduced and small dots in the background are not reproduced. By utilizing these characteristics, the latent image becomes apparent on a copy of the copy-forgery-inhibited pattern image. Hereinafter, an image that appears on a copy is referred to as a visible image. Even if the background portion is reproduced by copying, the same effect as when dots are not reproduced can be obtained as long as the latent image portion on the copy can be clearly recognized.

  (A) and (b) of FIG. 26 are diagrams showing this visualization. This figure conceptually shows that when the dots are concentrated, the image is also visualized in the copy, and when the dots are dispersed, it is not reproduced in the copy.

Note that copy-forgery-inhibited pattern printing is not limited to the above-described configuration, and it is sufficient that a character string or the like can be reproduced on a copy at a recognizable level. That is, even if a character string or the like is designated as the background portion and is shown in a state like a white character at the time of copying, the purpose of the tint block printing is achieved.
JP 2001-197297 A

  By adding a copy-forgery-inhibited pattern image to a document image and performing printing, a copy-forgery-inhibited pattern image printing with a high degree of freedom can be realized at a low cost. Various image processes to be performed on the image are also performed on the copy-forgery-inhibited pattern image.

  That is, density processing, hue adjustment, and saturation adjustment processing are performed, so that it is impossible to guarantee density fluctuations in the background pattern portion and M, C, and K pure colors in the background pattern portion, and the background pattern appears to appear during the first print. Or, when copying a grandchild, there is a risk that the image will not appear because the background will not be skipped and the color will not be skipped.

  For example, when the output density is increased by changing the density of the copy-forgery-inhibited pattern image, the density of the latent image portion and the background portion of the copy-forgery-inhibited pattern is increased. In the dither processing for pixels having a predetermined density in the background portion, dots can be dispersedly arranged. However, in the dither processing for high density pixels, dots are arranged in a concentrated manner and exceed the readable level. For this reason, when the printed image is read by the reading unit of the copying machine, the background portion is reproduced and the background pattern effect is lost.

  On the other hand, when the density is lowered, the dot shape is discretized in the dither processing for the lower density. For this reason, if the dots in the latent image portion are discretized, there is a possibility that the image cannot be reproduced at the time of reading, or the background portion pixels are not output at the time of copy-forgery-inhibited pattern printing, and the character is output from the first print.

  Further, the color components of the background portion and latent image portion of the tint block must be set so that only the primary colors of C (cyan), M (magenta), and K (black) are printed and not mixed. This is because the error diffusion method used as dither processing is a method of comparing the pixel value of a pixel to be binarized and the error allocated to the pixel value with a predetermined threshold value to determine dot ON / OFF. This is because. That is, in the generation of black dots at the start of the low density region and the generation of white dots at the start of the high density region, the dot generation is significantly delayed until a large amount of errors are accumulated and the steady state is reached. Therefore, problems such as a delay in dot generation and tailing in which a large amount of accumulated error is diffused to the outside of the region occur. Therefore, there is a possibility that the boundary between the latent image portion and the background portion is disturbed and the tint block image is deteriorated. If processing such as hue adjustment and saturation adjustment is performed, the background pattern density cannot be guaranteed, and the primary colors of M, C, and K in the background pattern portion cannot be guaranteed, and an image without a background pattern effect can be output. There is sex.

  In view of the above-mentioned conventional problems, the present invention cannot set image processing that eliminates the background pattern effect for an image to which a background pattern has been added. Even when the image processing is set, the background pattern effect is given priority to guarantee the background pattern. An image forming apparatus and a control method thereof are provided.

  In order to solve the above problems, an image forming apparatus of the present invention is an image forming apparatus that forms an image based on image data to which a tint block image data indicating a tint block image visualized by copying is added. And determining means for determining whether or not a copy-forgery-inhibited pattern image data is to be added, and limiting means for restricting image processing affecting the added copy-forgery-inhibited pattern image data when it is determined that the copy-forgery-inhibited pattern image data is added. And

  Here, the image forming apparatus further includes adding means for adding copy-forgery-inhibited pattern image data, and the determining means determines whether or not the adding means is operating. The determination unit determines whether to add the copy-forgery-inhibited pattern image data in accordance with an input instruction for adding a copy-forgery-inhibited pattern from the operation unit. The determination unit determines whether to add the copy-forgery-inhibited pattern image data according to the copy-forgery-inhibited pattern addition information included in the image data from the external device. The image data from the external device includes PDL data. The restricting unit includes a prohibiting unit that prohibits setting of image processing that affects the added copy-forgery-inhibited pattern image data when the determination unit determines that the copy-forgery-inhibited pattern image data is added. The restricting means includes warning means for giving a warning when image processing affecting the added copy-forgery-inhibited pattern image data is set. The image processing that affects the added tint block image data includes at least one of density adjustment, hue adjustment, saturation adjustment, and color balance. The image processing that affects the added copy-forgery-inhibited pattern image data further includes overlapping copy-forgery-inhibited pattern settings. The limiting means limits the density adjustment by the limitation of the gamma correction means, limits the hue and saturation adjustment by the limits of the hue / saturation adjusting means, and limits the color balance by limiting the output color correction means. To do. The copy-forgery-inhibited pattern includes a latent image in an area that is visualized by copying and a background image that does not change by copying in an area excluding the latent image.

  A control method for an image forming apparatus according to the present invention is a control method for an image forming apparatus for forming an image based on image data to which a copy-forgery-inhibited pattern image data representing a copy-forgery-inhibited pattern image is formed. A determination step for determining whether or not a copy-forgery-inhibited pattern image data is added, and a restriction step for restricting image processing affecting the added copy-forgery-inhibited pattern image data when it is determined that the copy-forgery-inhibited pattern image data is added. And

  Furthermore, a computer-executable program for realizing the control method of the image forming apparatus and a storage medium for storing the program in a computer-readable form are provided.

  According to the present invention, for an image to which a background pattern is added, image processing that eliminates the background pattern effect cannot be set, or even when set, a background pattern can be guaranteed by giving priority to the background pattern effect. Become.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the embodiment described below, an area to be visualized on a copy obtained by copying a printed output having a copy-forgery-inhibited pattern image is referred to as a latent image portion or a foreground portion. An area that disappears on the copy or has a lower density than the density of the latent image portion on the copy is referred to as a background portion. Then, description will be made assuming that text information and image information are input as a latent image portion and these text information and image information are reproduced on a copy so that they can be recognized at a higher density than the background portion.

  However, the background pattern image in the present invention is not limited to this. For example, text information or image information is set as a background portion, and an area around the background portion is set as a latent image portion, so that text information and image information are expressed as white on a copy. It may be a form.

  Further, the present invention is not defined by the type of tint block image, its generation process, color, shape, size, or the like.

<Outline explanation of tint block image>
An outline of a method for generating a copy-forgery-inhibited pattern image will be described with reference to FIG.

  Reference numeral 2501 denotes an example in which symbols are developed as a bitmap. In addition, the patterns used for the foreground, background, and camouflage of the tint block image as indicated by 2502, 2503, and 2504 are respectively held and developed to an arbitrary size.

  Reference numeral 2510 denotes generation of a foreground image of a tint block. Reference numeral 2511 denotes a developed foreground pattern stored in a predetermined number of repetitions. Reference numeral 2512 is a developed version of the designated font. In order to match the image size of the foreground pattern 2511, a white image is added to the periphery. After the images of the foreground pattern 2511 and the font 2512 are generated, the foreground image 2513 is generated by combining both images. At this time, the synthesis process is performed so that the foreground pattern 2511 remains only in the character (symbol) portion of the font 2512.

  Reference numeral 2520 denotes generation of a background image of the background pattern. Reference numeral 2521 denotes a stored background pattern which is repeated on the memory by a predetermined number of times. Reference numeral 2522 denotes a developed font. In order to match the image size of the background pattern 2521, a white image is added to the periphery. After the images of the background pattern 2521 and the font 2522 are generated, both images are combined to generate a background image 2523. At this time, the composition processing is performed so that the background pattern 2521 remains only in the portion other than the characters of the font 2522.

  Reference numeral 2530 denotes a camouflage image, which is an image in which a camouflage pattern 2504 is developed. This image may not be generated by an instruction from the operation unit.

  After the image generation processing of the foreground image generation 2510 and the background image generation 2520 is completed, the foreground image 2513 and the background image 2523 are simply combined to generate an image 2550. When there is an instruction to generate the camouflage image 2530, the image 2550 is further combined to generate an image 2560. At this time, composition is performed so that the camouflage image 2530 is outlined. This image 2560 becomes a tint block image.

  The tint block image 2560 is converted into a designated color and then combined with the document image 2540 to generate a tint block image 2570. Thereafter, the image is printed by printer image processing and then output by a printer.

  FIG. 25 and FIG. 26 show examples of concentrated foreground part patterns and dispersed dot background patterns, and examples of visualization of the foreground part patterns.

  FIG. 27 shows an example in which a fan is selected as a camouflage pattern in a tint block printed image.

  FIG. 28 is a diagram for explaining embossing / outlining. In the case of the embossing setting, a tint block image is generated such that a portion of tint block information such as characters is visualized on a copy. At this time, the characters can be recognized on the copy in a state where the characters are raised. On the other hand, in the case of white setting, a copy-forgery-inhibited pattern image in which a portion other than the copy-forgery-inhibited pattern information is visualized on the copy is generated. At this time, characters and the like can be recognized on the copy in a whitened state.

  In the image forming process of this embodiment, when a background pattern is set, image processing that affects the background pattern such as density adjustment, hue / saturation adjustment, and color balance, and overlapping background pattern settings are limited.

<Example of Configuration of Image Processing System of Present Embodiment>
FIG. 1 is a block diagram illustrating the overall configuration of the image processing system of the present embodiment.

  An image forming apparatus 200 constituting the image processing system includes a scanner unit 1201 that is an image input device, a printer unit 1202 that is an image output device, a Controller_Unit 1203, and an operation unit 1204 that is a user interface. The scanner unit 1201, the printer unit 1202, and the operation unit 1204 are each connected to a Controller_Unit 1203, and the Controller_Unit 1203 can transmit via a network G 3 or G 4 fax such as a LAN 1205.

  In addition, other image forming apparatuses 220 and 230 having the same device configuration as the image forming apparatus 200 can be connected to the LAN 1205. Also, a personal computer (hereinafter referred to as PC) 240 is connected, and can send and receive files using FTP and SMB protocols, send and receive e-mails, and print images created on a PC. The image forming apparatuses 220 and 230 have scanner units 1206 and 1210, printer units 1207 and 1211, and operation units 1209 and 1213, respectively, which are connected to Controller_Units 1208 and 1212.

<Example of Configuration of Image Forming Apparatus of Present Embodiment>
FIG. 2 is a perspective view illustrating a configuration of the image forming apparatus according to the present exemplary embodiment.

  A scanner unit 1201, which is an image input device, illuminates an image on paper as a document, and scans a CCD line sensor (not shown), thereby converting it into an electrical signal as raster image data. The original sheet is set on the tray 1602 of the original feeder 1601, and the apparatus user instructs the start of reading from the operation unit 1204. In response to this instruction, the controller CPU 1301 gives an instruction to the scanner 1201, feeds original sheets one by one from the tray 1602 of the feeder 1601, and performs an original image reading operation.

  The printer unit 1202 that is an image output device is a part that converts raster image data into an image on paper. The method includes an electrophotographic method using a photosensitive drum or a photosensitive belt, an ink jet method in which ink is ejected from a micro nozzle array and an image is directly printed on a sheet, and any method may be used. Activation of the printing operation is started by an instruction from the controller CPU 1301. The printer unit 1202 has a plurality of paper feed stages so that different paper sizes or different paper orientations can be selected, and has paper cassettes 1603, 1604, and 1605 corresponding thereto. A paper discharge tray 1606 is a paper discharge tray for receiving the printed paper.

(Configuration example of Controller_Unit)
FIG. 3 is a block diagram illustrating a configuration example of Controller_Unit of the image forming apparatus according to the present exemplary embodiment.

  The Controller_Unit 1203 is connected to a color scanner 1201 that is an image input device and a color printer 1202 that is an image output device. On the other hand, it is a controller for inputting / outputting image information and device information by connecting to a LAN 1205 or a public line (WAN) 1351.

  The CPU 1301 is a controller that controls the entire system. A RAM 1302 is a system work memory for the operation of the CPU 1301 and also an image memory for temporarily storing image data. A ROM 1303 is a boot ROM, and stores a system boot program. An HDD 1304 is a hard disk drive and stores system software and image data.

  An operation unit I / F 1305 is an interface unit with an operation unit (UI) 1204 and outputs image data to be displayed on the operation unit 1204 to the operation unit 1204. Further, it plays a role of transmitting information input by the system user from the operation unit 1204 to the CPU 1301. A network 1307 is connected to the LAN 1205 and inputs and outputs information.

  A Modem 1350 is connected to the public line 1351 and inputs / outputs image information. Binary image rotation 1352 and binary image compression / decompression 1353 are for changing the direction of an image before transmitting a binary image in Modem 1350, or converting the image to a predetermined resolution or a resolution adapted to the partner's ability. It is. For compression and decompression, JBIG, MMR, MR, and MH are supported. The DMAC 1309 is a DMA controller, reads an image stored in the RAM 1302 without passing through the CPU 1301, and transfers the image to the ImageBus I / F 1311. Alternatively, the image from the image bus is written into the RAM 1302 without going through the CPU 1301. The above devices are connected to the system bus 1308.

  The ImageBus 1311 is an interface for controlling high-speed image input / output via the image bus 1310. The compressor 1312 is a compressor for JPEG compression in units of 32 pixels × 32 pixels before sending an image to the image bus 1310. A decompressor 1313 is a decompressor for decompressing an image sent via the image bus 1310. A raster image processor (RIP) 1318 receives the PDL code from the host computer via the network 1307, and the CPU 1301 stores it in the RAM 1302 through the system bus 1308.

  The CPU 1301 converts the PDL into an intermediate code, inputs it again to the RIP 1318 via the system bus 1308, and develops it into a bitmap image (multi-value). The scanner image processing 1314 performs various appropriate image processing (for example, correction, processing, and editing) on the color image and the black and white image from the scanner 1201 (multi-value). Similarly, the printer image processing 1316 performs binary multi-value conversion by decompression 1313 during printing when appropriate various image processing (for example, correction, processing, editing) is performed on the printer 1202, so that binary and multi-value output is performed. Is possible.

  The image conversion unit 1330 has various image conversion functions used when converting an image on the RAM and drawing it back into the RAM 1330 again. The rotator 1319 can rotate an image in units of 32 pixels × 32 pixels by a specified angle, and supports binary and multi-value input / output. The magnification changer 1320 has a function (for example, from 25% to 400%) for converting the resolution of the image (for example, 600 dpi to 200 dpi) or for changing the magnification. Before scaling, the image of 32 × 32 pixels is rearranged into an image in units of 32 lines. The color space conversion 1321 converts, for example, a YUV image on the memory into a Lab image by matrix operation and LUT from the multi-valued input image, and stores it on the memory. Further, this color space conversion has a 3 × 8 matrix operation and a one-dimensional LUT, and can perform well-known background removal and show-through prevention. The converted image is output in multiple values. The binary multi-value conversion 1322 converts a 1-bit binary image into multi-value 8 bits and 256 gradations. On the other hand, the multi-value binary conversion 1325 converts, for example, an 8-bit, 256-gradation image on the memory into 1-bit, 2-gradation by a technique such as error diffusion processing, and stores it on the memory.

  The composition 1323 has a function of synthesizing two multi-valued image images (or binary images) on the memory into one multi-valued image (or binary image). For example, a company logo can be easily attached to a document image by combining the image of the company logo in the memory with the document image. The method of synthesis is averaged for each pixel, the value of the brighter pixel at the luminance level is the value of the pixel after synthesis, the darker is the pixel after synthesis, logical OR operation, logical product operation for each bit, A known technique such as performing an exclusive OR operation is used. The thinning 1324 is a unit that performs resolution conversion by thinning out pixels of a multi-valued image, and can output 1/2, 1/4, and 1/8 multi-valued images. By using it together with the zoom 1320, a wider range of enlargement and reduction can be performed. The move 1325 can output the input binary image or multi-valued image by adding a margin portion or deleting the margin portion. The rotation 1319, scaling 1320, color space conversion 1321, binary multi-value 1322, composition 1323, thinning 1324, movement 1325, and multi-value binary 1326 can be connected to operate. For example, when image rotation and resolution conversion are performed on a multi-valued image on a memory, both processes can be performed without using a memory.

(Configuration Example of Scanner Image Processing 1314)
FIG. 4 shows a detailed configuration example of the scanner image processing 1314 of the present embodiment.

  The RGB 8-bit luminance signals input from the scanner 1201 are converted into standard RGB color signals independent of the CCD filter color by masking 1401. In the filter 1402, for example, a 9 × 9 matrix is used, and an image is blurred and sharpened. A histogram 1403 is a processing unit that samples image signal data in an input image, and is used to determine the background level of the input image. In this module, RGB data in a rectangular area surrounded by the specified start and end points in the main and sub-scan directions is sampled at a constant pitch in the main and sub-scan directions, and a histogram is created. . This histogram is read when background skipping or prevention of show-through is specified, and the background of the original is estimated from the histogram, and is stored and managed in the memory or HDD along with the image as the background skipping level. Used for image processing. In gamma 1404, processing is performed so that the density of the entire image is increased or decreased. For example, it is a part that converts the color space of the input image into an arbitrary color space and performs correction processing related to the color of the input system.

  In order to determine whether the document is color or black and white, the image signal before scaling is converted into a known Lab by color space conversion 1405. Of these, a and b represent color signal components, and a 1-bit determination signal is output from the comparator 1406 as a chromatic color if it is equal to or higher than a predetermined level in the comparator 1406, and as an achromatic color otherwise. The counter 1407 measures the output from the comparator.

  The character / photo determination 1408 is a function for extracting a character edge from an image and separating the image into a character and a photo. As an output, a character photograph determination signal is obtained. This signal is also stored in the memory or HD together with the image and used during printing.

  The specific original determination unit 1409 can compare to what extent the input image signal matches the pattern held in the determination unit, and can read the determination result of coincidence or mismatch. The image is processed according to the determination result to prevent counterfeiting of banknotes and securities.

(Configuration Example of Printer Image Processing 1316)
FIG. 5 shows a detailed configuration example of the printer image processing 1316 of this embodiment.

  A hue / saturation adjustment 1500 adjusts the hue and saturation of an image. The background removal 1501 skips the background color of the image data and removes unnecessary background fogging. For example, the background removal is performed by a 3 × 8 matrix operation or a one-dimensional LUT. The monochrome generation 1502 is a monochrome generation unit that converts color image data, for example, RGB data into Gray single color when color image data is converted into monochrome data and printed as a single color. For example, it is composed of a 1 × 3 matrix operation that multiplies RGB by an arbitrary constant to obtain a Gray signal. The output color correction 1503 is an output color correction unit that performs color correction in accordance with the characteristics of the printer unit that outputs image data. For example, it includes processing by 4 × 8 matrix calculation or direct mapping.

  The filter processing 1504 is a filter processing unit that arbitrarily corrects the spatial frequency of the image data, and includes, for example, processing for performing a 9 × 9 matrix operation. The gamma correction 1505 is a process for performing gamma correction in accordance with the characteristics of the printer unit to be output, and is usually composed of a one-dimensional LUT. A halftone correction 1506 is a processing unit that performs arbitrary halftone processing in accordance with the number of gradations of the output printer unit, and is an intermediate that performs arbitrary screen processing such as binarization and binarization and error diffusion processing. Key processing unit. Each process can be switched by a character / photo determination signal (not shown). The inter-drum delay memory 1507 is a memory for superimposing CMYK images by shifting the CMYK printing timing by an amount between the drums in a color printer having CMYK drums. In a color printer having four drums for each color of CMYK, it can be delayed to align the position of the image.

(Configuration example of operation unit 1204)
FIG. 6 shows a configuration example of the operation unit 1204 of the present embodiment.

  The LCD display unit 1701 has a touch panel sheet 1702 pasted on the LCD, displays a system operation screen and soft keys, and transmits the position information to the controller CPU 1301 when the displayed keys are pressed. A start key 1704 is used when starting a document image reading operation. There is a green and red two-color LED 1704 in the center of the start key 1703, and the color indicates whether the start key 1703 is ready for use. A stop key 1705 serves to stop an operation in progress. An ID key 1706 is used when inputting the user ID of the user. A reset key 1707 is used when initializing settings from the operation unit.

<Example of Background Pattern Setting Operation in Image Forming Apparatus of this Embodiment>
Hereinafter, an example of setting a tint block for a copy image in the image forming apparatus according to the present embodiment will be described.

(Example of copy-forgery-inhibited pattern setting operation screen and operation procedure)
FIG. 7 shows a copy screen displayed on the operation unit 1204.

  Reference numeral 2601 denotes the state of the image forming apparatus, which indicates whether or not copying is possible, and the set number of copies is displayed at the same time. Reference numeral 2602 denotes a button for selecting whether to automatically remove the background for the image. Reference numeral 2603 denotes a slider capable of adjusting the density in nine steps. In 2604, a type of a document is selected, and text / photo / map, text, photographic paper photo, and printed photo can be selected. Reference numeral 2605 denotes an application mode button which can set various mode settings such as a reduced layout and a background pattern. Reference numeral 2606 denotes a button for performing settings related to various finishings, and shift sort, staple sort, and group sort can be set. Reference numeral 2607 denotes a button for performing settings relating to duplex reading and duplex printing.

  Next, a method for setting a background pattern in the application mode 2605 will be described.

  8, 9, 10, 11, 12, and 13 are display screens on which settings relating to copy-forgery-inhibited pattern image printing are performed. FIG. 14 is a flowchart of settings related to copy-forgery-inhibited pattern image printing.

  FIG. 8 shows a screen when the application mode button 2605 is pressed.

  As described above, when the application mode button is pressed, a button for setting a mode is displayed. That is, buttons such as a tint block 1801, a single color 1802, a mirror image 1803, a hue / saturation adjustment 1804, a color balance (fine adjustment of each color of CMYK) 1805, a negative / positive inversion 1806, a reduced layout 1807, and the like are displayed.

  In the case of setting a background pattern, the setting is performed by pressing a background pattern button 1801 (S2401). If other image processing such as the gamma correction 1505 or the hue / saturation adjustment 1500 is processed on the pattern of the tint block, the latent image may be easily visible at the time of printing, or the tint block may not appear at the time of grandchild copying. There is sex. For this reason, when the background pattern is set, it is necessary to prevent these processes from being performed. Therefore, first, it is checked whether density adjustment 2603, hue / saturation adjustment 1804, and color balance 1805 that are prohibited from being combined with the background pattern are set (S2402).

  If a combination prohibition item with a background pattern is set, an alarm is displayed to prompt the user that the background pattern cannot be set (S2406). If the combination is OK, the screen changes to a screen pattern setting screen (S2403).

  FIG. 9 shows a pressed background pattern setting screen.

  Here, information to be printed as a background pattern can be selected from a stamp 1901, a date 1902, and a machine number 1903. In addition to the present embodiment, for example, a number of copies or a user ID number may be selected. In addition, although any one is selected here, a plurality of pieces of information may be printed.

  FIG. 10 shows a screen when the stamp setting button 1901 is pressed.

  Here, the stamp to be printed as a copy-forgery-inhibited pattern is selected from six options: top secret, copy prohibition, invalid, CONFIDENTIAL, internal secret, and copy. For example, when the top secret 2001 is selected, after the button is pressed, the next key 2002 is pressed, and a transition is made to the next setting screen shown in FIG.

  FIG. 11 shows a screen when the date setting button 1902 is pressed.

  Here, the date format is selected from the four choices of YY / MM / DD, MM / DD / YY, DD / MM / YY, and YY / MM / DD. For example, if YY / MM / DD is selected, after the button 2101 is pressed, the next key 2102 is pressed to shift to the next setting screen shown in FIG.

  When the machine number setting button 1903 is pressed in FIG. 9, the screen changes to the next setting screen shown in FIG. As the copy-forgery-inhibited pattern information, the serial number of the machine body of each individual printer is printed.

  FIG. 12 shows a screen for setting items common to all copy-forgery-inhibited pattern information.

  On this screen, the font size and color to be printed as a background pattern are selected (S2404). The font size can be selected from large, medium, and small, and the color can be selected from black, magenta, cyan, user-specified color, and automatic. When the user-specified color is selected, the user inputs the specified color using RGB values or the like. If automatic is selected, a tint block image is generated in a color set in advance for each local pattern. After selecting the font size and color, the next key 2203 is pressed to shift to the next setting screen shown in FIG.

  FIG. 13 shows a screen subsequent to the common setting items.

  On this screen, you can select a camouflage pattern for tint block printing and set embossing / outline. The camouflage pattern is intended to make it difficult for human eyes to recognize that a copy-forgery-inhibited pattern image is added to a printed output to which a copy-forgery-inhibited pattern image is added. As shown in FIG. 13, the camouflage pattern can be selected from a plurality of patterns such as fans and cherry blossoms. There is also the option of not using a camouflage pattern.

  In the copy-forgery-inhibited pattern print image shown in FIG. 27 described above, the selected camouflage pattern is a fan.

  The embossed / outlined setting is used to designate which portion of the copy-forgery-inhibited pattern information such as text information or the other portion is visualized in the copied image. FIG. 28 described above is a diagram for explaining embossing / outlining.

  In the screen of FIG. 13, after selecting a camouflage pattern and embossed / outlined, press the OK key 2303 to confirm all settings related to the background pattern.

  If the background pattern is set first, the density adjustment 2603, the hue / saturation adjustment 1804, and the color balance 1805 which are prohibited from being combined in FIG. 7 and FIG. 8 are shaded so that they cannot be set. In addition, an alarm may be displayed when pressed to prompt the user that the combination is not possible (S2405).

  Thereafter, the document is set on the tray 1602 of the document feeder 1601, and when the apparatus user presses the start key 1703 of the operation unit 1204, the current reading is started. If the copy-forgery-inhibited pattern is set, the copy-forgery-inhibited pattern processing is performed on the image, the print processing is performed by the printer image processing 1316, and the image is output to the paper by the printer 1202.

(Example of tint block setting process in image forming apparatus)
An example of generating a tint block image in the image forming apparatus will be described in detail with reference to FIG.

  The image forming apparatus can expand characters and symbols designated by the operation unit 1204 as a bitmap on the RAM 1302. Reference numeral 2501 denotes an example in which symbols are expanded on the RAM 1302 as a bitmap. In addition, patterns used for the foreground, background, and camouflage of the copy-forgery-inhibited pattern image as shown in 2502, 2503, and 2504 are held in the HDD 1304, respectively, and can be expanded on the RAM 1302 to an arbitrary size.

  Reference numeral 2510 denotes generation of a foreground image of a tint block. Reference numeral 2511 denotes a foreground pattern stored in the HDD 1304 that is repeated a predetermined number of times and expanded in the RAM 1302. Reference numeral 2512 denotes a specified font developed in the RAM 1302. In order to match the image size of 2511, a white image is added to the periphery. After the images 2511 and 2512 are generated in the RAM 1302, both images are combined by the combining circuit 1323 to generate the foreground image 2513 in the RAM 1302. At this time, the composition processing is performed so that the pattern 2511 remains only in the character portion 2512.

  Reference numeral 2520 denotes generation of a background image of the background pattern. Reference numeral 2521 denotes a predetermined number of background patterns stored in the HDD 1304, which are expanded on the memory. Reference numeral 2522 represents a specified font developed in the RAM 1302. A white image is added to the periphery to match the image size of 2521. After generating images 2521 and 2522 in the RAM 1302, both images are combined by the combining circuit 1323 to generate a background image 2523 in the RAM 1302. At this time, the composition processing is performed so that the pattern of 2521 remains only in the portion other than the characters of 2522.

  Reference numeral 2530 denotes a camouflage image, which is an image obtained by developing a camouflage pattern 2504 in the RAM 1302. This image may not be generated by an instruction from the operation unit. After the image generation processing of 2510 and 2520 is completed, the foreground image 2513 and the background image 2523 are simply combined by the combining circuit 2023, and an image as indicated by 2550 is generated in the RAM 1302.

If there is an instruction to generate a camouflage image 2530, the image 2550 is further combined to generate an image such as 2560 in the RAM 1302. At this time, composition is performed so that the camouflage image is outlined. This image 2560 becomes a tint block image.
This tint block image 2560 is converted into a designated color and then combined with the original image 2540 to generate an image with a tint block as shown in 2570 in the RAM 1302. Thereafter, the image data is printed by the printer image processing 1316 via the image bus 1310 and then output by the printer 1202.

(Example of image processing restriction / prohibition when setting copy-forgery-inhibited pattern in image forming apparatus)
In step S2405 of FIG. 14, an example of image processing restriction / prohibition at the time of setting a background pattern is shown. In other words, the density adjustment 2603, the hue / saturation adjustment 1804, and the color balance 1805, which are combination prohibition items, are examples that are shaded so that they cannot be set or examples that display an alarm when pressed. On the other hand, when the background pattern is set by the image forming apparatus for image data received from the outside, density adjustment, hue / saturation adjustment, and color balance set in the image data may be limited as will be described later. Hereinafter, processing examples of these density adjustment, hue / saturation adjustment, and color balance restriction / prohibition will be described.

  Density adjustment is restricted / prohibited by gamma correction 1505 in FIG. That is, the gamma correction 1505 stores a default gamma correction value that allows image data to pass through without adjusting the density. If there is a background pattern setting and the density adjustment is restricted / prohibited, the default gamma correction value is stored. Use to process.

  Further, the restriction / prohibition of the hue / saturation adjustment is performed by the hue / saturation adjustment 1500 in FIG. Hue / saturation adjustment 1500 also stores default hue / saturation adjustment values that pass through the image data without hue / saturation adjustment, and there is a tint block setting to limit hue / saturation adjustment / When prohibiting, the default hue / saturation adjustment value is used for processing.

  Further, restriction / prohibition of color balance is performed by output color correction 1503 in FIG. The output color correction 1503 converts RGB colors into YMCK colors. In this example, with this output color correction 1503, conversion parameters for converting the input of R = 0, G = 255, B = 255 into colors of Y = 0, M = 0, C = 255, K = 0 are set. When there is a copy-forgery-inhibited pattern setting and color balance is restricted / prohibited, processing is performed using this conversion parameter.

  When the copy-forgery-inhibited pattern setting is made and image processing is restricted / prohibited, the printer image processing 1316 performs the above-described processing.

<Configuration example of PC of this embodiment>
FIG. 17 is a block diagram illustrating a hardware configuration of the PC 240 according to the present embodiment.

  In the figure, a PC 240 includes a CPU 101 that controls execution of document processing and printing processing based on a document processing program stored in a ROM for program in a ROM 103 or an external memory 111. Here, graphics, images, characters, tables (including spreadsheets), etc. are mixed in the document. The CPU 101 summarizes the control of each device connected to the system bus 104.

  In addition, the program ROM of the ROM 103 or the external memory 111 stores an operating system program (hereinafter referred to as OS) that is a control program of the CPU 101. Further, the font ROM of the ROM 103 or the external memory 111 stores font data used for the document processing. Further, the data ROM of the ROM 103 or the external memory 111 stores various data used when performing the document processing or the like. The RAM 102 functions as a main memory, work area, and the like for the CPU 101.

  A keyboard controller (KBC) 105 controls key input from a keyboard 109 or a pointing device (not shown). A CRT controller (CRTC) 106 controls display by a CRT display (CRT) 110 including display of a tint block image. A disk controller (DKC) 107 controls access to the external memory 111 such as a hard disk (HD) or a floppy (registered trademark) disk (FD). The external memory 111 stores a boot program, various applications, font data, user files, editing files, a printer control command generation program (hereinafter referred to as a printer driver), and the like. A network interface controller (NIC) 108 is connected to the image forming apparatus 200 via the LAN 1205 and executes communication control processing.

  The CPU 101 opens various windows registered in advance based on commands instructed by a mouse cursor (not shown) on the CRT 110 and executes various data processing. When executing printing, the user can open a window related to print settings and set the print processing method for the printer driver, including printer settings and print mode selection.

  FIG. 18 is a diagram showing a software configuration for print processing in the PC 240 shown in FIG.

  The application 201, graphic engine 202, printer driver 203, and system spooler 204 exist as files saved in the external memory 111. These are program modules that are loaded into the RAM 102 and executed by the OS or a module that uses the module.

  Further, the application 201 and the printer driver 203 can be added to the HD of the external memory 111 via the FD of the external memory 111, a CD-ROM (not shown), or the LAN 1205. The application 201 stored in the external memory 111 is loaded into the RAM 102 and executed. When printing is performed from the application 201 to the image forming apparatus 200, output (rendering) is performed using the graphic engine 202 that is similarly loaded into the RAM 102 and can be executed.

  The graphic engine 202 loads the printer driver 203 prepared for each printing apparatus from the external memory 111 to the RAM 102, and sets the output of the application 201 in the printer driver 203. Further, the graphic engine 202 converts a GDI (Graphic Device Interface) function received from the application 201 into a DDI (Device Driver Interface) function and outputs it to the printer driver 203.

  Based on the DDI function received from the graphic engine 202, the printer driver 203 converts it into a control command that can be recognized by the printer, for example, PDL (Page DescRIPtion Language). The converted printer control command is output as print data to the printer 1202 via the system spooler 204 loaded into the RAM 102 by the OS.

  The software configuration of the present embodiment includes a tint block processing unit 205 in the printer driver 203. The copy-forgery-inhibited pattern processing unit 205 may be a built-in module of the printer driver 203, or a library module added by individual installation. In addition, the printer driver 203 performs processing such as drawing of a tint block image, which will be described later, by executing the tint block processing unit 205 regarding printing of the tint block image.

<Example of tint block setting operation in PC of this embodiment>
Hereinafter, a method of forming an image with a tint block on the PC 240 will be described with reference to FIGS.

(Screen pattern setting screen example)
FIG. 19 shows an example of an initial screen of the user interface related to the tint block print arranged in the printer driver 203. In this example, settings relating to copy-forgery-inhibited pattern printing can be performed on the property sheet 301 in the dialog.

  Reference numeral 302 denotes a check box for designating whether to perform copy-forgery-inhibited pattern printing (printing including a copy-forgery-inhibited pattern image, hereinafter the same) for a print job. The content specified in the check box 302 is stored in the external memory 111 as additional print information that holds print setting information related to print data (original data). Reference numeral 303 denotes style information for making it possible to designate a plurality of pieces of setting information for a tint block print with one identifier (style). The printer driver 203 can select a plurality of styles, and the relationship between each style and predetermined information related to the tint block print is registered in the registry. When the button 304 is pressed, a style editing dialog 401 shown in FIG. 20A is displayed. Reference numeral 305 denotes a calibration button for adjusting the tint block pattern. If the image has already been raised and visible during printing, the pattern of the latent image portion and the background portion can be adjusted by performing calibration.

  FIG. 20A is a diagram illustrating an example of a dialog for editing individual detailed settings of a tint block print.

  In the figure, reference numeral 401 denotes the entire tint block information editing dialog, and a result of a tint block image generated by individual tint block information described later is displayed for preview in the same area. Reference numeral 402 denotes an area for displaying a list of styles that can be selected in 303 of FIG. Further, by using buttons 403 and 404, a style can be newly added or deleted. Reference numeral 405 denotes an area in which the currently designated style name is displayed.

  Reference numeral 406 denotes a radio button for selecting the type of drawing object used for the copy-forgery-inhibited pattern printing. When the user selects “character string” in 406, the text object can be used. When the user selects “image”, image data represented by BMP or the like can be used.

  In FIG. 20A, since “character string” is selected, setting information relating to text objects indicated by reference numerals 407 to 409, etc. is displayed in the dialog 401 and can be edited. On the other hand, when “image” is selected in the area 406, the information 407 to 409 is not displayed, and instead, an image file name display 415 and a file selection dialog (not shown) shown in FIG. 20B are displayed. Button 416 is displayed.

  In the present embodiment, the types of drawing objects used for copy-forgery-inhibited pattern printing performed by the PC 240 are “character string” and “image”, and either one is selected. However, the type of drawing object is not limited to this. Further, a plurality of types of drawing objects may be used at the same time.

  Reference numeral 407 denotes an area for displaying and editing a character string used as a copy-forgery-inhibited pattern image. Reference numeral 408 denotes an area for displaying and editing font information of a character string. In the present embodiment, only the font name selection screen is used, but the typeface family information (bold, italic, etc.), decorative character information, etc. may be expanded to be selectable. Reference numeral 409 denotes an area for displaying and setting the font size of the character string used as the tint block pattern. In this embodiment, a format that can be designated in three stages of “large”, “medium”, and “small” is assumed, but a commonly used font size designation method such as direct input of the number of points may be adopted. .

  Reference numeral 410 denotes a radio button for setting the printing order of the tint block pattern and the document data. When “watermark printing” is designated by this radio button, the original pattern data is drawn after the background pattern is drawn. On the other hand, when “overlapping printing” is designated, the background pattern is drawn after drawing the document data. The drawing procedure will be described later.

  Reference numeral 411 denotes a radio button for designating the arrangement angle of the tint block pattern. In this embodiment, three types of selection, “upward to the right”, “downward to the right”, and “horizontal” are possible. However, the angle designation method may be expanded by providing a numerical value input area in which an angle can be arbitrarily designated, an intuitively designated slider bar, and the like.

  Reference numeral 412 denotes an area for displaying and specifying the color used for the tint block pattern (foreground pattern, background pattern). Reference numeral 413 denotes a check box for exchanging the foreground pattern and the background pattern. If the check box is not checked, a copy-forgery-inhibited pattern image that generates a foreground pattern on the copy is generated. That is, it indicates that the foreground pattern is set to be reproducible on the copy. On the other hand, if the check box 413 is not checked, a copy-forgery-inhibited pattern image is generated so that the background pattern is visualized on the copy. That is, it indicates that the background pattern is set to be reproducible on the copy. At this time, the text information and image information specified in the foreground pattern can be recognized on the copy in a whitened state.

  Reference numeral 414 denotes an area for designating a camouflage image for making it difficult for human eyes to recognize that the copy-forgery-inhibited pattern image is added to the printed output to which the copy-forgery-inhibited pattern image is added. The camouflage image can be selected from a plurality of patterns. An option of not using camouflage images is also provided.

(Configuration example of additional print information)
Next, with reference to FIG. 21, additional print information related to the copy-forgery-inhibited pattern print setting information described in FIG. 20 will be described. In the present embodiment, the additional print information described below is generated on the RAM 102 in accordance with the designation from the copy-forgery-inhibited pattern information editing dialog, and is stored in the external memory 111 as information constituting a physical page to be printed. Stored in the file. In addition to the above configuration, various forms can be adopted for storing the additional print information.

  In the figure, a field 501 stores a value indicating an object type (text format or image) to be drawn by the copy-forgery-inhibited pattern print, which is designated in the area 406 of FIG. The field 502 stores setting information for the drawing object designated by the information in the field 501 designated in the areas 407 to 409 in FIG. 20A or the information in the field 501 in FIG. When text is selected, a character string, font name, and size information are stored. When an image is selected, the location of an input image file is stored.

  The field 503 stores information for designating the printing order such as whether the background pattern is drawn first or later on the document data designated in the area 410 of FIG. .

  The field 504 stores the angle information for arranging the drawing object specified in the area 411 in FIG. The field 505 stores color information used for the tint block pattern (foreground pattern, background pattern) specified in the area 412 in FIG.

  The field 506 stores information about the foreground pattern and the background pattern specified by the check box 413 in FIG. The field 507 stores the camouflage image pattern additional information specified in the area 414 in FIG.

  A field 508 stores foreground pattern density information. The field 509 stores background pattern density information.

(Example procedure for creating copy-forgery-inhibited pattern image data)
FIG. 22 is a flowchart showing the flow of image data generation processing in a tint block print. This flowchart shows the flow of image data generation processing corresponding to “watermark printing” described in FIG. Further, these processes are performed in a printing process using a general printer driver. The following processing is performed by the CPU 101 that controls and executes printing processing.

  Here, the case of “watermark printing”, that is, a case of drawing a tint block pattern before drawing of document data will be described with reference to the flowchart of FIG.

  In step 601, the CPU 101 draws a background pattern according to the information on the background pattern indicated by the background pattern information shown in FIG. The detailed processing will be described later with reference to FIG.

  Next, the drawing process of document data is started. First, in step 602, the CPU 101 initializes a counter that counts the number of logical pages per physical page (one side of the printing paper).

  In step 603, the CPU 101 determines whether the counter has reached a preset number of logical pages per physical page. If the determination result is not equal to the number of logical pages, the process proceeds to step 604.

  Next, in step 604, the CPU 101 increments the counter by one. Subsequently, in step 605, the CPU 101 calculates an effective print area for a logical page to be drawn based on the number of logical pages per page and the counter value. Next, in step 406, the CPU 101 reads the current logical page number from the print setting information (not shown) regarding the physical page using the counter value as an index. Then, the CPU 101 draws the corresponding logical page in a reduced size so that it falls within the effective print area. Of course, there is no need to reduce the size when multiple logical page layout printing is not designated. The above is the procedure of the drawing process related to “watermark printing”.

  The copy-forgery-inhibited pattern pattern dot data and the drawing data for one physical page created by the processing of FIG. 22 are transmitted from the PC 240 to the image forming apparatus via the LAN 1205 as a print job including information declaring that a copy-forgery-inhibited pattern is included in the job header. Are output by the image forming apparatus. Note that the background pattern processing of the image forming apparatus for a print job from the PC 240 will be described below with reference to FIGS. 15 and 16.

  FIG. 23 is a flowchart showing details of the tint block pattern drawing process of S601 shown in FIG. Hereinafter, the tint block pattern drawing process will be described with reference to FIG.

  First, a tint block pattern drawing process is started in step S701 via a user interface or the like. Next, in step S702, the CPU 101 acquires various types of information necessary for drawing a tint block pattern, such as an input background image, a background threshold pattern, a foreground threshold pattern, a foreground / background area designation image, and a camouflage area designation image. In step S703, the CPU 101 determines an initial pixel for generating a tint block pattern image. For example, when a tint block image is arranged by performing image processing on the entire input image from the upper left to the lower right in the raster scan order, the upper left pixel is set as the initial pixel.

In step S704, the CPU 1 arranges the background threshold pattern, the foreground threshold pattern, the foreground / background region designation image, and the camouflage image on the tile from the initial pixel of the input background image. And CPU101 performs the calculation based on the following formula | equation (1) with respect to the pixel of the input background image used as a process target. From the calculation result, the CPU 101 determines whether or not to write the pixel value corresponding to the dot at the time of printing in the memory area. The pixel value at this time corresponds to the input color information.
Here, the background threshold pattern and the foreground threshold pattern are pattern data including “1” and “0” corresponding to dot writing / non-writing. These pattern data are data patterned by respective dither matrices suitable for creating a foreground (latent image) and a background image.

nWriteDotOn =
nCamouflage × (nSmallDotOn × ¬nHiddenMark + nLargeDotOn × nHiddenMark) (1)
The definition of the components of this formula is shown below.
nComouflage: 0 in the camouflage area designating image, 0 if the target pixel is a pixel in the camouflage area, 1 otherwise.
nSmallDotOn: 1 if the pixel value of the background threshold pattern is black, 0 if it is white (color is not limited to this).
nLargeDotOn: 1 if the pixel value of the foreground threshold pattern is black, 0 if it is white (color is not limited to this).
nHiddenMark: 1 if the target pixel is a pixel corresponding to the latent image portion in the foreground / background region designation image, and 0 if the pixel corresponding to the background portion.
nHiddenMark: Denial of nHiddenMark. 0 in the foreground part and 1 in the background part.

  Note that it is not necessary to calculate using all the elements of Expression (1) for each processing target pixel. The processing can be speeded up by eliminating unnecessary calculations. For example, if nHiddenMark = 1, ¬nHiddenMark = 0, and if nHiddenMark = 0, ¬nHiddenmark = 1. Therefore, if nHiddenMark = 1, the value of the following equation (2) may be the value of nLargeDotOn, and if nHiddenMark = 0, the value of equation (2) may be the value of nSmallDotOn.

  Further, since the value of nCamouflage is an integration over the whole as shown in Expression (1), if nCamouflage = 0, nWriteDotOn = 0. Therefore, when nCamouflage = 0, the calculation of the following formula (2) can be omitted.

(NSmallDotOn × ¬nHiddenMark + nLargeDotOn × nHiddenMark) (2)
In the generated tint block image, an image having a size constituted by the least common multiple of the vertical and horizontal lengths of the background threshold pattern, the foreground threshold pattern, the foreground / background area designation image, and the camouflage area designation image is the smallest unit of repetition. It becomes. Therefore, the copy-forgery-inhibited pattern pattern drawing unit generates only a part of the copy-forgery-inhibited pattern image, which is the smallest unit of repetition, and repeatedly arranges the image in a tile shape so as to have the size of the image for generating a part of the copy-forgery-inhibited pattern image. As a result, the processing time required to generate the tint block image can be shortened.

  Next, in step S705, the CPU 101 determines the calculation result (value of nWriteDotOn) in step S704. That is, if nWriteDotOn = 1, the process proceeds to step S706, and if nWriteDotOn = 0, the process proceeds to step S707.

  In step S706, the CPU 101 performs processing for setting pixel values corresponding to dots at the time of printing. Here, the pixel value can be changed depending on the color of the tint block image. When it is desired to create a black background pattern, the processing target pixel of the background pattern image is set to black. In addition, a color copy-forgery-inhibited pattern image can also be created by setting cyan, magenta, and yellow according to the color of the toner or ink of the printer.

Further, when the image is image data of 1 to several bits per pixel, the pixel value can be expressed using the index color. The index color is a method for expressing image data. Specifically, color information that frequently appears in the target color image is set as a table of contents (for example, index 0 is white, index 1 is cyan, etc.), and the value of each pixel is the number of the table of contents describing the color information. (For example, the first pixel value is expressed as index 1 value, the second pixel value is expressed as index 2 value,...)
In step S707, the CPU 101 determines whether all the pixels in the processing target area have been processed. If all the pixels in the processing target area have not been processed, the process advances to step S2708 to select an unprocessed pixel, and the processes in steps S704 to 706 are executed again. If the processing for all the pixels in the processing target area is completed, the process proceeds to step S709.

  A tint block image can be generated by the above processing. It should be noted that this processing may cause a disadvantage that the effect of the forgery-preventing copy-forgery pattern is weakened due to the formation of dots in the foreground / background switching portion of the foreground / background area designation image and the outline of the foreground being conspicuous. Therefore, a process (boundary process) for preventing dot clumps from occurring in the foreground / background switching portion in the foreground / background area designation image may also be performed.

  In the process of step S601 in FIG. 22, since the copy-forgery-inhibited pattern image is the background, the watermark drawing process of step S710 is executed. A step S710 performs a process of drawing characters and the like created by application software after drawing the copy-forgery-inhibited pattern image (normal data after drawing the copy-forgery-inhibited pattern image). That is, no special processing is performed for drawing a tint block image.

  On the other hand, in the case of the superimposition process, since the copy-forgery-inhibited pattern pattern is drawn with the already drawn normal data as a background, the overdrawing process in step S711 is executed. In this case, since the tint block pattern is drawn on a character or the like created by application software, if the tint block pattern is simply drawn, the background is overwritten and cannot be seen. Therefore, it is avoided to completely overwrite by using logical drawing such as AND or OR. For example, when the underlying pixel is white (that is, the pixel value is zero), logical drawing such as drawing a pixel of the tint block pattern corresponding to the pixel is performed. Then, the process proceeds to step S712, and the drawing of the tint block image is finished.

<Example of PDL Data Processing in Image Forming Apparatus of This Embodiment>
FIG. 15 shows an example of a processing procedure of the image forming apparatus when the PDL data created by the PC is received.

(Example of PDL data processing without background pattern setting)
In the case of a PDL data development and storage job, the number of images, density, color / monochrome, single-sided / double-sided, etc. are set according to driver settings (not shown) of the PC 240, and PDL data is transferred via the LAN 1205. Received (S2701).

  Upon receiving a PDL_JOB request, the RIP 1318 performs RIP processing of the image and develops it in the memory (S2702), and then stores the image (including the character / photo determination signal) on the memory in the HDD 1304 (S2703). At this time, color / monochrome information, number of sheets, density, single-sided / double-sided, and PDL image, color space CMYK or RGB as image input sources are also stored in the SRAM (not shown) as image attribute information.

  When the PDL image is stored in the HDD 1304, this information is transmitted to the PC that has entered the PDL print.

  By setting the tint block for the PDL image in advance using the operation unit 1204 on the image forming apparatus side, it is also possible to add the tint block image to the PDL data and output it. . Therefore, at the time of outputting a PDL image, a determination process is performed to determine whether a background pattern is set in the image forming apparatus (S2704).

  If it is determined that the copy-forgery-inhibited pattern is not set in this determination processing, the image stored in the HDD is printed by the printer image processing 1316 and then output to the paper by the printer 1202 (S2708). If it is determined that the copy-forgery-inhibited pattern is set, it is necessary to determine whether or not an item that prohibits combination with a mode that affects the copy-forgery-inhibited pattern effect is set by the driver setting at the time of PDL output. Therefore, the attribute information of the PDL stored in the SRAM is referred to, and for example, it is determined whether or not the density is set (S2705).

  If the density is not set, the PDL image in the HDD is read out in the image forming apparatus and the tint block processing is performed (S2707). After the print processing is performed by the printer image processing 1316, the image is output to the paper by the printer 1202. . On the other hand, when the density is set, it is necessary to prioritize the background pattern as security information. Therefore, the density data is changed to a value that does not affect the background pattern image (S2706), and the background pattern is processed and output to the sheet. . The same applies to other hue / saturation adjustments and color balances. Such change of density data can be realized by the above-described method in the copy process, but is not limited to this.

(Processing example of PDL data with tint block setting)
As described above, in addition to the method of adding a background pattern in the image forming apparatus, it is also possible to add a background pattern on the PDL driver side of the PC 240 and output the PDL data as an image. The processing of the image forming apparatus in this case is shown below.

  By the way, there is a box function in the image forming apparatus, and there is a function that can store a scanned image or a PDL image in an HDD in the image forming apparatus and output it as needed.

  FIG. 16 is a box function display screen.

  In FIG. 16, reference numeral 3401 denotes each folder that logically partitions the HDD. Folder numbers are assigned to the folders in advance, and 3401 becomes the 0th folder. Next to the folder number, the percentage of disk space used by the folder is displayed. Folders can be given any name, and the name is displayed here. 3402 displays the usage amount of the entire HDD. At the time of output, an image to be output can be selected and printed. However, preset values such as the number of sheets and density can be changed and output.

  At this time, if an image with a tint block added on the PDL driver side is accumulated in the BOX, if the tint block image processing such as density change is performed, the tint block effect may be lost. For this reason, if processing such as density change, hue / saturation adjustment, and color balance is set during printing (Yes in S2711) for the image with the copy-forgery-inhibited pattern image added (Yes in S2710 in FIG. 15), an alarm is displayed. (S2712), prompting the user not to set. Then, the PDL image to which the background pattern is added is read out and printed by the printer image processing 1316 (S2713), and then output to the paper by the printer 1202.

  Whether or not a copy-forgery-inhibited pattern image is added to the image can be determined from the information set in the job header of the print job as described above. In this example, the copy-forgery-inhibited pattern image data is dot data, and document data Is assumed to be transmitted in PDL data.

  Note that the present invention may be applied to a system or an integrated apparatus constituted by a plurality of devices (for example, a host computer, an interface device, a printer, etc.) or an apparatus constituted by a single device.

  Another object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus. Needless to say, this can also be achieved by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. The functions of the above-described embodiments are not only realized by executing the program code read by the computer. This includes the case where the operating system (OS) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Needless to say.

  Further, the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU provided in the function expansion card or function expansion unit performs part or all of the actual processing. It goes without saying that the case where the functions of the above-described embodiments are realized by such processing is also included.

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

It is a figure which shows the example of whole structure of the image processing system of this embodiment. 1 is an external perspective view illustrating a configuration of an image forming apparatus according to an exemplary embodiment. It is a block diagram which shows the structural example of controller_Unit of this embodiment. FIG. 4 is a block diagram illustrating a configuration example of scanner image processing of FIG. 3. FIG. 4 is a block diagram illustrating a configuration example of printer image processing in FIG. 3. It is an external view which shows the structural example of the operation part of FIG. FIG. 4 is a diagram illustrating an example of a copy screen of the operation unit in FIG. 3. FIG. 4 is a diagram illustrating an example of a screen pattern setting screen of the operation unit in FIG. 3. FIG. 4 is a diagram illustrating an example of a screen pattern setting screen of the operation unit in FIG. 3. FIG. 4 is a diagram illustrating an example of a screen pattern setting screen of the operation unit in FIG. 3. FIG. 4 is a diagram illustrating an example of a screen pattern setting screen of the operation unit in FIG. 3. FIG. 4 is a diagram illustrating an example of a screen pattern setting screen of the operation unit in FIG. 3. FIG. 4 is a diagram illustrating an example of a screen pattern setting screen of the operation unit in FIG. 3. 5 is a flowchart illustrating an example of a tint block addition processing procedure at the time of copying in the image forming apparatus according to the present exemplary embodiment. 6 is a flowchart illustrating an example of a tint block addition processing procedure at the time of PDL reception of the image forming apparatus according to the present exemplary embodiment. 6 is a diagram illustrating an example of a display screen of an operation unit when a PDL is received by the image forming apparatus according to the present exemplary embodiment. FIG. It is a block diagram which shows the structural example of PC in this embodiment. It is a figure which shows the example of a software structure for the printing process in PC of FIG. It is a figure which shows an example of the initial screen of the user interface regarding the tint block of a PDL driver. It is a figure which shows an example of the dialog for editing each detailed setting with the tint block of a PDL driver. It is a conceptual diagram which shows the structure of the additional printing information regarding the setting information of copy-forgery-inhibited pattern printing. It is a flowchart which shows the example of an image data generation process procedure in the watermark printing of PC. 24 is a flowchart illustrating a detailed procedure example of a tint block pattern drawing process S601 in FIG. It is a figure explaining the generation method of the tint block image of this embodiment. It is a figure which shows the state of the dot in a tint block image. It is a figure which shows the state which a tint block image visualizes at the time of copying. It is a figure which shows the example of a production | generation of the tint block image which performed even the boundary process. It is a figure explaining the embossing / whitening of a tint block.

Claims (24)

An image forming apparatus for forming an image based on image data to which a copy-forgery-inhibited pattern image data representing a copy-forgery-inhibited pattern image to be visualized by copying is added,
Determining means for determining whether copy-forgery-inhibited pattern image data is added;
An image forming apparatus comprising: a restricting unit that restricts image processing affecting the added copy-forgery-inhibited pattern image data when it is determined that the copy-forgery-inhibited pattern image data is added. It further has an adding means for adding copy-forgery-inhibited pattern image data,
The image forming apparatus according to claim 1, wherein the determination unit determines whether or not the additional unit is operating.   The image forming apparatus according to claim 1, wherein the determination unit determines whether to add the copy-forgery-inhibited pattern image data in accordance with an instruction input for adding a copy-forgery-inhibited pattern from the operation unit.   The image forming apparatus according to claim 1, wherein the determination unit determines whether to add the copy-forgery-inhibited pattern image data according to the copy-forgery-inhibited pattern addition information included in the image data from the external device.   The image forming apparatus according to claim 4, wherein the image data from the external apparatus includes PDL data.   2. The restricting unit includes a prohibiting unit that prohibits setting of image processing affecting the added copy-forgery-inhibited pattern image data when the determination unit determines that the copy-forgery-inhibited pattern image data is added. The image forming apparatus described in 1.   The image forming apparatus according to claim 1, wherein the restricting unit includes a warning unit that issues a warning when image processing affecting the added copy-forgery-inhibited pattern image data is set.   8. The image processing according to claim 1, wherein the image processing that affects the added tint block image data includes at least one of density adjustment, hue adjustment, saturation adjustment, and color balance. Image forming apparatus.   9. The image forming apparatus according to claim 8, wherein the image processing that affects the added tint block image data further includes an overlapping tint block setting.   The restriction means restricts density adjustment by restriction of gamma correction means, restricts hue and saturation adjustment by restriction of hue / saturation adjustment means, and restricts color balance by restriction of output color correction means. The image forming apparatus according to claim 8.   11. The copy-forgery-inhibited pattern includes a latent image of an area that is visualized by copying and a background image that does not change by copying of an area excluding the latent image. The image forming apparatus described. A control method for an image forming apparatus for forming an image based on image data to which a copy-forgery-inhibited pattern image data representing a copy-forgery-inhibited pattern image is formed by copying,
A determination step of determining whether copy-forgery-inhibited pattern image data is added;
A control method for an image forming apparatus, comprising: a restricting step for restricting image processing affecting the added copy-forgery-inhibited pattern image data when it is determined that the copy-forgery-inhibited pattern image data is added. An additional step of adding the copy-forgery-inhibited pattern image data;
The method of controlling an image forming apparatus according to claim 12, wherein in the determination step, it is determined whether or not there is an operation in the addition step.   13. The method of controlling an image forming apparatus according to claim 12, wherein, in the determination step, it is determined whether or not to add a copy-forgery-inhibited pattern image data in accordance with an instruction input for adding a copy-forgery-inhibited pattern from an operation unit.   13. The method of controlling an image forming apparatus according to claim 12, wherein in the determination step, it is determined whether or not to add the copy-forgery-inhibited pattern image data according to the copy-forgery-inhibited pattern addition information included in the image data from the external device.   The image forming apparatus control method according to claim 15, wherein the image data from the external apparatus includes PDL data.   13. The restricting step includes a prohibiting step of prohibiting setting of image processing that affects the added copy-forgery-inhibited pattern image data when it is determined in the determination step that the copy-forgery-inhibited pattern image data is added. A method for controlling the image forming apparatus according to the above.   13. The method of controlling an image forming apparatus according to claim 12, wherein the restricting step includes a warning step of giving a warning when image processing affecting the added copy-forgery-inhibited pattern image data is set.   19. The image processing according to claim 12, wherein the image processing that affects the added tint block image data includes at least one of density adjustment, hue adjustment, saturation adjustment, and color balance. A method for controlling an image forming apparatus.   20. The method of controlling an image forming apparatus according to claim 19, wherein the image processing affecting the added tint block image data further includes overlapping tint block settings.   In the limiting step, density adjustment is limited by gamma correction means, hue and saturation adjustment is limited by hue / saturation adjustment means, and color balance is limited by output color correction means. The method of controlling an image forming apparatus according to claim 19.   The said copy-forgery-inhibited pattern includes a latent image in an area that is visualized by copying, and a background image that does not change by copying in an area excluding the latent image. A control method of the image forming apparatus described.   23. A computer-executable program for realizing the control method for an image forming apparatus according to claim 12.   A storage medium for storing the program according to claim 23 in a computer-readable form.

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