JP2013077961A - Image forming apparatus and printer driver program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of obtaining a recognizable output result desired by a user when outputting monochromatic image data that is converted from color image data.SOLUTION: The image forming apparatus converts color image data acquired via a scanner unit into monochromatic image data. It is determined whether or not, for two adjacent areas colored with different colors in a color image based on color image data, corresponding unrecognizable boundaries in a monochromatic image based on monochromatic image data are present. When the determination is affirmative, an operation panel is caused to display, as a preview, alternate image data in which the concentrations of two adjacent areas in the monochromatic image are made different. Then, any item of the alternate image data, selected by a user, is output. Alternatively, when the determination is negative, a monochromatic image based on the monochromatic image data is output.

Description

  The present invention relates to an image forming apparatus and a printer driver program, and more particularly to an image forming apparatus and a printer driver program that convert color image data into monochrome image data and output the monochrome image data.

  Along with the transition from monochrome to color, image forming apparatuses represented by MFPs (Multifunction Peripherals) and printers are also being replaced from monochrome machines to color machines.

  In recent years, color machines are in a state of reversing monochrome machines at a prevalence rate. Accordingly, the output cost difference (printing cost difference) between the color machine and the monochrome machine is becoming smaller than the conventional one. Therefore, when a document to be output (printed) is a color document including a color image, the document is often output (printed) in color.

  However, although the output cost difference between the color machine and the monochrome machine is getting smaller, the output cost is still smaller for the monochrome machine. As the number of output sheets increases, the cost difference also increases. Therefore, there are many companies and users who restrict or prohibit color output from the viewpoint of cost saving and ecology. In addition, due to the recent economic recession, such companies and users tend to increase. In such users, data is created and viewed in a color mode (color display), but printing is performed in a monochrome mode (monochrome output).

  On the other hand, conversion from color image data to monochrome image data at the time of printing is only color processing for converting RGB information (R: red, G: green, B: blue) into grayscale information. In some cases, it is difficult to identify an area printed in (a printed document). For example, if the color image data has multiple areas and each area is colored with a different color, printing the color image data as a monochrome image displays each area only with a difference in brightness, not a difference in color. Therefore, if the density difference between adjacent areas is small, there is a disadvantage that it becomes difficult to distinguish the boundary between adjacent areas.

  In order to solve such an inconvenience, Japanese Patent Application Laid-Open No. 2005-228620 proposes an image adjustment device that rewrites the density of one area so that the density difference is equal to or greater than a predetermined value with respect to adjacent areas. In the image adjustment apparatus of Patent Document 1, with the above configuration, even when printing is performed after converting color image data to monochrome image data, the boundary between adjacent regions can be identified. Hard copy).

JP 2008-67124 A

  However, in the above-mentioned Patent Document 1, although a printed material in which each adjacent area can be identified is obtained, the appearance of the printed material is different for each user, and there is a preference for each user. May not be printed.

  The present invention has been made in order to solve the above-described problems, and one object of the present invention is to provide an identification intended by a user when converting color image data to monochrome image data and outputting it. An image forming apparatus and a printer driver program capable of obtaining possible output results are provided.

  To achieve the above object, an image forming apparatus according to a first aspect of the present invention is represented by a display device, conversion means for converting inputted color image data into monochrome image data, and color image data. Whether or not there is a monochrome image represented by monochrome image data whose boundary between each other is indistinguishable. A generating unit for generating a plurality of alternative image data obtained by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern when the determination by the determining unit is affirmative Preview display means for causing the display device to display a plurality of alternative image data generated by the means as preview information; A first selection unit for causing the user to select one of a plurality of alternative image data displayed on the display device by the review display unit, and an image based on the monochrome image data when the determination by the determination unit is negative. When the determination by is affirmative, it includes output means for outputting the substitute image data selected by the user using the selection means. Note that the combination of the density conversion patterns of the two areas when the generation unit generates a plurality of alternative images differs for each alternative image.

  In the first aspect, as described above, when the determination by the determination unit is affirmative, a plurality of alternative image data is generated by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern. Since the plurality of generated substitute image data are displayed as preview information on the display device, the user can select desired substitute image data from the displayed substitute image data. When the determination by the determination unit is negative, an image based on the monochrome image data is output, and when the determination by the determination unit is affirmative, the alternative image data selected by the user is output. Therefore, an output result close to the image intended by the user can be obtained. That is, it is possible to obtain an identifiable output result intended by the user. In addition, by displaying a plurality of alternative image data obtained by converting the densities of two regions in monochrome image data in accordance with a predetermined conversion pattern, it is possible to propose an easy-to-see output result, so that the readability of the obtained output result is improved. You can also.

  Preferably, the preview display means includes means for causing the display device to display a preview image of the plurality of alternative image data generated by the generation means and a preview image of a monochrome image as preview information. Thereby, the user can check the monochrome image data converted by the preview image of the displayed monochrome image.

  More preferably, in response to a positive determination by the determination means, a second selection means for causing the user to select whether to output a monochrome image as it is or to generate alternative image data by the generation means. Further, the output means includes a monochrome image when the determination by the determination means is negative, and when the determination by the determination means is affirmative and the user selects to print a monochrome image by the second selection means. When an image based on the data is output, the determination by the determination means is affirmative, and the generation of alternative image data by the second selection means is selected, the user selects using the first selection means Means for outputting the substituted image data respectively. Thereby, an output result close to the image intended by the user can be easily obtained.

  More preferably, the color image data may represent a color image of a plurality of pages, and the determination means includes, for each of the color images of one page or a plurality of pages represented by the color image data, Page-specific determination means for determining whether or not there are two adjacent areas colored in different colors and in which a monochrome image represented by monochrome image data cannot be distinguished from each other The generation means includes a plurality of color images obtained by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern when the determination by the determination means is affirmative for each of one or more pages of color images. Including page-by-page generation means for generating alternative image data, and the preview display means includes one or more pages. For each of the over-di color image, when the determination by the determining means positive, including a page by preview display means for displaying on the display device a plurality of alternative image data generated by the generation means as the preview information. As a result, the user can select desired alternative image data from the alternative image data displayed as the preview information, so that the user can easily obtain an identifiable output result.

  More preferably, the color image data may represent a color image of a plurality of pages, and the determination means includes, for each of the color images of one page or a plurality of pages represented by the color image data, It is determined whether or not there are two adjacent areas colored in different colors and the boundary between the monochrome images represented by the monochrome image data cannot be identified, and the number is counted. The image forming apparatus further includes notification means for notifying the user of the counting result in response to the counting result by the page determining means being non-zero. Thereby, the user can instantly recognize that there is a monochrome image whose boundary cannot be identified, so that the output of such monochrome image data can be suppressed. For this reason, unnecessary output results (for example, unnecessary printing) can be reduced by stopping output of monochrome image data whose boundaries cannot be identified as they are.

  More preferably, it further includes additional generation means for additionally generating grayscale display alternative image data different from the plurality of alternative image data in response to a user instruction, and the preview display means is generated by the additional generation means The alternative image additional display for causing the display device to display the preview image of the alternative image data with different grayscale display, the preview image of the plurality of alternative image data generated by the generation unit, and the preview image of the monochrome image as preview information Including means. Thereby, when the substitute image of the image intended by the user is not included in the displayed substitute image data, the substitute image data to be displayed as preview information can be added, so that an output result closer to the image intended by the user can be obtained. can get.

  In this case, preferably, the color image data represents a color image of a plurality of pages, and the image forming apparatus further displays a preview image of the plurality of monochrome image data converted by the conversion unit on the display device as preview information. The plurality of image display means, and a second selection means for allowing the user to select one of the plurality of monochrome images displayed by the plurality of image display means, and the additional generation means includes: The monochrome image selected by the second selection means includes means for generating alternative image data of grayscale display different from the plurality of alternative image data, and the alternative image additional display means is the second selection means. A preview image of alternative image data generated for a monochrome image by a plurality of alternative images generated by the generation means Preview image data, and a preview image of a monochrome image, comprising means for displaying on the display device as preview information. As a result, alternative image data to be displayed as preview information can be added to a desired page (selected page), so that an output result closer to the image intended by the user can be obtained. Further, since the substitute image data is not added to a page that does not require addition of substitute image data, the user can easily select the displayed substitute image data.

  Preferably, a display unit for displaying a monochrome image of the monochrome image data converted by the conversion unit on the display device, and a region designated by the user among the regions of the monochrome image displayed by the display unit are generated. And additional generation means for additionally generating alternative image data that has been changed to a shade display different from the alternative image of the alternative image data generated by the preview image data, and the preview display means includes the alternative image generated by the additional generation means Means for displaying a preview image of the data on the display device is included. Thereby, alternative image data in which a desired region in the monochrome image data is displayed in a different shade (different pattern) is obtained. For this reason, the output result closer to the image intended by the user can be obtained.

  An image forming apparatus according to a second aspect of the present invention is different from each other in a display device, conversion means for converting input color image data into monochrome image data, and a color image represented by the color image data. In order to make the user determine whether or not there are two adjacent areas colored with colors and the monochrome image represented by the monochrome image data cannot be distinguished from each other by the conversion means. First preview display means for displaying the preview image of the converted monochrome image on the display device as preview information, and in response to a user instruction, the densities of the two regions in the monochrome image data are each in accordance with a predetermined conversion pattern. A generating means for generating a plurality of converted alternative image data, and a copy generated by the generating means; The second preview display means for displaying the alternative image data as preview information on the display device, and the user for selecting one of the plurality of alternative image data displayed on the display device by the second preview display means. And a process for outputting an image based on monochrome image data in response to a user's selection by the selection means, and a process for outputting alternative image data selected by the user using the selection means. Output means for executing.

  In the second aspect, as described above, the monochrome image of the converted monochrome image data is displayed on the display device so that the user can determine whether or not there is a monochrome image whose boundary cannot be identified. Display a preview image of the data. The user can confirm whether or not there is monochrome image data whose boundary cannot be identified by referring to the displayed preview image. When the user's determination is affirmative (when the user determines that there is monochrome image data whose boundary cannot be identified), in response to the user's instruction, the respective densities of the two regions in the monochrome image data are respectively converted to predetermined values. A preview image of a plurality of alternative image data converted according to the pattern is displayed on the display device. The user can select desired substitute image data from the displayed substitute image data. When the determination by the user is negative, an image based on the monochrome image data is output. When the determination by the user is affirmative, the alternative image data selected by the user is output. Therefore, an output result close to the image intended by the user can be obtained. That is, it is possible to obtain an identifiable output result intended by the user. In addition, by displaying a plurality of alternative image data obtained by converting the densities of two regions in monochrome image data in accordance with a predetermined conversion pattern, it is possible to propose an easy-to-see output result, so that the readability of the obtained output result is improved. You can also.

  A printer driver program according to a third aspect of the present invention provides a computer connected to a display device, a conversion means for converting input color image data into monochrome image data, and a color image represented by the color image data. A determination for determining whether there are two adjacent areas colored in different colors in the monochrome image represented by the monochrome image data, the boundaries of which cannot be distinguished from each other And means for generating a plurality of alternative image data obtained by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern when the determination by the determination means is affirmative, and generated by the generation means To display a plurality of substitute image data as preview information on the display device Display means, first selection means for causing the user to select one of a plurality of alternative image data displayed on the display device by the preview display means, and an image based on the monochrome image data when the determination by the determination means is negative When the determination by the determination means is affirmative, the substitute image data selected by the user using the selection means is caused to function as output means for outputting each.

  In the third aspect, as described above, when the determination by the determination unit is affirmative, a plurality of alternative image data in which the densities of the two regions in the monochrome image data are respectively converted according to a predetermined conversion pattern is generated. Since the plurality of generated substitute image data are displayed as preview information on the display device, the user can select desired substitute image data from the displayed substitute image data. When the determination by the determination unit is negative, an image based on the monochrome image data is output, and when the determination by the determination unit is affirmative, the alternative image data selected by the user is output. Therefore, an output result close to the image intended by the user can be obtained. That is, it is possible to obtain an identifiable output result intended by the user. In addition, by displaying a plurality of alternative image data obtained by converting the densities of two regions in monochrome image data in accordance with a predetermined conversion pattern, it is possible to propose an easy-to-see output result, so that the readability of the obtained output result is improved. You can also.

  Preferably, the preview display means includes means for causing the display device to display a preview image of the plurality of alternative image data generated by the generation means and a preview image of a monochrome image as preview information.

  More preferably, in response to the determination by the determination unit being affirmative, the computer causes the user to select whether to output a monochrome image as it is or to generate alternative image data by the generation unit. Further functioning as a selection means, the output means is selected by the user to print a monochrome image by the second selection means when the determination by the determination means is negative and when the determination by the determination means is affirmative. If the determination means outputs an image based on the monochrome image data and the determination by the determination means is affirmative, and the generation of alternative image data by the second selection means is selected, the first selection means is used. Means for outputting the substitute image data selected by the user.

  More preferably, the color image data may represent a color image of a plurality of pages, and the determination means includes, for each of the color images of one page or a plurality of pages represented by the color image data, Page-specific determination means for determining whether or not there are two adjacent areas colored in different colors and in which a monochrome image represented by monochrome image data cannot be distinguished from each other The generation means includes a plurality of color images obtained by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern when the determination by the determination means is affirmative for each of one or more pages of color images. Including page-by-page generation means for generating alternative image data, and the preview display means includes one or more pages. For each of the over-di color image, when the determination by the determining means positive, including a page by preview display means for displaying on the display device a plurality of alternative image data generated by the generation means as the preview information.

  More preferably, the color image data may represent a color image of a plurality of pages, and the determination means includes, for each of the color images of one page or a plurality of pages represented by the color image data, It is determined whether or not there are two adjacent areas colored in different colors and the boundary between the monochrome images represented by the monochrome image data cannot be identified, and the number is counted. The printer driver program further causes the computer to function as notifying means for notifying the user of the counting result in response to the counting result by the page determining means being non-zero.

  More preferably, in response to a user instruction, the computer further functions as an additional generation means for additionally generating alternative image data of grayscale display different from the plurality of alternative image data, and the preview display means is added A display device for displaying a preview image of alternative image data of different gray levels generated by the generation unit, a preview image of a plurality of alternative image data generated by the generation unit, and a preview image of a monochrome image as preview information. Alternative image addition display means is included.

  In this case, preferably, the color image data represents a plurality of pages of color images, and the computer displays a plurality of images for causing the display device to display preview images of the plurality of monochrome image data converted by the conversion unit as preview information. It further functions as a second selection unit for allowing the user to select any one of the display unit and the plurality of monochrome images displayed by the multiple image display unit, and the additional generation unit includes a second of the plurality of monochrome images. And a means for generating alternative image data of grayscale display different from the plurality of alternative image data, and the alternative image additional display means for the monochrome image by the second selection means. A preview image of the substitute image data generated by the above, a plurality of substitute image data generated by the generating means Data of the preview image, and a preview image of a monochrome image, comprising means for displaying on the display device as preview information.

  Preferably, the computer displays a monochrome image of the monochrome image data converted by the conversion unit on the display device, and an area designated by the user among the monochrome image areas displayed by the display means. The substitute image data generated by the generation unit is further functioned as an additional generation unit for additionally generating alternative image data changed to a grayscale display different from the alternative image, and the preview display unit is generated by the additional generation unit. Means for causing the display device to display a preview image of the alternative image data.

  A printer driver program according to a fourth aspect of the present invention provides a computer connected to a display device, a converting means for converting input color image data into monochrome image data, and a color image represented by the color image data. In order to make the user determine whether there are two adjacent areas colored in different colors from each other and in which a monochrome image represented by the monochrome image data cannot be distinguished from each other In addition, the first preview display means for displaying the preview image of the monochrome image converted by the conversion means on the display device as preview information, and the densities of the two regions in the monochrome image data are respectively determined in response to a user instruction. To generate multiple alternative image data converted according to the conversion pattern of Means, a second preview display means for causing the display device to display a plurality of substitute image data generated by the generating means, and a plurality of substitute images displayed on the display device by the second preview display means Selection means for causing the user to select any of the data, processing for outputting an image based on the monochrome image data in response to the user's selection by the selection means, and an alternative image selected by the user using the selection means It functions as an output means for selectively executing the process of outputting data.

  As described above, according to the present invention, an image forming apparatus and a printer driver program capable of obtaining an identifiable output result intended by a user when color image data is converted into monochrome image data and output. Can be easily obtained.

1 is a block diagram showing a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a perspective view which shows the external appearance of the image forming apparatus shown in FIG. FIG. 2 is an enlarged plan view showing an operation panel portion of the image forming apparatus shown in FIG. 1. 3 is a flowchart showing a control structure of color / monochrome conversion copy processing according to the first embodiment of the present invention. FIG. 5 is a diagram showing a configuration of a screen displayed on an operation panel in step S312 shown in FIG. FIG. 5 is a diagram showing a configuration of a screen displayed on an operation panel in step S314 shown in FIG. FIG. 5 is a diagram showing a configuration of a screen displayed on an operation panel in step S316 shown in FIG. It is a detailed flow of step S302 shown in FIG. It is a figure which shows the image from which the boundary of an adjacent area | region becomes difficult to identify when color image data is converted into monochrome image data. It is a detailed flow of step S308 shown in FIG. FIG. 11 is a diagram showing a configuration of a screen displayed on the operation panel in step S504 shown in FIG. 10. FIG. 11 is a diagram showing a configuration of a screen displayed on the operation panel in step S502 shown in FIG. 10. It is a detailed flow of step S316 shown in FIG. It is a figure for demonstrating the production | generation of alternative image data. It is a detailed flow of step S326 shown in FIG. It is a figure for demonstrating step S712 and step S714 shown in FIG. It is a flowchart which shows the control structure of the color / monochrome conversion copy process based on the 2nd Embodiment of this invention. It is a figure which shows the structure of the screen displayed on an operation panel in step S1300 shown in FIG. It is a figure which shows the connection with the image forming apparatus of the information processing apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the information processing apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the control structure of the color / monochrome conversion printing based on the 3rd Embodiment of this invention.

  In the following description and drawings, the same reference numerals and names are assigned to the same components. Their functions are also the same. Therefore, detailed description thereof will not be repeated.

(First embodiment)
<Hardware configuration>
[Image forming apparatus 100]
Referring to FIG. 1, an image forming apparatus 100 according to the present embodiment is a digital multi-function peripheral. The image forming apparatus 100 is connected to the information processing apparatus 200 via a network 30 including a LAN (Local Area Network) line. The image forming apparatus 100 and the information processing apparatus 200 can mutually transmit and receive various data including image data.

  The information processing apparatus 200 is a terminal device such as a PC (Personal Computer) that is operated by a general user in order to use the image forming apparatus 100. In the information processing apparatus 200, an application program such as a graphic drawing tool and a word processor, and a printer driver program (hereinafter simply referred to as “printer driver”) for realizing a print job of image data are installed. The information processing apparatus 200 creates image data for outputting an image including characters and graphics in accordance with an instruction from a user who uses the application program, and converts the created image data into a printer description language by a printer driver. Then, it can be transmitted to the image forming apparatus 100. Although only one information processing apparatus 200 is shown in FIG. 1, there may be a large number in practice.

  The image forming apparatus 100 forms an image on a recording sheet by an electrophotographic method. The image forming apparatus 100 includes a copy mode, a printer mode, and a scanner mode. The image forming apparatus 100 further has a function of acquiring color image data, converting the acquired color image data into monochrome image data (grayscale data), and outputting (printing) as a monochrome image.

  The image forming apparatus 100 includes a control unit 110, a scanner unit 120, an image processing unit 130, a printer unit 140, an operation panel 150, a NIC (Network Interface Card) 160, and a power supply control unit 170. Referring to FIGS. 1 and 2, image forming apparatus 100 further includes a paper discharge tray 180 and a paper discharge processing device 182.

  The control unit 110 is substantially a computer and includes a CPU 112, a ROM 114, a RAM 116, and an HDD 118. A BUS line 190 is connected to the CPU 112, and the ROM 114, the RAM 116, and the HDD 118 are electrically connected to the BUS line 190. The CPU 112 executes various computer programs in response to instructions from the operation panel 150 and the like, thereby executing desired processing such as operations of the respective units of the image forming apparatus 100 and communication with the information processing apparatus 200. The various computer programs described above are stored in advance in the ROM 114 or the HDD 118, and are read from the ROM 114 or the HDD 118 and transferred to the RAM 116 when desired processing is executed. The CPU 112 reads and interprets a program instruction from an address in the RAM 116 specified by a value stored in a register called a program counter (not shown) in the CPU 112. The CPU 112 also reads data necessary for the operation from the address specified by the read instruction, and executes an operation corresponding to the instruction on the data. The execution result is also stored in an address specified by the instruction, such as a register in the RAM 116, HDD 118, and CPU 112.

  The HDD 118 performs various processes such as a process for presenting an alternative image and a process for identifying a boundary in image data, which will be described later, together with a computer program for realizing general operations of the image forming apparatus 100. The computer program is stored. This computer program is provided from the information processing apparatus 200 via the network 30 and the NIC 160. This computer program may be provided by a recording medium such as a DVD on which the computer program is recorded. That is, a DVD as a computer program recording medium may be mounted on a DVD drive (not shown) built in image forming apparatus 100, and the computer program may be read from the DVD and installed in HDD 118. In addition, the HDD 118 stores various data including image data and the like.

  Further, the scanner unit 120, the printer unit 140, the image processing unit 130, the operation panel 150, the NIC 160, and the power supply control unit 170 are electrically connected to the BUS line 190.

  The scanner unit 120 acquires image data by reading image information of a document. When the original is a color original including a color image, the scanner unit 120 acquires color image data. The scanner unit 120 includes a document detection sensor and a CCD (Charge-Coupled Device) line sensor (none of which is shown). The document detection sensor is a reflection obtained by irradiating light from a light source (not shown) to an image surface of a document placed on a document placement table manually by a user or by an automatic document feeder. An optical image is formed on the CCD line sensor. The CCD line sensor sequentially photoelectrically converts the formed reflected light source and outputs it to the image processing unit 130 as image data. That is, the scanner unit 120 reads image information from a document placed on a document placement table by a document detection sensor during document copying and scanning, and converts the read image information into an electrical signal by a CCD line sensor. The data is output to the image processing unit 130 as data.

  When the original to be read is a color original, the scanner unit 120 performs various correction processes according to the scanner characteristics including, for example, shading correction on the image data input from the CCD line sensor, and performs RGB (R: Image data (hereinafter referred to as “RGB data”) in the format of red, G: green, and B: blue is created, and the created RGB data (color image data) is sequentially output to the image processing unit 130.

  The image processing unit 130 includes an MPU (Micro Processing Unit, not shown). The image processing unit 130 performs various processes including predetermined image processing such as rasterization processing on the image data received from the scanner unit 120 or the information processing apparatus 200 to generate print data with a predetermined gradation. Created and output to the printer unit 140.

  When the image data received from the scanner unit 120 or the information processing apparatus 200 is color image data, and the color image data is output (printed) as a monochrome image, the image processing unit 130 outputs the received color image data. The image data is converted into monochrome image data (grayscale image data), and the converted monochrome image data is output to the printer unit 140. Conversion from color image data to monochrome grayscale image data (Gray conversion) is performed by multiplying RGB information of the color image data by a predetermined coefficient.

  Here, when a color image of color image data has a plurality of regions separated by boundaries and is colored with different colors for each region, when the color image data is printed as a monochrome image, each region in the monochrome image is It is displayed only by the difference in brightness (density difference), not the difference in color. Therefore, when the density difference between adjacent regions is small, it becomes difficult to distinguish the boundary between adjacent regions.

  The image forming apparatus 100 according to the present embodiment determines whether or not the monochrome image of the converted monochrome image data is such monochrome image data in which the boundary between adjacent regions is difficult to distinguish. Specifically, the image processing unit 130 determines whether or not the boundary between adjacent regions in the converted monochrome image data can be identified (whether there is unidentifiable image data). 132. The boundary identification unit 132 performs region separation based on the color difference and density difference of the received color image data, and calculates the color difference and density difference between adjacent regions. The boundary identification unit 132 further includes a memory (not shown) in which threshold values for color difference and density difference between adjacent regions are stored in advance, and by comparing the calculated value with the threshold value, It is determined whether or not the boundary can be identified. When the calculated value is smaller than the threshold value (when the hue or density is close), it is determined that the boundary between adjacent regions is difficult to identify (not distinguishable), and the result is stored in the memory. If the calculated value is equal to or greater than the threshold value, it is determined that the boundary between adjacent regions can be identified, and the result is stored in the memory. To do. The threshold value can be set to a value at which the density difference between adjacent regions after conversion into monochrome image data (grayscale image data) is “64” (1/4 of 256 gradations).

  The image processing unit 130 further includes a substitute image generation unit 134. The substitute image generating unit 134 is a monochrome substitute image (substitute image data) in which the density of each region is changed so that the density difference between adjacent regions becomes larger than a preset (stored) threshold (for example, “64”). Are generated and stored. That is, according to a predetermined conversion pattern, a plurality of alternative image data in which the density of adjacent areas in the monochrome image data is made different is generated and stored. Specifically, when converting to monochrome image data, processing is performed to change the color of one area to be blacker or whiter so that a larger difference than a preset threshold value can be made between adjacent areas. (At this point, two alternative image patterns are generated). In addition, when the density difference between adjacent areas is smaller than the threshold value for other places (areas), similarly, processing is performed so that a difference larger than the threshold value can be made. Pattern (a plurality of alternative image data with different shading display) is generated and stored.

  The printer unit 140 includes an image memory 142 and a printing unit 144. The image memory 142 includes a RAM and temporarily stores print data in units of pages. The image memory 142 temporarily stores, for example, print data input from the image processing unit 130 for transmission to the printing unit 144 in response to an instruction from the control unit 110 or the like, and stores the stored print data. Data is output to the printing unit 144 in synchronization with image formation by the printing unit 144.

  The printing unit 144 is detachably attached to the photosensitive drum, the charger, the LSU (Laser, Scanning Unit), the developing device, the transfer device, the cleaning device, the fixing device (none of which is shown), and the image forming apparatus 100. Including a toner cartridge to be mounted on. The printing unit 144 further includes a manual paper feed tray (not shown), a first paper feed tray 186, and a second paper feed tray 188 that are detachably attached to the image forming apparatus 100. These paper feed trays are installed so as to be lined up and down in this order, hold the recording paper, and feed the recording paper to a paper transport unit (not shown). The manual paper feed tray is a tray on which a user manually installs desired recording paper. The first paper feeding tray 186 and the second paper feeding tray 188 are trays for holding recording papers of different sizes. It is. In response to an instruction from the control unit 110 or the like, the printing unit 144 is an image based on print data transmitted from the image memory 142 onto a recording sheet conveyed from one of the paper feed trays via the sheet conveyance unit. To print.

  The printed recording paper is guided toward the paper discharge tray 180 or the paper discharge processing device 182 and discharged to the paper discharge tray 180 or is discharged to one of the paper discharge trays 184 of the paper discharge processing device 182. The

  In the paper discharge processing device 182, processing for sorting and discharging a plurality of recording papers to each paper discharge tray 184, processing for punching each recording paper, and processing for stapling each recording paper are performed. For example, when a plurality of printed materials are created, each recording sheet is sorted and discharged to each paper discharge tray 184 so that a part of the printed material is allocated to each paper discharge tray 184. In addition, a punching process or a stapling process is performed on each recording sheet on the discharge tray 184 to create a printed matter.

  2 and 3, operation panel 150 includes a display output unit 152 formed of a liquid crystal display, and an operation interface unit formed of operation keys 154, touch panel 156, and the like. The display output unit 152 provides the user with various information such as information relating to the state of the image forming apparatus 100 and the state of various processes. The display output unit 152 includes a touch panel 156.

  The operation interface unit provides an interface for the user to operate the image forming apparatus 100. The operation panel 150 also provides an interactive operation interface to the user, which is configured by overlapping a liquid crystal display and a touch panel 156. This interactive operation interface accepts a user instruction for the overall operation of the image forming apparatus 100 from the touch panel 156, displays the contents of the instruction on the liquid crystal display, and sends a control signal corresponding to the instruction to the control unit 110 or Output to the MPU or the like of the image processing unit 130. The operation panel 150 includes a power key for inputting a power-on instruction and a power-off instruction, a print start key 154a for starting a print job, and the like.

  The display output unit 152 of the operation panel 150 displays a preview image of monochrome image data converted from color image data. The display output unit 152 further displays a preview image of a plurality of alternative image data generated by the alternative image generation unit 134 (see FIG. 1).

  Referring to FIG. 1, NIC 160 interfaces with network 30. The image forming apparatus 100 can perform data communication with the information processing apparatus 200 on the network 30 via the NIC 160. The image forming apparatus 100 can receive a command signal for instructing execution of various processes such as a print job from the information processing apparatus 200 via the NIC 160.

  The power supply controller 170 is electrically connected to the external power supply 50. The power supply control unit 170 acquires power necessary for the operation of each unit of the image forming apparatus 100 from the external power supply 50 and supplies the acquired power to each unit of the image forming apparatus 100.

  The image forming apparatus 100 operates each of the above-described units so that a document image is read and printed on a recording sheet in response to an instruction by a user input operation from the operation panel 150 or an instruction from the information processing apparatus 200 or the like. Execute any one of various modes such as a printer mode for receiving image data transmitted from the information processing apparatus 200 or the like and printing it on a recording sheet, or a scanner mode for reading a document image and transmitting it to the information processing apparatus 200 or the like. To do.

<Software configuration>
[Image forming apparatus 100]
Image forming apparatus 100 according to the present embodiment determines whether or not the boundary between adjacent areas in a monochrome image can be identified when color image data is output as a monochrome image, and the boundary between adjacent areas is difficult to identify. If it is determined that, a process of proposing a plurality of alternative images is executed. Such processing is realized by software executed using the hardware configuration described above. In the following, this software configuration will be described using color / monochrome conversion copy as an example.

  Referring to FIG. 4, this program reads (scans) an original through scanner unit 120 to obtain color image data, and after step S300, the obtained color image data is converted into a monochrome image. Step S302 for executing a boundary identification process for identifying the boundary of adjacent areas in the monochrome image data converted at the time of conversion into data (grayscale image data), and the acquired color image data after step S302. Step S304 for converting to monochrome image data.

  Further, after step S304, the program determines whether or not the boundary between adjacent regions can be identified in the converted monochrome image data, and branches the control flow according to the determination result in steps S306 and S306. When it is determined that the boundary between adjacent areas cannot be identified, a notification is displayed on the liquid crystal display of the operation panel 150 to notify the user (warning), and the converted monochrome image data after step S308. In step S310, it is determined whether or not an instruction to display a preview on the liquid crystal display is issued by the user, and an instruction to preview the converted monochrome image data in step S310 is branched in step S310. If it is determined that the user has done this, It is determined whether or not a data preview display instruction has been issued by the user, and the flow of control is branched according to the determination result. In step S310, it is determined that the monochrome image data preview display instruction has not been issued by the user. If it is determined, and if it is determined in step S312 that the user has not issued a substitute image data preview display instruction, it is determined whether or not an instruction to execute printing has been issued by the user, and according to the determination result. Step S314 for branching the flow of control.

  Referring to FIG. 5, in step S <b> 312, a preview screen 250 for displaying a preview image of the converted monochrome image data (monochrome converted image) is displayed on the liquid crystal display of operation panel 150. FIG. 5 shows an example in which a plurality of originals (a plurality of pages) whose boundaries are difficult to identify are detected, and a plurality of monochrome image data corresponding to the originals are displayed as previews. The corresponding page number is assigned to the monochrome image data displayed in the preview. The preview screen 250 includes a slide bar 252 for sliding the screen, a “substitute image display” key 254 for previewing the substitute image for the selected document, and substitute images for all the displayed monochrome image data. A check box 256 operated to display a preview and a “cancel” key 258 for canceling the preview display are displayed. If there is only one document whose boundary is difficult to identify, only the corresponding monochrome image data is displayed as a preview.

  Referring to FIG. 6, when it is determined in step S310 that the user has not instructed to display monochrome image data, and in step S312, it is determined that the user has not received a preview display instruction for alternative image data. In this case (when the “cancel” key 258 shown in FIG. 5 is pressed by the user), an operation screen 260 for receiving an instruction from the user is displayed on the liquid crystal display of the operation panel 150. The operation screen 260 displays a “Yes” key 262 for executing printing in response to the question “Do you want to execute printing?” And a “No” key 264 for not executing printing. When the “Yes” key 262 is pressed by the user, printing is executed with the converted monochrome image data as it is. On the other hand, when the “No” key 264 is pressed by the user, the printing process is stopped without executing the printing.

  Referring to FIG. 4 again, this program further includes a plurality of alternative image data (grayscale) to be proposed as alternative images of monochrome image data when it is determined in step S312 that an instruction to display alternative image data is given by the user. Scale image data) and a preview display process for previewing the generated substitute image data on the liquid crystal display of the operation panel 150. After step S316, the preview-displayed substitute image data is displayed. It is determined whether or not the user has selected it, and it is determined that one of the alternative image data previewed in step S318 and step S318 that branches the control flow according to the determination result is selected by the user. Selected The replacement image data, and a step S320 of the process to run to replace the image data for printing (converted monochrome image data).

  The program further determines, after step S320, whether or not a document on which alternative image data is to be displayed is selected when there are a plurality of read documents, and branches the control flow according to the determination result. When it is determined in S322 and the alternative image data previewed in step S318 is not selected by the user, it is determined whether an instruction to change the alternative image data has been issued by the user, and control is performed according to the determination result. Step S324 for branching the flow of step S326 and step S326 for executing processing for changing alternative image data when it is determined in step S324 that the user has issued an instruction to change alternative image data. When the process of step S326 is executed, the process returns to step S318. If another document is selected to display the substitute image data in step S322, the process returns to step S316.

  Referring to FIG. 7, when the user presses “alternative image display” key 254 shown in FIG. 5, a preview screen 270 for displaying a plurality of alternative image data on the liquid crystal display of operation panel 150 is displayed. The preview screen 270 includes a “display another pattern” key 272 for adding alternative image data having a pattern different from the displayed alternative image data, and all of the monochrome image data determined to be difficult to identify the boundary. On the other hand, a check box 274 operated to add alternative image data of a different pattern, a “return” key 276 for returning to the preview screen 250 shown in FIG. 5, and an “OK” key 278 are displayed. The

  The preview screen 270 further includes a “partial change” key 280 for changing the display of a partial area of the converted monochrome image data, and a “partial change” key 280 for replacing the selected substitute image data with the monochrome image data to be printed. A “replacement” key 282 and a “original image” key 284 for returning to the original monochrome image data after conversion are displayed. The preview screen 270 further displays a slide bar 286 for sliding the substitute image data, and an arrow key 288 for moving monochrome image data (a document page) determined to be difficult to identify the boundary.

  When the user presses the “display another pattern” key 272, alternative image data having a different pattern (light and shade display) is added to the selected monochrome image data. When the user presses the “display another pattern” key 272 with the check box 274 checked, an alternative image with a different pattern (light / dark display) is applied to all of the monochrome image data determined to be difficult to identify the boundary. Data is added. When adding alternative image data having a different pattern (grayscale display) to individual monochrome image data, the desired monochrome image data is selected with the arrow key 288, and in this state, the “display another pattern” key 272 is pressed. When the user presses, the above process is executed.

  When the user presses the “partial change” key 280, the mode is changed to a mode for changing the display of a partial area of the converted monochrome image data. As will be described later, when the user touches (designates) a desired area of the displayed monochrome image data, the area is changed to display a pattern (density) different from the plurality of alternative image data already displayed. . The changed image data is the selected substitute image data. Furthermore, after the user selects (touches) one of the plurality of alternative image data displayed in the preview, or after changing the display of a part of the converted monochrome image data, the “replacement” key 282 is pressed. When pressed, the image data for printing (converted monochrome image data) is replaced with the selected substitute image data. Printing is executed when the user presses an “OK” key 278.

  Referring to FIG. 4 again, this program determines whether or not a print execution instruction has been issued by the user when no other document for displaying substitute image data is selected in step S322 (see “FIG. 7“ Step S324 that branches the flow of control according to the determination result, and Step S324 determines that the user has issued a print execution instruction. Step S326 for executing printing.

  FIG. 8 is a detailed flow of step S302 of FIG. Referring to FIG. 8, in this routine, step S400 (region detection) is performed based on the color difference and density difference from the acquired color image data, and the color difference and density difference between adjacent regions are detected after step S400. After calculating step S402, after step S402, step S404 comparing the calculated calculated value n with a pre-stored threshold value, and after step S404, it is determined whether the calculated value n is smaller than the threshold value. Step S406 for branching the control flow according to the result.

  In this routine, when it is determined in step S406 that the calculated value n is smaller than the threshold value, the result (boundary identification is impossible) is stored in step S408, and in step S406, the calculated value n is determined to be greater than or equal to the threshold value. In this case, after step S410 for storing the result (boundary identification is possible) and after step S408 or step S410, it is determined whether or not the document whose boundary has been identified is the final document, and control is performed according to the determination result. Step S412 for branching the flow of If it is determined in step S412 that the document whose boundary has been identified is not the final document, the process returns to step S400 and the above processing is repeated. In step S408, in addition to the information that the boundary cannot be identified, information on which part cannot be identified is also stored.

  Referring to FIG. 9, for example, a color image original including graphics and characters as shown in FIG. 9A is read by the scanner unit 120 (see FIG. 1), and the acquired color image data is converted into monochrome image data (gray). In the case of conversion to (scale image data), as shown in FIG. 9B, each area is displayed not by a difference in color but only by a difference in brightness (density difference). In this case, if the density difference between adjacent regions is small, it is difficult to distinguish the boundary between adjacent regions. In step S302 shown in FIG. 4, it is determined whether or not the boundary between such adjacent regions is difficult to identify. In addition, when the converted monochrome image data is displayed as a preview in step S312 of FIG. 4, as shown in FIG. Display to the user easily whether it is difficult to identify.

  FIG. 10 is a detailed flow of step S308 in FIG. Referring to FIG. 10, this routine determines whether or not there are a plurality of documents whose boundary cannot be identified, step S500 for branching the flow of control according to the determination result, and a document whose boundary cannot be identified in step S500. Are determined to be a plurality of sheets, step S502 for notifying the number of originals whose boundary is difficult to identify, and step S500, where it is determined that the number of originals that cannot be identified is single (one). Step S504 for notifying that there is a document whose boundary is difficult to identify.

  Referring to FIG. 11, when it is determined that there is one read document and it is difficult to identify the boundary of the document (identification is impossible), notification screen 290 for notifying (warning) that effect is displayed on operation panel 150. Displayed on the LCD. On this notification screen 290, in response to the question “Do you want to confirm on the preview screen once?”, A “Yes” key 292 for confirming (displaying the preview screen) and not confirming (displaying the preview screen) No) “No” key 294 is displayed.

  Referring to FIG. 12, when there are a plurality of read originals and it is determined that it is difficult to identify a boundary (partially impossible) in a part or all of the originals, a notification screen for notifying (warning) to that effect 295 is displayed on the liquid crystal display of the operation panel 150. This notification screen 295 displays the page number of the document that is difficult to identify and the total number of documents that are difficult to identify. In addition, the notification screen 295 has a “Yes” key 296 for confirming (displaying the preview screen) in response to the question “Do you want to confirm once on the preview screen?” And not confirming (display the preview screen). “No” key 298 is displayed.

  11 and 12, when the user presses the “Yes” key 292 or 296, the process proceeds to step S312 in FIG. 4, and the preview screen 270 shown in FIG. 5 is displayed on the liquid crystal display. On the other hand, when the “NO” key 294 or 298 is pressed by the user, the process proceeds to step S314 in FIG. 4, and the operation screen 260 shown in FIG. 6 is displayed on the liquid crystal display.

  FIG. 13 is a detailed flow of step S316 in FIG. Referring to FIG. 13, this routine sets the density of each region so that the density difference between adjacent regions in the converted monochrome image data is greater than a preset (stored) threshold (eg, “64”). Step S600 for generating and storing a plurality of changed alternative images (substitute image data), and Step S602 for displaying the generated alternative image data as preview images on the liquid crystal display (see FIG. 7) after step S600. Including.

  Referring to FIG. 14, processing is performed so that, for example, one region is changed to black or white to change a color larger than a preset threshold value between adjacent regions. At this point, two alternative image patterns shown in FIGS. 14A and 14B are generated. In addition, when the density difference between adjacent areas is smaller than the threshold value, processing is performed for other portions (areas) so as to be outside the threshold value (so that a color difference or a density difference is generated between the areas) by the same method. Then, a plurality of patterns (a plurality of alternative image data) are generated and stored in combination at each location (area).

  FIG. 15 is a detailed flow of step S326 in FIG. Referring to FIG. 15, this routine determines whether or not an instruction to add alternative image data has been issued by the user (whether or not the “display another pattern” key 272 shown in FIG. 7 has been pressed by the user. Whether or not there are a plurality of originals whose boundary cannot be discriminated when it is determined in step S700 that an instruction to add alternative image data has been issued. Step S702 that branches the control flow according to the determination result, and when it is determined in step S702 that there are a plurality of originals whose boundaries cannot be determined, an alternative image of a different pattern at once It is determined whether or not an instruction to add data is given by the user (determining whether or not the check box 274 in FIG. 7 is checked), and depending on the determination result And a step S704 for branching the control flow.

  In this routine, if it is determined in step S702 that there are not plural (single) documents whose boundary cannot be determined, and in step S704, an instruction to add alternative image data of another pattern at once is issued. If it is determined by the user that the substitute image data having a different pattern (light and shade display) from the substitute image data displayed in the preview is generated by the substitute image generating unit 134, the substitute image data is generated after step S706. Step S708 for previewing alternative image data of another pattern. In this step S708, the generated alternative image data of another pattern (another pattern) is added to the preview screen 270 shown in FIG.

  Further, in this routine, the user has not instructed to add alternative image data of another pattern (substitute image data of different grayscale display) at once in step S704 (the check box 274 in FIG. 7 is not checked). Step S <b> 710 includes generating alternative image data of another pattern for the selected original, and generating alternative image data by the alternative image generation unit 134. The alternative image data of another pattern generated in step S710 is displayed as a preview in step S708.

  This routine further determines whether or not the user has given an instruction to change the display (pattern change) of a part of the converted monochrome image data when the user has not given an instruction to add alternative image data in step S700. Is determined (determining whether or not the “partial change” key 280 shown in FIG. 7 has been pressed by the user), and the flow of control branches according to the determination result, and monochrome image data in step S712 When it is determined that the user has instructed the display change of a part of the area, the display of the area specified by the user is displayed with a pattern (density) different from the plurality of alternative image data already displayed. Step S714 to change to. If it is determined in step S712 that the user has not instructed to change the display of a part of the monochrome image data, the process returns to step S700 to display another pattern shown in FIG. Wait until any of the “partial change” key 280 is pressed by the user.

  Referring to FIG. 16, when the user presses “partial change” key 280 shown in FIG. 7, the mode is switched to a mode for changing the display of a part of the converted monochrome image data. As shown in FIG. 16A, when the user touches the area whose display is to be changed with the finger 70, the display (density) of the touched area is changed as shown in FIG. When the user touches another area with the finger 70, the display of the touched area is changed.

  In this program, the order of step S302 and step S304 shown in FIG. 4 may be reversed from that in FIG. In other words, the boundary identification process may be executed after the monochrome conversion process. Further, the designation for changing the display of a part of the area in the monochrome image data shown in FIG. 16 may be a touch pen in addition to the user's finger 70.

<Operation>
With reference to FIGS. 1 to 13, 15, and 16, image forming apparatus 100 according to the present embodiment operates as follows. It is assumed that the image forming apparatus 100 is currently in a copy mode, and the user copies and prints a color document including a color image as a monochrome document.

  When the print start key 154a of the operation panel 150 is pressed, the scanner unit 120 (FIGS. 1 and 2) displays the image information of the document placed on the document placement table manually by the user or by the automatic document feeder. Read) to obtain color image data (step S300 shown in FIG. 4). The image forming apparatus 100 performs region separation based on the color difference and the density difference from the acquired color image data, and executes boundary identification processing (step S302 and FIG. 8 shown in FIG. 4). By this boundary identification processing, it is determined whether or not the boundary between adjacent areas can be identified in the converted monochrome image data, and the result is stored.

  The image forming apparatus 100 converts the acquired color image data into monochrome image data (step S304 shown in FIG. 4), and the converted monochrome image data by referring to the result of the boundary identification process makes it difficult to identify the boundary. It is determined whether it is data (step S306 shown in FIG. 4). If the converted monochrome image data is image data where it is not difficult to identify the boundary (the boundary is identifiable) (YES in step S306), the converted monochrome image data is printed as a monochrome document (FIG. 4). Step S326).

  On the other hand, if the converted monochrome image data is image data for which it is difficult to identify the boundary (the boundary cannot be identified) (NO in step S306), the notification screen 290 shown in FIG. 11 or the notification shown in FIG. A screen 295 is displayed on the liquid crystal display of the operation panel 150 (see FIG. 3), and a notification to that effect is given to the user (notification processing in FIG. 10). Notification screens 290 and 295 ask the user whether or not to display a preview screen. When the user presses “NO” key 294 or 298 (NO in step S310), the converted monochrome image data is not displayed as a preview, and operation screen 260 shown in FIG. 6 is displayed on the liquid crystal display. When the user presses “Yes” key 262 on operation screen 260 (YES in step S314), the monochrome image data that has been converted is copied and printed as a monochrome document. On the other hand, when the user presses “NO” key 264 on operation screen 260 (NO in step S314), the printing process is stopped without executing printing.

  When the user presses “Yes” key 292 or 296 on notification screen 290 or 295 (YES in step S 314), preview screen 250 shown in FIG. 5 is displayed on the liquid crystal display of operation panel 150. On this preview screen 250, monochrome image data (monochrome converted image) is previewed. At this time, as shown in FIG. 9B, by enclosing a portion where the boundary is difficult to identify with frames 60 and 62, which portion is difficult to identify is displayed in an easy-to-understand manner to the user.

  In the preview screen 250 shown in FIG. 5, a “substitute image display” key 254 and a “cancel” key 258 are displayed. When the user presses “substitute image display” key 254 (YES in step S312), substitute image generation unit 134 (see FIG. 1) generates a plurality of substitute image data, and displays the generated plurality of substitute image data as a preview. (Preview display process of FIG. 13). Specifically, the preview screen 270 shown in FIG. 7 is displayed on the liquid crystal display of the operation panel 150. On the other hand, when the user presses “cancel” key 258 on preview screen 250 shown in FIG. 5 (NO in step S312), operation screen 260 shown in FIG. 6 is displayed and the same operation as described above is performed.

  In the preview screen 270 shown in FIG. 7, if there is a substitute image that is similar to or close to the image of the user in the displayed substitute image data, the user selects it (YES in step S318). The user can replace the selected alternative image data with image data (converted monochrome image data) for printing by pressing the “replacement” key 282 (step S320 shown in FIG. 4).

  In the preview screen 270 shown in FIG. 7, when there is no substitute image in accordance with the user's image or close to the image in the displayed substitute image data, the substitute image data can be changed. By pressing either the “display another pattern” key 272 or the “partial change” key 280 on the preview screen 270 shown in FIG. 7, the alternative image data can be changed. When “display another pattern” key 272 or “partial change” key 280 is pressed by the user, it is determined that there is an instruction to change the substitute image data (YES in step S324).

  When the user presses “display another pattern” key 272 (YES in step S700 shown in FIG. 15), alternative image data having a pattern different from the displayed alternative image data is selected for the selected document. Display additional. As a result, the user can select alternative image data according to his / her own image or closer to the image. When there are a plurality of documents whose boundaries are difficult to discriminate, it is determined that it is difficult to identify the boundaries by pressing the “display another pattern” key 272 with the check box 274 in FIG. 7 checked. Alternative image data of different patterns is added to all the monochrome image data at once.

  When the user presses “partial change” key 280 (YES in step S712 shown in FIG. 15), the mode is switched to a mode for changing the display of a partial area of the converted monochrome image data. As shown in FIG. 16, when the user touches (designates) a desired area of the displayed monochrome image data, the area is changed to a display of a pattern (density) different from the plurality of alternative image data already displayed. Is done. The changed image data is the substitute image data selected by the user.

  By such an operation, the user can replace the substitute image data as the image or closer to the image with the monochrome image data to be printed with respect to the desired document. Thereafter, by pressing an “OK” key 278 shown in FIG. 7 (YES in step S324), the replaced alternative image data is printed as a monochrome document.

<Action and effect>
As described above, the image forming apparatus 100 according to the present embodiment generates a plurality of alternative image data in which the density of adjacent regions in the monochrome image data is different, and displays the generated plurality of alternative image data as a preview. The user can select desired substitute image data from the preview-displayed substitute image data. Therefore, by adjusting the converted monochrome image data based on the selected substitute image data, an output result (monochrome print original) close to the image intended by the user can be obtained. That is, an identifiable monochrome document intended by the user can be obtained. In addition, by displaying alternative image data in which the density of adjacent areas is different, it is possible to propose an easy-to-read print document, and thus it is possible to improve the readability of the obtained monochrome print document.

  In addition, when the user selects one of the plurality of alternative image data displayed in the preview, the image forming apparatus 100 selects monochrome image data for printing in response to the selection of the alternative image data by the user. Replace with the substitute image data and print. Thus, the user can easily obtain an identifiable monochrome print original intended by the user by selecting the desired alternative image data from the preview-displayed alternative image data.

  Since the image forming apparatus 100 also notifies the user when it is difficult to identify the boundary between adjacent areas in the converted monochrome image data, the user can easily reduce unnecessary printing.

  The image forming apparatus 100 also adds alternative image data having a pattern different from the plurality of alternative image data to the preview screen 270 according to a user instruction. For this reason, a monochrome print original as intended by the user or closer to the intended image can be obtained. Since the addition of the substitute image data can be performed individually, by adding the substitute image data to the desired document (selected document), a monochrome printed document closer to the image intended by the user can be obtained. . Since the substitute image data is not added to the document that does not require the addition of the substitute image data, in this case, the user can easily select the displayed substitute image data. The addition of the substitute image data can also be performed collectively.

  The image forming apparatus 100 can also convert a region designated by the user in the displayed monochrome image data into a pattern (display) different from the plurality of alternative image data. As a result, the user can create alternative image data closer to his / her own image, so that it is possible to obtain a monochrome printed document that matches the image intended by the user or closer to the intended image.

(Second Embodiment)
The image forming apparatus according to the present embodiment causes the user to determine whether or not the boundary can be identified by displaying a preview of the converted monochrome image data before executing copy printing.

<Hardware configuration>
The image forming apparatus according to the present embodiment is the same as the image forming apparatus 100 according to the first embodiment. For example, the present embodiment and the first embodiment can be switched by operating a setting button (not shown).

<Software configuration>
Referring to FIG. 17, in the image forming apparatus according to the present embodiment, each process except the processes in steps S1300, S1302, and S1304 is the same as each process executed by the computer program shown in FIG. . In addition, unlike the first embodiment, the present embodiment is configured to allow the user to determine whether or not the boundary can be identified. Therefore, Step S302, Step S306, Step S308, and Step shown in FIG. S310 is not included. Hereinafter, different parts will be described.

  After the step S304 for converting color image data into monochrome image data, the program displays a preview of the converted monochrome image data, and after step S1300, the boundary between adjacent regions in the converted monochrome image data is displayed. In step S1302 that allows the user to determine whether or not identification is possible, and in step S1302, if the user determines that it is not difficult to identify the boundary, it is determined whether or not to perform printing, and according to the determination result Step S1304 for branching the control flow.

  Referring to FIG. 18, in step S1300, a preview screen 800 for previewing the converted monochrome image data (monochrome converted image) is displayed on the liquid crystal display of operation panel 150 (see FIG. 3). The preview screen 800 includes a slide bar 802 for sliding the screen, a “substitute image display” key 804 for previewing a substitute image for the selected document, an “OK” key 806 for executing printing, and A “cancel” key 808 for canceling the printing process is displayed.

  In step S1302, when the user determines that there is monochrome image data whose boundary cannot be identified, the user selects the corresponding monochrome image data, and then presses the “substitute image display” key 804. Thereby, the alternative image data is preview-displayed with respect to the selected monochrome image data. In step S1304, it is determined which of the “OK” key 806 or the “Cancel” key 808 has been pressed. When the “OK” key 806 is pressed by the user, printing is executed with the converted monochrome image data. On the other hand, when the “cancel” key 808 is pressed by the user, the printing process is stopped.

<Operation>
Referring to FIGS. 17 and 18, the image forming apparatus according to the present embodiment operates as follows. The operations other than the display operation of monochrome image data and alternative image data are the same as those of the image forming apparatus 100 shown in the first embodiment. Therefore, detailed description of similar operations will not be repeated.

  After the color image data is converted to monochrome image data, the converted monochrome image data is previewed on the liquid crystal display of the operation panel 150. Specifically, preview screen 800 shown in FIG. 18 is displayed on the liquid crystal display of operation panel 150 (step S1300 shown in FIG. 17).

  The user looks at the displayed preview screen 800 and determines whether or not the boundary between adjacent regions in the converted monochrome image data can be identified (step S1302 shown in FIG. 17). If monochrome image data that is difficult to identify is found (NO in step S1302), the user selects the image data and presses “substitute image display” key 804 (YES in step S312). Thereby, the alternative image data is preview-displayed with respect to the selected monochrome image data.

  On the other hand, if monochrome image data in which the boundary between adjacent regions is difficult to identify is not found in the preview-displayed monochrome image data (YES in step S1302), there is no problem even if printing is performed as it is. . The user can execute printing by pressing the “OK” key 806 (YES in step S1304). Note that the user can press the “cancel” key 808 (NO in step S1304) to stop the printing process.

  If monochrome image data in which the boundary between adjacent areas is difficult to identify is found in the preview-displayed monochrome image data (NO in step S1302), the user presses a “cancel” key 808 (NO in step S1304). ), The printing process can be canceled. Monochrome image data in which the boundary between adjacent areas is difficult to identify has been found. If printing is performed in this state, the “OK” key 806 may be pressed.

<Action and effect>
In the image forming apparatus according to the present embodiment, as described above, by displaying the monochrome image data converted from the color image data as a preview, it is possible for the user to identify the boundary between adjacent regions in the monochrome image data. Can be judged. For this reason, for monochrome image data in which the boundary between adjacent regions is difficult to identify, unnecessary printing can be reduced by stopping output in the state as it is.

(Third embodiment)
In the present embodiment, an information processing terminal that transmits image data to the image forming apparatus executes various processes such as a process of presenting a substitute image and a process of identifying a boundary in the image data.

<Hardware configuration>
[Information processing apparatus 2200]
Referring to FIG. 19, information processing apparatus 2200 according to the present embodiment is a terminal apparatus such as a PC (Personal Computer) that is operated by a general user to use image forming apparatus 3000. The information processing apparatus 2200 is connected to the image forming apparatus 3000 via a network 30 including a LAN (Local Area Network) line. The image forming apparatus 3000 includes, for example, any of printers 3010 and 3020 or a digital multifunction peripheral 3030. The information processing apparatus 2200 and the image forming apparatus 3000 can mutually transmit and receive various data including image data.

  The information processing apparatus 2200 is installed with application programs such as a graphic drawing tool and a word processor, and a printer driver for realizing a print job of image data. The information processing apparatus 2200 creates image data for outputting an image including characters and graphics in accordance with a user instruction using the application program, and converts the created image data into a printer description language by a printer driver. Then, it can be transmitted to the image forming apparatus 3000.

  Referring to FIG. 20, information processing apparatus 2200 includes control unit 2230, HDD 2212, operation unit 2214, display unit 2216, and NIC 2218.

  The control unit 2230 is substantially a computer and includes a CPU 2232, a ROM 2234, and a RAM 2236. A BUS line 2228 is connected to the CPU 2232, and a ROM 2234 and a RAM 2236 are electrically connected to the BUS line 2228. The CPU 2232 executes various computer programs in response to an instruction from an external device including the image forming apparatus or the operation unit 2214 and the like, thereby performing desired processing such as operation of each unit of the information processing device 2200 and communication with the external device. Execute. The above-described various computer programs are stored in advance in the ROM 2234 or the HDD 2212, and are read from the ROM 2234 or the HDD 2212 and transferred to the RAM 2236 when a desired process is executed. The CPU 2232 reads and interprets a program instruction from an address in the RAM 2236 specified by a value stored in a register called a program counter (not shown) in the CPU 2232. CPU 2232 also reads data necessary for the operation from the address specified by the read instruction, and executes an operation corresponding to the instruction on the data. The execution result is also stored at an address specified by the instruction, such as a register in the RAM 2236, HDD 2212, and CPU 2232.

  Further, the HDD 2212, the operation unit 2214, the display unit 2216, and the NIC 2218 are electrically connected to the BUS line 2228. The HDD 2212 includes a magnetic storage medium, and stores various data including image data for displaying various screens on the display unit 2216.

  The HDD 2212 stores a printer driver for causing the image forming apparatus 3000 to execute a print job. By executing this printer driver, the information processing apparatus 2200 can realize an operation of causing the image forming apparatus 3000 to print an image based on the contents of the file designated by the user.

  In the present embodiment, the printer driver is also a computer program for realizing various processes such as a process for presenting a substitute image and a process for identifying a boundary in image data. When printing the color image data as a monochrome image by this printer driver, it is determined whether or not the boundary between adjacent areas in the monochrome image can be identified, and when it is determined that the boundary between adjacent areas is difficult to identify, A process of proposing a plurality of alternative images is executed.

  The HDD 2212 also stores a predetermined threshold value for determining whether or not the boundary between adjacent areas in the monochrome image data output to the image forming apparatus 3000 can be identified in the above processing. When this threshold value is smaller than the threshold values of color difference and density difference between adjacent areas in the image data generated by the information processing apparatus 2200, the boundary between adjacent areas in monochrome image data converted from color image data cannot be identified. Is set to be determined. For example, the density difference between adjacent regions after conversion into monochrome image data (grayscale image data) can be set to a value that is “64” (1/4 of 256 gradations).

  The printer driver may be provided by an external storage device in which the printer driver is recorded, for example, a recording medium such as a DVD. That is, a DVD as a printer driver recording medium may be mounted on a DVD drive (not shown) built in the information processing apparatus 2200, and the printer driver may be read from the DVD and installed in the HDD 2212.

  The HDD 2212 further stores various application software such as a graphic drawing tool and a word processor. By executing this application software, the information processing apparatus 2200 can realize an operation of editing the content of the file, an operation of browsing the content of the file, and the like.

  The operation unit 2214 is an input device including a keyboard for performing various inputs and character inputs in accordance with user instructions and the like, a pointing device such as a mouse, and the like. The operation unit 2214 is connected to the BUS line 2228 via an interface (not shown).

  The display unit 2216 is a display device including a liquid crystal display or the like for displaying a processing result of the information processing device 2200 and the like. Display unit 2216 is connected to BUS line 2228 via a video circuit (not shown) for driving display unit 2216.

  The information processing apparatus 2200 is connected to the network 30 via the NIC 2218 and can perform data communication with external apparatuses including the image forming apparatus 3000 and the like connected on the network 30. The information processing apparatus 2200 can transmit a command signal instructing execution of various processes such as a print job to the image forming apparatus 3000 via the NIC 2218. Note that color image data created by various application software such as a graphic drawing tool and a word processor can be converted into monochrome image data by a printer driver and printed as a monochrome document.

  A power supply (not shown) is connected to each part of the information processing apparatus 2200, and each part of the information processing apparatus 2200 operates when power is supplied from this power supply.

<Software configuration>
[Information processing apparatus 2200]
Referring to FIG. 21, the color / monochrome conversion printing of information processing apparatus 2200 according to the present embodiment is the same as that shown in FIG. 4 except that step S2300 is used instead of step S300 shown in FIG. This is the same as each process executed by the computer program shown in FIG. In step S2300, processing for obtaining color image data by execution or reception by an application program is executed. Note that operations and displays executed on the operation panel 150 of the image forming apparatus 100 are executed by the operation unit 2214, the display unit 2216, and the like.

<Operation>
Referring to FIG. 21, information processing apparatus 2200 according to the present embodiment operates as follows. The color / monochrome conversion printing processing operation excluding the color image data acquisition operation is the same as the color / monochrome conversion copy operation of the image forming apparatus 100 shown in the first embodiment. Therefore, detailed description of similar operations will not be repeated.

  The information processing apparatus 2200 according to the present embodiment is created using an application program, or acquired via a recording medium or communication. When the acquired color image data is printed in monochrome, it is converted into monochrome image data by the printer driver. At that time, the printer driver determines whether or not the boundary between adjacent regions in the converted monochrome image data can be identified. The subsequent operation is the same as the color / monochrome conversion copy processing operation of the image forming apparatus 100.

<Action and effect>
The information processing apparatus 2200 according to the present embodiment has the same effect as the image forming apparatus 100 described in the first embodiment.

(Fourth embodiment)
The information processing apparatus according to the present embodiment causes the user to determine whether the boundary can be identified by displaying the converted monochrome image data in a preview before printing.

<Hardware configuration>
The information processing apparatus according to the present embodiment is the same as the information processing apparatus 2200 according to the third embodiment. The present embodiment and the third embodiment can be switched, for example, by operating a setting button (not shown).

<Software configuration>
The color / monochrome conversion printing of the information processing apparatus according to the present embodiment is the same as the computer program shown in FIG. 17 except that step S2300 shown in FIG. 21 is used instead of step S300 shown in FIG. It is the same as each process executed by the above. Note that, as in the third embodiment, operations and display executed on the operation panel 150 of the image forming apparatus 100 are executed by the operation unit 2214, the display unit 2216, and the like.

<Operation>
The color / monochrome conversion printing operation excluding the color image data acquisition operation is the same as the color / monochrome conversion copy operation of the image forming apparatus shown in the second embodiment.

<Action and effect>
The information processing apparatus according to the present embodiment has the same effects as the image forming apparatus shown in the second embodiment.

(Modification of the first to fourth embodiments)
In the first and second embodiments, an example in which the present invention is applied to a digital multi-function peripheral that is an example of an image forming apparatus has been described. However, the present invention is not limited to such an embodiment. For example, the present invention may be applied to image forming apparatuses such as printers and copiers. Further, the present invention can be applied to such an image forming apparatus as long as the image forming apparatus can acquire color image data and convert it into monochrome image data even in a monochrome machine that cannot perform color printing. However, it is preferable to provide a display device capable of screen display.

  In the first and second embodiments, the image forming apparatus having the laser printer function has been described as an example. However, the present invention is not limited to such an embodiment. The image forming apparatus may be an apparatus having a printer function other than a laser printer. The image forming apparatus may be an apparatus having an inkjet printer function, for example.

  In the third and fourth embodiments, an example in which the present invention is applied to a PC that is an example of an information processing terminal has been described. However, the present invention is not limited to such an embodiment. Any information processing terminal other than a PC may be used as long as the information processing terminal can output image data to the image forming apparatus. Examples of information processing terminals other than PCs include portable information terminals such as mobile phones and smartphones.

  In the second and fourth embodiments, at least one of step S312 and step S1304 shown in FIG. 17 may not be included. For example, when the user determines that there is image data whose boundary is difficult to identify, by selecting the corresponding preview image, alternative image data corresponding to the selected image data is generated and the preview image is displayed. You may comprise as follows. Further, for example, when the user determines that there is no image whose boundary is difficult to identify, the converted monochrome image data may be printed.

  Note that the configuration and layout of the screens displayed on the operation panel of the image forming apparatus and the display unit of the information processing apparatus can be changed as appropriate.

  Embodiments obtained by appropriately combining the techniques disclosed above are also included in the technical scope of the present invention.

  The embodiment disclosed this time is merely an example, and the present invention is not limited to the embodiment described above. The scope of the present invention is indicated by each claim in the scope of claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are included. Including.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Control part 120 Scanner part 130 Image processing part 132 Boundary identification part 134 Alternative image generation part 140 Printer part 142 Image memory 144 Printing part 150 Operation panel 152 Display output part 154 Operation keys 250, 270, 800 Preview screen 260 Operation screen 290, 295 Notification screen 2200 Information processing device 2214 Operation unit 2216 Display unit 2228 BUS line 2230 Control unit 3000 Image forming apparatus

Claims (18)

A display device;
Conversion means for converting the input color image data into monochrome image data;
Two adjacent regions colored in different colors in the color image represented by the color image data, the boundary of the monochrome image represented by the monochrome image data being indistinguishable from each other A determination means for determining whether or not it exists;
Generating means for generating a plurality of alternative image data obtained by converting the densities of the two areas in the monochrome image data according to a predetermined conversion pattern when the determination by the determination means is affirmative;
Preview display means for causing the display device to display a plurality of substitute image data generated by the generation means as preview information;
First selection means for causing a user to select one of the plurality of alternative image data displayed on the display device by the preview display means;
When the determination by the determination unit is negative, an image based on the monochrome image data is output. When the determination by the determination unit is affirmative, the alternative image data selected by the user using the selection unit is output. And an image forming apparatus.   The preview display means includes means for causing the display device to display a preview image of the plurality of alternative image data generated by the generating means and a preview image of the monochrome image as preview information. The image forming apparatus described in 1. In response to the determination by the determination means being affirmative, a second selection means for causing the user to select whether to output the monochrome image as it is or to generate alternative image data by the generation means. Including
The output means is when the determination by the determination means is negative, and when the determination by the determination means is affirmative and the user has selected to print the monochrome image by the second selection means When the image based on the monochrome image data is output, the determination by the determination unit is affirmative, and the generation of the substitute image data by the second selection unit is selected, the first selection The image forming apparatus according to claim 1, further comprising: means for outputting the substitute image data selected by the user using the means. The color image data may represent a color image of a plurality of pages,
The determination means includes, for each of the one or more pages of the color image represented by the color image data, two adjacent regions colored in different colors in the color image, A page-by-page determination unit for determining whether or not there is a monochrome image represented by the monochrome image data whose boundary cannot be identified;
The generation unit converts the density of the two areas in the monochrome image data according to a predetermined conversion pattern when the determination by the determination unit is affirmative for each of the one-page or multiple-page color images. Including page-specific generation means for generating a plurality of alternative image data,
The preview display means uses the plurality of alternative image data generated by the generation means as preview information when the determination by the determination means is affirmative for each of the one-page or multiple-page color images, as the display device. The image forming apparatus according to claim 1, further comprising a page-by-page preview display unit for displaying the image on the screen. The color image data may represent a color image of a plurality of pages,
The determination means includes, for each of the one or more pages of the color image represented by the color image data, two adjacent regions colored in different colors in the color image, A page-by-page determination means for determining whether or not there is a monochrome image represented by the monochrome image data and whose boundary is not identifiable, and counting the number of the pages;
4. The image forming apparatus according to claim 1, further comprising notification means for notifying a user of the counting result in response to the counting result by the page-by-page determining means being not 0. 5. Image forming apparatus. In addition, in response to a user instruction, the image processing apparatus further includes additional generation means for additionally generating alternative image data with grayscale display different from the plurality of alternative image data,
The preview display means is a preview image of the alternative image data of the different shade display generated by the additional generation means, a preview image of the plurality of alternative image data generated by the generation means, and a preview image of the monochrome image The image forming apparatus according to claim 1, further comprising: a substitute image addition display unit for displaying the image as preview information on the display device. The color image data represents a color image of a plurality of pages,
The image forming apparatus further includes:
A plurality of image display means for causing the display device to display preview images of a plurality of monochrome image data converted by the conversion means as preview information;
Second selection means for causing a user to select one of a plurality of monochrome images displayed by the multiple image display means,
The additional generation unit generates, for the monochrome image selected by the second selection unit among the plurality of monochrome images, grayscale alternative image data different from the plurality of alternative image data. Including means,
The substitute image addition display means includes a preview image of the substitute image data generated for the monochrome image by the second selection means, a preview image of the plurality of substitute image data generated by the generation means, and the The image forming apparatus according to claim 6, further comprising means for displaying a preview image of a monochrome image on the display device as preview information. Display means for displaying on the display device a monochrome image of the monochrome image data converted by the conversion means;
Added alternative image data in which the area designated by the user among the areas of the monochrome image displayed by the display means is changed to a grayscale display different from the alternative image of the alternative image data generated by the generating means And additional generation means for generating at
The image forming apparatus according to claim 1, wherein the preview display unit includes a unit for causing the display device to display a preview image of the substitute image data generated by the additional generation unit. A display device;
Conversion means for converting the input color image data into monochrome image data;
Two adjacent regions colored in different colors in the color image represented by the color image data, the boundary of the monochrome image represented by the monochrome image data being indistinguishable from each other First preview display means for causing the display device to display, as preview information, a preview image of the monochrome image converted by the conversion means in order to make the user determine whether or not it exists;
A generating means for generating a plurality of alternative image data obtained by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern in response to a user instruction;
Second preview display means for causing the display device to display a plurality of substitute image data generated by the generation means as preview information;
Selection means for causing a user to select any of the plurality of alternative image data displayed on the display device by the second preview display means;
In response to a user's selection by the selection means, a process of outputting an image based on the monochrome image data and a process of outputting the substitute image data selected by the user using the selection means are selectively executed. An image forming apparatus including output means for performing the operation. A computer connected to the display device
Conversion means for converting the input color image data into monochrome image data;
Two adjacent regions colored in different colors in the color image represented by the color image data, the boundary of the monochrome image represented by the monochrome image data being indistinguishable from each other A determination means for determining whether or not it exists;
Generating means for generating a plurality of alternative image data obtained by converting the densities of the two areas in the monochrome image data according to a predetermined conversion pattern when the determination by the determination means is affirmative;
Preview display means for causing the display device to display a plurality of substitute image data generated by the generation means as preview information;
First selection means for causing a user to select one of the plurality of alternative image data displayed on the display device by the preview display means;
When the determination by the determination unit is negative, an image based on the monochrome image data is output. When the determination by the determination unit is affirmative, the alternative image data selected by the user using the selection unit is output. A printer driver program that functions as output means.   The preview display means includes means for causing the display device to display a preview image of the plurality of alternative image data generated by the generating means and a preview image of the monochrome image as preview information. The printer driver program described in 1. In response to the determination by the determination means being positive, the computer causes the user to select whether to output the monochrome image as it is or to generate alternative image data by the generation means. To further function as a selection means,
The output means is when the determination by the determination means is negative, and when the determination by the determination means is affirmative and the user has selected to print the monochrome image by the second selection means When the image based on the monochrome image data is output, the determination by the determination unit is affirmative, and the generation of the substitute image data by the second selection unit is selected, the first selection 12. The printer driver program according to claim 10, further comprising means for outputting the substitute image data selected by a user using means. The color image data may represent a color image of a plurality of pages,
The determination means includes, for each of the one or more pages of the color image represented by the color image data, two adjacent regions colored in different colors in the color image, A page-by-page determination unit for determining whether or not there is a monochrome image represented by the monochrome image data whose boundary cannot be identified;
The generation unit converts the density of the two areas in the monochrome image data according to a predetermined conversion pattern when the determination by the determination unit is affirmative for each of the one-page or multiple-page color images. Including page-specific generation means for generating a plurality of alternative image data,
The preview display means uses the plurality of alternative image data generated by the generation means as preview information when the determination by the determination means is affirmative for each of the one-page or multiple-page color images, as the display device. The printer driver program according to any one of claims 10 to 12, further comprising a page-by-page preview display means for displaying on a page. The color image data may represent a color image of a plurality of pages,
The determination means includes, for each of the one or more pages of the color image represented by the color image data, two adjacent regions colored in different colors in the color image, A page-by-page determination means for determining whether or not there is a monochrome image represented by the monochrome image data and whose boundary is not identifiable, and counting the number of the pages;
The printer driver program further causes the computer to function as notifying means for notifying the user of the counting result in response to the counting result by the page-by-page determining means being non-zero. One of the printer driver programs. In response to a user instruction, the computer is further caused to function as additional generation means for additionally generating grayscale display alternative image data different from the plurality of alternative image data,
The preview display means is a preview image of the alternative image data of the different shade display generated by the additional generation means, a preview image of the plurality of alternative image data generated by the generation means, and a preview image of the monochrome image The printer driver program according to claim 10, further comprising: alternative image addition display means for displaying the image as preview information on the display device. The color image data represents a color image of a plurality of pages,
The computer,
A plurality of image display means for causing the display device to display preview images of a plurality of monochrome image data converted by the conversion means as preview information;
Further functioning as second selection means for allowing the user to select one of a plurality of monochrome images displayed by the multiple image display means;
The additional generation means includes means for generating, for the monochrome image by the second selection means among the plurality of monochrome images, grayscale alternative image data different from the plurality of alternative image data. ,
The substitute image addition display means includes a preview image of the substitute image data generated for the monochrome image by the second selection means, a preview image of the plurality of substitute image data generated by the generation means, and the The printer driver program according to claim 15, comprising means for displaying a preview image of a monochrome image on the display device as preview information. The computer,
Display means for displaying on the display device a monochrome image of the monochrome image data converted by the conversion means;
Added alternative image data in which the area designated by the user among the areas of the monochrome image displayed by the display means is changed to a grayscale display different from the alternative image of the alternative image data generated by the generating means Further function as additional generation means for generating in
11. The printer driver program according to claim 10, wherein the preview display means includes means for causing the display device to display a preview image of the substitute image data generated by the additional generation means. A computer connected to the display device
Conversion means for converting the input color image data into monochrome image data;
Two adjacent regions colored in different colors in the color image represented by the color image data, the boundary of the monochrome image represented by the monochrome image data being indistinguishable from each other First preview display means for causing the display device to display, as preview information, a preview image of the monochrome image converted by the conversion means in order to make the user determine whether or not it exists;
A generating means for generating a plurality of alternative image data obtained by converting the densities of the two regions in the monochrome image data according to a predetermined conversion pattern in response to a user instruction;
Second preview display means for causing the display device to display a plurality of substitute image data generated by the generation means as preview information;
Selection means for causing a user to select any of the plurality of alternative image data displayed on the display device by the second preview display means;
In response to a user's selection by the selection means, a process of outputting an image based on the monochrome image data and a process of outputting the substitute image data selected by the user using the selection means are selectively executed. A printer driver program that functions as an output means for

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