JP6051526B2 - Image processing system, image forming apparatus, image processing program, and image processing method - Google Patents

Description

  The present invention relates to an image processing system, an image forming apparatus, an image processing program, and an image processing method.

  In general, an image processed in an image processing system such as a printer, a scanner, or a copier includes characters, graphics, and objects having image attributes. These objects may not only be displayed individually in different image areas, but may also be displayed overlapping each other.

  For example, Patent Document 1 below discloses a technique for extracting characters, graphics, and image objects displayed in an overlapping manner in an image read by a scanner or the like. In this technique, an edge of an object is used to determine which object the edge is included in, and an arbitrary object is extracted from the image. By using this technique, it is possible to select whether or not to display an object having an arbitrary attribute among character, graphics, and image objects.

  By the way, in an image processing system, the size of an image may be enlarged or reduced (hereinafter referred to as resolution conversion). For example, a thumbnail image is displayed by reducing the image. In such a case, the image processing system normally expresses the boundary of objects that overlap each other in an intermediate tone by performing an interpolation process.

  However, when there is an object that is not displayed in the resolution-converted image, there is a problem that a halftone pixel that exists at the boundary between the object to be displayed and the object that is not displayed is displayed and looks unnatural.

JP 2009-182626 A

  The present invention has been made to solve the above-described problems. Accordingly, an object of the present invention is to provide an image processing system, an image forming apparatus, an image processing program, and an image processing method that prevent the boundary portion of an object of a resolution-converted image from appearing unnatural.

  The above object of the present invention is achieved by the following.

(1) Print image data generating means for generating print image data based on the print data, and attribute data for generating attribute data indicating the object attribute of each pixel of the print image data based on the print data Generation means, resolution conversion means for converting the resolution of the printing image data and the attribute data, display object attribute acquisition means for acquiring object attributes to be displayed for the resolution-converted printing image data, and the resolution conversion Display image data generation means for generating display image data by rendering pixels having object attributes to be displayed with respect to the printed image data to be displayed, wherein the display image data generation means displays the first It exists at the boundary between the pixel with object attribute and the pixel with second object attribute to be displayed. The pixel to be drawn is drawn as a pixel having a halftone between the first object attribute and the second object attribute, and exists at the boundary between the pixel having the object attribute to be displayed and the pixel having the object attribute not to be displayed. An image processing system for generating the display image data so that pixels are not drawn .

  (2) When all the object attributes are selected as the object attributes to be displayed, the display image data generation unit draws all the pixels of the resolution-converted print image data, and displays the display image The image processing system according to (1), wherein data is generated.

(3) When a plurality of the object attributes are selected as the object attributes to be displayed, the display image data generation unit includes a predetermined number of pixels adjacent to a target pixel that does not correspond to a pixel having the object attributes to be displayed . the while drawing the pixel of interest if the pixel is present with two or more object attributes the displaying of, when a pixel having two or more object attributes the displaying of the predetermined number of the pixels do not exist The image processing system according to (1), wherein the display image data is generated without drawing the pixel of interest .

  (4) The image processing system according to any one of (1) to (3), further including print data generation means for generating the print data.

  (5) The image processing system according to any one of (1) to (4), further including display means for displaying a display image based on the display image data.

  (6) The apparatus according to any one of (1) to (5), further including a printing unit that prints a printing image based on the printing image data on a sheet using the attribute data. Image processing system.

(7) Print data receiving means for receiving print data, print image data generating means for generating print image data based on the print data, and each pixel of the print image data based on the print data Attribute data generating means for generating attribute data indicating the object attributes of the image, resolution conversion means for converting the resolution of the print image data and the attribute data, and object attributes to be displayed for the resolution-converted print image data A display object attribute acquiring unit for acquiring, a display image data generating unit for generating display image data by rendering pixels having an object attribute to be displayed with respect to the resolution-converted print image data; and the attribute data. a printing unit for printing on paper for printing image based on the print image data Te, the Then, the display image data generation means, for pixels existing at the boundary between the pixel having the first object attribute to be displayed and the pixel having the second object attribute to be displayed, The display image data is generated so that a pixel having a halftone with the second object attribute is drawn, and a pixel existing at a boundary between a pixel having an object attribute to be displayed and a pixel having an object attribute not to be displayed is not drawn. Image forming apparatus.

  (8) When all the object attributes are selected as the object attributes to be displayed, the display image data generation unit draws all the pixels of the resolution-converted print image data to display the display image The image forming apparatus according to (7), wherein data is generated.

(9) When a plurality of the object attributes are selected as the object attributes to be displayed, the display image data generation unit includes a predetermined number of pixels adjacent to a target pixel that does not correspond to a pixel having the object attributes to be displayed . the while drawing the pixel of interest if the pixel is present with two or more object attributes the displaying of, when a pixel having two or more object attributes the displaying of the predetermined number of the pixels do not exist The image forming apparatus according to (7), wherein the display image data is generated without drawing the pixel of interest .

  (10) The image forming apparatus according to any one of (7) to (9), further including display means for displaying a display image based on the display image data.

  (11) The image forming apparatus according to any one of (7) to (10), further including an input receiving unit that receives a user input of the object attribute to be displayed.

  (12) The image forming apparatus according to any one of (7) to (9), a print data generation unit that generates the print data, and an input reception unit that receives a user input of the object attribute to be displayed. An image processing system comprising: a client terminal comprising: display means for displaying a display image based on the display image data.

(13) A procedure for generating print image data based on print data, a procedure for generating attribute data indicating an object attribute of each pixel of the print image data based on the print data, and the print image a step of converting data and resolution the attribute data for the resolution-converted print image data, a step of acquiring the object attributes to display, for the resolution-converted print image data, comprising an object attributes to display In the procedure of drawing a pixel and generating display image data, and causing the computer to execute the display image data, a pixel having a first object attribute to be displayed and a second object attribute to be displayed For the pixel existing at the boundary with the pixel having the first object attribute and the previous The display image data is generated so that it is drawn as a pixel having a halftone with the second object attribute, and a pixel existing at the boundary between a pixel having an object attribute to be displayed and a pixel having an object attribute not to be displayed is not drawn. image processing program.

  (14) When all the object attributes are selected as the object attributes to be displayed, the procedure of generating the display image data draws all the pixels of the resolution-converted print image data, and The image processing program according to (13), wherein display image data is generated.

(15) When a plurality of the object attributes are selected as the object attributes to be displayed, in the procedure for generating the display image data, a predetermined number of pixels adjacent to the target pixel that does not correspond to the pixels having the object attributes to be displayed while drawing the pixel of interest when a pixel having an object attributes to two or more of said display in a pixel is present, pixels exist with two or more object attributes the displaying of the predetermined number of the pixels If not, the image processing program according to (13), wherein the display image data is generated without drawing the pixel of interest .

  (16) The image processing program according to any one of (13) to (15), further including a procedure for displaying a display image based on the display image data.

  (17) A computer-readable recording medium on which the image processing program according to any one of (13) to (16) is recorded.

(18) generating print image data based on the print data; generating attribute data indicating object attributes of each pixel of the print image data based on the print data; and the print image Resolution conversion of the data and the attribute data, acquisition of object attributes to be displayed for the resolution-converted printing image data, and display object attributes for the resolution-converted printing image data A step of drawing a pixel to generate display image data, and a step of generating the display image data in the step of generating the display image data and a pixel having a second object attribute to be displayed. For the pixels present at the boundary between the first object attribute and the second object It draws a pixel having a halftone and sex, so as not to draw the pixels existing in the boundary between the pixels having the object attributes that do not display a pixel having the object attributes to display, image processing method for generating the display image data .

  (19) When all the object attributes are selected as the object attributes to be displayed, in the step of generating the display image data, all pixels of the resolution-converted print image data are drawn, The image processing method according to (18), wherein display image data is generated.

(20) When a plurality of the object attributes are selected as the object attributes to be displayed, in the step of generating the display image data, a predetermined number of pixels adjacent to the target pixel not corresponding to the pixels having the object attributes to be displayed while drawing the pixel of interest when a pixel having an object attributes to two or more of said display in a pixel is present, pixels exist with two or more object attributes the displaying of the predetermined number of the pixels If not, the image processing method according to (18), wherein the display image data is generated without drawing the pixel of interest .

  According to the present invention, a display image is generated so as to draw only pixels existing at the boundary of an object to be displayed among pixels existing at the boundary of objects having different object attributes. Accordingly, it is possible to prevent a halftone pixel existing at the boundary between an object to be displayed and an object not to be displayed from appearing unnatural.

1 is a schematic configuration diagram of an image processing system according to a first embodiment of the present invention. It is a schematic block diagram of the client PC shown in FIG. It is a schematic block diagram of the image forming apparatus shown in FIG. It is a flowchart for demonstrating the outline of the process sequence of the image processing method in the 1st Embodiment of this invention. FIG. 5A is a diagram illustrating a data format of page image data, and FIG. 5B is a diagram illustrating a data format of tag image data. It is a flowchart for demonstrating S106 of FIG. FIG. 7A and FIG. 7B are diagrams for explaining a reduction interpolation method for a page image and a tag image. It is a figure which illustrates the input screen of "adjustment curve edit" of the program for tone curve adjustment in the 1st Embodiment of this invention. It is a figure for demonstrating the adjustment curve in the 1st Embodiment of this invention. FIG. 5 is a diagram illustrating an input screen of “adjustment curve editing” of the tone curve adjustment program displayed on the display unit of the image forming apparatus according to the first embodiment of the present invention. It is a flowchart for demonstrating S108 of FIG. FIG. 12A is a diagram showing a page image displaying all objects, and FIG. 12B is a diagram showing a display image displaying all objects. FIG. 12C is a diagram showing a display image displaying only image objects, and FIG. 12D is a diagram showing a display image displaying characters and image objects. It is a flowchart for demonstrating the production | generation of the display image data in the 2nd Embodiment of this invention. It is a figure for demonstrating the confirmation range of the attribute value which the surrounding pixel of an attention pixel has.

(First embodiment)
Hereinafter, an image processing system, an image forming apparatus, an image processing program, and an image processing method according to embodiments of the present invention will be described with reference to the drawings. 1 is a schematic configuration diagram of an image processing system according to a first embodiment of the present invention, FIG. 2 is a schematic configuration diagram of a client PC shown in FIG. 1, and FIG. 3 is a schematic diagram of an image forming apparatus shown in FIG. It is a block diagram.

  As illustrated in FIG. 1, the image processing system 100 according to the present embodiment includes a client PC (Personal Computer) 10 and an image forming apparatus 20. The client PC 10 and the image forming apparatus 20 are connected via a network 30 so that they can communicate with each other.

  The client PC 10 can be, for example, a personal computer, a workstation, a portable information terminal, or the like. The image forming apparatus 20 can be, for example, a printer, a copier, a facsimile, or a multifunction machine having the functions of these devices. The network 30 includes a LAN in which computers and network devices are connected according to standards such as Ethernet (registered trademark), token ring, and FDDI, or a WAN in which LANs are connected by a dedicated line.

  The client PC 10 generates print data as a client terminal and transmits it to the image forming apparatus 20. The print data includes image data printed by the image forming apparatus 20. As shown in FIG. 2, the client PC 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, an HDD (Hard Disk Drive) 13, a RAM (Random Access Memory) 14, and a network I / F (InterFace) 15. And an operation unit 16 and a display unit 17. Each of these components is connected to be communicable with each other via a bus.

  The CPU 11 generates print data by executing an application program and a program for transmitting print data (hereinafter referred to as a printer driver) as print data generation means. The application program and the printer driver are stored in advance in the ROM 12 that is a nonvolatile storage device or the hard disk drive HDD 13 that is a large-capacity storage device, and are transferred to the RAM 14 that is a volatile storage device when the CPU 11 executes the program. Is done.

  The network I / F 15 is connected to the image forming apparatus 20 via the network 30 and executes data transmission / reception between the client PC 10 and the image forming apparatus 20. In addition to being built in the client PC 10, the network I / F 15 may be mounted on the client PC 10 as an expansion device (LAN board).

  The operation unit 16 accepts user input as input accepting means and transmits it to the CPU 11. The operation unit 16 includes a pointing device such as a keyboard and a mouse, for example, and receives characters, various settings, and various instructions from the user.

  The display unit 17 displays various information such as a user input acceptance screen and a processing result as display means. The display unit 17 includes, for example, a liquid crystal display, a plasma display, a CRT (Cathode Ray Tube), and the like.

  In this embodiment, the application program includes a printing application program related to the printing process and an adjustment application related to various parameter adjustment processes. The application program may be in a form in which the printing application program and the adjustment application are integrated into one application program. An example of such an application program is a document creation program.

  The printing application program receives a print instruction and outputs the instruction to the printer driver. In this embodiment, the printing application program includes a GUI (Graphical User Interface) that serves as an interface between the user and the client PC 10. Therefore, the user can input information related to the print instruction from the operation unit 16 via the GUI input screen displayed on the display unit 17.

  The adjustment application program receives adjustment instructions for various parameters, adjusts the various parameters, and stores the adjusted information in the HDD 13 or the RAM 14. In the present embodiment, parameters related to printing processing such as a tone curve are mainly handled as the various parameters. Note that the tone curve is a curve representing a relationship regarding brightness (luminance) between a pixel value of an image of print data and a pixel value of an image at the time of printing.

  In this embodiment, an example in which a tone curve adjustment program is executed as the adjustment application program will be described later. The adjustment application program also includes a GUI, and the user can input information related to the adjustment instruction from the operation unit 16 via the GUI input screen displayed on the display unit 17. In addition to this, for example, a color profile adjustment program can be applied as the adjustment application program.

  The printer driver generates a print job based on an instruction from the printing application program. The print job includes page information about each page to be printed, print data, and the like. The print job is transmitted to the image forming apparatus 20 via the network I / F 15.

  The page information includes, for example, page number, page size (main scanning direction size and sub-scanning direction size), page resolution, and the like for each page.

  The print data includes a data file and a layout file. As the data file, a file described in a page description language such as PS (PostScript (registered trademark)), PDF (Portable Document Format), PCL (Printer Control Language), and XPS (XML Paper Specification) is used. In the layout file, an object described in PS is defined.

  The ROM 12 and the HDD 13 store various programs and parameters in addition to the application program and the printer driver. The RAM 14 stores the calculation results calculated by the CPU 11 when the application program is executed.

  As illustrated in FIG. 3, the image forming apparatus 20 includes a CPU 21, a ROM 22, an HDD 23, a RAM 24, a network I / F 25, an operation unit 26, a display unit 27, and a print output unit 28. Are connected so as to be able to communicate with each other.

  The CPU 21 executes a program for operating the image forming apparatus 20 (hereinafter referred to as an image processing program). The CPU 21 functions as printing image data generation means, attribute data generation means, display object attribute acquisition means, and display image data generation means by executing an image processing program. The image processing program is stored in advance in the ROM 22 that is a nonvolatile storage device or the hard disk drive HDD 23 that is a large-capacity storage device, and is transferred to the RAM 24 that is a volatile storage device when the CPU 21 executes the image processing program. .

  The network I / F 25 is connected to the client PC 10 via the network 30 and executes data transmission / reception between the image forming apparatus 20 and the client PC 10.

  The operation unit 26 receives user input as input receiving means and transmits it to the CPU 21. The operation unit 26 includes an input device such as a numeric keypad and a touch panel, and accepts various settings and various instructions from the user.

  The display unit 27 displays various information such as a user input acceptance screen and a processing result as display means. The display unit 27 includes, for example, a liquid crystal display. The liquid crystal display and the touch panel are integrally formed as a touch panel display.

  The print output unit 28 prints an image on paper based on the bitmap image data using a known image forming process such as an electrophotographic process as a printing unit. The details of the print output unit 28 will be omitted.

  Hereinafter, an outline of a processing procedure of the image processing method of the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart for explaining the outline of the processing procedure of the image processing method according to this embodiment. In the following, the processing procedure of the image processing method according to the present embodiment will be described by taking as an example the case where a tone curve adjustment program is executed as the adjustment application program.

  As shown in FIG. 4, first, print data is generated (step S101). Specifically, the client PC 10 receives a user instruction to activate the tone curve adjustment program via the operation unit 16. The CPU 11 starts execution of the tone curve adjustment program, generates print data from the printing application using a printer driver, and transmits the print data to the image forming apparatus 20 via the network 30. In the image forming apparatus 20, the CPU 21 receives the print data via the network I / F 25.

  At this time, the printer driver instructs the image forming apparatus 20 to store the print data in the HDD 23 of the image forming apparatus 20 using PJL (Printer Job Language) or the like (hereinafter referred to as a “save job” instruction). Called). The printer driver can also instruct to print an image based on the print data without saving the print data in the HDD 23 of the image forming apparatus 20 (hereinafter referred to as “normal print” instruction).

  Next, page image data is generated (step S102). The network I / F 25 of the image forming apparatus 20 receives the print data generated by the client PC 10 and transmits it to the CPU 21. The network I / F 25 and the CPU 21 function as print data receiving means. The CPU 21 analyzes the print data and generates page image data as print image data. The page image data is obtained by outputting an image to be printed as bitmap image data for each page. In the present embodiment, the page image has a resolution of, for example, 600 to 1200 dpi.

  FIG. 5A is a diagram illustrating a data format of page image data, and FIG. 5B is a diagram illustrating a data format of tag image data. As shown in FIG. 5A, in this embodiment, the page image data has pixel values corresponding to vertical size × horizontal size, and each pixel value is CMYK, that is, Cyan (C), Magenta (M), It includes information on the colors of Yellow (Y) and Black (K). The information regarding this color is expressed by the value of 0-255, for example. In addition to CMYK, RGB or other color spaces can also be applied.

  Next, tag image data is generated (step S103). The CPU 21 analyzes the print data and generates tag image data as attribute data. As shown in FIG. 5B, the tag image data is represented in the same vertical size × horizontal data format as the page image data. The vertical and horizontal positions of the pixels of the tag image data are associated with the vertical and horizontal positions of the pixels of the page image data, and each pixel of the tag image data indicates an object attribute of each pixel of the page image data. Has an attribute value. For example, the first pixel of the tag image data has an attribute value of the object attribute corresponding to the first pixel of the page image data.

  Therefore, in order to maintain the correspondence between the page image and the tag image, when converting the resolution of the page image, it is necessary to similarly convert the resolution of the tag image. That is, the page image and tag image always maintain the same vertical size × horizontal size after resolution conversion. In the present embodiment, the tag image has a resolution of, for example, 600 to 1200 dpi, similarly to the page image.

  In the present embodiment, the object attribute is any one of characters, graphics, and images. The characters are characters represented by ASCII codes, the graphics are line drawings represented by vectors, and the images are images such as photographs. These attributes are assigned attribute values to distinguish them from each other. In this embodiment, for example, 1, 2, and 3 are assigned to the attribute values of characters, graphics, and images, respectively. Note that an attribute value of 0 is assigned to an image area in which no object exists (hereinafter referred to as a non-object). The object attribute may be other than characters, graphics, and images, and the attribute value is not limited to the above. For example, transparency, transparency, overlay, etc. may be added as object attributes.

  As described above, by using the tag image data together with the page image data, it is possible to perform image adjustment independently for each object attribute. For example, it is possible to display only pixels corresponding to a photograph and adjust the contrast only in the photograph portion.

  Next, returning to FIG. 4 again, the print data output method is analyzed and determined (S104, S105). Specifically, when the image forming apparatus 20 receives an instruction to save the print data in the HDD 23, it is determined that the output method is “save job”. When the image forming apparatus 20 receives an instruction of “normal printing”, it is determined that the output method is “normal printing”. In this case (step S105: “normal printing”), the print output unit 28 prints a page image (step S110). Specifically, the CPU 21 transmits the page image data and tag image data generated in steps S102 and S103 to the print output unit 28. The print output unit 28 prints the page image on a sheet based on the page image data and the tag image data.

  On the other hand, when it is determined that the output method is “save job” (step S105: “save job”), the resolution of the page image and the tag image is converted (step S106). Hereinafter, with reference to FIG. 6 and FIG. 7, the process of converting the resolution of the page image and the tag image will be described in more detail. In the present embodiment, the process of converting the resolution of the page image and the tag image will be described by exemplifying a case where the thumbnail image for each image is generated by reducing the page image and the tag image. FIG. 6 is a flowchart for explaining S106 in FIG. 4, and FIGS. 7A and 7B are diagrams for explaining a reduction interpolation method for page images and tag images.

  As shown in FIG. 6, first, thumbnail image data is generated (step S201). In the present embodiment, an example in which the vertical and horizontal sizes of the page image and the tag image are reduced and interpolated by the area average method will be described. In the following, a method for generating a thumbnail image of a tag image out of a page image and a tag image will be described as a representative. A thumbnail image can be generated for the page image as well as the tag image. In the present embodiment, the thumbnail image is a reduced image having a resolution of 150 to 300 dpi, for example.

  For example, in FIG. 7A, the vertical size and the horizontal size of a tag image having a vertical size of 8 pixels × horizontal size of 8 pixels are reduced by half to generate a thumbnail image of vertical size of 4 pixels × horizontal size of 4 pixels. Indicates when to do. As shown in the figure, the tag image includes a black pixel image area and a white pixel image area in contact with the black pixel area. In the present embodiment, black pixels correspond to character objects, and white pixels correspond to image objects. In the thumbnail image obtained by reducing the tag image, the boundary between the character object and the image object is a halftone pixel (gray pixel) between the character object and the image object.

  Specifically, a method of reducing the vertical size and the horizontal size to ½ by the area average method is as shown in FIG. A pixel value of one pixel of the thumbnail image is calculated by averaging the pixel values in units of 2 vertical pixels × 2 horizontal pixels (= 4 pixels) of the tag image. For example, when the pixel values of the above four pixels of the tag image are 1, 1, 2, 3, 1.75 which is a value obtained by dividing the sum of these pixel values by the number of pixels 4 is 1.75. It becomes.

  In the above description, the case where the page image and the tag image are reduced and interpolated by the area average method is exemplified. However, the method for reducing and interpolating the page image and the tag image is not limited to the area average method, and for example, an interpolation algorithm such as a bilinear method or a bicubic method can be used.

  Next, page image data, tag image data, and thumbnail image data are stored (step S202). The CPU 21 stores the print job, page image data, tag image data, page image, and thumbnail image data of the tag image in the HDD 23 so that the correspondence relationship is maintained.

  Returning to FIG. 4 again, the object attribute to be displayed is acquired (step S107). The client PC 10 acquires a list of print jobs stored in the HDD 23 of the image forming apparatus 20 by the tone curve adjustment program, and selects a print job for adjusting the tone curve. The client PC 10 also acquires thumbnail image data of page images and tag images stored in the HDD 23 and a pre-adjustment tone curve stored in the HDD 23. Then, the client PC 10 discriminates object attributes from the thumbnail image data of the page image and the tag image, and transmits the object attributes to be displayed among these object attributes to the image forming apparatus 20. The CPU 21 acquires the object attribute to be displayed via the network I / F 25 and stores it in the HDD 23 or the RAM 24.

  Hereinafter, with reference to FIG. 8 and FIG. 9, a method for acquiring the object attribute to be displayed will be described in more detail. FIG. 8 is a diagram illustrating an input screen of “adjustment curve editing” of the tone curve adjustment program in this embodiment, and FIG. 9 is a diagram for explaining the adjustment curve. In the present embodiment, by adjusting the tone curve using the page image of the actual print data, it is possible to adjust the image according to the output print image.

  As shown in FIG. 8, the CPU 11 activates an input screen of “adjustment curve editing” of the tone curve adjustment program, and prompts the user to adjust the tone curve. In FIG. 8, in the “before adjustment” image display area, the display image of the thumbnail image of the acquired page image is displayed using the tone curve before adjustment. On the other hand, the display image of the thumbnail image of the page image is displayed in the “adjusted” image display area using the tone curve after being adjusted by the user. For example, as shown in FIG. 8, the thumbnail image of the “adjusted” image display area is compared with the thumbnail image of the image display area where the color tone of the character “A” is “before adjustment” by tone curve adjustment. It is lightly displayed.

  In the present embodiment, a thumbnail image of a page image is processed to generate a display image so as not to draw pixels that exist at the boundary between an object to be displayed and an object that is not to be displayed. Displayed in the “adjusted” image display area. A method for generating a display image will be described later.

  The user can select an object attribute of an object to be displayed in the “before adjustment” and “after adjustment” image display areas with a “display object” radio button. In the present embodiment, “all”, “text” (characters), “graphics”, and “image” (image) can be selected. “All” means all of “text”, “graphics”, and “image”. It is possible to select one or more object attributes from “text”, “graphics”, and “image”. It is also possible to set the display magnification with the “display magnification” spin button. The selected object attribute is transmitted to the RAM 24 of the image forming apparatus 20 via the network I / F 15.

  The current tone curve is displayed in the “adjustment curve” image display area. The tone curve is a curve representing a relationship regarding brightness (luminance) between a pixel value of an image of print data and a pixel value of an image at the time of printing. More specifically, this is realized by a conversion table in which the pixel value of the page image is an input value and the pixel value at the time of printing is an output value.

  For example, as shown in FIG. 9, a tone curve having an input value and an output value in the range of 0 to 100 can be applied. When this tone curve is applied, the output value for the input value 50 is 80.

  Before the tone curve adjustment, the acquired tone curve before adjustment is displayed in the “adjustment curve” image display area. The displayed tone curve can be adjusted by the user, for example, by moving the tone curve with the mouse or keyboard of the operation unit 16. The thumbnail image of the page image displayed in the “after adjustment” image display region changes following the adjustment of the tone curve. If the tone curve is adjusted, the conversion table is updated by performing interpolation processing such as spline interpolation.

  The user selects the object to which the tone curve adjustment is applied using the radio button located in the lower part of the “Adjustment Curve” image display area, and then confirms the tone curve adjustment by pressing the “Apply Curve” button. be able to. The adjusted tone curve information is stored in the HDD 23 of the image forming apparatus 20. On the other hand, the tone curve can be returned to the tone curve before adjustment by pressing the “reset” button.

  As a general application for adjusting the tone curve, it is used for raising the bottom of the pixel so that the dark part of the pixel becomes bright, lowering the bright part of the pixel so that it becomes dark, or increasing the contrast. As described above, in the present embodiment, the tone curve is adjusted on the input screen of “adjustment curve editing” of the adjustment application program as shown in FIG. Can be adjusted.

  In addition, an input screen for “adjustment curve editing” of the tone curve adjustment program may be displayed on the display unit 27 of the image forming apparatus 20. FIG. 10 is a diagram illustrating an input screen for “adjustment curve editing” of the tone curve adjustment program displayed on the display unit of the image forming apparatus.

  Even when “adjustment curve editing” is executed by the image forming apparatus 20, the process until print data is transmitted from the client PC 10 and stored in the image forming apparatus 20 is executed by the client PC 10 described above. It is the same as the case of doing.

  In the case of such a configuration, the CPU 21 activates an input screen of “adjustment curve editing” of the tone curve adjustment program and displays it on the display unit 27.

  The user selects a print job for executing tone curve adjustment from the list of print jobs displayed on the display unit 27. The display unit 27 displays a thumbnail image, a tone curve, and the like of the page image of the selected print job. The contents displayed on the display unit 27 and the adjustment contents of the tone curve are the same as the adjustment of the tone curve shown in FIG. The user inputs information for adjusting the tone curve via a hardware key of the operation unit 26 of the image forming apparatus 20 or a touch panel.

  Returning again to FIG. 4, display image data is generated (step S108). Hereinafter, a method for generating display image data will be described with reference to FIG. FIG. 11 is a flowchart for explaining S108 of FIG. In the process of the flowchart shown in FIG. 11, all the pixels of the thumbnail image of the tag image are sequentially scanned as the target pixel. Then, it is determined whether or not the pixel of interest is a pixel to be drawn, and if it is a pixel to be drawn, drawing is performed.

  First, it is determined whether or not all objects have been selected (step S301). Specifically, the CPU 21 determines whether or not all defined object attributes, that is, “text”, “graphics”, and “image” in the present embodiment are selected as object attributes to be displayed. To check. If all objects have been selected (step S301: YES), the pixel of interest is drawn (step S306). When all the objects are selected, all the objects are displayed, so that all the pixels at the boundary between the objects can be drawn.

  Then, it is determined whether or not all the pixels of the thumbnail image are the target pixels (step S307). When all the pixels of the thumbnail image are the target pixels (step S307: YES), the process proceeds to step S109 in FIG. On the other hand, when all the pixels of the thumbnail image are not the target pixel (step S307: NO), the target pixel is changed to the next pixel (step S308), and the process proceeds to step S302.

  On the other hand, when there is an unselected object (step S301: NO), it is determined whether the target pixel is an attribute value of the selected object attribute (step S302). In the present embodiment, it is determined whether the pixel of interest has any attribute value of “text”, “graphics”, and “image”. When the target pixel is the attribute value of the selected object attribute (step S302: YES), the target pixel is drawn (step S306). Then, it is determined whether or not all the pixels of the thumbnail image are the target pixels (step S307). The subsequent processing is as described above.

  On the other hand, when the target pixel is not the attribute value of the selected object attribute (step S302: NO), it is determined whether or not a plurality of object attributes are selected (step S303). If the target pixel does not have the attribute value of the selected object attribute, the target pixel has a halftone of different object attributes, or has a non-object attribute value. The pixel of interest has a halftone when the pixel of interest exists at a boundary between different object attributes. When the target pixel has a non-object attribute value, the target pixel is directly rendered as a non-object.

  If a plurality of object attributes are not selected (step S303: NO), it is determined whether or not all the pixels of the thumbnail image are the target pixel without drawing the target pixel (step S307). The subsequent processing is as described above.

  When a plurality of object attributes are not selected, at least one of the objects adjacent to the target pixel at the boundary is an object that is not displayed, so that the target pixel is not drawn.

  On the other hand, when a plurality of object attributes are selected (step S303: YES), the attribute values of 8 pixels adjacent to the target pixel are confirmed (step S304). In the present embodiment, the plurality of object attributes are two of “text”, “graphics”, and “image”. In order for the pixel of interest to be present at the boundary of the object to be displayed, it is necessary that pixels of attribute values of the two object attributes selected in the eight pixels adjacent to the pixel of interest exist. When there are four or more defined object attributes, it is necessary that two or more selected attribute values of the object attribute are present in the eight pixels adjacent to the target pixel.

  Then, it is determined whether or not there are two or more pixels having the attribute value of the selected object attribute in the adjacent eight pixels (step S305). When there are two or more pixels having the attribute value of the selected object attribute in the adjacent eight pixels (step S305: YES), the target pixel is drawn (step S306). Then, it is determined whether or not all the pixels of the thumbnail image are the target pixels (step S307). The subsequent processing is as described above.

  On the other hand, when a plurality of object attributes are not selected (step S303: NO), or when two or more pixels having the attribute value of the selected object attribute do not exist in the adjacent eight pixels (step S305: NO). Do not draw the pixel of interest. Then, it is determined whether or not all the pixels of the thumbnail image are the target pixels (step S307). The subsequent processing is as described above.

  As described above, according to the process of the flowchart illustrated in FIG. 11, the CPU 21 draws all the pixels when all the object attributes are selected for the thumbnail image of the page image. Further, the CPU 21 draws only the pixels existing at the boundary of the object to be displayed among the pixels existing at the boundary of the objects having different object attributes. Display images generated by such image processing will be described below with reference to FIGS. 12 (A) to 12 (D).

  FIG. 12A is a diagram showing a page image displaying all objects, and FIG. 12B is a diagram showing a display image displaying all objects. FIG. 12C is a diagram showing a display image displaying only image objects, and FIG. 12D is a diagram showing a display image displaying characters and image objects.

  As shown in FIG. 12A, a page image as an original image (original) includes a character object “A” having a character (text) attribute, a graphics object having a rounded graphics attribute, and an image ( Image object with image attribute is included. In FIG. 8, when “all” is selected by the “display object” radio button, as shown in FIG. 12B, halftone pixels at the boundary between the character object and the graphics object, the character object, and the image object And halftone pixels are displayed.

  On the other hand, when only the image attribute is selected as the object attribute to be displayed, halftone pixels between the character object and the image object are not displayed as shown in FIG.

  When a character and an image attribute are selected as object attributes to be displayed, halftone pixels between the character object and the image object are displayed as shown in FIG. 12D, and the character object and the graphics object are displayed. The halftone pixels in between are not displayed.

  Returning to FIG. 4 again, the display image is displayed (step S109). Specifically, the CPU 11 displays the display image generated in step S108 in the “before adjustment” image display area and the “after adjustment” image display area in the “adjustment curve editing” input screen of the tone curve adjustment program. To do.

  Next, a page image is printed (step S110). Specifically, the CPU 21 transmits the page image data and tag image data generated in steps S102 and S103 and the adjusted tone curve setting information to the print output unit 28. The print output unit 28 prints the page image on paper using the tag image data and the adjusted tone curve setting information.

  As described above, according to the process of the flowchart shown in FIG. 4, the image forming apparatus 20 uses the print data generated by the client PC 10 and the tag image indicating the object attribute of each pixel of the page image data. Generate data. Further, the image forming apparatus 20 performs resolution conversion on the page image data and the tag image data, and acquires object attributes to be displayed for the page image data subjected to the resolution conversion.

  Then, the image forming apparatus 20 performs image processing on the thumbnail image of the page image so as to draw only the pixels existing at the boundary of the object to be displayed among the pixels existing at the boundary of the objects having different object attributes. Generate a display image. The generated display image is displayed on the display unit 17 of the client PC 10. The image forming apparatus 20 prints a page image on a sheet using the tag image and the adjusted tone curve.

  As described above, the described embodiment has the following effects.

  (A) According to the present embodiment, a display image is generated so as to draw only pixels existing on the boundary of the object to be displayed among the pixels existing on the boundary of objects having different object attributes. Accordingly, it is possible to prevent a halftone pixel existing at the boundary between an object to be displayed and an object not to be displayed from appearing unnatural. Further, it is possible to prevent the display of halftone pixels existing at the boundary between objects to be displayed from being lost.

  (B) In this embodiment, by determining the attribute value of the object attribute in each pixel of the thumbnail image, it is possible to prevent display of a halftone pixel existing at the boundary between the object to be displayed and the object not to be displayed. ing. Therefore, it is possible to suppress a burden on image processing for generating a thumbnail image.

(Second Embodiment)
In the first embodiment, it has been described that when a plurality of object attributes are selected as object attributes to be displayed, the attribute value is confirmed within a range of 8 pixels adjacent to the target pixel. In the second embodiment, a case will be described in which the range for checking attribute values is further expanded. In the present embodiment, the configuration other than the configuration for further expanding the range for checking the attribute value is the same as the configuration of the first embodiment. Below, in order to avoid duplication of description, description is abbreviate | omitted about the same structure as 1st Embodiment.

  The image processing system, the image forming apparatus, the image processing program, and the image processing method of the present embodiment will be described with reference to FIGS. FIG. 13 is a flowchart for explaining generation of display image data in the present embodiment, and FIG. 14 is a diagram for explaining a confirmation range of attribute values of peripheral pixels of the target pixel. 14A is a diagram showing eight pixels adjacent to the target pixel, FIG. 14B is a diagram showing 24 pixels centered on the target pixel, and FIG. 14C is a diagram centering on the target pixel. It is a figure which shows 48 pixels.

  Steps S401 to S404 shown in FIG. 13 are the same as steps S301 to S304 shown in FIG. 11 of the first embodiment, and thus the description thereof will be omitted, and the processing after step S405 will be described.

  In step S404, after confirming the attribute values of the eight pixels adjacent to the target pixel, it is determined whether or not there are two or more selected attribute values of the object attribute in the eight pixels adjacent to the target pixel. (Step S405). When there are two or more pixels having the attribute value of the selected object attribute in the adjacent eight pixels (step S405: YES), the target pixel is drawn (step S407). Then, it is determined whether or not all the pixels of the thumbnail image are the target pixels (step S408). The subsequent processing is the same as Step S307 and Step S308 of the first embodiment.

  On the other hand, when there are no pixels having two or more selected attribute values of the object attribute in the eight pixels adjacent to the target pixel (step S405: NO), the pixel confirmation range is expanded (step S406). Specifically, when 8 pixels adjacent to the pixel of interest have a halftone pixel value, the pixel of interest shown in FIG. 14B is centered on the 8 pixels adjacent to the pixel of interest shown in FIG. The confirmation range is expanded to 24 pixels. Further, when 24 pixels centered on the target pixel have halftone pixel values, the confirmation range is expanded from 24 pixels centered on the target pixel to 48 pixels centered on the target pixel shown in FIG. .

  In addition, you may comprise so that the confirmation range of a pixel may be preset. In addition, when a pixel having an attribute value of two or more selected object attributes cannot be confirmed in a predetermined confirmation range, the target pixel may not be drawn.

  As described above, the described embodiment has the following effects in addition to the effects of the first embodiment.

  (C) Since the range for confirming the attribute value of the selected object attribute is further expanded, the target pixel exists at the boundary of the object to be displayed even when the eight pixels adjacent to the target pixel have halftone pixel values It can be determined whether or not to do so.

(Third embodiment)
In the first and second embodiments, the process of generating the print data in step S101 in FIG. 4 is executed by the client PC, and the process of generating the page image data in steps S102 to S110 or the process of printing the page image is performed as an image. The form to be executed by the forming apparatus has been described. In the third embodiment, a description will be given of a configuration in which the process of generating print data in steps S101 to S109 or the process of displaying a display image is executed by the client PC, and only the process of S110 is executed by the image forming apparatus. The present embodiment is the same as the first embodiment with respect to other configurations. Below, in order to avoid duplication of description, description is abbreviate | omitted about the same structure as 1st Embodiment. Hereinafter, the image processing system, the image forming apparatus, the image processing program, and the image processing method according to the present embodiment will be described with reference to FIGS.

  In the present embodiment, the CPU 11 of the client PC 10 shown in FIG. 2 executes the image processing program. The CPU 11 functions as printing image data generation means, attribute data generation means, display object attribute acquisition means, and display image data generation means by executing an image processing program. The image processing program is stored in advance in the ROM 12 that is a nonvolatile storage device or the hard disk drive HDD 13 that is a large-capacity storage device, and is transferred to the RAM 14 that is a volatile storage device when the CPU 11 executes the image processing program. .

  The CPU 11 generates print data, generates page image data and tag image data indicating the object attribute of each pixel of the page image data based on the print data, and converts the resolution of the page image data and the tag image data. In the present embodiment, the generated page image data, tag image data, resolution-converted page image data, and tag image data are stored in the HDD 13. Further, the CPU 11 acquires object attributes to be displayed for the page image data whose resolution has been converted. Then, the CPU 11 draws pixels having object attributes to be displayed for the page image data subjected to resolution conversion. Further, the CPU 11 generates display image data by drawing only the pixels existing at the boundary of the object to be displayed among the pixels existing at the boundary of the objects having different object attributes.

  The CPU 11 transmits page image data, tag image data, and information regarding the adjusted tone curve to the image forming apparatus 20 via the network I / F 15.

  On the other hand, the image forming apparatus 20 receives page image data, tag image data, and information regarding the adjusted tone curve from the client PC 10 via the network I / F 25 and stores them in the HDD 23. The print output unit 28 prints a page image on paper based on these data.

  As described above, the described embodiment has the following effects in addition to the effects of the first and second embodiments.

  (D) The amount of communication data between the client PC 10 and the image forming apparatus 20 via the network 30 can be reduced.

  As described above, in the embodiments, the image processing system, the image forming apparatus, the image processing program, and the image processing method of the present invention have been described. However, it goes without saying that the present invention can be appropriately added, modified, and omitted by those skilled in the art within the scope of the technical idea.

  For example, in the first and second embodiments, the case where the page image and the tag image are reduced as an example of resolution conversion has been described. However, the present invention can be applied not only when an image is reduced, but also when the image is enlarged.

10 Client PC,
11 CPU of client PC,
12 ROM of client PC,
13 HDD of client PC,
14 RAM of client PC,
15 Network interface of client PC,
16 Operation part of client PC,
17 Display part of client PC,
20 image forming apparatus,
21 CPU of the image forming apparatus,
22 ROM of the image forming apparatus,
23 HDD of image forming apparatus,
24 RAM of the image forming apparatus,
25 Network interface of image forming apparatus,
26 Operation unit of the image forming apparatus,
27 a display unit of the image forming apparatus,
28 Print output unit of image forming apparatus,
30 network,
100 Image processing system.

Claims (20)

Printing image data generating means for generating printing image data based on the printing data;
Attribute data generating means for generating attribute data indicating an object attribute of each pixel of the print image data based on the print data;
Resolution conversion means for converting the resolution of the image data for printing and the attribute data;
Display image attribute acquisition means for acquiring an object attribute to be displayed for the resolution-converted print image data;
Display image data generation means for generating display image data by rendering pixels having object attributes to be displayed with respect to the resolution-converted print image data ,
The display image data generation means includes
The pixel existing at the boundary between the pixel having the first object attribute to be displayed and the pixel having the second object attribute to be displayed has a halftone between the first object attribute and the second object attribute. Draw as pixels,
Do not draw pixels that exist at the boundary between pixels that have object attributes to display and pixels that have object attributes that do not display.
An image processing system for generating the display image data . When all the object attributes are selected as the object attributes to be displayed,
The image processing system according to claim 1, wherein the display image data generation unit generates the display image data by drawing all pixels of the resolution-converted print image data. When a plurality of the object attributes are selected as the object attributes to be displayed,
The display image data generation means, the target pixel when there is a pixel having two or more object attributes the displaying of a predetermined number of the pixels adjacent to the pixel of interest does not correspond to the pixel having the object attributes to display while drawing a, when pixels having two or more object attributes the displaying of the predetermined number of the pixel does not exist, and generates said display image data without rendering the pixel of interest The image processing system according to claim 1.   The image processing system according to claim 1, further comprising print data generation means for generating the print data.   The image processing system according to claim 1, further comprising display means for displaying a display image based on the display image data.   The image processing system according to claim 1, further comprising a printing unit that prints a printing image based on the printing image data on a sheet using the attribute data. Print data receiving means for receiving print data;
Printing image data generating means for generating printing image data based on the printing data;
Attribute data generating means for generating attribute data indicating an object attribute of each pixel of the print image data based on the print data;
Resolution conversion means for converting the resolution of the image data for printing and the attribute data;
Display image attribute acquisition means for acquiring an object attribute to be displayed for the resolution-converted print image data;
Display image data generation means for generating display image data by rendering pixels having an object attribute to be displayed with respect to the resolution-converted printing image data;
Printing means for printing a printing image based on the printing image data on paper using the attribute data ;
The display image data generation means includes
The pixel existing at the boundary between the pixel having the first object attribute to be displayed and the pixel having the second object attribute to be displayed has a halftone between the first object attribute and the second object attribute. Draw as pixels,
Do not draw pixels that exist at the boundary between pixels that have object attributes to display and pixels that have object attributes that do not display.
An image forming apparatus for generating the display image data . When all the object attributes are selected as the object attributes to be displayed,
The image forming apparatus according to claim 7, wherein the display image data generation unit generates the display image data by drawing all pixels of the resolution-converted print image data. When a plurality of the object attributes are selected as the object attributes to be displayed,
The display image data generation means, the target pixel when there is a pixel having two or more object attributes the displaying of a predetermined number of the pixels adjacent to the pixel of interest does not correspond to the pixel having the object attributes to display while drawing a, when pixels having two or more object attributes the displaying of the predetermined number of the pixel does not exist, and generates said display image data without rendering the pixel of interest The image forming apparatus according to claim 7.   The image forming apparatus according to claim 7, further comprising a display unit configured to display a display image based on the display image data.   The image forming apparatus according to claim 7, further comprising an input receiving unit that receives a user input of the object attribute to be displayed. An image forming apparatus according to any one of claims 7 to 9,
A client terminal comprising: print data generating means for generating the print data; input receiving means for receiving user input of the object attributes to be displayed; and display means for displaying a display image based on the display image data;
An image processing system. A procedure for generating image data for printing based on the print data;
Generating attribute data indicating an object attribute of each pixel of the print image data based on the print data;
A procedure for converting the resolution of the image data for printing and the attribute data;
A procedure for obtaining object attributes to be displayed for the resolution-converted print image data;
A procedure for rendering display image data by rendering pixels having object attributes to be displayed with respect to the resolution-converted printing image data;
To the computer ,
In the procedure of generating the display image data,
The pixel existing at the boundary between the pixel having the first object attribute to be displayed and the pixel having the second object attribute to be displayed has a halftone between the first object attribute and the second object attribute. Draw as pixels,
Do not draw pixels that exist at the boundary between pixels that have object attributes to display and pixels that have object attributes that do not display.
An image processing program for generating the display image data . When all the object attributes are selected as the object attributes to be displayed,
14. The image processing program according to claim 13, wherein in the procedure of generating the display image data, the display image data is generated by drawing all pixels of the resolution-converted printing image data. When a plurality of the object attributes are selected as the object attributes to be displayed,
In the procedure of generating the display image data, when there are two or more pixels having the object attribute to be displayed in a predetermined number of pixels adjacent to the pixel of interest not corresponding to the pixel having the object attribute to be displayed, While drawing the pixel of interest, if there is no pixel having two or more object attributes to be displayed in the predetermined number of pixels, generating the display image data without drawing the pixel of interest The image processing program according to claim 13, wherein the program is an image processing program.   16. The image processing program according to claim 13, further comprising a procedure for displaying a display image based on the display image data.   The computer-readable recording medium which recorded the image processing program of any one of Claims 13-16. Generating image data for printing based on the print data;
Generating attribute data indicating an object attribute of each pixel of the print image data based on the print data;
Converting the resolution of the image data for printing and the attribute data;
Obtaining the object attribute to be displayed for the resolution-converted print image data;
Drawing resolution-converted print image data with pixels having object attributes to be displayed, and generating display image data; and
In the step of generating the display image data,
The pixel existing at the boundary between the pixel having the first object attribute to be displayed and the pixel having the second object attribute to be displayed has a halftone between the first object attribute and the second object attribute. Draw as pixels,
Do not draw pixels that exist at the boundary between pixels that have object attributes to display and pixels that have object attributes that do not display.
An image processing method for generating the display image data . When all the object attributes are selected as the object attributes to be displayed,
19. The image processing method according to claim 18, wherein in the step of generating the display image data, the display image data is generated by drawing all pixels of the resolution-converted printing image data. When a plurality of the object attributes are selected as the object attributes to be displayed,
In the step of generating the display image data, when there are two or more pixels having the object attribute to be displayed in a predetermined number of pixels adjacent to the target pixel not corresponding to the pixel having the object attribute to be displayed, While drawing the pixel of interest, if there is no pixel having two or more object attributes to be displayed in the predetermined number of pixels, generating the display image data without drawing the pixel of interest The image processing method according to claim 18, wherein: