JP2011188267A - Image forming apparatus and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing an influence of a background in an image before overlay execution more than a prior art during overlay execution. <P>SOLUTION: An image forming apparatus includes: an overlay executing means which executes overlay for combining image data of a document and image data of a form; and a translucent color receiving means for receiving the designation of a translucent color for at least either the image data of the document or the image data of the form. When executing the overlay, the overlay executing means handles a translucent color which is received by the translucent color receiving means as transparency (S155, S156, S157). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus capable of executing overlay that combines image data of a document that is variable information that changes for each page and form image data that is fixed information that does not change for each page.

  Conventionally, as an image forming apparatus capable of executing overlay, a frame memory capable of storing dot pattern data for one page of paper and a print head for printing dot pattern data written in the frame memory on paper are provided. When performing overlay so that the document image is placed in front of the form image, the form image data is written to the frame memory and then the document image data is written to the frame memory. 2. Description of the Related Art When overlaying is performed so that an image of a document is placed on the back side of a form image, a printer device is known that writes image data of a document in a frame memory and then writes the image data of the document in the frame memory. (For example, refer to Patent Document 1).

  In the printer device described in Patent Document 1, a graphic part such as a ruled line, a frame line, and a company logo created by a computer is opaque, and a part other than the graphic, that is, a background part is transparent. It is used as an image.

  Here, in the image read by the scanner, not only the graphic portion but also the background portion becomes opaque. 2. Description of the Related Art Conventionally, as an image forming apparatus capable of executing overlay, a copying apparatus that uses an image read by a scanner as a form image is also known (for example, see Patent Document 2).

Japanese Patent No. 2726752 JP 2001-358929 A

  The background portion should be transparent because it is originally a portion that the user does not intend to print. However, the copying apparatus described in Patent Document 2 overwrites the original image data on the form image data because the background portion in the original image is transparent, but the background portion in the original form image is opaque. When combined by processing, the background portion of the form image is printed at the portion of the combined image where the background portion of the form image and the background portion of the document image overlap. That is, in the copying apparatus described in Patent Document 2, when the image data of the document is combined with the image data of the form by overwriting, the background portion of the form image and the background portion of the document image of the combined image are combined. There is a problem that the background portion of the form image is printed against the user's intention at the overlapped portion.

  In addition, the background portion should originally be transparent because it should not affect the image quality of the graphic portion in the composite image. However, since the background portion of the form image is opaque in the copying apparatus described in Patent Document 2, if the document image data is combined with the form image data by addition processing, the form image of the combined image In a portion where the background portion and the graphic portion in the original image overlap, the color of the graphic portion in the original image is added to the color of the background portion in the form image and printed. That is, in the copying apparatus described in Patent Document 2, when the image data of the document is combined with the image data of the form by addition processing, the background portion of the form image and the graphic portion of the image of the document are included in the combined image. There is a problem that the overlapping portion affects the image quality of the graphic portion of the original image in the background portion of the form image.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can suppress the influence of a background portion in an image before execution of an overlay when executing overlay.

  An image forming apparatus according to the present invention receives an overlay execution unit that executes an overlay for synthesizing document image data and form image data, and specifies a transparent color for at least one of the document image data and the form image data. A transparent color receiving unit, wherein the overlay executing unit treats the transparent color received by the transparent color receiving unit as transparent when the overlay is executed.

  With this configuration, the image forming apparatus according to the present invention can accept designation of a transparent color, which is treated as transparent when executing overlay, for at least one of document image data and form image data. The influence of the background portion in the image of the image can be suppressed more than before when the overlay is executed.

  The image forming apparatus of the present invention further includes background color extracting means for extracting a background color regarded as a background color based on the number of each color existing in the image data, and the transparent color receiving means includes the transparent color receiving means. It is preferable that the background color can be designated as the color.

  With this configuration, the image forming apparatus according to the present invention can specify the automatically extracted background color as a transparent color, so that it can be compared with a configuration in which the automatically extracted background color cannot be specified as a transparent color. , Can improve convenience.

  The image forming apparatus of the present invention further includes a range receiving unit that receives a specification of a color range around the transparent color received by the transparent color receiving unit, and the overlay execution unit includes the range receiving unit. It is preferable to treat the color within the range accepted by as transparent when executing the overlay.

  With this configuration, the image forming apparatus of the present invention can accept the specification of the color range that is treated as transparent when the overlay is executed, so that the influence of the background portion in the image before the execution of the overlay can be further suppressed. .

  An image processing program according to the present invention receives an overlay execution means for executing an overlay for synthesizing original image data and form image data, and designation of a transparent color for at least one of the original image data and the form image data. A computer is made to function as a transparent color receiving means, and the overlay execution means treats the transparent color received by the transparent color receiving means as transparent when the overlay is executed.

  With this configuration, the computer that executes the image processing program of the present invention can accept the designation of the transparent color that is treated as transparent when the overlay is executed for at least one of the image data of the document and the image data of the form. The influence of the background portion on the image before the overlay is executed can be suppressed more than before when the overlay is executed.

  The image forming apparatus according to the present invention can suppress the influence of the background portion in the image before the overlay is performed when the overlay is performed.

1 is a block diagram of a multifunction peripheral according to an embodiment of the present invention. It is a figure which shows the overlay printing method setting screen displayed on the display part shown in FIG. 2 is a flowchart of the operation of the multifunction machine shown in FIG. It is a histogram created by the control part shown in FIG. It is a flowchart of the overlay process performed by the control part shown in FIG. (A) is a figure which shows the example of the image of the form before a synthesis | combination by the control part shown in FIG. FIG. 2B is a diagram illustrating an example of an image of a document before composition by the control unit illustrated in FIG. FIG. 6C is a diagram illustrating an image after the control unit combines the image of the form illustrated in FIG. 6A and the image of the document illustrated in FIG. (A) is a figure which shows the example different from the example shown to Fig.6 (a) of the image of the form before the synthesis | combination by the control part shown in FIG. FIG. 6B is a diagram illustrating an example different from the example illustrated in FIG. 6B of the image of the document before being combined by the control unit illustrated in FIG. FIG. 7C is a diagram illustrating an image after the control unit combines the image of the form illustrated in FIG. 7A and the image of the document illustrated in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, the configuration of a multifunction peripheral as an image forming apparatus according to the present embodiment will be described.

  FIG. 1 is a block diagram of a multifunction machine 10 according to the present embodiment.

  As shown in FIG. 1, the multifunction machine 10 is illustrated with a control unit 11 for controlling the entire multifunction machine 10, a storage unit 12 for storing various data, and various operations input by a user. An operation unit 13 on the operation panel, a display unit 14 on the operation panel for displaying various information, a printer unit 15 for executing printing on paper, and a scanner which is a reading device for reading an original and generating image data And a communication unit 17 that communicates with an external device (not shown) such as a PC (Personal Computer).

  The control unit 11 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a program including the image processing program of the present invention and various data, and a RAM that is used as a work area of the CPU. (Random Access Memory). The CPU is an arithmetic processing unit that operates the control unit 11 by executing a program stored in the ROM. The RAM temporarily stores programs and various data when the programs are executed by the CPU.

  As will be described later, the control unit 11 executes the image processing program, and as will be described later, a transparent color accepting unit 11a that accepts designation of a transparent color for at least one of document image data and form image data, and transparent color acceptance A range accepting unit 11b for accepting designation of a color range around the transparent color accepted by the unit 11a, and a background color extracting unit for extracting a background color regarded as a background color based on the number of each color in the image data 11c, and overlay execution means 11d for executing overlay for combining the image data of the document and the image data of the form.

  The storage unit 12 includes a storage device such as a RAM, an EEPROM (Electrically Erasable Programmable Read Only Memory), and a HDD (Hard Disk Drive).

  The operation unit 13 includes input devices such as buttons that form a touch panel together with the display unit 14 and buttons on the operation panel.

  The display unit 14 is configured by a display device such as an LCD (Liquid Crystal Display).

  The printer unit 15 is a printing device that prints various jobs such as a print data job received from an external apparatus and an image data job generated by the scanner unit 16.

  The communication unit 17 is a communication device that communicates with an external device via a network (not shown) such as a LAN (Local Area Network). For example, the communication unit 17 receives print data to be printed by the printer unit 15 from an external device, and transmits image data generated by the scanner unit 16 to an external device.

  Next, the operation of the multifunction machine 10 will be described.

  FIG. 2 is a diagram showing an overlay printing method setting screen displayed on the display unit 14.

  The control unit 11 of the multifunction machine 10 causes the display unit 14 to display the overlay printing method setting screen illustrated in FIG. 2 when instructed by the user via the operation unit 13 to perform various settings related to overlay.

  The overlay printing method setting screen shown in FIG. 2 includes a form data box 41, which is a box for the user to specify the address of the form image data, and the back side of the form image data and the document image data. A back side box 42 which is a drop-down list box for designating image data of the image, and a composition method box 43 which is a drop-down list box for the user to designate a composition method of form image data and document image data. A document transmittance slider 44 that is a slider for the user to specify the transmittance for image data of the document, and a document that is a drop-down list box for the user to specify the transmission color in the image data of the document The transparent color box 45 and the user can select the transparent color in the image data of the original R User specified color R value box 46a, document specified color G value box 46b, document specified color B value box 46c, which are text boxes for specifically specifying B value R value, G value, and B value; Is a threshold slider 47 which is a slider for designating a color range around the translucent color in the image data of the document, and a form transmissivity slider which is a slider for the user to designate the transmissivity for the form image data 48, a form transparent color box 49, which is a drop-down list box for the user to specify a transparent color in the form image data, and the R color and RGB values of the transparent color in the form image data. , A form designated color R value box 50a and a form designated color G value box 50, which are text boxes specifically designated by B values. Includes a form specified color B value box 50c, and a threshold slider 51 is a slider for a user to specify the range of colors around the transparent color in the image data of the form.

  The user can input the address of the form image data in the form data box 41 via the operation unit 13. The user receives not only the address of the form image data stored in the storage unit 12 but also the address of the form image data stored in an external device connected to the multifunction machine 10 via the communication unit 17. Can be entered. When the address is input to the form data box 41, the control unit 11 stores the input address in the storage unit 12.

  The user can select image data on the back side (destination side) from among the image data of the form and the image data of the original by using the back side box 42 via the operation unit 13. The item that can be selected by the back side box 42 is either “form image data” or “original image data”. Of the form image data and the document image data, the one not selected by the back side box 42 is the front side (source side) image data. When any image data is selected by the back side box 42, the control unit 11 causes the storage unit 12 to store that the selected image data is the back side image data.

  The user can select a synthesis method of the form image data and the document image data by the synthesis method box 43 via the operation unit 13. Composition methods that can be selected by the composition method box 43 are “opaque composition (overwriting) (CMY)”, “translucent addition (CMY)”, “translucent subtraction (CMY)”, “comparison (bright)”, One of “Comparison (dark)” and “Translucent composition”. “Opaque composition (overwriting) (CMY)” means that the image data on the front side is synthesized with the image data on the back side by overwriting in the CMY color space. “Semi-transparent addition (CMY)” means that the image data on the front side obtained by multiplying the image data on the back side multiplied by the transmittance for image data on the back side is multiplied by the transmittance for image data on the front side. In the color space, it means that they are combined by an addition process. “Semi-transparent subtraction (CMY)” means that the image data on the front side obtained by multiplying the image data on the back side multiplied by the transmittance for the image data on the back side is multiplied by the transmittance for the image data on the front side. This means that the color space is combined by subtraction processing. “Comparison (bright)” means the image data on the back side and the front side so that the brighter one of the pixels of the image data on the back side and the pixels of the front side image data that is the combination partner of the pixels is adopted. This means that the image data is synthesized. “Comparison (dark)” means the image data on the back side and the front side so that the darker one of the pixels of the image data on the back side and the pixels of the image data on the front side that is the combination partner of the pixels is adopted. This means that the image data is synthesized. “Semi-transparent composition” means that the image on the front side is multiplied by the transmittance for the image data on the front side multiplied by the value obtained by subtracting the transmittance for the image data on the front side from 100%. This means that the data is synthesized by addition processing. Note that the synthesis method shown here is an example. The synthesis method that can be selected by the synthesis method box 43 is not limited to the synthesis method shown here. When any synthesis method is selected by the synthesis method box 43, the control unit 11 causes the storage unit 12 to store the selected synthesis method as a synthesis method in the overlay.

  The user can designate the transmittance for the image data of the document by the document transmittance slider 44 via the operation unit 13. The transmittance that can be specified by the document transmittance slider 44 is an integer from 0% to 99%. Note that the control unit 11 automatically designates the document transmittance slider 44 depending on the composition method selected by the composition method box 43. For example, when the composition method selected by the composition method box 43 is “opaque composition (overwriting) (CMY)”, the control unit 11 automatically designates the document transmittance slider 44 as 0%. When the transmittance is designated by the document transmittance slider 44, the control unit 11 stores the designated transmittance in the storage unit 12 as the transmittance for image data of the document.

  The user can select a transparent color in the image data of the document by using the document transparent color box 45 via the operation unit 13. The item that can be selected by the original transparent color box 45 is any one of “none”, “white”, “background color”, and “designated color”. “None” means that there is no transparent color in the image data of the document. “White” means that the transmitted color in the image data of the document is white. “Background color” means that the transparent color in the image data of the document is a background color that is automatically extracted by the multifunction device 10. “Specified color” means that the transparent color in the image data of the document is a color specified by the document specified color R value box 46a, the document specified color G value box 46b, and the document specified color B value box 46c. ing. When any item is selected by the document transmission color box 45, the transparent color receiving unit 11a, which is one of the functions of the control unit 11, selects the transparent color in the image data of the document when the selected item is selected. Is stored in the storage unit 12.

  The user specifically designates the transparent color in the image data of the document as an RGB value by the manuscript designation color R value box 46a, the manuscript designation color G value box 46b, and the manuscript designation color B value box 46c via the operation unit 13. be able to. When the color is designated by the original designated color R value box 46a, the original designated color G value box 46b, and the original designated color B value box 46c, the transparent color receiving means 11a designates the designated color in the image data of the original. The color is stored in the storage unit 12 as a color.

  The user can designate a color range around the transparent color in the image data of the document by using the threshold slider 47 via the operation unit 13. When the threshold specified by the threshold slider 47 is x and the R value, G value, and B value of the transparent color are r, g, and b, the range specified by the threshold slider 47 has an R value of r−x. A color range in which the G value is a value from g−x to g + x and the B value is a value from b−x to b + x. The range designation method shown here is an example. The method of specifying the range is not limited to the method shown here. When the range is specified by the threshold slider 47, the range receiving unit 11b, which is one of the functions of the control unit 11, stores the specified range as a color range around the transparent color in the document image data. Remember me.

  The user can designate the transmittance for the image data of the form by the form transmittance slider 48 via the operation unit 13. The transmittance that can be specified by the foam transmittance slider 48 is an integer from 0% to 99%. The control unit 11 automatically designates the form transmittance slider 48 depending on the composition method selected by the composition method box 43. For example, when the composition method selected by the composition method box 43 is “opaque composition (overwriting) (CMY)”, the control unit 11 automatically designates the form transmittance slider 48 to 0%. When the transmittance is designated by the form transmittance slider 48, the control unit 11 stores the designated transmittance in the storage unit 12 as the transmittance for the image data of the form.

  The user can select a transparent color in the image data of the form by using the form transparent color box 49 via the operation unit 13. The item that can be selected by the form transparent color box 49 is any one of “none”, “white”, “background color”, and “designated color”. “None” means that there is no transparent color in the image data of the form. “White” means that the transmitted color in the image data of the form is white. The “background color” means that the transparent color in the form image data is a background color that is automatically extracted by the multifunction device 10. “Specified color” means that the transparent color in the image data of the form is a color specified by the form specified color R value box 50a, the form specified color G value box 50b, and the form specified color B value box 50c. ing. When any item is selected by the form transparent color box 49, the transparent color accepting unit 11a causes the storage unit 12 to store that the color represented by the selected item is the transparent color in the image data of the form. .

  The user specifically designates the transparent color in the image data of the form as an RGB value by the form designation color R value box 50a, the form designation color G value box 50b, and the form designation color B value box 50c via the operation unit 13. be able to. When the color is designated by the form designated color R value box 50a, the form designated color G value box 50b, and the form designated color B value box 50c, the transparent color receiving means 11a designates the designated color in the image data of the form. The color is stored in the storage unit 12 as a color.

  The user can specify a color range around the transparent color in the image data of the form by the threshold slider 51 via the operation unit 13. When the threshold value specified by the threshold value slider 51 is x and the R value, G value, and B value of the transparent color are r, g, and b, the range specified by the threshold value slider 51 has an R value of r−x. A color range in which the G value is a value from g−x to g + x and the B value is a value from b−x to b + x. The range designation method shown here is an example. The method of specifying the range is not limited to the method shown here. When the range is specified by the threshold slider 51, the range receiving unit 11b causes the storage unit 12 to store the specified range as a color range around the transparent color in the form image data.

  In the above description, the control unit 11 gives various setting instructions regarding the overlay via the operation unit 13 of the multi-function peripheral 10. However, various setting instructions regarding the overlay are externally transmitted via the communication unit 17. It may be performed from a device.

  FIG. 3 is a flowchart of the operation of the multifunction machine 10.

  Upon receiving an overlay instruction from the operation unit 13 or from an external device via the communication unit 17, the control unit 11 starts the process illustrated in FIG.

  As shown in FIG. 3, the control unit 11 acquires form image data based on the address stored in the storage unit 12 (S <b> 101). For example, the form image data may be image data read by the scanner unit 16 and stored in the storage unit 12, or transmitted from an external device via the communication unit 17 and stored in the storage unit 12. The image data may be stored image data, or may be image data stored in an external device.

  Next, the control unit 11 generates image data of the document (S102). For example, when an instruction for overlay is given from the operation unit 13, the control unit 11 may read the original with the scanner unit 16 to generate image data of the original, or the instruction for overlay may be the communication unit 17. The image data of the document may be generated based on the print data transmitted from the external device via the communication unit 17 together with the overlay instruction.

  Next, the background color extracting unit 11c, which is one of the functions of the control unit 11, uses the background color from the form image data acquired by the control unit 11 in S101 and the original image data generated by the control unit 11 in S102. Is extracted (S103). A specific background color extraction method will be described below.

  FIG. 4 is a histogram created by the control unit 11.

  As shown in FIG. 4, the background color extraction unit 11c creates a histogram of RGB values of all pixels of the form image data acquired by the control unit 11 in S101. Then, the background color extracting unit 11c, based on the created histogram, the R value having the highest frequency among the R values of all the pixels, the G value having the highest frequency among the G values of all the pixels, and the B values of all the pixels. Among the values, the color composed of the B value having the highest frequency is extracted as the background color of the form image data. The background color extraction unit 11c may create a histogram of the RGB values of all the pixels of the form image data. However, the background color extracting unit 11c may extract the pixels extracted from all the pixels of the form image data according to a predetermined rule such as a predetermined interval. If a histogram of RGB values is created, it is possible to reduce the storage capacity required for the processing and improve the processing speed of S103. The form image data acquired by the control unit 11 in S101 has been described above. However, the background color extracting unit 11c similarly extracts the background color from the document image data generated by the control unit 11 in S102. The background color extracting unit 11c extracts the background color for each page when the image data is composed of a plurality of pages.

  As shown in FIG. 3, when the background color extracting unit 11c finishes the process of S103, the overlay execution unit 11d, which is one of the functions of the control unit 11, executes the overlay process shown in FIG. 5 (S104).

  FIG. 5 is a flowchart of overlay processing executed by the control unit 11.

  As shown in FIG. 5, the overlay execution unit 11d acquires the transparent color stored in the storage unit 12 for each of the document image data and the form image data (S151). Here, when the transmission color stored in the storage unit 12 is “None”, the overlay execution unit 11d does not acquire anything as the transmission color, and the transmission color stored in the storage unit 12 is “white”. If the transmission color is white and the transmission color stored in the storage unit 12 is “background color”, the background color extracted in S103 is acquired as the transmission color and stored in the storage unit 12. When the transmitted color that has been set is “specified color”, the specified color stored in the storage unit 12 is acquired as the transmitted color.

  Next, the overlay execution unit 11d treats each of the image data of the document and the image data of the form as a transparent color in the range stored in the storage unit 12 among the surrounding colors of the transparent color acquired in S151. (S152).

  Next, the overlay execution unit 11d acquires a color to be handled as transparent according to the composition method stored in the storage unit 12 (S153). For example, when the compositing method is addition processing in a CMY color space, white whose C value, M value, and Y value are all 0 behaves in the same way as a transparent color at the time of compositing. It is judged as. The color to be treated as transparent according to the synthesis method is stored in advance in the storage unit 12 in association with the synthesis method.

  Next, the overlay execution unit 11d reads out pixels to be combined one by one from the document image data and the form image data (S154).

  Next, the overlay execution unit 11d determines whether or not the color of the front side pixel out of the two pixels read out in S154 is a color handled as transparent (S155). Here, when it is stored in the storage unit 12 that the image data of the document is the image data on the back side, the overlay execution unit 11d determines the pixel of the form as the pixel on the front side and stores the form data in the storage unit 12 Is stored as image data on the back side, the pixel of the document is determined as the pixel on the front side. Further, the color treated as transparent is the color acquired in S151, S152, and S153.

  If the overlay execution unit 11d determines in S155 that the color of the front side pixel out of the two pixels read out in S154 is not a color that is treated as transparent, the color of the back side pixel in the two pixels read out in S154 is It is determined whether the color is handled as transparent (S156). Here, when the storage unit 12 stores that the image data of the document is the back side image data, the overlay execution unit 11d determines the pixel of the document as the back side pixel and stores the form data in the storage unit 12. If the image data is stored on the back side, the pixel of the form is determined as the back side pixel. Further, the color treated as transparent is the color acquired in S151, S152, and S153.

  If the overlay execution unit 11d determines in S155 that the color of the front-side pixel among the two pixels read out in S154 is a color that is treated as transparent, the overlay execution unit 11d performs the same processing as in S156, out of the two pixels read out in S154. It is determined whether or not the color of the pixel on the back side is a color handled as transparent (S157).

  If the overlay execution unit 11d determines in S156 that the color of the pixel on the back side out of the two pixels read out in S154 is not a color that can be treated as transparent, the overlay execution unit 11d combines the two pixels using the combining method stored in the storage unit 12. (S158).

  Next, the overlay execution unit 11d selects one of the attribute information of the two pixels read out in S154 according to the combining method stored in the storage unit 12, and selects the selected attribute information of the combined pixel. The attribute information is set (S159). Here, the attribute information is information set in the image data for each pixel so that the image is appropriately printed. Examples of attribute information include, but are not limited to, photographs, graphics, and text. Note that the method of selecting attribute information in S159 depends on the design. For example, if the combining method is “comparison (bright)”, the overlay execution unit 11d selects bright pixel attribute information from the two pixel attribute information read in S154. good.

  If the overlay execution unit 11d determines in S156 that the color of the pixel on the back side of the two pixels read in S154 is a color that is treated as transparent, the overlay execution unit 11d determines that the color on the front side is based on the transmittance stored in the storage unit 12. The pixel is made translucent, and this pixel is set as a synthesized pixel (S160).

  Next, the overlay execution unit 11d sets the attribute information of the front-side pixel among the attribute information of the two pixels read in S154 as the attribute information of the combined pixel (S161).

  If the overlay execution unit 11d determines in S157 that the color of the pixel on the back side out of the two pixels read out in S154 is not a color to be treated as transparent, the overlay execution unit 11d determines that the color on the back side is based on the transmittance stored in the storage unit 12. The pixel is made translucent, and this pixel is set as a synthesized pixel (S162).

  Next, the overlay execution unit 11d sets the attribute information of the pixel on the back side among the attribute information of the two pixels read in S154 as the attribute information of the combined pixel (S163).

  If the overlay execution unit 11d determines in S157 that the color of the pixel on the back side of the two pixels read in S154 is a color that is treated as transparent, it sets white as the combined pixel (S164).

  Next, the overlay execution unit 11d sets the attribute information of the combined pixel as none (S165).

  When the overlay execution unit 11d completes the processes of S159, S161, S163, and S165, it determines whether or not the synthesis of all the pixels of the document image data and the form image data is completed (S166).

  If the overlay execution unit 11d determines in S166 that the synthesis of all the pixels of the document image data and the form image data has not been completed, the overlay execution unit 11d executes the process of S154 again for the remaining pixels. On the other hand, if the overlay execution unit 11d determines in S166 that the synthesis of all the pixels of the document image data and the form image data has been completed, the overlay processing shown in FIG.

  As shown in FIG. 3, when the overlay process in S104 is completed, the control unit 11 performs a color conversion process based on the combined image data in the overlay process in S104 and its attribute information (S105). For example, in this color conversion process, image data is converted from RGB to CMYK, which is a toner color, and at that time, black pixels whose attribute information is graphic are converted into CMY mixed colors, and attribute information is displayed. It is also possible to convert black pixels whose text is text only to K.

  Next, the control unit 11 performs halftone processing based on the image data subjected to the color conversion processing in S105 and the attribute information (S106). For example, the image data may be configured such that high-resolution halftone processing is performed on pixels whose attribute information is text.

  Finally, the control unit 11 causes the printer unit 15 to execute printing based on the image data that has been subjected to the halftone process in S106 (S107), and ends the process illustrated in FIG.

  As described above, the multifunction machine 10 receives the designation of the transparent color, which is handled as transparent by the overlay execution unit 11d when executing the overlay, by the transparent color reception unit 11a for the document image data and the form image data. Therefore, the influence of the background portion in the image before the overlay is performed can be suppressed more than before when the overlay is performed.

  FIG. 6A is a diagram illustrating an example of a form image before composition by the control unit 11. FIG. 6B is a diagram illustrating an example of an image of a document before being combined by the control unit 11. FIG. 6C is a diagram illustrating an image after the control unit 11 combines the form image illustrated in FIG. 6A and the original image illustrated in FIG.

  The background image of the original image shown in FIG. 6B is gray. The multifunction machine 10 specifies the gray color of the transparent image in the image data of the document shown in FIG. 6B, so that the form image shown in FIG. 6A and the image of the document shown in FIG. Can be combined by the overlay execution means 11d to generate the image shown in FIG. In the image shown in FIG. 6C, the influence of the gray background portion in the original image shown in FIG. 6B is suppressed.

  Note that since the user can specify a transparent color, the multifunction machine 10 can be overlaid as shown in FIG.

  FIG. 7A is a diagram illustrating an example different from the example illustrated in FIG. 6A of the form image before being combined by the control unit 11. FIG. 7B is a diagram illustrating an example different from the example illustrated in FIG. 6B of the image of the document before being combined by the control unit 11. FIG. 7C is a diagram illustrating an image after the control unit 11 combines the form image illustrated in FIG. 7A and the original image illustrated in FIG.

  In the form image shown in FIG. 7A, the graphic portion is white and the background portion is gray. In the conventional overlay, the white portion is treated as the background portion. However, since the user can designate a transparent color in the multifunction machine 10, the transparent color in the image data of the form shown in FIG. 7A is designated as gray instead of white, so that FIG. The form image shown in FIG. 7B and the original image shown in FIG. 7B can be combined by the overlay execution unit 11d to generate the image shown in FIG. 7C. In the image shown in FIG. 7C, the white portion in the form image shown in FIG. 7A is not treated as the background portion but appears correctly as the graphic portion.

  The multi-function device 10 can allow the user to specifically specify the transmitted color by the color value. However, in general, it is difficult for the user to specify the color value of the background portion accurately. The multi-function device 10 can designate the background color automatically extracted by the background color extraction unit 11c as the transmission color by the transmission color receiving unit 11a. Therefore, the multifunction device 10 can improve convenience compared to a configuration in which the background color that is automatically extracted cannot be designated as a transparent color.

  For example, when a document of a plurality of pages is read by the scanner unit 16, the color of the background portion in the read image may vary depending on the page. In the multifunction machine 10, since the background color extracting unit 11c extracts the background color for each page, when the background color is designated as the transparent color by the transparent color receiving unit 11a, the transparent color suitable for each page is executed when the overlay is executed. Color is applied automatically. Therefore, the multifunction machine 10 can improve the image quality of the combined image and the convenience as compared with the configuration in which the background color extraction unit 11c does not extract the background color for each page.

  When a document is read by the scanner unit 16, the color of the background portion in the read image may be spread over a certain range instead of a single color. The multifunction device 10 can accept the specification of the color range treated as transparent by the overlay execution unit 11d when the overlay is executed by the range reception unit 11b, and thus further suppress the influence of the background portion in the image before the execution of the overlay. be able to.

  As described above, the MFP 10 determines which of the image data of the document and the image data of the form is to be used as the image data on the back side, the method of combining the image data of the document and the image data of the form, Since the user can make various settings related to the overlay, such as the transparent color, the overlay desired by the user can be executed.

  Also, the multifunction machine 10 combines the transparent color pixel in the document image data and the opaque pixel in the form image data, the transparent color pixel in the form image data, and the opaque image data in the document image data. When color conversion processing or halftone processing is performed on a pixel that is combined with a new pixel, color conversion processing or halftone processing is performed using pixel attribute information that was opaque in the original image data, so the image quality of the original image data Can be maintained.

  The image forming apparatus according to the present invention has been described with respect to a multifunction peripheral in the present embodiment, but may be an image forming apparatus other than the multifunction peripheral, such as a copier or a printer.

  In addition, the image processing program of the present invention is executed by a multi-function peripheral which is an image forming apparatus in the present embodiment, but is executed by a computer other than the image forming apparatus such as a PC. May be.

10 MFP (image forming device)
11a Transmission color reception means 11b Range reception means 11c Background color extraction means 11d Overlay execution means

Claims (4)

Overlay execution means for executing overlay for combining original image data and form image data; and transparent color acceptance means for accepting designation of a transparent color for at least one of original image data and form image data. And
The image forming apparatus according to claim 1, wherein the overlay execution unit treats the transparent color received by the transparent color reception unit as transparent when the overlay is executed. A background color extracting means for extracting a background color regarded as a color of a background portion based on the number of each color existing in the image data;
The image forming apparatus according to claim 1, wherein the transparent color accepting unit can designate the background color as the transparent color. A range receiving unit for receiving designation of a color range around the transparent color received by the transparent color receiving unit;
The image forming apparatus according to claim 1, wherein the overlay execution unit treats a color within the range received by the range reception unit as transparent when the overlay is executed. The computer functions as an overlay execution unit that executes overlay for combining the image data of the document and the image data of the form, and a transparent color reception unit that receives designation of a transparent color for at least one of the image data of the document and the image data of the form Let
The image processing program characterized in that the overlay execution means treats the transparent color received by the transparent color reception means as transparent when the overlay is executed.