JP2013162434A - Image forming apparatus and image output method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a user to determine a color character part easily when a color image is output monochromatically, even if a color character part is emphasized and output monochromatically.SOLUTION: An image forming apparatus 1 includes a color value detection unit 2 for detecting the color value of each pixel included in color image data, a character extraction unit 4a for extracting a character part from the color image data, a character color determination unit 4b for determining whether or not the character color of a character part is a predetermined color on the basis of the color value of a pixel corresponding to the character part thus extracted, a character decoration addition unit 3a for performing monochrome conversion of a character part determined to be a predetermined color by the character color determination unit 4b, and adding a character decoration to the character part after monochrome conversion, and a print unit 12 for outputting monochrome image data including the character part to which a character decoration is added by the character decoration addition unit 3a.

Description

  The present invention relates to an image forming apparatus and an image output method, and more particularly to an image forming apparatus capable of monochrome output of color image data and an image output method using the apparatus.

  In an information processing apparatus such as a PC (personal computer), various types of application software for performing document creation, spreadsheet, and the like are used. In recent years, color display has become common, and various types of data created by these application software are also displayed in color, which greatly improves the visibility of data and the usability of users.

  In addition, color printers having a function of color printing a color image output from a PC or a color image read by a scanner have become widespread. Signals normally input from a PC or scanner are R (red), G (green), and B (blue) signals. These R, G, and B signals are Y (yellow), M (magenta), and C in a color printer. It is converted into (cyan) and K (black) signals and printed out.

  In such a color printer, color image data is converted into monochrome image data and output in order to save color toner. For example, assume that a color text original is to be copied in monochrome. In the case of text manuscripts, the text part to be emphasized is often colored in red or the like, but since it is converted to grayscale by monochrome conversion, the color text part is lighter than the surrounding text. Will be. For this reason, there has been a problem that it becomes difficult to recognize a character portion to be originally emphasized.

  On the other hand, for example, Patent Document 1 describes a copying machine that outputs a predetermined color in a document image in black and white with a predetermined density. According to this, the hue value is detected from the color image, and it is determined whether or not the detected hue value is within a predetermined range. If the hue value is within a predetermined range, an area corresponding to the hue value (predetermined color) is output in monochrome at a predetermined density. If the hue value is outside the predetermined range, the hue value (predetermined An area corresponding to a color other than the color is output in monochrome at an arbitrarily set density.

JP-A-6-70182

  However, in the copying machine described in Patent Document 1, when density adjustment is performed on a predetermined color area, density adjustment performed on a color area other than the predetermined color is performed on the predetermined color area. By disabling, the user can obtain the desired output image. When a color original is copied in black and white, the color part to be emphasized and the other part are expressed only by the difference in density. Will be. For this reason, it is difficult for the user to say that the difference between the colors can be sufficiently determined.

  Also, for example, when making a black-and-white copy of a character document that consists mostly of black characters and some of the color characters you want to emphasize, distinguish the color difference between black characters and color characters based on the difference in density. In order to be able to do so, the density of the color characters may be output at a density lower than that of black. In such a case, there has been a problem that the original emphasis purpose cannot be achieved and the printed matter becomes difficult to see from the user's point of view.

  The present invention has been made in view of the above-described circumstances. When a color image is output in monochrome, the color character portion is emphasized, and even if the color image is output in monochrome, the user can It is an object of the present invention to provide an image forming apparatus that can be easily discriminated and an image output method using the apparatus.

  A first technical means of the present invention for solving the above-described problem is an image forming apparatus that outputs color image data in monochrome, and detects a color value of each pixel included in the color image data. A character extraction unit that extracts a character part from the color image data, and determines whether the character color of the character part is a predetermined color based on a color value of a pixel corresponding to the extracted character part A character color determination unit; and a character modification addition unit that performs monochrome conversion on a character part determined to be a predetermined color by the character color determination unit and adds character modification to the character part after the monochrome conversion. Monochrome image data including a character part to which character modification is added by the part is output.

  The second technical means includes a character modification table in which the color value of the predetermined color and character modification are registered in association with each other in the first technical means, and the character modification adding unit is predetermined by the character color determining unit. Character modification of the character portion determined to be a color is specified from the character modification table, and the specified character modification is added.

  According to a third technical means, in the first or second technical means, the color value is a CMYK value, and the character modification adding unit is configured to detect a character portion determined to be a predetermined color by the character color determining unit. The smaller the value of K is, the higher the density of the character portion after monochrome conversion is increased.

  According to a fourth technical means, in any one of the first to third technical means, the character modification is any one or more of bold, italic, underline, encircling, shaded, and enlarged. It is what.

  According to a fifth technical means, in any one of the first to fourth technical means, the predetermined color is a color other than black.

  A sixth technical means is an image output method by an image forming apparatus for monochrome output of color image data, wherein the image forming apparatus detects a color value of each pixel included in the color image data. A character extraction step for extracting a character portion from the color image data, and whether the character color of the character portion is a predetermined color based on a color value of a pixel corresponding to the character portion extracted in the character extraction step A character color determination step for determining whether or not the character portion determined to be a predetermined color in the character color determination step is subjected to monochrome conversion, and character modification is added to the character portion after the monochrome conversion; And an image output step for outputting monochrome image data including the character portion to which the character modification is added in the character modification adding step.

  According to the present invention, when a color image is output in black and white, character modification such as bold or underline can be effectively added to the color character portion, so that even when output in monochrome. The user can easily determine the color character portion.

1 is a block diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows an example of a character modification table. It is a figure which shows an example of a character modification table. It is a figure which shows the output example of the monochrome image data printed out by the printing part. It is a flowchart for demonstrating an example of the image output method by the image forming apparatus of this invention. FIG. 6 is a flowchart for explaining an example of an image output method by the image forming apparatus of the present invention, and is a continuation of FIG. FIG. 7 is a flowchart for explaining an example of an image output method by the image forming apparatus of the present invention, and is a continuation of FIG. 6.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an image forming apparatus and an image output method using the apparatus will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. In the figure, 1 denotes the image forming apparatus. The image forming apparatus 1 supports both monochrome printing and color printing, and can be exemplified as a digital multifunction peripheral (MFP) having a copy function, a printer function, a facsimile function, and a scanner function, for example. The image forming apparatus 1 is connected to an information processing apparatus (hereinafter referred to as a PC) 20 via a network N.

  The image forming apparatus 1 includes a color value detection unit 2, an image processing unit 3, a main control unit 4, a storage unit 5, an input control unit 6, a LAN (Local Area Network) I / F (Interface) 7, a scanner unit 8, an operation Unit 9, output control unit 10, display unit 11, and printing unit 12. In addition, a printer driver 21 for controlling the operation of the image forming apparatus 1 is installed in the PC 20. The printer driver 21 is activated when the image data created by the PC 20 is printed, and is printed out by the image forming apparatus 1. be able to.

  In FIG. 1, the main control unit 4 includes a CPU and a memory (ROM, RAM, etc.) for controlling the operation of each unit of the image forming apparatus 1. The ROM stores a control program for controlling the operation of the image forming apparatus 1, and the CPU reads the control program from the ROM to the RAM and executes it when the control program is executed. The storage unit 5 includes, for example, an HDD (Hard Disk Drive), a semiconductor memory, and the like, and stores image data input to the image forming apparatus 1 and the like.

  The input control unit 6 is connected to the LAN I / F 7, the scanner unit 8, and the operation unit 9, and controls the operations of these units. The LAN I / F 7 inputs image data from the PC 20 via the network N. The image data from the PC 20 is document data created by predetermined application software for performing document creation, spreadsheet, etc., and is input as RGB signals. The scanner unit 8 optically reads a document (printed material) and inputs image data of the read document. Image data from the scanner unit 8 is input as RGB signals. The operation unit 9 includes an operation key group for receiving an operation input from a user, a touch panel, and the like. The operation unit 9 includes a monochrome copy start key and a color copy start key.

  The image processing unit 3 performs various types of image processing on the image data input from the scanner unit 8 or the PC 20. As an example of image processing, the image processing unit 3 converts RGB image data input from the scanner unit 8 or the PC 20 into CMYK image data that can be printed out. The image data converted into CMYK by the image processing unit 3 is sent to the printing unit 12, and the printing unit 12 performs monochrome printing or color printing on the CMYK image data. When the image data input from the scanner unit 8 or the PC 20 is color image data, the image processing unit 3 converts the color image data into monochrome image data when the monochrome copy start key of the operation unit 9 is pressed. Perform the conversion process.

  The output control unit 10 is connected to the LAN I / F 7, the display unit 11, and the printing unit 12, and controls the operations of these units. The LAN I / F 7 transmits the image data read by the scanner unit 8 or the image data stored in the storage unit 5 to the external device via the network N. The display unit 11 includes, for example, a liquid crystal display integrated with a touch panel, and performs various information display, image data preview display, and the like. The printing unit 12 performs monochrome printing or color printing on the image data processed by the image processing unit 3.

  A main object of the present invention is to enhance a color character portion when a color image is output in monochrome, so that the user can easily determine the color character portion even in monochrome output. As a configuration for this, the image forming apparatus 1 detects an image input unit that inputs color image data, and a color value (also referred to as a color value) of each pixel included in the color image data input from the image input unit. A color value detection unit 2, a character extraction unit 4a that extracts a character part from color image data, and whether or not the character color of the character part is a predetermined color based on the color value of a pixel corresponding to the extracted character part. A character color determination unit 4b for determining, a character modification adding unit 3a for converting a character part determined to be a predetermined color by the character color determination unit 4b into monochrome, and adding character modification to the character part after the monochrome conversion, and character modification addition And an image output unit that outputs monochrome image data including a character portion to which character modification is added by the unit 3a.

  In the above description, the image input unit corresponds to the scanner unit 8 and the LAN I / F 7 and may input color image data obtained by reading a color original with the scanner unit 8 or a color image acquired from the PC 20 via the LAN I / F 7. Image data may be input. The image output unit corresponds to the LAN I / F 7, the display unit 11, and the printing unit 12. The LAN I / F 7 transmits the monochrome image data after the color image data is converted into monochrome to an external device. The display unit 11 displays monochrome image data after the color image data is converted into monochrome. The printing unit 12 prints monochrome image data after the color image data is subjected to monochrome conversion.

  First, as a first example, a case of a copy process for performing a monochrome copy of a color original will be described. When a user sets a color document at a predetermined document reading position of the image forming apparatus 1 and presses a monochrome copy start key (not shown) of the operation unit 9, the scanner unit 8 reads the color document to read RGB color images. Data is entered. The RGB color image data input by the scanner unit 8 is converted into CMYK color image data by the image processing unit 3. Then, the color value detection unit 2 detects the color value of each pixel included in the color image data converted into CMYK by the image processing unit 3. Here, as exemplified in the character modification table of FIG. 2, the color value is a percentage (0 to 100) of CMYK constituting each color. For example, red is shown in FIG. Corresponding to the color “1”, C = 0, M = 100, Y = 100, and K = 0. The pure yellow color corresponds to the color “5” in FIG. 2 and is indicated by C = 0, M = 0, Y = 100, and K = 0.

  The character extraction unit 4a is realized as a function of the main control unit 4 and extracts a character portion from color image data. Since the color image data in this example is read by the scanner unit 8, the character portion cannot be extracted as character data (character code) as it is. For this reason, for example, a known OCR (Optical Character Recognition / Reader) process is performed on the color image data to perform character recognition. Thereby, the character extraction part 4a can extract a character part as character data from color image data. In addition, since OCR is a well-known technique, description here is abbreviate | omitted.

  The character color determination unit 4b is realized as one function of the main control unit 4, and whether or not the character color of the character part is a predetermined color based on the color value of the pixel corresponding to the character part extracted by the character extraction unit 4a. Determine whether. The determination as to whether or not the color is a predetermined color is, for example, a color value (CMYK value) of a pixel corresponding to a character part is a black color value, specifically, C = 0, M = 0, Y = 0. , K = 100, C = 100, M = 100, Y = 100, K = 0, or other color values. That is, a color other than black is determined as the predetermined color. In this case, color values of colors other than black may be registered in advance in the character modification table 5a of FIG. The character color determination unit 4b determines that the character color of the character part is a predetermined color when the color value of the pixel corresponding to the character part extracted by the character extraction unit 4a is registered in the character modification table 5a. can do.

  The character modification table 5a in FIG. 2 is a table in which color values (CMYK values) of predetermined colors and character modification patterns (including character modification and character density) are registered in association with each other and stored in the storage unit 5 in advance. It is assumed that Here, character modification is, for example, bold to make a character thick, italic to make the character slant, underline to underline the character, enclosing line to enclose the character, shading to shade the character, enlargement to enlarge the character Either one or a combination of these two or more.

  Next, the character modification adding unit 3a is realized as a function of the image processing unit 3. The character part determined to be a predetermined color by the character color determination unit 4b is converted into monochrome, and the character modification is performed on the character part after monochrome conversion. Append. Specifically, the character modification adding unit 3a identifies the character modification of the character portion determined as the predetermined color by the character color determining unit 4b from the character modification table 5a, and adds the specified character modification. As illustrated in FIG. 3, character modification patterns are assigned to the character modification table 5a according to the range of color values of CMYK. The example of the character modification table in FIG. 3 is the same as the character modification table in FIG. 2, and shows the character modification pattern in association with each color range of CMYK.

  In the example of FIG. 3, when the CMY color value (%) of the character portion falls within the range of C = 0 to 25, M = 76 to 100, and Y = 76 to 100, this character portion is determined to be a predetermined color. As a pattern for character modification 1, bold and underline are added to the character portion. Further, when the CMY color value (%) of the character portion falls within the range of C = 0 to 25, M = 51 to 75, and Y = 76 to 100, this character portion is determined to be a predetermined color and character modification 2 As a pattern, a bold character and a surrounding line are added to the character part. Here, in order to simplify the description, only two character modification patterns are illustrated, but it is assumed that the character modification patterns are assigned in advance according to the CMY color value range of the character portion of a predetermined color.

  Further, it is desirable that the character modification adding unit 3a increase the density of the character portion after monochrome conversion as the K value of the character portion determined to be the predetermined color by the character color determining unit 4b is smaller. Specifically, as illustrated in FIG. 3, when the K color value (%) of the character portion is 0 to 25, the character portion density is 100%, and when 26 to 50, the density is 80%. In the case of 51 to 75, the concentration is 60%, and in the case of 76 to 100, the concentration is 40%. For example, when the character portion is red, it corresponds to the color “1” in FIG. 2 and is indicated by C = 0, M = 100, Y = 100, and K = 0. Accordingly, bold characters and underlines are added to the red character portion as a character modification 1 pattern, and the density is converted to 100%.

  The printing unit 12 prints and outputs monochrome image data including the character portion to which the character modification is added by the character modification adding unit 3a. In the above example, character modification patterns are assigned according to the range of CMYK color values. However, the same processing is applied to the range of RGB color values (0 to 255) in color image data before CMYK conversion. It can be carried out. In this case, a character modification table to which character modification patterns are assigned according to the range of RGB color values (0 to 255) may be provided.

  FIG. 4 is a diagram illustrating an output example of monochrome image data printed out by the printing unit 12. In the color original 30 shown in FIG. 4A, a character portion corresponding to “Safety Precautions” is configured as a color character portion 31, and the other character portions are configured with black characters. When the color original 30 is copied in monochrome by a conventional method, a printed matter 40 as shown in FIG. 4B is printed out. Since the density of the character portion 41 corresponding to the “safety precautions” of the printed matter 40 is converted to gray scale, it becomes lighter than the density of black characters in other portions.

  On the other hand, when the color original 30 is black and white copied by the image output method of the present invention, it corresponds to the color value (CMYK value) of the color character portion 31 corresponding to the “safety precautions” of the color original 30. For example, the printed matter 50 shown in FIG. 4C or the printed matter 60 shown in FIG. 4D is printed out. The character portion 51 corresponding to the “Safety Precautions” of the printed matter 50 shows an example in which a pattern of character modification 1 is added. As the character modification, bold and underline are added, and further printed out at a density of 100%. Has been. Further, the character portion 61 corresponding to “Safety Precautions” of the printed material 60 shows an example in which a pattern of character modification 2 is added. As the character modification, bold and encircled lines are added, and the density is 100%. Is printed out.

  Next, as a second example, a case of data transmission processing in which monochrome image data obtained by scanning a color original is transmitted to an external device by e-mail or facsimile will be described. When a user places a color document at a predetermined document reading position of the image forming apparatus 1 and presses a monochrome scan start key (not shown) of the operation unit 9, the scanner unit 8 causes the color document to be scanned in the same manner as in the copy process. RGB color image data is input. The RGB color image data input by the scanner unit 8 is converted into CMYK color image data by the image processing unit 3. Thereafter, in the same manner as in the case of the copy process, monochrome image data including a character portion to which character modification is added by the character modification adding unit 3a is generated.

  In the case of data transmission processing, the monochrome image data is transmitted to a predetermined external device via the LAN I / F 7 by e-mail or facsimile (Internet FAX). The monochrome image data may be stored in the storage unit 5 built in the image forming apparatus 1 or an external recording medium (USB memory or the like) that can be connected to the image forming apparatus 1.

  Next, as a third example, a case of print processing for monochrome printing of color image data input from the PC 20 will be described. The user creates color image data using predetermined application software (document creation software, spreadsheet software, etc.) installed in the PC 20. In the color image data in this case, the character portion is configured as character data instead of image data. The user activates the printer driver 21 of the PC 20 and designates monochrome printing with the printer driver 21 in order to perform monochrome printing of the color image data with the image forming apparatus 1. Send to.

  In the image forming apparatus 1, RGB color image data input from the PC 20 is converted into CMYK color image data by the image processing unit 3, as in the case of copy processing. Then, the color value detection unit 2 detects the color value of each pixel included in the color image data converted into CMYK by the image processing unit 3. Next, the character extraction unit 4a extracts a character part from the color image data. However, in the case of the color image data of this example, the character part is configured as character data as described above, so it is necessary to perform OCR processing. Absent. Although it is conceivable that color image data in which the character portion is configured as image data is input from the PC 20, in such a case, character recognition is performed by performing OCR processing as in the case of copy processing. It is desirable.

  Thereafter, in the same manner as in the case of the copy process, monochrome image data including a character portion to which character modification is added by the character modification adding unit 3a is generated. The printing unit 12 prints and outputs monochrome image data including the character portion to which the character modification is added by the character modification adding unit 3a.

  In the first to third examples described above, that is, monochrome image data including a character portion to which character modification is added by the character modification addition unit 3a before monochrome output, copy output, data transmission, and print output is displayed. 11 may be displayed as a preview. Thereby, since the user can confirm the conversion result in advance, a copy error, a data transmission error, a print error, and the like can be prevented.

  In this way, when a color image is output in black and white, it can be effectively emphasized by adding character modifications such as bold and underline to the color character portion. Can easily distinguish the character portion of the color. Also, in the case of a color document that includes character parts that are displayed in color for emphasis, the user can easily determine the color character parts by character modification without outputting the color document as it is. However, the same effect as color output can be obtained. As a result, relatively expensive color toner can be saved in the case of copying and printing, and when storing the image data after monochrome conversion, it is not monochrome data but color data. Since the data is stored, the data capacity is reduced, and the capacity of the storage medium can be saved.

  5 to 7 are flowcharts for explaining an example of an image output method by the image forming apparatus 1 of the present invention. 6 is a continuation of FIG. 5, and FIG. 7 is a continuation of FIG. In this example, a case of a copy process for monochrome copying a predetermined document will be described. In the character modification table 5a, as shown in FIG. 3, as CMY color values (%) of predetermined colors, ranges of C = 0 to 25, M = 76 to 100, Y = 76 to 100, The ranges of C = 0 to 25, M = 51 to 75, and Y = 76 to 100 are registered, and the pattern of character modification 1 (bold, underline) and the pattern of character modification 2 (bold, encircled line) respectively. It is associated. In the character modification table 5a, a range of 0 to 25, a range of 26 to 50, a range of 51 to 75, and a range of 76 to 100 are registered as K color values (%) of a predetermined color. , Density 100%, density 80%, density 60%, and density 40% are associated with each other.

  In FIG. 5, first, the user sets a document at a predetermined document reading position of the image forming apparatus 1. The main control unit 4 of the image forming apparatus 1 determines whether a monochrome copy start key or a color copy start key (not shown) of the operation unit 9 is pressed by the user and a scanning operation is performed (step S1). If it is determined that one of the copy start keys has been pressed and a scanning operation has been performed (YES), the scanner unit 8 starts scanning the document (step S2). If it is determined in step S1 that no copy start key has been pressed and no scanning operation has been performed (NO), a transition is made to a standby state in step S1.

  When the scanner unit 8 starts scanning a document in step S2, RGB image data corresponding to the document is input to the image forming apparatus 1. The RGB image data input by the scanner unit 8 is converted into CMYK image data by the image processing unit 3.

  Next, the main control unit 4 determines whether the document output method is color or monochrome (step S3), and determines that the document output method is color (in the case of color in the figure), FIG. 7 moves to step S20. If it is determined in step S3 that the document output method is monochrome (in the case of monochrome in the figure), the color value detection unit 2 detects the color value (CMYK value) of each pixel of the image data (step S4). ). In step S3, if the user presses the color copy start key of the operation unit 9, the document output method is determined to be color, and the user presses the monochrome copy start key of the operation unit 9. If it is determined, the document output method is determined to be monochrome.

  Next, the main control unit 4 determines whether or not the document read by the scanner unit 8 is a character document including the character part, based on whether or not the character part is extracted from the image data by the character extraction unit 4a. If it is determined that the document is a character document (in the case of YES), the color value (CMYK) of each pixel of the image data detected by the color value detection unit 2 determines whether or not the character document is a monochrome document. (Step S6). If it is determined in step S5 that the document is not a character document (NO), the process proceeds to step S20 in FIG.

  In step S6, when the color value (CMYK value) of each pixel of the image data detected by the color value detection unit 2 indicates black, it is determined that the character document is a monochrome document, and in this case (YES) Case), the process proceeds to step S20 in FIG. In step S6, when the color value (CMYK value) of each pixel of the image data detected by the color value detection unit 2 indicates a color other than black, it is determined that the character document is a color document. (In the case of NO), the character color determination unit 4b determines the color range of each character based on the color value of the pixel corresponding to each character (step S7).

  Next, in FIG. 6, the character color determination unit 4 b determines that the color value (CMY% value) of the character to be determined is a color range registered in the character modification table 5 a, that is, C = 0 to 25 (%). , M = 76 to 100 (%), Y = 76 to 100 (%) is determined whether or not (step S8), and if it is determined to be within the range of step S8 (in the case of YES), characters The modification adding unit 3a refers to the character modification table 5a, and adds a character modification 1 pattern (bold, underline) to the determination target character after monochrome conversion (steps S9 and S12). Further, when it is determined that it does not fall within the range of step S8 (in the case of NO), the color value (CMY% value) of the character to be determined is the color range registered in the character modification table 5a, that is, C = 0. It is determined whether or not it falls within the range of ˜25 (%), M = 51 to 75 (%), and Y = 76 to 100 (%) (step S10).

  In step S10, when it is determined that the character color determination unit 4b falls within the range of step S10 (in the case of YES), the character modification adding unit 3a refers to the character modification table 5a and sets the character to be determined after monochrome conversion. On the other hand, a character modification 2 pattern (bold, encircled line) is added (steps S11 and S12). Moreover, when it determines with not entering into the range of step S10 (in the case of NO), it transfers to step S13. In this example, only two color ranges to be determined for each color are illustrated, but if a color range other than black is registered in the character modification table 5a, determination is made for all registered color ranges. It shall be.

  Next, the character color determination unit 4b determines the K color value (% value of K) of the determination target character (step S13), and the K color value falls within the range of 76 to 100 (%) (FIG. In the case of K: 76-100), the character modification adding unit 3a refers to the character modification table 5a and changes the density of the determination target character after monochrome conversion to 40% (steps S14 and S18). In step S13, when the color value of K falls within the range of 51 to 75 (%) (in the figure, K: 51-75), the character modification adding unit 3a refers to the character modification table 5a, The density of the determination target character after monochrome conversion is changed to 60% (steps S15 and S18).

  In step S13, when the color value of K falls within the range of 26 to 50 (%) (in the figure, K: 26-50), the character modification adding unit 3a refers to the character modification table 5a, The density of the determination target character after monochrome conversion is changed to 80% (steps S16 and S18). In step S13, when the color value of K falls within the range of 0 to 25% (in the case of K: 0-25 in the figure), the character modification adding unit 3a refers to the character modification table 5a, The density of the determination target character after monochrome conversion is changed to 100% (steps S17 and S18).

  Next, the character color determination unit 4b determines whether or not all characters have been determined (step S19). If all characters have not been determined (NO), the process returns to step S8 and repeats the process. If all characters are determined in step S19 (YES), the process proceeds to step S20 in FIG.

  Next, in FIG. 7, the display unit 11 performs a preview display of the image data that has been converted into monochrome and added with character modification according to the user's operation (step S <b> 20). It is determined whether or not the cancel button 9 has been pressed (step S21). If it is determined that the cancel button of the operation unit 9 has not been pressed (in the case of NO), it is determined whether or not to print out the image data based on whether or not the user has pressed the print start button (step) S22). If it is determined in step S21 that the cancel button of the operation unit 9 has been pressed (YES), the job corresponding to the image data is canceled (step S24), and the process returns to step S1.

  In step S22, when the main control unit 4 determines that the user presses the print start button and prints out the image data (in the case of YES), the main control unit 4 instructs the printing unit 12 to execute printing, and prints according to this instruction. The unit 12 prints out the image data (step S23). If it is determined in step S22 that the user does not press the print start button and the image data is not printed out (in the case of NO), the process returns to step S21 to enter a standby state.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Color value detection part, 3 ... Image processing part, 3a ... Character modification addition part, 4 ... Main control part, 4a ... Character extraction part, 4b ... Character color determination part, 5 ... Memory | storage part, 5a ... Character modification table, 6 ... Input control unit, 7 ... LAN I / F, 8 ... Scanner unit, 9 ... Operation unit, 10 ... Output control unit, 11 ... Display unit, 12 ... Printing unit, 20 ... PC, 21 ... Printer driver.

Claims (6)

An image forming apparatus for monochrome output of color image data,
Based on a color value detection unit that detects a color value of each pixel included in the color image data, a character extraction unit that extracts a character part from the color image data, and a color value of a pixel corresponding to the extracted character part A character color determination unit that determines whether or not the character color of the character part is a predetermined color; and a character part that has been determined to be a predetermined color by the character color determination unit is subjected to monochrome conversion, and the character part after the monochrome conversion And a character modification adding part for adding character modification to
An image forming apparatus for outputting monochrome image data including a character portion to which character modification is added by the character modification adding unit.   A character modification table in which the color value of the predetermined color and character modification are registered in association with each other, and the character modification adding unit performs character modification of the character portion determined to be the predetermined color by the character color determination unit; The image forming apparatus according to claim 1, wherein the image forming apparatus is identified from a modification table, and the identified character modification is added.   The color value is a CMYK value, and the character modification adding unit decreases the density of the character part after monochrome conversion as the K value of the character part determined to be a predetermined color by the character color determination unit is smaller. The image forming apparatus according to claim 1, wherein the image forming apparatus is enlarged.   The image forming apparatus according to claim 1, wherein the character modification is at least one of bold, italic, underline, encircling, shading, and enlargement.   The image forming apparatus according to claim 1, wherein the predetermined color is a color other than black. An image output method by an image forming apparatus for monochrome output of color image data,
The image forming apparatus extracts a color value detecting step for detecting a color value of each pixel included in the color image data, a character extracting step for extracting a character portion from the color image data, and the character extracting step. A character color determining step for determining whether or not the character color of the character portion is a predetermined color based on a color value of a pixel corresponding to the character portion; and a character portion determined to be a predetermined color in the character color determining step Character conversion step for adding a character modification to the character portion after the monochrome conversion, and an image output step for outputting monochrome image data including the character portion to which the character modification has been added in the character modification addition step An image output method comprising:

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