JP2009027224A - Print system, unit, method, and program for processing image, and unit, method, and program for correcting color - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a print system capable of obtaining print output enabling monochrome characters to be easily determined to be colored characters even for monochrome print, and to provide an image processing unit, a color correcting unit, an image processing method, a color correcting method, an image processing program, and a color correcting program. <P>SOLUTION: The print system has: a host computer 2 outputting a print job including colored characters to a printer 3; and the printer 3 for printing, in monochrome, an image having colored characters to which a color designation line of a line type corresponding to the color of colored characters is given based on a prescribed color correspondence rule allowing the color of characters to correspond to the line type in advance. In the monochrome printed matter of the printer 3, the color designation line is given to the colored characters, thus easily determining that the characters are colored by the color designation line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printing system that performs monochrome printing, an image processing apparatus, a color correction apparatus, an image processing method, a color correction method, an image processing program, and a color correction program.

  In recent years, while color printers capable of printing color images have become widespread, there is still a demand for monochrome printing due to cost constraints, and there are many cases where monochrome printing is performed on color image data. .

When the color image data is printed in monochrome, monochrome conversion for converting the color image data into image data for monochrome printing is performed. As a typical monochrome conversion method, there is a method of converting the RGB value of each pixel constituting color image data into a gray value (see, for example, Patent Document 1). Specifically, the RGB value is converted into a gray value Gr corresponding to the luminance according to the following equation (1) which is a luminance conversion equation. By printing a grayscale image represented by a gray value, monochrome printing in which a color image is expressed by grayscale is performed. Note that the larger the gray value Gr in Equation (1), the lower the density, and the smaller the gray value, the higher the density.
Gr = 0.3R + 0.59G + 0.11B
(However, R is red, G is green, B is blue pixel value, Gr is gray value) (1)

JP 2002-252773 A

  However, in monochrome printing, there is a problem that when a character with a color designation (hereinafter referred to as “colored character”) is printed, it is difficult to accurately read the color of the colored character from the grayscale image of the printed matter. . For example, since the gray value corresponding to blue is a relatively small value, when a blue colored character is printed in monochrome, a high-density character is printed. For this reason, the density difference from the original black-printed character becomes small, and it becomes difficult for the user to understand that the black-printed character is a blue colored character. The intention of the person who creates the document to be printed on the printer is that the characters to be emphasized to the reader are often colored characters, so it is very difficult for monochrome printing to prevent the reader from knowing that the characters are colored. It is inconvenient.

  For example, since the gray value corresponding to yellow is a relatively large value, when monochrome colored characters are printed in yellow, low-density characters are printed. Further, depending on the gradation characteristics of a printer that performs monochrome printing, it may be difficult to output low density characters at a suitable density. For these reasons, there is a problem that the visibility of colored characters is lowered in monochrome printing.

  SUMMARY An advantage of some aspects of the invention is to solve at least one of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A printing system including an image processing device that generates print data based on input data representing an input image including colored characters, and a printing device that performs monochrome printing on a print medium according to the print data. The image processing apparatus provides a color designation line for assigning a color designation line of a line type corresponding to a color of the colored character to the colored character based on a color correspondence rule in which a character color and a line type are associated in advance. A printing system comprising: an adding unit; and a print data generating unit that generates the print data corresponding to an input image including a colored character to which the color designation line is added.

  According to this configuration, color-designated lines according to the color correspondence rule are given to colored characters that are printed in black and white on the print medium, so that the colored characters among the characters printed on the print medium are color-designated. It becomes possible to easily judge from the line. Further, since a color designation line is given to the colored character, it is possible to obtain a printed output in which the colored character is emphasized even in monochrome printing.

  Application Example 2 In the printing system described above, a reading device that reads a print medium printed by the printing device and generates read image data representing a read image, and the color designation line in the read image of the read image data is assigned. And a color correction device that corrects the color of the character to a color corresponding to the color designation line based on the color correspondence rule.

  According to this configuration, the color of the character to which the color designation line is added in the read image obtained by reading the monochrome printed print medium is corrected to a color corresponding to the line type of the color designation line based on the color correspondence rule. Thus, the color of the colored character can be restored.

  Application Example 3 An image processing apparatus for generating print data for monochrome printing based on input data representing an input image including a colored character, wherein the color correspondence rule associates a character color and a line type in advance And a color designation line providing means for assigning a color designation line of a line type corresponding to the color of the colored character to the colored character, and an input image including the colored character to which the color designation line is assigned. An image processing apparatus comprising: print data generation means for generating the print data.

  According to this configuration, it is possible to obtain print data in which a colored character is assigned a color designation line of a line type according to the color correspondence rule. According to this print data, it is possible to perform monochrome printing in which a colored character can be easily determined by a color designation line.

  Application Example 4 In the image processing apparatus, the image processing apparatus further includes character color conversion means for converting a color of the colored character into a color having a maximum density in monochrome printing.

  According to this configuration, since the colored character is printed in monochrome as the character with the highest density, it is possible to prevent the visibility of the colored character from being lowered due to the decrease in the density of the colored character in monochrome printing.

  Application Example 5 In the above image processing apparatus, the color designation line provision unit imparts the color designation line so as to surround the colored character.

  According to this configuration, the colored character printed in monochrome is surrounded by the color designation line, so that the range of the colored character is indicated by the color designation line.

  Application Example 6 In the image processing apparatus, the color correspondence rule is defined for a plurality of colors, and the color designation line associated with each of the plurality of colors is in accordance with the order of hues in the plurality of colors. An image processing apparatus characterized by being a broken line in which a ratio between the length of the solid line portion and the length of the non-solid line portion is determined.

  According to this configuration, since the ratio of the length of the solid line portion to the length of the non-solid line portion in the broken line is determined according to the order of the hue, the ratio of the length of the solid line portion and the length of the non-solid line portion is close to each other Between the two broken lines, the hue difference between the colors corresponding to the broken lines is small. For this reason, even if an error occurs in the reading of the ratio between the lengths of the solid line portion and the non-solid line portion of the broken line, the hue difference from the color that should be originally judged becomes small, and the color is judged to be close to the color that should be judged Will be able to.

  Application Example 7 An image representing a monochrome image including a character to which a color designation line based on a color correspondence rule in which a character color and a line type are associated in advance is provided, for correcting a character color A character color for correcting the color of the character assigned the color designation line in the monochrome image to a color corresponding to the line type of the color designation line based on the color correspondence rule; And a correction unit.

  According to this configuration, the color of the character to which the color designation line is added in the monochrome image is corrected to a color corresponding to the line type of the color designation line based on the color correspondence rule, so that the character included in the monochrome image is corrected. Can be colored. For example, the color correction device can restore the color of the colored character by processing the monochrome printed image according to the print data generated by the image processing device.

  Application Example 8 In the color correction apparatus, the color correction apparatus further includes a removing unit that removes the color designation line from the image represented by the input image data.

  According to this configuration, since the color designation line is removed from the monochrome image including the character to which the color designation line is given, the image before the color designation line is given can be restored more faithfully.

  Application Example 9 In the color correction apparatus, a reading unit that reads a print medium on which an image including a character with a line is printed, and inputs data of the read image to the image data input unit; and the character A color correction apparatus, further comprising: a color printing unit that performs color printing on an image color-corrected by the color correction unit.

  According to this configuration, a character provided with a line included in an image read by the reading unit is corrected to a color corresponding to the line, and the character of the corrected color is printed in color. For example, when monochrome printing is performed according to the print data generated by the image processing apparatus, and the reading unit reads a monochrome printed print medium, a copy in which the color of the colored character is restored is realized.

  Application Example 10 An image processing method for generating print data for monochrome printing on the basis of input data representing an input image including colored characters, wherein the color correspondence rule associates character colors and line types in advance A color designation line of a line type corresponding to the color of the colored character is assigned to the colored character, and the print data corresponding to the input image including the colored character to which the color designation line is assigned. An image processing method comprising the steps of:

  According to this image processing method, it is possible to generate print data in which color designation lines are added to colored characters. Even if the printed matter printed in monochrome according to the print data is a monochrome printed matter, it is possible to easily determine that it is a colored character.

  Application Example 11 An image representing a monochrome image including a character to which a color designation line based on a color correspondence rule in which a character color and a line type are associated in advance is provided, which is a color correction method for correcting the color of the character. Performing a process for correcting the color of the character to which the color designation line is assigned in the monochrome image to the color corresponding to the line type of the color designation line based on the color correspondence rule. A color correction method characterized by the above.

  According to this color correction method, it is possible to restore the color of a character provided with a color designation line in a monochrome image.

  Application Example 12 An image processing program for generating print data for monochrome printing based on input data representing an input image including a colored character, the computer associating a character color with a line type Accessing a storage unit that stores correspondence rule information in advance, and based on the color correspondence rule information, a color designation line providing unit that gives a color designation line of a line type corresponding to the color of the colored character to the colored character; An image processing program that functions as a print data generation unit that generates the print data corresponding to an input image including a colored character with a color designation line.

  According to this image processing program, it is possible to generate print data in which color designation lines are added to colored characters. Even if the printed matter printed in monochrome according to the print data is a monochrome printed matter, it is possible to easily determine that it is a colored character.

  Application Example 13 A color correction program for correcting the color of a character, the computer including a character provided with a color designation line based on a color correspondence rule in which a character color and a line type are associated in advance The color of the character assigned with the color designation line is accessed based on the color correspondence rule information by accessing a storage unit that stores color correspondence rule information indicating the color correspondence rule in advance for image data representing a monochrome image. A color correction program that functions as a character color correction unit that performs processing for correcting a color corresponding to a line type of the color designation line.

  According to this color correction program, it is possible to restore the color of a character provided with a color designation line in a monochrome image.

(First embodiment)
Hereinafter, a first example according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a printing system according to the first embodiment. As shown in FIG. 1, the printing system 1 includes a host computer 2, a printer 3, and a copying apparatus (color correction apparatus) 4. In this embodiment, the printer 3 is a monochrome printer that performs electrophotographic image formation using black monochromatic toner. One copying apparatus 4 is capable of color copying, and will be used for further copying the paper S printed in black and white by the printer 3 as will be described in detail later. Hereinafter, each configuration of the printing system 1 will be described.

  First, the host computer 2 will be described. The host computer 2 is a general-purpose personal computer or the like, and is connected to the printer 3 so that data communication is possible. The host computer 2 includes a printer driver 20 that generates a print job (input data) in which an image to be printed including objects such as text, images, and graphics is described in PDL (Page Description Language). The printer driver 20 controls printing by outputting a print job to the printer 3.

  Next, the printer 3 will be described. FIG. 2 is a block diagram showing the configuration of the printer. As shown in FIG. 2, the printer 3 includes a print controller (image processing apparatus) 30 that controls the printer 3 and a print engine (printing apparatus) 31 that performs printing under the control of the print controller 30. . The print engine 31 is an engine that performs electrophotographic image formation, and includes a photosensitive drum, an exposure device that exposes the surface of the photosensitive drum, a toner cartridge that contains black toner, a developing device that develops an exposure image with toner, The image forming apparatus includes a transfer roller that transfers a toner image onto a sheet and a fixing device that fixes the toner image on a sheet (not shown).

  The print controller 30 includes a CPU 300, a ROM 301, a RAM 302, an input interface (hereinafter referred to as “input I / F”) 303 connected to the host computer 2, a color conversion unit 304, a drawing processing unit 305, a half A tone processing unit 306 and an engine interface (hereinafter referred to as “engine I / F”) 307 are included. Each of these components is connected to a bus and can exchange data with each other.

  In the ROM 301, an image processing program for performing image processing in monochrome printing and a color correspondence rule table (color correspondence rule information) described later are recorded in advance. The RAM 302 is a general-purpose memory used as a working memory or a development buffer used in drawing processing. The CPU 300 is a main control device of the printer 3 and performs various processes for controlling printing according to a print job.

  The color conversion unit 304 is a part that performs monochrome conversion by gray conversion shown in Expression (1) for an object described in a print job. The drawing processing unit 305 is a part that performs a drawing process for developing a print image in a development buffer by drawing a monochrome-converted object. The halftone processing unit 306 is a part that performs halftone processing on the developed print image and converts it into halftone dot data (print data) corresponding to dots formed by the print engine 31. The configurations of the color conversion unit 304, the drawing processing unit 305, and the halftone processing unit 306 correspond to the print data generation unit described in the claims.

  The engine I / F 307 is a part that controls the printing operation by the print engine 31 according to the halftone data after the halftone process. Specifically, the engine I / F 307 performs pulse width modulation on the data after halftone processing to convert it into an image signal that can be processed by the print engine 31, and sends the converted image signal to the print engine 31. Supply. The print engine 31 performs printing by executing image formation by exposure, development, transfer, and fixing in accordance with the supplied image signal.

  Here, in the monochrome conversion according to the equation (1), there may be a case where the color difference cannot be suitably expressed in monochrome printing. For example, since the gray value corresponding to blue is small, the difference in density is small between the print result of the object designated as blue and the print result of the black object whose gray value is “0”. Become. For this reason, it becomes difficult for the user to determine that the color of the object is designated from the monochrome printed material. That is, the monochrome print result of the object designated as blue may be misread as a black object without color designation. Furthermore, there is a concern that, due to the influence of the gradation output characteristics of the printer, the difference in color is not appropriately output as the difference in density, and the determination becomes more difficult. As described above, in the printed matter printed in monochrome, it may be difficult to convey to the user that the object is a color designated object. In particular, for text, the intention of the person who creates the document to be printed by the printer is that the character to be emphasized to the reader is a colored character, so that the color character is not communicated to the reader by monochrome printing. It was very inconvenient.

  Therefore, the printer 3 of this embodiment includes a color designation line provision unit (color designation line provision unit) 110 and a character color conversion unit (character color conversion unit) 120. These configurations function when the CPU 300 of the print controller 30 reads and executes the image processing program recorded in the ROM 301. Hereinafter, processing performed by each of these components will be described.

  The color designation line assigning unit 110 assigns a line of a line type corresponding to a color (hereinafter referred to as “color designation line”) to a colored character according to a predetermined rule (hereinafter referred to as “color correspondence rule”). I do. Colored characters here are texts designated in a color other than black in a print job. The color correspondence rule is an agreement in which the character color and the line type of the color designation line are associated with each other one by one, and data indicating the association is recorded in advance in the ROM 301 as a color correspondence rule table. Specifically, the color designation line assignment unit 110 assigns a color designation line to the print image developed in the development buffer by causing the drawing processing unit 305 to further draw the color designation line. The color designation line is used to visually determine that even a monochrome printed matter is a colored character.

  Here, the color correspondence rule will be described. FIG. 3 shows an example of a color correspondence rule table showing color correspondence rules. In the example of FIG. 3, the color designation lines corresponding to the character colors are all broken lines. For convenience of explanation, the ratio of the length of the solid line portion to the length of the non-solid line portion in the broken line is shown in parentheses in FIG. For example, according to the color correspondence rule table TL, the color designation line corresponding to the character color “green” has a ratio of the length of the solid line part to the non-solid line part “1: 2”, and the solid line part and the solid line This is a broken line in which non-solid line portions having a length twice that of the portion are alternately arranged. Similarly, the ratio of the length of the solid line portion to the length of the non-solid line portion is “2: 1” and “1: 1” in order for the character colors “blue”, “cyan”, “magenta”, and “yellow”. , “5: 1” and “1: 5”. The character color “red” is associated with a broken line whose length ratio between the solid line portion and the non-solid line portion is “1: 0”, that is, a solid line.

  In the color correspondence rule, the ratio between the solid line length and the non-solid line length in each broken line is determined according to the hue order of the corresponding color. When the colors defined in the color correspondence rule in FIG. 3 are arranged in the order of hue angles in a color space such as the LCH color system, yellow, green, cyan, blue, magenta, and red are obtained. Among these, in yellow, the ratio of the length of the solid line part to the non-solid line part is “1: 5”, and the ratio of the solid line part is the smallest. Next, in green, the ratio of the lengths of the solid line portion and the non-solid line portion is “1: 2”, and the ratio of the solid line portion is the second smallest after yellow. Similarly, the ratio of the solid line portion sequentially increases in the order of cyan, blue, and magenta, and the ratio of the solid line portion increases in red. As described above, the color of the character and the broken line are associated with each other so that the ratio of the solid line portion increases as the hue angle increases.

  The character color conversion unit 120 performs a process of color-converting the color of the character itself to black, which is the color with the maximum density in monochrome printing, so that the character has a density that allows easy reading. Specifically, when developing a colored character in the development buffer, the character color conversion unit 120 converts the color of the colored character by causing the drawing processing unit 305 to develop the black character in the development buffer.

  Thus, the colored character object described in the print job is rendered as a black character object with the color designation line by the color designation line provision unit 110 and the character color conversion unit 120. Therefore, in the printer 3, the colored characters described in the print job are printed in black and white as black characters with color designation lines.

  Next, the copying apparatus 4 will be described. The copying apparatus 4 is used when copying a sheet printed in monochrome by the printer 3. FIG. 4 is a block diagram showing the configuration of the copying apparatus. As shown in FIG. 4, the copying apparatus 4 includes a copy controller 40 that controls copying, a scan engine (reading unit) 41 that reads a document sheet, and a print engine (color printing unit) 42 that can perform color printing. .

  The copy controller 40 includes a CPU 400, a ROM 401, a RAM 402, a color conversion unit 403, a halftone processing unit 404, a scanner interface (hereinafter referred to as “scanner I / F”) 405, and a print interface (hereinafter referred to as “print”). I / F ”) 406.

  The CPU 400 is a main control device of the copying apparatus 4. In the ROM 401, a color correction program and the same color correspondence rule table TL as those recorded in the printer are recorded in advance. The RAM 402 is a general-purpose memory used as a working memory.

  The scanner I / F 405 is a part that controls the operation of the scan engine 41. The scanner I / F 405 performs processing for causing the scan engine 41 to read a sheet placed on a document table (not shown), and reads the scanned image from the scan engine 41 in RGB colors. A process of receiving read image data expressed in a bitmap format is performed.

  The color conversion unit 403 performs a process of converting the read image data into CMYK image data. The halftone processing unit 404 performs halftone processing for converting CMYK image data into data corresponding to dots formed by the print engine 42. The print I / F 406 is a part that controls the operation of the print engine 42. Specifically, the print I / F 406 performs pulse width modulation on the image data of each color of CMYK after halftone processing, generates an image signal that can be processed by the print engine 42, and outputs this image signal to the print engine 42. By supplying, the print engine 42 performs a color printing process.

  As described above, the copying apparatus 4 can perform color copying of a document by reading the paper placed on the document table and performing color printing on the read image.

  Here, in the case of a normal copying apparatus, when the color printed on the paper printed in monochrome by the printer 3, since the original itself is monochrome, the copied material is also monochrome. On the other hand, the copying apparatus 4 restores the color of the colored characters once printed by the printer 3 in order to restore the color of the character with the color designation line included in the read image (character color correction unit). A correction unit) 210 and a color designation line removal unit (removal unit) 220 that removes the assigned color designation line from the read image. That is, according to the copying apparatus 4, the color of the black character to which the color designation line is given is corrected to a color corresponding to the line type of the color designation line given according to the color correspondence rule, and the color designation line is corrected. By removing the, the color character is restored. Each configuration of the character color correction unit 210 and the color designation line removal unit 220 functions when the CPU 400 of the copy controller 40 reads out and executes a color correction program recorded in the ROM 401.

  Next, the flow of processing performed in the printing system 1 described above will be described in detail according to a flowchart.

  First, monochrome printing by the printer 3 will be described with reference to the flowchart of FIG. When the printer 3 receives a print job from the printer driver 20, the CPU 300 starts the processing in FIG. When the process is started, the CPU 300 interprets the received print job code (step S100), and determines whether or not the object of the interpreted code is a colored character (step S110).

  If it is a colored character (step S110: Yes), the CPU 300 refers to the color correspondence rule table TL recorded in the ROM 301, and selects a color designation line of a line type corresponding to the color of the colored character, that is, a broken line ( Step S120).

  Next, the CPU 300 instructs the drawing processing unit 305 to draw the frame so that the frame surrounding the colored character by the selected broken line is written in the expansion buffer (step S130). Next, the CPU 300 converts the color of the colored character to black (step S140), and instructs the drawing processing unit 305 to write the color-converted black character in the expansion buffer, thereby drawing the black character. (Step S150). If black characters are drawn, the process proceeds to step S180.

  On the other hand, if it is determined in step S110 that the character is not a colored character (step S110: No), the CPU 300 converts the color of the object to be processed into monochrome by gray conversion according to equation (1) (step S160). Then, the CPU 300 writes the image data of the monochrome converted object in the expansion buffer, and draws the monochrome converted object (step S170). If the monochrome-converted object is drawn, the process proceeds to step S180.

  When the process proceeds from step S150 or S170 to step S180, the CPU 300 determines whether drawing has been completed for all the objects described in the print job. If drawing has not been completed for all objects (step S180: No), the code for the next object is interpreted (step S185), and the process returns to step S110 to perform processing for the next object. In this manner, the processing is repeatedly performed for each object described in the print job, and when drawing is completed for all objects (step S180: Yes), the CPU 300 instructs the halftone processing unit 306 to execute the development buffer. The halftone process is performed on the image developed in step S190. Then, the engine I / F 307 is instructed to apply pulse width modulation to the image after the halftone processing, and output the modulated image signal to the print engine 31 (step S195). As a result, a color designation line is given to the colored character, and an image in which the color of the colored character is converted to black is printed in monochrome by the print engine 31.

  Steps S120 and S130 correspond to processing performed by the CPU 300 as the color designation line adding unit 110, and steps S140 and S150 correspond to processing performed by the CPU 300 as the character color conversion unit 120.

  Here, an example of monochrome printing by the printer 3 will be described. FIG. 6A is a diagram illustrating an example of paper on which color printing is performed by a normal printer, and FIG. 6B is a diagram illustrating an example of paper on which monochrome printing is performed by the printer 3. When color printing is performed by a normal printer, as shown in FIG. 6A, on the paper S, the object OB1 which is a colored character whose designated color is red is red, and the object OB2 which is a colored character whose designated color is blue is The object OB3, which is blue and has a designated color of black, is printed in black. On the other hand, when monochrome printing is performed by the printer 3, as shown in FIG. 6B, the black character object OB3 is printed in the same color, while the colored character objects OB1 and OB2 each have a color. A line type frame that complies with the corresponding rules is given. That is, the object OB1 is surrounded by a frame f1 of a color designation line (solid line) corresponding to red. Since the object OB1 is an underlined character, a frame f1 is provided so as to surround the colored character and the underline. The object OB2 is surrounded by a frame f2 of a color designation line corresponding to blue (a broken line with a ratio of a solid line portion to a non-solid line portion of “2: 1”). Thus, according to the printer 3, it is possible to obtain a printed matter in which a frame of a color designation line is drawn around colored characters.

  Further, as shown in FIG. 6B, the color of the character itself of the object OB1 whose designated color is red and the object OB2 whose designated color is blue is printed in black which is the maximum density in monochrome printing.

  Next, the flow of processing when the copying apparatus 4 copies the sheet S printed by the printer 3 in monochrome will be described. For example, the user sets the paper S after monochrome printing shown in FIG. 6 on the document table of the copying apparatus 4, and operates the operation panel (not shown) of the copying apparatus 4 with the paper set. When a copy instruction is input, processing according to the flowchart of FIG. 7 is started.

  When the process is started, the CPU 400 causes the scan engine 41 to read the paper set on the document table via the scanner I / F 405 (step S200). At this time, the scanner I / F 405 generates a read image from the image signal read by the scan engine 41.

  Next, CPU 400 determines whether or not there is a framed character in the read image (step S210). Here, the processing is performed by searching for characters included in the read image and determining whether or not a frame is provided around the searched characters.

  If there is a character with a frame (step S210: Yes), the CPU 400 refers to the color correspondence rule table TL recorded in the ROM 401, selects a color corresponding to the line type of the frame, The color is determined as the selected color (step S220). Then, the frame is removed from the character with the frame (step S230), and the color of the character itself within the frame in the read image is corrected to the color determined in step S220 (step S240). Next, the CPU 400 outputs the read image data from which the color of the framed character is corrected and the frame of the color designation line is deleted via the print I / F 406, thereby correcting the print engine 42. The read image is printed (step S250).

  On the other hand, if it is determined in step S210 that there is no framed character (step S210: No), the CPU 400 prints the read image data without performing the processing of S220 to S240 on the read image. By outputting via the I / F 406, the print engine 42 is caused to print the read image (step S250).

  When the read image is printed in step S250, the sheet S set on the document table is copied, and the process of FIG.

  For example, when a sheet printed in black and white by the printer 3 (see FIG. 6B) is copied by the copying apparatus 4, the character colors of the objects OB1 and OB2, to which color designation lines are given, are color designated according to the color designation rules. By correcting the color corresponding to the line and deleting the frame of the color designation line, the printed material on which the normal color printing illustrated in FIG. 6A is performed from the printed material of the printer 3 illustrated in FIG. A copy equivalent to is output.

  According to the first embodiment described above, the following effects can be obtained.

  (1) As shown in FIG. 6B, since the color designation line is given to the colored characters on the paper S printed by the printer 3 in monochrome, even if the printed matter is printed in monochrome, From the color designation line, it can be easily known that the character is a monochrome-printed colored character. Even in monochrome printing, it is possible to obtain a printed output in which colored characters are emphasized by color designation lines.

  (2) Since the type of the broken line of the color designation line is determined according to a predetermined color correspondence rule, if the user knows the color correspondence rule, the color designated for the character from the printed matter printed in monochrome can be obtained. I can know.

  (3) Since the character itself of the colored character to which the broken line frame is added is printed in black and white as the black character corresponding to the color with the maximum density in monochrome printing, the density of the colored character is reduced during monochrome printing. It can prevent that visibility and readability fall.

  (4) Since the copying apparatus 4 corrects the color of the character to which the frame of the color designation line is attached based on the color correspondence rule, the color of the colored character before the monochrome printing from the monochrome printed matter of the printer 3, that is, the print job It is possible to obtain a copy in which the color specified in (1) is restored.

  (5) Since the copying apparatus 4 deletes the frame of the color designation line assigned in the monochrome printing of the printer 3 in the copying, the copying is faithful to the image before the monochrome printing, that is, the image described in the print job. You can get things. That is, even when monochrome printing is performed by the printer 3, it is possible to obtain a copy equivalent to a printed material when printed by a normal color printer instead of the printer 3.

(Second embodiment)
Next, a second embodiment will be described. In the second embodiment, a process of giving a color designation line to a colored character and a process of converting the character color to black are performed by a driver of the host computer. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted.

  FIG. 8 is a diagram illustrating a configuration of a printing system according to the second embodiment. As shown in FIG. 8, the printing system 5 includes a host computer 6, a printer 7 that performs monochrome printing, and a scanner 8 that reads a sheet S printed in monochrome.

  The host computer 6 includes a CPU 600, a ROM 601, a RAM 602, a hard disk (hereinafter referred to as “HD”) 603, and an input / output interface (hereinafter referred to as “input / output I / F”) 604. The input / output I / F 604 is connected to the printer 7 and the scanner 8, and the host computer 6 can perform data communication with the printer 7 and the scanner 8.

  The HD 603 of the host computer 6 stores a printer driver driver program, a scanner driver driver program, and a color correspondence rule table TL. When the CPU 600 reads out and executes the driver program of the printer driver from the HD 603, the printer driver 100 including the color designation line adding unit 110 and the character color conversion unit 120 functions. In addition, the CPU 600 reads out and executes the driver program of the scanner driver from the HD 603, so that the scanner driver 200 having the character color correction unit 210 and the color designation line removal unit 220 functions.

  The driver program is supplied to the host computer 6 in a form recorded on a recording medium. Examples of the recording medium include various computer-readable recording media such as a flexible disk, an optical disk such as a CD-ROM and a DVD-ROM, a magneto-optical disk, a memory card, and a portable hard disk. However, the host computer 6 may download the driver program from the server via the telecommunication line and record the program in the HD 603.

  The printer driver 100 refers to the color correspondence rule table TL recorded on the HD 603 by the color designation line adding unit 110 for a color character included in an image to be printed received from an application (not shown) or the like. In addition to assigning a designated line, the character color conversion unit 120 converts the color of the character to black, and generates a print job (print data) of an image that has been given the color designated line and has undergone color conversion. By outputting the generated print job to the printer 7, as shown in FIG. 6B as an example, an image in which a color designation line is added and the color of the colored character is corrected to black is displayed on the printer 7. Let it print.

  The scanner driver 200 controls the scanner 8 to read the paper printed by the printer 7 and receives the read image data from the scanner 8. Then, with respect to the received read image, the character color correction unit 210 refers to the color correspondence rule table TL recorded in the HD 603 to restore the color of the colored character, and the color designation line removal unit 220 creates the color designation line. Remove. In this way, image data in which the color of the colored character is restored can be obtained from the sheet S printed in monochrome.

  According to the second embodiment described above, the same effect as that of the first embodiment can be obtained.

  The first embodiment and the second embodiment have been described above, but the present printing system is not limited to this, and the following modifications may be made.

  (Modification 1) In the first and second embodiments, the line to be added to the colored character is a broken line, but the line type of the color designation line to be added is not limited to this. For example, a solid line may be given. In this case, as shown in the color correspondence rule table TL in FIG. 9A, it is desirable to associate the character color with the line width of the color designation line. Moreover, you may make it give a wavy line. In this case, as shown in the color correspondence rule table TL in FIG. 9B, it is desirable to associate the character color with the wavy line period. Furthermore, a double line or a zigzag line may be used as the color designation line. However, lines of various line types such as a broken line, a solid line, and a wavy line may be used in one color correspondence rule table TL.

  (Modification 2) In the first and second embodiments described above, an example has been described in which six colors of red, green, blue, cyan, magenta, and yellow are associated with each other by the color correspondence rule. May increase. However, the number of colors may be less than six. For example, only red that is used relatively frequently for characters to be emphasized may be associated with a color designation line. Further, a color designation line having a color closest to the hue may be added to colored characters not defined in the color correspondence rule.

  (Modification 3) In the first and second embodiments, the hue of the color and the broken line in the color correspondence rule are associated with each other, but may be associated with saturation, lightness, or chromaticity coordinates.

  (Modification 4) In the first and second embodiments, a frame-shaped color designation line is added to a colored character, but the shape of the color designation line is not limited to this. For example, a color designation line may be provided below or above the colored character, or a bracket-shaped color designation line that sandwiches the colored character may be provided.

  (Modification 5) In the first and second embodiments, the functions of the color designation line assigning unit 110, the character color conversion unit 120, the character color correction unit 210, and the color designation line removal unit 220 are implemented by software. Although the example to implement | achieve was demonstrated, you may implement | achieve said function with hardware. In the first embodiment, the example in which the rendering process, the color conversion process, and the halftone process are performed by hardware has been described. However, the rendering process may be performed by software.

  (Modification 6) In the first embodiment, the case where the printer as the printing apparatus is a monochrome printer has been described as an example. However, the present invention can also be applied to the case where monochrome printing is performed by a printer capable of color printing. In the first embodiment, an electrophotographic printer has been described as an example. However, a printer of another printing method such as an ink jet method or a thermal transfer method may be used. A printing apparatus that performs monochrome printing may be a copying machine, a digital multifunction peripheral, or a facsimile apparatus.

1 is a diagram illustrating a schematic configuration of a printing system according to a first embodiment. FIG. 2 is a block diagram illustrating a configuration of a printer. The figure which showed an example of the color correspondence rule table which shows a color correspondence rule. FIG. 2 is a block diagram showing a configuration of a copying apparatus. The flowchart which showed the flow of the process of monochrome printing. 4A and 4B are diagrams illustrating an example of monochrome printing, in which FIG. 4A illustrates an example of paper on which color printing is performed by a normal printer, and FIG. 5B illustrates an example of paper on which monochrome printing is performed by the printer. 6 is a flowchart showing a flow of copying processing. The figure which showed the structure of the printing system which concerns on a 2nd Example. It is explanatory drawing of a 1st modification, (a), (b) is a figure showing an example of a color correspondence rule table.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printing system which concerns on 1st Example, 2 ... Host computer, 3 ... Printer, 4 ... Copier as color correction apparatus, 5 ... Printing system which concerns on 2nd Example, 6 ... Image processing apparatus and color Host computer as correction device, 7: Printer as printing device, 8 ... Scanner as reading device, 20 ... Printer driver, 30 ... Print controller as image processing device, 31 ... Print engine as printing device, 40 ... Copy Controller: 41 ... Scan engine as reading unit, 42 ... Print engine as color printing unit, 100 ... Printer driver as print data generation means, 110 ... Color designation line provision unit as color designation line provision means, 120 ... Character Character color conversion unit as color conversion means, 200 ... scanner driver, 210 ... character color Character color correction unit as corrective means, 220 ... Color designation line removal part as removal means, 303 ... Input interface, 305 ... Drawing processing part, 405 ... Scanner interface as image data input part, S ... Paper, TL ... Color Color correspondence rule table as correspondence rule information.

Claims (13)

A printing system comprising: an image processing device that generates print data based on input data representing an input image including colored characters; and a printing device that performs monochrome printing on a print medium according to the print data,
The image processing apparatus includes:
Based on a color correspondence rule that associates a character color and a line type in advance, a color designation line providing unit that assigns a color designation line of a line type corresponding to the color of the colored character to the colored character;
And a print data generation unit configured to generate the print data corresponding to an input image including a colored character to which the color designation line is added. The printing system according to claim 1,
A reading device that reads a print medium printed by the printing device and generates read image data representing a read image;
A color correction device that corrects the color of the character to which the color designation line is added in the read image of the read image data to a color corresponding to the color designation line based on the color correspondence rule; Printing system to do. An image processing apparatus that generates print data for monochrome printing based on input data representing an input image including colored characters,
Based on a color correspondence rule that associates a character color and a line type in advance, a color designation line provision unit that assigns a color designation line of a line type corresponding to the color of the colored character to the colored character;
An image processing apparatus comprising: a print data generation unit configured to generate the print data corresponding to an input image including a colored character provided with the color designation line. The image processing apparatus according to claim 3.
An image processing apparatus, further comprising: a character color converting unit that converts the color of the colored character into a color having a maximum density in monochrome printing. The image processing apparatus according to claim 3 or 4,
The image processing apparatus according to claim 1, wherein the color designation line provision unit provides the color designation line so as to surround the colored character. The image processing apparatus according to claim 5.
The color correspondence rule is defined for a plurality of colors,
The color designation line associated with each of the plurality of colors is a broken line in which a ratio between the length of the solid line portion and the length of the non-solid line portion is determined according to the order of hues in the plurality of colors. An image processing apparatus. A color correction device for correcting the color of characters,
An image data input unit for inputting image data representing a monochrome image including a character provided with a color designation line based on a color correspondence rule in which a character color and a line type are associated in advance;
Character color correction means for correcting the color of the character to which the color designation line is assigned in the monochrome image to a color corresponding to the line type of the color designation line based on the color correspondence rule. Color correction device. The color correction apparatus according to claim 7,
A color correction apparatus, further comprising: a removing unit that removes the color designation line from an image represented by the input image data. The color correction apparatus according to claim 7 or 8,
A reading unit that reads a print medium on which an image including characters with lines is printed, and inputs data of the read image to the image data input unit;
A color correction apparatus, further comprising: a color printing unit that performs color printing on the image color-corrected by the character color correction unit. An image processing method for generating print data for monochrome printing based on input data representing an input image including colored characters,
Assigning a color designation line of a line type corresponding to the color of the colored character to the colored character based on a color correspondence rule in which a character color and a line type are associated in advance;
Generating the print data corresponding to an input image including a colored character to which the color designation line is assigned. A color correction method for correcting the color of characters,
For image data representing a monochrome image including a character provided with a color designation line based on a color correspondence rule in which a character color and a line type are associated in advance.
Performing a process of correcting the color of the character to which the color designation line is added in the monochrome image to a color corresponding to a line type of the color designation line based on the color correspondence rule. Correction method. An image processing program for generating print data for monochrome printing based on input data representing an input image including colored characters,
Computer
A storage unit that stores in advance color correspondence rule information in which a character color and a line type are associated is accessed, and based on the color correspondence rule information, a color designation line of a line type corresponding to the color of the colored character is A color designation line giving means for giving to the colored character;
An image processing program that functions as a print data generation unit that generates the print data corresponding to an input image including a colored character with a color designation line. A color correction program for correcting the color of characters,
Computer
For image data representing a monochrome image including a character provided with a color designation line based on a color correspondence rule in which a character color and a line type are associated in advance.
Access to a storage unit that stores in advance color correspondence rule information indicating the color correspondence rule, and based on the color correspondence rule information, the color of the character to which the color designation line is assigned corresponds to the line type of the color designation line A color correction program that functions as a character color correction unit that performs processing for correcting a color to be corrected.

Images