JP2008067124A - Monochromatic image adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monochromatic image adjusting device capable of obtaining a hard copy in which each area colored by different colors in an adjacent area during creating the hard copy after monochromizing color image data can be discriminated. <P>SOLUTION: Whether a difference between density m of one area and density n of the other area is smaller than 64 is checked (S19). If the difference is smaller than 64, it is checked that m is larger than n (S20). If m is larger than n, processing is performed, which adds a designated value to m so as to make the difference larger than 64 (S21). If m is not larger than n, processing is performed, which subtracts a designated value from m so as to make the difference larger than 64 (S22). The density of an area corresponding to m of print data is rewritten to a value of corrected m. This processing is executed between areas adjacent to each other about the whole areas included in the monochromatic print data (step S23). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a monochrome image adjustment for adjusting a color density difference between adjacent regions in monochrome image data having a plurality of regions separated by contour lines and in which adjacent regions are colored with different colors. Relates to the device.

  Conventionally, a technique for converting color image data into monochrome image data is known in the field of image processing technology. In this method, for example, when the color image data is RGB format color image data, the RGB information of the color image data is only information on lightness (density) indicating the brightness of the color based on a predetermined conversion formula. Through a process of color processing for conversion to a certain gray scale, a hard copy of monochrome image data corresponding to the color image data is output from the printer (see, for example, Patent Document 1).

JP 2002-262108 A

  By the way, in the above-described method, color processing for simply converting RGB information of color image data into grayscale is performed, so an image having a plurality of regions and colored with a different color for each region. The following problems often occur in hard copy of monochrome image data obtained from data.

  That is, image data having a plurality of areas such as images such as bar graphs and pie charts and graphical graphic images using an information processing device such as a personal computer (personal computer), and different for each area. When image data colored with color is created and a hard copy of monochrome image data converted from the color image data by the above method is created, the hard copy image is not colored. ) It may be difficult to distinguish each area from the hard copy only by the difference in brightness. In particular, in the adjacent areas, when the density of the color colored in each area is close, there arises a problem that it becomes impossible to distinguish.

  Accordingly, an object of the present invention is to identify each area colored in a different color, particularly in an adjacent area, when color image data is converted into monochrome image data to create a hard copy of the monochrome image data. An object of the present invention is to provide a monochrome image adjusting apparatus capable of obtaining a hard copy.

  A monochrome image adjusting apparatus according to the present invention has a determining means for determining whether or not input monochrome image data is graphic image data having a plurality of regions divided by contour lines and regions adjacent to each other are colored in different colors. When the determination unit determines the monochrome image data as the graphic image data, when the monochrome image data is printed in monochrome, the different colors should be adjusted so that they can be distinguished only by the density difference between the colors. And determining means for determining whether or not the monochrome image data should be adjusted so that the different colors can be distinguished only by the density difference between the colors. Detecting means for detecting each of the areas and detecting the color density of each detected area; and for each area detected by the detecting means A comparison means for calculating a density difference between adjacent regions colored with different colors based on the density of the image and comparing the density difference with a predetermined density difference threshold value, and a result of comparison by the comparison means Correction means for correcting the density of any one of the adjacent regions so that the density difference exceeds the density difference threshold when the density difference is smaller than the density difference threshold. .

  In a preferred embodiment according to the present invention, the density difference threshold is variably adjusted by the user.

  In an embodiment different from the above, the correction of the density of any one of the adjacent areas by the correction unit is changed to the density of any one of the adjacent areas having a predetermined value. Or subtraction from the density of any one of the adjacent regions.

  In another embodiment different from the above, the predetermined value is set by the user.

  Further, in an embodiment different from the above, the determination by the determination means should be adjusted so that the different colors can be distinguished only by the density difference between the colors when the monochrome image data is printed in monochrome. This is done depending on whether the command is given from outside.

  According to the present invention, when color image data is converted into monochrome image data and a hard copy of the monochrome image data is created, hardware that can identify each region colored with a different color, particularly in adjacent regions. It is possible to provide a monochrome image adjusting apparatus capable of obtaining a copy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the following description, for example, a host device such as a personal computer (personal computer) and a laser printer such as a color printer or a monochrome printer connected to the host device via a communication network are assumed as the monochrome image adjusting device. However, since the device configuration itself of the personal computer and the printer does not have the technical features of the present invention, a block diagram describing the device configuration of the personal computer and the printer and a detailed description thereof will be omitted.

  FIG. 1 is an explanatory diagram showing a screen of a printer driver built in a personal computer (personal computer) constituting a monochrome image adjusting apparatus according to an embodiment of the present invention.

  The screen shown in FIG. 1 is displayed on the display unit of the personal computer when the printer driver is activated via the keyboard or the like of the personal computer. As shown in the figure, the printer driver screen selects / sets the paper size (used for printing), printing direction, paper feeding device, paper type, color, layout, duplex printing, number of copies, and the like. Including the region. A check box 1 for selecting whether or not to enable graph printing (on / off) by selecting monochrome printing in the color selection region for selecting color printing or monochrome printing is provided above. Displayed on the screen.

  In addition to the above check box 1, the user sets a numerical value for determining how much the density difference between adjacent regions, which are colored with different colors, is highlighted in graph printing. Also displayed is a stereo bar 3 to be used. The numerical values set by the stereo bar 3 will be described in detail in the flowchart shown in FIG. When the user inserts a check symbol into the check box 1 displayed on the screen, graph printing is enabled. Numerical value setting by the stereo bar 3 becomes possible when the graph printing is enabled.

  Note that the conversion from color image data to (monochrome) grayscale image data (Gray conversion (R′G′B ′ → Gray (monochrome))) performed in the printer driver is performed as follows.

            Y = 0.299 × R ′ + 0.587G ′ + 0.114B ′

  Further, γ correction (RGB → R′G′B ′) executed in the printer driver is performed as follows.

R ': 4.5 x RR <0.018
1.099 × (R ^0.45 ) −0.099 R ≧ 0.018
G ': 4.5 × GG <0.018
1.099 × (G ^0.45 ) −0.099 G ≧ 0.018
B ': 4.5 × BB <0.018
1.099 × (B ^0.45 ) −0.099 B ≧ 0.018

  The RGB → CMYK conversion executed in the printer driver is performed as follows.

C = (1−R−K) / (1−K)
M = (1−G−K) / (1−K)
Y = (1−B−K) / (1−K)
K = min (1-R, 1-G, 1-B)

  Further, CMYK → RGB conversion executed in the printer driver is performed as follows.

R = 1-min (1, C x (1-K) + K)
G = 1−min (1, M × (1−K) + K)
B = 1−min (1, Y × (1−K) + K)

  FIG. 2 is an explanatory diagram showing an example of a hard copy of a monochrome image obtained using original color image data. In the example shown in FIG. 2, a plurality of rectangular regions, each colored with a different color, are rearranged in order of taking close values when monochrome printing is performed. Accordingly, as is apparent with reference to FIG. 2, since the difference in density between adjacent rectangular areas is small, it is difficult to distinguish each rectangular area.

  In FIG. 2, the region located at the left end of the band-like image located at the uppermost stage is 0 because all of R, G, and B are colored black. The area to the right is colored blue because R and G are both 0 and B is 255. In addition, since the R and G are both 0 and B is 128, the right adjacent region is colored with a slightly dark blue color. Furthermore, the area located at the right end, which is adjacent to the right side, is 0 for both R and G and B for 85, so it is colored in a darker blue color.

  Next, the area located at the left end of the band-like image located in the second row from the top is colored red because R is 255 and G and B are both 0. The area on the right is G, which is 128 and R and B are 0, so it is colored a little dark green. Also, the region on the right side is 128 for both G and B, and R is 0, so it is colored greenish blue. Furthermore, since the region located at the right end, which is adjacent to the right, is 85 for all of R, G, and B, it is colored in gray.

  In this embodiment, in order to distinguish between adjacent regions, the color of either region is determined so that a density difference is created between the two regions by looking at the relationship between the colors colored in each of the adjacent regions. R, G, and B values are modified. In the present embodiment, the verification is performed using the band-shaped image data located in the second stage from the top.

  Note that the details of the image data in the third and lower stages from the top are omitted, but in the strip-shaped image data located at the bottom, the area located at the left end is colored green, The adjacent area is colored yellow. Furthermore, the area located at the right end is white (background color).

  FIG. 3 is a flowchart showing a color conversion method for monochrome print data in the monochrome image adjustment apparatus according to the embodiment of the present invention.

  In FIG. 3, first, the printer receives monochrome print data transmitted in a file format from the host device through the communication network. The monochrome print data is a conventional color process in which color image data is simply converted into monochrome image data (monochrome simple density data, and color differences are not clearly expressed as density differences). It is image data that has only been performed. The monochrome print data includes header information and image data. The header information includes information indicating graph printing on / off (whether or not to perform graph printing) and a density difference in graph printing. Information on the degree of adjustment is included (step S11).

  Next, the printer checks whether the graph printing is turned on by checking the header information (step S12). If the graph printing is not turned on as a result of this check (NO in step S12), the printing process may be executed as it is based on the monochrome print data. Therefore, CMYK (cyan, magenta, yellow, black) conversion processing, that is, which of the cyan, magenta, yellow, and black inks is used to print a monochrome image, in other words, each color ( A halftoning process for determining whether or not to hit the ink dots of CMYK) is performed (step S13). Then, the print head is driven to print the monochrome print data (step S14).

  On the other hand, as a result of checking whether or not the graph printing is turned on, if the graph printing is turned on (YES in step S12), the flowchart shows up to the end of file (the last file of the print data in the file format). It is checked whether a series of processing relating to the color tone conversion method has been performed (step S15). As a result of this check, if the series of processing related to the color tone conversion method shown in this flowchart is performed up to the end of file, the difference in density between the edge area of the monochrome print data and the area that does not stand out. Since there is no need to perform the processing to be performed (YES in step S15), the process proceeds to the processing operation shown in step S13 described above. On the other hand, as a result of the check, if the above-described series of processing is not performed up to the end of file (NO in step S15), the black lines of the contour lines constituting the contours of the respective areas are detected and the detected contour lines are sandwiched. Then, the density of the density clusters located on both sides (that is, the area whose outline is outlined by the black line) is detected.

  Then, the detected density of one region sandwiching the black line is set to n (any value divided from 0 to 256 levels) (step S16). Next, the detected density of the other region sandwiching the black line is set to m (any value except for the value of n, which is divided into 0 to 256 levels) (step S17), and m is It is checked whether the data is 255 indicating the background color (paper color: normally white: the brightest color) or end-of-file (no adjacent area) data. Here, m and n are variables indicating the density of the colored color in each region (step S18).

  If m is either the background color or the end-of-file as a result of this check (YES in step S18), the process proceeds to the above-described step S15. If m is neither the background color nor the end-of-file as a result of the check (NO in step S18), the density m (absolute value) of the other area and the density n (absolute value of the one area) ) (Absolute value of the density difference) is smaller than a predetermined value, that is, 64, which is a threshold value (boundary value) indicating whether or not both of the above-described regions sandwiching the black line can be distinguished. . The value 64 is 1/4 (25%) of a density value from 0 to 256 levels. If the difference value between m and n is smaller than 64, it is difficult to distinguish the above two areas. This indicates a density difference. If the difference value between m and n is larger than 64, it indicates that the density difference can be distinguished between the two areas (step S19).

  If the difference between m and n is smaller than 64 as a result of the check (YES in step S19), then it is checked whether m> n (step S20). As a result of this check, if m> n (YES in step S20), a process of adding a designated value to m is performed so that the difference value between m and n is larger than 64 (step S21). . As a result of the check, if m> n is not satisfied (NO in step S20), the same designated value as above is subtracted from m so that the difference value between n and m is larger than 64 ( Step S22). In step S21 and step S22, the reason why the designated value is added to m or the designated value is subtracted from m is that m is the object of density adjustment. Here, the designated value is a value indicating the degree of density difference between adjacent areas, and a stereo bar on the screen of the printer driver displayed on a display unit such as a personal computer by the user (in FIG. 1). It is an arbitrary value determined by operating (shown).

  When the processing operation shown in step S21 or the processing operation shown in step S22 is completed, the density of the area corresponding to m of the print data is rewritten to the value of m corrected by the processing operation described above. This process is executed between adjacent areas for all areas included in the monochrome print data. That is, the colors of all adjacent areas are compared, and if the density difference between the two is smaller than a certain value, a process for increasing the density difference is applied to all areas included in the monochrome print data. (Step S23). Next, for the next area adjacent to the area having the density value of m (m after the above correction), the same processing as that in the area is performed. After setting the density value of the next area adjacent to the area to m (step S24), the process proceeds to the processing operation shown in step S17 described above.

  On the other hand, as a result of checking whether or not the difference value between m and n is smaller than 64, if the difference value is larger than 64 (NO in step S19), the values of m and n are step S20 to step S20. Since it is not necessary to perform the correction processing shown in S23, the processing operation shown in step S24 is immediately performed to execute the processing operation in step S17 and subsequent steps on the adjacent region having the density value of m. Then, the process proceeds to the processing operation shown in step S17.

  In the above-described flowchart, the threshold value (boundary value) indicating whether or not the above two regions across the black line can be distinguished is described as 64. However, the threshold value is not necessarily limited to 64. Alternatively, another value may be set, or it may be set by the user in the same manner as the designation set by the user by operating the stereo bar 3 described above.

  As described above, according to an embodiment of the present invention, when color image data is converted to monochrome image data and a hard copy of the monochrome image data is created, coloring is performed in different colors, particularly in adjacent regions. It is possible to obtain a hard copy in which each of the recorded areas can be identified.

  The preferred embodiment of the present invention has been described above, but this is an example for explaining the present invention, and the scope of the present invention is not limited to this embodiment. The present invention can be implemented in various other forms. In the present embodiment, monochrome printing data output from a personal computer is received, and data processing is performed to make the density difference between adjacent regions stand out so that the printer can distinguish between adjacent regions. Although described as an example, the present invention can be applied to an image processing apparatus other than a printer. That is, in the image processing apparatus, monochrome print data after the density difference between adjacent areas is made to stand out through the above data processing is accumulated and used later for processing other than printing and printing. Also good.

  In addition, when each region described above is accompanied by an explanation indicating what data is written by characters or the like, when correction that makes the above-described density difference conspicuous between adjacent regions is performed, There is no problem because the density of characters and the like is also corrected. However, instead of the description using the characters and the like, if the above description is made with a legend, the color of the legend and the color of the region will be shifted if correction that makes the density difference stand out. . Therefore, when a correction that makes the density difference stand out in the area is performed, the color of the legend may be changed in synchronization therewith.

  In addition, the monochrome print data may be masked to give a pattern so that adjacent regions colored in different colors can be distinguished not only by the density difference but also by the difference in the pattern.

  Furthermore, even if different patterns are given to adjacent areas in the monochrome print data, the difference between the areas can be made more conspicuous.

FIG. 3 is an explanatory diagram showing a screen of a printer driver built in a personal computer that constitutes a monochrome image adjustment apparatus according to an embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating an example of a hard copy of a monochrome image obtained using original color image data. 6 is a flowchart showing a monochrome print data color tone conversion method in the monochrome image adjustment apparatus according to the embodiment of the present invention.

Explanation of symbols

1 Check box 1
3 Stereo bar

Claims (5)

Determining means for determining whether or not the input monochrome image data is graphic image data having a plurality of regions separated by outlines, and regions adjacent to each other are colored in different colors;
Should the discrimination means discriminate the monochrome image data from the graphic image data, when the monochrome image data is printed in monochrome, should the different colors be adjusted so that they can be distinguished only by the density difference between the colors? Judgment means for judging whether or not
When the determination means determines that the monochrome image data should be adjusted so that the different colors can be distinguished only by the density difference between the colors, the areas are detected based on the contour lines. Detecting means for detecting the color density of each region detected together with,
Based on the color density of each area detected by the detection means, a density difference between adjacent areas colored with different colors is calculated, and the density difference is compared with a predetermined density difference threshold value. Comparing means to
If the density difference is smaller than the density difference threshold as a result of the comparison by the comparing means, the density of any one of the adjacent regions is corrected so that the density difference exceeds the density difference threshold. Correction means to
Monochrome image adjustment device comprising: The monochrome image adjustment apparatus according to claim 1,
A monochrome image adjusting apparatus in which the density difference threshold is variably adjusted by a user. The monochrome image adjustment apparatus according to claim 1,
The correction of the density of any one of the adjacent areas by the correcting unit is performed by adding a predetermined value to the density of any one of the adjacent areas, or between the adjacent areas. Monochrome image adjustment device that is performed by subtraction from the density of any one of the above. The monochrome image adjustment apparatus according to claim 3, wherein
A monochrome image adjusting apparatus in which the predetermined value is set by a user. The monochrome image adjustment apparatus according to claim 1,
The determination by the determination means is performed based on whether or not an instruction is given from the outside that when the monochrome image data is printed in monochrome, the different colors should be adjusted so as to be distinguishable only by the density difference between the colors. Monochrome image adjustment device.

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