JP2013165423A - Image processing device, image processing method and image processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing device that not only makes a difference among colors in an original color image intelligible but also can represent a characteristic portion of a pattern even for a region having a small area, and further to provide an image processing program and an image processing method.SOLUTION: An image processing device 100 comprises: a pattern type determining section 41 by which a pattern is determined in response to color information of an image; a region setting section 42 by which a region in the image is set; a position correcting section 43 by which a positional relation between a characteristic portion capable of determining a pattern type provided to a pattern and the region is corrected; and an image data generating section 45 by which image data containing the image and the pattern are generated. An application position of the characteristic portion in the region is corrected towards a center of gravity of the region by the position correcting section 43.

Description

  The present invention relates to an image processing apparatus, an image processing method, and an image processing program that perform image processing of color image data.

  Conventionally, a color image having the same luminance cannot be distinguished from a monochrome printed image. Therefore, Patent Document 1 proposes a method of generating a pattern corresponding to the original color image data based on the three primary color components obtained by separating the color information of the color image data. According to the method described in Patent Document 1, the color difference in the original color image is reflected in the output image as a different pattern. By printing this output image, it becomes possible to grasp different colors on the color image even if the color image is printed in monochrome.

Japanese Patent Laid-Open No. 11-17916

  However, since the method described in Patent Document 1 generates a pattern for each of the three primary color components based on hue, saturation, luminance, and the like, a huge number of types of patterns are generated. For this reason, it is difficult for the user to distinguish patterns having similar feature portions that can determine the pattern type, and it is difficult to understand the color difference in the original color image. In addition, when the method described in Patent Document 1 is applied to a region having a small area, depending on the type of pattern, it may not be possible to express all of the features that can identify the type of pattern in the region. In this case, the type of pattern cannot be determined, and it is difficult to recognize the color of the original color image.

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

  Application Example 1 Determined by a pattern type determining unit that determines a predetermined pattern corresponding to color information of an image, an area setting unit that sets a predetermined area in the image, and the pattern type determining unit Image data including a position correction unit that corrects a positional relationship between the feature that can determine the type of the pattern included in the pattern and the region set by the region setting unit, and the image and the pattern are generated. An image data generation unit, wherein an application position of the feature in the region is corrected toward a center of gravity of the region by the position correction unit.

  According to this image processing apparatus, the application position of the pattern feature in the predetermined area of the original image is corrected toward the center of gravity of the area. Therefore, the user can easily distinguish the color difference by easily determining the pattern type even in a predetermined area having a small area. The original image is regenerated as image data to which a pattern corresponding to the color information of the original image is applied. Therefore, the color difference in the original image can be easily distinguished by discriminating the type of pattern represented in the regenerated image data.

  Application Example 2 In the image processing apparatus, the application position of the feature portion is corrected when the area is equal to or larger than a minimum unit capable of representing the feature portion. .

  According to this configuration, even if the area where the pattern appears is small, the user can easily distinguish the color correspondence from the pattern.

  Application Example 3 In the image processing apparatus, the pattern density or / and the density of the image are changed by the image data generation unit corresponding to the color information.

  According to this configuration, the density of the pattern of the image data and / or the density of the image is changed corresponding to the color information of the original image, so that the user can easily determine the correspondence between the colors of the original image. be able to.

  Application Example 4 In the image processing apparatus, the image processing apparatus further includes a storage unit that stores correspondence information in which the color information is associated with a number of patterns smaller than the number of the color information. apparatus.

  According to this configuration, since the pattern corresponding to the color information of the image is uniquely determined, the load of the image data generation process can be reduced. Further, since the number of pattern types can be reduced with respect to the color information of the image, it is possible to suppress the possibility that the features that can distinguish the pattern type are similar. Correspondence can be easily determined.

  Application Example 5 In the image processing apparatus, the area is an area indicating a legend.

  According to this configuration, it is possible to obtain image data that allows the user to easily grasp the color correspondence between the graph and the legend.

  Application Example 6 In the above image processing apparatus, the image data is monochrome image data.

  According to this configuration, it is possible to obtain monochrome image data in which the user can easily distinguish the color difference in the original color image.

  Application Example 7 In the image processing apparatus, a step of determining a predetermined pattern corresponding to color information of an image, a step of setting a predetermined region in the image, and the pattern included in the determined pattern Correcting the positional relationship between the feature capable of distinguishing the seed and the set region, and generating image data including the image and the pattern, and applying the feature in the region An image processing method, wherein the position is corrected toward the center of gravity of the region.

  Application Example 8 The computer includes a pattern type determining unit that determines a predetermined pattern corresponding to color information of an image, an area setting unit that sets a predetermined area in the image, and the pattern type determining unit. The feature part capable of discriminating the type of the pattern included in the pattern to be determined, the position correction part for correcting the positional relationship between the area set by the area setting part, the image and the pattern An image processing program that functions as an image data generation unit that generates image data to be included, and corrects the application position of the feature in the region toward the center of gravity of the region by the position correction unit.

  According to these image processing method and image processing program, the application position of the pattern feature in the predetermined area of the original image is corrected toward the center of gravity of the area. Therefore, the user can easily distinguish the color difference by easily determining the pattern type even in a predetermined area having a small area. The original image is regenerated as image data to which a pattern corresponding to the color information of the original image is applied. Therefore, the color difference in the original image can be easily distinguished by discriminating the type of pattern represented in the regenerated image data.

1 is a diagram illustrating a schematic configuration of a printing system according to an embodiment. FIG. 2 is a diagram illustrating a software configuration of an image processing apparatus. It is the figure which showed the example of a response | compatibility with the hue on a hue ring, and a hatch pattern. It is the figure which showed an example of the pattern selection table. It is explanatory drawing explaining the allocation method of a hatch pattern. It is the figure which showed the result of applying a hatch pattern. It is explanatory drawing explaining the characteristic part of a hatch pattern. It is the figure which showed the result of applying a hatch pattern. It is the figure which showed the result of having performed the position correction process. It is the flowchart which showed the flow of the process which an image processing apparatus performs. It is explanatory drawing explaining the allocation method of a hatch pattern. It is a conceptual diagram of a position correction process. It is the figure which showed an example of the printing result of a monochrome image. It is explanatory drawing of the modification 5.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a printing system including a computer as an example of an image processing apparatus will be described.

  FIG. 1 is a diagram illustrating a schematic configuration of a printing system 1. As shown in FIG. 1, the printing system 1 includes a computer 10 and a printing device 20, and the computer 10 and the printing device 20 are connected to each other so that data communication is possible.

  The printing apparatus 20 includes a print engine 21 that prints on a medium such as paper, and a controller 22 that controls the operation of the print engine 21. The printing apparatus 20 performs processing for receiving a print job from the computer 10, processing for causing the print engine 21 to execute printing according to the print job, and the like under the control of the controller 22.

  The computer 10 is, for example, a general-purpose personal computer in which a printing device driver is installed, and is a host device of the printing device 20 that transmits a print job to the printing device 20. The computer 10 includes a CPU 11, a ROM 12, a RAM 13, a hard disk drive 14, a reading device 15, and a communication I / F 16. Note that these components of the computer 10 are connected to the bus 17 and configured to be capable of data communication with each other via the bus 17.

  The CPU 11 is a control device that controls each component of the computer 10. The ROM 12 is a non-volatile memory in which a predetermined program for controlling the computer 10 is recorded, and the RAM 13 is a general-purpose memory used as a working memory.

  The hard disk drive 14 stores in advance a driver program DP for the printing apparatus 20, a pattern selection table PT, and pattern data PD, which will be described later. The driver program DP is supplied to the computer 10 by the recording medium M on which the driver program DP is recorded, and the hard disk drive 14 stores a program read from the recording medium M by the reading device 15. Examples of the recording medium M include portable recording media such as a flexible disk, a magneto-optical disk, a USB memory, and a memory card in addition to an optical disk such as a CD-ROM and a DVD-ROM. Furthermore, the pattern selection table PT and the pattern data PD are recorded on the recording medium M, and the pattern selection table PT and the pattern data PD are stored in the hard disk drive 14 together with the driver program DP. However, the driver program DP, the pattern selection table PT, and the pattern data PD are not limited to this and are supplied from a predetermined server via, for example, an electric communication line or an optical communication line. You may do it.

  The communication I / F 16 is an interface portion that is connected to the printing apparatus 20 via a cable or wireless communication. Communication between the printing apparatus 20 and the computer 10 is performed via the communication I / F 16.

  Further, the CPU 11 of the computer 10 reads and executes the driver program DP stored in the hard disk drive 14 to install the printing apparatus driver. As a result, the computer 10 functions as the image processing apparatus 100.

  Next, the image processing apparatus 100 will be described. FIG. 2 is a diagram illustrating a software configuration of the image processing apparatus 100. As illustrated in FIG. 2, the image processing apparatus 100 includes an application 30 and a printing apparatus driver 40.

  The application 30 is software serving as a print request source for the printing apparatus 20 such as document creation software or a web browser. The application 30 generates a print request and color image data to be printed and passes it to the printing apparatus driver 40.

  The printing device driver 40 is software for controlling printing by the printing device 20. The printing device driver 40 generates print data in a data format that can be processed by the printing device 20 from the print request and color image data received from the application 30 and transmits the print data to the printing device 20 via the communication I / F 16. To do. As a result, the printing apparatus driver 40 causes the printing apparatus 20 to execute printing.

  Further, the printing apparatus driver 40 according to the present embodiment converts color image data, which is original image data, into monochrome image data with a hatch pattern, thereby distinguishing color differences in the original color image by hatching patterns. It has a function of causing the printing apparatus 20 to print as a possible monochrome image. In order to realize the monochrome printing function with the hatch pattern, the printing apparatus driver 40 includes a pattern type determination unit 41, an area setting unit 42, a position correction unit 43, a pattern density determination unit 44, and a monochrome image data generation unit. (Image data generation unit) 45. Note that these configurations of the printing apparatus driver 40 function by the CPU 11 executing the driver program DP.

  The pattern type determination unit 41 performs a process of determining a hatch pattern to be applied to the image area of the color image data according to the color information of the color image of the color image data, particularly the hue information. In the present embodiment, a plurality of types of hatch patterns are used in which hatch patterns such as vertical lines, horizontal lines, grid lines, diagonal lines, and diagonal grid lines are represented by a single color density.

  FIG. 3 is a diagram showing an example of correspondence between hues and hatch patterns. As shown in FIG. 3, a predetermined hatch pattern is assigned to each color region obtained by dividing the hue circle of the color with respect to the hue. In the example of FIG. 3, the hue on the hue circle is divided into 12 color regions, and each color region is pre-assigned with a pattern such as a vertical line, horizontal line, diagonal line, grid line, diagonal grid line, etc. as a hatch pattern. ing. The pattern type determination unit 41 selects a hatch pattern to be applied from a plurality of types of hatch patterns according to the hue of the color image. However, in the present embodiment, a hatch pattern having a different pattern is selected from a plurality of hatch patterns according to the hue, but a hatch pattern having a different pattern may be selected according to lightness and saturation. Good.

  The area setting unit 42 performs a process of setting a target area to which the hatch pattern described above is applied in the image area of the color image.

  The position correction unit 43 performs position correction processing for moving the hatch pattern with respect to the target area. A detailed description of this position correction process will be given later.

  The pattern density determination unit 44 performs a process of determining the density of the hatch pattern according to the color of the color image of the color image data, particularly the brightness. Note that the hatch pattern of the present embodiment includes a foreground area of the hatch pattern itself and a background area that is a background for the hatch pattern that is the foreground. The pattern density determining unit 44 determines a monochrome density in the foreground area (hereinafter referred to as “foreground density”) and a monochrome density in the background area (hereinafter referred to as “background density”).

  The monochrome image data generation unit 45 has the hatch pattern determined by the pattern type determination unit 41 and the hatch pattern having the background density and the foreground density determined by the pattern density determination unit 44 in the image area of the color image. The process applied to the target area is performed. Accordingly, the monochrome image data generation unit 45 generates monochrome image data with a hatch pattern represented by the applied hatch pattern.

  The processing by the pattern type determination unit 41 and the pattern density determination unit 44 described above is performed according to the pattern selection table (corresponding information) PT and the pattern data PD. Next, the pattern selection table PT and the pattern data PD will be described in order to explain a method for converting color image data into monochrome image data with hatch patterns. In the following description, the color image data represents each color of R (red), G (green), and B (blue) with an 8-bit gradation value “0 to 255” for each pixel of the color image. It shall have RGB values. The monochrome image data has a K value representing the K (black) color with an 8-bit gradation value “0 to 255”, that is, a density of K single color, for each pixel of the monochrome image. Further, regarding the RGB values of the color image data, (R, G, B) = (255, 255, 255) corresponds to white, (R, G, B) = (0, 0, 0) corresponds to black, and K Regarding the values, K = 0 corresponds to black, and K = 255 corresponds to white. However, in the present embodiment, the color image data and monochrome image data described above will be described as an example, but the data format of the color image data and monochrome image data is not limited to this.

  FIG. 4 is a diagram showing an example of the pattern selection table PT. As shown in FIG. 4, in the pattern selection table PT, a pattern type, a foreground density, and a background density are associated in advance with RGB values that are color values.

  In the pattern type column of the pattern selection table PT, as described with reference to FIG. 3, the color value is selected from a plurality of types of hatch patterns such as vertical lines, horizontal lines, grid lines, diagonal lines, and diagonal grid lines. The hatch pattern type is specified. As the type of hatch pattern, a number smaller than the number of combinations of color values, which is also one of color information, is designated. That is, when the color information of the color image is determined, the type of hatch pattern corresponding to the color information is also uniquely determined, so that the load of the monochrome image data generation process can be reduced. In addition, since the number of types of hatch patterns can be reduced with respect to the color information of the image, the number of types of similar hatch patterns can be suppressed, and the user can display the colors and hatch patterns of the original color image. It is specified so that the correspondence with the monochrome image data with the hatch pattern can be easily determined. In the foreground density column, a foreground density value corresponding to a color value is designated. In the background density column, a background density value corresponding to the color value is designated. Note that the values of the foreground density and the background density are determined in advance so that the average brightness of the applied area is the same before and after the hatch pattern is applied. Accordingly, the density of the pattern or / and the density of the image in the monochrome image data is changed corresponding to the color information of the original image, so that the user can easily determine the correspondence between the colors of the original image. it can.

  The pattern selection table PT determines the type of hatch pattern, foreground density and background density corresponding to the RGB values of the color image. That is, when converting color image data to monochrome image data, the pattern type determination unit 41 refers to the pattern selection table PT and enters the pattern type column of the pattern selection table PT for the image area of the color image data. Select the hatch pattern with the specified hatch pattern. The pattern density determination unit 44 refers to the pattern selection table PT to determine the background density of the hatch pattern to the density specified by the background density column of the pattern selection table PT and to change the foreground density of the hatch pattern to the pattern. The foreground density specified in the foreground density column of the selection table PT is determined.

  On the other hand, in the pattern data PD, image data of a corresponding hatch pattern is predetermined for each pattern type such as a vertical line, a horizontal line, a grid line, a diagonal line, and a diagonal grid line. The hatch pattern is, for example, an image of a predetermined size such as 8 × 8 pixels in length and width, and includes at least information indicating a background area and a foreground area in the hatch pattern image area. Accordingly, as will be described later, when the hatch pattern is applied to the image area of the color image by referring to the pattern data PD, the pattern density determination unit 44 determines that the pixel of interest in the image area is the background area. And the foreground area can be determined.

  Next, an outline of processing for applying the hatch pattern P to a color image will be described. Here, as shown in FIG. 5A, a color image CP having a color value of (R, G, B) = (255, 0, 0) over the entire image will be described as an example.

  In the process of applying the hatch pattern P to the color image CP, first, as shown in FIG. 5A, for each unit area UA in which the image area of the color image CP is partitioned by the same size as the hatch pattern P, the hatch pattern P is assigned. At this time, the type of hatch pattern P assigned to the unit area UA is determined according to the pattern selection table PT. According to the pattern selection table PT shown in FIG. 4, the pattern type corresponding to the RGB value of the color image, that is, the color value of (R, G, B) = (255, 0, 0) is “grid line”. Therefore, a “grid line” hatch pattern P is applied to the color image CP in FIG. Accordingly, as shown in FIG. 5B, a grid line hatch pattern P is applied to each unit area UA in the monochrome image MP obtained by converting the color image CP.

  According to the pattern selection table PT of FIG. 4, the pattern type corresponding to the color value of (R, G, B) = (0, 0, 0) is “none”. That is, the hatch pattern P is not applied to an area having a color value of (R, G, B) = (0, 0, 0) in the image area of the color image, (R, G, B) A hatch pattern P is applied to a region having a color value other than (0, 0, 0). Therefore, the area setting unit 42 targets a hatch pattern P to be applied to an area having a color value other than (R, G, B) = (0, 0, 0) among image areas of a color image. The area TA is set (see FIG. 6).

  Further, according to the pattern selection table PT shown in FIG. 4, foreground density is associated with K = 128 and background density is associated with K = 186 with respect to (R, G, B) = (255, 0, 0). Therefore, as shown in FIG. 5B, the density of the foreground area FA of the monochrome image MP is K = 128, and the density of the background area BA is K = 186. Thus, the hatch pattern P determined by the pattern selection table PT and the pattern data PD is applied to the unit area UA. In the present embodiment, the processing according to the table is performed in this way, so that the processing for applying the hatch pattern P to the target area TA of the color image CP is accelerated.

  Here, as described above, when the hatch pattern is applied so that the hatch pattern P is applied to each unit area UA of the color image CP, the hatch pattern may be difficult to see. In FIG. 6A, a part of the target area TA of the color image CP has a color value of (R, G, B) = (255, 0, 0), and other areas have (R, G, B) = ( An example of a color image CP having a color value of (0, 0, 0) is shown. When the lattice pattern hatch pattern P is applied for each unit area UA to the color image CP shown in FIG. 6A, according to the pattern selection table PT of FIG. 4, (R, G, B) = ( Since the hatch pattern P is not applied to the color value of (0, 0, 0), the grid line hatch is performed only for the target area TA having the color value of (R, G, B) = (255, 0, 0). The pattern P is applied. In the example of FIG. 6A, the target area TA is divided into four unit areas UA. Therefore, when the hatch pattern P is applied to each unit area UA, as shown in FIG. In some cases, all of the portions where the lines constituting the line intersect (a “feature portion” described later) do not appear in the target area TA. For this reason, it becomes difficult for the user to distinguish the type of the hatch pattern P of the monochrome image MP only from the image of the target area TA, and it is difficult to distinguish the color of the original color image from the type of hatch pattern.

  FIG. 7 is a diagram showing an example of the characteristic part CA in the hatch pattern P. As shown in FIG. FIG. 7A shows an example of a grid line hatch pattern P, and FIG. 7B shows an example of a horizontal line hatch pattern P. The feature CA of the hatch pattern P refers to a part of the hatch pattern P that allows the user to determine the type of the hatch pattern. For example, in the case of a lattice line hatch pattern P, a region having a predetermined size centering on a portion where lines constituting the lattice line intersect is the feature CA. In the case of the horizontal line hatch pattern P, a region of a predetermined size centering on a part of the line constituting the horizontal line is the feature CA. These feature portions CA are defined so that the user can determine the type of the hatch pattern P from only the patterns in the feature portion CA. That is, the characteristic part CA is an area where the law of the hatch pattern P such as a grid line or a horizontal line appears.

  FIG. 8 is a diagram illustrating a processing example when the hatch pattern P is applied to the color image representing the graph without performing the position correction processing. As shown in FIG. 8A, in the area GA representing the graph, hatch patterns P1 to P4 corresponding to the color of the graph are assigned to the color areas G1 to G4 constituting the graph. Further, as shown in FIG. 8B, which is an enlarged view of the legend area LA of the graph, the legend area LA is also associated with each of the legend color areas L1 to L4 indicating the correspondence with the colors used in the graph. The hatch patterns P1 to P4 corresponding to the colors used in the graph are assigned.

  However, in general, since the area of the legend color area L (L1 to L4) indicating the correspondence with the colors used in the graph is smaller than the area of the area GA representing the graph, the legend color area L includes For example, it may occur that only a part of the patch pattern P shown in FIG. 5 is reflected. In the example of FIG. 8B, for the color regions L1 and L4, not all the lines constituting the hatch pattern P are represented, and the correspondence between the colors used in the graph and the legend cannot be determined. ing. The color region L2 is located in a peripheral region that is deviated from the center of gravity of the color region L2, although all the lines constituting the hatch pattern P are represented. As for the color region L3, only a part of the lines constituting the hatch pattern P is represented, and the appearing lines are also located in the peripheral region deviated from the center of gravity of the color region. For these reasons, it is difficult for the user to determine the hatch pattern P represented in the color areas L1 to L4 of the legend area LA, and it is difficult to associate the graph with the legend.

  Therefore, in the present embodiment, the hatch pattern P is moved so that the feature CA of the hatch pattern P is easy to see in the small regions of the color regions L1 to L4 in the example of FIG. For this reason, the position correction unit 43 performs position correction processing for shifting the feature portion CA of the hatch pattern P toward the center of gravity of the target area TA to which the hatch pattern is applied.

  Therefore, by performing the position correction process described above, as shown in FIG. 9, the feature CA of the hatch pattern P is the center of gravity of the target area TA (the primary moment at the contour of the target area TA is 0). When the target area TA is a point-symmetrical area, a monochrome image MP positioned at the center of the target area TA is generated.

  Next, processing performed by the image processing apparatus 100 described above will be described in detail according to the flowchart of FIG.

  For example, when the printing apparatus driver 40 receives a print instruction for monochrome printing of color image data from the application 30, the process of FIG. 10 is started. When the process is started, the pattern type determination unit 41 sets a target pixel for the image area of the color image data (step S10), and acquires the RGB value of the target pixel from the color image data (step S11).

  Next, the pattern type determination unit 41 refers to the pattern selection table PT and determines a pattern type corresponding to the acquired RGB value (step S12).

  Next, the area setting unit 42 performs a process of setting the target area TA including the target pixel (step S13). Here, a process of scanning pixels around the target pixel and specifying a color image area to which the hatch pattern P is to be applied as the target area TA is performed. In the present embodiment, an area having a color value other than (R, G, B) = (0, 0, 0) according to the pattern selection table PT is the target area TA. For example, in the example of the color image of the graph described with reference to FIG. 8, the color region L representing the color correspondence between the graph and the legend is set as the target region TA. However, the method of setting the target area TA is not limited to this, and the target area TA may be set by scanning the entire color image at a timing before setting the target pixel. Further, the determination method of the target area TA is not limited to the area other than (R, G, B) = (0, 0, 0), but is larger than a predetermined RGB value, for example. An area having RGB values may be determined as the target area TA.

  Next, the position correction unit 43 determines whether or not the target area TA including the target pixel is smaller than a predetermined size (step S14).

When the target area TA including the target pixel is larger than the predetermined size (step S14: No), the process proceeds to step S16 without performing the position correction process, and the pattern density determining unit 44 determines that the target pixel is hatched. It is determined whether or not it corresponds to the background of the pattern P. As described with reference to FIG. 5, since the hatch pattern P is assigned to each unit area UA in the image area of the color image, here, in the hatch pattern P in which the coordinates of the target pixel are assigned to each unit area UA. It is determined whether the current position is in the position corresponding to the background or the position corresponding to the foreground. Specifically, as shown in FIG. 11, when the coordinates of the target pixel are (a, b) and the size of the hatch pattern P is N × N pixels, the relative coordinates (x, y) of the target pixel in the hatch pattern P ) Is obtained by the following equations (1) and (2). The pattern density determination unit 44 refers to the image data of the hatch pattern P in the pattern data PD and determines whether the relative coordinates (x, y) of the target pixel corresponds to the background or the foreground in the hatch pattern P. . In the following formula, “mod” is an operator that returns the remainder after division.
x = a mod N (1)
y = b mod N (2)

  When the target pixel corresponds to the background (step S16: Yes), the pattern density determination unit 44 refers to the pattern selection table PT and acquires the K value of the background density corresponding to the RGB value of the target pixel (step S17). ). On the other hand, when the target pixel corresponds to the foreground region (step S16: No), the pattern density determination unit 44 refers to the pattern selection table PT and acquires the K value of the foreground density corresponding to the RGB value of the target pixel. (Step S18). In the example of FIG. 11, since the relative coordinates (x, y) corresponding to the target pixel (a, b) correspond to the foreground area FA of the hatch pattern P, the K value of the foreground density with respect to the target pixel is Will be acquired.

On the other hand, if it is determined in step S14 that the target area TA including the target pixel is smaller than the predetermined size (step S14: Yes), the position correction unit 43 performs position correction processing (step S15). FIG. 12 is a conceptual diagram of the position correction process. As shown in FIG. 12, when the position correction process is not performed, the center coordinates of the feature portion CA of the hatch pattern P assigned to the unit area UA are (X1, Y1), and the center coordinates of the target area TA are (X2, Y2). Assuming that Y2), the positional deviation amounts (ΔX, ΔY) between the feature part CA and the target area TA are obtained by the following equations (5) and (6). In the position correction process, the center of the hatched pattern feature TA is shifted to the center of gravity of the target area TA by moving the hatched pattern P using the amount of displacement (ΔX, ΔY) as a correction amount.
ΔX = X2−X1 (5)
ΔY = Y2−Y1 (6)

  When the position correction process is performed, the pattern density determination unit 44 determines whether the target pixel corresponds to the background of the hatched pattern P after the shift (step S16), and if it corresponds to the background (step S16: Yes), the background density is acquired with reference to the pattern selection table PT (step S17). If it does not correspond to the background, that is, corresponds to the foreground (step S16: No), the foreground density is acquired with reference to the pattern selection table PT (step S18).

  In step S17 or step S18, when the pattern density determination unit 44 acquires the K value of the background density or foreground density, the monochrome image data generation unit 45 acquires the pixel corresponding to the target pixel in the image area of the monochrome image. The K value of the density is reflected (step S19). Thereby, the pixel of the monochrome image corresponding to the target pixel has a K value of density corresponding to the type of hatch pattern P determined in step S12.

  The position correction process described above can also be realized by coordinate conversion of the target pixel. For example, as described with reference to FIG. 12, when shifting the correction amount of the hatch pattern P by the amount of positional deviation (ΔX, ΔY), the relative coordinates (x , Y) by determining whether the coordinates moved by the correction amount are the background area BA or the foreground area FA, thereby determining whether the pixel of interest is the background area BA or the foreground area FA. Can do. As described above, when the position correction process is realized by the coordinate conversion of the coordinates used when referring to the pattern data PD, the calculation required for the position correction process is larger than when the image data of the shifted hatch pattern P is actually generated. The amount is reduced and the processing speed is increased.

  When the background or foreground density is reflected on the target pixel, the monochrome image data generation unit 45 determines whether or not the processing in steps S10 to S19 has been performed on all pixels of the color image (step S20). . If the processing has not been completed for all pixels (step S20: No), the process returns to step S10, for example, a new pixel of interest is set by scanning the pixel of interest in the raster direction, and the step is performed for the new pixel of interest The process after S11 is performed. When the processing is completed for all the pixels (step S20: Yes), all the pixels of the monochrome image have a K value having a density corresponding to the type of hatch pattern P determined in step S12. The data generation unit 45 generates monochrome image data of this monochrome image (step S21). The generated monochrome image data is output to the printing apparatus 20 by the printing apparatus driver 40 (step S22). As a result, a monochrome image with a hatch pattern corresponding to the color of the color image is printed as monochrome printing of the color image data delivered from the application 30.

  FIG. 13 shows an example of a monochrome image print result. As shown in FIG. 13, the position correction processing is performed on the color regions L ′ (L1 ′ to L4 ′) included in the legend area LA as compared with the case where the position correction processing described in FIG. 8B is not performed. As a result, a print result in which a line constituting the characteristic portion CA of the hatch patterns P1 to P4 is drawn at the center of gravity of the color region L ′.

  According to the image processing apparatus 100 of the present embodiment, monochrome image data in which the hatch pattern P is hatched according to the color of the color image is generated from the color image data. Further, by the position correction process, the hatched pattern feature CA is shifted to the center of gravity of the target area TA in the target area TA to which the hatch pattern P is applied. As a result, as shown in FIG. 13, the feature portion CA of the hatch pattern P appears at the center of gravity of the target area TA. Therefore, the user can easily discriminate the pattern type even in a predetermined area having a small area, and can distinguish the color difference, thereby improving user convenience.

  The original image is regenerated as image data to which a pattern corresponding to the color information of the original image is applied. Therefore, by distinguishing the type of pattern represented in the regenerated image data, it becomes possible to easily distinguish the color difference in the original image, and the user convenience is improved.

  The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and can be changed and improved without departing from the spirit and scope of the claims. Of course, the equivalent is included. Hereinafter, modified examples will be described.

  (Modification 1) In the above embodiment, in the position correction process, the feature CA is shifted to the center of gravity of the target area TA by moving it by the amount of positional deviation between the feature CA of the hatch pattern P and the target area TA. However, the present invention is not limited to this, and the feature CA may be shifted toward the center of gravity of the target area TA. For example, the hatch pattern may be moved so that the feature CA of the hatch pattern P falls within a range that is a predetermined distance from the center of gravity of the target area TA.

  (Modification 2) In the above embodiment, the position correction process is performed on the target area TA smaller than the predetermined size. However, the method of determining the area on which the position correction process is performed is not limited to this. Regardless of the size, the position correction process may be performed on all target areas, or the type of the area such as the legend area LA may be determined, and the position correction process may be performed according to the type.

  (Modification 3) In the above embodiment, the case where color image data is converted into monochrome image data with a hatch pattern has been described. However, the converted image data is not limited to monochrome image data, and color image data It may be. For example, when converting color image data in RGB format into color image data in CMYK format, a color image with a hatch pattern can be printed by a printing apparatus or the like. The color of the original color image is represented by the hatch pattern. Further, when converting RGB color image data to RGB color image data with a hatch pattern, a color image with a hatch pattern can be displayed on a display device such as a display. Thus, by making a color image with a hatch pattern, not only a healthy person but also various users including a color blind person can distinguish the color difference from the hatch pattern.

  (Modification 4) In the above embodiment, the position correction process is performed when the target area TA is smaller than the predetermined size. However, the target area TA is smaller than the minimum size that can distinguish the pattern type. In this case, it is desirable not to perform the position correction process. In this way, since the target area TA is small, the position correction process is omitted when the pattern cannot be determined even if the position correction process is performed, so that the process can be performed more efficiently. .

  (Modification 5) In the above embodiment, the color image data is converted into the monochrome image data with the hatch pattern by the processing on the computer 10 side, but may be converted by the internal processing of the printing apparatus. . For example, as illustrated in FIG. 14, the controller 22 of the printing apparatus includes a pattern type determination unit 41, a region setting unit 42, a position correction unit 43, a pattern density determination unit 44, a monochrome image data generation unit 45, and a print processing unit 23. Functions as an image processing apparatus. The pattern type determination unit 41, the position correction unit 43, the pattern density determination unit 44, and the monochrome image data generation unit 45 perform the same processing as that of the above embodiment on the color image data transmitted from the computer. The print processing unit 23 performs halftone processing or the like on the monochrome image data with the hatch pattern, and outputs it to the print engine 21, thereby printing a monochrome image that can distinguish the color difference in the original color image. The

  Further, the computer and the printing apparatus may cooperate to convert to monochrome image data. For example, in the system shown in FIG. 14, the printer driver 40 of the computer prints color image data to which designation information designating parameters such as pattern type, background density, and foreground density is added with reference to the pattern selection table PT. Send to device. The pattern type determination unit 41 of the printing apparatus may determine the pattern type according to the designation information added to the color image data, and the pattern density determination unit 44 may determine the background density and the foreground density according to the designation information.

  (Modification 6) In the above embodiment, the hatch pattern P is used as the pattern to be applied to the color image, but the present invention is not limited to this. A pattern other than a hatch pattern may be applied as long as the pattern has a predetermined regularity.

  (Modification 7) In the above embodiment, the hatch pattern P to be applied to the color image is assigned to each color region indicating the correspondence between the color used in the graph and the legend. However, the present invention is not limited to this. The embodiment described above may be applied if the area is small so that not all of the pattern can be expressed in the area and only a part of the pattern can be expressed. In addition, the above embodiment may be applied to an area for explaining the meaning of symbols and the like used in the chart and the contents drawn in the chart. In this way, even if the area where the pattern and contents appear is small, the user can easily distinguish the color correspondence from the pattern.

  DESCRIPTION OF SYMBOLS 1 ... Printing system, 10 ... Computer, 20 ... Printing apparatus, 21 ... Printing engine, 22 ... Controller, 30 ... Application, 40 ... Printing device driver, 41 ... Pattern type determination part, 42 ... Area setting part, 43 ... Position correction , 44... Pattern density determination unit, 45... Monochrome image data generation unit as image data generation unit, 100... Image processing device, PT... Pattern selection table as correspondence information, PD ... pattern data, P ... hatch pattern, CA ... characteristic part, TA ... target area.

Claims (8)

A pattern type determination unit for determining a predetermined pattern corresponding to the color information of the image;
An area setting unit for setting a predetermined area in the image;
A position correction unit that corrects a positional relationship between the feature part that can determine the type of the pattern included in the pattern determined by the pattern type determination part and the region set by the region setting unit;
An image data generation unit for generating image data including the image and the pattern,
The application position of the characteristic part in the region is corrected toward the center of gravity of the region by the position correction unit. The image processing apparatus according to claim 1.
The image processing apparatus according to claim 1, wherein when the area is equal to or more than a minimum unit capable of representing the feature portion, the application position of the feature portion is corrected. The image processing apparatus according to claim 1 or 2,
The image processing apparatus, wherein the density of the pattern and / or the density of the image is changed by the image data generation unit corresponding to the color information. In the image processing device according to any one of claims 1 to 3,
An image processing apparatus, further comprising: a storage unit that stores correspondence information in which the color information is associated with a number of patterns smaller than the number of the color information. In the image processing device according to any one of claims 1 to 4,
An image processing apparatus, wherein the area is an area indicating a legend. In the image processing device according to any one of claims 1 to 5,
The image processing apparatus according to claim 1, wherein the image data is monochrome image data. Determining a predetermined pattern corresponding to the color information of the image;
Setting a predetermined region in the image;
Correcting the positional relationship between the feature that can discriminate the pattern type included in the determined pattern and the set region;
Generating image data including the image and the pattern, and
An image processing method, wherein the application position of the feature in the region is corrected toward the center of gravity of the region. Computer
A pattern type determination unit for determining a predetermined pattern corresponding to the color information of the image;
An area setting unit for setting a predetermined area in the image;
A position correction unit that corrects a positional relationship between a feature part that can determine a type of the pattern included in the pattern determined by the pattern type determination unit, and the area set by the area setting unit;
Function as an image data generation unit for generating image data including the image and the pattern,
An image processing program that corrects an application position of the feature in the region toward the center of gravity of the region by the position correction unit.