JP6233092B2 - Control device and computer program - Google Patents

Description

  The present invention relates to a control device and a computer program for controlling a printing apparatus.

  In a printing device that prints an image, if the upper limit value of component color density that can be formed by the printing device becomes lower, the gradation change cannot be reproduced in an area that is higher than the upper limit value of component color formation density, resulting in gradation collapse. To do.

  Then, in a printing apparatus that expresses gray with cyan, magenta, and yellow component colors, the output density value is uniformly compressed by compressing the output density value of the component color uniformly with the compression ratio between the formation density upper limit value and the maximum gray density in the component color. A technique is known that corrects a value and suppresses occurrence of gradation collapse without causing gray balance collapse (see, for example, Patent Document 1).

JP 2007-36885 A

  However, in the technique described in Patent Document 1, since the output density value of the component color is uniformly compressed at the compression ratio, the output density value may not be corrected to an appropriate output density value depending on the gradation value of the component color. Is concerned.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a technique that makes it possible to perform appropriate correction for each gradation value in the case where occurrence of gradation collapse is suppressed.

The control device of the present invention made to achieve the above object includes first storage control means, acquisition means, first calculation means, correction means, second calculation means, and setting means.
Here, the minimum gradation value that can be printed in the printing apparatus that prints an image is defined as the minimum gradation value. The maximum gradation value that can be printed in the printing apparatus is defined as the maximum gradation value. A value corresponding to the target brightness when the image of the minimum gradation value is printed by the printing apparatus is set as the minimum target brightness value. A value corresponding to the target luminance when the image of the maximum gradation value is printed by the printing apparatus is set as the maximum target luminance value. The first storage control unit stores information indicating the minimum target luminance value and the maximum target luminance value in advance in the storage unit of the control device.

  Further, based on the measurement result obtained by measuring the brightness of the patch image printed by the printing apparatus, a value corresponding to the brightness when the image of the minimum gradation value is printed on the printing apparatus is set as the minimum colorimetric brightness value. Based on the measurement result, a value corresponding to the luminance when the image of the maximum gradation value is printed on the printing apparatus is set as the maximum colorimetric luminance value. The obtaining unit obtains information indicating the minimum colorimetric luminance value and the maximum colorimetric luminance value.

  Further, a gradation value that can be printed by the printing apparatus and is different from the minimum target luminance value and the maximum target luminance value is set as the first gradation value. A gradation value that can be printed by the printing apparatus and is different from the minimum target luminance value, the maximum target luminance value, and the first gradation value is set as the second gradation value. A value corresponding to the target brightness when the printing apparatus prints an image having the first gradation value is set as the first target brightness value. A value corresponding to the target brightness when the image of the second gradation value is printed by the printing apparatus is set as the second target brightness value. The difference between the minimum colorimetric luminance value and the maximum colorimetric luminance value is defined as the colorimetric luminance range. Then, the first calculation means includes a first colorimetric ratio that is a ratio of the first target luminance value to the colorimetric luminance range, and a second colorimetric ratio that is a ratio of the second target luminance value to the colorimetric luminance range. calculate.

  Further, a difference between the minimum target luminance value and the maximum target luminance value is set as a target luminance range. A ratio of the first target luminance value to the target luminance range is set as a first target ratio. A ratio of the second target luminance value to the target luminance range is set as a second target ratio. Then, the correcting unit performs a correction for bringing the first colorimetric ratio close to the first target ratio, and performs a correction for bringing the second colorimetric ratio close to the second target ratio.

  In addition, the first colorimetric ratio corrected by the correcting unit is set as the first corrected colorimetric ratio. The second colorimetric ratio corrected by the correcting means is set as the second corrected colorimetric ratio. The corrected value of the first target luminance value is set as the first corrected target luminance value. The corrected value of the second target luminance value is set as the second corrected target luminance value. Then, the second calculation means calculates the first correction target luminance value so that the ratio of the first correction target luminance value to the colorimetric luminance range becomes the first correction colorimetric ratio, and the second correction target for the colorimetric luminance range. The second corrected target luminance value is calculated so that the luminance value ratio becomes the second corrected colorimetric ratio.

  The setting unit sets a value corresponding to a target brightness when the printing apparatus prints an image having the first gradation value as the first corrected target brightness value, and prints an image having the second gradation value on the printing apparatus. A value corresponding to the target luminance when the correction is performed is set as the second corrected target luminance value.

  In the control device of the present invention configured as described above, the first colorimetry after correction is performed by performing correction so that the first colorimetry ratio and the second colorimetry ratio are close to the first target ratio and the second target ratio, respectively. The ratio (first corrected colorimetric ratio) and the corrected second colorimetric ratio (second corrected colorimetric ratio) can be set to a value of 100% or less. The ratio of the first correction target luminance value to the colorimetric luminance range is the first corrected colorimetric ratio. Similarly, the ratio of the second corrected target luminance value to the colorimetric luminance range becomes the second corrected colorimetric ratio. For this reason, according to the control device of the present invention, the first correction target luminance value and the second correction target luminance value can be set as values included in the colorimetric luminance range, and in the case where the occurrence of gradation collapse is suppressed. Appropriate correction can be performed for each gradation value.

  Also, a control method, a computer program, and a computer-readable recording medium storing the computer program for realizing the control device are novel and useful. The computer-readable recording medium may be portable or may be preinstalled in a computer. Further, the computer program of the present invention may be loaded into a computer via a network.

1 is a block diagram illustrating a configuration of a printing system 1. FIG. It is a flowchart which shows a table creation process. It is a figure which shows the correspondence of a target color, a colorimetric value, and a gradation value. It is a figure which shows the correspondence of an allowable width | variety and a gradation value. It is a figure which shows the calculation method of the colorimetric value ratio after correction | amendment. It is a figure which shows the correspondence of the target color and gradation value before and behind correction | amendment.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the printing system 1 of the present embodiment includes a print control device 2, a multi-function peripheral device (hereinafter referred to as MFP 3), and a personal computer 4 (hereinafter referred to as PC 4). The print control apparatus 2, MFP 3, and PC 4 are connected via a communication line 5 so that they can communicate with each other.

  The print control apparatus 2 includes a communication unit 11, a data storage unit 12, and a control unit 13. The communication unit 11 performs data communication between the MFP 3 and the PC 4 via the communication line 5. The data storage unit 12 is a storage device for storing various data. The control unit 13 includes a CPU 21, a ROM 22, and a RAM 23, and controls the communication unit 11 and the data storage unit 12 when the CPU 21 executes a process based on a program stored in the ROM 22.

The MFP 3 includes a communication unit 31, a printing unit 32, a reading unit 33, and a control unit 34.
The communication unit 31 performs data communication with the print control apparatus 2 via the communication line 5. The printing unit 32 is a known device that prints an image in monochrome on a sheet fed from a predetermined sheet feeding position. The reading unit 33 is a well-known device that reads an image from a sheet placed on a predetermined document table and generates read data representing the image. The control unit 34 executes various processes based on the input from the communication unit 31 and controls the communication unit 31, the printing unit 32, and the reading unit 33.

The PC 4 is a general-purpose information processing apparatus, and includes a communication unit 41, a display unit 42, an operation input unit 43, a data storage unit 44, and a control unit 45.
The communication unit 41 performs data communication with the print control apparatus 2 via the communication line 5. The display unit 42 includes a display device (not shown) and displays various images on the display screen of the display device. The operation input unit 43 outputs input operation information for specifying an input operation performed by a user via a keyboard (not shown) and a mouse (not shown). The data storage unit 44 is a storage device for storing various data. The control unit 45 executes various processes based on inputs from the communication unit 41 and the operation input unit 43 and controls the communication unit 41, the display unit 42, and the data storage unit 44.

  When the PC 4 inputs input operation information indicating a print request operation by the user from the operation input unit 43, the PC 4 issues a print command for requesting printing of image data specified by the input operation information to image data to be printed (hereinafter referred to as print data). And the print image data) to the print control apparatus 2.

  In addition, the print control apparatus 2 stores the monochrome target color table 26 in the data storage unit 12. In the monochrome target color table 26, the correspondence relationship between the gradation value of the image data and the brightness when the MFP 3 prints with this gradation value is determined in advance (see the curve L1 in FIG. 3). Hereinafter, the luminance determined in the monochrome target color table 26 is also referred to as a target color. Further, the print control apparatus 2 stores each target color ratio and each target color ratio range for each gradation value in the data storage unit 12. Each target color ratio satisfies Expression (2) described later.

  Upon receiving a print command from the PC 4, the print control apparatus 2 converts the gradation value of each pixel constituting the print image data into a corresponding luminance based on the monochrome target color table 26 and outputs it to the MFP 3. This causes the MFP 3 to print an image in monochrome.

In the printing system 1 configured as described above, the control unit 13 of the print control apparatus 2 executes table creation processing.
Here, the procedure of the table creation process executed by the control unit 13 will be described. The table creation process is executed when a command requesting execution of the table creation process is received from the PC 4.

  When this table creation processing is executed, the control unit 13 first transmits a command requesting printing of a patch image to the MFP 3 in S10 as shown in FIG. As a result, the MFP 3 prints and outputs the patch image on the paper. The patch image is an image obtained by arranging images corresponding to each of a plurality of gradation values and printing them on a sheet.

  In step S20, it is determined whether the colorimetric result of the patch image has been received from the MFP 3. The color measurement result of the patch image is acquired by causing the reading unit 33 of the MFP 3 to read the patch image printed by the MFP 3. The color measurement result of the patch image indicates a result of measuring the luminance of the image corresponding to each of a plurality of gradation values in the patch image.

  If the colorimetric result of the patch image has not been received (S20: NO), the process of S20 is repeated to wait until the colorimetric result of the patch image is received. When the colorimetric result of the patch image is received (S20: YES), the colorimetric result of the patch image is stored in the RAM 23, and in S30, an integer from 0 to 255 is based on the colorimetric result of the patch image. The brightness corresponding to each determined gradation value is specified (see curve L2 in FIG. 3). Hereinafter, the luminance specified in S30 is also referred to as a colorimetric value.

  Thereafter, in S40, a variable i (hereinafter referred to as gradation value i) stored in the RAM 23 is designated as 0 in order to designate the gradation value in the table creation process. In S50, it is determined whether or not the gradation value i stored in the RAM 23 is 256. If the gradation value i is not 256 (S50: NO), the colorimetric value ratio for the gradation value i is calculated in S60. Hereinafter, the colorimetric value ratio at the gradation value i is referred to as a colorimetric value ratio [i].

  Here, the colorimetric value when the gradation value is 0 is expressed as a colorimetric value [0] (see point P1 in FIG. 3), and the colorimetric value when the gradation value is 255 is colorimetric. If it is expressed as value [255] (see point P2 in FIG. 3) and the target color when the gradation value is i is expressed as target color [i] (see point P3 in FIG. 3), then the colorimetric value The ratio [i] is calculated by the following equation (1).

In step S70, the target color ratio at the gradation value i is acquired from the data storage unit 12. Hereinafter, the target color ratio at the gradation value i is expressed as target color ratio [i].
Here, the target color when the gradation value is 0 is referred to as target color [0] (see point P4 in FIG. 3), and the target color when the gradation value is 255 is the target color [255]. (See point P2 in FIG. 3), the target color ratio [i] satisfies the following expression (2).

In S80, the target color ratio range at the gradation value i is acquired from the data storage unit 12. Hereinafter, the target color ratio range at the gradation value i is referred to as a target color ratio range [i].
Here, when the maximum value of the target color ratio range [i] is expressed as Max [i] and the minimum value of the target color ratio range [i] is expressed as Min [i], the target color ratio range [i] The range is greater than Min [i] and less than Max [i].

When the allowable width at the gradation value i is expressed as R [i], Max [i] and Min [i] satisfy the following expressions (3) and (4), respectively.
Max [i] = target color ratio [i] + R [i] (3)
Min [i] = target color ratio [i] −R [i] (4)
However, Max [i] and Min [i] are set so as to satisfy the relationship shown in the following expression (5).

0 ≦ Min [i] ≦ Max [i] ≦ 1 (5)
In the present embodiment, the allowable width R [i] is lower when the gradation value is 135 to 254 so that the following expression (6) is satisfied when the gradation value is 0 to 134. In order to satisfy Expression (7), when the gradation value is 255, it is determined in advance to be 0 (see FIG. 4). In other words, the allowable width in the intermediate gradation (for example, gradation values of 105 to 149) is low gradation (for example, gradation values of 0 to 44) and high gradation (for example, gradation values of 210 to 255). Etc.) and to be wider than the allowable range. Generally speaking, the difference (for example, 50) between 0, which is the minimum gradation value, and the first gradation value (for example, gradation value 50) is 255, which is the maximum gradation value. It is smaller than the difference (for example, 205) from the first gradation value (for example, gradation value 50) and is the minimum gradation value 0 and the second gradation value (for example, gradation value is 100). ) (For example, 100) is smaller than the difference (for example, 155) between 255, which is the maximum gradation value, and the second gradation value (for example, gradation value 100), and the first When the gradation value (for example, the gradation value is 50) is smaller than the second gradation value (for example, the gradation value is 100), the allowable width R [50] (that is, 0.03) is the allowable width. Narrower than [100] (ie 0.06).

  Further, the allowable range is 0 in the gradation value range (0 to 14) including 0 which is the minimum gradation value and the gradation value range (240 to 255) including 255 which is the maximum gradation value. Has been determined.

  In S90, the colorimetric value ratio [i] is corrected so that the colorimetric value ratio [i] is included in the target color ratio range [i], and the corrected colorimetric value ratio [i] is stored in the RAM 23. To remember. Hereinafter, the corrected colorimetric value ratio [i] is also referred to as a corrected colorimetric value ratio [i].

  The specific process of S90 will be described. First, when the colorimetric value ratio [i] is included in the target color ratio range [i], the colorimetric value ratio [i] is set as the corrected colorimetric value ratio [i] (measurement of FIG. 5). See color value ratio MR1).

  If the colorimetric value ratio [i] is greater than Max [i] (see the colorimetric value ratio MR2 in FIG. 5), Max [i] is set to the corrected colorimetric value ratio [i] (see FIG. 5). 5 arrow AL1 and colorimetric value ratio MR3). In this case, the corrected colorimetric value ratio [i] is Max [i], which is a value close to the target color ratio [i] with respect to the original colorimetric value ratio [i]. Therefore, in general, this correction process is a process for correcting the colorimetric value ratio [i] to be close to the target color ratio [i].

  When the colorimetric value ratio [i] is smaller than Min [i], Min [i] is set as the corrected colorimetric value ratio [i]. In this case, the corrected colorimetric value ratio [i] is Min [i], which is a value close to the target color ratio [i] with respect to the original colorimetric value ratio [i]. Therefore, in general, this correction process is a process for correcting the colorimetric value ratio [i] to be close to the target color ratio [i].

  The allowable width R [0] and the allowable width R [255] are zero. Therefore, the corrected colorimetric value ratio [0] and the corrected colorimetric value ratio [255] are the target color ratio [0] and the target color ratio [255], respectively.

  In step S100, the target color [i] is corrected based on the corrected colorimetric value ratio [i], and the corrected target color [i] is stored in the RAM 23. Hereinafter, the corrected target color [i] is also referred to as a corrected target color [i]. The specific process of S100 includes a process of calculating the corrected target color [i] as shown in the following equation (8).

Thereafter, in S110, the gradation value i is incremented, and the process proceeds to S50. More specifically, the gradation value i stored in the RAM 23 is incremented by 1, and the variable is updated.
If the gradation value i is 256 in S50 (S50: YES), the corrected target color [i] in which the gradation value i calculated so far is 0 to 255 in S120. Thus, the monochrome target color table 26 is corrected using each corrected target color [i] stored in the RAM 23, and a new monochrome target color table 26 is created. Specifically, for each gradation value i from 0 to 255, the target color [i] in the monochrome target color table 26 (see curve L1 in FIG. 6) is replaced with the corrected target color [i]. (See arrow AL2 in FIG. 6) is set as a new monochrome target color table 26 (see curve L3 in FIG. 6). Further, the process of creating the new monochrome target color table 26 as described above is generally a process of setting a value corresponding to the target brightness when the image is printed on the MFP 3 as the corrected target brightness value. It is.

When the process of S120 ends, the table creation process ends.
The new monochrome target color table 26 is a table created based on the print result of the MFP 3. Therefore, it should be used in the MFP 3 and an apparatus equivalent to the MFP 3 (for example, MFPs of the same model or model number). Accordingly, the new monochrome target table 26 stored in the data storage unit 12 may be transmitted to the MFP 3 via the communication unit 11. In this case, when the printing unit 32 performs printing, the control unit 34 may use the processing for converting the gradation value of each pixel constituting the print image data into the corresponding luminance.

  Further, the new monochrome target table 26 stored in the data storage unit 12 may be uploaded to a server on the Internet such as an external cloud server via the communication unit 11. In this case, when the printing unit of the equivalent device is downloaded from the external cloud server by the device equivalent to the MFP 3 and the printing unit of the equivalent device performs printing, the control unit of the equivalent device performs the processing of each pixel constituting the print image data. You may use a tone value for the process which converts into a corresponding brightness | luminance.

  In the printing control apparatus 2 of the printing system 1 configured as described above, the control unit 13 previously stores information indicating each target color [i] including the target color [0] and the target color [255] in advance. Is stored in the data storage unit 12.

  Further, the print control device 2 specifies information indicating the colorimetric value [0] and the colorimetric value [255] (S30), and the colorimetric value ratio [i] (i = 0, 1, 2,..., 255) is calculated (S60). Further, the print control apparatus 2 performs correction to bring the colorimetric value ratio [i] close to the target color ratio [i] (S90), and calculates the corrected target color [i] (S100).

Then, the print control apparatus 2 sets the target color [i] in the monochrome target color table 26 to the corrected target color [i] (S120).
In the print control apparatus 2 configured as described above, the correction is performed by correcting the colorimetric value ratio [i] (i = 0, 1, 2,..., 255) to the target color ratio [i]. The post-colorimetric value ratio [i] can be set to a value of 100% or less. The ratio of the corrected target color [i] to the range from the colorimetric value [0] to the colorimetric value [255] (hereinafter referred to as the colorimetric luminance range) is the corrected colorimetric value ratio [i]. For this reason, according to the print control apparatus 2, the corrected target color [i] can be set to a value included in the colorimetric luminance range, and appropriate correction is performed for each gradation value when the occurrence of gradation collapse is suppressed. It can be performed.

  Further, the print control apparatus 2 performs correction to bring the colorimetric value ratio [i] (i = 0, 1, 2,..., 255) closer to the target color ratio [i], thereby correcting the colorimetric value ratio after correction. The ratio (j ≠ k) of the corrected colorimetric value ratio [k] to [j] can be brought close to the ratio of the target color [k] to the target color [j]. Therefore, according to the print control apparatus 2, the balance between the luminance of the image when the MFP 3 prints the image having the gradation value j and the luminance of the image when the MFP 3 prints the image having the gradation value k. However, it is possible to suppress the occurrence of a situation where the target color [j] and the target color [k] are lost due to the correction.

  Further, the print control apparatus 2 performs correction for bringing the colorimetric value ratio [i] (i = 0, 1, 2,..., 255) closer to the target color ratio [i], thereby correcting the target color [j ] For the target color [j] and the target color [k] so that the ratio of the target color [k] to the corrected target color [k] is different from each other (j ≠ k). Correction can be performed. Therefore, according to the print control apparatus 2, the target color [j] and the target color [j] are set to appropriate values according to the gradation value j and the gradation value k for each of the gradation value j and the gradation value k. k] can be corrected.

  Further, in the print control apparatus 2, when the colorimetric value ratio [i] is not included in the target color ratio range [i] (i = 0, 1, 2,..., 255), the colorimetric value ratio [ i] is included in the target color ratio range [i], thereby correcting the colorimetric value ratio [i] to be close to the target color ratio [i] (S90). Thereby, the colorimetric value ratio [i] can be corrected by a simple method of including the colorimetric value ratio [i] within the target color ratio range [i].

  In the printing control apparatus 2, when the gradation value is 0 to 134, the allowable width R [i] is determined so as to satisfy the above expression (6). As a result, in the vicinity of the low gradation, correction is performed to bring the colorimetric value ratio closer to the target color ratio, and the target color can be brought closer to the value close to the colorimetric value. can do. Further, in the intermediate gradation, the possibility that the colorimetric value ratio is not corrected increases, and the original target color can be used as much as possible.

  In the print control device 2, when the colorimetric value ratio [i] is included in the target color ratio range [i] (i = 0, 1, 2,..., 255), the colorimetric value ratio [i] ] Is the corrected colorimetric value ratio [i]. As a result, when the colorimetric value ratio [i] is included in the target color ratio range [i], the corrected target color [i] is the target color [i]. For this reason, according to the printing control apparatus 2, it is possible to suppress the occurrence of gradation collapse without changing the target color [i] before correction as much as possible.

  In the print control apparatus 2, the control unit 13 stores the target color [i] (i = 0, 1, 2,..., 255) in the data storage unit 12 in advance. Therefore, according to the print control apparatus 2, when the corrected target color [i] is calculated, information indicating the target color [i] has only to be acquired from the data storage unit 12, and thus the target color [i] is determined. There is no need to calculate, and the processing load of the print control apparatus 2 can be reduced.

  In the print control apparatus 2, the corrected target color [255] is set to the colorimetric value [255], and the corrected target color [0] is set to the colorimetric value [0]. Accordingly, it is not necessary to newly calculate the corrected target color [255] and the corrected target color [0] in order to suppress occurrence of gradation collapse, and the processing load on the printing control apparatus 2 is reduced. can do.

  In the printing control apparatus 2, the control unit 13 stores the target color ratio [i] (i = 0, 1, 2,..., 255) in the data storage unit 12 in advance. For this reason, according to the print control apparatus 2, when the target color ratio [i] is calculated, information indicating the target color ratio [i] may be acquired from the data storage unit 12, and thus the target color ratio [i] Need not be calculated, and the processing load on the print control apparatus 2 can be reduced.

  In the embodiment described above, the print control device 2 is the control device according to the present invention, the MFP 3 is the printing device according to the present invention, the data storage unit 12 is the storage unit according to the present invention, the control unit 13 is the first storage control means according to the present invention, The process of S30 is the acquisition means in the present invention, the process of S60 is the first calculation means in the present invention, the process of S90 is the correction means in the present invention, the process of S100 is the second calculation means in the present invention, and the process of S120 is the present invention. The setting means and the control unit 13 are the second storage control means in the present invention, and the control unit 13 is the third storage control means in the present invention.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, As long as it belongs to the technical scope of this invention, a various form can be taken.
For example, in the above embodiment, the print control apparatus 2 and the MFP 3 are connected via the communication line 5 so as to be capable of data communication. However, the print control apparatus 2 may be built in the MFP 3.

In the above embodiment, the target color is corrected using the luminance corresponding to each gradation value. However, the density may be used instead of the luminance.
In the above-described embodiment, the colorimetric value ratio [i] is included in the target color ratio range [i], thereby correcting the colorimetric value ratio [i] to be close to the target color ratio [i]. Showed things. However, by setting the allowable width R [i] (i = 0, 1, 2,..., 255) to 0, the colorimetric value ratio [i] matches the target color ratio [i]. Correction may be performed.

  In the above embodiment, the target color ratio [i] is acquired from the data storage unit 12 (S70). However, the target color ratio [i] may be calculated by the above equation (2) using the target color [i] determined in the monochrome target color table 26.

  In the above embodiment, the target color [i] (i = 0, 1, 2,..., 255) is stored in advance in the data storage unit 12 as the monochrome target color table 26. However, a mathematical expression representing the target color [i] may be stored in the data storage unit 12 in advance, and the target color [i] may be calculated using the mathematical expression when executing the table creation process. Further, the target color [255], the target color [0], and the mathematical formula are stored in the data storage unit 12 in advance, and the target color [i] (i = 1, 2,... 254) may be calculated by a mathematical expression.

  In the above embodiment, the print control apparatus 2, MFP 3, and PC 4 are configured as separate apparatuses. However, the print control apparatus 2, the MFP 3, and the PC 4 may be configured as a single apparatus.

In the above embodiment, the MFP 3 includes the reading unit 33. However, the reading unit 33 may be incorporated in the printing system 1 as a device different from the MFP 3.
In the above embodiment, the printing unit 32 prints in monochrome. However, the printing unit 32 may print in color, and the above processing may be performed on each color of CMYK or RGB.

  In the above embodiment, the target color ratio range [i] is stored in the data storage unit 12 in advance, and the target color ratio range [i] is acquired from the data storage unit 12 in S80. However, the value of the allowable width R [i] is stored in the data storage unit 12 in advance, and the target color ratio is calculated by the above equations (3) and (4) using the allowable width R [i] acquired from the data storage unit 12. The range [i] may be calculated.

  In the above-described embodiment, the new monochrome target color table 26 is created by replacing the target color [i] with the corrected target color [i] in S120. However, another new monochrome target color table may be created using the corrected target color [i] without replacing the monochrome target color table 26.

  In the above embodiment, the monochrome storage color table 26 is stored in the data storage unit 12. However, the new monochrome target color table 26 created in S120 may be stored in a separate storage medium (for example, a USB memory) connected to the print control apparatus 2.

  In the above-described embodiment, in S <b> 30, the luminance corresponding to each gradation value determined by an integer from 0 to 255 based on the color measurement result of the patch image is shown. However, only the luminance corresponding to each gradation value determined by integers of 0 and 255 may be specified. In this case, the control unit 13 may store only the information indicating the target color [0] and the target color [255] in the data storage unit 12 of the print control apparatus 2 in advance.

  DESCRIPTION OF SYMBOLS 1 ... Printing system, 2 ... Print control apparatus, 3 ... MFP, 4 ... PC, 5 ... Communication line, 11, 31, 41 ... Communication part, 12, 44 ... Data storage part, 13, 34, 45 ... Control part, 26 ... monochrome target color table, 32 ... printing unit, 33 ... reading unit, 42 ... display unit, 43 ... operation input unit

Claims (8)

A control device,
The minimum gradation value that can be printed in a printing apparatus that prints an image is the minimum gradation value, the maximum gradation value that can be printed in the printing apparatus is the maximum gradation value, and the image having the minimum gradation value is A value corresponding to the target brightness when printing on the printing apparatus is set as the minimum target brightness value, and a value corresponding to the target brightness when printing the image of the maximum gradation value on the printing apparatus is set as the maximum target brightness. First storage control means for preliminarily storing information indicating the minimum target luminance value and the maximum target luminance value in the storage unit of the control device as values;
Based on the measurement result of measuring the brightness of the patch image printed by the printing apparatus, a value corresponding to the brightness when the printing apparatus prints the image of the minimum gradation value is set as the minimum colorimetric brightness value, Based on the measurement result, the minimum colorimetric luminance value and the maximum colorimetric luminance value are set as the maximum colorimetric luminance value corresponding to the luminance when the printing device prints the image of the maximum gradation value. Acquisition means for acquiring the information to be indicated;
A gradation value that is printable in the printing apparatus and that is different from the minimum target luminance value and the maximum target luminance value is a first gradation value, and is printable in the printing apparatus and the minimum target luminance value is A gradation value different from the maximum target luminance value and the first gradation value is set as the second gradation value, and a value corresponding to a target luminance when the printing apparatus prints an image of the first gradation value. Is a first target luminance value, a value corresponding to a target luminance when the image of the second gradation value is printed on the printing apparatus is a second target luminance value, and the minimum colorimetric luminance value and the maximum A difference between the colorimetric luminance value as a colorimetric luminance range, a first colorimetric ratio that is a ratio of the first target luminance value to the colorimetric luminance range, and the second target luminance value relative to the colorimetric luminance range. The first calculation hand that calculates the second colorimetric ratio that is a ratio And,
The difference between the minimum target luminance value and the maximum target luminance value is a target luminance range, the ratio of the first target luminance value to the target luminance range is a first target ratio, and the second target luminance with respect to the target luminance range Correction means for correcting the first colorimetric ratio to be close to the first target ratio by using the ratio of values as the second target ratio, and correcting the second colorimetric ratio to be close to the second target ratio;
The first colorimetric ratio corrected by the correcting unit is set as a first corrected colorimetric ratio, the second colorimetric ratio corrected by the correcting unit is set as a second corrected colorimetric ratio, and the first colorimetric ratio is corrected. The corrected value of one target luminance value is set as a first corrected target luminance value, and the corrected value of the second target luminance value is set as a second corrected target luminance value. The first corrected target luminance value is calculated so that the ratio of the value is the first corrected colorimetric ratio, and the ratio of the second corrected target luminance value to the colorimetric luminance range is the second corrected colorimetric ratio. Second calculating means for calculating the second corrected target luminance value so that
A value corresponding to a target luminance when the printing apparatus prints the first gradation value image is set as the first corrected target luminance value, and the second gradation value image is transferred to the printing apparatus. And a setting unit that sets a value corresponding to a target brightness when printing to the second corrected target brightness value. The correction means includes
When the first colorimetric ratio is not included in a predetermined first correction range including the first target ratio, the first colorimetric ratio is included in the first correction range. To correct the first colorimetric ratio to be close to the first target ratio, and when the second colorimetric ratio is not included in the predetermined second correction range including the second target ratio, 2. The correction for bringing the second colorimetric ratio close to the second target ratio by making the second colorimetric ratio included in the second correction range. Control device. The difference between the minimum gradation value and the first gradation value is smaller than the difference between the maximum gradation value and the first gradation value, and the minimum gradation value and the second gradation value. Is smaller than the difference between the maximum gradation value and the second gradation value, and when the first gradation value is smaller than the second gradation value, the first correction is performed. The control device according to claim 2, wherein the range is narrower than the second correction range. The correction means includes
When the first colorimetry ratio is included in the first correction range, the first colorimetry ratio is set as the first correction colorimetry ratio, and the second colorimetry ratio is included in the second correction range. In this case, the control device according to claim 2 or 3, wherein the second colorimetric ratio is the second corrected colorimetric ratio. 5. The storage device according to claim 1, further comprising: a second storage control unit that stores information indicating the first target luminance value and the second target luminance value in the storage unit in advance. The control device described. The setting means includes
When the maximum colorimetric luminance value is set to a value corresponding to a target luminance when the image of the maximum gradation value is printed on the printing apparatus, and the image of the minimum gradation value is printed on the printing apparatus 6. The control device according to claim 1, wherein a value corresponding to a target luminance is set as the minimum colorimetric luminance value. 7. The storage device according to claim 1, further comprising: a third storage control unit that stores information indicating the first target ratio and the second target ratio in the storage unit in advance. Control device. A computer program for a control device,
In the computer mounted on the control device, the following processing, that is,
The minimum gradation value that can be printed in a printing apparatus that prints an image is the minimum gradation value, the maximum gradation value that can be printed in the printing apparatus is the maximum gradation value, and the image having the minimum gradation value is A value corresponding to the target brightness when printing on the printing apparatus is set as the minimum target brightness value, and a value corresponding to the target brightness when printing the image of the maximum gradation value on the printing apparatus is set as the maximum target brightness. A first storage control process in which information indicating the minimum target luminance value and the maximum target luminance value is stored in advance in the storage unit of the control device as values;
Based on the measurement result of measuring the brightness of the patch image printed by the printing apparatus, a value corresponding to the brightness when the printing apparatus prints the image of the minimum gradation value is set as the minimum colorimetric brightness value, Based on the measurement result, the minimum colorimetric luminance value and the maximum colorimetric luminance value are set as the maximum colorimetric luminance value corresponding to the luminance when the printing device prints the image of the maximum gradation value. An acquisition process for acquiring the indicated information;
A gradation value that is printable in the printing apparatus and that is different from the minimum target luminance value and the maximum target luminance value is a first gradation value, and is printable in the printing apparatus and the minimum target luminance value is A gradation value different from the maximum target luminance value and the first gradation value is set as the second gradation value, and a value corresponding to a target luminance when the printing apparatus prints an image of the first gradation value. Is a first target luminance value, a value corresponding to a target luminance when the image of the second gradation value is printed on the printing apparatus is a second target luminance value, and the minimum colorimetric luminance value and the maximum A difference between the colorimetric luminance value as a colorimetric luminance range, a first colorimetric ratio that is a ratio of the first target luminance value to the colorimetric luminance range, and the second target luminance value relative to the colorimetric luminance range. A first calculation process for calculating a second colorimetric ratio that is a ratio. And,
The difference between the minimum target luminance value and the maximum target luminance value is a target luminance range, the ratio of the first target luminance value to the target luminance range is a first target ratio, and the second target luminance with respect to the target luminance range A correction process for correcting the first colorimetric ratio to be close to the first target ratio, and correcting the second colorimetric ratio to be the second target ratio, with the ratio of the values as the second target ratio;
The first colorimetric ratio corrected by the correction process is set as a first corrected colorimetric ratio, the second colorimetric ratio corrected by the correction process is set as a second corrected colorimetric ratio, and the first colorimetric ratio is corrected. The corrected value of one target luminance value is set as a first corrected target luminance value, and the corrected value of the second target luminance value is set as a second corrected target luminance value. The first corrected target luminance value is calculated so that the ratio of the value is the first corrected colorimetric ratio, and the ratio of the second corrected target luminance value to the colorimetric luminance range is the second corrected colorimetric ratio. A second calculation process for calculating the second correction target luminance value so that
A value corresponding to a target luminance when the printing apparatus prints the first gradation value image is set as the first corrected target luminance value, and the second gradation value image is transferred to the printing apparatus. A computer program for executing a setting process for setting a value corresponding to a target luminance when printing to the second corrected target luminance value.

Images