JP4412470B2 - Improved color matching accuracy under multiple printing conditions - Google Patents

Description

  The present invention relates to an improvement in color matching accuracy when N types of ink droplets having different ink amounts are recorded on a printing medium under a plurality of printing conditions.

In a printing apparatus, even if an image is printed based on the same image data, it is usually possible to perform printing under a plurality of different printing conditions by selecting a resolution or the like. If the printing conditions are different, various conditions such as the amount of ink per ink droplet are different in addition to the above resolution. However, in a printing apparatus, the color of an image printed based on certain image data is always constant. Color matching is required. For this reason, conventionally, color matching is performed by creating a color conversion table for each resolution and selecting the color conversion table according to the resolution at the time of printing (see, for example, Patent Document 1).
JP-A-9-186898

In the above prior art, the required resources tend to increase, and the work of creating a color conversion table for each resolution requires a great effort. More specifically, normally, in the color conversion table, it is necessary to associate output gradation values of the number of ink colors (such as six dimensions) with three-dimensional input gradation values, such as 17 ³ . Define correspondences for many reference points. Therefore, if the data defining the correspondence relations for a large number of reference points is prepared for the number of printing conditions and recorded on the recording medium, the required storage capacity becomes very large.

Further, when the correspondence relationship is defined for the reference points of the color conversion table, it is necessary to actually print a patch with a certain gradation value and measure the color of the printed patch. This color measurement work does not necessarily need to be performed for all 17 ³ reference points, but it is necessary to measure about 10 ³ patches to ensure sufficient color conversion accuracy. There is. Therefore, it takes a great deal of labor to perform the color measurement operation of such a large number of patches as many as the number of printing conditions.

In addition, once a color conversion table is created, a color with low color matching accuracy is readjusted, or when color matching accuracy is reduced due to changes over time in the printing device, calibration is performed to readjust the color. That work was difficult. That is, in the color conversion table, colors are expressed by combinations of color components of each color and the color correspondence is defined, so it is necessary to adjust all the color components of each color at the same time. It has been very difficult to perform color matching by adjusting all the color components of each color at the same time without reducing the color matching accuracy.
The present invention has been made in view of the above problems, and performs high-precision color matching for each printing condition while suppressing required resources, data preparation work necessary for correction, and calibration work. Objective.

  In order to achieve at least one of the above objects, recording amount specifying data is created for each printing condition so that the same color value is obtained even if the printing condition is different if the gradation value is the same. In the present invention, in order to create recording amount specifying data for each printing condition, the correspondence relationship between the gradation value and the color value of the ink color under the reference printing condition is defined in advance in the reference color value data. Further, by printing a patch with a plurality of recording amounts and acquiring the color value, the output color at each recording amount is grasped. If the correspondence relationship between the recording amount and the color value and the correspondence relationship between the gradation value and the color value are found, the recording amount specifying data can be created by associating the recording amount with the gradation value.

  Therefore, in the present invention, the former correspondence is acquired by actually printing a patch under a desired printing condition with a plurality of recording amounts, and the latter correspondence is acquired based on reference color value data prepared in advance. As a result, it is possible to specify an ink droplet recording amount to be output with a desired color value based on an arbitrary gradation value under a desired printing condition. That is, it is possible to create recording amount specifying data for performing color matching under desired printing conditions.

  In the present invention, since the recording amount specifying data is created based on the patch printed under the predetermined printing conditions, the color matching is performed for each printing condition by performing the creation operation of the recording amount specifying data for each printing condition. be able to. As in the above-described prior art, it is also possible to perform color matching for each printing condition by absorbing various differences due to the printing condition by using a color conversion table or the like.

However, the recording amount specifying data in the present invention generally has a very small data capacity compared to the color conversion table. That is, in the recording amount specifying data in the present invention, the gradation value and the recording amount of N types of ink droplets are specified, and N recording amounts are associated with the one-dimensional gradation value. In the color conversion table, generally, a combination of gradation values of about three dimensions is associated with a combination of gradation values of six dimensions or more. More specifically, in the color conversion table it is necessary to define the correspondence between the number of reference points such as 17 ^three.

  On the other hand, in the recording amount specifying data that associates the gradation values with the recording amounts of N types of ink droplets, about 33 reference points are specified for the gradation values, and N types of ink droplets are set for each reference point. It is sufficient if the amount of recording can be defined. Accordingly, the recording amount specifying data is overwhelmingly smaller in capacity than the color conversion table. For this reason, it is possible to perform color matching with high accuracy while greatly reducing required resources. Further, in the configuration in which color matching is performed for each of a plurality of printing conditions as in the present invention, it is necessary to prepare the recording amount specific data capacity as many as the number of printing conditions. The effect of suppressing the capacity is more conspicuous than

  Further, the present invention is very efficient in data creation work. That is, in the patch printed when creating the recording amount specifying data, it is sufficient that the one-dimensional gradation value and the color value can be associated with each other. However, in the patch printed when creating the color conversion table, It is necessary to associate an output color and a color value by a combination of multi-dimensional gradation values. Therefore, in the same gradation value range, the former requires a very small number of patches compared to the latter, and the burden of data creation work is remarkably small. Furthermore, even if the calibration work is performed to verify the accuracy of the conversion accuracy in the recording amount specifying data once created or to adjust the content of the recording amount specifying data after a change with time in the printing apparatus, the recording amount Since the specific data has a smaller amount of information, calibration can be performed with less work.

  Here, the plurality of printing conditions may be printing conditions in which the recording amount of N types of ink droplets, the ink amount per unit ink droplet, and the like may vary depending on the printing conditions. In addition, if the conditions are such that the output colors differ when printing is performed with the same recording amount under different conditions, it can be said that the printing conditions in the present invention are satisfied. As the printing condition, for example, the resolution in the printing apparatus can be adopted. That is, since the degree of definition of the required image varies with different resolutions, the ink amount per unit ink droplet is changed for each resolution.

  Therefore, color matching cannot be performed for each resolution unless the correspondence between the gradation value for each ink color and the recording amount of N types of ink droplets is changed for each resolution. Therefore, by creating the recording amount specifying data for each printing condition according to the present invention, it is possible to perform color matching for each printing condition. Of course, the printing conditions are not limited to the resolution, but the type of ink supported by each printer (dye type, pigment type, etc.), the type of media (type of paper, whether CD labels can be printed, etc.) Various conditions can be adopted.

  Various configurations can be adopted as a configuration for recording N types of ink droplets on the print medium. That is, here, it is only necessary that the size of the ink droplet (the amount of the ink droplet) is variable and pixels having different sizes can be formed on the print medium. For this reason, N may be 2 or more, but since the gradation of one pixel can be expressed by 2 bits, a configuration using three types of ink droplets is often used.

In the reference color value data, it is only necessary to associate the tone value and the color value for each ink color. Here, the gradation value for each ink color is a value that indicates stepwise changes in density, lightness, etc., for each ink color used in the printing apparatus. Further, the color value may be a value indicating the output color at each gradation value, and can be expressed using coordinate values in a device-independent color space such as L ^* a ^* b ^* . Although it is most accurate to use all of the color components forming the color space when expressing the color values, a part of the color components is simply used to indicate the output color at each gradation value. Anyway. Of course, in this case, the output color may be expressed using different color components for each ink color.

  The patch printing unit only needs to be able to print a patch under predetermined printing conditions so as to record each ink droplet with a plurality of target recording amounts. That is, it is only necessary to be able to print a patch for measuring the color recorded at each recording amount. For this reason, it is preferable to select a plurality of target recording amounts so as to cover colors corresponding to the entire range of gradation values for each ink color. Of course, since any one or a combination of each of the N types of ink droplets is recorded for one gradation value, the recording amount is specified for all of the N types of ink droplets with one target recording amount.

  The color value data acquisition means only needs to be able to acquire color value data indicating the color value of the patch. Therefore, it is possible to adopt a configuration in which a printed patch is color-measured by a predetermined colorimeter and data indicating the color measurement result is acquired by a predetermined interface or acquired via a predetermined recording medium.

  If the recording amount specifying data creating means can create the recording amount specifying data by referring to the color value data and the reference color value data and associating the recording amount of each of the N types of ink droplets with the target gradation value. Good. That is, the color value data reveals the correspondence between the recording amount of each of the N types of ink droplets and the color value obtained by printing under the predetermined printing conditions with the recording amount. Further, according to the reference color value data, the color value to be associated with each gradation value is found. Therefore, recording amount specifying data is created from the correspondence between the two.

  Furthermore, in the reference color value data, it is sufficient that at least the gradation value for each ink color and the color value are associated with each other. Color value data may be constructed. For example, it may be constituted by data including reference color conversion table data and reference recording amount specifying data. That is, in a printing apparatus capable of recording N types of ink droplets, the input gradation value is color-converted with reference to the color conversion table, and the gradation value after color conversion is converted into the ink droplet with reference to the recording amount specifying data. In many cases, a configuration is employed in which printing is performed by converting the recording amount to each recording amount.

  At this time, the input gradation value is converted by the reference color conversion table data and the reference recording amount specifying data, and a patch based on the recording amount obtained by the conversion is printed under reference printing conditions. Adjustment is made in advance so as to match the color value corresponding to the input gradation value. Therefore, by referring to the reference color conversion table data and the reference recording amount specifying data, it is possible to easily grasp the correspondence between the gradation value and the color value for each ink color. In color matching in a printing apparatus, it is well known to create a set of reference color conversion table data and reference recording amount specifying data.

  However, in the present invention, it is only necessary to create a set of the reference data under a predetermined printing condition, and for other printing conditions, color matching is performed by creating recording amount specifying data for each printing condition. Therefore, in order to perform color matching, it is necessary to create one set of reference color conversion table data and reference recording amount specifying data, but it is not necessary because a color conversion table is not created for each printing condition. High-accuracy color matching can be performed for each printing condition while suppressing resources, data preparation work necessary for correction, and calibration work. As the input gradation value, it suffices if the color can be uniquely specified by the gradation value, and various color systems such as coordinate values of the device-independent color space and color component values of the sRGB standard are adopted. Is possible.

  Here, as a specific example of the reference recording amount specifying data, it is possible to adopt a configuration that prescribes a correspondence relationship between the gradation value for each ink color and the recording amount of each ink droplet in common for all the ink colors. It is. That is, referring to the reference color conversion table data and the reference recording amount specifying data, the input gradation value is converted into the ink recording amount, and the reference recording amount specifying data is common to each color when printing is performed. Color matching can be performed by adjustment using conversion table data.

  Specifically, recording amount specifying data common to all ink colors is created, and the tone value of each ink color is converted with this data, and the color value of the output color is measured. Since the color value to be associated with the input gradation value is known in advance, if the measured color value is used, the reference gradation conversion table data is obtained by associating the input gradation value with the gradation value for each ink color. Can be created. That is, color matching can be performed even if the common recording amount specifying data is used for all the ink colors by associating the input gradation value with the gradation value for each ink color by performing a color measurement operation. it can. If the recording amount specifying data common to all the ink colors is used, it is not necessary to create recording amount specifying data for each ink color, so that necessary resources and the creation work process can be suppressed.

  Further, as a specific example of the recording amount specifying data generating means, a configuration in which the recording amount specifying data is individually generated for each ink color can be adopted. That is, the recording amount of ink droplets with respect to the gradation value for each ink color can be different for each color. Therefore, by creating recording amount specifying data for each color, it is possible to perform color matching with high accuracy. In the present invention, color matching for each printing condition is performed by creating recording amount specifying data for each printing condition. Therefore, if the color matching can be performed with higher accuracy by changing the recording amount specifying data at least for each printing condition than when printing with a common recording amount for each printing condition, a common recording for each ink color is possible. A configuration for creating the quantity specifying data can also be adopted.

  Further, as a preferred configuration of the patch printing unit, a configuration of preparing recording amount specifying temporary data indicating a temporary correspondence relationship between the gradation value and the recording amount of each of the N types of ink droplets can be employed. That is, if a plurality of target gradation values are specified by the recording amount specifying temporary data indicating the provisional correspondence, the recording according to the present invention can be performed only by performing adjustment based on the recording amount specifying temporary data in the recording amount specifying data creating means. Quantity specific data can be created.

  As a configuration suitable as the recording amount specifying temporary data, it is possible to adopt a configuration in which a plurality of printing conditions are created in advance in consideration of the ink amount per unit ink droplet for each of a plurality of printing conditions. That is, the color value corresponding to the recording amount is not known unless printing is performed for each printing condition and colorimetry is performed, but the ink amount per unit ink droplet can be determined in advance for each printing condition. Therefore, the recording amount specifying temporary data is created for each printing condition, and at this time, the ink amount per unit ink droplet is made different for each printing condition.

  For example, when creating a recording amount specifying temporary data in a printing apparatus that records three types of large, medium, and small ink droplets, only the large ink droplet recording amount is associated with the gradation value for each ink color, and then the total amount of ink droplets is calculated. Part or all of the large ink droplets are distributed to small and medium dots so that the recording amount does not change. Even if the recording amount specifying temporary data is created according to such a rule, if the ink amount per unit ink droplet is different due to the different printing resolution as the printing condition, the recording amount specifying temporary data is also different for each printing condition. . Therefore, by using the recording amount specifying temporary data in consideration of the ink amount per unit ink droplet, it is possible to create the recording amount specifying data by reliably reflecting the matters to be changed for each printing condition.

  Furthermore, the recording amount specifying data creating means can easily create the recording amount specifying data for each printing condition by using the recording amount specifying temporary data. That is, referring to the recording amount specifying temporary data and the color value of the patch, the temporary ink recording amount is calculated based on the correspondence between the gradation value defined in the recording amount specifying temporary data and the temporary ink recording amount. The color value of the color to be printed can be grasped. Further, by referring to the reference recording amount specifying data, it is possible to grasp the color value of the color to be printed with the target gradation value.

  Accordingly, when a temporary ink recording amount for outputting the color value of the color to be printed at the target gradation value is calculated, and the gradation value and the temporary ink recording amount are associated with each other, the target gradation is obtained under each printing condition. The tone value is associated with the ink recording amount for outputting the color value to be printed with the gradation value. Thereby, the recording amount specifying data can be easily created. Since the recording amount specifying data is based on the color value obtained by printing the patch according to the actual printing conditions, accurate color matching can be performed for each printing condition.

  The recording amount specifying data may be data that associates the ink droplet recording amount with the target gradation value, and can be composed of data in which the ink droplet recording amount is associated with a plurality of target gradation values. It is. Various ideas can be made when selecting the target gradation value. For example, in a configuration using the reference color conversion table data, a plurality of gradation values are stored as gradation values for each ink color in the reference color conversion table data, and the stored gradation values are equal. It may not be an interval. In this case, a specific value range in which the gradation values stored in the reference color conversion table data are distributed more than other value ranges is extracted, and more gradation values included in this value range are selected than the other value ranges to select the target scale. Use the key value.

  In other words, the gradation values stored in the reference color conversion table data are not evenly selected and are biased depending on the range of values. This means that the bias has better color conversion accuracy and rich gradation expression. There are some advantages, such as being possible. Therefore, by selecting the target gradation value with the same tendency as the reference color conversion table data as the recording amount specifying data, it is possible to maintain the same advantages as those described above.

  The above configuration is a recording amount specifying data creating apparatus for performing color matching with high accuracy for each printing condition in a printing apparatus capable of recording N types of ink droplets. The invention is also established. Therefore, the invention according to claim 10 basically has the same action as described above. Also, the present invention can be applied as a program for implementing the present invention, and the invention according to claim 11 basically has the same operation as described above.

  Of course, it is also possible to make the structure described in claims 2 to 9 correspond to the above method and program. Any storage medium can be used to provide the program. For example, a magnetic recording medium or a magneto-optical recording medium may be used, and any recording medium that will be developed in the future can be considered in the same manner. In addition, even when a part is software and a part is realized by hardware, the idea of the present invention is not completely different, and a part is recorded on a recording medium and is appropriately changed as necessary. It includes a reading form.

Furthermore, in the present invention, since the recording amount specifying data capable of performing color matching with high accuracy is created for each printing condition, the recording amount of each of the N types of ink droplets is determined by referring to the recording amount specifying data after the creation. Even the printing control apparatus, method, and program to be determined can use the technical idea according to the present invention .

Here, embodiments of the present invention will be described in the following order.
(1) Outline of the present invention:
(2) Configuration of large / small / small distribution table creation device:
(2-1) Structure of large / small / small allocation temporary table:
(2-2) Creation process of large / small / small distribution table:
(3) Other embodiments:

(1) Outline of the present invention:
FIG. 1 is an explanatory diagram schematically illustrating a mechanism for performing color matching with high accuracy in the large, medium, and small sorting table according to the present invention. In the figure, the manner in which the color system and the data format are converted during the printing process is schematically shown. A rectangle with characters on the upper right indicates image data composed of pixels in a dot matrix. RGB is red, green, blue, and CMYKlclm is cyan, magenta, yellow, black, light cyan, and light magenta, respectively. Further, large, medium and small attached to the rectangle shown on the right side of the figure indicate the size of the ink droplet. That is, the printer according to the present invention can eject ink droplets with three different ink amounts, and can express four gradations per pixel. In this specification, paying attention to the size of ink droplets, each ink droplet is distinguished as large, medium and small.

  In the figure, in printing, RGB image data is converted into CMYKlclm tone value data, and further converted into recording amount data indicating recording amounts of large, medium, and small dots for each color of CMYKlclm. Here, the RGB image data is image data indicating an image to be printed, and is composed of, for example, gradation data of 256 gradations for each color of RGB. The CMYKlclm gradation value data is gradation data for each ink color used in the printer, and is composed of, for example, gradation data of 256 gradations for each color.

  Of course, in FIG. 1, the color components constituting the image data and the gradation value data are not limited to RGB and CMYKlclm. The CMYKlclm recording amount data is data defining the recording amount for each large, medium, and small dot for each color of CMYKlclm, and is composed of, for example, gradation data of 256 gradations for each dot. Both the CMYKlclm gradation value data and the CMYKlclm recording amount data can be expressed by gradation data. However, in this specification, the latter is expressed as a recording amount.

Conversion from RGB image data to CMYKlclm gradation value data is performed by a color conversion table (LUT). LUT includes a plurality of reference points (e.g., 17 ³⁾ is associating data and combinations of the combination and CMYKlclm tone values of RGB gradation values per. Thus, the correspondence relationship is defined for any combination of gradation values in both color systems, and any RGB image data can be converted into CMYKlclm gradation value data by interpolation calculation.

  Conversion from the CMYKlclm gradation value data to the CMYKlclm recording amount data is performed by the large / medium / small distribution table. The large / medium / small distribution table is data in which recording amounts of large / medium / small dots are associated with a plurality of gradation values (for example, 33). Accordingly, the correspondence between the arbitrary gradation value and the recording amount of large, medium, and small dots is defined, and the arbitrary CMYKlclm gradation value can be converted into the recording amount of large, medium, and small dots by interpolation calculation.

  When printing with a printer, printing is performed by specifying various printing conditions such as resolution at the time of printing, and the amount per droplet of large, medium, and small dots varies depending on the printing conditions. The setting fluctuates. Therefore, if printing is performed using a common LUT and large / medium / small distribution table for each printing condition, color matching cannot be performed under all printing conditions. Therefore, usually, data is created for each printing condition.

  That is, the LUT is usually used to convert RGB color system data into CMYKlclm color system data while performing color matching. The large / medium / small distribution table is normally used to simply distribute CMYKlclm gradation values to large / medium / small dots. Therefore, conventionally, an LUT is created so that color matching is performed when printing is performed according to a large, medium, and small sorting rule determined in advance for each printing condition. However, in the present invention, a common LUT is used for a plurality of printing conditions, and color matching for each printing condition is performed by creating different large, medium, and small distribution tables for each printing condition.

More specifically, an LUT and a large, medium, and small distribution table are created so that color matching is performed under the standard printing conditions (resolution 1 in FIG. 1), and under different printing conditions (resolution 2 and resolution 3 in FIG. 1). The LUT is diverted and the large, medium, and small sorting tables are adjusted so that color matching is performed. When creating an LUT, the above reference points are obtained from the correspondence between the colorimetric values of patches printed by a combination of a plurality of (for example, about 10 ³ ) CMYKlclm tone values and the color values corresponding to RGB image data. It is defined so that the colors associated with each other match.

  In printing this patch, the CMYKlclm tone value is converted into a recording amount of large, medium, and small dots with reference to a large, medium, and small distribution table created according to a large, medium, and small distribution rule that is determined in advance for the standard printing condition. For example, in each of the large, medium, and small dots, this rule is defined such that the ink recording amount increases according to a specific rule as the gradation value increases, or the brightness of the output color is a specific rule as the gradation value increases. Various rules can be adopted, such as defining the number to increase at

  Whatever the rule, once the large, medium, and small distribution table is determined, the recording amount of large, medium, and small dots for each gradation value is specified under the standard printing conditions. The color is determined uniquely. Therefore, as described above, an LUT is created from the correspondence between the colorimetric value of the patch and the color value of the RGB image data. That is, under the standard printing conditions, CMYKlclm gradation values that output a color equivalent to the color that the RGB image data means in the LUT are extracted and correlated. As a result, color matching is performed.

  On the other hand, in the printing conditions different from the standard printing conditions, the large, medium, and small sorting tables obtained by following the above-described large, medium, and small sorting rules are different. For example, if the setting varies depending on the printing conditions, such as the amount of ejection per large, medium, and small dots fluctuating, the results obtained may be different even if the same large, medium, and small sorting rules are used. However, since the large, medium, and small sorting rules are not rules for performing color matching, even if a large, medium, and small sorting table that differs for each printing condition is created according to the large, medium, and small sorting rules, color matching is not performed by itself.

  Therefore, conventionally, an LUT is created for each printing condition. However, in the present invention, color matching is performed by adjusting a large / medium / small distribution table for each printing condition as described later. As a result, according to the present invention, high-precision color matching can be realized with less resources. Further, it is possible to reduce the burden of data creation work and correction work for color matching.

FIG. 2 is an exemplary diagram for explaining a difference in resources between a configuration for creating an LUT for each printing condition and a configuration for adjusting a large / medium / small distribution table for each printing condition. In the example shown in the figure, LUT is associated for the RGB image data and the CMYKlclm gradation value 17 ³ reference point, a volume of about 40KB. In the large / medium / small distribution table, 33 gradation values are associated with the recording amounts of large, medium, and small dots.

  In the large / medium / small distribution table, there may be a case where a common recording amount may be sufficient for each color of CMYKlclm, or a recording amount adjusted for each color of CMYKlclm. That is, when color matching is performed by LUT, a common medium / medium / small distribution table may be used for each color of CMYKlclm, and when color matching is performed using the large / medium / small distribution table, adjustment is required for each color of CMYKlclm. In the example shown in FIG. 2, the former is about 4 KB and the latter is about 22 KB.

  In FIG. 2, the conventional LUT and large / medium / small distribution table are shown in the upper part, and the LUT and large / medium / small distribution table according to the present invention are shown in the lower part. That is, conventionally, color matching is performed by adjusting the reference points stored in the LUT, and therefore a separate LUT is required for each printing condition. In this case, since color matching is performed by the LUT, the large / medium / small distribution table may be common to all colors. Therefore, when the printing conditions are resolution 1 to resolution 3, a storage capacity of 132 KB in total, that is, three 40 KB LUTs and three 4 KB large / medium / small distribution tables.

  However, in the present invention, color matching is performed only with the resolution 1 using the LUT, and the color matching is performed with the large, medium, and small distribution tables for the resolutions 2 and 3 while using the LUT with the resolution 1. Therefore, one 40KB LUT, one 4KB large / medium / small distribution table, and two 22KB large / medium / small distribution tables, which have a total storage capacity of 88KB, can reduce the required resources. .

Further, the creation of these data is less in the present invention, and the data can be easily prepared. That is, when creating the LUT, it is necessary to print about 10 ³ patches. However, since the gradation values specified in the large, medium, and small distribution table are about 33, printing is necessary for adjustment. There are about 33 patches. Therefore, although the creation work effort for resolution 1 is the same between the conventional and the present invention, the work effort for resolution 2 and resolution 3 is significantly smaller in the present invention. Furthermore, the effort of the present invention is significantly smaller when readjusting the LUT and the large / medium / small distribution table. That is, even when the patch is reprinted at the time of readjustment, the work effort is small and the readjustment can be easily performed.

(2) Configuration of large / small / small distribution table creation device:
FIG. 3 is a block diagram showing a configuration example of the large / medium / small distribution table creation device. In the embodiment shown in the figure, by starting application software (APL) 110 for creating a large, medium, and small distribution table on the computer 100, the computer 100 is caused to function as a large, medium, and small distribution table creation device. In FIG. 3, the computer 100 includes a user interface such as a display and a keyboard, and a storage device such as a hard disk drive (HDD) 120. In addition, a program execution environment such as a CPU, a RAM, and a ROM is provided, and the APL 110 can be executed by these devices under control of an operating system (not shown).

  A printer 200 is connected to the computer 100 via the USB I / F 130. The printer 200 can be equipped with a tank filled with six colors of CMYKlclm, and is an inkjet printer that records images by ejecting large, medium, and small ink droplets for each color. The printer 200 can execute printing at a plurality of default resolutions (resolution 1 to resolution 3), and can execute printing while changing the amount of large, medium, and small dots per dot drop for each resolution. Yes.

A colorimeter 300 can be further connected to the computer 100. The colorimeter 300 can detect the spectral reflectance of the printed material by irradiating the printed material with a known light source and detecting reflected light, and output the color value, for example, the L ^* a ^* b ^* value or the XYZ value. is there. Data indicating the color value is transferred to the computer 100 via the USB I / F 130.

  The APL 110 includes a patch printing unit 112, a color value acquisition unit 114, and a large / medium / small distribution table creating unit 116. Refer to the reference data 122 and the large / small / small distribution temporary tables 124a and 124b recorded in the HDD 120. The large, medium and small distribution tables 126a and 126b are created. The reference data 122 includes a reference LUT 122b that can perform color matching at a reference resolution (resolution 1) and a large / medium / small distribution table 122a.

(2-1) Structure of large / small / small allocation temporary table:
The large / medium / small distribution table 122a and the large / medium / small distribution temporary tables 124a and 124b are table data created according to the large / medium / small distribution rule as described above. In the present embodiment, the weight ratio of large / medium / small dots is set. A distribution rule is defined and created based on this. FIG. 4 is an explanatory diagram for explaining the distribution rule of the large, medium, and small dots. In the figure, the horizontal axis indicates CMYKlclm gradation values, and the vertical axis indicates the ink recording amount. The ink recording amount for small dots is indicated by a solid line, the ink recording amount for medium dots is indicated by a one-dot chain line, and the ink recording amount for large dots is indicated by a two-dot chain line.

  When performing large, medium, and small distribution, first, the correlation between the gradation value and the ink recording amount is determined for only large dots. In FIG. 4, as indicated by the broken line, when the gradation value increases linearly from 0 to 255, the gradation value indicating the ink recording amount increases linearly from 0 to 255. In this embodiment, based on this premise, the large dots are replaced with small dots and medium dots in terms of equal weight. That is, when the weight ratio of large dots to small dots is aXs: a, the large dot amount a is replaced with the small dot amount aXs. When the weight ratio of large dots to medium dots is bXm: b, the large dot amount b is replaced with the medium dot amount bXm.

  In the example shown in FIG. 4, the correlation of only the large dots indicated by the broken line is a straight line with a slope of 1, and all the large dots are small until the gradation value s where the ink recording amount of the gradation value 0 to the small dot is maximum. Sorted into dots. Therefore, in the gradation value 0 to the gradation value s, the small dot becomes a straight line having an inclination Xs as shown by the solid line. In addition, the gradient of small dots is set to −Xs from the gradation value s to the gradation value m where the ink recording amount of the medium dot is maximum. When substituting with small dots in this way, the ink recording amount of large dots from gradation value 0 to gradation value s becomes 0, and the ink recording amount indicated by the double line in gradation values s to m. .

  In FIG. 4, the ink recording amount of only large dots indicated by double lines in the gradation values s to m is replaced with medium dot ink. As a result, a straight line as indicated by a one-dot chain line having an inclination of Xm times the inclination of the double line is the medium dot recording amount. In the gradation values m to 255, the ink recording amount of medium dots is set to an ink recording amount that linearly changes from the maximum value to 0, and the remaining is set to the ink recording amount of large dots as indicated by a two-dot difference line. The above distribution rule is an example, and of course, the specific values of the gradation value s and the gradation value m are not limited, and the change tendency of large, medium, and small dots is not limited to a linear change, You may comprise so that a recording amount may not change in a certain gradation value range. Further, a constraint condition may be imposed such that the recording amount of each ink does not exceed a predetermined value.

  In the present embodiment, the weight ratio of large, medium and small dots is changed for each resolution. In other words, since the definition required for an image varies depending on the resolution, the weight of large, medium, and small dots becomes lighter as the definition becomes higher. Therefore, as shown in FIG. 4, when the gradation value increases linearly from 0 to 255, the gradation value indicating the ink recording amount of large dots increases linearly from 0 to 255. Even if sorting is performed, the large, medium and small sorting tables obtained are different.

  FIG. 5 is an explanatory diagram showing how the allocation table differs for each resolution. In the present embodiment, the same rule applies to the recording amount of large dots that change linearly with respect to the gradation values 0 to 255 for each resolution. Replace with small dots and medium dots. The distribution table shown in the upper right part of the figure is a table for resolution 1, and the weight ratio of dots is large: medium: small = 1: 0.43: 0.21. The distribution table shown in the middle right part of the figure is a table for resolution 2, and the weight ratio of dots is large: medium: small = 1: 0.5: 0.21. The distribution table shown in the lower right of the figure is a table for resolution 3, and the weight ratio of dots is large: medium: small = 1: 0.67: 0.33.

  As a result, there are various differences such as resolution 1 = resolution 2> resolution 3 when comparing the maximum recording amount of small dots, and resolution 1> resolution 2> resolution 3 when comparing the maximum recording amount of medium dots. The above-mentioned large / medium / small distribution table 122a is a table created for resolution 1, and the large / medium / small distribution temporary tables 124a and 124b are tables created for resolution 2 and resolution 3, respectively.

  In the present embodiment, the large / medium / small distribution table 122a and the large / medium / small distribution temporary tables 124a and 124b do not distinguish the color gradation values of CMYKlclm for each color, and the gradation value and the large / medium / small dot recording amount. This data defines the correspondence between However, in the large / medium / small distribution table 122a, color matching is performed by referring to the reference LUT 122b as a set. That is, the color of the patch printed at resolution 1 is measured, and the reference LUT 122b is created by associating the colorimetric value with the color value indicated by the RGB image data. Therefore, color matching is performed even if the large, medium, and small distribution table 122a is common to all colors.

  On the other hand, the large, medium, and small distribution temporary tables 124a and 124b are referred to, and the color matching is performed by creating the large, medium, and small distribution tables 126a and 126b by processing by the APL 110. In this sense, the large, medium, and small distribution temporary tables 124a and 124b are named “temporary”. Note that RGB image data corresponding to an arbitrary gradation value can be calculated by referring to the reference LUT 122b and the large / medium / small distribution table 122, so that a color value corresponding to an arbitrary gradation value is calculated. be able to.

More specifically, if RGB image data is sRGB standard data, the color value can be calculated from the RGB gradation value. In the present invention, the correspondence relationship between the gradation value and the color value is acquired by the large / medium / small distribution table creating unit 116 as will be described later. However, the reference for acquiring the correspondence relationship between the gradation value and the color value is used. Of course, the LUT 122b is not limited to the above-described mode, and a profile in which CMYKlclm gradation values and color values (L ^* a ^* b ^*, etc.) are associated with each other like an ICC profile may be adopted.

(2-2) Creation process of large / small / small distribution table:
Next, based on FIG. 6 and FIG. 3, the process of creating the large, medium, and small distribution tables 126a and 126b in the APL 110 with reference to the reference data 122 and the large, medium, and small distribution temporary tables 124a and 124b will be described. FIG. 6 is a processing flow by the APL 110. In step S100, printing conditions are set via the user interface such as the keyboard. That is, the printing conditions when the created large, medium, and small distribution table is used are designated. In the present embodiment, either resolution 2 or resolution 3 is set.

  The patch printing unit 112 is a module for generating and printing patch data to be measured. In step S105, the patch printing unit 112 extracts / acquires data corresponding to the set printing conditions from the large / medium / small distribution temporary tables 124a and 124b. Since the data specifies the recording amount of large, medium and small dots for 33 gradations out of 256 gradations, a predetermined patch is printed at each recording amount corresponding to the 33 gradation values. Print data is created, and printing is performed in step S110.

  Here, one of CMYKlclm is set as a target color to be processed, print data for printing a patch for the target color is created, and output to the USB I / F 130. As a result, the printer 200 prints 33 patches for the target color. The color value of the printed patch is captured by the color value acquisition unit 114. That is, the printed patch is measured by the colorimeter 300, and data indicating the color value is input to the computer 100 via the USB I / F 130. Then, the color value acquisition unit 114 acquires data indicating the color value in step S115.

  In step S120, the colorimetric correspondence acquisition unit 116b of the large / medium / small distribution table creation unit 116 acquires the correspondence between the gradation value and the color value printed by each gradation value. That is, the plurality of gradation values acquired by the patch printing unit 112 and the color values acquired by the color value acquisition unit 114 are passed to the colorimetric correspondence acquisition unit 116b, and are associated with each other. Of course, the color value acquisition unit 114 acquires data so as to know in advance which color value is the color value obtained by measuring the print result for which gradation value. As described above, a correspondence relationship between a plurality of gradation values and color values can be acquired. In this embodiment, fitting is performed using a predetermined multi-order function so that a color value for an arbitrary gradation value can be calculated. .

FIG. 7 shows this state. This figure shows a state where output colorimetric values for specific ink colors are plotted in a L ^* a ^* b ^* space with black circles. Of course, each black circle is associated with a gradation value defined in the large, medium, and small allocation temporary table. Since the color values obtained by colorimetry like the black circles shown in the figure are discrete values, a predetermined multi-order function is defined. For example, a quadratic or higher function that gives an L ^* value using a gradation value as a variable, a secondary or higher function that gives an a ^* value using a gradation value as a variable, and a b ^* value using a gradation value as a variable. A function can be calculated by defining a function of second order or higher and calculating each coefficient.

  Thereby, a color value is obtained when printing is performed for an arbitrary gradation value under the printing conditions set in step S100. In FIG. 7, the locus of the function (plotted color values for arbitrary gradation values) is shown by a solid line. In this specification, the correspondence between the gradation value and the color value indicated by the solid line is referred to as a colorimetric correspondence. Since the large, medium, and small allocation temporary tables 124a and 124b determine the recording amount of large, medium, and small dots that are associated with each gradation value, the color value and the recording amount of large, medium, and small dots are associated with each other. I can also say.

  Next, in the large / medium / small distribution table creation unit 116, processing by the reference correspondence acquisition unit 116a is performed. The reference correspondence acquisition unit 116a is a module that acquires the correspondence between the gradation value and the color value at the reference resolution 1, and in the present embodiment, acquires the reference LUT 122b in step S125. In step S130, the reference LUT 122b is referred to, and a color value for an arbitrary gradation value of the target color is acquired.

  That is, with reference to the reference LUT 122b, corresponding RGB image data for any combination of CMYKlclm can be calculated, and thereby the color value can be obtained. Therefore, by setting the gradation values other than the target color to 0 and changing the target gradation value from 0 to 255 and acquiring the corresponding color value, the color value for an arbitrary gradation value can be acquired. In FIG. 7, a color value for an arbitrary gradation value is indicated by a broken line. In this specification, the correspondence indicated by the broken line is referred to as a reference correspondence.

  The reference correspondence relationship indicates a color value to be output at each CMYKlclm tone value. Therefore, in the present invention, even when printing is performed by performing conversion using the large, medium, and small distribution tables 126a and 126b corresponding to the resolution 2 and the resolution 3, the color values indicated in the reference correspondence relationship at each gradation value can be obtained. The large, medium, and small distribution tables 126a and 126b may be created so that For this purpose, the recording amount gradation value correspondence unit 116c refers to the reference correspondence relationship and the colorimetric correspondence relationship, and sets the recording amount of large, medium, and small dots for a plurality of target gradation values in steps S135 to S150. Perform the process of associating.

In the lower part of FIG. 7, a part of the L ^* a ^* b ^* space is enlarged and an example of this processing is shown. In step S135, to isolate the target tone value T _1, the color value corresponding to the target tone value T ₁ by referring to the reference relationship (Lab in FIG 7 (T ₁₎₎ to obtain a. Next, in step S140, the colorimetric correspondence is referred to, and the gradation value T ₂ corresponding to the substantially same color value (Lab (T ₂ ) in FIG. 7) as the acquired color value is acquired.

In FIG. 7, when the broken line indicating the reference correspondence and the solid line indicating the colorimetric correspondence intersect, the color value Lab (T ₁ ) and the color value Lab (T ₂ ) have the same color value. On the other hand, if they do not intersect, the color value Lab (T ₁ ) and the color value Lab (T ₂ ) having the minimum color difference ΔE _min are selected from the color values indicating the colorimetric correspondence. As a result of the above processing, the tone value T ₂ required to output substantially the same color as the color indicated by the target tone value T ₁ in the large, medium, and small allocation temporary table acquired in step S105 has been found. become.

Therefore, in step S145, with reference to the large, medium and small sorting temporary table acquired at step S105, it acquires the recording amount of large, medium and small dot corresponding to the tone value T _2. Recording the amount of the large, medium and small dots for a record amount for outputting the substantially same color as the color indicated by the target tone value T _1, the recording of step S150 the large, medium and small dots and the target tone value T ₁ Associate.

One target tone value T ₁ and the correspondence between the recording of the large, medium and small dots is finished, the processing for all the target to be stored, it is determined whether or not finished at step S155 as large, medium and small sorting table. If it is not determined in step S155 that the processing has been completed for all the targets, unprocessed gradation values are adopted as new targets in step S160, and step S135 and subsequent steps are repeated. As a result, a table in which a plurality of gradation values are associated with the recording amounts of large, medium, and small dots for the target color is created.

  In step S165, it is determined whether or not processing has been completed for all colors CMYKlclm as target colors. If it is not determined that processing has been completed for all colors, unprocessed colors are set as target colors in step S170. The processes after S110 are repeated. If it is determined in step S165 that the processing has been completed for all colors, the obtained data is stored in the large / medium / small distribution table 126a or 126b and recorded in the HDD 120 in step S175. That is, data in which a plurality of target gradation values and recording amounts of large, medium, and small dots are associated with each color is recorded as a large, medium, and small distribution table.

  By performing the above processing for each printing condition, the large, medium, and small sorting tables 126a and 126b that perform color matching under each printing condition while diverting the reference LUT 122b that performs color matching under the reference printing condition (resolution 1). Can be created. In the present invention, it is sufficient if a large, medium, and small distribution table can be created so that color matching can be performed for each printing condition, and a processing procedure different from that in FIG. For example, the order of processing by the reference correspondence acquisition unit 116a and processing by the colorimetric correspondence acquisition unit 116b may be reversed.

(3) Other embodiments:
The large / medium / small distribution table 126a, 126b, the reference LUT 122b, and the large / medium / small distribution table 122a created as described above are used in a printing process performed on a general-purpose computer. FIG. 8 is a block diagram illustrating a computer configuration example that uses the large, medium, and small distribution tables 126a and 126b and the like during printing. The computer 101 is a general-purpose personal computer, and a printer driver (PRTDRV) 165, an input device driver (DRV) 162, and a display driver (DRV) 161 are incorporated in the OS 160. The display DRV 161 is a driver that controls display of image data and the like on the display, and the input device DRV 162 receives a code signal from the keyboard or mouse input via the serial communication I / F 190a and performs a predetermined input operation. It is a driver to accept.

  The APL 170 is an application program that can execute retouching of a color image, and the user can operate the input device for operation under the execution of the APL 170 and cause the printer 200 to print the color image. The printer 200 is the same model as the printer shown in FIG. The large, medium, and small distribution table created by the present invention at the time of printing such a color image is referred to. The image data 150 a of the color image created by the APL 170 is dot matrix data representing each RGB color component in gradation, and is recorded on the HDD 150. Here, the image data 150a is data compliant with the sRGB standard.

  In order to execute printing, the PRTDRV 165 includes an image data acquisition module 165a, a color conversion module 165b, a large / medium / small distribution module 165c, a halftone processing module 165d, and a print data generation module 165e. When the user sets a desired printing condition (any one of resolution 1 to resolution 3 in the example shown in FIG. 8) and issues a print execution instruction when executing APL 170, image data 150a indicating an image to be printed becomes image data. Acquired by the acquisition module 165a, the image data acquisition module 165a activates the color conversion module 165b. The color conversion module 165b is a module that converts sRGB gradation values into CMYKlclm gradation values. The color conversion module 165b refers to the reference LUT 122b and converts the sRGB gradation values into CMYKlclm gradation values by interpolation.

  The large / medium / small distribution module 165c converts the data indicating the recording amount of large / medium / small dots for each color based on the CMYKlclm gradation value after color conversion. That is, data that matches the printing conditions set in the print execution instruction is selected from the large, medium, and small distribution modules 122a, 126a, and 126b. This large / medium / small distribution module associates CMYKlclm gradation values with gradation values indicating the recording amounts of the large, medium, and small dots with respect to a plurality of reference values. Therefore, the CMYKlclm performs interpolation calculation as necessary. The recording amount of large, medium and small dots corresponding to the gradation value is acquired.

  When the recording amount of large, medium, and small dots is obtained, the data is transferred to the halftone processing module 165d. The halftone processing module 165d is a module that performs halftone processing for converting the large, medium, and small dots of each color and expressing them by the recording density of the ink droplets, and records the large, medium, and small ink droplets at the converted recording density. Generate data for The print data generation module 165e receives this data and performs a rearrangement process for rearranging in the order used by the printer 200. After the rearrangement process, print data is generated by adding predetermined information such as image resolution and output to the printer 200 via the USB I / F 190b. The printer 200 prints the image displayed on the display based on the print data.

  In this printing process, the large, medium, and small dots are sorted with reference to the large, medium, and small sorting table created for each printing condition, so that color matching can be accurately performed for each printing condition. The above description is a very general-purpose printing process in the PRTDRV 165 that controls a printer capable of recording N types of ink droplets. Therefore, color matching can be performed only by making the large / medium / small distribution table created according to the present invention usable in combination with the reference LUT, and the hardware configuration is not changed at all in many printers. Very accurate color matching can be performed with resources. Further, not all the LUTs for each printing condition used in the conventional printing process are necessary, and only the reference LUT 122b may be used as the LUT.

In the present invention, it suffices that the color matching can be performed by diverting the LUT of the standard printing conditions and creating a large / medium / small distribution table in an arbitrary printing condition. This embodiment can be adopted. For example, in the above embodiment, when creating the large / medium / small distribution table, the reference correspondence and the colorimetric correspondence are compared in the L ^* a ^* b ^* space as shown in FIG. A simple configuration can also be adopted.

That is, the reference correspondence relationship and the colorimetric correspondence relationship may be compared with only one of the L ^* a ^* b ^* components. Of course, the color component to be compared may be changed for each ink color. With this configuration, the target gradation value and the large, medium, and small dot recording amounts can be associated with each other by a very simple calculation. Further, an intermediate printing condition among a plurality of printing conditions may be handled by interpolation calculation.

  For example, in a printer capable of selecting a large number of resolutions, a large, medium, and small sorting table is created in advance for a plurality of resolutions, and the large, medium, and small dot recording amounts are created for intermediate resolutions of the plurality of resolutions. What is necessary is just to calculate from the large, medium and small dot recording amounts in the small and medium distribution table. With this configuration, color matching can be performed with fewer resources for more printing conditions.

  Further, the above-described large, medium, and small distribution tables 126a and 126b associate the target gradation values with the large, medium, and small dot recording amounts for each color of CMYKlclm, but the gradation values and the recording values for all colors or some of the colors. The correspondence with the quantity may be common. For example, it is possible to adopt a common large / medium / small distribution table in which the C and M inks, which are dark inks, have substantially the same brightness change tendency with respect to the gradation value. Of course, a common large, medium, and small sorting table may be used for more colors or all colors. By creating a large, medium, and small distribution table for each printing condition, color matching can be performed with higher accuracy than in a configuration that uses a common large, medium, and small distribution table for all printing conditions.

  Further, the target gradation values stored as the large, medium, and small distribution tables may be values obtained by dividing the gradation value range equally, or the distribution density may be varied depending on the gradation value range. For example, in general, as the ink recording amount increases (the gradation value increases), the change in the color value with respect to the change in the unit ink recording amount becomes dull. Therefore, it is possible to accurately represent the change in brightness by increasing the ink recording amount in the gradation value range indicating the small ink recording amount. Therefore, the smaller the ink recording amount gradation value, the more the target gradation value may be adopted. With this configuration, it is possible to accurately represent a change in lightness with a small ink recording amount. Of course, it is possible to make the target gradation values non-uniform based on various other criteria.

It is explanatory drawing which illustrates this invention roughly. It is a figure which shows the difference of a resource. It is a block diagram which shows the structural example of a large, medium, and small allocation table preparation apparatus. It is explanatory drawing for demonstrating the distribution rule of a large / medium / small dot. It is explanatory drawing which shows a mode that the allocation table differs for every resolution. It is a creation processing flow of recording amount specific data. It is explanatory drawing of matching with a reference | standard correspondence and a colorimetric correspondence. It is a block diagram of a computer using a large, medium and small distribution table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Computer, 112 ... Patch printing part, 114 ... Color value acquisition part, 116 ... Large / medium / small distribution table creation part, 116a ... Reference | standard correspondence acquisition part, 116b ... Colorimetry correspondence acquisition part, 116c ... Recording amount gradation Value correspondence unit, 122: reference data, 122a, 126a, 126b: large, medium, small distribution module, 124a, 124b: large, medium, small distribution temporary table, 150a: image data, 165a, image data acquisition module, 165b, color conversion module 165c: Large, medium and small distribution module, 165d: Halftone processing module, 165e ... Print data generation module, 200 ... Printer, 300 ... Colorimeter

Claims (11)

Recording for creating recording amount specifying data to be referred to when N types of ink droplets (N is an integer of 2 or more) with different ink amounts are recorded on a printing medium by a printing apparatus capable of printing under a plurality of printing conditions. A device for creating quantity-specific data,
Correspondence relationship between gradation value when expressing the color of the pixel forming the image with gradation for each ink color used in the printing device and color value when printing with the same gradation value under the standard printing condition Reference color value data acquisition means for acquiring reference color value data indicating
Patch printing means for printing a plurality of patches under a predetermined printing condition with a plurality of target recording amounts indicating the recording amount of each of the N types of ink droplets;
Color value data acquisition means for acquiring color value data indicating the color value of the printed patch;
With reference to the acquired color value data and the reference color value data, the color values obtained by printing under the predetermined printing conditions with the recording amounts of the N types of ink droplets, and a plurality of target tone values The recording amount specifying data by associating the recording amount of each ink drop with the target gradation value so that the correspondence relationship of the ink color is substantially equal to the correspondence relationship between the color value and the gradation value defined in the reference color value data. A recording amount specifying data generating device for generating the recording amount specifying data. The reference color value data includes reference color conversion table data in which input gradation values of a plurality of color components in a predetermined color system and gradation values for each ink color are associated with each other, and gradation values for each ink color. And reference recording amount specifying data indicating the corresponding relationship between the recording amounts of the N types of ink droplets, and obtained by converting the input gradation value by the reference color conversion table data and the reference recording amount specifying data. The color value when a patch having a recording amount to be printed under a standard printing condition is adjusted in advance so as to coincide with a color value corresponding to the input gradation value. Recording amount specific data creation device. In the reference recording amount specifying data, the correspondence relationship between the gradation value for each ink color and the recording amount of each ink droplet is a common correspondence relationship for all the ink colors. 2. The recording amount specifying data creating device according to 2. 4. The recording amount specifying data generating device according to claim 1, wherein the recording amount specifying data generating means generates recording amount specifying data individually for each ink color. . 5. The recording amount specifying data creating apparatus according to claim 1, wherein the resolution in the printing apparatus is different for each of the plurality of printing conditions. The patch printing unit obtains recording amount specifying temporary data indicating a provisional correspondence between the gradation value and the recording amount of each of the N types of ink droplets, and refers to the recording amount specifying temporary data to obtain a plurality of pieces. 6. The recording amount specifying data creating apparatus according to claim 1, wherein a gradation value is converted into the plurality of target recording amounts. 7. The recording amount specifying provisional data is created in advance for each of a plurality of printing conditions in consideration of an ink amount per unit ink droplet that is different for each of a plurality of printing conditions. Recording amount specifying data creating device described. The recording amount specifying data creating means obtains color values corresponding to a plurality of target gradation values by referring to the reference color value data, and refers to the recording amount specifying temporary data and the color values of the patch. Acquire the recording amount of each of the N types of ink droplets required to obtain the color value corresponding to the target gradation value, and specify the recording amount under the predetermined printing condition by associating it with the target gradation value 8. The recording amount specifying data creating apparatus according to claim 7, wherein the data is created. The gradation values for each ink color stored in the reference color conversion table data are unevenly distributed in a specific value range from other value ranges, and the recording amount specifying data creating means generates the gradations included in the specific region. 9. The recording amount specifying data creating apparatus according to claim 2, wherein a value is extracted more than other value ranges to obtain a target gradation value. Recording for creating recording amount specifying data to be referred to when N types of ink droplets (N is an integer of 2 or more) with different ink amounts are recorded on a printing medium by a printing apparatus capable of printing under a plurality of printing conditions. A method for creating quantity-specific data,
Correspondence relationship between the gradation value when expressing the color of the pixel forming the image with gradation for each ink color used in the printing device and the color value when printing with the same gradation value under the standard printing conditions A reference color value data acquisition step for acquiring reference color value data indicating
A patch printing step of printing a plurality of patches under a predetermined printing condition with a plurality of target recording amounts indicating the recording amount of each of the N types of ink droplets;
A color value data acquisition step of acquiring color value data indicating the color value of the printed patch;
With reference to the acquired color value data and the reference color value data, the color values obtained by printing under the predetermined printing conditions with the recording amounts of the N types of ink droplets, and a plurality of target tone values The recording amount specifying data by associating the recording amount of each ink droplet with the target gradation value so that the correspondence relationship of the ink droplets is substantially equal to the correspondence relationship between the color value and the gradation value defined in the reference color value data. And a recording amount specifying data creating step for creating a recording amount specifying data. Recording for creating recording amount specifying data to be referred to when N types of ink droplets (N is an integer of 2 or more) with different ink amounts are recorded on a printing medium by a printing apparatus capable of printing under a plurality of printing conditions. A volume identification data creation program,
Correspondence relationship between gradation value when expressing the color of the pixel forming the image with gradation for each ink color used in the printing device and color value when printing with the same gradation value under the standard printing condition A reference color value data acquisition function for acquiring reference color value data indicating a predetermined recording medium;
A patch printing function for printing a plurality of patches under a predetermined printing condition with a plurality of target recording amounts indicating the recording amount of each of the N types of ink droplets;
A color value data acquisition function for acquiring color value data indicating the color value of a printed patch;
With reference to the acquired color value data and the reference color value data, the color values obtained by printing under the predetermined printing conditions with the recording amounts of the N types of ink droplets, and a plurality of target tone values The recording amount specifying data by associating the recording amount of each ink drop with the target gradation value so that the correspondence relationship of the ink color is substantially equal to the correspondence relationship between the color value and the gradation value defined in the reference color value data. A recording amount specifying data creating program for causing a computer to realize a recording amount specifying data creating function for creating a recording amount.

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