JP5097656B2 - Printing color prediction method and prediction system - Google Patents

Description

  The present invention relates to a print color prediction method and a prediction system for predicting the color of a printed material created using a printing press.

  For example, a printed material for each color of C, M, Y, and K is prepared, and a PS plate (Presitized Plate) is printed from each film original and developed, and then the PS plate is printed on a printing machine such as a rotary press. It is created by adjusting printing conditions such as ink film thickness, fountain solution, and temperature.

  Thus, the printed material is created through a complicated process. Therefore, in order to obtain a printed matter having a desired hue, a proof is created using a simple output device such as a monitor or a color printer prior to the creation of the printed matter, so that the proof becomes a target shade of the printed matter. Work to adjust printing conditions is performed.

  For example, in Patent Document 1, color charts are created and measured by an output device such as a printing press and a color printer, respectively, and halftone dots% and colorimetric values of C, M, Y, and K inks are measured. An ICC (International Color Consortium) profile representing a correspondence relationship is obtained, and a method for creating a proof of a printed matter using the ICC profile is disclosed. In this case, the density of the printed matter is usually defined by the printing company as a user as the standard density of a solid image (an image with halftone dots of 100%), and printing is performed so that this standard density can be obtained. Printing conditions such as ink film thickness in the machine are adjusted.

JP 2006-128760 A

  By the way, the reference density of the printed matter may differ depending on the user who desires the printed matter. When the reference density is changed, the color chart must be printed again to recreate the ICC profile. In this case, since a color chart made up of a large number of color patches must be printed and measured according to the new reference density, the processing takes a lot of time.

  When creating printed matter, not only the density desired by the user, but also printing conditions such as dot gain due to the influence of the printing paper, ink, and blanket used for printing, and the operating environment temperature or humidity of the printing press. It is necessary to consider. When these printing conditions change, the color reproduction characteristics also change. Therefore, as in the case of changing the reference density, it is necessary to create an ICC profile by printing a color chart under the changed printing conditions. Further processing time is required.

  The present invention has been made to solve the above-described problems, and a printing color prediction method capable of predicting the color of a printed matter with high accuracy in response to a change in printing conditions easily and quickly, and An object is to provide a prediction system.

The print color prediction method of the present invention is a print color prediction method for predicting the color of a printed matter created using a printing press.
Creating a first reference color chart having a reference density according to the first printing condition, and measuring the first reference color chart to obtain a first reference measurement value under the first printing condition;
In accordance with the first printing condition, the density of each color material for creating the printed matter is changed from the reference density to a predetermined amount independently, while the density of other color materials except the color material whose density is changed is changed. Creating a changed color chart fixed to the reference density, and determining the changed measured value by measuring the changed color chart;
Obtaining a difference amount between the first reference measurement value and the changed measurement value for each color material;
Creating a second reference color chart having the reference density according to a second printing condition, and measuring the second reference color chart to obtain a second reference measurement value under the second printing condition;
Predicting the color of the printed matter at the desired density according to the second printing condition using the second reference measurement value and the difference amount of each color material corresponding to the desired density;
It is characterized by including.

Further, the print color prediction system of the present invention is a print color prediction system for predicting the color of a printed matter created using a printing press.
A first reference measurement value obtained by measuring a first reference color chart composed of a reference density created according to the first printing conditions, and the density of each color material for creating the printed material according to the first printing conditions, A change obtained by measuring a change color chart created by fixing the density of other color materials except the color material whose density is changed to the reference density while changing the reference density to a predetermined amount independently. A difference amount calculation unit for calculating a difference amount with a measured value for each color material;
Using the second reference measurement value obtained by measuring the second reference color chart composed of the reference density created according to the second printing condition, and the difference amount of each color material corresponding to the desired density, A profile creation unit that creates a print prediction profile for predicting the color of the printed matter at the desired density according to a second printing condition;
And predicting the color of the printed matter using the print prediction profile.

  In the printing color prediction method and the prediction system of the present invention, when creating a printed matter by changing the printing conditions, a desired printing prediction profile can be easily and quickly created by merely creating a minimum color chart based on the printing conditions. The color of the printed matter can be predicted with high accuracy by using this print prediction profile.

  FIG. 1 shows a print color prediction system 10 of the present embodiment. The print color prediction system 10 uses an editing device 12 that edits image data C1, M1, Y1, and K1 for controlling C, M, Y, and K colors, and edited image data C1, M1, Y1, and K1. A printer 14 that creates a printed matter P1, a color conversion device 16 that converts the image data C1, M1, Y1, and K1 into image data C2, M2, Y2, and K2 for color prediction, and image data C2, M2. , Y2, and K2, the printer 18 that creates the proof P2 of the printed matter P1, and the profile creation device 24 that creates the print prediction profile 20 and the printer profile 22 (output profile) incorporated in the color conversion device 16 are provided.

The print prediction profile 20 predicts colorimetric values that do not depend on the device of the printed matter P1 created by the printing machine 14, for example, colorimetric values X, Y, Z or colorimetric values L ^* , a ^* , b ^*. Based on the known image data C, M, Y, K and the measured values of the color chart C1 created from the image data C, M, Y, K by using the printing machine 14 It is created by the creation device 24.

The printer profile 22 uses the colorimetric values, for example, the colorimetric values X, Y, Z or the colorimetric values L ^* , a ^* , b ^*, which are not dependent on the device of the printed matter P1 predicted by the print prediction profile 20, to the printer 18. Is a profile for conversion to image data C, M, Y, K depending on the output characteristics of the image data. The known image data C, M, Y, K and the image data C, M, Y, K to the printer 18 Is created by the profile creation device 24 based on the measured values of the color chart C2 created by using.

  The color charts C1 and C2 are primary colors (single colors) created by setting the dot percentage of each ink (color material) of C, M, Y, and K to a predetermined interval in the range of 0 to 100%. It is composed of a large number of quaternary color patches.

  FIG. 2 is a configuration block diagram of a function for creating the print prediction profile 20 in the profile creation device 24.

  The profile creation device 24 includes a spectral reflectance measuring device 34 that measures the spectral reflectance of the color chart C1 (first reference color chart, second reference color chart, and changed color chart), and a spectral that stores the measured spectral reflectance. A reflectance storage unit 36, a spectral reflectance difference amount calculation unit 38 that calculates the difference amount of the measured spectral reflectances, a spectral reflectance difference amount storage unit 40 that stores the spectral reflectance difference amount, and C, M, A target density spectral reflectance that can obtain a target density using a target density setting unit 46 that sets a desired target density for each color of Y and K, and a target density, a spectral reflectance, and a spectral reflectance difference amount. The target density spectral reflectance calculating unit 48 for calculating the print density and the print predicted profile creating unit 50 for creating the print predicted profile 20 using the target density spectral reflectance.

FIG. 3 is a block diagram showing the function of creating the printer profile 22 in the profile creation device 24. The profile creation device 24 includes a colorimeter 52 that measures the colorimetric values of the color chart C2 created by the printer 18, for example, the colorimetric values X, Y, Z, or the colorimetric values L ^* , a ^* , b ^* , And a printer profile creation unit 54 that creates the printer profile 22 using the measured colorimetric values.

  The print color prediction system 10 of the present embodiment is basically configured as described above. Next, a print color prediction method using the print color prediction system 10 will be described with reference to the flowchart shown in FIG. This will be explained based on.

  First, image data C1, M1, Y1, and K1 known from the editing device 12 under the first printing condition with dot gain due to the effect of switching of predetermined printing paper, ink, and blanket or the use environment temperature or humidity of the printing machine 14. Is set to the printer 14 so that the single-color solid density of the color patch becomes the reference density, and the color chart C1 (first reference color chart) is printed (step S1). In this case, halftone dots% of the image data C1, M1, Y1, and K1 are set at predetermined intervals in the range of 0% to 100%, and a color chart C1 composed of a plurality of color patches is created. The reference density can be set to a density specified by a printing company as a user, for example.

  The color chart C1 created by the printing machine 14 is measured for spectral reflectance by the spectral reflectance measuring device 34 (step S2), and is spectrally reflected as a reference density spectral reflectance (first reference measured value) under the first printing conditions. It is stored in the rate storage unit 36 (step S3).

  Next, the reference density of the printing machine 14 under the first printing condition is changed, and the image data C1, M1, and the image data having a predetermined interval in the range of 0% to 100%, which is the same as when the color chart C1 in step S1 is created. A color chart C1 (changed color chart) is printed using Y1 and K1 (step S4).

  In this case, in the color chart C1, the reference density of the color patch created by each of the C, M, Y, and K inks whose halftone dot% is set to 100% is independently changed by a predetermined change amount for each ink. On the other hand, the density of the ink other than the ink to be changed is fixed to the reference density. Note that the changed density is set such that the optical density is −0.2, −0.1, +0.1, +0.2 with respect to the reference density, for example. Therefore, in the color chart C1 to be created, 100% of each color of C, M, Y, and K is changed to the reference density −0.2, the reference density −0.1, the reference density +0.1, and the reference density +0.2. The set 16 sheets.

  The spectral reflectances of the plurality of color charts C1 after density change created by the printing machine 14 under the first printing conditions are measured by the spectral reflectance measuring device 34 (step S5), and the density changes under the first printing conditions are performed. The spectral reflectance (changed measurement value) is stored in the spectral reflectance storage unit 36 (step S6).

Here, for example, the reference density spectral reflectance of a single color solid density patch consisting only of C100% is R _{C (std)} , and the standard density spectral reflectance of a single color solid density patch consisting only of M100% is R _{M (std)} , C100. Changed density spectral reflectance by changing the density of a single color solid density patch consisting of only% by a predetermined amount (R _{C (std)} + ΔR _C ), and changing the density of a single color solid density patch consisting of only M100% by a predetermined amount _Assuming that the density spectral reflectance is (R _{M (std)} + ΔR _M ), the changed density spectral reflectance R _CM when the density of the color patch composed of halftone dots of C100% and M100% is changed by the same predetermined amount is Ideally
R _CM = (R _{C (std)} + ΔR _C ) · (R _{M (std)} + ΔR _M )
= _{RC (std)}・_{RM (std)}
+ {R _{M (std)} · (R _{C (std)} + ΔR _C ) −R _{C (std)} · R _{M (std)} }
+ {R _{C (std)} · (R _{M (std)} + ΔR _M ) −R _{C (std)} · R _{M (std)} }
+ ΔR _C · ΔR _M (1)
It can be expressed as. In this case, assuming that the fourth term on the right side of the equation (1) is 0 as a minute amount, the first term on the right side represents the reference density spectral reflectance of the color patch composed of halftone dots of C100% and M100%. The second term represents the difference amount from the reference density spectral reflectance of the changed density spectral reflectance when the density of only C100% of the color patch composed of halftone dots of C100% and M100% is changed by a predetermined amount. The third term on the right-hand side is the difference amount from the reference density spectral reflectance of the changed density spectral reflectance when the density of only M100% of the color patch composed of C100% and M100% halftone dots is changed by a predetermined amount. Represents.

Therefore, the changed density spectral reflectance R _CM when the density of both the C and M colors is changed is the spectral reflectance when the other density is changed while one of the C or M density is fixed. the amount of difference rate can be obtained by adding the standard density spectral reflectance at reference density _{R C (std) · R M} (std).

FIG. 5 shows the reference density spectral reflectance R _{CM (std)} of a color patch composed of C100% of the reference density and halftone dot% of M100%, C100% is fixed to the reference density, and only M100% is (reference density− 0.1) Color patch changed density spectral reflectance R _{CM (M-0.1)} and color patch with M100% fixed to the reference density and only C100% changed to (reference density -0.1) The changed density spectral reflectance R _{CM (C-0.1) of} the color patch and the changed density spectral reflectance R _{CM (ALL-0.1)} of the color patch in which both C100% and M100% are changed to (reference density −0.1) The measurement results are shown.

FIG. 6 shows the reference density spectral reflectance R _{CM (std)} of a color patch composed of halftone dots of C100% and M100% created at the reference density, and C100% is fixed to the reference density, and only M100%. Color patch change density reflectance R _{CM (M + 0.1)} with _M changed to (reference density +0.1), M100% is fixed to the reference density, and only C100% is changed to (reference density +0.1) Changed density spectral reflectance R _{CM (C + 0.1) of} the color patch and C100% and M100% are both changed to (reference density +0.1), and the changed density spectral reflectance R _{CM (ALL + 0.1) of the} color patch The measurement results are shown.

In this case, the modified density spectral reflectance R _{CM (ALL-0.1)} is
R _{CM (ALL-0.1)} = R _{CM (std)} + (R _{CM (C-0.1)} -R _{CM (std)} )
+ (R _{CM (M-0.1)} -R _{CM (std)} )
As a result, the modified spectral reflectance R _{CM (ALL + 0.1)} is
R _{CM (ALL + 0.1)} = R _{CM (std)} + (R _{CM (C + 0.1)} -R _{CM (std)} )
+ (R _{CM (M + 0.1)} -R _{CM (std)} )
Is approximately obtained.

From the above results, the target density spectral reflectance R, which is the target spectral reflectance when C, M, Y, and K are changed to arbitrary target densities, is the reference density spectral reflectance of R _std , C only. The spectral reflectance difference amount when the density is changed is RΔ _C , the spectral reflectance difference amount when only the density of M is changed is RΔ _M , and the spectral reflectance difference amount when the density of only Y is changed is RΔ _Y. the spectral reflectance difference amount when changing the concentration of K only when the Aruderuta _K, from equation (1),
_{R = R std + RΔ C +} RΔ M + RΔ Y + RΔ K ... (2)
As an approximation.

Therefore, the spectral reflectance difference amount calculation unit 38 individually sets the reference density spectral reflectance R _{std of the} color chart C1 including the reference density and the density of each ink of C, M, Y, and K by a predetermined amount from the reference density. Each change density spectral reflectance of the color chart C1 (changed color chart) created by changing to is read from the spectral reflectance storage unit 36, and the spectral reflectance difference amounts RΔ _C , RΔ _M , RΔ that are the differences between them are read out. _Y, and calculates the RΔ _K (step S7). Note that the spectral reflectance difference amounts RΔ _C , RΔ _M , RΔ _Y , and RΔ _K are, for example, 100% C, M, Y, and K color densities with reference density −0.2, reference density −0,. 1. It is obtained by setting the reference density +0.1 and the reference density +0.2. The calculated spectral reflectance difference amounts RΔ _C , RΔ _M , RΔ _Y , RΔ _K are stored in the spectral reflectance difference amount storage unit 40 (step S8).

  By the way, each term of the formula (2) is a reference density spectral reflectance and a spectral reflectance difference amount obtained using the color chart C1 created by the printer 14 under the first printing condition. On the other hand, when the printing conditions of printing paper, ink, and dot gain change, the color of the printed matter P1 also changes.

  Therefore, next, the printing condition is changed to the second printing condition, the printer 14 is set to the same reference density as the first printing condition, and the color chart C1 (second reference color chart) is set as in step S1. ) Is printed (step S9).

  The spectral reflectance of the printed color chart C1 is measured by the spectral reflectance measuring device 34 (step S10), and the spectral reflectance storage unit 36 is used as the reference density spectral reflectance (second reference measurement value) in the second printing condition. (Step S11).

  After the above preparation processing is completed, a print prediction profile 20 is created under the second printing condition when the reference density is changed to an arbitrary target density.

When a desired target density for each color of C, M, Y, and K is set using the target density setting unit 46 (step S12), the target density spectral reflectance calculation unit 48 stores in the spectral reflectance storage unit 36. The spectral reflectance difference amount RΔ _C stored in the spectral reflectance difference amount storage unit 40 corresponding to the stored reference density spectral reflectance R _std in the second printing condition and the changed density equal to the target density of each color. , RΔ _M , RΔ _Y and RΔ _K are substituted into the equation (2) to calculate the target density spectral reflectance R (step S13).

In this case, the spectral reflectance difference amounts RΔ _C , RΔ _M , RΔ _Y and RΔ _K are calculated under the first printing conditions, but the difference amounts are very small and are almost affected by the printing conditions. It can be regarded as not. The change in the spectral reflectance due to the change of the printing conditions mostly depends on the reference density spectral reflectance. Therefore, the target density spectral reflectance R under the second printing condition does not need to obtain the difference amount under the second printing condition, and is obtained under the reference density spectral reflectance obtained under the second printing condition and the first printing condition. By using the spectral reflectance difference amount, the target density spectral reflectance R can be obtained with sufficient accuracy.

For example, when changing only the C reference density to the target density, only the C spectral reflectance difference amount RΔ _{C to} be changed is used, and the other spectral reflectance difference amounts RΔ _M , RΔ _Y , RΔ _K are set to 0. A target density spectral reflectance R is calculated. Also, when changing the C and M reference densities to the target densities, the C and M spectral reflectance difference amounts RΔ _C and RΔ _M to be changed are used, and the other spectral reflectance difference amounts RΔ _Y and RΔ _K are set to 0. As a result, the target density spectral reflectance R is calculated.

Here, when the reference densities of all four colors C, M, Y, and K are changed to the target densities, the target density spectral reflectance R can be calculated according to the equation (2). However, for example, when the target color patch for calculating the target density spectral reflectance R is composed of three colors C, M, and Y, the spectral reflectance difference amount RΔ _K is ideal regardless of the K density change. In reality, it should be 0, but in reality, it may not become 0 due to the influence of variations in printing and measurement.

Therefore, even when the reference densities of all four colors C, M, Y, and K are changed to the target densities, the target color patches for calculating the target density spectral reflectance R are C, M, and Y. when a three-color, it is desirable to calculate the target density spectral reflectance R the spectral reflectance difference amount Aruderuta _K is set to 0. Similarly, when the target color patch for calculating the target density spectral reflectance R is composed of two colors C and M, the spectral reflectance difference amounts RΔ _Y and RΔ _K are set to 0 to set the target density spectral reflectance. It is desirable to calculate the reflectance R.

Next, the print prediction profile creation unit 50 calculates, for example, the colorimetric values X, Y, Z or the colorimetric values L ^* , a from the target density spectral reflectance R obtained under the second printing conditions as described above. ^* , B ^* are calculated (step S14), and the colorimetric values X, Y, Z or the colorimetric values L ^* , a ^* , b ^* and the image data C1, M1, Y1 used to create the color chart C1 are calculated. , K1 is generated (step S15). The print prediction profile 20 created according to the desired change density is set in the color conversion device 16.

  On the other hand, when the image data C2, M2, Y2, and K2 are supplied from the color conversion device 16 to the printer 18 and the color chart C1 is printed, the color chart C2 composed of a plurality of color patches is recorded in the same manner as in step S1. Output above (FIG. 7, step S21).

For each color patch of the output color chart C2, the colorimeter 52 measures the colorimetric values, for example, the colorimetric values X, Y, Z or the colorimetric values L ^* , a ^* , b ^* (step S22). ). The printer profile creation unit 54 then measures the measured colorimetric values X, Y, Z or the colorimetric values L ^* , a ^* , b ^*, and the image data C2, M2, Y2, A printer profile 22 having a relationship with K2 is created (step S23). The created printer profile 22 is set in the color conversion device 16. Since the printer profile 22 does not depend on the changed density condition, the printer profile 22 need only be set once as long as the conditions of the printer 18 do not change.

  After setting the print prediction profile 20 and the printer profile 22 as described above, a proof P2 for a printed matter P1 obtained from desired image data C1, M1, Y1, and K1 is created.

The editing device 12 creates desired image data C1, M1, Y1, and K1 and supplies them to the color conversion device 16 (FIG. 8, step S31). In the color conversion device 16, using the print prediction profile 20, the image data C1, M1, Y1, and K1 are colorimetric values that do not depend on the device, for example, the colorimetric values X, Y, and Z or the colorimetric values L ^* , a ^{* And} b ^* are converted (step S32). In this case, the print prediction profile 20 is adjusted so that each color of C, M, Y, and K has a desired target density at 100% halftone dot%.

Next, the colorimetric values X, Y, Z or the colorimetric values L ^* , a ^* , b ^* are converted into image data C2, M2, Y2, K2 depending on the output characteristics of the printer 18 by the printer profile 22 (step). S33), the proof P2 is created using the image data C2, M2, Y2, and K2 (step S34).

  The print prediction profile 20 and the printer profile 22 are combined into one profile, and the image data C2, M2, Y2, and K2 are obtained directly from the image data C1, M1, Y1, and K1 using this profile. Good.

  Further, instead of measuring the spectral reflectance of the color chart C1 using the spectral reflectance measuring device 34, the spectral density of the color chart C1 is measured using a spectral densitometer, and the print prediction profile 20 is created from this spectral density. You can also

In this case, for example, the spectral density at the reference density of the color chart C1 consisting only of C100% is D _{C (std)} and the spectral density at the reference density of the color chart C1 consisting only of M100% is D _{M (std)} , C100. % (D _{C (std)} + ΔD _C ), and the spectral density at the predetermined change density of the color chart C1 consisting only of M100% (D _{M (std )} + ΔD _M ), the spectral density D _CM when the color chart C1 composed of halftone dots of C100% and M100% is created with a predetermined change density is:
D _CM = (D _{C (std)} + ΔD _C ) + (D _{M (std)} + ΔD _M )
= (D _{C (std)} + D _{M (std)} )
+ [{(D _{C (std)} + D _{M (std)} ) + ΔD _C }
− (D _{C (std)} + D _{M (std)} )]
+ [{(D _{C (std)} + D _{M (std)} ) + ΔD _M }
− (D _{C (std)} + D _{M (std)} )] (3)
It can be expressed as. In this case, the first term on the right side of equation (3) represents the reference spectral density when the color chart C1 composed of halftone dots of C100% and M100% is created with the reference density, and the second term on the right side is C100%. And the difference amount from the reference density of the spectral density when only the density of C100% of the color chart C1 composed of dot percentage of M100% is changed to a predetermined change density, the third term on the right side is C100% and This represents the amount of difference from the spectral density at the reference density when the density of only M100% of the color chart C1 composed of halftone dots of M100% is changed to a predetermined change density.

Accordingly, the spectral density D _CM when the densities of both the colors C and M are changed is the same as the changed density spectral reflectance R _CM when the density of one of C and M is fixed. It is possible to calculate by adding the difference amount when the value is changed to the reference spectral density (D _{C (std)} + D _{M (std)} ) at the reference density. Moreover, unlike the change density spectral reflectance Request R _CM (1) formula, because there is no term ΔR _C · ΔR _M, which becomes an error, it is possible to obtain the spectral density D _CM with high accuracy.

As a result, in the profile creation device 24, the target spectral density D when C, M, Y, and K are changed to arbitrary densities at a desired changed density is the reference spectral density D _std and the density of C alone is changed. The spectral density difference amount is DΔ _C , the spectral density difference amount when the density of M alone is changed, DΔ _M , the spectral density difference amount when the density of Y alone is changed, DΔ _Y , and the density of K alone is changed was spectral density difference amount when the as d? _K, as with (2),
D = D _std + DΔ _C + DΔ _M + DΔ _Y + DΔ _K (4)
Can be obtained with high accuracy. The print prediction profile 20 can be obtained from the target spectral density D thus obtained.

In the case where a color patch to be used to calculate the target spectral density D is C, M, consists of three colors of Y, the spectral density difference amount d? _K is set to 0 to calculate the target spectral density D It is desirable. Similarly, when the target color patch for calculating the target spectral density D is composed of two colors C and M, the spectral density difference amounts DΔ _Y and DΔ _K are set to 0 to calculate the target spectral density D. It is desirable to do.

  Also, the print prediction profile 20 can be created using colorimetric density or colorimetric value instead of spectral reflectance or spectral density.

  By the way, in each of the above descriptions, the print prediction profile 20 corresponding to the density change from the reference density is obtained, but the maximum density and the minimum density of C, M, Y, and K that can be printed by the printing machine 14 are determined. It is also possible to set the intermediate density in between as the reference density, and create the print prediction profile 20 based on the reference density color chart and the changed density color chart created based on this intermediate density. The intermediate density can be set as an average value of the maximum density and the minimum density, or an arbitrary density between the maximum density and the minimum density.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

  For example, the print color prediction system 10 is configured to create the proof P2 using the printer 18, but instead of the printer 18, for example, the proof P2 may be displayed on a color monitor. In this case, the profile creation device 24 creates a monitor profile by measuring the color chart C2 displayed on the color monitor, and sets this monitor profile in the color conversion device 16.

  Further, the present invention is not limited to the case where the print prediction profile 20 for the four colors C, M, Y, and K is created. Can do.

  Furthermore, the color material used for the printed material P1 is not limited to ink, and for example, toner can be used.

It is a block diagram of the printing color prediction system of this embodiment. FIG. 2 is a configuration block diagram of a function for creating a print prediction profile in the profile creation apparatus shown in FIG. 1. FIG. 2 is a configuration block diagram of a function for creating a printer profile in the profile creation apparatus shown in FIG. 1. It is a creation flowchart of a printing prediction profile. It is explanatory drawing of the spectral reflectance with respect to reference | standard density | concentration conditions and change density | concentration conditions. It is explanatory drawing of the spectral reflectance with respect to reference | standard density | concentration conditions and change density | concentration conditions. 6 is a flowchart for creating a printer profile. It is a creation flowchart of a proof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Print color prediction system 12 ... Editing apparatus 14 ... Printing machine 16 ... Color conversion apparatus 18 ... Printer 20 ... Print prediction profile 22 ... Printer profile 24 ... Profile creation apparatus 34 ... Spectral reflectance measuring device 36 ... Spectral reflectance storage part 38 ... Spectral reflectance difference calculation unit 40 ... Spectral reflectance difference storage unit 46 ... Target density setting unit 48 ... Target density spectral reflectance calculation unit 50 ... Print prediction profile creation unit 52 ... Colorimeter 54 ... Printer profile creation Part C1, C2 ... color chart P1 ... printed matter P2 ... proof

Claims (21)

In a printing color prediction method for predicting the color of a printed matter created using a printing press,
A first reference color chart having a reference density is created in accordance with a first printing condition that is a condition relating to a color change of the printed matter, and the first reference color chart is measured to measure the first reference color chart. Obtaining one reference measurement value;
In accordance with the first printing condition, the density of each color material for creating the printed matter is changed from the reference density to a predetermined amount independently, while the density of other color materials except the color material whose density is changed is changed. Creating a changed color chart fixed to the reference density, and determining the changed measured value by measuring the changed color chart;
Obtaining a difference amount between the first reference measurement value and the changed measurement value for each color material;
According to a second printing condition different from the first printing condition, a second reference color chart composed of the reference density is created, and the second reference color chart is measured, whereby a second reference measurement under the second printing condition is performed. Determining a value;
Predicting the color of the printed matter at the desired density according to the second printing condition using the second reference measurement value and the difference amount of each color material corresponding to the desired density;
A printing color prediction method comprising: The method of claim 1, wherein
Predicting the color of the printed matter at the desired density according to the second printing condition by adding the second reference measurement value and the difference amount of each color material corresponding to the desired density. A characteristic print color prediction method. The method according to claim 1 or 2 ,
Interpolating the difference amount of each color material to obtain an interpolation difference amount of each color material corresponding to the desired density,
Printing color prediction, wherein the color of the printed matter at the desired density according to the second printing condition is predicted by adding the second reference measurement value and the interpolation difference amount of each color material Method. In the method of any one of Claims 1-3,
The print color prediction method, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are spectral reflectances. In the method of any one of Claims 1-3,
The print color prediction method, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are spectral densities. In the method of any one of Claims 1-3,
The print color prediction method, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are colorimetric densities. In the method of any one of Claims 1-3,
The print color prediction method, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are colorimetric values. In the method of any one of Claims 1-7 ,
The printing color prediction method, wherein the first printing condition and the second printing condition are conditions relating to a printing paper used for the printed matter. In the method of any one of Claims 1-7 ,
The printing color prediction method, wherein the first printing condition and the second printing condition are conditions relating to a color material for creating the printed matter. In the method of any one of Claims 1-7 ,
The printing color prediction method, wherein the first printing condition and the second printing condition are conditions related to dot gain of the printed matter. In a printing color prediction system that predicts the color of a printed matter created using a printing press,
A first reference measurement value obtained by measuring a first reference color chart having a reference density created according to a first printing condition, which is a condition relating to a color change of the printed matter, and the printed matter according to the first printing condition. The density of each color material for creating a color is changed from the reference density to a predetermined amount alone, while the density of other color materials except the color material whose density is changed is fixed to the reference density. A difference amount calculation unit that calculates a difference amount with a change measurement value obtained by measuring the changed color chart for each color material;
A second reference measurement value obtained by measuring a second reference color chart composed of the reference density created according to a second printing condition different from the first printing condition, and the difference between the color materials corresponding to a desired density A profile creation unit that creates a print prediction profile that predicts the color of the printed matter at the desired density according to the second printing condition using a quantity;
And predicting the color of the printed matter using the print prediction profile. The system of claim 11, wherein
An output profile for converting the predicted color value of the printed matter calculated using the predicted print profile into output data of an output device, and outputting the proof of the printed matter by the output device using the output profile. Print color prediction system. The system according to claim 11 or 12 ,
The profile creation unit creates a color prediction value obtained by adding the second reference measurement value and the difference amount of each color material corresponding to the desired density as the print prediction profile. Print color prediction system. The system according to any one of claims 11 to 13 ,
The profile creation unit obtains an interpolation difference amount of each color material corresponding to the desired density by interpolating the difference amount of each color material, and calculates the second reference measurement value and the interpolation of each color material. A print color prediction system, wherein a color prediction value obtained by adding a difference amount is created as the print prediction profile. The system according to any one of claims 11 to 14 ,
The print color prediction system, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are spectral reflectances. The system according to any one of claims 11 to 14 ,
The print color prediction system, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are spectral densities. The system according to any one of claims 11 to 14 ,
The print color prediction system, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are colorimetric densities. The system according to any one of claims 11 to 14 ,
The print color prediction system, wherein the first reference measurement value, the changed measurement value, and the second reference measurement value are colorimetric values. The system according to any one of claims 11 to 18 ,
The printing color prediction system, wherein the first printing condition and the second printing condition are conditions relating to a printing paper used for the printed matter. The system according to any one of claims 11 to 18 ,
The printing color prediction system, wherein the first printing condition and the second printing condition are conditions relating to a color material for creating the printed matter. The system according to any one of claims 11 to 18 ,
The printing color prediction system, wherein the first printing condition and the second printing condition are conditions related to dot gain of the printed matter.

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