CN119248207A - Printing method, system and computer-readable storage medium for simulating kraft paper printing digital draft - Google Patents

Abstract

The present invention provides a printing method and a printing system for simulating kraft paper printing digital manuscripts and a computer-readable storage medium. The printing method comprises: S1: determining color feature data of a pattern of a digital manuscript printed on real kraft paper; S2: generating a target feature file based on the color feature data; S3: adding simulated kraft paper color and simulated kraft paper texture; S4: determining CMYK four-color values of the simulated kraft paper color; and S5: printing the digital manuscript based on the target feature file, the CMYK four-color values of the simulated kraft paper color and the simulated kraft paper texture to obtain a simulated kraft paper printing digital manuscript. The printing method provides a standard basis for the printing of kraft paper, can ensure the printing effect, and can save complex printing processes and costs.

Description

Printing method, system and computer readable storage medium for simulating kraft printing digital manuscript

Technical Field

The present invention relates generally to the field of printing technology, and more particularly, to a printing method for simulating kraft printing digital manuscripts, a printing system for simulating kraft printing digital manuscripts, and a computer-readable storage medium.

Background

With the increasing diversity of printed matters, kraft paper is used as a common special paper and is increasingly applied to the printing field. International printing industry standard ISO 12647-7 defines a standard for digital proofing, and the applicable papers specified include class 8 but not kraft paper. International printing industry standard ISO 12647-2 defines a standard for conventional offset printing, nor does the applicable paper specified include kraft paper, nor does it relate to the printing requirements of kraft paper. Because kraft paper itself has unique coating characteristics and colors, and international printing standards do not prescribe printing standards for kraft paper, printing of kraft paper has no reference standard basis, printing has randomness, printing effect is difficult to ensure, and complicated printing processes increase cost. Therefore, a new solution is needed to solve the above technical problems.

The matters in the background section are only those known to the inventors and do not, of course, represent prior art in the field.

Disclosure of Invention

Aiming at one or more of the problems in the prior art, the invention provides a printing method for simulating kraft paper to print digital manuscripts, which comprises the following steps:

S1, determining color characteristic data of patterns of the digital manuscript printed on real kraft paper;

S2, generating a target characteristic file based on the color characteristic data;

s3, adding simulated kraft paper color and simulated kraft paper texture;

S4, determining CMYK four color values of the simulated kraft paper color, and

And S5, printing the digital manuscript based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture to obtain the simulated kraft paper printing digital manuscript.

Optionally, the step S1 includes the following sub-steps:

S11, printing priming white ink on real kraft paper to obtain LAB value and density value of the priming white ink meeting preset requirements;

s12, printing CMYK four colors on the priming white ink meeting the preset requirements to obtain density values of the CMYK four colors;

S13, printing the digital manuscript on white paper to obtain a first sample;

S14, printing the pattern of the digital manuscript on real kraft paper based on the density values of the CMYK four colors and the density value of the priming white ink meeting the preset requirements to obtain a second sample sheet;

S15, optimizing the second sample based on the first sample to obtain an optimized curve;

S16, printing the pattern of the digital manuscript on real kraft paper based on the density values of the CMYK four colors, the density values of the priming white ink meeting the preset requirements and the optimized curve to obtain a third sample sheet, and

And S17, obtaining the color characteristic data based on the third sample.

Optionally, the step of optimizing the second sample includes optimizing the brightness and/or chromaticity of the second sample until the brightness variation is within a preset brightness variation range and/or the chromaticity variation is within a preset chromaticity variation range.

Optionally, the step of optimizing the brightness of the second sample sheet comprises the steps of determining a brightness characteristic curve of the second sample sheet and optimizing the brightness characteristic curve until the brightness variation is within the preset brightness variation range.

Optionally, the brightness characteristic curve comprises a brightness variation curve with a dot gain value, wherein the brightness variation comprises an average brightness variation and a maximum brightness variation, and the brightness variation is within the preset brightness variation range, and/or the average brightness variation is within a first preset range and/or the maximum brightness variation is within a second preset range.

Optionally, the step of optimizing the chromaticity of the second sample sheet comprises the steps of determining a chromaticity characteristic curve of the second sample sheet and optimizing the chromaticity characteristic curve until the chromaticity variation is within the preset chromaticity variation range.

The chromaticity characteristic curve comprises a chromaticity variation curve with a dot gain value, wherein the chromaticity variation comprises an average chromaticity variation and a maximum chromaticity variation, and the chromaticity variation is within the preset chromaticity variation range, and/or the average chromaticity variation is within a first preset range and/or the maximum chromaticity variation is within a second preset range.

Optionally, the first preset range includes a range of 3 or less, and the second preset range includes a range of 5 or less.

Optionally, the substep S17 comprises the substeps of:

s171, collecting a TC1617 color chart of the third printing sample;

And S172, obtaining the color characteristic data based on the TC1617 color table, wherein the color characteristic data comprises LAB values.

Optionally, the step S4 includes:

S41, determining LAB values of the real kraft paper;

S42, obtaining CMYK four color values of the simulated kraft paper based on the LAB value of the real kraft paper.

Optionally, the step S42 includes:

Converting LAB value of said real kraft paper into CMYK four color value to obtain CMYK four color value of said simulated kraft paper color, or

And converting the LAB value of the real kraft paper into a CMYK four-color value, and adjusting the CMKY four-color value to obtain the CMKY four-color value of the simulated kraft paper color.

Optionally, the step S5 comprises printing the digital manuscript on a matte digital paper, wherein the matte degree of the matte digital paper comprises a range of 1.5-3.5.

Optionally, the range of the LAB value of the priming white ink meeting the preset requirement comprises a range of 0-85, 0.71 and-0.35 respectively, wherein the range of L comprises 83.93+/-1.

Optionally, the density values of the CMYK four colors include 1.20±0.05, 1.21±0.05, 0.90±0.05, 1.21±0.05, respectively.

Alternatively, the LAB values of the real kraft paper comprise 55, 11, 24, respectively, and the CMYK four color values of the simulated kraft paper comprise 27.1, 44.8, 73.5, 11.3, respectively.

Optionally, the simulated kraft texture is adjustable.

The invention also provides a printing system for simulating kraft printing digital manuscript, comprising:

A printer configured to print the digital manuscript pattern on a real kraft paper to determine color feature data;

A target profile generation device configured to generate a target profile based on the color feature data, and

A digital printer connected to the target profile generation device and configured to perform the following operations:

Adding simulated kraft paper color and simulated kraft texture;

Determining CMYK four color values of the simulated kraft paper color, and

And printing the digital manuscript based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture to obtain the simulated kraft paper printing digital manuscript.

The present invention also provides a computer readable storage medium comprising computer executable instructions stored thereon which, when executed by a processor, implement a printing method as described above.

According to the printing method, a set of reference standard for kraft printing is defined by determining color characteristic data of digital manuscript patterns printed on real kraft paper. The color characteristic data is determined, the target characteristic file can be generated, a reference basis can be provided for printing the digital manuscript, the technical problems that kraft printing has randomness and is difficult to ensure the printing effect in the prior art are solved, and the color expression of printing the digital manuscript can be ensured. By adding simulated kraft paper color and simulated kraft texture, the fiber effect of the true kraft texture can be reproduced. By measuring LAB values of real kraft paper, CMYK four color values simulating kraft paper color can be determined. Based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture, the digital manuscript can be printed, the digital manuscript printed by the simulated kraft paper is obtained, the complex process and cost for printing on the real kraft paper by a printer are effectively saved, and the printing effect is ensured.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:

Fig. 1 illustrates a flow chart of a printing method of analog kraft printed digital manuscript, according to some embodiments of the invention.

Fig. 2 shows a flow chart of sub-steps of step S1 according to some embodiments of the invention.

Fig. 3a shows a schematic diagram of a first sample according to some embodiments of the invention.

Fig. 3b shows a schematic diagram of a second sample according to some embodiments of the invention.

Fig. 3c shows a schematic diagram of a third sample according to some embodiments of the invention.

Fig. 3d illustrates a schematic diagram of a digital manuscript simulating kraft printing, according to some embodiments of the invention.

Fig. 4a illustrates a schematic diagram of a brightness characteristic (i.e., a brightness optimization) of brightness variation within a preset brightness variation range according to some embodiments of the present invention.

Fig. 4b is a schematic diagram showing a chromaticity characteristic curve (i.e., chromaticity optimization curve) of chromaticity variation within a preset chromaticity variation range according to some embodiments of the invention.

Fig. 5 shows a flow chart of sub-step S17 according to some embodiments of the invention.

Fig. 6 illustrates a schematic of adding simulated kraft paper colors according to some embodiments of the invention.

Fig. 7 illustrates a schematic diagram of simulated kraft paper grain according to some embodiments of the invention.

Fig. 8 shows a flow chart of sub-step S4 according to some embodiments of the invention.

Fig. 9 shows a schematic diagram of determining CMYK four color values of a simulated kraft paper color according to some embodiments of the invention.

Fig. 10 illustrates a schematic diagram of a printing system that simulates kraft printing of digital manuscripts, according to some embodiments of the invention.

Detailed Description

Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may, for example, be fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, or communicable with each other, directly connected, indirectly connected via an intermediary, or communicate between two elements or interact between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The following provides many different embodiments or examples for implementing different structures of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, it being understood that the preferred embodiments described herein are for illustration and explanation of the present invention only, and are not intended to limit the present invention.

The invention provides a printing method for simulating kraft paper printing digital manuscript, which can provide standard basis for kraft paper printing, ensure visual effect and save complex printing flow and cost.

Fig. 1 illustrates a flow chart of a printing method 1 of analog kraft printed digital manuscript, according to some embodiments of the invention. As shown in FIG. 1, the printing method 1 includes steps S1 to S5, which are described in detail below.

Step S1, determining color characteristic data of patterns of the digital manuscript printed on real kraft paper. Based on this step, kraft printed color reference standards can be formulated. Fig. 2 shows a flow chart of sub-steps of step S1 according to some embodiments of the invention. As shown in FIG. 2, the step S1 includes substeps S11 to S17:

In the substep S11, the priming white ink is printed on the real kraft paper, so as to obtain LAB value and density value (density) of the priming white ink meeting the preset requirement. Specifically, the priming white ink can be printed on the real kraft paper for multiple times through a printer, and the LAB value and the density value of the priming white ink are measured for multiple times through a color difference meter, so that the priming white ink meeting the preset requirements is obtained, the visual effect of standard paper white is presented on the real kraft paper, and the color development stability is ensured. Lab values include three parameters, L (lightness), a (Red Green value) and b (Huang Lanzhi). Preferably, kraft paper with smooth surface, no reflection and no impurities is used to ensure accuracy and stability of the measurement results. Alternatively, the density value of the priming white ink may also be measured using a densitometer. In some embodiments, the L value of the priming white ink meeting the preset requirements may be in the range of 0 to 85.

Table 1 shows density values and LAB values of priming white ink S meeting preset requirements according to some embodiments of the present invention.

As shown in Table 1, the density value of the priming white ink S meeting the preset requirement is 0.23, and the Lab values are 83.93, 0.71 and-0.35, respectively. The L value of the priming white ink meeting the preset requirements may have a margin, for example 83.93±1. Note that the density values and LAB values of the priming white ink S shown in table 1 are merely exemplary illustrations, and do not limit the present invention.

TABLE 1

	Density of	L*	a*	b*
					S	0.23	83.93	0.71	-0.35
C	1.20	51.03	-25.09	-41.35
					M	1.21	45.60	55.94	3.29
Y	0.90	79.08	-6.03	66.65
					K	1.21	29.53	0.28	-1.29

And step S12, printing CMYK four colors on the priming white ink meeting the preset requirements to obtain density values of the CMYK four colors. The CMYK four colors include Cyan (Cyan, C), magenta (M), yellow (Yellow, Y), and black (black, K). Specifically, the printing machine may print the priming white ink meeting the preset requirements on the real kraft paper (that is, based on the LAB value and the density value of the priming white ink meeting the preset requirements obtained in the substep S11), print the CMYK four colors (four color separations) on the priming white ink meeting the preset requirements, measure the density values of the CMYK four colors by using a color difference meter, and obtain the density values of the CMYK four colors according to the measurement data displayed by the color difference meter. It should be appreciated that the color difference meter may also measure LAB values for the CMYK four colors. Note that, the real kraft paper used in the substep S12 has the same specification as the real kraft paper used in the substep S11.

Table 1 also shows density values and LAB values for CMYK four colors printed on priming white ink meeting preset requirements according to some embodiments of the invention. As shown in table 1, the density values of CMYK four colors are 1.20, 1.21, 0.90, 1.21, respectively. The LAB values for cyan C were 51.03, -25.09, -41.35, respectively. The LAB values for magenta M were 45.60, 55.94, 3.29, respectively. The LAB values for yellow Y were 79.08, -6.03, 66.65, respectively. The LAB values of black K are 29.53, 0.28, -1.29, respectively. The density values of CMYK four colors may have a margin, for example, the density values of CMYK four colors may be in the range of ±0.05. For example, the density values of the CMYK four colors may include 1.20±0.05, 1.21±0.05, 0.90±0.05, 1.21±0.05, respectively. The density values and LAB values of the CMYK four colors shown in table 1 are only exemplary, and do not limit the present invention.

And sub-steps S11-S12, defining a density standard of kraft printing, namely a density value of the priming white ink meeting preset requirements and a density value of CMYK four colors printed on the priming white ink. It should be appreciated that there may be some difference in visual effect exhibited by kraft paper treated by different processes, but that the density criteria for kraft paper printing may be defined by the above sub-steps S11-S12. Preferably, the specifications of the real kraft paper used in each step of the invention are the same to achieve consistency of the density standard, which is beneficial to finally exhibiting excellent visual effects. In a substep S13, a digital manuscript is printed on a white paper to obtain a first sample P1. Specifically, a digital printer may be used to print a digital manuscript on a standard white paper to obtain the first sample P1. Fig. 3a shows a schematic view of a first proof P1 according to some embodiments of the invention. The first sample P1 may be used as a reference sample for reference.

Step S14, printing the digital manuscript pattern on the real kraft paper based on the density value of the priming white ink meeting the preset requirement and the density value of the CMYK four colors printed on the priming white ink meeting the preset requirement to obtain a second sample sheet P2. Specifically, for example, the printer prints the digital manuscript pattern on the real kraft paper based on the user input priming white ink meeting the preset requirements and the density values of CMYK four colors printed thereon of 0.23, 1.20, 1.21, 0.90, 1.21, to obtain the second sample sheet P2. Fig. 3b shows a schematic diagram of a second sample sheet P2 according to some embodiments of the invention. It should be noted that, the specification of the real kraft paper used in the substeps S14 and S11 to S12 is the same.

In the substep S15, the second sample P2 is optimized based on the first sample P1, so as to obtain an optimized curve. The first sample P1 is obtained by printing a digital manuscript on standard white paper, the second sample P2 is obtained by printing a pattern of the digital manuscript on real kraft paper, and compared with the first sample P1 and the second sample P2, the cartoon of the second sample P2 has poor visual effect and needs to be optimized. The specific procedure for optimizing the second sample P2 is described below.

In some embodiments, optimizing the second sample P2 includes optimizing the brightness and/or chromaticity of the second sample P2 until the brightness variation is within a predetermined brightness variation range and/or the chromaticity variation is within a predetermined chromaticity variation range.

For example, the brightness of the second sample P2 may be optimized until the brightness variation is within the preset brightness variation range. Specifically, the CMY three primary colors are mixed (superimposed) in different proportions, and various gray tones from black to white are generated, whereby the brightness characteristic curve of the second sample sheet P2 can be determined. The brightness characteristic curve reflects the fluctuation condition of brightness, and the smaller the fluctuation is, the better the fluctuation is. Through cyclic calibration of the publication curve and visual evaluation (e.g., with reference to the first swatch P1), the brightness characteristic curve is optimized until the brightness variation is within the preset brightness variation range, resulting in brightness optimization curves (e.g., black line L1 and orange line L2 shown in fig. 4 a). When the brightness variation is within the preset brightness variation range, the brightness requirement of kraft printing is met.

Fig. 4a illustrates a schematic diagram of a brightness characteristic (i.e., a brightness optimization) of brightness variation within a preset brightness variation range according to some embodiments of the present invention. As shown in fig. 4a, the brightness characteristic may be a brightness versus dot gain (gray balance). The purple line L0 is the brightness baseline (i.e., line 0). The black line L1 is a variation curve of brightness of black K with a dot gain value. The orange line L2 is a variation curve of brightness of the three primary colors of CMY with the dot gain value. The brightness variation wΔl includes an average brightness variation Avg and a maximum brightness variation Max. The brightness variation wΔl is within a preset brightness variation range, including that the average brightness variation Avg is within a first preset range or that the maximum brightness variation Max is within a second preset range. Preferably, the brightness variation wΔl is within a preset brightness variation range and includes the average brightness variation Avg within a first preset range and the maximum brightness variation Max within a second preset range. The first preset range may be a range of 3 or less, that is, a range of 0 to 3. The second preset range may be a range of 5 or less, that is, a range of 0 to 5. In the embodiment of fig. 4a, the average brightness variation of black K is 1.16 and the maximum brightness variation is 2.40. The average brightness variation of the three primary colors of CMY is 0.55, and the maximum brightness variation is 1.23. However, the invention is not limited thereto. It can be understood that, although the black K can be obtained by mixing the three CMY inks in equal amounts, the overprint rate of the three CMY primary colors is difficult to reach 100%, and errors may occur due to insufficient purity of the three CMY inks, so that errors and costs can be reduced by directly using the black ink.

For another example, the chromaticity of the second sample P2 is optimized until the chromaticity variation is within the preset chromaticity variation range. Specifically, a chromaticity characteristic curve of the second sample may be determined, the chromaticity characteristic curve reflecting the fluctuation condition of chromaticity, the smaller the fluctuation the better. And (3) optimizing the chromaticity characteristic curve through cyclic calibration and publication curve and visual evaluation until the chromaticity variation is within a preset chromaticity variation range to obtain a chromaticity optimization curve (a green line L4 shown in fig. 4 b). And when the chromaticity variation is within the preset chromaticity variation range, the chromaticity requirement of kraft printing is met.

Fig. 4b is a schematic diagram showing a chromaticity characteristic curve (i.e., chromaticity optimization curve) of chromaticity variation within a preset chromaticity variation range according to some embodiments of the invention. As shown in fig. 4b, the chromaticity characteristic may be a chromaticity variation with the dot gain value. The purple line L0' is the chromaticity baseline (i.e., line 0). The pink line L3 is a chromaticity-dependent dot gain curve of the red-green value a. The blue line L5 is a chromaticity dependence of Huang Lanzhi b on the dot gain value. The green line L4 is a variation curve of chromaticity of CMY three primary colors with a dot gain value. The chromaticity variation wΔch includes an average chromaticity variation Avg and a maximum chromaticity variation Max. The chromaticity variation wΔch includes, within a preset chromaticity variation range, an average chromaticity variation within a first preset range or a maximum chromaticity variation within a second preset range. Preferably, the chromaticity variation wΔch is within the preset chromaticity variation range while including the average chromaticity variation Avg within the first preset range and the maximum chromaticity variation Max within the second preset range. The first preset range may be a range of 3 or less, that is, a range of 0 to 3. The second preset range may be a range of 5 or less, that is, a range of 0 to 5. In the embodiment of fig. 4b, the average chromaticity variation of the CMY three primary colors is 1.26 and the maximum chromaticity variation is 2.23. However, the invention is not limited thereto.

For another example, the brightness and the chromaticity of the second sample P2 are simultaneously optimized until the brightness variation wΔl is within the preset brightness variation range and the chromaticity variation wΔch is within the preset chromaticity variation range. For example, the average luminance variation is within a first preset range and the maximum luminance variation is within a second preset range, while the average chromaticity variation is within the first preset range and the maximum chromaticity variation is within the second preset range. When the brightness variation is within the preset brightness variation range and the chromaticity variation is within the preset chromaticity variation range, the brightness and chromaticity requirements of kraft printing are met at the same time.

And S16, printing a pattern of the digital manuscript on the real kraft paper based on the density values of the CMYK four colors, the density values of the priming white ink meeting the preset requirements and an optimization curve to obtain a third sample sheet P3. Specifically, based on density values of CMYK four colors of 1.20, 1.21, 0.90, 1.21, density value of priming white ink meeting preset requirements of 0.23, brightness optimization curve (black line L1 and orange line L2 shown in fig. 4 a) and chromaticity optimization curve (green line L4 shown in fig. 4 b), a pattern of digital manuscript is printed on real kraft paper, and a third sample sheet P3 is obtained. Fig. 3c shows a schematic view of a third sample sheet P3 according to some embodiments of the invention. As shown in fig. 3a to 3c, the third sample P3 significantly improves the visual effect presented by the second sample P2, and is close to the first sample P1, and the printing effect presented by the third sample P3 meets the requirements, so that the color expression is excellent.

In a substep S17, color feature data is obtained based on the third sample P3. Fig. 5 shows a flow chart of sub-step S17 according to some embodiments of the invention. As shown in FIG. 5, the substep S17 includes substeps S171 to S172. Sub-step S171, a TC1617 color chart of the third print swatch P3 is collected. In sub-step S172, color feature data, i.e. optimized LAB values, i.e. LAB values of the cartoon pattern, are obtained based on the TC1617 color table.

In some embodiments, the optimization data of some points in the third proof P3 are, for example:

the 25% CMY gray shade L is 66.2, the hue a is 2.0, and b is 0.4.

The 50% CMY gray shade L is 52.1, the hue a is 2.0, and b is 1.4.

The 25% CMY gray shade L is 39.6, the hue a is 1.6, and b is 1.1.

The 25% K gray L was 68.1.

50% K gray L was 54.8.

75% K gray L was 39.9.

It will be appreciated by those skilled in the art that any point of the third proof P3 will have a set of optimization data, and thus these optimization data are only exemplary and not limiting of the invention.

Through the substeps S13-S17, brightness and chromaticity standards of kraft paper printing are defined, standard basis is provided for kraft paper printing, and printing effect can be guaranteed.

And S2, generating a target characteristic file based on the color characteristic data. Specifically, the color feature data (optimized LAB value) may be imported into the target profile generating device, and the target profile may be generated from the color feature data obtained by the target profile generating device. That is, the target property file includes LAB values for the cartoon pattern of the digital manuscript. The object property file may be in the form of program code. The target characteristic file can be used later, the real kraft printing can be simulated through digital printing, the pattern effect is ensured, and meanwhile, the complex printing flow and cost can be saved. The following is a detailed description.

And S3, adding the simulated kraft paper color and the simulated kraft paper texture to reproduce the effect of the real kraft paper to the greatest extent. Fig. 6 illustrates a schematic of adding simulated kraft paper colors according to some embodiments of the invention. As shown in fig. 6, the digital printer may receive a user input instruction, select kraft (KRAFT PAPER) option, whereby a simulated kraft paper color may be added.

In some embodiments, the simulated kraft paper is adjustable in texture, including but not limited to thickness, shade, style of texture, meeting personalization requirements. Fig. 7 illustrates a schematic diagram of simulated kraft paper grain according to some embodiments of the invention. As shown in fig. 7, the left hand side illustrates a simulated kraft texture W1 that may be used for brown portions around the cartoon pattern (e.g., brown portion A1 illustrated in fig. 3 d), and the right hand side illustrates a simulated kraft texture W2 that may be used for light colored portions around the cartoon pattern (e.g., light colored portion A2 illustrated in fig. 3 d). The simulated kraft texture may be stored in memory or in an online database.

In step S4, CMYK four color values of the simulated kraft paper color are determined. Step S4 includes substeps S41-S42. Fig. 8 shows a flow chart of sub-step S4 according to some embodiments of the invention. Fig. 9 shows a schematic diagram of determining CMYK four color values of a simulated kraft paper color according to some embodiments of the invention. As shown in fig. 8 and 9, step S4 includes substeps S41 to S42.

In a substep S41, LAB values for the authentic kraft are determined. For example, LAB values of real kraft paper, such as 55, 11, 24 shown on the left side of fig. 9, can be measured by a color difference meter. The digital printer may receive a user input instruction to import the LAB value to the digital printer.

In a substep S42, CMYK four color values of the simulated kraft paper color are obtained based on LAB values of the real kraft paper. Specifically, the digital printer may convert the LAB values of the real kraft paper to CMYK four color values resulting in CMYK four color values simulating kraft paper colors, such as 27.1, 44.8, 73.5, 11.3 shown on the right side of fig. 9. Or after the LAB value of the real kraft paper is converted into the CMYK four color value, the CMKY four color value can be adjusted to obtain the CMKY four color value of the simulated kraft paper color.

In step S5, the digital manuscript is printed based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture, and the simulated kraft paper printing digital manuscript P4 is obtained. More specifically, the target profile generating device is in communication connection with the digital printer, and the target profile generating device sends the target profile to the digital printer, and the digital printer prints the digital manuscript on the matte digital paper based on the LAB values of the cartoon patterns in the target profile, the CMYK values of the simulated kraft paper colors and the simulated kraft textures to obtain the simulated kraft printed digital manuscript P4. Fig. 3d illustrates a schematic diagram of a digital manuscript P4 simulating kraft printing in accordance with some embodiments of the invention. As can be seen by comparing fig. 3c and 3d, the resulting digital manuscript P4 simulating kraft paper almost perfectly reproduces the visual effect exhibited by the pattern P3 printed on the real kraft paper. Preferably, the matte degree of the matte digital paper can be 1.5-3.5, but the invention is not limited thereto.

According to the printing method, a set of reference standard for kraft printing is defined by determining color characteristic data of digital manuscript patterns printed on real kraft paper. The color characteristic data is determined, the target characteristic file can be generated, a reference basis can be provided for printing the digital manuscript, the technical problems that kraft printing has randomness and is difficult to ensure the printing effect in the prior art are solved, and the color expression of printing the digital manuscript can be ensured. By adding simulated kraft paper color and simulated kraft texture, the fiber effect of the true kraft texture can be reproduced. By measuring LAB values of real kraft paper, CMYK four color values simulating kraft paper color can be determined. Based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture, the digital manuscript can be printed, the digital manuscript printed by the simulated kraft paper is obtained, the complex process and cost for printing on the real kraft paper by a printer are effectively saved, and the printing effect is ensured.

The invention also provides a printing system for simulating kraft printing digital manuscripts. Fig. 10 illustrates a schematic diagram of a printing system 20 that simulates kraft printing of digital manuscripts, according to some embodiments of the invention. As shown in fig. 10, the printing system 20 includes a printer 210, a target profile generating device 220, and a digital printer 230. Printer 210 may print the digital manuscript pattern on a real kraft paper to determine color characterization data. The target profile generation means 220 may generate the target profile based on the color feature data. The digital printer 230 is connected to the target profile generating means 220 and may perform an operation of adding the simulated kraft paper color and the simulated kraft paper texture (i.e., step S3 described above). The CMYK four color values of the simulated kraft paper color are determined (i.e., step S4 described above). Printing the digital manuscript based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture to obtain a digital manuscript simulating kraft paper printing (i.e. the step S5).

In some embodiments, printing system 20 of the present invention may also include a test instrument, such as a color difference meter, to measure LAB values and density values.

The printing system 20 of the present invention may implement any of the steps, sub-steps, and any embodiment or combination thereof of the printing methods described above.

In some embodiments, the printer 210, the target profile generation device 230, and the digital printer 230 include a memory (not shown) and a processor (not shown).

In some embodiments, the memory may include random access memory (randomaccess memory, RAM) or non-volatile memory (nonvolatile memory). Further, the memory may include at least one of phase-change memory (phase-change random access memory, PRAM), static random access memory (static random access memory, SRAM), dynamic random access memory (dynamic random access memory, DRAM), read-only memory (ROM), and electrically erasable programmable read-only memory (ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY, EEPROM).

In some embodiments, the Processor may include a central processing unit (Central Processing Unit, CPU), a micro-processing unit (Micro Control Unit, MCU), and may also include other general purpose processors, digital signal processors (DIGITAL SIGNAL processors, DSPs), application Specific Integrated Circuits (ASICs), off-the-shelf Programmable gate arrays (Field-Programmable GATE ARRAY, FPGA), complex Programmable logic devices (Complex Programmable logic device, CPLD) or other Programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like, and peripheral circuits thereof.

The printing system of the invention can execute the printing method, and defines a set of reference standards for kraft printing by determining the color characteristic data of the digital manuscript pattern printed on the real kraft paper. The color characteristic data is determined, the target characteristic file can be generated, a reference basis can be provided for printing the digital manuscript, the technical problems that kraft printing has randomness and is difficult to ensure the printing effect in the prior art are solved, and the color expression of printing the digital manuscript can be ensured. By adding simulated kraft paper color and simulated kraft texture, the fiber effect of the true kraft texture can be reproduced. By measuring LAB values of real kraft paper, CMYK four color values simulating kraft paper color can be determined. Based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture, the digital manuscript can be printed, the digital manuscript printed by the simulated kraft paper is obtained, the complex process and cost for printing on the real kraft paper by a printer are effectively saved, and the printing effect is ensured.

The present invention also provides a computer readable storage medium comprising computer executable instructions stored thereon which, when executed by a processor, implement a printing method as described above.

The present invention may take the form of a computer program product embodied on one or more storage media having program code embodied therein. Computer-usable storage media include both permanent and non-permanent, removable and non-removable media, and information storage may be implemented by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, PRAM, SRAM, DRAM, other types of RAM, ROM, EEPROM, flash memory or other memory technology, compact disk-read only memory (CD-ROM), digital versatile disk (digital video disc, DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by the computing device.

It is noted that the present specification provides method operations as examples or schematics, but may include more or fewer operations based on conventional or non-inventive labor. The order of operations recited in the embodiments is merely one way of performing the operations and does not represent a unique order of execution. When a system or apparatus product in practice is executed, it may be executed sequentially or in parallel according to the method shown in the embodiment or the flowchart.

It should be noted that the above-mentioned embodiments are merely preferred embodiments of the present invention, and the present invention is not limited thereto, but may be modified or substituted for some of the technical features thereof by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (18)

1. A method of printing a digital manuscript simulating kraft printing, comprising:

S1, determining color characteristic data of patterns of the digital manuscript printed on real kraft paper;

S2, generating a target characteristic file based on the color characteristic data;

s3, adding simulated kraft paper color and simulated kraft paper texture;

S4, determining CMYK four color values of the simulated kraft paper color, and

And S5, printing the digital manuscript based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture to obtain the simulated kraft paper printing digital manuscript.

2. The printing method according to claim 1, wherein the step S1 comprises the sub-steps of:

S11, printing priming white ink on real kraft paper to obtain LAB value and density value of the priming white ink meeting preset requirements;

s12, printing CMYK four colors on the priming white ink meeting the preset requirements to obtain density values of the CMYK four colors;

S13, printing the digital manuscript on white paper to obtain a first sample;

S14, printing the pattern of the digital manuscript on real kraft paper based on the density values of the CMYK four colors and the density value of the priming white ink meeting the preset requirements to obtain a second sample sheet;

S15, optimizing the second sample based on the first sample to obtain an optimized curve;

S16, printing the pattern of the digital manuscript on real kraft paper based on the density values of the CMYK four colors, the density values of the priming white ink meeting the preset requirements and the optimized curve to obtain a third sample sheet, and

And S17, obtaining the color characteristic data based on the third sample.

3. The printing method according to claim 2, wherein the optimizing the second sample includes optimizing the lightness and/or chroma of the second sample until the lightness variation is within a preset lightness variation range and/or the chroma variation is within a preset chroma variation range.

4. A printing method according to claim 3, wherein the step of optimizing the brightness of the second swatch comprises:

Determining a brightness characteristic curve of the second sample;

And optimizing the brightness characteristic curve until the brightness variation is within the preset brightness variation range.

5. The printing method of claim 4 wherein the lightness characteristic comprises a lightness-to-dot gain value variation, wherein the lightness variation comprises an average lightness variation and a maximum lightness variation, wherein the lightness variation is within the preset lightness variation range comprises the average lightness variation being within a first preset range and/or the maximum lightness variation being within a second preset range.

6. A printing method according to claim 3, wherein the step of optimizing the chromaticity of the second swatch comprises:

determining a chromaticity characteristic curve of the second sample;

And optimizing the chromaticity characteristic curve until the chromaticity variation is within the preset chromaticity variation range.

7. The printing method according to claim 6, wherein the chromaticity characteristic includes a chromaticity variation with a dot gain value, wherein the chromaticity variation includes an average chromaticity variation and a maximum chromaticity variation, and wherein the chromaticity variation is within the preset chromaticity variation range includes the average chromaticity variation being within a first preset range and/or the maximum chromaticity variation being within a second preset range.

8. The printing method according to claim 5 or 7, wherein the first preset range includes a range of 3 or less, and the second preset range includes a range of 5 or less.

9. A printing method according to claim 2 or 3, characterized in that the sub-step S17 comprises the sub-steps of:

s171, collecting a TC1617 color chart of the third printing sample;

And S172, obtaining the color characteristic data based on the TC1617 color table, wherein the color characteristic data comprises LAB values.

10. The printing method according to any one of claims 1 to 7, wherein the step S4 comprises the sub-steps of:

S41, determining LAB values of the real kraft paper;

S42, obtaining CMYK four color values of the simulated kraft paper based on the LAB value of the real kraft paper.

11. The printing method according to claim 10, wherein the substep S42 comprises:

Converting LAB value of said real kraft paper into CMYK four color value to obtain CMYK four color value of said simulated kraft paper color, or

And converting the LAB value of the real kraft paper into a CMYK four-color value, and adjusting the CMKY four-color value to obtain the CMKY four-color value of the simulated kraft paper color.

12. The printing method according to any one of claims 1 to 7, wherein the step S5 includes printing the digital manuscript on a matte digital paper, and the matte degree of the matte digital paper includes a range of 1.5 to 3.5.

13. The printing method according to claim 2, wherein the LAB values of the priming white ink meeting the preset requirements respectively comprise a range of 0 to 85, 0.71, -0.35, wherein the range of L comprises 83.93±1.

14. The printing method according to claim 2, wherein the density values of the CMYK four colors include 1.20±0.05, 1.21±0.05, 0.90±0.05, 1.21±0.05, respectively.

15. The printing method according to any one of claims 1 to 7, wherein LAB values of the real kraft paper comprise 55, 11, 24, respectively, and CMYK four color values of the simulated kraft paper color comprise 27.1, 44.8, 73.5, 11.3, respectively.

16. The printing method of any one of claims 1-7 wherein the simulated kraft paper texture is adjustable.

17. A printing system for simulating kraft printing of digital manuscripts, comprising:

A printer configured to print the digital manuscript pattern on a real kraft paper to determine color feature data;

A target profile generation device configured to generate a target profile based on the color feature data, and

A digital printer connected to the target profile generation device and configured to perform the steps of:

Adding simulated kraft paper color and simulated kraft texture;

Determining CMYK four color values of the simulated kraft paper color, and

And printing the digital manuscript based on the target characteristic file, the CMYK four color values of the simulated kraft paper color and the simulated kraft paper texture to obtain the simulated kraft paper printing digital manuscript.

18. A computer readable storage medium comprising computer executable instructions stored thereon, which when executed by a processor, implement the printing method of any of claims 1-17.