Laser printing chromatography determination method, system and equipment, medium and product

Abstract

The invention discloses a laser printing chromatography determination method, system and device, a medium and a product, and relates to the technical field of printing. The method comprises the steps that the chromatic value of a target color of a laser printed matter is obtained; determining the color difference between the target color and the adjacent chromatographic color under the condition that the lightness L * and the saturation C * ab are not changed, and converting the color difference into a hue angle difference; respectively adjusting the lightness L * and the saturation C * ab under the condition that the hue angle is not changed according to the chromatic value of the center color of the chromatographic page to obtain all chromatographic colors; converting chromatic values CIEL * a * b * of all chromatographic colors corresponding to the center color of the chromatographic page into printing CMYK values under the absolute reproduction intention condition by using the ICC characteristic file; determining all chromatographic pages of the target color according to the printing CMYK value; and printing, outputting and binding all chromatography pages under a standard process condition to form the laser printing chromatography. The laser printing chromatogram provided by the invention can fully reflect the color generation characteristic of the laser paper-based printed product.

Description

Technical Field

[0001] The present application relates to the field of printing technology, and in particular to a method, system, device, medium and product for determining a laser printing color spectrum. Background Art

[0002] Cigarette packaging printed materials based on laser paper are the main product types currently produced by cigarette packaging printing companies. This type of product has a gorgeous bright rainbow effect, or has an obvious light column transformation effect when observed at different angles (directions). The special color rendering effect of this printing material will bring a series of practical difficulties to color measurement and ink color matching during printing proofing.

[0003] To achieve the same color as the standard sample or standard sample CIEL provided by the customer * a * b * The color value is consistent. At present, the method commonly used by printing companies in the process of printing proofing is to use the commercial standard color matching manual or Pantone color card on the market to select the amount of CMYK ink. This selection is mostly done by employees visually or relying on experience to select the appropriate CMYK value to adjust the color of the corresponding area on the digital image to achieve visual consistency with the original (this process mainly compares the screen display color and the printing color based on laser paper).

[0004] At present, most color matching manuals on the market are based on ordinary printing substrates (such as offset paper, coated paper or white cardboard, etc.). The design of the CMYK color spectrum is usually based on coated paper and matte paper, and the printing method and printing process parameters are explained on this basis. Different CMYK ink volumes are marked on the color spectrum to provide color comparison, search and color matching references for printing technicians. Considering that the material of the substrate will affect the color appearance, the Pantone color spectrum is divided into different types according to its printing substrate (or application scenario), such as: plastic color card, TSX polyester color card, TN nylon color card, TCX color card, TPG color card, which is widely used in graphic design, packaging printing, textile printing and dyeing, interior decoration and other fields.

[0005] When printing the outer packaging of different products, such as tobacco, alcohol, cosmetics or electronic products, enterprise personnel usually use CMYK color spectrum or Pantone spot color as a reference. The main problems are: 1) When reproducing the CMYK ink dosage recommended by the above color spectrum on the laser paper base, its color appearance (visual perception effect of the human eye) will be quite different from the color of the corresponding ink volume on the color spectrum. 2) The screen display color and the standard sample original color (based on laser paper) are reproduced in different color rendering methods. This visual consistency does not really indicate that the CMYK ink volume has reached the best, and it often deviates far from the true value (standard sample value). How to adjust the printing color in real time according to the color spectrum to achieve the consistency between the screen color and the actual printed color, there is currently no corresponding color matching color card as a reference. The above problems bring certain difficulties to the staff's pre-press production and printing proofing ink color selection, which will lead to repeated pre-press and printing proofing color adjustment and a high product scrap rate.

[0006] When the same amount of ink is printed on a laser paper base to make a color card, different locations will have different CIEL when the color is measured on the surface. * a * b * Chromaticity value, it is difficult to quantitatively characterize the chromaticity value of the color card. At present, there is no similar laser color card on the market for printing color comparison and color ink adjustment. If a color card based on laser paper can be produced, a printing color spectrum that can fully reflect the color characteristics of laser paper-based printed products will significantly improve the accuracy of ink selection in the laser printing proofing process, shorten the printing proofing time, improve work efficiency, reduce production costs and scrap rates, and provide guarantees for the company's product quality improvement and profit growth, which has practical application value. Summary of the invention

[0007] The purpose of this application is to provide a method, system, equipment, medium and product for determining a laser printing color spectrum, which can fully reflect the printing color spectrum of the color rendering characteristics of laser paper-based printed products, thereby significantly improving the accuracy of ink selection in the laser printing proofing process, shortening the printing proofing time, improving work efficiency, and reducing production costs and scrap rates.

[0008] To achieve the above objectives, this application provides the following solutions:

[0009] In a first aspect, the present application provides a method for determining a laser printing chromatogram, the method comprising:

[0010] Obtaining an ICC characteristic file corresponding to the printed output under standard process conditions of laser printing; the standard process conditions include: plate making and printing;

[0011] Get the chromaticity value CIEL of the target color of the laser print * 0a* 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0, ab h * 0,ab ;

[0012] Determine the target color at lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ;

[0013] According to the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium hue angle h * 0,ab and hue angle difference Δh * ab Determine 5 hue angles centered on the target color and compare them with the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium lightness L * 0 and Saturation C * 0,ab Combined into 5 chromaticity values ​​CIEL * a * b * ; 5 said chromaticity values ​​CIEL * a * b * As the center color of 5 color spectrum pages;

[0014] According to the chromaticity value of the center color of each color spectrum page CIEL * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab, get all the color spectrum corresponding to the current color spectrum page;

[0015] Use the ICC profile to convert the chromaticity values ​​of all chromatographic colors corresponding to the center color of each chromatographic page into CIEL * a * b * Convert to printing CMYK values ​​under absolute rendering intent conditions;

[0016] Determine all color spectrum pages of the target color according to the printed CMYK value of each color spectrum page;

[0017] All color spectrum pages of the target color are printed, output and bound under standard process conditions to form a laser printed color spectrum.

[0018] Optionally, the number of sampled colors of the ICC characteristic file is greater than or equal to 900; and the average color difference of the ICC characteristic file is less than 0.5ΔE * ab ; ΔE * ab For color difference.

[0019] Optionally, the chromaticity value CIEL of the target color of the laser printed product is obtained. * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab , specifically including:

[0020] When the laser paper base of the laser printed matter is rainbow beam laser paper or platinum beam laser paper, the size of each sampled color is greater than or equal to 5cm×1cm; when measuring the sampled color, an integrating sphere spectrophotometer is used to measure greater than or equal to 7 measurement points within a complete beam cycle in the cross-sectional direction of the beam; and the sampling interval×collection point data ≥1 complete beam cycle;

[0021] When the laser paper base of the laser printed product is a plain laser paper, the shape of each sampled color element is a square, and the side length of the square is greater than or equal to 1 cm; when measuring the sampled color, an integrating sphere spectrophotometer is used to sample at different positions for more than 3 times, and the average value of the measurement results is taken as the chromaticity value CIEL at the element. * 0a * 0b * 0.

[0022] Optionally, the target color is determined at a lightness L * and saturation C * abThe hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab , including:

[0023] Using the formula Determine the hue difference ΔH * ab ;

[0024] Among them, ΔE a * b is the color difference, ΔL * For brightness difference, is the saturation difference, saturation are the brightness of the target color and the adjacent color respectively, is the chromaticity index of the target color, is the chromaticity index of the adjacent color, Δa * , Δb * are the chromaticity index differences between the target color and the adjacent color, subscript 1 represents the chromaticity value of the target color, and subscript 2 represents the chromaticity value of the adjacent color.

[0025] Optionally, the chromaticity value CIEL of the central color of each color spectrum page * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum colors corresponding to the current color spectrum page, including:

[0026] The central color of each color spectrum page is adjacent to each other in the up, down, left and right directions, and the color difference is formed by increasing the brightness, decreasing the brightness, decreasing the saturation and increasing the saturation respectively, and the color difference formed is 0.5 times, 1.0 times, 1.5 times, and even n times the color difference threshold of the central color; the changed CIEL * a * b * The chromaticity value and the chromaticity value of the center color together constitute the chromaticity values ​​of all colors of the current color spectrum page, and form all colors of the current color spectrum page.

[0027] Optionally, the printing, outputting and binding of all color spectrum pages of the target color under standard process conditions to form a laser printed color spectrum specifically includes:

[0028] Print and bind all color spectrum pages of target color under standard process conditions;

[0029] The printing materials, printing inks and printing conditions are described on the first page of the binding to form a laser printing color spectrum.

[0030] In a second aspect, the present application provides a laser printing chromatogram determination system, the laser printing chromatogram determination system comprising:

[0031] An ICC characteristic file determination module is used to obtain an ICC characteristic file corresponding to the printed output under standard process conditions of laser printing; the standard process conditions include: plate making and printing;

[0032] Chromaticity value acquisition module, used to obtain the chromaticity value CIEL of the target color of the laser print * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab ;

[0033] The hue difference determination module is used to determine the target color in lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ;

[0034] Color spectrum page determination module, used to determine the CIEL color value * 0C * 0,ab h * 0,ab Medium hue angle h * 0,ab and hue angle difference Δh * ab Determine 5 hue angles centered on the target color and compare them with the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium lightness L * 0 and Saturation C* 0,ab Combined into 5 chromaticity values ​​CIEL * a * b * ; 5 said chromaticity values ​​CIEL * a * b * As the center color of 5 color spectrum pages;

[0035] The color determination module of the color spectrum page is used to determine the chromaticity value CIEL of the center color of each color spectrum page. * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum corresponding to the current color spectrum page;

[0036] Printing CMYK value conversion module, used to convert the chromaticity values ​​of all chromatographic colors corresponding to the center color of each chromatographic page into CIEL using the ICC characteristic file * a * b * Convert to printing CMYK values ​​under absolute rendering intent conditions;

[0037] A module for determining all color spectrum pages of a target color, used for determining all color spectrum pages of a target color according to the printed CMYK value of each color spectrum page;

[0038] The laser printing color spectrum determination module is used to print, output and bind all color spectrum pages of the target color under standard process conditions to form a laser printing color spectrum.

[0039] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the laser printing chromatogram determination method.

[0040] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and the computer program, when executed by a processor, implements the laser printing chromatogram determination method.

[0041] In a fifth aspect, the present application provides a computer program product, including a computer program, which implements the laser printing color spectrum determination method when executed by a processor.

[0042] According to the specific embodiments provided in this application, this application has the following technical effects:

[0043] This application provides a method, system, device, medium and product for determining laser printing color spectrum. According to the chromaticity value of the target color sample of each cigarette package laser printing product produced by the enterprise, each target color and a plurality of colors with different differences in hue, brightness and saturation are formed. The target color and the adjacent color spectrum form the acceptable color difference threshold of the human eye, and the CIEL of the corresponding color is marked. * a * b * Chromaticity values ​​and standard printing CMYK values ​​are used for reasonable color selection and adjustment of the dot size design of the corresponding colors of different CMYK ink channels in the pre-press and print proofing processes. This application mainly uses laser paper as the substrate in the surface packaging printing industry. When printing the outer packaging of cigarettes, alcohol, cosmetics and electronic products, there is no reference color spectrum for color reference and comparison, and it is impossible to perform real-time color calibration design of screen colors and print colors. A reference and guidance method for CMYK ink volume control can be provided for pre-press staff and printing production personnel of printing companies. The laser printing color spectrum of this application can fully reflect the color rendering characteristics of laser paper-based printed products, thereby significantly improving the accuracy of ink volume selection in the laser printing proofing process, shortening the printing proofing time, improving work efficiency, and reducing production costs and scrap rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 This is a schematic flow chart of a method for determining a laser printing color spectrum in one embodiment of the present application;

[0046] Figure 2 A partial color diagram of a sampling color code for producing and printing an International Color Consortium (ICC) profile used in the embodiments;

[0047] Figure 3 A schematic diagram of the color gamut obtained by printing and outputting the rainbow beam laser paper used in the embodiment and the color coordinate distribution of two target colors on the color gamut body;

[0048] Figure 4 For the examples used, *ab No change, L * , C * ab When the color difference of adjacent colors is changed to make the color difference threshold acceptable to the human eye, the color arrangement of the surrounding colors is formed. * a * b * Schematic diagram of chromaticity value selection;

[0049] Figure 5 Maintaining the hue angle h for the target color 1 in the embodiment * 0,ab Unchanged color diagram of the color spectrum page;

[0050] Figure 6 The hue angle of the target color 1 in the embodiment is (h * 0,ab +2Δh * ab ) color diagram of the color spectrum page;

[0051] Figure 7 Maintaining the hue angle h for target color 2 in the embodiment * 0,ab Unchanged color diagram of the color spectrum page;

[0052] Figure 8 The hue angle of the target color 2 in the embodiment is (h * 0,ab +2Δh * ab ) color diagram of the color spectrum page;

[0053] Fig. 9 Maintaining the hue angle h for the target color 1 in the embodiment * 0,ab Schematic diagram of the colorful effect of the unchanged color spectrum page print;

[0054] Fig.10 Maintaining the hue angle h for target color 2 in the embodiment * 0,ab Schematic diagram of the colorful effect of the unchanged color spectrum page print;

[0055] Fig.11 For the examples used, * ab No change, L * , C * ab Changed color spectrum page colors CIEL * a * b * Schematic diagram of the color value and CMYK value mark page. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0058] In an exemplary embodiment, Figure 1 As shown, a method for determining a laser printing color spectrum is provided, and the method includes the following S101 to S108. Wherein:

[0059] S101, obtain the ICC characteristic file corresponding to the printed output under the standard process conditions of laser printing; the standard process conditions include: plate making and printing; the number of sampled colors in the process of making the ICC characteristic file shall not be less than 900, and the color measurement shall use a spectrophotometer with integrating sphere geometry conditions. After the sampled color is output, it shall be measured after the color is stable, and each sampled color shall be averaged based on several measured values ​​within the laser beam cycle. In addition, the number of color blocks and the ICC file making software used shall ensure that the accuracy of the ICC characteristic file is an average color difference of less than 0.5ΔE * ab .

[0060] The production process of the ICC characteristic file for rainbow beam laser printing output is as follows:

[0061] CMYK is a color mode for color printing. Among them, C stands for cyan, M stands for magenta, Y stands for yellow, and K stands for key plate (mainly used to deepen the dark part). For CMYK overprinting, the C, M, Y, K dot values ​​represent the amount of ink printed for the color ink, and the change of their values ​​corresponds to the change of printing color. Therefore, CMYK and its corresponding printing color CIEL * a * b * There is a certain correspondence between the values. The numerical correlation between the two is called the color characterization of the printing process. The International Color Consortium (ICC) has stipulated the standard color mode and file format for recording the numerical relationship. The characterization data file formed is called the ICC characteristic file. The ICC characteristic file is used to complete the conversion of CMYK values ​​to CIEL * a * b* Calculation of numerical and reverse processes.

[0062] The creation of ICC profiles requires the use of professional software and hardware tools. In this embodiment, the software is X-Rite's i1Profiler (to create ICC profiles), and the hardware is the colorimeter X-Rite Ci64 (to measure the chromaticity of sampled colors for printed output).

[0063] To establish the relationship between two color data in the ICC characteristic file, first obtain several experimental samples of known color values ​​to form a mathematical relationship. The above process is called sampling. For output devices such as printing and printing, professional software will provide a variety of different numbers of sampled color sets for different needs. For example, for CMYK devices such as printing, the number of colors in the sampled color set can be as small as a few hundred or as high as a few thousand. The more samples there are, the more accurate the mathematical relationship established. In this embodiment, 2033 sample colors are selected.

[0064] For conventional substrate printing and other output situations, each set of CMYK values ​​forms a square color block with a certain side length (which can accommodate the light hole size of the colorimeter), which can represent a printed color. i1Profiler also only provides this kind of sampling color image formation method. However, for the printing of light column laser paper with a periodic structure, the color of the printed output color corresponding to a set of CMYK values ​​changes within a light column cycle, so it is necessary to use the color of a complete light column cycle to represent it. To this end, this embodiment changes the square of the sampled color into a long strip shape (the length direction is perpendicular to the light column direction of the light column laser paper) with a length of 56mm and a width of 11mm in response to the printing sampling needs of light column laser paper. Its length includes a complete light column cycle, and the width meets the requirements of the color measurement aperture. A partial color digital image of 2033 sampled CMYK colors, such as Figure 2 shown.

[0065] Afterwards, the sampled CMYK image is color separated, plate-made and printed according to the normal printing process to obtain the printed output colors of each sampled color on the rainbow beam laser paper. After the printed sampled color is stable, an integrating sphere spectrophotometer X-Rite Ci64 is used to measure 7 points uniformly in the length direction (cross section of the beam) of each printed color bar and ensure that the sampling interval × the data of the collection point should be ≥ 1 complete beam cycle. CIEL of 7 measurement points for each color bar * a * b * The average value is taken as the chromaticity value of the printed color.

[0066] Finally, the 2033 color bars CIEL measured * a * b *The chromaticity value is input into the ICC Profile creation software i1Profiler, and the ICC profile creation is completed according to its instructions.

[0067] In order to characterize the color conversion accuracy of the ICC profile, the 2033 sampled values ​​CMYK are converted to CIEL under the "absolute rendering intent" parameter through the ICC profile. * a * b * Value (representing the printed color predicted by the ICC profile) and the actual measured sample printed color chromaticity value CIEL * a * b * A one-to-one color difference calculation is performed to characterize the accuracy of the color conversion relationship in the ICC profile to predict the color. After calculation, the ΔE of the 2033 sampled colors * ab The average color difference is 0.11, indicating that the ICC profile has sufficiently high color conversion accuracy.

[0068] S102, obtaining the chromaticity value CIEL of the target color of the laser printed product * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab ;

[0069] S102 specifically includes:

[0070] When the laser paper base of the laser printed matter is rainbow beam laser paper or platinum beam laser paper, the size of each sampled color is greater than or equal to 5cm×1cm; when measuring the sampled color, an integrating sphere spectrophotometer is used to measure greater than or equal to 7 measurement points within a complete beam cycle in the cross-sectional direction of the beam; and the sampling interval×collection point data ≥1 complete beam cycle;

[0071] When the laser paper base of the laser printed product is a plain laser paper, the shape of each sampled color element is a square, and the side length of the square is greater than or equal to 1 cm; when measuring the sampled color, an integrating sphere spectrophotometer is used to sample at different positions for more than 3 times, and the average value of the measurement results is taken as the chromaticity value CIEL at the element. * 0a * 0b * 0.

[0072] In a specific embodiment, two target colors are selected: target color 1 (red) and target color 2 (light green). The CIEL values ​​of the target colors under the conditions of D65 standard light source and CIE1964 standard observer function are as follows: * 0a * 0b * 0 value, and the corresponding CIEL * 0C * 0, ab h * 0,ab Value (where L * 0 is called brightness, C * 0,ab It is called saturation, h * 0,ab The hue angle is shown in Table 1.

[0073] Table 1

[0074] <![CDATA[L * 0]]> <![CDATA[a * 0]]> <![CDATA[b * 0]]> <![CDATA[C * 0，ab ]]> <![CDATA[h * 0，ab (°)]]> Target color 1 46.14 45.47 25.88 52.31 29.64 Target color 2 70.82 -12.91 11.13 17.05 139.23

[0075] like Figure 3 As shown, the two target colors are within the color gamut (the range of colors that can be formed) output by the printing method used and the standard process conditions, and colors with slight differences in their brightness and saturation can still be within the color gamut, which means that the printing output is capable of printing these two colors and colors with slight differences in their brightness and saturation.

[0076] S103, determine the target color in lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ;

[0077] S103 specifically includes:

[0078] Using the formula Determine the hue difference ΔH * ab ;

[0079] in, is the color difference, ΔL * For brightness difference, is the saturation difference, saturation are the brightness of the target color and the adjacent color respectively, is the chromaticity index of the target color, is the chromaticity index of the adjacent color, Δa * , Δb * are the chromaticity index differences between the target color and the adjacent color, subscript 1 represents the chromaticity value of the target color, and subscript 2 represents the chromaticity value of the adjacent color.

[0080] When C * 0,ab When the value is less than 10.0, it is considered as achromatic, ΔH * ab =0.3; C * 0,ab When the value is ≥10.0, it is considered to be colorful, ΔH * ab =0.8.

[0081] Different hue attributes are red, yellow, yellow-green and other different colors, and C * 0,ab Achromatic colors with values ​​less than 10.0; CIEL corresponding to different target colors * 0a * 0b * 0 value, by its corresponding ΔH * ab The value is calculated to get its value in a * b * The hue angle Δh of the plane deviating from the target color * ab .

[0082] If the brightness of two colors L * and saturation C * ab The same, then ΔL * =0, ΔC * ab =0, then ΔH * ab =ΔE * ab , that is, the hue difference is equal to the color difference. That is:

[0083] ΔH * ab =ΔE * ab,T ;

[0084] For the above two target colors, due to their chroma C * 0,ab If the values ​​are all greater than 10, it is considered to be colorful, ΔH * ab Take 0.8.

[0085] ΔH * ab Convert to the corresponding Δh *ab ,Right now:

[0086]

[0087] From: a = C * 0,ab ×cosh * ab , b=C * 0,ab× sinh * ab ,have to:

[0088]

[0089] Let the hue difference threshold ΔH T =ΔH * ab ,therefore,

[0090]

[0091] Then we get the hue angle And its corresponding hue angle difference Δh * ab ;formula The same brightness and chroma as the target color, and the difference is a hue difference threshold ΔH * ab,T Hue angle of color The solution relationship is After that, the corresponding color chromaticity value can be obtained as L * 0C * 0, ab h * 1,ab (Corresponding to L * 0a * 1b * 1 chromaticity value).

[0092] S104, based on chromaticity value CIEL * 0C * 0ab h * 0ab Medium hue angle h * 0ab and hue angle difference Δh * ab Determine 5 hue angles centered on the target color and compare them with the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium lightness L *0 and Saturation C * 0,ab Combined into 5 chromaticity values ​​CIEL * a * b * ; 5 said chromaticity values ​​CIEL * a * b * As the center color of 5 color spectrum pages;

[0093] Among them, the five hue angles centered on the target color are: h * 0,ab -2×Δh * ab 、h * 0,ab -Δh * ab 、h * 0,ab 、h * 0,ab +Δh * ab and h * 0,ab +2×Δh * ab , and as shown in Table 2.

[0094] Table 2

[0095] <![CDATA[h * 0,ab -2Δh * ab ]]> <![CDATA[h * 0,ab -Δh * ab ]]> <![CDATA[h * 0,ab ]]> <![CDATA[h * 0,ab +Δh * ab ]]> <![CDATA[h * 0,ab +2Δh * ab ]]> Target color 1 27.89 28.76 29.64 30.52 31.39 Target color 2 133.85 136.54 139.23 141.92 144.61

[0096] The 5 hue angles are respectively related to L * 0C * 0,ab Combination, corresponding to the formation of 5 CIEL * a * b * Chromaticity values, the center colors of the five color spectrum pages, C * ab 、h * ab with a * 、b * The relationship is as follows:

[0097]

[0098] The 5 color centers of CIEL * C * ab h * ab Corresponding CIEL * a * b * The chromaticity values ​​are shown in Table 3.

[0099] Table 3

[0100]

[0101] S105, according to the chromaticity value CIEL of the center color of each color spectrum page * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum corresponding to the current color spectrum page;

[0102] S105 specifically includes:

[0103] The central color of each color spectrum page is adjacent to each other in the up, down, left and right directions, and the color difference is formed by increasing the brightness, decreasing the brightness, decreasing the saturation and increasing the saturation respectively, and the color difference formed is 0.5 times, 1.0 times, 1.5 times, and even n times the color difference threshold of the central color; the changed CIEL * a * b * The chromaticity value and the chromaticity value of the center color together constitute the chromaticity values ​​of all colors of the current color spectrum page, and form all colors of the current color spectrum page.

[0104] For target color 1, its hue angle h * 0,ab =29.64°, keep the hue angle unchanged, take it as the central color, and increase and decrease its L around the colors respectively. * and C * ab The color difference thresholds are 0.5, 1.0, and 1.5 times the color difference between the changed color and the original center target color. The surrounding color arrangement is as follows: Figure 4 As shown ( Figure 4 In both * C * ab h * ab LCh for short is a color spectrum page with the same hue angle. In this color spectrum page, if the color difference between the center color and the color of the surrounding shadow background is within a perceptible color difference range, it is a qualified product. If the color difference between the surrounding colors and the center color is greater than a perceptible color difference, it can be easily judged as a substandard product.

[0105] In this embodiment, ΔE * ab The color difference threshold is 2.5.

[0106] Set all colors of this color spectrum page to CIEL * C * ab h * ab The corresponding CIEL value is calculated * a * b * value, forming L * a * b * Chromatographic image of the mode.

[0107] Hue angle h of target color 1 * 0,ab =29.64° and hue angle h * 0,ab +2Δh * ab =31.39° Figure 4 The same color role spectrum page L of the arrangement shown * a * b * The model images are as follows Figure 5 and Figure 6 shown.

[0108] Hue angle h of target color 2 * 0,ab =139.23° and h * 0,ab +2Δh * ab =144.61° Figure 4 The same color role spectrum page L of the arrangement shown * a * b * The mode images are as follows: Figure 7 and Figure 8 shown.

[0109] S106, using the ICC characteristic file, convert the chromaticity values ​​of all chromatographic colors corresponding to the center color of each chromatographic page into CIEL * a * b * Convert to printing CMYK values ​​under absolute rendering intent conditions;

[0110] right Figures 5 to 8 CIEL shown * a * b *The numerical color spectrum page image is converted into a CMYK image under the absolute rendering intent parameters through the ICC characteristic file, and the color spectrum page is subsequently output according to the normal plate making and printing process.

[0111] Due to the rainbow light beam effect of the rainbow light beam laser paper substrate, Figure 5 , Figure 6 CIEL shown * a * b * The color spectrum will show Fig. 9 and Fig.10 The colorful effect shown.

[0112] S107, determining all color spectrum pages of the target color according to the printed CMYK values ​​of each color spectrum page;

[0113] S108, printing, outputting and binding all the color spectrum pages of the target color under standard process conditions to form a laser printed color spectrum.

[0114] S108 specifically includes:

[0115] Print and bind all color spectrum pages of target color under standard process conditions;

[0116] The printing materials, printing inks and printing conditions are described on the first page of the binding to form a laser printing color spectrum.

[0117] against Figures 5 to 8 After the color spectrum pages shown are printed out, all colors on each page are measured and the measured CIEL * a * b * The colorimetric values ​​and CMYK values ​​used for output are marked in Fig.11 The corresponding position on the sample page shown is printed out and bound to the corresponding chromatogram page.

[0118] The printed color spectrum is only of reference value for printing color matching and printing proofing under the same printing conditions. The printed color spectrum needs to measure the CIEL of each color. * a * b * The chromaticity value, together with its CMYK value, is filled in the color numerical annotation page, which is printed out and bound after the corresponding color spectrum page.

[0119] Based on the same inventive concept, the embodiment of the present application also provides a laser printing chromatogram determination system for implementing the laser printing chromatogram determination method involved above. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above method, so the specific limitations of one or more laser printing chromatogram determination system embodiments provided below can refer to the limitations of the laser printing chromatogram determination method above, and will not be repeated here.

[0120] In an exemplary embodiment, a laser printing color spectrum determination system is provided, comprising:

[0121] An ICC characteristic file determination module is used to obtain an ICC characteristic file corresponding to the printed output under standard process conditions of laser printing; the standard process conditions include: plate making and printing;

[0122] Chromaticity value acquisition module, used to obtain the chromaticity value CIEL of the target color of the laser print * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab ;

[0123] The hue difference determination module is used to determine the target color in lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ;

[0124] Color spectrum page determination module, used to determine the CIEL color value * 0C * 0,ab h * 0,ab Medium hue angle h * 0,ab and hue angle difference Δh * ab Determine 5 hue angles centered on the target color and compare them with the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium lightness L * 0 and Saturation C * 0,abCombined into 5 chromaticity values ​​CIEL * a * b * ; 5 said chromaticity values ​​CIEL * a * b * As the center color of 5 color spectrum pages;

[0125] The color determination module of the color spectrum page is used to determine the chromaticity value CIEL of the center color of each color spectrum page. * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum corresponding to the current color spectrum page;

[0126] Printing CMYK value conversion module, used to convert the chromaticity values ​​of all chromatographic colors corresponding to the center color of each chromatographic page into CIEL using the ICC characteristic file * a * b * Convert to printing CMYK values ​​under absolute rendering intent conditions;

[0127] A module for determining all color spectrum pages of a target color, used for determining all color spectrum pages of a target color according to the printed CMYK value of each color spectrum page;

[0128] The laser printing color spectrum determination module is used to print, output and bind all color spectrum pages of the target color under standard process conditions to form a laser printing color spectrum.

[0129] In an exemplary embodiment, a computer device is provided, which may be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (I / O for short) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a laser printing chromatography determination method is implemented.

[0130] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0131] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0132] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0133] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0134] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0135] In this application, all actions to obtain signals, information or data are carried out in compliance with the relevant data protection laws and policies of the country where they are located and with the authorization given by the owner of the corresponding device.

[0136] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for determining a laser printed color spectrum, characterized in that: The laser printing chromatogram determination method comprises: Obtaining an ICC characteristic file corresponding to the printed output under standard process conditions of laser printing; the standard process conditions include: plate making and printing; Get the chromaticity value CIEL of the target color of the laser print * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab ; Determine the target color at lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ; According to the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium hue angle h * 0,ab and hue angle difference Δh * ab Determine 5 hue angles centered on the target color and compare them with the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium lightness L * 0 and Saturation C * 0,ab Combined into 5 chromaticity values ​​CIEL * a * b * ; 5 said chromaticity values ​​CIEL * a * b * As the center color of 5 color spectrum pages; According to the chromaticity value of the center color of each color spectrum page CIEL * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum corresponding to the current color spectrum page; Use the ICC profile to convert the chromaticity values ​​of all chromatographic colors corresponding to the center color of each chromatographic page into CIEL * a * b * Convert to printing CMYK values ​​under absolute rendering intent conditions; Determine all color spectrum pages of the target color according to the printed CMYK value of each color spectrum page; All color spectrum pages of the target color are printed, output and bound under standard process conditions to form a laser printed color spectrum.

2. The method for determining laser printed chromatograms according to claim 1, characterized in that: The number of sampled colors of the ICC characteristic file is greater than or equal to 900; the average color difference of the ICC characteristic file is less than 0.5ΔE * ab ; ΔE * ab For color difference.

3. The method for determining laser printed chromatograms according to claim 1, characterized in that: The chromaticity value CIEL of the target color of the laser printed product is obtained * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab , specifically including: When the laser paper base of the laser printed matter is rainbow beam laser paper or platinum beam laser paper, the size of each sampled color is greater than or equal to 5cm×1cm; when measuring the sampled color, an integrating sphere spectrophotometer is used to measure greater than or equal to 7 measurement points within a complete beam cycle in the cross-sectional direction of the beam; and the sampling interval×collection point data ≥1 complete beam cycle; When the laser paper base of the laser printed product is a plain laser paper, the shape of each sampled color element is a square, and the side length of the square is greater than or equal to 1 cm; when measuring the sampled color, an integrating sphere spectrophotometer is used to sample at different positions for more than 3 times, and the average value of the measurement results is taken as the chromaticity value CIEL at the element. * 0a * 0b * 0.

4. The method for determining laser printed chromatograms according to claim 1, characterized in that: Determine the target color at lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab , specifically including: Using the formula Determine the hue difference ΔH * ab ; in, is the color difference, ΔL * For brightness difference, is the saturation difference, saturation are the brightness of the target color and the adjacent color respectively, is the chromaticity index of the target color, is the chromaticity index of adjacent colors, Δa * , Δb * are the chromaticity index differences between the target color and the adjacent color, subscript 1 represents the chromaticity value of the target color, and subscript 2 represents the chromaticity value of the adjacent color.

5. The method for determining laser printed chromatograms according to claim 1, characterized in that: The chromaticity value CIEL of the central color of each color spectrum page * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum colors corresponding to the current color spectrum page, including: The central color of each color spectrum page is adjacent to each other in the up, down, left and right directions, and the color difference is formed by increasing the brightness, decreasing the brightness, decreasing the saturation and increasing the saturation respectively, and the color difference formed is 0.5 times, 1.0 times, 1.5 times, and even n times the color difference threshold of the central color; the changed CIEL * a * b * The chromaticity value and the chromaticity value of the center color together constitute the chromaticity values ​​of all colors of the current color spectrum page, and form all colors of the current color spectrum page.

6. The method for determining laser printed chromatograms according to claim 1, characterized in that: The printing, outputting and binding of all color spectrum pages of the target color under standard process conditions to form a laser printed color spectrum specifically includes: Print and bind all color spectrum pages of target color under standard process conditions; The printing materials, printing inks and printing conditions are described on the first page of the binding to form a laser printing color spectrum.

7. A laser printing color spectrum determination system, characterized in that: The laser printing chromatogram determination system comprises: An ICC characteristic file determination module is used to obtain an ICC characteristic file corresponding to the printed output under standard process conditions of laser printing; the standard process conditions include: plate making and printing; Chromaticity value acquisition module, used to obtain the chromaticity value CIEL of the target color of the laser print * 0a * 0b * 0 and the corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab ; The hue difference determination module is used to determine the target color in lightness L * and saturation C * ab The hue difference ΔH between the adjacent chromatographic colors under the same condition * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ; Color spectrum page determination module, used to determine the CIEL color value * 0C * 0,ab h * 0,ab Medium hue angle h * 0,ab and hue angle difference Δh * ab Determine 5 hue angles centered on the target color and compare them with the chromaticity value CIEL * 0C * 0,ab h * 0,ab Medium lightness L * 0 and Saturation C * 0,ab Combined into 5 chromaticity values ​​CIEL * a * b * ; 5 said chromaticity values ​​CIEL * a * b * As the center color of 5 color spectrum pages; The color determination module of the color spectrum page is used to determine the chromaticity value CIEL of the center color of each color spectrum page. * a * b * And the corresponding chromaticity value CIEL * C * ab h * ab , at the hue angle h * ab Under the condition of no change, adjust the brightness L * and saturation C * ab , get all the color spectrum corresponding to the current color spectrum page; Printing CMYK value conversion module, used to convert the chromaticity values ​​of all chromatographic colors corresponding to the center color of each chromatographic page into CIEL using the ICC characteristic file * a * b * Convert to printing CMYK values ​​under absolute rendering intent conditions; A module for determining all color spectrum pages of a target color, used for determining all color spectrum pages of a target color according to the printed CMYK value of each color spectrum page; The laser printing color spectrum determination module is used to print, output and bind all color spectrum pages of the target color under standard process conditions to form a laser printing color spectrum.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the laser printing chromatogram determination method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the laser printing chromatogram determination method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the laser printing chromatogram determination method according to any one of claims 1 to 6 is implemented.

Images