A method, system, device, medium, and product for laser printing chromatography determination

Abstract

The application discloses a laser printing color spectrum determination method, system, device, medium and product, relates to the technical field of printing, and comprises the following steps: acquiring a chroma value of a target color of a laser printing product; determining a hue difference of the target color with an adjacent color spectrum color under the condition that a lightness L * and a saturation C * ab is unchanged; converting the hue difference into a hue angle difference; adjusting the lightness L * and the saturation C * ab of the target color under the condition that the hue angle is unchanged according to the chroma value of the center color of the color spectrum page; obtaining all color spectrum colors; converting the chroma values CIEL * a * b * of all color spectrum colors corresponding to the center color of the color spectrum page into printing CMYK values under the condition of absolute reproduction intention; determining all color spectrum pages of the target color according to the printing CMYK values; printing and binding all color spectrum pages under standard process conditions to form a laser printing color spectrum. The laser printing color spectrum can fully reflect the color rendering characteristics of the laser paper-based printing product.

Description

TECHNICAL FIELD

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

[0002] The cigarette package printed product with laser paper as the base material is the main product type produced by the current cigarette package printing enterprise. This kind of product has a beautiful bright rainbow effect, or has obvious bright and dark light column transformation effect when observed from different angles (directions). The special color effect of this printing material will bring a series of practical difficulties to color measurement, ink color matching and other aspects in the printing proofing process.

[0003] In order to realize the consistency with the standard sample color or standard sample CIEL * a * b * At present, the method commonly used by printing enterprises in the ink color matching in the printing proofing process is to use the commercial standard color matching manual or Pantone color card to select the ink amount of CMYK ink. This selection is mostly that the employees select the appropriate CMYK value to adjust the color of the corresponding area on the image digital manuscript by visual observation or experience, so as to achieve visual consistency with the original manuscript (this process mainly compares the screen display color and the printing color with laser paper as the base material).

[0004] At present, the color matching manual on the market mostly takes ordinary printing printing materials (such as offset paper, art paper or white card paper, etc.) as the base, usually designs the printing CMYK color spectrum, mainly takes the art paper and matte paper base, and on this basis, explains the printing method, printing process parameters, etc., and the color spectrum is marked with different CMYK ink amount, which provides color comparison, searching and color matching reference for printing technicians. Considering that the material of the printing material will affect the appearance of the color, the Pantone color spectrum is divided into different types according to its printing base (or application scene), such as plastic color card, TSX polyester color card, TN nylon color card, TCX color card and TPG color card, which has a wide application in the fields of graphic design, packaging printing, textile printing and dyeing, interior decoration, etc.

[0005] When enterprise personnel perform color printing on the outer packaging of different products, such as tobacco and alcohol, cosmetics, or electronic products, CMYK color spectrum colors or Pantone spot colors are usually used as references. The main problems are as follows: 1) When the CMYK ink usage amount recommended by the color spectrum is reproduced on a laser paper base, the color appearance (visual perception effect of the human eye) will be quite different from the color corresponding to the ink amount on the color spectrum. 2) The screen display color and the original color of the standard sample (on a laser paper base) are reproduced in different color rendering modes. Such visual consistency cannot truly indicate that the CMYK ink amount has reached the best value, and often deviates from the true value (standard sample value) by a large margin. Currently, there is no corresponding color matching color card as a reference for how to perform real-time regulation of printing colors according to color spectrum colors to achieve consistency between screen colors and actual printed colors. The above problems bring certain difficulties to the color selection of pre-press production and printing proofing ink regulation, and will lead to repeated pre-press and printing proofing color regulation and a high product scrap rate.

[0006] When the same ink amount is printed on a laser paper base to perform color card production, different positions will have different CIEL * a * b * chroma values, and it is difficult to quantitatively characterize the chroma values of the color card. Currently, there is no similar laser color card on the market for printing color comparison and color ink amount regulation. If a color card based on a laser paper base can be produced, a printing color spectrum that fully reflects the color rendering characteristics of laser paper base printed products can be obtained, which will significantly improve the accuracy of ink amount selection in the laser printing proofing process, shorten the printing proofing time, improve the work efficiency, reduce the production cost and the scrap rate, provide guarantee for the product quality improvement and profit growth of enterprises, and has practical application value. SUMMARY

[0007] The purpose of the present application is to provide a laser printing color spectrum determination method, system, device, medium and product, which can fully reflect the color rendering characteristics of laser paper base printed products, thereby significantly improving the accuracy of ink amount selection in the laser printing proofing process, shortening the printing proofing time, improving the work efficiency, and reducing the production cost and the scrap rate.

[0008] To achieve the above purpose, the present application provides the following solutions:

[0009] In a first aspect, the present application provides a laser printing color spectrum determination method, which comprises the following steps:

[0010] acquiring an ICC profile corresponding to a printing output under standard process conditions of laser printing; the standard process conditions comprise plate making and printing;

[0011] acquiring the chroma value CIEL * 0a* 0b * 0and the corresponding chromaticity value CIEL * 0C * 0, ab h * 0,ab ;

[0012] determining the target color in terms of lightness L * and saturation C * ab a hue difference ΔH * ab ; and converting the hue difference ΔH * ab to a hue angle difference Δh * ab ;

[0013] according to the chromaticity value CIEL * 0C * 0,ab h * 0,ab the middle hue angle h * 0,ab and the hue angle difference Δh * ab determining five hue angles centered on the target color, each combined with the chromaticity value CIEL * 0C * 0,ab h * 0,ab in terms of lightness L * 0and saturation C * 0,ab to five chromaticity values CIEL * a * b * ; the five chromaticity values CIEL * a * b * serving as the center colors of five color spectrum pages;

[0014] according to the chromaticity value CIEL * a * b * of each color spectrum page center color and the corresponding chromaticity value CIEL * C * ab h * ab adjusting the lightness L * ab and the saturation C * * ab ​obtaining all the colorimetric values CIEL

[0015] obtaining all the colorimetric values CIEL * a * b * converting into printed CMYK values under absolute reproduction intention;

[0016] determining all the color pages of the target color according to the printed CMYK values of each color page;

[0017] printing and binding all the color pages of the target color under standard process conditions to form the laser printing color spectrum.

[0018] Optionally, the number of sampling colors of the ICC profile is greater than or equal to 900; the average color difference of the ICC profile is less than 0.5ΔE * ab ; ΔE * ab is the color difference.

[0019] Optionally, the colorimetric values CIEL * 0a * 0b * 0and the corresponding colorimetric values CIEL * 0C * 0,ab h * 0,ab , and specifically comprising:

[0020] When the laser paper base of the laser printing product is a rainbow light column laser paper or a platinum light column laser paper as the printing paper base, the size of each sampling color is greater than or equal to 5cm×1cm; when measuring the sampling color, an integrating sphere spectrophotometer is used to measure more than 7 measurement points in 1 complete light column period in the cross direction of the light column; and the sampling interval×the number of collected points≥1 complete light column period.

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

[0022] Optionally, the target color is determined to be in the lightness L * and the saturation C * abThe hue difference ΔH between the adjacent color spectrum color * ab The hue difference ΔH between the adjacent color spectrum color * ab The hue difference ΔH between the adjacent color spectrum color * ab The hue difference ΔH between the adjacent color spectrum color

[0023] The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color * ab The hue difference ΔH between the adjacent color spectrum color

[0024] The hue difference ΔH between the adjacent color spectrum color a * b The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color

[0025] The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color ab The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color ab The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color ab The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color ab The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color

[0026] The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color * The hue difference ΔH between the adjacent color spectrum color The hue difference ΔH between the adjacent color spectrum color

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

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

[0029] The first page of the bound book describes the printing substrate, printing ink, and printing conditions, forming a laser printing color spectrum.

[0030] Secondly, this application provides a laser printing chromatographic determination system, the laser printing chromatographic determination system comprising:

[0031] The ICC profile determination module is used to obtain the corresponding ICC profile for the printing output under the standard process conditions of laser printing; the standard process conditions include: plate making and printing;

[0032] The colorimetric value acquisition module is used to obtain the colorimetric value (CIEL) of the target color in laser printing. * 0a * 0b * 0 and its corresponding chromaticity value CIEL * 0C * 0,ab h * 0,ab ;

[0033] The hue difference determination module is used to determine the target color at a lightness level of L. * and saturation C * ab The hue difference ΔH between the color and adjacent chromatic colors under the condition that it remains unchanged * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ;

[0034] The colorimetric page determination module is used to determine the colorimetric page based on CIEL values. * 0C * 0,ab h * 0,ab Midcolor phase angle h * 0,ab and hue angle difference Δh * ab Determine five hue angles centered on the target color, and each angle is correlated with the chromaticity value CIEL. * 0C * 0,ab h * 0,ab Medium brightness L * 0 and saturation C* 0,ab The combination is 5 colorimetric values CIEL * a * b * ; 5 said colorimetric values CIEL * a * b * as the center color of the 5 color spectrum pages;

[0035] A color spectrum page color determination module is configured to determine the colorimetric values CIEL * a * b * of the center color of each color spectrum page according to the colorimetric values CIEL * C * ab h * ab , respectively adjust the lightness L * and the saturation C ab * without changing the hue h * ab to obtain all color spectrum colors corresponding to the current color spectrum page;

[0036] A printing CMYK value conversion module is configured to convert the colorimetric values CIEL * a * b * of all color spectrum colors corresponding to the center color of each color spectrum page into printing CMYK values under the absolute reproduction intention condition by using an ICC profile;

[0037] A target color all color spectrum page determination module is configured to determine a target color all color spectrum page according to the printing CMYK values of each color spectrum page;

[0038] A laser printing color spectrum determination module is configured to perform printing output and binding on the target color all color spectrum page under a standard process condition 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 color spectrum determination method.

[0040] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program executable by a processor to implement the laser printing color spectrum determination method.

[0041] In a fifth aspect, the present application provides a computer program product, which comprises a computer program executable by a processor to implement the laser printing color spectrum determination method.

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

[0043] The present application provides a laser printing color spectrum determination method, system, device, medium and product. For the colorimetric value of the target color sample of each cigarette package laser printing product produced by an enterprise, a plurality of colors different from the target color in hue, lightness and saturation are formed. The target color and the adjacent color spectrum color form an acceptable color difference threshold of the human eye as the design goal, and the CIEL * a * b * The colorimetric value and the standard printing CMYK value are marked for reasonable selection of color and adjustment of CMYK different ink channel corresponding color dot size design in pre-press and printing proofing process. The present application uses laser paper as the printing material in the main packaging printing industry. When printing the outer packaging of cigarettes, wine, cosmetics and electronic products, there is no reference color spectrum for color reference and comparison, and it is impossible to perform real-time screen color and printing color adjustment design. The present application can provide a reference and guidance method for CMYK ink amount control for pre-press workers and printing production personnel of printing enterprises. The laser printing color spectrum of the present application can fully reflect the color rendering characteristics of laser paper printing, thereby significantly improving the accuracy of ink amount selection in the laser printing proofing process, shortening the printing proofing time, improving the work efficiency, reducing the production cost and the waste rate. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0045] Figure 1 The figure is a flow chart of a laser printing color spectrum determination method in an embodiment of the present application;

[0046] Figure 2 The figure is a color sample part color schematic diagram for manufacturing the International Color Consortium (ICC) profile used in the embodiment;

[0047] Figure 3 The figure is a color gamut and color coordinate distribution schematic diagram of two target colors on the color gamut body obtained by printing output of the rainbow light column laser paper used in the embodiment;

[0048] Figure 4 The figure is a color sample part color schematic diagram for manufacturing the International Color Consortium (ICC) profile used in the embodiment; *ab unchanged, L * unchanged, C * ab changed, CIEL * a * b * Colorimetric value value diagram;

[0049] Figure 5 unchanged, CIEL * 0,ab unchanged, CIEL

[0050] Figure 6 unchanged, CIEL * 0,ab + 2Δh * ab unchanged, CIEL

[0051] Figure 7 unchanged, CIEL * 0,ab unchanged, CIEL

[0052] Figure 8 unchanged, CIEL * 0,ab + 2Δh * ab unchanged, CIEL

[0053] Figure 9 unchanged, CIEL * 0,ab unchanged, CIEL

[0054] Figure 10 unchanged, CIEL * 0,ab unchanged, CIEL

[0055] Figure 11 unchanged, CIEL * ab unchanged, L * unchanged, C * ab changed, CIEL * a * b * Colorimetric value and CMYK value marking page diagram. DETAILED DESCRIPTION

[0056] Clearly and completely, the technical solutions in the embodiments of the present application will be described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0057] The above purposes, features and advantages of the present application will be more apparent and understandable. The present application will be further described in detail in combination with the drawings and specific embodiments.

[0058] In one exemplary embodiment, as shown in Figure 1 A laser printing color spectrum determination method is provided, which comprises the following S101 to S108. Among them:

[0059] S101, under the standard process conditions of laser printing, the ICC profile corresponding to the printing output is obtained; the standard process conditions include: plate making and printing; the number of sampling colors in the process of making the ICC profile should not be less than 900, the measurement of color should use the spectrophotometer with the integrating sphere geometry condition, the sampling color output should be measured after the color is stable, and each sampling color should be averaged according to several measurement values in the laser beam period. In addition, the number of color blocks and the ICC file making software used should ensure that the accuracy of the ICC profile is less than 0.5ΔE * ab .

[0060] Among them, the process of making the ICC profile of the rainbow beam laser printing output is:

[0061] CMYK is the color mode of color printing. Among them, C represents cyan, M represents magenta, Y represents yellow, and K represents black (Key Plate, mainly used to deepen dark part). For CMYK superimposed mode, C, M, Y, K dot value represents the printing ink amount of the color ink, the change of the value corresponds to the change of the printing color, then there is a certain corresponding relationship between CMYK and its corresponding printing color CIEL * a * b * Value. The numerical relationship between the two is called color characterization of the printing process. ICC (International Color Consortium) International Color Association specifies the standard color mode and file format to record the numerical relationship, and the resulting characterization data file is called ICC profile. The ICC profile is used to complete the conversion from CMYK value to CIEL * a * b* Numerical values and calculations of the inverse process.

[0062] The creation of ICC profile requires professional software and hardware tools. In this embodiment, the software is i1Profiler (realizing the creation of ICC profile) of X-Rite, and the hardware is color measuring instrument X-Rite Ci64 (colorimetric measurement of printed output sampling color).

[0063] The establishment of the relationship between the two kinds of color data in ICC profile is to obtain a plurality of experimental samples of known color values first, and then form a mathematical relationship, which is called sampling. For printing, printing and other output devices, professional software provides a plurality of different numbers of sampling color sets for different needs, such as for printing and other CMYK devices, the number of sampling color sets can be as small as several hundred, and as large as several thousand. The more the number of samples, the more accurate the mathematical relationship. In this embodiment, 2033 sample colors are selected.

[0064] For the printing, printing and other output of the conventional substrate, each group of CMYK values forms a square color block with a certain side length (which can accommodate the light aperture size of the color measuring instrument), which can represent a printed color, and i1Profiler only provides this kind of sampling color image forming method. However, for the printing of the light column laser paper with periodic structure, the printed output color corresponding to a group of CMYK values is changing in a light column period, so a complete light column period of color needs to be represented. Therefore, for the printing sampling needs of the light column laser paper, the square shape of the sampling color is changed to 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. The length contains a complete light column period, and the width meets the requirements of color measurement aperture. Part of the digital images of the 2033 sampling CMYK colors are shown in FIG. 1. Figure 2

[0065] Then, according to the normal printing process, color separation, plate making and printing of the sampling CMYK image are carried out to obtain the printed output color of each sampling color on the rainbow light column laser paper. After the printing of the sampling color is stable, the integral sphere spectrophotometer X-Rite Ci64 is used to measure 7 points uniformly in the length direction of each color bar (light column cross section) and ensure that the sampling interval x the number of collected points should be ≥1 complete light column period. The CIEL * a * b * mean value of each color bar is taken as the colorimetric value of the printed color.

[0066] Finally, the measured CIEL * a * b * ​The chroma values are input to the ICC Profile making software i1Profiler, and the making of the ICC profile is completed according to the instructions.

[0067] In order to characterize the color conversion accuracy of the ICC profile, 2033 sample values CMYK are converted to CIEL * a * b * values (representing the predicted printing colors of the ICC profile) under the "absolute reproduction intent" parameter via the ICC profile, and compared with the actually measured sample printing color chroma values CIEL * a * b * One-to-one color difference calculation is performed to characterize the accuracy of the ICC profile in predicting the chroma of the color conversion relationship. After calculation, the ΔE * ab The average color difference is 0.11, indicating that the ICC profile has a high enough color conversion accuracy.

[0068] S102, obtaining the chroma values CIEL * 0a * 0b * 0 of the target colors of the laser printing product and the corresponding chroma values CIEL * 0C * 0,ab h * 0,ab ;

[0069] S102 specifically includes:

[0070] When the laser paper base of the laser printing product is a rainbow light column laser paper or a platinum light column laser paper as the printing paper base, the size of each sample color is greater than or equal to 5 cm x 1 cm; when measuring the sample color, an integrating sphere spectrophotometer is used to measure more than 7 measurement points in 1 complete light column period in the cross direction of the light column; and the sampling interval x the number of collected points is greater than or equal to 1 complete light column period.

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

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

[0073] Table 1

[0074] L * 0]]> a * 0]]> b * 0]]> C * 0，ab ]] 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 and standard process conditions, and colors that are slightly different from them in terms of brightness and saturation can still be within this color gamut. This means that the printing output is capable of printing these two colors and colors with slightly different brightness and saturation.

[0076] S103, Determine the target color at a lightness level of L. * and saturation C * ab The hue difference ΔH between the color and adjacent chromatic colors under the condition that it remains unchanged * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab ;

[0077] S103 specifically includes:

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

[0079] in, Due to color difference, ΔL * Due to poor brightness, For saturation difference, saturation These are the brightness levels of the target color and its adjacent colors, respectively. The chromaticity index of the target color. The chromaticity index of adjacent colors, Δa * Δb * These are the chromaticity index differences between the target color and adjacent colors, respectively. 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 <10.0, it is considered non-color, ΔH * ab =0.3; C * 0,ab A value ≥ 10.0 is considered to be colored, ΔH * ab =0.8.

[0081] Different hue attributes result in different colors such as red, yellow, and yellowish-green, and are all C. * 0,ab Non-color values ​​< 10.0; CIEL corresponding to different target colors * 0a * 0b * The value of 0 is determined by its corresponding ΔH. * ab The value is calculated to obtain its value in a * b * The hue angle Δh of the plane deviating from the target color * ab .

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

[0083] ΔH * ab =ΔE * ab,T ;

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

[0085] ΔH * ab Convert to the corresponding Δh *ab i.e.

[0086]

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

[0088]

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

[0090]

[0091] Further, we get the hue angle and its corresponding hue angle difference Δh * ab ; formula The hue angle of the color which is equal in lightness and chroma to the target color and differs by a hue difference threshold ΔH * ab,T After solving , we can get the corresponding color chroma value L * 0C * 0, ab h * 1,ab (corresponding to L * 0a * 1b * 1 chroma value).

[0092] S104, according to the chroma value CIEL * 0C * 0ab h * 0ab the hue angle h * 0ab and the hue angle difference Δh * ab Determine 5 hue angles centered on the target color, and all are equal in lightness and chroma to the chroma value CIEL * 0C * 0,ab h * 0,ab L * ​0 and the saturation C * 0,ab The combination of 5 chrominance values CIEL * a * b * ; 5 said chrominance values CIEL * a * b * as the center color of 5 color spectrum pages;

[0093] Wherein, 5 hue angles centered on the target color are respectively: h * 0,ab -2 x Ah * ab , h * 0,ab - Ah * ab , h * 0,ab , h * 0,ab + Ah * ab and h * 0,ab + 2 x Ah * ab , as shown in Table 2.

[0094] Table 2

[0095] h * 0,ab -2Δh * ab ]]> h * 0,ab -Δh * ab ]]> h * 0,ab ]]> h * 0,ab +Δh * ab ]]> 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] 5 hue angles respectively with L * 0C * 0,ab combination, corresponding to form 5 CIEL * a * b * chrominance values, respectively 5 color spectrum pages as the center color, C * ab , h * ab and a * , b * relationship as follows:

[0097]

[0098] The CIEL * C * ab h * ab corresponding CIEL * a * b * chrominance values are shown in Table 3, respectively.

[0099] Table 3

[0100]

[0101] S105, according to the chromaticity value CIEL of the central color of each chromatogram page * a * b * and the corresponding chromaticity value CIEL * C * ab h * ab , when the hue angle h * ab remains unchanged, adjust the lightness L * and saturation C * ab respectively, to obtain all the chromatogram colors corresponding to the current chromatogram page;

[0102] S105 specifically includes:

[0103] Adjacent to the central color of each chromatogram page successively in the up, down, left, and right directions, respectively increase the lightness, decrease the lightness, decrease the saturation, and increase the saturation to form color differences, and the formed color differences form color difference thresholds of 0.5 times, 1.0 times, 1.5 times, up to n times with the central color; the changed CIEL * a * b * chromaticity values and the chromaticity values of the central color together constitute the chromaticity values of all the colors of the current chromatogram page, and form all the colors of the current chromatogram page. [[ID=​​​​​​​​​​​​​​​​​​​​​​​

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

[0106] This color spectrum page contains all colors CIEL * C * ab h * ab Calculate the corresponding CIEL value * a * b * Value, forming L * a * b * Chromatographic images of the pattern.

[0107] Hue angle h of target color 1 * 0,ab =29.64° and hue angle h * 0,ab +2Δh * ab =31.39° corresponding Figure 4 The same hue character page L is arranged as shown. * a * b * The pattern images are as follows: Figure 5 and Figure 6 As shown.

[0108] Hue angle h of target color 2 * 0,ab =139.23° and h * 0,ab +2Δh * ab =144.61° corresponds to Figure 4 The same hue character page L is arranged as shown. * a * b * The pattern images are respectively as follows Figure 7 and Figure 8 As shown.

[0109] S106, using the ICC profile, extract the chromaticity values ​​(CIEL) of all colors corresponding to the center color of each color spectrum page. * a * b * Converted to printable CMYK values ​​under the condition of absolute reproduction intention;

[0110] right Figures 5-8 CIEL shown * a * b *The numerical colorimetric page image is converted into a CMYK image using ICC profiles under absolute reproduction intent parameters. The subsequent output of the colorimetric page is completed according to the normal plate-making and printing process.

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

[0112] S107, determine the target color for all color pages based on the printed CMYK values ​​of each color page;

[0113] S108, under standard process conditions, prints and binds all pages of the target color spectrum to form a laser-printed color spectrum.

[0114] S108 specifically includes:

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

[0116] The first page of the bound book describes the printing substrate, printing ink, and printing conditions, forming a laser printing color spectrum.

[0117] against Figures 5-8 After the color spectrum pages shown are printed, measure all colors on each page and record the measured CIEL values. * a * b * The chromaticity values ​​and the CMYK values ​​used for output are marked in Figure 11 Print out the corresponding position in the shown pattern page and bind it after the corresponding chromatogram page.

[0118] Printed color charts are only relevant for color matching and proofing under the same printing conditions. After printing, the CIEL (chromatic ellipse intensity) of each color needs to be measured. * a * b * The chromaticity values, along with their CMYK values, should be entered into the color value label page, printed out, and bound after the corresponding color chart page.

[0119] Based on the same inventive concept, the embodiments of the present application also provide a laser printing color spectrum determination system for implementing the above-mentioned laser printing color spectrum determination method. The system provides a solution to the problem similar to the implementation solution described in the above-mentioned method, and therefore the specific limitations in one or more laser printing color spectrum determination system embodiments provided below can refer to the limitations of the laser printing color spectrum determination method described above, which will not be repeated here.

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

[0121] An ICC profile determination module is configured to obtain an ICC profile corresponding to a printing output under standard process conditions of laser printing, wherein the standard process conditions comprise plate making and printing.

[0122] A chroma value obtaining module is configured to obtain a chroma value CIEL * 0a * 0b * 0of a target color of the laser printed product. * 0C * 0,ab h * 0,ab ;

[0123] A hue difference determination module is configured to determine a hue difference ΔH * of the target color with adjacent color spectrum colors under the same lightness L * and saturation C ab , and convert the hue difference ΔH * ab to a hue angle difference Δh * ab . * ab ;

[0124] A color spectrum page determination module is configured to determine five hue angles centered on the target color according to the chroma value CIEL * 0C * 0,ab h * 0,ab , the hue angle h * 0,ab , and the hue angle difference Δh * ab . * 0C * 0,ab h * 0,ab , the lightness L * 0, and the saturation C * 0,abThe combination is 5 colorimetric values CIEL * a * b * ; 5 said colorimetric values CIEL * a * b * As the center color of 5 color spectrum pages;

[0125] A color spectrum page color determining module is configured to determine the colorimetric values CIEL * a * b * of the center color of each color spectrum page according to the colorimetric values CIEL * C * ab h * ab , and the corresponding colorimetric values CIEL * ab Without changing the hue angle h * , the lightness L * and the saturation C ab are respectively adjusted to obtain all color spectrum colors corresponding to the current color spectrum page;

[0126] A printing CMYK value converting module is configured to convert the colorimetric values CIEL * a * b * of all color spectrum colors corresponding to the center color of each color spectrum page into printing CMYK values under the absolute reproduction intention condition by using an ICC profile;

[0127] A target color all color spectrum page determining module is configured to determine the target color all color spectrum page according to the printing CMYK values of each color spectrum page;

[0128] A laser printing color spectrum determining module is configured to perform printing output and binding on the target color all color spectrum page under the standard process condition to form a laser printing color spectrum.

[0129] In an example embodiment, a computer device is provided, which can be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is configured 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 running the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with external terminals through a network connection. The computer program is executed by the processor to implement a laser printing color spectrum determination method.

[0130] In an example embodiment, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to implement the steps in the above method embodiments.

[0131] In an example embodiment, a computer program product is provided, which includes a computer program. The computer program is executed by a processor to implement the steps in the above method embodiments.

[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 for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of the related data need to comply with relevant regulations.

[0133] Those skilled 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. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to 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 (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.

[0134] The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a blockchain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0135] In the present application, all actions of obtaining signals, information or data are performed in accordance with the corresponding data protection regulations and policies of the country where the device is located, and with the authorization of the owner of the corresponding device.

[0136] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0137] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method of laser printing color determination, comprising: The laser printing color spectrum determination method comprises the following steps: An ICC profile corresponding to a printing output is obtained under standard process conditions of laser printing; the standard process conditions comprise plate making and printing; Acquiring the colorimetric value CIEL of the target color of the laser printed matter * 0a * 0b * 0and the corresponding colorimetric value CIEL * 0C * 0,ab h * 0,ab ; determining the target color in terms of lightness L * and saturation C * ab hue difference ΔH * ab ; and converting the hue difference ΔH * ab to a hue angle difference Δh * ab ; According to the chromaticity value CIEL * 0C * 0,ab h * 0,ab The hue angle h * 0,ab And the hue angle difference Δh * ab Determine 5 hue angles centered on the target color, and all with chromaticity value CIEL * 0C * 0,ab h * 0,ab The middle lightness L * 0And the saturation C * 0,ab Combined into 5 chromaticity values CIEL * a * b * ; 5 said chromaticity values CIEL * a * b * As the center color of the 5 color spectrum pages; According to the chroma value CIEL * a * b * and the corresponding chroma value CIEL * C * ab h * ab , the hue angle h * ab , the lightness L * and the saturation C * ab , respectively, are adjusted without changing the chroma value CIEL C , and all the color spectrum colors corresponding to the current color spectrum page are obtained. The colorimetric values CIEL* a* b* of all color patch colors corresponding to the center color of each color patch page are determined using the ICC profile * a * b * converted to printed CMYK values under absolute reproduction intent conditions; All color spectrum pages of a target color are determined according to printing CMYK values of each color spectrum page; All color spectrum pages of the target color are printed and bound under the standard process conditions to form a laser printing color spectrum.

2. The laser printed chromatographic determination method according to claim 1, characterized in that, The ICC profile has a sampling color number greater than or equal to 900; the ICC profile has an average color difference less than 0.5ΔE * ab ; ΔE * ab is a color difference.

3. The laser printed chromatographic determination method according to claim 1, wherein, The colorimetric value CIEL of the target color of the laser-printed product is acquired * 0a * 0b * 0The corresponding colorimetric value CIEL * 0C * 0,ab h * 0,ab , specifically comprising: When the laser paper base of the laser printing product is a rainbow light column laser paper or a platinum light column laser paper, the size of each sampling color is greater than or equal to 5 cm*1 cm; when the sampling color is measured, an integrating sphere spectrophotometer is used to measure more than 7 measurement points in one complete light column period in the cross direction of the light column; and the sampling interval*the number of collected points is greater than or equal to 1 complete light column period. When the laser paper base of the laser printing product is a plain laser paper as the printing paper base, the shape of the facet of each sample color is a square, and the side length of the square is greater than or equal to 1 cm; when the sample color is measured, the integrating sphere spectrophotometer is used to sample more than or equal to 3 times at different positions, and the average value of the measurement results is taken as the colorimetric value CIEL * 0a * 0b * 0.

4. The laser printed chromatographic determination method according to claim 1, wherein, The target color is determined in lightness L * and saturation C * ab The hue difference ΔH between the color and adjacent chromatic colors under the condition that it remains unchanged * ab ; and the hue difference ΔH * ab Converted to hue angle difference Δh * ab Specifically, it includes: Using the formula The hue difference ΔH is determined * ab ; wherein is the chromatic difference, ΔL * is the lightness difference, is the saturation difference, saturation are the lightness of the target color and the adjacent color, respectively, is the color quality index of the target color, is the color quality index of the adjacent color, Δa * , Δb * are the color quality index difference values of the target color and the adjacent color, respectively, with the subscript 1 representing the colorimetric value of the target color and the subscript 2 representing the colorimetric value of the adjacent color.

5. The laser printed chromatographic determination method according to claim 1, wherein, the chroma value CIEL * a * b * and the corresponding chroma value CIEL * C * ab h * ab , the hue angle h * ab , the lightness L * and the saturation C * ab , respectively, to obtain all the color spectrum colors corresponding to the current color spectrum page, specifically including: With each color spectrum page, the center color is compared with the colors adjacent to it in the up, down, left, and right directions, respectively, to form color differences in terms of lightness increase, lightness decrease, saturation decrease, and saturation increase, and the color differences formed are 0.5 times, 1.0 times, 1.5 times, and up to n times the color difference threshold value of the center color; the changed CIEL * a * b * The color difference values and the color difference values of the center color together constitute the color difference values of all colors of the current color spectrum page, and all colors of the current color spectrum page are formed.

6. The laser printed chromatographic determination method according to claim 1, wherein, The step of printing and binding all color spectrum pages of the target color under the standard process conditions to form a laser printing color spectrum comprises the following steps: All color spectrum pages of the target color are printed and bound under the standard process conditions; An explanation of the printing material, the printing ink and the printing conditions is printed on the first page of the bound pages to form a laser printing color spectrum.

7. A laser printing color spectrum determination system characterized by, The laser printing color spectrum determination system comprises: An ICC profile determination module is configured to obtain an ICC profile corresponding to a printing output under standard process conditions of laser printing; the standard process conditions comprise plate making and printing; The chroma value acquisition module is configured to acquire a chroma value CIEL * 0a * 0b * 0and a corresponding chroma value CIEL * 0C * 0,ab h * 0,ab ; hue difference determining module for determining a target color in lightness L * and saturation C * ab a hue difference ΔH * ab ; and converting the hue difference ΔH * ab to a hue angle difference Δh * ab ; chromaticity value CIEL * 0C * 0,ab h * 0,ab mid hue angle h * 0,ab and hue angle difference Δh * ab determine 5 hue angles centered on the target color and each combined with the chromaticity value CIEL * 0C * 0,ab h * 0,ab mid lightness L * 0 and saturation C * 0,ab into 5 chromaticity values CIEL * a * b * ; 5 said chromaticity values CIEL * a * b * as the center colors of 5 color pages; a colorimetric value CIEL * a * b * and a corresponding colorimetric value CIEL * C * ab h * ab , the hue angle h * ab , the lightness L * and the saturation C * ab , respectively, to obtain all the color spectrum colors corresponding to the current color spectrum page. a print CMYK value conversion module for converting the colorimetric values CIEL * a * b * to print CMYK values under absolute reproduction intent conditions; A target color all color spectrum page determination module is configured to determine all color spectrum pages of a target color according to printing CMYK values of each color spectrum page; A laser printing color spectrum determination module is configured to print and bind all color spectrum pages of the target color under the 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 color spectrum determination method of any one of claims 1-6.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the laser printing color spectrum determination method of any one of claims 1-6.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the laser printing color spectrum determination method of any one of claims 1-6.

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