Printing control method and computer equipment

Abstract

The invention relates to a printing control method and computer equipment. According to the method and the device, the basic contour information of the printed image during full-ink-quantity ink dots is identified, the edge compensation width is determined according to the database information, the basic contour information and the ink-medium-environment-chromatography multivariate model, and the halftone-processed database information is subjected to edge compensation in the edge compensation width; the phenomena of sawteeth, blurring and blurring of the edges of printed characters, graphs and images can be avoided, the edge compensation gradient is set according to the size and the tone type of the printed image, and gradient compensation of a compensation point from the outer edge of the printed image to the center position in the edge compensation width is achieved. The color difference, caused by edge compensation, of the outer edge and the center position is reduced, and low cost and high printing speed are guaranteed while the amount of printing ink is saved.

Description

Technical Field

[0001] This application relates to the field of printing technology, and particularly to a printing control method and a computer device. Background Art

[0002] In digital inkjet printing of books, newspapers, or high-precision labels, the edges of the printed fonts or logos are blurry and the effect is not good, especially for small fonts. In actual production, in order to save the amount of ink and reduce production costs, when converting elements such as text, graphics, and images into digital signals during front-end RIP processing, the overall ink volume of the printed fonts is further reduced, that is, the proportion of ink droplets is reduced, and there will be a lack of ink droplets on the edges of the text, resulting in the formation of jagged edges. From the perspective of the ink droplet distribution of a stroke, for example, the jagged edges formed by the reduction of ink droplets on the upper and lower edges of the horizontal stroke "-" are superimposed, and the visual effect in the horizontal direction will be worse; similarly, for example, the jagged edges formed by the reduction of ink droplets on the left and right edges of the vertical stroke "1" are superimposed, and the visual effect in the vertical direction will be worse. In addition, due to the differences between the ink and the printing medium, the diffusion effect of the ink droplets and the color registration error caused by the mechanical movement of the printing platform, etc., further exacerbate the deterioration of the "blurriness" of the overall printing quality of the font edges.

[0003] Existing solutions are as follows: The first is to improve the processing power of the hardware, increase the resolution of the print head, combine multi-level ink dots to refine the edges, improve the accuracy of the system motion platform, and reduce the color registration impact of mechanical movement, but this will increase the hardware cost, and high-density printing will also reduce the printing speed. The second is as in CN112150397A, by expanding the closed inner cavity of the font to expand the internal space, but this method changes the overall size of the font or the size of the closed area in the text, violating the original design intention and the expected visual effect. The third is as in patent CN114723749B, reducing the boundary pixels of the font to avoid ink overflow during printing, thereby improving clarity, but ignoring the influence of the lateral diffusion and longitudinal absorption characteristics of the ink on the substrate, and ignoring the edge blurring caused by color registration offset during printing, resulting in poor effects. The fourth is to greatly increase the ink volume to improve the contrast of the text part and visually weaken the "blurriness" of the edges, but this will greatly increase the ink volume. For example, using a 100% ink volume to improve the contrast of the text part, but the production cost is also increased, and the adjusted parameters are fixed and cannot be dynamically adjusted, and there may be phenomena such as local ink accumulation and white spots. Summary of the Invention

[0004] Based on this, a printing control method and a computer device are provided to solve the technical problem that the current printing control method cannot avoid jagged edges, blurriness, and edge blurring of printed text, graphics, and images while saving the amount of ink and ensuring low cost and high printing speed.

[0005] On the one hand, a printing control method is provided, the method comprising:

[0006] Read the database information of the printed image in halftone processing to obtain the basic outline information of the printed image when the ink dots are in full ink volume;

[0007] The correlation between printing ink, environmental parameters of the printing site, ink absorption speed of the printing medium and color registration deviation is obtained, and an ink-medium-environment-color registration multivariate model is constructed. The edge compensation width is determined based on the database information, the basic contour information and the ink-medium-environment-color registration multivariate model.

[0008] The size and color type of the printed image are obtained, and the gradient compensation probability gradient from the outer edge of the printed image to the center position within the edge compensation width is determined as the edge compensation gradient based on the size and color type of the printed image.

[0009] Based on the edge compensation gradient, print compensation is performed on the database information to obtain the target print data after print compensation, and the print image is printed according to the target print data.

[0010] In one embodiment, obtaining the basic contour information of the printed image at full ink volume ink dots includes:

[0011] Obtain the type of the printed image, where the type of the printed image includes text;

[0012] Determine if a printed image contains full-volume ink dots;

[0013] If a printed image with full ink volume exists, then obtain the printed dot matrix image covered by ink dots when the printed image has full ink volume.

[0014] If there is no full-ink-volume print image, then the blank points on the edges are filled in by morphological processing to obtain the print dot matrix image covered by ink dots when the print image is full-ink-volume.

[0015] Obtain the maximum contour of the printed dot matrix image to obtain basic contour information.

[0016] In one embodiment, if a printed image with full ink volume is not available, obtaining a printed dot matrix image of the printed image with ink dot coverage when full ink volume is achieved by filling in the blank points at the edges through morphological processing includes:

[0017] Based on the database information of the halftone processing of the printed image, obtain the image of the text to be printed, extract the text outline, and create the edge region;

[0018] Blank points within the edge region are identified using morphological processing methods;

[0019] The blank points within the edge region are filtered to preserve the original stroke shape and sharpness of the printed text;

[0020] The blank points in the filtered edge region are subjected to threshold binarization, and the proportion of ink dots around each blank point is calculated.

[0021] If the proportion of ink dots around the current blank point is greater than the first threshold, ink dot compensation and repair are performed on the current blank point. Based on the edge area of ​​the repaired blank point, the printed dot matrix image of the printed graphic with ink dot coverage when the ink dot volume is full is obtained.

[0022] If the proportion of ink dots around the current blank point is less than or equal to the first threshold, then determine whether the proportion of ink dots around the next blank point is greater than the first threshold.

[0023] In one embodiment, determining the edge compensation width based on the database information, the basic contour information, and the ink-media-environment-color matching multi-dimensional model includes:

[0024] Based on the standard ambient temperature of the printing site, the standard ambient humidity of the printing site, the standard ink absorption speed of the printing medium, the standard color registration deviation, and the target roughness, the basic compensation width of the printed image at the contour edge position is determined by the ink-medium-environment-color registration multivariate model.

[0025] Monitor the relevant printing information acquired by the sensors during the printing process and calculate the measured roughness;

[0026] The basic compensation width is adjusted by tracking the registration error based on the relevant printing information, and / or the basic compensation width is adjusted by a proportional-integral-derivative controller based on the measured roughness.

[0027] In one embodiment, adjusting the base compensation width based on the relevant printing information for registration error tracking includes:

[0028] Based on the relevant printing information, obtain the difference ΔT between the real-time ambient temperature and the standard ambient temperature at the printing site, the difference ΔRH between the real-time ambient humidity and the standard ambient humidity at the printing site, the difference V_ink between the real-time ink absorption speed and the standard ink absorption speed of the printing medium, and the difference Δd between the real-time overprinting error and the color standard deviation.

[0029] Obtain the reference compensation width W_0 of the corresponding printed image size and printing media association settings, wherein the reference compensation width W_0 is positively correlated with the size of the printed image;

[0030] The base compensation width is calculated using the formula W_base=W_0-K_t×ΔT+K_h×ΔRH+K_v×(1 / V_ink)+K_d×Δd, where K_t×ΔT is the temperature compensation amount, K_h×ΔRH is the humidity compensation amount, K_v×(1 / V_ink) is the ink absorption compensation amount, K_d×Δd is the registration misalignment compensation amount, K_t is the temperature compensation coefficient, K_h is the humidity compensation coefficient, K_v is the ink absorption compensation coefficient, and K_d is the registration misalignment compensation coefficient. The temperature compensation coefficient, humidity compensation coefficient, ink absorption compensation coefficient, and registration misalignment compensation coefficient are set according to the type of printing media.

[0031] In one embodiment, adjusting the base compensation width using a proportional-integral-derivative controller based on the measured roughness includes:

[0032] Obtain the target roughness RI_t;

[0033] The edge burr index BI of the printed image is measured, and the edge contrast EC of the printed image is measured. The measured roughness RI is determined by RI=α×BI+β×(1-EC), where α is the weighting coefficient of the edge burr index and β is the weighting coefficient of the edge contrast.

[0034] The dynamic correction amount is calculated by the proportional-integral-derivative controller based on the target roughness RI_t and the measured roughness RI: ΔW_pid=K_p*(RI_t-RI)+K_i*∫(RI_t-RI)dt+K_d*d(RI) / dt, where K_p is the proportional coefficient, Ki is the integral coefficient, and K_d is the derivative coefficient;

[0035] The base compensation width is adjusted according to the dynamic correction amount.

[0036] In one embodiment, measuring the edge burr index BI of the printed image includes:

[0037] Edge detection is performed on the specified text area after printing to obtain a binary edge image;

[0038] Calculate the total number of edge pixels in the binary edge image, and denote it as the actual contour length L_a;

[0039] The region containing the binary edge image is smoothed without burrs. The total number of edge pixels smoothed by morphological closing operation is denoted as the ideal contour length L_i.

[0040] The edge burr index BI is calculated using BI = (L_a - L_i) / L_i.

[0041] On the other hand, a computer device is provided, including 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 steps of a printing control method.

[0042] The aforementioned printing control method and computer equipment identify the basic contour information of the printed image when the ink dots are at full ink volume, and determine the edge compensation width based on database information, basic contour information, and ink-media-environment-color multi-dimensional model. Within the edge compensation width, edge compensation is performed on the database information of halftone processing, which can avoid jagged, blurry, and blurred edges of printed text, graphics, and images. Furthermore, the edge compensation gradient is set according to the size of the printed image and the type of color tone, realizing gradual compensation from the outer edge of the printed image to the compensation point at the center position within the edge compensation width. This reduces the color difference between the outer edge and the center position caused by edge compensation, saving ink while ensuring low cost and high printing speed. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating a printing control method in one embodiment of this application;

[0045] Figure 2 This is a logic diagram of a printing control method in one embodiment of this application;

[0046] Figure 3 This is a schematic diagram of the process of obtaining a print dot matrix image covered by ink dots when there are no full ink dots in a print image according to one embodiment of this application.

[0047] Figure 4 This is a flowchart illustrating the process of calculating the gradient of the ink dot position compensation probability in one embodiment of this application;

[0048] Figure 5 This is a schematic diagram of the concentration or generation probability of the compensation point for the first compensation mode in one embodiment of this application;

[0049] Figure 6 This is a schematic diagram of the concentration or generation probability of the compensation point for the second compensation mode in one embodiment of this application;

[0050] Figure 7 This is a schematic diagram of the compensated edge width in one embodiment of this application;

[0051] Figure 8 This is a schematic diagram of the ink droplet distribution after compensation when the compensation width is 2 in one embodiment of this application;

[0052] Figure 9A This is a schematic diagram of the ink dot position formed by dot enhancement compensation of the character 'm' according to the compensation probability gradient in one embodiment of this application;

[0053] Figure 9B This is a schematic diagram of the ink dot position formed by reducing the dot weakening compensation of the character 'm' according to the compensation probability gradient in one embodiment of this application;

[0054] Figure 10A This is a schematic diagram of the edge shape before and after optimization when the roughness is 0.2265 in one embodiment of this application;

[0055] Figure 10B This is a schematic diagram of the edge shape before and after optimization when the roughness is 0.1022 in one embodiment of this application;

[0056] Figure 11 This is a structural block diagram of a printing control device in one embodiment of this application;

[0057] Figure 12 This is an internal structural diagram of a computer device in one embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0059] As described in the background section, in the printing of high-quality books and labels, the ink coverage density is often reduced to control production costs. This results in insufficient ink coverage at the edges of the printed text due to the reduced ink droplet density, leading to broken strokes and decreased contrast. When the ink reduction exceeds 30%, the loss of edge pixels worsens, causing blurring and jagged edges in the printed text. Furthermore, due to differences in ink absorption speed, slower ink absorption media result in longer lateral ink diffusion times, leading to edge burrs and blurred text; while faster ink absorption media cause excessive vertical ink penetration, resulting in a thinner ink layer, decreased edge contrast, and a visually blurred appearance.

[0060] To address the aforementioned issues, this invention creatively proposes a printing control method. Without altering the original font (and line width) or logo size, and while meeting the requirement of reducing total ink volume by 30%-50%, it considers the influence of ambient temperature and humidity on ink absorption speed and deviations caused by mechanical registration. Through real-time contour roughness analysis, it calculates edge compensation gradients and dynamically optimizes ink droplet distribution in edge areas. This ensures that ink loss in small font stroke connection areas is ≤5%, reducing the impact of blurred font edges and improving printing quality.

[0061] In one embodiment, such as Figure 1 , Figure 2 As shown, a printing control method is provided, including the following steps:

[0062] Step S1: Read the database information of the printed image in halftone processing to obtain the basic contour information of the printed image when the ink dots are in full ink volume.

[0063] Step S2: Obtain the correlation between printing ink, environmental parameters of the printing site, ink absorption speed of the printing medium and color registration deviation, and construct an ink-medium-environment-color registration multivariate model. Determine the edge compensation width based on the database information, the basic contour information and the ink-medium-environment-color registration multivariate model.

[0064] Step S3: Obtain the size and color type of the printed image, and determine the gradient compensation probability gradient from the outer edge of the printed image to the center position within the edge compensation width as the edge compensation gradient based on the size and color type of the printed image.

[0065] Step S4: Perform printing compensation on the database information based on the edge compensation gradient, obtain the target printing data after printing compensation, and print the image according to the target printing data.

[0066] Specifically, by identifying the basic contour information of the printed image when the ink dots are at full ink volume, and determining the edge compensation width based on database information, basic contour information, and ink-media-environment-color multi-dimensional model, edge compensation is performed on the database information of halftone processing within the edge compensation width. This avoids jagged, blurry, and blurred edges of printed text, graphics, and images. Furthermore, the edge compensation gradient is set according to the size of the printed image and the type of color tone, achieving gradual compensation from the outer edge of the printed image to the compensation point at the center position within the edge compensation width. This reduces the color difference between the outer edge and the center position caused by edge compensation, saving ink while ensuring low cost and high printing speed.

[0067] While ensuring production costs are reduced significantly, only a small increase or decrease in ink volume (<5%) is required to achieve a significant improvement in the edge effect of small fonts.

[0068] In this embodiment, obtaining the basic contour information of the printed image at full ink volume ink dots includes:

[0069] Obtain the type of the printed image, where the type of the printed image includes text;

[0070] Determine if a printed image contains full-volume ink dots;

[0071] If a printed image with full ink volume exists, then obtain the printed dot matrix image covered by ink dots when the printed image has full ink volume.

[0072] If there is no full-ink-volume print image, then the blank points on the edges are filled in by morphological processing to obtain the print dot matrix image covered by ink dots when the print image is full-ink-volume.

[0073] Obtain the maximum contour of the printed dot matrix image to obtain basic contour information.

[0074] like Figure 3 As shown, in this embodiment, if there is no full-ink-volume printed image, then obtaining the printed dot matrix image covered by ink dots when there are full-ink dots after filling in the blank points at the edges through morphological processing includes:

[0075] Based on the database information of the halftone processing of the printed image, obtain the image of the text to be printed, extract the text outline, and create the edge region;

[0076] Blank points within the edge region are identified using morphological processing methods;

[0077] The blank points within the edge region are filtered to preserve the original stroke shape and sharpness of the printed text;

[0078] The blank points in the filtered edge region are subjected to threshold binarization, and the proportion of ink dots around each blank point is calculated.

[0079] If the proportion of ink dots around the current blank point is greater than the first threshold, ink dot compensation and repair are performed on the current blank point. Based on the edge area of ​​the repaired blank point, the printed dot matrix image of the printed graphic with ink dot coverage when the ink dot volume is full is obtained.

[0080] If the proportion of ink dots around the current blank point is less than or equal to the first threshold, then determine whether the proportion of ink dots around the next blank point is greater than the first threshold.

[0081] This requires obtaining a base contour (also the maximum contour) of a print dot matrix image covering 100% of the ink volume of the text to be printed for subsequent compensation calculations; if this 100% ink volume image data is unavailable, the base contour (maximum contour) can also be obtained from the current halftone image by using morphological processing to fill in the gaps at the edges.

[0082] Filtering only the current blank point avoids modifying existing ink dots, thus better preserving the shape and sharpness of the original strokes. A weighted average kernel is used in the neighborhood analysis calculation, with the center point having a weight of 0 (ignoring itself), to calculate the proportion of ink dots surrounding each blank point. When using a first threshold control, a threshold of 0.4 indicates that repair is performed when more than 40% of the surrounding pixels are ink dots. The first threshold can be adjusted to suit different situations.

[0083] In this embodiment, determining the edge compensation width based on the database information, the basic contour information, and the ink-media-environment-color matching multi-dimensional model includes:

[0084] Based on the standard ambient temperature of the printing site, the standard ambient humidity of the printing site, the standard ink absorption speed of the printing medium, the standard color registration deviation, and the target roughness, the basic compensation width of the printed image at the contour edge position is determined by the ink-medium-environment-color registration multivariate model.

[0085] Monitor the relevant printing information acquired by the sensors during the printing process and calculate the measured roughness;

[0086] The basic compensation width is adjusted by tracking the registration error based on the relevant printing information, and / or the basic compensation width is adjusted by a proportional-integral-derivative controller based on the measured roughness.

[0087] The ink-medium-environment-color matching multi-element model is combined with a dynamic feedback model with roughness as the control target.

[0088] A dynamic optimization system is developed based on real-time acquisition and analysis of the outline roughness of the printed text, calculating the distribution of ink droplets at the text edges. The system flow is as follows: Figure 2 As shown.

[0089] Ink droplets need to be quickly fixed on the paper surface and prevented from spreading, requiring a precise match between the paper's pore structure (causing pore differences) and the ink solvent absorption rate; piezoelectric printheads are sensitive to changes in ink viscosity, while paper moisture content affects the ink absorption path, requiring compensation; and the differences in these factors will affect the printing effect of text edges, so existing empirical data related to the printing media are retrieved from the experience database to participate in the basic compensation width calculation.

[0090] In this embodiment, adjusting the basic compensation width based on the registration error tracking according to the relevant printing information includes:

[0091] Based on the relevant printing information, obtain the difference ΔT between the real-time ambient temperature and the standard ambient temperature at the printing site, the difference ΔRH between the real-time ambient humidity and the standard ambient humidity at the printing site, the difference V_ink between the real-time ink absorption speed and the standard ink absorption speed of the printing medium, and the difference Δd between the real-time overprinting error and the color standard deviation.

[0092] Obtain the reference compensation width W_0 of the corresponding printed image size and printing media association settings, wherein the reference compensation width W_0 is positively correlated with the size of the printed image;

[0093] The base compensation width is calculated using the formula W_base=W_0-K_t×ΔT+K_h×ΔRH+K_v×(1 / V_ink)+K_d×Δd, where K_t×ΔT is the temperature compensation amount, K_h×ΔRH is the humidity compensation amount, K_v×(1 / V_ink) is the ink absorption compensation amount, K_d×Δd is the registration misalignment compensation amount, K_t is the temperature compensation coefficient, K_h is the humidity compensation coefficient, K_v is the ink absorption compensation coefficient, and K_d is the registration misalignment compensation coefficient. The temperature compensation coefficient, humidity compensation coefficient, ink absorption compensation coefficient, and registration misalignment compensation coefficient are set according to the type of printing media.

[0094] The initial text edge compensation width is calculated by combining the printing site conditions (temperature, humidity). That is, the current design employs a feedforward-feedback collaborative control model, focusing on five core parameters (temperature, humidity, media ink absorption speed, color registration deviation, and surface roughness) to achieve a balance between "high performance and low complexity."

[0095] Temperature change compensation is performed based on the difference ΔT between the real-time ambient temperature at the printing site and the standard ambient temperature:

[0096] Temperature increases → ink viscosity decreases → surface tension decreases → diffusion increases → edge compensation width needs to be reduced.

[0097] Humidity change compensation is performed based on the difference ΔRH between the real-time ambient humidity at the printing site and the standard ambient humidity:

[0098] Increased humidity leads to decreased drying speed, which in turn increases diffusion time, requiring a reduction in edge compensation width.

[0099] The ink absorption speed variation is compensated based on the difference V_ink between the real-time ink absorption speed of the printing media and the standard ink absorption speed:

[0100] Ink absorption speed decreases → drying time increases → diffusion increases → edge compensation width needs to be reduced.

[0101] Based on the difference Δd between the real-time overprinting error and the color standard deviation, the landing point deviation is measured by the sensor to characterize the deviation between the actual overprinting error and the threshold (overprinting error compensation). When Δd increases, adjacent ink dots cannot be accurately connected, resulting in edge misalignment, uneven grayscale caused by the distortion of ink distribution in the edge area, and decreased clarity perceived by the human eye, resulting in blurry fonts. The edge compensation width needs to be adjusted.

[0102] The input parameters for calculating the base compensation width W_base are shown in Table 1.

[0103] Table 1 Input Parameters

[0104] parameter symbol How to obtain Temperature deviation ΔT Temperature sensor (±0.5℃) Humidity deviation ΔRH Humidity sensor (±3% RH) Media ink absorption speed V_ink Media database query (preset levels 1-5) Color registration deviation Δd Online visual inspection (±0.1mm)

[0105] The reference compensation width W_0 is positively correlated with the size of the printed image, such as a 6pt font size on coated paper = 0.10mm.

[0106] The temperature compensation coefficient, humidity compensation coefficient, ink absorption compensation coefficient, and registration misalignment compensation coefficient are set according to the type of printing media, as shown in Table 2.

[0107] Table 2 Typical values ​​of parameters

[0108] parameter Type 1 paper Type II paper Type III paper K_t 0.004mm / ℃ 0.006mm / ℃ 0.008mm / ℃ K_h 0.002mm / %RH 0.003mm / %RH 0.005mm / %RH K_v 0.015 0.035 0.065 K_d 0.12mm / mm 0.18mm / mm 0.15mm / mm W_0 0.12mm 0.15mm 0.18mm

[0109] The calculated base compensation width serves as the control feedforward output and does not need to be calculated in real-time during production printing. It is updated as needed: for example, when the dryer malfunctions or media is switched, the parameters are updated from the database. Regarding registration errors, the system only monitors registration changes in real time, and triggers the calculation of the base compensation width only when the error exceeds a certain threshold.

[0110] That is, determining the edge compensation width based on the database information, the basic contour information, and the ink-media-environment-color matching multi-element model includes:

[0111] Based on the standard ambient temperature of the printing site, the standard ambient humidity of the printing site, the standard ink absorption speed of the printing medium, the standard color registration deviation, and the target roughness, the basic compensation width of the printed image at the contour edge position is determined by the ink-medium-environment-color registration multivariate model.

[0112] The changes in the standard ambient temperature, standard ambient humidity, standard ink absorption speed of the printing medium, standard color registration deviation, and target roughness of the printing site are detected.

[0113] When any of the following changes exceed a preset limit: the change in standard ambient temperature at the printing site, the change in standard ambient humidity at the printing site, the change in standard ink absorption speed of the printing medium, the change in color registration standard deviation, or the change in target roughness, the basic compensation width is corrected; otherwise, the basic compensation width remains unchanged.

[0114] In this embodiment, adjusting the basic compensation width using a proportional-integral-derivative controller based on the measured roughness includes:

[0115] Obtain the target roughness RI_t;

[0116] The edge burr index BI of the printed image is measured, and the edge contrast EC of the printed image is measured. The measured roughness RI is determined by RI=α×BI+β×(1-EC), where α is the weighting coefficient of the edge burr index and β is the weighting coefficient of the edge contrast.

[0117] The dynamic correction amount is calculated by the proportional-integral-derivative controller based on the target roughness RI_t and the measured roughness RI: ΔW_pid=K_p*(RI_t-RI)+K_i*∫(RI_t-RI)dt+K_d*d(RI) / dt, where K_p is the proportional coefficient, Ki is the integral coefficient, and K_d is the derivative coefficient;

[0118] The base compensation width is adjusted according to the dynamic correction amount.

[0119] Roughness is determined by two components: the edge burr index (BI) and the edge sharpness (EC). The burr index indicates the degree of burr on the edge; a higher BI indicates more burrs and thus higher roughness. A higher EC indicates sharper edges and lower roughness. α and β are weighting coefficients; for example, α = 0.7 and β = 0.3 are used to emphasize the effect of burrs: RI = 0.7 × BI + 0.3 × (1 - EC). The final compensation width is W_s = cL_amp(W_base + ΔW_pid).

[0120] The system integrates a high-resolution line scan camera (≥1200dpi) and an FPGA processing unit to measure the edge burr index (BI) and edge contrast (EC) of the printed image, completes the RI calculation within 50ms and feeds it back to the inkjet controller; the camera is also used to track registration error, triggering the calculation of the basic compensation width when the registration error reaches a specified threshold.

[0121] In this embodiment, measuring the edge burr index BI of the printed image includes:

[0122] Edge detection is performed on the specified text area after printing to obtain a binary edge image;

[0123] Calculate the total number of edge pixels in the binary edge image, and denote it as the actual contour length L_a;

[0124] The region containing the binary edge image is smoothed without burrs. The total number of edge pixels smoothed by morphological closing operation is denoted as the ideal contour length L_i.

[0125] The edge burr index BI is calculated using BI = (L_a - L_i) / L_i.

[0126] In this embodiment, measuring the edge contrast EC of the printed image includes:

[0127] For each edge pixel, take the grayscale values ​​of three pixels on either side of the edge normal direction, calculate the grayscale difference between the inner and outer sides of the edge normal direction, and average the grayscale differences of all edge pixels to obtain the average edge contrast. Divide the average edge contrast by 255 to normalize and obtain the edge contrast ratio: EC = average edge contrast ratio / 255; or

[0128] Get the maximum gray value G_max of the edge region of the printed image, get the minimum gray value G_min of the background region, and calculate the edge contrast EC by EC = (G_max - G_min) / 255.

[0129] In this embodiment, obtaining the size and color tone of the printed image, and determining the gradient compensation probability gradient of the compensation point from the outer edge to the center position within the edge compensation width as the edge compensation gradient based on the size and color tone of the printed image includes:

[0130] Obtain the color tone type of the printed image, which includes dominant color tone, base color tone, non-dominant color tone, and non-base color tone;

[0131] When the color tone is the main color tone or the base color tone, the density or number of compensation points set within the edge compensation width from the outer edge of the printed image to the center position gradually decreases, and the generation probability of compensation points set within the edge compensation width from the outer edge of the printed image to the center position gradually decreases.

[0132] When the color tone is a non-dominant color tone or a non-base color tone, the density or number of compensation points set within the edge compensation width from the outer edge of the printed image to the center gradually increases, and the generation probability of compensation points set within the edge compensation width from the outer edge of the printed image to the center gradually increases.

[0133] The shape of the printed image is obtained, and straight line types and curved line types are identified along the edge of the printed image shape. The number of compensation points set at the curved line type position is greater than the number of compensation points at the straight line type position.

[0134] The concentration, number, and generation probability of compensation points within the edge compensation width are used as the edge compensation gradient.

[0135] The gradient logic for constructing the compensation ink droplets is as follows: the number of compensation ink droplets in areas far from the center of the font strokes gradually changes (increases or decreases) towards the center of the strokes, strengthening or weakening the edges to achieve the purpose of optimizing roughness.

[0136] The printing process inserts specific text and images into the non-product area of ​​the printing medium. An image sensor captures the printed image, and the outline roughness of the printed font is calculated in real time. This printed image can also contain patterns such as crosses, circles, and triangles to calculate color registration errors and implement real-time tracking of registration errors. When the registration error reaches a certain upper limit, it triggers an update of the base compensation width.

[0137] To accommodate fonts of different sizes and stroke thicknesses with varying uniformity in compensation, the pixel width of edge compensation for larger fonts is greater than that for smaller fonts, and the number of compensation points decreases linearly or linearly from the outline to the stroke center. Alternatively, the number of compensation points can decrease non-linearly or non-linearly; non-linear methods produce better results but have higher computational complexity. The camera captures a printed image of a specified location, which is then noise-filtered, subjected to distance transformation, and then... Figure 4 The processing calculation mentioned above treats it as the gradient of the ink dot position compensation probability.

[0138] The actual gradient may present two different forms due to the influence of factors such as the medium, ink, and color matching mentioned above:

[0139] like Figure 5 As shown, the first type of compensation is enhancement compensation, where the concentration or generation probability of the compensation point gradually decreases from the outer contour towards the center. That is, the closer to the outer edge, the more ink droplets are compensated (increased). This type is used to strengthen the outer edge and is usually used for the main color tone or the reference color tone for registration. Figure 5 This is a diagram illustrating the compensation gradient at the top right corner of the character 'm'. Figure 5 The position with a median value of 1 represents the position of the outermost contour, indicating that these positions have a higher probability of needing to be filled in. The value gradually decreases to 0 along the direction of the arrow shown in the figure (i.e., the gradient direction of the compensation probability).

[0140] like Figure 6As shown, the second type of compensation is weakening compensation, where the intensity (or number) of the reduction in dots gradually decreases from the outer contour towards the center. The closer to the outer edge, the more ink droplets are compensated (reduced). This type is used to weaken the outer edge and is usually used for non-primary tones or tones with registration deviation. Figure 6 This is a diagram illustrating the compensation gradient at the top right corner of the character 'm'.

[0141] By adjusting the above two methods, a stepped ink droplet density distribution is applied to the edges of the printed text to enhance the edge effect and reduce edge roughness.

[0142] After calculating the compensation gradient, compensation is applied by increasing or decreasing ink droplets according to the compensation probability gradient at each location. For example... Figure 7 , Figure 8 As shown, Figure 7 Indicates the edge width of the compensation. Figure 8 This indicates the distribution of ink droplets after compensation when the compensation width is 2.

[0143] like Figure 9A , Figure 9B As shown, the ink dot positions are formed by the compensated probability gradient of the character 'm'.

[0144] For cases requiring edge enhancement, the locations of the ink droplets needing compensation are selected based on the compensation probability gradient. Figure 9A It can be seen that the black dots are the locations where ink droplets need to be added, and the closer to the edge, the more dots need to be added (up to 100%). From the edge to the center, the number of locations where ink droplets need to be added decreases within the compensation width, down to 0%. For different compensation widths, the range of compensation dots from the edge to the center is different.

[0145] For cases requiring edge weakening, the locations of ink droplets needing compensation are selected based on the compensation probability gradient. Figure 9B As can be seen, the black dots represent the locations where ink droplets need to be reduced, and the closer to the edge, the more droplets need to be reduced (up to 100%). From the edge to the center, within the compensation width, the number of locations where ink droplets need to be reduced decreases, down to 0%. For different compensation widths, the range of compensation points from the edge to the center varies.

[0146] This involves calculating both the target roughness and the measured roughness for PID dynamic adjustment. The target roughness is a pre-designed image of the text with 100% ink volume, where the distribution of edge points is a smooth, noise-free image, representing the ideal effect to be achieved after optimizing the edge ink droplet distribution. Figure 10A , Figure 10B It shows the calculated results of the edges after the camera takes a picture, and you can see the difference in edge roughness before and after optimization. Figure 10AThis is a schematic diagram of the edge shape before and after optimization when the roughness is 0.2265; Figure 10B The diagram shows the edge shape before and after optimization when the roughness is 0.1022. The comparison shows that the more ink droplets there are, the smaller the edge roughness.

[0147] When calculating the compensation probability gradient, a distance transformation is performed on the complete contour to obtain the distance from the edge to the center, which is also the limit of the compensation width. Generally, the compensation width will be less than this limit width, otherwise it will affect the ink volume requirements and density effect of the original printing design.

[0148] In the above-mentioned printing control method, by identifying the basic contour information of the printed image when the ink dots are at full ink volume, and determining the edge compensation width based on the database information, basic contour information, and ink-media-environment-color multi-dimensional model, edge compensation is performed on the database information of halftone processing within the edge compensation width. This can avoid jagged, blurry, and blurred edges of printed text, graphics, and images. Furthermore, the edge compensation gradient is set according to the size of the printed image and the color type, realizing gradual compensation from the outer edge of the printed image to the compensation point at the center position within the edge compensation width. This reduces the color difference between the outer edge and the center position caused by edge compensation, saving ink while ensuring low cost and high printing speed.

[0149] In one embodiment, such as Figure 11 As shown, a printing control device 10 is provided, including: an initial information acquisition module 1, an edge compensation width determination module 2, an edge compensation gradient setting module 3, and a compensation printing module 4.

[0150] The initial information acquisition module 1 is used to read the database information of the printed image in halftone processing and obtain the basic contour information of the printed image when the ink dots are in full ink volume.

[0151] The edge compensation width determination module 2 is used to obtain the correlation between printing ink, environmental parameters of the printing site, ink absorption speed of the printing medium and color registration deviation, and construct an ink-medium-environment-color registration multivariate model. The edge compensation width is determined based on the database information, the basic contour information and the ink-medium-environment-color registration multivariate model.

[0152] The edge compensation gradient setting module 3 is used to obtain the size and color type of the printed image, and determine the gradient compensation probability gradient from the outer edge of the printed image to the center position within the edge compensation width as the edge compensation gradient based on the size and color type of the printed image.

[0153] The compensation printing module 4 is used to perform printing compensation on the database information based on the edge compensation gradient, obtain the target printing data after printing compensation, and print the printing image according to the target printing data.

[0154] In this embodiment, obtaining the basic contour information of the printed image at full ink volume ink dots includes:

[0155] Obtain the type of the printed image, where the type of the printed image includes text;

[0156] Determine if a printed image contains full-volume ink dots;

[0157] If a printed image with full ink volume exists, then obtain the printed dot matrix image covered by ink dots when the printed image has full ink volume.

[0158] If there is no full-ink-volume print image, then the blank points on the edges are filled in by morphological processing to obtain the print dot matrix image covered by ink dots when the print image is full-ink-volume.

[0159] Obtain the maximum contour of the printed dot matrix image to obtain basic contour information.

[0160] In this embodiment, if a printed image with full ink volume does not exist, then obtaining a printed dot matrix image with ink dot coverage when full ink volume is achieved by filling in the blank points at the edges through morphological processing includes:

[0161] Based on the database information of the halftone processing of the printed image, obtain the image of the text to be printed, extract the text outline, and create the edge region;

[0162] Blank points within the edge region are identified using morphological processing methods;

[0163] The blank points within the edge region are filtered to preserve the original stroke shape and sharpness of the printed text;

[0164] The blank points in the filtered edge region are subjected to threshold binarization, and the proportion of ink dots around each blank point is calculated.

[0165] If the proportion of ink dots around the current blank point is greater than the first threshold, ink dot compensation and repair are performed on the current blank point. Based on the edge area of ​​the repaired blank point, the printed dot matrix image of the printed graphic with ink dot coverage when the ink dot volume is full is obtained.

[0166] If the proportion of ink dots around the current blank point is less than or equal to the first threshold, then determine whether the proportion of ink dots around the next blank point is greater than the first threshold.

[0167] In this embodiment, determining the edge compensation width based on the database information, the basic contour information, and the ink-media-environment-color matching multi-dimensional model includes:

[0168] Based on the standard ambient temperature of the printing site, the standard ambient humidity of the printing site, the standard ink absorption speed of the printing medium, the standard color registration deviation, and the target roughness, the basic compensation width of the printed image at the contour edge position is determined by the ink-medium-environment-color registration multivariate model.

[0169] Monitor the relevant printing information acquired by the sensors during the printing process and calculate the measured roughness;

[0170] The basic compensation width is adjusted by tracking the registration error based on the relevant printing information, and / or the basic compensation width is adjusted by a proportional-integral-derivative controller based on the measured roughness.

[0171] In this embodiment, adjusting the basic compensation width based on the registration error tracking according to the relevant printing information includes:

[0172] Based on the relevant printing information, obtain the difference ΔT between the real-time ambient temperature and the standard ambient temperature at the printing site, the difference ΔRH between the real-time ambient humidity and the standard ambient humidity at the printing site, the difference V_ink between the real-time ink absorption speed and the standard ink absorption speed of the printing medium, and the difference Δd between the real-time overprinting error and the color standard deviation.

[0173] Obtain the reference compensation width W_0 of the corresponding printed image size and printing media association settings, wherein the reference compensation width W_0 is positively correlated with the size of the printed image;

[0174] The base compensation width is calculated using the formula W_base=W_0-K_t×ΔT+K_h×ΔRH+K_v×(1 / V_ink)+K_d×Δd, where K_t×ΔT is the temperature compensation amount, K_h×ΔRH is the humidity compensation amount, K_v×(1 / V_ink) is the ink absorption compensation amount, K_d×Δd is the registration misalignment compensation amount, K_t is the temperature compensation coefficient, K_h is the humidity compensation coefficient, K_v is the ink absorption compensation coefficient, and K_d is the registration misalignment compensation coefficient. The temperature compensation coefficient, humidity compensation coefficient, ink absorption compensation coefficient, and registration misalignment compensation coefficient are set according to the type of printing media.

[0175] In this embodiment, adjusting the basic compensation width using a proportional-integral-derivative controller based on the measured roughness includes:

[0176] Obtain the target roughness RI_t;

[0177] The edge burr index BI of the printed image is measured, and the edge contrast EC of the printed image is measured. The measured roughness RI is determined by RI=α×BI+β×(1-EC), where α is the weighting coefficient of the edge burr index and β is the weighting coefficient of the edge contrast.

[0178] The dynamic correction amount is calculated by the proportional-integral-derivative controller based on the target roughness RI_t and the measured roughness RI: ΔW_pid=K_p*(RI_t-RI)+K_i*∫(RI_t-RI)dt+K_d*d(RI) / dt, where K_p is the proportional coefficient, Ki is the integral coefficient, and K_d is the derivative coefficient;

[0179] The base compensation width is adjusted according to the dynamic correction amount.

[0180] In this embodiment, measuring the edge burr index BI of the printed image includes:

[0181] Edge detection is performed on the specified text area after printing to obtain a binary edge image;

[0182] Calculate the total number of edge pixels in the binary edge image, and denote it as the actual contour length L_a;

[0183] The region containing the binary edge image is smoothed without burrs. The total number of edge pixels smoothed by morphological closing operation is denoted as the ideal contour length L_i.

[0184] The edge burr index BI is calculated using BI = (L_a - L_i) / L_i.

[0185] In this embodiment, measuring the edge contrast EC of the printed image includes:

[0186] For each edge pixel, take the grayscale values ​​of three pixels on either side of the edge normal direction, calculate the grayscale difference between the inner and outer sides of the edge normal direction, and average the grayscale differences of all edge pixels to obtain the average edge contrast. Divide the average edge contrast by 255 to normalize and obtain the edge contrast ratio: EC = average edge contrast ratio / 255; or

[0187] Get the maximum gray value G_max of the edge region of the printed image, get the minimum gray value G_min of the background region, and calculate the edge contrast EC by EC = (G_max - G_min) / 255.

[0188] In this embodiment, obtaining the size and color tone of the printed image, and determining the gradient compensation probability gradient of the compensation point from the outer edge to the center position within the edge compensation width as the edge compensation gradient based on the size and color tone of the printed image includes:

[0189] Obtain the color tone type of the printed image, which includes dominant color tone, base color tone, non-dominant color tone, and non-base color tone;

[0190] When the color tone is the main color tone or the base color tone, the density or number of compensation points set within the edge compensation width from the outer edge of the printed image to the center position gradually decreases, and the generation probability of compensation points set within the edge compensation width from the outer edge of the printed image to the center position gradually decreases.

[0191] When the color tone is a non-dominant color tone or a non-base color tone, the density or number of compensation points set within the edge compensation width from the outer edge of the printed image to the center gradually increases, and the generation probability of compensation points set within the edge compensation width from the outer edge of the printed image to the center gradually increases.

[0192] The shape of the printed image is obtained, and straight line types and curved line types are identified along the edge of the printed image shape. The number of compensation points set at the curved line type position is greater than the number of compensation points at the straight line type position.

[0193] The concentration, number, and generation probability of compensation points within the edge compensation width are used as the edge compensation gradient.

[0194] In the aforementioned printing control device, by identifying the basic contour information of the printed image when the ink dots are at full ink volume, and determining the edge compensation width based on database information, basic contour information, and ink-media-environment-color multi-dimensional model, edge compensation is performed on the database information of halftone processing within the edge compensation width. This avoids jagged, blurry, and blurred edges of printed text, graphics, and images. Furthermore, by setting the edge compensation gradient according to the size of the printed image and the type of color tone, a gradual compensation is achieved from the outer edge of the printed image to the compensation point at the center position within the edge compensation width. This reduces the color difference between the outer edge and the center position caused by edge compensation, saving ink while ensuring low cost and high printing speed.

[0195] Specific limitations regarding the print control device can be found in the limitations of the print control method described above, and will not be repeated here. Each module in the aforementioned print control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in the computer device, or stored in software in the memory of the computer device, so that the processor can call and execute the operations corresponding to each module.

[0196] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 12As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database stores print control data. The network interface communicates with external terminals via a network connection. When the computer program is executed by the processor, it implements a print control method.

[0197] Those skilled in the art will understand that Figure 12 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0198] In one embodiment, a computer device is provided, including 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 perform the following steps:

[0199] Read the database information of the printed image in halftone processing to obtain the basic outline information of the printed image when the ink dots are in full ink volume;

[0200] The correlation between printing ink, environmental parameters of the printing site, ink absorption speed of the printing medium and color registration deviation is obtained, and an ink-medium-environment-color registration multivariate model is constructed. The edge compensation width is determined based on the database information, the basic contour information and the ink-medium-environment-color registration multivariate model.

[0201] The size and color type of the printed image are obtained, and the gradient compensation probability gradient from the outer edge of the printed image to the center position within the edge compensation width is determined as the edge compensation gradient based on the size and color type of the printed image.

[0202] Based on the edge compensation gradient, print compensation is performed on the database information to obtain the target print data after print compensation, and the print image is printed according to the target print data.

[0203] For specific limitations on the steps a processor takes when executing a computer program, please refer to the limitations on printing control methods mentioned above, which will not be repeated here.

[0204] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0205] Read the database information of the printed image in halftone processing to obtain the basic outline information of the printed image when the ink dots are in full ink volume;

[0206] The correlation between printing ink, environmental parameters of the printing site, ink absorption speed of the printing medium and color registration deviation is obtained, and an ink-medium-environment-color registration multivariate model is constructed. The edge compensation width is determined based on the database information, the basic contour information and the ink-medium-environment-color registration multivariate model.

[0207] The size and color type of the printed image are obtained, and the gradient compensation probability gradient from the outer edge of the printed image to the center position within the edge compensation width is determined as the edge compensation gradient based on the size and color type of the printed image.

[0208] Based on the edge compensation gradient, print compensation is performed on the database information to obtain the target print data after print compensation, and the print image is printed according to the target print data.

[0209] For specific limitations on the steps implemented when a computer program is executed by a processor, please refer to the limitations on printing control methods mentioned above, which will not be repeated here.

[0210] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAM bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0211] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0212] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A print control method characterized by, The method comprises the following steps: reading database information of a print image in halftone processing, obtaining basic outline information of the print image in full ink amount dots; obtaining a correlation between print ink, an environment parameter of a print site, an ink absorption speed of a print medium and color registration deviation and constructing an ink-medium-environment-color registration multi-element model, determining an edge compensation width according to the database information, the basic outline information and the ink-medium-environment-color registration multi-element model; obtaining a size and a color tone type of the print image, determining a gradient compensation probability gradient of a compensation point from an external edge to a center position within the edge compensation width as an edge compensation gradient according to the size and the color tone type of the print image; performing print compensation on the database information based on the edge compensation gradient, obtaining target print data after print compensation, and printing the print image according to the target print data.

2. The print control method according to claim 1, characterized by, The method for obtaining the basic outline information of the print image in full ink amount dots comprises the following steps: obtaining a type of the print image, wherein the type of the print image comprises a character; determining whether there is a print image with full ink amount dots; if there is a print image with full ink amount dots, obtaining a print dot matrix image covered by ink dots of the print image in full ink amount dots; if there is no print image with full ink amount dots, obtaining a print dot matrix image covered by ink dots of the print image in full ink amount dots after blank points of an edge are filled through a morphological processing mode; obtaining a maximum outline of the print dot matrix image to obtain the basic outline information.

3. The print control method according to claim 2, characterized by, The method for obtaining the print dot matrix image covered by ink dots of the print image in full ink amount dots after blank points of an edge are filled through a morphological processing mode if there is no print image with full ink amount dots comprises the following steps: obtaining an image of a to-be-printed character according to database information of a print image in halftone processing, extracting a character outline and creating an edge region; recognizing blank points in the edge region through a morphological processing mode; filtering the blank points in the edge region to maintain original stroke shapes and sharpness of the print character; performing threshold binary processing on the blank points in the filtered edge region, and calculating a proportion value of ink dot pixels around each blank point; if the proportion value of ink dot pixels around a current blank point is greater than a first threshold value, performing ink dot compensation repair on the current blank point, and obtaining a print dot matrix image covered by ink dots of the print image in full ink amount dots based on the edge region of the filled blank point after repair; if the proportion value of ink dot pixels around the current blank point is less than or equal to the first threshold value, determining whether the proportion value of ink dot pixels around a next blank point is greater than the first threshold value.

4. The print control method according to claim 1, characterized by, The method for determining the edge compensation width according to the database information, the basic outline information and the ink-medium-environment-color registration multi-element model comprises the following steps: determining a basic compensation width of a print image at an outline edge position through the ink-medium-environment-color registration multi-element model according to a standard environment temperature of a print site, a standard environment humidity of the print site, a standard ink absorption speed of a print medium, a color registration standard deviation and a target roughness; monitoring relevant print information obtained by a sensor in a print process, and calculating a measured roughness. The base compensation width is adjusted according to the associated printing information by tracking the misregistration error, and / or the base compensation width is adjusted by a proportional-integral-derivative controller according to the measured roughness.

5. The print control method according to claim 4, characterized by, The base compensation width is adjusted according to the associated printing information by tracking the misregistration error, and the base compensation width is adjusted by a proportional-integral-derivative controller according to the measured roughness. According to the associated printing information, a difference ΔT between a real-time ambient temperature and a standard ambient temperature of a printing site is obtained, a difference ΔRH between a real-time ambient humidity and a standard ambient humidity of the printing site is obtained, a difference V_ink between a real-time ink absorption speed and a standard ink absorption speed of a printing medium is obtained, and a difference Δd between a real-time overprint error and a standard overprint deviation is obtained. A reference compensation width W_0 corresponding to a size of a printing image and an associated setting of a printing medium is obtained, and the reference compensation width W_0 is positively correlated with the size of the printing image. The base compensation width is calculated by a formula W_base=W_0-K_t×ΔT+K_h×ΔRH+K_v×(1 / V_ink)+K_d×Δd, wherein K_t×ΔT is a temperature compensation amount, K_h×ΔRH is a humidity compensation amount, K_v×(1 / V_ink) is an ink absorption compensation amount, K_d×Δd is a misregistration compensation amount, K_t is a temperature compensation coefficient, K_h is a humidity compensation coefficient, K_v is an ink absorption compensation coefficient, and K_d is a misregistration compensation coefficient, and the temperature compensation coefficient, the humidity compensation coefficient, the ink absorption compensation coefficient, and the misregistration compensation coefficient are set according to a type of the printing medium.

6. The print control method according to claim 4, characterized by, The base compensation width is adjusted by a proportional-integral-derivative controller according to the measured roughness, and the base compensation width is adjusted according to the dynamic correction amount. A target roughness RI_t is obtained. An edge burr index BI of the printing image is measured, an edge contrast EC of the printing image is measured, and the measured roughness RI is determined by RI=α×BI+β×(1-EC), wherein α is an edge burr index weight coefficient, and β is an edge contrast weight coefficient. A dynamic correction amount ΔW_pid is calculated by a proportional-integral-derivative controller according to the target roughness RI_t and the measured roughness RI, wherein ΔW_pid=K_p*(RI_t-RI)+K_i*∫(RI_t-RI)dt+K_d*d(RI) / dt, K_p is a proportional coefficient, K_i is an integral coefficient, and K_d is a differential coefficient. The base compensation width is adjusted according to the dynamic correction amount.

7. The print control method according to claim 6, wherein The edge burr index BI of the printing image is measured, and the edge burr index BI is calculated by BI=(L_a-L_i) / L_i, wherein L_a is a total number of edge pixels of a binary edge image obtained by performing edge detection on a specified character region after printing, and L_i is an ideal contour length of the binary edge image obtained by performing non-burr smoothing processing on a region where the binary edge image is located and performing morphological closing operation to smooth the total number of edge pixels. The edge contrast EC of the printing image is measured. ​ ​ ​ 8. The print control method according to claim 6, characterized by, ​ For each edge pixel, the gray scale values of three pixel points on both sides of the edge normal direction are taken, the gray scale difference values on both sides of the edge normal direction are calculated, the average gray scale difference of all edge pixels is obtained, the average edge contrast is obtained, the average edge contrast is divided by 255 to obtain the edge contrast: EC=average edge contrast / 255; or The maximum gray scale value G_max of the edge region of the printed image is obtained, the minimum gray scale value G_min of the background region is obtained, and the edge contrast EC is calculated by EC=(G_max-G_min) / 255.

9. The print control method according to claim 1, wherein The size and tone category of the printed image are obtained, and a gradual compensation probability gradient of a compensation point from an external edge to a center position within the edge compensation width is determined as an edge compensation gradient according to the size and tone category of the printed image. The tone category of the printed image is obtained, and the tone category includes a main tone, a reference tone, a non-main tone, and a non-reference tone. When the tone category is a main tone or a reference tone, the density or quantity of the compensation point from the external edge to the center position within the edge compensation width is gradually reduced, and the generation probability of the compensation point from the external edge to the center position within the edge compensation width is gradually reduced. When the tone category is a non-main tone or a non-reference tone, the density or quantity of the compensation point from the external edge to the center position within the edge compensation width is gradually increased, and the generation probability of the compensation point from the external edge to the center position within the edge compensation width is gradually increased. The shape of the printed image is obtained, the straight line type and the curved line type are identified along the edge of the shape of the printed image, and the number of compensation points at the curved line type position is greater than the number of compensation points at the straight line type position. The density, quantity, and generation probability of the compensation point within the edge compensation width are taken as the edge compensation gradient.

10. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the steps of the method of any one of claims 1 to 9.

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