A printing device ink intelligent prediction and adaptive color correction method and system

Abstract

This invention proposes a method and system for intelligent ink volume prediction and adaptive color correction in printing equipment. The method includes: acquiring image data of the page to be printed, performing region segmentation and neighborhood connectivity analysis to generate a structure-weighted effective ink density, and calculating a page-level ink volume prediction value in conjunction with a paper correction factor; mapping the ink volume prediction value and effective ink density to the printhead's basic jetting parameters and the scanning controller's structural constraint parameters; performing linear gain and nonlinear convergence processing on the original color channel values ​​based on the above parameters to generate corrected channel values; driving the printhead to print, and sampling the printed scanned tape using a linear optical acquisition unit; and performing residual compensation and convergence constraint correction on the execution values ​​of subsequent scanned tapes based on the difference between the measured values ​​and the target values. This invention can improve the consistency and accuracy of printed colors.

Description

Technical Field

[0001] This invention belongs to the field of printing control technology, and in particular relates to a method and system for intelligent ink volume prediction and adaptive color correction of printing equipment. Background Technology

[0002] With the widespread application of inkjet printers in office printing, advertising output, quick graphic printing, and packaging proofing, users' demands for print quality, color consistency, and ink utilization efficiency are constantly increasing. Current printing equipment typically estimates the required ink volume based on page coverage, paper type, or preset empirical parameters. While this method can meet general printing needs, it often fails to accurately reflect the impact of page content structure on actual ink delivery when dealing with complex pages such as mixed text and images, large blocks of photos, small text, QR codes, and inverted edges. In actual printing, the same coverage does not correspond to the same inkjet requirements. Continuous block areas and discrete text areas differ significantly in terms of jetting rhythm, ink density, and boundary preservation. If control is based solely on the overall page area or a fixed template, problems such as insufficient or excessive ink deposition in image areas, blurred text edges, dull dark areas, and overall color shift can easily occur. On the other hand, most existing color correction schemes focus on the static mapping of the input image to the device's color space, lacking the coordinated processing of page-level jet intensity, local structural constraints, and actual print result deviations. This results in ink volume control and color control being disconnected, making it difficult to simultaneously achieve ink conservation, clear boundaries, and overall color stability within the same control chain. Especially under the combined effects of paper absorption characteristics, page structure complexity, and continuous scanning execution conditions, cumulative deviations can occur between theoretical control values ​​and actual print results, making it difficult to correct subsequent scanned areas in a timely manner, ultimately affecting the overall page output quality. Therefore, a print control method is needed that unfolds step-by-step around page content structure, jet control, and print result verification, enabling a continuous connection between page-level ink volume requirements, printhead-level execution parameters, channel-level color output, and the actual printed result. This would improve ink volume control precision and print stability while ensuring color accuracy. Summary of the Invention

[0003] This invention discloses a method and system for intelligent ink volume prediction and adaptive color correction of printing equipment, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the first aspect of the present invention provides a method for intelligent ink volume prediction and adaptive color correction of a printing device, the method comprising: The image data of the page to be printed is acquired, and the image data is divided into regions and analyzed for neighbor connections to generate the effective ink density after structural weighting. Combined with the preset paper correction coefficient table, the page-level ink volume prediction value is calculated. The page-level ink volume prediction value and the structure-weighted effective ink density are mapped to the basic jetting parameters of the printhead and the structural constraint parameters of the scanning controller, wherein the basic jetting parameters are used to determine the basic jetting intensity, and the structural constraint parameters are used to adjust the switching between the continuous jetting segment and the boundary convergence segment. Based on the basic injection parameters and the structural constraint parameters, the input original color channel values ​​are subjected to linear gain and nonlinear convergence processing to generate corrected channel values. The printhead is driven to print according to the corrected channel values. During the printing process, the linear optical acquisition unit samples the printed scan strip. Based on the difference between the measured channel value and the target channel value obtained from the sampling, residual compensation and convergence constraint correction are performed on the execution value of the subsequent scan strip.

[0005] Further, the process of acquiring image data of the page to be printed, performing region segmentation and neighborhood connection analysis on the image data to generate a structure-weighted effective ink density, and calculating the page-level ink volume prediction value by combining it with a preset paper correction coefficient table, specifically includes: The image data is converted into a grayscale matrix, and the effective ink application area in the page is identified based on the background threshold. The entire image is divided into several sub-regions of a fixed size. The neighborhood connectivity of the effective ink pixels in each sub-region is counted. Different weights are assigned according to the continuity. The weighted summation is used to obtain the structurally weighted effective ink density. Based on the paper type in the printing task parameters, the corresponding correction coefficient is read from the paper correction coefficient table, and the effective ink density after structural weighting is multiplied by the correction coefficient to obtain the page-level ink volume prediction value.

[0006] Furthermore, the mapping of the page-level ink volume prediction value and the structure-weighted effective ink density to the printhead's basic jetting parameters and the scanning controller's structural constraint parameters specifically includes: Using the predicted page-level ink volume as a basis, a structural gain term determined by the effective ink density after structural weighting is introduced to calculate the basic jetting parameters. The basic jetting parameters are used to determine the jetting frequency setting and pulse width setting of the printhead. Using the structure-weighted effective ink density as the numerator, and introducing a difference suppression term determined by the difference between the page-level ink volume prediction value and the structure-weighted effective ink density as the denominator, the structure constraint parameters are calculated. These structure constraint parameters are used to adjust the local scheduling constraints of the scanning controller.

[0007] Furthermore, the step of performing linear gain and nonlinear convergence processing on the input raw color channel values ​​based on the basic injection parameters and the structural constraint parameters to generate corrected channel values ​​specifically includes: Based on the linear amplification factor of the spray intensity, the degree of suppression of structural continuity, and the saturation convergence factor obtained from the equipment calibration, a comprehensive color gain expression is constructed. Substitute the basic injection parameters and the structural constraint parameters into the comprehensive color gain expression to calculate the comprehensive color gain coefficient. The corrected channel value is calculated by multiplying the original color channel value by the comprehensive color gain coefficient as the numerator, and introducing the product of the square of the original color channel value and the basic injection parameter as the nonlinear convergence suppression term as the denominator.

[0008] Furthermore, the process of performing linear gain and nonlinear convergence processing on the input raw color channel values ​​to generate corrected channel values ​​specifically includes: In the low-value region, the influence of the nonlinear convergence suppression term is weak, and the corrected channel value is mainly enhanced by the linear gain term. In the high-value region, as the original color channel value increases, the influence of the nonlinear convergence suppression term strengthens, suppressing excessive superposition of the composite color and keeping the corrected channel value within a stable range.

[0009] Furthermore, the step of performing residual compensation and convergence constraint correction on the execution values ​​of subsequent scan bands based on the difference between the sampled measured channel values ​​and the target channel values ​​specifically includes: Establish a correction cost function that includes a residual compensation term and a convergence constraint term, wherein the residual compensation term is used to align the corrected execution value toward the ideal compensation target, and the convergence constraint term is used to limit the corrected value from deviating too much from the original target value; Minimize the correction cost function to calculate the optimal execution value for subsequent scan bands.

[0010] Furthermore, the calculation of the optimal execution value for subsequent scan bands specifically includes: When the measured channel value is less than the target channel value, a positive residual term is generated, which makes the optimal execution value of the subsequent scan band greater than the target channel value, thereby increasing the driving strength. When the measured channel value is greater than the target channel value, a negative residual term is generated, causing the optimal execution value of the subsequent scan band to be less than the target channel value, thereby reducing the driving intensity. The residual terms are controlled to converge using a preset convergence coefficient to prevent overshoot accumulation during continuous printing.

[0011] Furthermore, the sampling of the printed scan tape using a linear optical acquisition unit specifically includes: Using a linear optical acquisition unit arranged on the printhead carriage, point-by-point sampling is performed on the scan tape that has just been printed and has stabilized after a fixed time. After the sampled signal is converted from analog to digital, it is converted into the measured channel value within the same proportional range as the target channel value using the calibration lookup table established at the factory.

[0012] Furthermore, after performing residual compensation and convergence constraint correction on the execution values ​​of subsequent scan bands, the method further includes: The measured channel values ​​for each scan band are compared with the target printing results corresponding to the corrected execution values ​​to obtain the execution deviation; The execution deviation is averaged in units of scanning bands. If the average value exceeds a preset threshold, the equipment maintenance module is triggered to clean the nozzle or recalibrate it.

[0013] A second aspect of the present invention provides a printing device ink volume intelligent prediction and adaptive color correction system, the system comprising: The ink volume prediction module is used to acquire image data of the page to be printed, perform region division and neighborhood connection analysis on the image data, generate the effective ink density after structure weighting, and calculate the page-level ink volume prediction value by combining the preset paper correction coefficient table. The parameter generation module is used to map the page-level ink volume prediction value and the structure-weighted effective ink density to the basic jetting parameters of the printhead and the structural constraint parameters of the scanning controller, wherein the basic jetting parameters are used to determine the basic jetting intensity, and the structural constraint parameters are used to adjust the switching between the continuous jetting segment and the boundary convergence segment. The color correction module is used to perform linear gain and nonlinear convergence processing on the input raw color channel values ​​based on the basic spraying parameters and the structural constraint parameters, and generate corrected channel values. The execution correction module is used to drive the printhead to print according to the corrected channel values, and during the printing process, it uses a linear optical acquisition unit to sample the printed scan tape. Based on the difference between the measured channel value and the target channel value obtained from the sampling, it performs residual compensation and convergence constraint correction on the execution value of the subsequent scan tape.

[0014] The beneficial technical effects of the present invention are at least as follows: To address the aforementioned issues, this invention provides a method and system for intelligent ink volume prediction and adaptive color correction in printing equipment. It extracts the effective inking area and its spatial distribution characteristics from the image of the page to be printed, and combines this with the paper type to form a page-level ink volume prediction result. This allows ink volume estimation to move beyond simply calculating coverage and reflect the different needs of continuous image areas and discrete text areas in actual printing. Furthermore, it maps page-level ink volume requirements and structural characteristics to the printhead's basic jetting parameters and structural constraint parameters, enabling the equipment to distinguish between overall page ink intensity and local boundary preservation requirements before entering the execution phase. Subsequently, the jetting parameters are directly incorporated into the color channel correction calculation, allowing color output to adjust synchronously with jetting intensity and structural state, thereby improving overall color stability while suppressing excessive deposition in high-coverage areas. Finally, during actual printing, the output scanned tape is measured online, and the execution values ​​of subsequent scanned tapes are constrained and corrected based on the measurement results, ensuring that the control results continuously converge with the actual ink application state. In this way, the present invention constructs ink volume prediction, jet control, color correction and execution verification into a continuous printing control chain, so that there is a correspondence between page content structure, device output actions and final printing results, thereby simultaneously improving ink utilization efficiency, boundary clarity, overall color consistency and overall printing quality under complex page conditions. Attached Figure Description

[0015] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0016] Figure 1 This is a flowchart of a method for intelligent ink volume prediction and adaptive color correction in a printing device according to the present invention.

[0017] Figure 2 This is a framework diagram of an intelligent ink volume prediction and adaptive color correction system for a printing device according to the present invention. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In one or more embodiments, such as Figure 1 As shown, a method for intelligent ink volume prediction and adaptive color correction in printing devices is disclosed, the method comprising the following: S100: Acquire image data of the page to be printed, perform region division and neighborhood connection analysis on the image data, generate structure-weighted effective ink density, and calculate the page-level ink volume prediction value by combining the preset paper correction coefficient table. Specifically, after a print job enters the print queue, the image data of the page to be printed is read from the print service module of the operating system. This data is generated by the print driver after receiving the user's print command. It is typically a three-channel bitmap matrix, where each pixel position corresponds to a set of three-channel values ​​used to represent the page content. The image data is then converted via the print driver's internal color conversion interface. The image is converted to a grayscale matrix, and then the effective ink-bearing areas on the page are identified based on a background threshold preset during the equipment calibration phase. This background threshold is derived from the test results of standard blank pages during the equipment production phase and is used to distinguish between the content areas that actually participate in inkjet printing and the background areas. After extracting the effective ink-bearing areas, the entire page image is divided into several sub-regions of a fixed size, for example, 8×8 pixels. The neighborhood connectivity of the effective ink-bearing pixels in each sub-region is statistically analyzed: if adjacent pixels form a continuous distribution, the sub-region is considered to have high continuity; if the effective pixels appear scattered, the continuity is considered to be low. Based on this determination, different weights are assigned to each sub-region, and the results of all sub-regions are then weighted and summed to obtain the structure-weighted effective ink density. Here Calculated directly from the page image itself, it can simultaneously reflect the content coverage and spatial distribution. For example, with the same page coverage ratio, a full-page photo, due to its larger continuous area, yields... The text distribution will be higher than that in a regular document page, thus more closely reflecting the ink volume requirements in a real inkjet process.

[0020] In obtaining Next, the ink volume requirements are adjusted based on the paper type. The paper type is provided by the print job parameters, derived from the paper settings in the user's print interface, and transmitted to the print driver as parameters. The device has already completed standard test page printing for different types of paper at the factory, and the test results are compiled into a paper correction factor table. When executing the current job, the corresponding correction factor is read from this parameter table according to the paper type. Then, calculate the predicted ink volume for the current page using the following formula. : ; in, The ink volume prediction result for the current page will serve as the basis for subsequent printing parameter adjustments. The effective ink density, after structural weighting, is obtained from sub-region analysis of the page image; This is the correction factor corresponding to the paper type, obtained from the equipment parameter table. Taking a typical scenario as an example, if the structural density of an advertisement image on a certain page... After calculation, the result is higher than that of a regular text page. Furthermore, the current task uses paper with stronger ink absorption properties, so the retrieved data... It will also increase accordingly, and the final result will be The predicted values ​​will be higher than those for plain text pages, thus directly reflecting the combined impact of page content structure and paper variations on ink volume requirements. The final output is the predicted ink volume value. and structural density value ,in Used for subsequent printing parameter control. It continues to be used as a page structure feature in subsequent calculations.

[0021] S200: The page-level ink volume prediction value and the structure-weighted effective ink density are mapped to the basic jetting parameters of the printhead and the structural constraint parameters of the scanning controller, wherein the basic jetting parameters are used to determine the basic jetting intensity, and the structural constraint parameters are used to adjust the switching between the continuous jetting segment and the boundary convergence segment.

[0022] Specifically, the ink volume prediction value is obtained in step one. and structural density value After that, the control process enters the equipment parameter generation stage. At this time, This indicates the overall ink requirements of the page under the current paper conditions. These parameters represent the spatial continuity of the page content. Both have already been calculated from the image of the page to be printed in step one and written into the print control buffer as page-level parameters. After reading these two parameters, the print control board no longer re-analyzes the image but directly performs calculations focusing on "how to transform page-level requirements into printhead-level actions." Corresponding to the actual execution of the printing device, the controlled objects are mainly the jetting setting in the printhead drive register and the local scheduling coefficient in the scan controller. Therefore, this step generates two results around these two objects: basic jetting parameters. and structural constraint parameters .in, Determines the base spray intensity for this page during the scanning process. This determines the degree of local convergence when the page switches between continuous and boundary regions. After this processing, both quantities output from step one are fully received and continue to participate in device-level control.

[0023] Basic injection parameters Its structure originates from the classic proportional control concept. In engineering control, proportional control typically establishes an initial relationship by making the "control quantity proportional to the target quantity." In printing scenarios, the most direct target quantity is the total ink volume requirement of the page; therefore, it... The basis for the spray parameters conforms to the equipment control logic. Furthermore, considering that the spatial continuity of page content affects the actual spray rhythm of the printhead—for example, large-area images are more suitable for more stable continuous deposition, while text pages are more suitable for more restrained spray levels—a mechanism is introduced into the proportional control relationship based on… The determined structural gain term. Following this line of thought, first... As a basic proportional form, the structural influence is then written into the gain term to obtain the calculation formula for the basic injection parameters: ; in, This represents the basic jetting parameters, which are written into the printhead driver mapping table by the print control board to determine the jetting frequency level and pulse width level corresponding to the current page; This indicates that the predicted ink volume output from step one is obtained by combining the statistical results of the effective inked area of ​​the page to be printed with paper correction. The structural density value output from step one is obtained by dividing the page image into fixed sub-regions and performing continuous statistics. This represents the structural magnification factor, obtained through printing experiments on standard image pages, standard text pages, and mixed image / text pages during the equipment calibration phase, and is stored in the firmware parameter area. The derivation order of this formula is clear: first, the basic form is obtained through proportional control. Then, the page structure features are considered as a multiplicative correction to the basic injection parameters, forming... The gain term. Because the output of step one... and Since the parameters have already been processed into page-level parameters within the same proportional range during generation, multiplicative coupling here can directly reflect the combined effect of "overall ink volume requirement" and "structural continuity." According to this relationship, when there are many continuous blocks in the page image, Increase The corresponding improvement is made when the page mainly consists of discrete characters. Lower It maintains a more stable level. In printing scenarios, this calculation method can directly translate differences in page content into printhead settings, allowing advertising pages, photo pages, and text pages to have different basic printing strategies before entering the device for processing.

[0024] After obtaining the data, further local scheduling constraints are needed. While a high overall ink output intensity is required for the page, this doesn't mean all areas of the page are suitable for the same continuous printing rhythm. Common printing scenarios involving mixed text and graphics, fine-line graphics, and QR code pages present this situation: the overall ink demand is high, but local edge areas still require tighter control to maintain clear outlines and stable details. This constraint construction originates from the classic regularization concept, which introduces a suppression term in addition to the basic control variables to achieve a balance between global requirements and local stability. Here, we select... and The difference is used as the constraint object because This represents the total ink requirement for the page. Representing the degree of structural continuity, when the two match well, the page content and overall ink application trend are consistent, suitable for more stable continuous ink application; when the difference between the two increases, it often means that there are local boundary-sensitive areas or areas of text-image misalignment on the page, suitable for increasing convergence in the scheduling. Following this idea, structural density... By preserving the structural expression of the molecule and then introducing a differential suppression term into the denominator, the structural constraint parameters are obtained: ; in, These represent structural constraint parameters, which are read by the scanning controller and used to adjust the switching threshold between the continuous injection section and the boundary convergence section. This represents the structural density value output from step one; This represents the predicted ink volume output from step one; This represents the difference suppression coefficient, determined during the equipment calibration phase through comparative printing results of high-coverage pages, text-edge pages, and mixed-layout pages, and stored in the equipment parameter table. The derivation logic of this formula is consistent with the previous one: the previous formula first addresses "what basic spray intensity the page needs," while this formula addresses "how to maintain stability of this spray intensity in local areas." The denominator contains... The construction method derived from the squared error term, mathematically used to enhance sensitivity to deviations, translates in printing as follows: the greater the discrepancy between the total ink demand of the page and the structural continuity, the more crucial it is to converge local ink distribution to maintain clarity in edge and fine areas. and When they are close, the denominator is close to , When the difference is high, the scan controller executes in a more continuous manner; when the difference is large, the suppression term is enhanced. As the process progresses, the scanning controller triggers the convergence strategy earlier in the local area. This process uses the two page-level features from step one simultaneously for subsequent scheduling, enabling "total quantity" and "structure" to form a unified control chain during device execution.

[0025] In actual execution, the control flow unfolds in the following order: The print control board first reads the data from the cache. and Substitute into the above formula to calculate and Then, the nozzle mapping table and scan scheduling table in the device firmware are called. The mapping table pre-records different... The interval corresponds to the injection frequency setting, pulse width setting, and trigger density for each scan line; the scheduling table records different... The interval corresponds to the continuous spray segment length and local convergence threshold. After the control board completes the table lookup, it writes the corresponding results into the printhead drive register and scan control register. Subsequently, the printhead executes according to the parameters of that page during actual paper feeding and scanning. Corresponding to a specific page, the product image area on the promotional page will be affected by higher... To achieve a fuller, more rhythmic spray, the price text and QR code areas are... The constraints allow for faster convergence in the scan scheduling process, thus simultaneously ensuring the uniformity of large-area images and the clarity of small-area boundaries. Taking a set of page-level scaling parameters as an example, if step one outputs... , The corresponding structural amplification factor in the equipment parameter table is The difference inhibition coefficient is The basic injection parameters are then calculated as follows: ; This indicates that the current page should fall into a higher base spray level in the nozzle drive table. Substituting this into the formula for calculating the structural constraint parameters, we get: ; This demonstrates that the page utilizes a high overall spray intensity while maintaining strong structural expressiveness through localized adjustments. If the same... Corresponding to another page with a higher proportion of text, making If it drops to a lower level, then They will decrease simultaneously. This will also shift to a scheduling state that is more conducive to clear boundaries. Based on this calculation result, the control module looks up tables to generate register parameters, ultimately converting the page-level requirements identified in step one into nozzle-level actions that the device can execute. Finally, this step outputs the basic injection parameters. and structural constraint parameters .in, Used to determine the intensity of the base color deposition in subsequent color adjustment stages. The convergence method used for constraining local adjustments in subsequent stages ensures that the next step in color correction does not start from the page image again, but directly inherits the already completed spray-level control results.

[0026] S300: Based on the basic injection parameters and the structural constraint parameters, the input original color channel values ​​are subjected to linear gain and nonlinear convergence processing to generate corrected channel values.

[0027] Specifically, the basic injection parameters have already been obtained in step two. and structural constraint parameters These two quantities correspond to the basic spray intensity and local scheduling convergence of the page on the device, respectively, both determined by page-level parameters. and The derivation has been completed and written to the print control cache. In this step, the page content is no longer re-parsed; instead, pixel-by-pixel correction is performed directly on the color data stream output by the print driver to ensure stable color output under predetermined jetting conditions. The print driver converts the page to the device's color space, such as a CMYK four-channel data stream, before it enters the device. Each line of data is sent to the control module in scanning order, and each pixel corresponds to one or more channel values. Let the currently processed channel value be... This value comes directly from the raster data cache generated by the driver, and its range has been standardized by the device. When processing this data, the control module also reads page-level parameters. and And read three calibration coefficients from the equipment parameter table. , and These coefficients are all derived from standard color card printing experiments during the equipment's factory manufacturing phase: This represents the linear amplification factor of the effect of changes in jet intensity on the overall color deposition. This indicates the degree to which structural continuity inhibits boundary diffusion. This indicates the sedimentation convergence ability of highly saturated regions.

[0028] The fundamental principle of color deposition in inkjet printing can be approximated as a linear superposition process. That is, within the low-density range, the color channel output is directly proportional to the jetting volume. This relationship originates from a linear approximation model of optical density and ink droplet deposition volume. Based on this, the jetting intensity obtained in step two is introduced. As a scaling gain, the original channel value Magnification is performed to obtain the initial magnified form. ,in This represents the jetting enhancement term. Further considering the impact of page structure on the overall color deposition, the structural constraint parameters are... Introduced as a convergence factor, this factor originates from the modeling of the difference between page structure continuity and ink volume demand in step two. Its physical meaning is to maintain deposition stability in continuous regions and reduce diffusion tendencies in boundary regions. Therefore, this convergence term is written as... So that it can be in The inhibitory effect is enhanced at lower levels. At higher values, it approaches 1. Combining the two parts above, we obtain the comprehensive color gain expression: ; This expression is in the proportional control model. Based on this, an extended form is obtained by adding structural constraint adjustment terms, where This represents the overall color gain coefficient, used to describe the overall color change trend of the current page under given spraying conditions and structural features; This represents the basic injection parameters output in step two; This represents the structural constraint parameters output in step two; and These results were obtained from equipment calibration experiments. Because... , , , All of these are dimensionless proportional parameters, and the expression is a multiplicative structure, so the left and right sides of the equation maintain a consistent proportional relationship.

[0029] To achieve overall color gain Then, apply it to the original channel value. Preliminary correction results can be obtained. However, in actual printing, when It is relatively large and At higher values, simple linear amplification can easily lead to excessive color overlay, resulting in dullness in dark areas or localized ink buildup. Therefore, a suppression term is introduced based on the classic nonlinear convergence model. This model typically adopts the form of "output gradually converges as the input squares," meaning that a squared term is introduced into the denominator to enhance the suppression effect on high-value regions. Considering the printing scenario, this suppression term is constructed as follows: ,in Used to enhance sensitivity to high channel values. This is used to reflect the stronger convergence requirements under high injection intensity conditions. Here are the convergence coefficients obtained from experimental calibration. The final channel correction formula is: ; in, This represents the corrected channel output value, which is used to directly generate the nozzle drive signal; Indicates the original channel value; This refers to the overall color gain coefficient calculated in the previous step; Indicates the basic injection parameters; This represents the saturation convergence coefficient. This formula originates from a combined "linear gain + nonlinear convergence" model. Its derivation sequence is as follows: first, amplification is performed based on proportional relationships; then, high-value regions are suppressed using a squared convergence model, thus maintaining enhancement in low-value regions and preventing excessive growth in high-value regions. Since both the numerator and denominator are in proportional form, the overall result maintains dimensionless consistency.

[0030] In actual execution, the control module performs the above calculation pixel by pixel for each row of scan data. The specific process is as follows: read the channel value of the current pixel. Read page-level parameters from the cache and Read from the parameter table , , First calculate , then calculate and will Write to the nozzle driver cache. Then the nozzle driver circuit... The corresponding numerical values ​​generate drive pulses, for example, by controlling the pulse width or the number of pulses to achieve different ink droplet outputs. Because... and Maintaining consistency across the entire page, the calculation process can be executed continuously during scanning without affecting the device's real-time performance.

[0031] Taking a set of actual parameters as an example, let the original channel value of a certain pixel be... The page-level parameters obtained in step two are , The equipment calibration was obtained , , First, calculate the overall color gain: ; Then substitute the channel correction formula: ; The results indicate that the integrated color enhancement term first increases the channel deposition requirement, followed by the nonlinear convergence term suppressing the high-value region under high jet intensity, thus keeping the final output within a stable range. For this set of parameters, the convergence term has a stronger effect than the gain term; therefore, the calculated... Slightly lower than the original channel value This corresponds to the active convergence of potentially excessive deposition; for light-colored areas on the same page, due to The smaller the value, the weaker the influence of the convergence term in the denominator, and the channel value is closer to the result after gain adjustment; for dark regions, because... As the term increases, the convergence effect strengthens, thereby suppressing excessive superposition of the overall color. In this way, the spraying parameters obtained in step two are... and structural parameters This is further transformed into channel-level control results, achieving a seamless transition from page-level control to pixel-level color output. The final output is the corrected channel values. This value is directly used as the input of the printhead drive signal to participate in the actual printing execution, so that ink volume control, jet control and color control are completed in the same calculation chain.

[0032] S400: Drive the printhead to print according to the corrected channel value, and use the linear optical acquisition unit to sample the printed scan tape during the printing process. Based on the difference between the measured channel value and the target channel value obtained from the sampling, perform residual compensation and convergence constraint correction on the execution value of the subsequent scan tape.

[0033] Specifically, the corrected channel values ​​have already been obtained in step three. This value is the data foundation in the print control chain that actually drives the printhead. It integrates page content, ink volume, structural features, and jet control information into the same color output path. After entering this step, the control panel no longer remodels the page content; instead, it directly follows... The system generates printhead drive pulses and synchronously measures the area that has fallen onto the paper after the printhead finishes printing the current scan strip. Specifically, a set of linear optical acquisition units aligned with the printhead's movement direction is positioned on the printhead carriage at a fixed distance behind the nozzle array. These units move synchronously with the printhead carriage, sampling point-by-point the scan strip that has just finished printing and has stabilized after a fixed time. The sampled signals are converted from analog to digital and then sent to the control board, where they are further converted to digital form using a calibration lookup table established at the factory. Measured channel values ​​within the same scale range This lookup table was obtained through standard ribbon printing experiments: standard strips were printed at different channel values, and the corresponding optical sampling values ​​were recorded. Then, during equipment operation, the sampled signals were reconstructed into channel values ​​suitable for computation using a lookup table. Thus, This indicates "the target channel value that should have been printed". This indicates the "actual channel value that has been printed out," and the two can be directly compared within the same numerical space.

[0034] To ensure that subsequent scanned tapes, not yet printed, can be corrected based on the actual effect of the just-completed area, this step employs a "residual compensation plus convergence constraint" approach. This approach is based on the residual correction concept in engineering control: if the measured value of a printed area is lower than the target value, subsequent sections with the same color density should be compensated based on the original control value; if the measured value of an area is higher than the target value, subsequent sections should be converged in the opposite direction. Direct compensation based solely on residuals can easily lead to overshoot in areas with paper absorption fluctuations or text-image transitions. Therefore, a convergence constraint term from the classic regularization method is introduced to ensure that the correction both follows the measured deviation and maintains consistency with the target channel value given in step three. The continuity. Based on this idea, we first construct the correction cost: ; In the formula, This indicates the current scan band correction cost, used to describe the executed value after correction. The degree of overall deviation between the ideal compensation value and the original target value; This indicates that the corrected channel value with driver cache will be written to the subsequent scan; This indicates that the target channel value output in step three comes directly from the color correction result of the previous step; This indicates the measured channel value of the currently printed scan tape, which is measured by the linear optical acquisition unit and converted through calibration and table lookup. This represents the convergence coefficient, obtained through repeated printing on plain paper, coated paper, and high-coverage graphic pages during the equipment debugging phase. Its function is to control the degree to which the correction value retains the original target value. The first term of this formula originates from the idea of ​​one-step residual compensation, where... This indicates the ideal compensation target: when the measured value is lower than the target value, this item is higher. This indicates that the driving force should be increased subsequently; when the measured value is higher than the target value, this item is lower. The first term indicates that the drive should be reduced subsequently. The second term, derived from the classic Tikhonov regularization, is used to limit the correction value from deviating too much from the original target value, thereby keeping the correction process smooth. These two parts together determine that the correction in this step compensates in the opposite direction to the actual printing error while avoiding excessive correction at once.

[0035] In the above formula about Finding the minimum value yields the optimal execution value for subsequent scan bands. After differentiating and setting the derivative to zero, we get: ; In the formula, This indicates the corrected channel value, which the control board writes into the nozzle drive cache for the next scan band or the next scan pass; This represents the target channel value output in step three; This indicates the measured channel values ​​for the printed area; This represents the convergence coefficient. The derivation process is explicit: first, it starts with the cost... We establish a joint objective of "ideal compensation" and "stable convergence," and then obtain a unique solution through extreme value conditions. It can be directly seen from this formula that when... At that time, residual term For positive, Greater than This indicates that subsequent scan strips will automatically add drive; when hour, Less than This indicates that the subsequent scan band will automatically reduce the drive. This is because there is a [missing information] in the denominator. Therefore, this correction is always controlled and convergent, and overshoot accumulation will not occur during continuous printing. All quantities here use channel values ​​under the same proportional space, so the calculation remains consistent before and after, and can be directly mapped to the same gear system in the printhead drive table.

[0036] At the device execution level, after the control board completes the above calculations, it does not write back the area that has already been printed, but instead... Write to the line buffer of "subsequent scanned strips to be printed". Specifically, when the printhead carriage prints the current scanned strip... When scanning a strip, the rear optical acquisition unit measures the first... strip scan band The control board establishes a corresponding relationship based on the column position index within the scan band, so that the first... The measured value at a certain column position in the scanned strip corresponds one-to-one with the data of the same column position and the same color channel in the subsequent scanned strip to be printed, and then combined with the target value corresponding to that position. Calculate the correction value And write it to the driver cache of the corresponding column position in subsequent scans; for devices that use multiple scans, then... This is directly used in the next supplementary scan of the current area. Thus, the pixel-level target values ​​given in step three... In this step, the value is transformed into a "dynamically executable value that can be practically applied." The printing process itself includes three consecutive actions: measurement, correction, and re-execution. To ensure that this correction only applies to comparable areas, the control module establishes a position index on a per-scan-band basis, mapping segments with the same column position, same color channel, and similar color density within adjacent bands on the same page before proceeding. The update adapts to the continuous printing of different areas in the promotional page, such as large image areas, title color blocks, and small font text areas. This step is illustrated with a set of specific calculations. Let the target value for a certain channel be given in step three. The measured value obtained by the linear optical acquisition unit at the corresponding position in the previous scan band is The convergence coefficient determined during the debugging phase is First, calculate the ideal compensation target based on the residual compensation relationship. This indicates that if the residual is compensated exactly once, the subsequent driving value will increase to [a higher value]. Substituting this relationship back into the above formula, we obtain the corrected execution value: ; At this time, the control panel will Write to the driver cache of subsequent scans, instead of writing directly. The effect of this treatment is that subsequent areas will be improved in the direction of compensation, but the improvement rate remains stable, preventing over-absorption in the next scan band due to local differences in paper absorption. In continuous image areas on the same page, if multiple scan bands appear consecutively... Below In the case of... The brightness and saturation of the image will be gradually increased over several scans to bring the overall brightness and saturation closer to the target; in text boundaries and fine line areas, the color density changes between adjacent bands are more pronounced. and The differences are usually small, therefore The correction magnitude will naturally remain low, resulting in more stable edges.

[0037] After execution, the control board re-acquires the actual channel values ​​for each scan band and updates the corrected execution values. The corresponding target print result is compared with the actual test result to obtain the execution deviation of the scanned tape. Then, the execution deviation is averaged on a scanned tape basis as the process verification result for that page. A smaller average value indicates that the corrected actual print output is closer to the target channel value given in step three; a consistently larger average value indicates that the current paper condition or printhead condition has caused the print result to deviate from the target range, and the equipment maintenance module can trigger printhead cleaning or recalibration procedures accordingly. After this processing, this step outputs the value from step three. Converted into actual execution value The process verification results are obtained through online measurement, and finally fall into the actual execution path of "printing, correcting and verifying at the same time".

[0038] In one or more embodiments, such as Figure 2 As shown, a printing device ink volume intelligent prediction and adaptive color correction system is disclosed, the system comprising: The ink volume prediction module is used to acquire image data of the page to be printed, perform region division and neighborhood connection analysis on the image data, generate the effective ink density after structure weighting, and calculate the page-level ink volume prediction value by combining the preset paper correction coefficient table. The parameter generation module is used to map the page-level ink volume prediction value and the structure-weighted effective ink density to the basic jetting parameters of the printhead and the structural constraint parameters of the scanning controller, wherein the basic jetting parameters are used to determine the basic jetting intensity, and the structural constraint parameters are used to adjust the switching between the continuous jetting segment and the boundary convergence segment. The color correction module is used to perform linear gain and nonlinear convergence processing on the input raw color channel values ​​based on the basic spraying parameters and the structural constraint parameters, and generate corrected channel values. The execution correction module is used to drive the printhead to print according to the corrected channel values, and during the printing process, it uses a linear optical acquisition unit to sample the printed scan tape. Based on the difference between the measured channel value and the target channel value obtained from the sampling, it performs residual compensation and convergence constraint correction on the execution value of the subsequent scan tape.

[0039] It is worth noting that the specific workflow of the intelligent ink volume prediction and adaptive color correction system for printing equipment provided in this embodiment of the invention is the same as that of the intelligent ink volume prediction and adaptive color correction method for printing equipment described in the above embodiment, and will not be repeated here.

[0040] This invention also provides a printing device with intelligent ink volume prediction and adaptive color correction, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps described in the above embodiment of the printing device's intelligent ink volume prediction and adaptive color correction method, for example... Figure 1 The steps S1 to S4 described above; or, when the processor executes the computer program, it implements the functions of each module in the above system embodiments.

[0041] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for intelligent ink volume prediction and adaptive color correction in a printing device, characterized in that, The method includes: The image data of the page to be printed is acquired, and the image data is divided into regions and analyzed for neighbor connections to generate the effective ink density after structural weighting. Combined with the preset paper correction coefficient table, the page-level ink volume prediction value is calculated. The page-level ink volume prediction value and the structure-weighted effective ink density are mapped to the basic jetting parameters of the printhead and the structural constraint parameters of the scanning controller, wherein the basic jetting parameters are used to determine the basic jetting intensity, and the structural constraint parameters are used to adjust the switching between the continuous jetting segment and the boundary convergence segment. Based on the basic injection parameters and the structural constraint parameters, the input original color channel values ​​are subjected to linear gain and nonlinear convergence processing to generate corrected channel values. The printhead is driven to print according to the corrected channel values. During the printing process, the linear optical acquisition unit samples the printed scan strip. Based on the difference between the measured channel value and the target channel value obtained from the sampling, residual compensation and convergence constraint correction are performed on the execution value of the subsequent scan strip.

2. The intelligent ink volume prediction and adaptive color correction method for printing equipment according to claim 1, characterized in that, The process involves acquiring image data of the page to be printed, performing region segmentation and neighborhood connectivity analysis on the image data to generate a structure-weighted effective ink density, and calculating the predicted page-level ink volume using a preset paper correction factor table. Specifically, this includes: The image data is converted into a grayscale matrix, and the effective ink application area in the page is identified based on the background threshold. The entire image is divided into several sub-regions of a fixed size. The neighborhood connectivity of the effective ink pixels in each sub-region is counted. Different weights are assigned according to the continuity. The weighted summation is used to obtain the structurally weighted effective ink density. Based on the paper type in the printing task parameters, the corresponding correction coefficient is read from the paper correction coefficient table, and the effective ink density after structural weighting is multiplied by the correction coefficient to obtain the page-level ink volume prediction value.

3. The method of ink amount intelligent prediction and adaptive color correction for printing device according to claim 1, characterized in that, The mapping of the page-level ink volume prediction value and the structure-weighted effective ink density to the printhead's basic jetting parameters and the scanning controller's structural constraint parameters specifically includes: Using the predicted page-level ink volume as a basis, a structural gain term determined by the effective ink density after structural weighting is introduced to calculate the basic jetting parameters. The basic jetting parameters are used to determine the jetting frequency setting and pulse width setting of the printhead. Using the structure-weighted effective ink density as the numerator, and introducing a difference suppression term determined by the difference between the page-level ink volume prediction value and the structure-weighted effective ink density as the denominator, the structure constraint parameters are calculated. These structure constraint parameters are used to adjust the local scheduling constraints of the scanning controller.

4. The method of ink amount intelligent prediction and adaptive color correction for printing device according to claim 3, characterized in that, The process of performing linear gain and nonlinear convergence processing on the input raw color channel values ​​based on the basic injection parameters and the structural constraint parameters to generate corrected channel values ​​specifically includes: Based on the linear amplification factor of the spray intensity, the degree of suppression of structural continuity, and the saturation convergence factor obtained from the equipment calibration, a comprehensive color gain expression is constructed. Substitute the basic injection parameters and the structural constraint parameters into the comprehensive color gain expression to calculate the comprehensive color gain coefficient. The corrected channel value is calculated by multiplying the original color channel value by the comprehensive color gain coefficient as the numerator, and introducing the product of the square of the original color channel value and the basic injection parameter as the nonlinear convergence suppression term as the denominator.

5. The intelligent ink volume prediction and adaptive color correction method for printing equipment according to claim 4, characterized in that, The process of performing linear gain and nonlinear convergence processing on the input raw color channel values ​​to generate corrected channel values ​​specifically includes: In the low-value region, the influence of the nonlinear convergence suppression term is weak, and the corrected channel value is mainly enhanced by the linear gain term. In the high-value region, as the original color channel value increases, the influence of the nonlinear convergence suppression term strengthens, suppressing excessive superposition of the composite color and keeping the corrected channel value within a stable range.

6. The method of ink level intelligent prediction and adaptive color correction for printing device according to claim 1, characterized in that, The step of performing residual compensation and convergence constraint correction on the execution values ​​of subsequent scan bands based on the difference between the sampled measured channel values ​​and the target channel values ​​specifically includes: Establish a correction cost function that includes a residual compensation term and a convergence constraint term, wherein the residual compensation term is used to align the corrected execution value toward the ideal compensation target, and the convergence constraint term is used to limit the corrected value from deviating too much from the original target value; Minimize the correction cost function to calculate the optimal execution value for subsequent scan bands.

7. The intelligent ink volume prediction and adaptive color correction method for printing equipment according to claim 6, characterized in that, The calculation of the optimal execution value for subsequent scan bands specifically includes: When the measured channel value is less than the target channel value, a positive residual term is generated, which makes the optimal execution value of the subsequent scan band greater than the target channel value, thereby increasing the driving strength. When the measured channel value is greater than the target channel value, a negative residual term is generated, causing the optimal execution value of the subsequent scan band to be less than the target channel value, thereby reducing the driving intensity. The residual terms are controlled to converge using a preset convergence coefficient to prevent overshoot accumulation during continuous printing.

8. The intelligent ink volume prediction and adaptive color correction method for printing equipment according to claim 1, characterized in that, The sampling of the printed scan tape using a linear optical acquisition unit specifically includes: Using a linear optical acquisition unit arranged on the printhead carriage, point-by-point sampling is performed on the scan tape that has just been printed and has stabilized after a fixed time. After the sampled signal is converted from analog to digital, it is converted into the measured channel value within the same proportional range as the target channel value using the calibration lookup table established at the factory.

9. The intelligent ink volume prediction and adaptive color correction method for printing equipment according to claim 1, characterized in that, After performing residual compensation and convergence constraint correction on the execution values ​​of subsequent scan bands, the method further includes: The measured channel values ​​for each scan band are compared with the target printing results corresponding to the corrected execution values ​​to obtain the execution deviation; The execution deviation is averaged in units of scanning bands. If the average value exceeds a preset threshold, the equipment maintenance module is triggered to clean the nozzle or recalibrate it.

10. A printing device ink amount intelligent prediction and adaptive color correction system, characterized in that, The system includes: The ink volume prediction module is used to acquire image data of the page to be printed, perform region division and neighborhood connection analysis on the image data, generate the effective ink density after structure weighting, and calculate the page-level ink volume prediction value by combining the preset paper correction coefficient table. The parameter generation module is used to map the page-level ink volume prediction value and the structure-weighted effective ink density to the basic jetting parameters of the printhead and the structural constraint parameters of the scanning controller, wherein the basic jetting parameters are used to determine the basic jetting intensity, and the structural constraint parameters are used to adjust the switching between the continuous jetting segment and the boundary convergence segment. The color correction module is used to perform linear gain and nonlinear convergence processing on the input raw color channel values ​​based on the basic spraying parameters and the structural constraint parameters, and generate corrected channel values. The execution correction module is used to drive the printhead to print according to the corrected channel values, and during the printing process, it uses a linear optical acquisition unit to sample the printed scan tape. Based on the difference between the measured channel value and the target channel value obtained from the sampling, it performs residual compensation and convergence constraint correction on the execution value of the subsequent scan tape.

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