Large intelligent printing machine and printing correction method for large intelligent printing machine

Abstract

The invention provides a large-scale intelligent printing machine and a printing correction method for the large-scale intelligent printing machine. The method comprises the following steps: collecting reflected light intensities of different ink samples; performing feature conversion through the fluctuation features of the reflected light intensity of each ink sample to obtain a plurality of optical feature values, and performing division based on each optical feature value to obtain a plurality of printing color intervals; carrying out primary proportioning on the contents of various inks during printing to obtain a primary proportioning value of each ink; identifying a plurality of characteristic wave bands of the target printed matter, determining reference energy distribution under each characteristic wave band, determining a diffusion ratio according to all the reference energy distribution, and performing self-adaptive correction on the first-level matching values of various inks during printing through the diffusion ratio to obtain second-level matching values of the various inks; and controlling the ejection quantity of each type of ink according to each secondary matching value. By adopting the scheme of the invention, the optimal ink ratio of the target printed matter can be adjusted under the condition that the spectral reflection characteristic of the ink sample is changed.

Description

Technical Field

[0001] The present application relates to the field of industrial printing control technology, and more specifically, to a large-scale intelligent printing press and a printing correction method for the large-scale intelligent printing press. Background Art

[0002] Industrial printing control is a highly complex technology that integrates mechanics, electrical, computer image processing and automated control. Its core goal is to ensure that the color, pattern and material accuracy of the printing process meet strict quality standards while maximizing production efficiency. In order to achieve high-quality printing, the control system of industrial printing will accurately analyze the color and image before printing, and implement dynamic monitoring and adjustment during the printing process to ensure that every detail of industrial printing reaches the best level, thereby achieving high-quality and stable mass production.

[0003] Printing correction of large-scale intelligent printing machines is a crucial link in the industrial printing process. It aims to adjust printing parameters in real time through automation and intelligent means to ensure the stability and consistency of printing quality. This technology combines advanced intelligent sensors, real-time data analysis of machines and automated machine control systems, and can accurately adjust various variables in the industrial printing process, thereby significantly reducing color difference, improving printing accuracy, and adapting to changing production environments. In the existing printing correction technology of large-scale intelligent printing machines, after the printing color gamut composed of ink samples is divided into multiple subspaces, the distance between the target spectrum of the target printed object and the characteristic spectrum of each subspace is used to judge the subspace belonging of the target spectrum, and then the optimal ink ratio is solved based on the inverse solution of the characteristic band and the full band to achieve printing color difference correction. However, after various inks are mixed according to the optimal ink ratio obtained, the spectral reflectance characteristics of the ink sample will change, which will affect the accuracy of the characteristic band and cause color difference in intelligent printing. Therefore, how to adjust the optimal ink ratio of the target printed object when the spectral reflectance characteristics of the ink sample change has become a difficult problem faced by the industry. Summary of the invention

[0004] The present application provides a large-scale intelligent printing machine and a printing correction method for the large-scale intelligent printing machine, which can adjust the optimal ink ratio of a target printed object when the spectral reflection characteristics of an ink sample change.

[0005] In a first aspect, the present application provides a printing correction method for a large-scale intelligent printing machine, wherein the large-scale intelligent printing machine includes a sensing system, a control system, and a printing end effector, and the method includes the following steps:

[0006] The sensing system collects the reflected light intensity of different ink samples in each visible light band;

[0007] The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the optical characteristic values;

[0008] The control system also performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtains the primary matching ratio value of each ink;

[0009] The sensing system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all the reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing according to the diffusion ratio to obtain the secondary ratio values ​​of various inks;

[0010] The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

[0011] In some embodiments, the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands, and obtains a plurality of optical characteristic values, specifically including:

[0012] Determine the fluctuation characteristics of the reflected light intensity of various ink samples in all visible light bands;

[0013] Determine the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample according to the fluctuation characteristics corresponding to the various ink samples;

[0014] The fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical characteristic values ​​through the ratio of all light intensity fluctuations.

[0015] In some embodiments, dividing the printing color gamut formed by all ink samples into a plurality of printing color intervals based on the respective optical characteristic values ​​specifically includes:

[0016] Constructing color feature vectors of various ink samples based on the respective optical feature values;

[0017] Determining vector proximity between color feature vectors of various ink samples;

[0018] The printing color gamut formed by all ink samples is divided into multiple printing color intervals according to all vector approximations.

[0019] In some embodiments, the control system performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printed color interval, and obtains the primary matching ratio value of each ink specifically including:

[0020] Determine the center spectral vector of each printed color interval;

[0021] Obtaining a color spectrum vector of a target printed object;

[0022] Determine the spectral similarity between the color of the target printed object and each printed color interval according to the central spectral vector of each printed color interval and the color spectral vector of the target printed object;

[0023] Determine the optimal color range of the target print according to all spectral similarities;

[0024] Setting an optimal matching function for all inks based on the optimal color interval;

[0025] The optimal ratio function is used to determine the ratio of the contents of all inks during printing to obtain a primary ratio value of each ink.

[0026] In some embodiments, determining the reference energy distribution of reflected light in each characteristic band specifically includes:

[0027] Obtain the reflected light intensity of each ink in each characteristic band;

[0028] Determine the reflected composite light intensity of the target printed matter in each characteristic band according to the primary ratio value of each ink and the reflected light intensity of the ink in each characteristic band;

[0029] The reference energy distribution of the reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band.

[0030] In some embodiments, determining the diffusion ratio of the energy distribution after the ink is mixed according to all reference energy distributions specifically includes:

[0031] Determine the energy distribution diffusion model through all reference energy distributions;

[0032] The diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model.

[0033] In some embodiments, the primary ratio values ​​of various inks are adaptively corrected by the diffusion ratio during printing to obtain the secondary ratio values ​​of various inks, specifically including:

[0034] Obtaining a shifted characteristic band of the ink sample after the spectral reflectance characteristic is shifted;

[0035] Determine the compensation ratio value of each ink by using the diffusion ratio and the offset characteristic band;

[0036] Based on the compensation ratio value corresponding to each ink, the primary ratio value of the corresponding ink is adaptively corrected, so as to obtain the secondary ratio values ​​of various inks.

[0037] In a second aspect, the present application provides a large-scale intelligent printing machine, including a sensing system, a control system, and a printing end effector, wherein

[0038] The sensing system collects the reflected light intensity of different ink samples in each visible light band;

[0039] The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the optical characteristic values;

[0040] The control system also performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtains the primary matching ratio value of each ink;

[0041] The sensing system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all the reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing according to the diffusion ratio to obtain the secondary ratio values ​​of various inks;

[0042] The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

[0043] In a third aspect, the present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned printing correction method for a large-scale intelligent printing press when executing the computer program.

[0044] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-mentioned printing correction method for a large-scale intelligent printing press.

[0045] The technical solution provided by the embodiments disclosed in this application has the following beneficial effects:

[0046] In the large-scale intelligent printing machine and the printing correction method for the large-scale intelligent printing machine provided by the present application, the perception system collects the reflected light intensity of different ink samples in each visible light band; the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensity of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut composed of all ink samples into multiple printing color intervals based on each optical characteristic value; the control system also performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval to obtain the primary matching ratio value of each ink; the perception system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all reference energy distributions, and adaptively corrects the primary matching ratio values ​​of various inks during printing through the diffusion ratio to obtain the secondary matching ratio values ​​of various inks; the printing end effector controls the injection amount of each ink according to each secondary matching ratio value.

[0047] It can be seen that in the present application, first, after collecting the reflected light intensity of different ink samples in each visible light band, a plurality of printing color intervals are divided based on the reflected light intensity corresponding to each ink sample, and then, the primary matching ratio value of each ink when printing the target printed object is determined according to the spectral similarity between the color of the target printed object and each printing color interval, the inks are mixed according to all the primary matching ratio values, and then, the positions of those wavelengths that best represent the color characteristics, differences or changes in the spectral data of the target printed object are identified, that is, the characteristic bands, and then, in each characteristic band, the comparison between the actual reflected light intensity of the target printed object and the reflected synthetic light intensity generated by the mixing of the inks is determined, that is, the reference energy distribution, and then the color performance after the ink mixing is determined according to all the reference energy distributions. The difference between the colors of the target printed objects, namely: the diffusion ratio. Finally, the primary ratio values ​​of various inks during intelligent printing are adaptively corrected by the diffusion ratio to obtain the secondary ratio values ​​of various inks; the ejection amount of each ink in the special intelligent printing machine is controlled according to each secondary ratio value; the present application uses the difference between the actual reflected light intensity of the target printed object and the reflected synthetic light intensity generated by the ink mixing as a reference (reference energy distribution), thereby judging the difference between the color performance after the ink mixing and the color of the target printed object (diffusion ratio), and then adjusting the ejection amount of each ink in the large-scale intelligent printing machine according to the degree of difference; in summary, the present application can adjust the optimal ink ratio of the target printed object when the spectral reflectance characteristics of the ink sample change. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1is a flow chart of a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application;

[0049] Figure 2 is a schematic diagram of a process for dividing printing color intervals according to some embodiments of the present application;

[0050] Figure 3 is a schematic diagram of a process for determining a reference energy distribution according to some embodiments of the present application;

[0051] Figure 4 is a schematic diagram of the structure of a large-scale intelligent printing machine according to some embodiments of the present application;

[0052] Figure 5 It is a diagram of the internal structure of a computer device for implementing a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application. DETAILED DESCRIPTION

[0053] In order to better understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0054] refer to Figure 1 , which is a flow chart of a printing correction method for a large-scale intelligent printing machine according to some embodiments of the present application. The printing correction method 100 for a large-scale intelligent printing machine mainly includes the following steps:

[0055] In step 101, the sensing system collects the reflected light intensity of different ink samples in each visible light band.

[0056] In specific implementation, the ink can be mixed with a transparent diluent in a specific ratio (for example, 0.1, 0.2, 0.3, 0.4, 0.5) to obtain ink samples with different ratios, and the mixed ink samples can be evenly coated on a standardized sample plate or paper to ensure that the thickness of the coating is consistent. Then, light of a predetermined band (multiple visible light bands) is emitted through a sensing system, and the light intensity reflected by the ink sample is measured to obtain the reflected light intensity of the ink sample in each visible light band under different ratios.

[0057] It should be noted that the perception system described in the present application may use a spectrophotometer, which has a stable light source, usually a tungsten halogen lamp or a xenon lamp, and can emit all bands of the visible light range (380nm to 780nm). When measuring the reflected light intensity, the spectrophotometer uses the different structures of ink samples under different ratios and their different absorption capabilities for light of different bands, that is, by separating each monochromatic light from the mixed light containing various wavelengths and measuring its intensity, the reflected light intensity of the ink sample can be obtained.

[0058] In step 102, the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut composed of all ink samples into multiple printing color intervals based on the optical characteristic values.

[0059] It should be noted that the ink sample has a corresponding reflected light intensity in each visible light band, that is, one ink sample corresponds to multiple reflected light intensities. Therefore, in some embodiments, the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands, and obtaining multiple optical characteristic values ​​can be achieved by the following steps:

[0060] Determine the fluctuation characteristics of the reflected light intensity of various ink samples in all visible light bands;

[0061] Determine the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample according to the fluctuation characteristics corresponding to the various ink samples;

[0062] The fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical characteristic values ​​through the ratio of all light intensity fluctuations.

[0063] It should be noted that the fluctuation characteristic represents the fluctuation amplitude of the light intensity of the ink sample in the visible light band as the wavelength changes, reflecting the variability of the reflected light intensity of the corresponding ink sample at different wavelengths. The larger the fluctuation characteristic, the higher the variability of the reflected light intensity of the corresponding ink sample at different wavelengths, which means that the greater the change in the reflected light intensity of the ink sample at different wavelengths, the less smooth the spectral reflection curve. The smaller the fluctuation characteristic, the lower the variability of the reflected light intensity of the corresponding ink sample at different wavelengths, indicating that the spectral reflection curve of the corresponding ink sample is relatively smooth and the change in reflected light intensity at different wavelengths is small. In specific implementation, the fluctuation characteristics of the reflected light intensity of various ink samples in all visible light bands can be determined in the following way, namely: the standard deviation of all reflected light intensities corresponding to various ink samples is used as the fluctuation characteristic of the reflected light intensity of the ink sample in all visible light bands. In other embodiments, it can also be determined by other methods, which are not limited here.

[0064] In specific implementation, the intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample is determined according to the fluctuation characteristics corresponding to various ink samples, which can be achieved in the following manner, namely: first, an ink sample is selected as the selected ink sample, and then, the average value of the reflected light intensity corresponding to the selected ink sample is determined; secondly, a reflected light intensity is selected, and the reflected light intensity is subtracted from the average value and divided by the value of the fluctuation characteristic as the intensity fluctuation ratio of the reflected light intensity; the above steps are repeated to determine the intensity fluctuation ratios of the remaining reflected light intensities, thereby obtaining the intensity fluctuation ratio of each reflected light intensity corresponding to the selected ink sample, and the intensity fluctuation ratios of the reflected light intensities corresponding to the remaining ink samples are continued to be determined.

[0065] It should be noted that the light intensity fluctuation ratio described in the present application represents the degree of deviation of the corresponding reflected light intensity from the average reflected light intensity, and is used to quantitatively evaluate the deviation of the reflected light intensity of the ink sample in a specific band from its overall performance. The larger the light intensity fluctuation ratio, the higher the degree of deviation of the corresponding reflected light intensity from the average reflected light intensity, and the smaller the light intensity fluctuation ratio, the lower the degree of deviation of the corresponding reflected light intensity from the average reflected light intensity.

[0066] In specific implementation, the following method can be used to convert the fluctuation characteristics of each ink sample in all visible light bands into multiple optical eigenvalues ​​through all light intensity fluctuation ratios, namely: first, all light intensity fluctuation ratios corresponding to various ink samples are combined into a light intensity fluctuation matrix, and then the covariance matrix of the light intensity fluctuation matrix is ​​determined. Secondly, the eigenvalue decomposition algorithm in the prior art is used to perform eigenvalue decomposition on the covariance matrix to obtain multiple eigenvalues ​​and eigenvectors corresponding to each eigenvalue, and all eigenvalues ​​are used as optical eigenvalues ​​in this application, thereby obtaining multiple optical eigenvalues. In other embodiments, other methods can also be used for determination, which is not limited here. In addition, it should be noted that the optical eigenvalue is the main feature of the corresponding ink sample, which characterizes the contribution of the main feature to the reflected light intensity of all ink samples. The larger the optical eigenvalue, the higher the contribution of the main feature to the reflected light intensity of all ink samples, and the smaller the optical eigenvalue, the lower the contribution of the main feature to the reflected light intensity of all ink samples.

[0067] In some embodiments, reference Figure 2 As shown, this figure is a schematic diagram of the process of dividing the printing color intervals shown in some embodiments of the present application. The printing color gamut composed of all ink samples is divided into multiple printing color intervals based on each optical characteristic value, which can be achieved by using the following steps:

[0068] First, in 1021, color feature vectors of various ink samples are constructed based on the respective optical feature values;

[0069] Then, in 1022, the vector closeness between the color feature vectors of various ink samples is determined;

[0070] Finally, in 1023, the printing color gamut formed by all ink samples is divided into a plurality of printing color intervals according to all vector approximations.

[0071] It should be noted that, in the present application, when determining the optical characteristic value, each optical characteristic value has a unique corresponding characteristic vector. Therefore, in the specific implementation, the color characteristic vectors of various ink samples constructed based on each optical characteristic value can be implemented in the following manner: first, the first two largest optical characteristic values ​​are obtained from all optical characteristic values, and then the characteristic vectors corresponding to the two optical characteristic values ​​are obtained, and the elements in the two characteristic vectors are used as a column in the matrix to form a characteristic vector matrix. Subsequently, the characteristic vector matrix and the light intensity fluctuation matrix are multiplied to obtain a color characteristic matrix. Finally, the vector composed of the matrix elements of each row in the color characteristic matrix is ​​used as the color characteristic vector of the corresponding ink sample, thereby obtaining the color characteristic vectors of various ink samples. In other embodiments, other methods can be used for determination, which is not limited here. In addition, as a preferred embodiment, the vector approximation between the color characteristic vectors of various ink samples can be determined in the following manner, namely: the cosine similarity between vectors in the prior art is used as the vector approximation between the color characteristic vectors of various ink samples in the present application, thereby obtaining the vector approximation between the color characteristic vectors of various ink samples. In other embodiments, other methods can be used for determination, which is not repeated here.

[0072] It should be noted that the color feature vector is a mathematical representation of the spectral reflectance characteristics of the ink sample after eigenvalue decomposition, which contains the color information of the ink sample and reflects the main color change trend of the ink sample under different spectral characteristics. The larger the vector element in the color feature vector, the more significant the performance of the ink sample in a specific optical feature dimension (such as color, reflectivity, etc.), and the smaller the vector element in the color feature vector, the less significant the performance of the ink sample in a specific optical feature dimension (such as color, reflectivity, etc.); in addition, the vector closeness characterizes the color similarity of the two corresponding ink samples. The larger the vector closeness, the higher the color similarity of the two corresponding ink samples, and the smaller the vector closeness, the lower the color similarity of the two corresponding ink samples.

[0073] In specific implementation, the following method can be used to divide the printing color gamut composed of all ink samples into multiple printing color intervals based on all vector proximity, namely: first, all vector proximity is used as the similarity index between every two ink samples, then, all vector proximity is used as input, and the K-means clustering algorithm in the prior art is used to classify all ink samples into multiple ink sample clusters, and then, the printing color gamut composed of all ink samples is obtained. Finally, an ink sample cluster is selected to obtain the color intervals represented by various ink samples in the printing color gamut in the ink sample cluster, and the union of all color intervals is used as the printing color interval corresponding to the ink sample cluster. The above steps are repeated to determine the printing color intervals corresponding to the remaining ink sample clusters, thereby dividing the printing color gamut composed of all ink samples into multiple printing color intervals. In other embodiments, other methods can also be used for determination, which are not limited here.

[0074] It should be noted that the printing color interval refers to the color range that the corresponding ink sample cluster can express in the printing color gamut composed of all ink samples. The larger the printing color interval, the wider the color variation that the ink sample cluster can express, that is, it has better mixing ability and can cover more printing colors. The smaller the printing color interval, the limited color range that the ink sample cluster expresses, that is, it is used for more specific color scenes.

[0075] In step 103, the control system also performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtains the primary matching ratio value of each ink.

[0076] In some embodiments, the control system performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printed color interval, and obtains the primary matching value of each ink by the following steps:

[0077] Determine the center spectral vector of each printed color interval;

[0078] Obtaining a color spectrum vector of a target printed object;

[0079] Determine the spectral similarity between the color of the target printed object and each printed color interval according to the central spectral vector of each printed color interval and the color spectral vector of the target printed object;

[0080] Determine the optimal color range of the target print according to all spectral similarities;

[0081] Setting an optimal matching function for all inks based on the optimal color interval;

[0082] The optimal ratio function is used to determine the ratio of the contents of all inks during printing to obtain a primary ratio value of each ink.

[0083] It should be noted that the central spectral vector described in the present application represents the representative spectral distribution of the printed color interval, and characterizes the reflection characteristics of the corresponding color interval in different bands; in specific implementation, the central spectral vector of each printed color interval can be determined in the following manner, namely: first, a printed color interval is selected, and then, a plurality of ink samples corresponding to the printed color interval are obtained, and each spectral value in the spectral data of the various ink samples is sorted in the order of the size of the corresponding band to form the spectral vectors of the various ink samples; secondly, a band is selected, and the spectral values ​​of the various ink samples in the band are obtained, and the average value of the spectral values ​​of the various ink samples in the band is used as the central spectral value of the printed color interval in the band, and the above steps are repeated to determine the central spectral value of the printed color interval in the remaining bands; finally, all the central spectral values ​​are sorted in the order of the size of the corresponding bands as vector elements, thereby obtaining the central spectral vector of the printed color interval, and the above steps are repeated to determine the central spectral vector of the remaining printed color intervals.

[0084] It should be noted that, in the present application, after measuring the reflected light intensity of the target printed matter in each visible light band by a spectrophotometer, a vector composed of all reflected light intensities sorted according to the size of the corresponding band is used as the color spectrum vector of the target printed matter. In other embodiments, other methods can also be used to determine it, which is not limited here.

[0085] In specific implementation, determining the spectral similarity between the color of the target printed object and each printed color interval based on the central spectral vector of each printed color interval and the color spectral vector of the target printed object can be achieved in the following manner, namely: first, selecting a printed color interval as the selected printed color interval, then obtaining the central spectral vector of the printed color interval, and secondly, determining the square of the difference between the spectral values ​​of the central spectral vector and the color spectral vector in each band, and then adding the results corresponding to each band and taking the square root as the spectral similarity between the color of the target printed object and the selected printed color interval, and continuing to determine the spectral similarity between the color of the target printed object and the remaining printed color intervals; as a preferred embodiment, determining the optimal color interval of the target printed object based on all spectral similarities can be achieved in the following manner, namely: taking the printed color interval with the greatest spectral similarity to the color of the target printed object as the optimal color interval of the target printed object, and in other embodiments, other methods can also be used for determination, which are not limited here.

[0086] It should be noted that the spectral similarity reflects the degree of similarity between the color spectrum vector of the target printed object and the central spectrum vector of the corresponding printed color interval. The greater the spectral similarity, the higher the degree of similarity between the color spectrum vector of the target printed object and the central spectrum vector of the corresponding printed color interval. The smaller the spectral similarity, the lower the degree of similarity between the color spectrum vector of the target printed object and the central spectrum vector of the corresponding printed color interval.

[0087] In specific implementation, the optimal matching function for all inks is set based on the optimal color interval and can be implemented in the following manner, namely: the objective function of minimizing the difference between the spectral vector after the ink samples are mixed and the central spectral vector of the optimal color interval is used as the optimal matching function in the present application. As a preferred embodiment, the error function that minimizes the sum of squares of errors between the target spectrum and the mixed spectra of all inks can be used as the optimal matching function in the present application. In other embodiments, other methods can also be used to determine it, which is not limited here. In addition, as a preferred embodiment, the content of all inks is determined to be matched during printing through the optimal matching function to obtain the primary matching value of each ink. It can be implemented in the following manner, namely: after derivation of the optimal matching function and setting the derivative result to 0, the closed-form solution of the least squares method in the prior art is used to solve the matching values ​​corresponding to various inks when the difference between the spectral vector after the ink samples are mixed and the central spectral vector of the optimal color interval is minimized, and the matching values ​​corresponding to various inks are used as the primary matching values ​​of the corresponding inks during printing, thereby obtaining the primary matching value of each ink. In other embodiments, other methods can also be used to determine it, which is not limited here.

[0088] It should be noted that the optimal matching function is an objective function for calculating the mixing ratio of all ink samples. The goal of the optimal matching function is to make the spectral vector of the mixed ink samples match the central spectral vector of the optimal color interval as much as possible, that is, to minimize the spectral difference between the two. By optimizing the optimal matching function, the present application can determine the best ink matching ratio, thereby achieving a result that is closest to the target printed color. In addition, the primary matching ratio value is the content ratio of various inks that should be used in the printing process calculated based on the optimal matching function. The larger the primary matching ratio value, the higher the content ratio of the corresponding ink that should be used in the printing process, and the smaller the primary matching ratio value, the lower the content ratio of the corresponding ink that should be used in the printing process.

[0089] In step 104, the perception system automatically identifies multiple characteristic bands of reflected light when the target printed material is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing through the diffusion ratio to obtain the secondary ratio values ​​of various inks.

[0090] In specific implementation, the characteristic band refers to the position of those wavelengths that best represent the color characteristics, differences or changes in the spectral data of the target print. In some preferred embodiments, after the spectral data of the target print is formed into a spectral curve, the bands corresponding to the inflection points of the spectral curve (i.e., the positions where the slope of the curve changes the most) are obtained as multiple characteristic bands of the target print, thereby automatically identifying multiple characteristic bands of reflected light when the target print is printed. In other embodiments, other methods can be used to determine, which are not limited here. In addition, the characteristic band belongs to the visible light band, that is, each ink has a unique corresponding reflected light intensity under the characteristic band.

[0091] In some embodiments, reference Figure 3 As shown, this figure is a schematic diagram of the process of determining the reference energy distribution shown in some embodiments of the present application. The reference energy distribution of the reflected light in each characteristic band can be determined by the following steps:

[0092] First, in 1041, the reflected light intensity of each ink in each characteristic band is obtained;

[0093] Then, in 1042, the reflected composite light intensity of the target printed object in each characteristic band is determined according to the primary ratio value of each ink and the reflected light intensity of the ink in each characteristic band;

[0094] Finally, in 1043, the reference energy distribution of the reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band.

[0095] It should be noted that the reflected composite light intensity described in the present application represents the overall reflected light intensity of the target printed object after a plurality of inks are mixed with corresponding primary matching ratio values ​​in each characteristic band; as a preferred embodiment, the reflected composite light intensity of the target printed object in each characteristic band is determined according to the primary matching ratio value of each ink and the reflected light intensity of the ink in each characteristic band. This can be achieved in the following manner, namely: first, a characteristic band is selected as the selected characteristic band, and then, the reflected light intensity of various inks in the selected characteristic band is multiplied by the primary matching ratio value of the corresponding ink, and the result of adding the corresponding results of all inks is taken as the reflected composite light intensity of the target printed object in the selected characteristic band, and the reflected composite light intensity of the target printed object in the remaining characteristic bands is continued to be determined.

[0096] In specific implementation, the reference energy distribution of reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band. The following method is adopted, namely: first, the reflected light intensity of the target printed object in each characteristic band is obtained, and then a characteristic band is selected as the selected characteristic band, and the difference between the reflected light intensity of the target printed object in the selected characteristic band and the reflected composite light intensity of the target printed object in the selected characteristic band is determined, and the result obtained by taking the negative value of the logarithm with base 10 of the obtained result is determined, and the obtained result is used as the reference energy distribution of the reflected light of the target printed object in the selected characteristic band, and the reference energy distribution of the reflected light of the target printed object in the remaining characteristic bands is continued to be determined.

[0097] It should be noted that the reference energy distribution in the present application is based on the comparison between the actual reflected light intensity of the target print and the reflected synthetic light intensity generated after the ink is mixed. The present application uses the difference between the actual reflected light intensity of the target print and the reflected synthetic light intensity generated after the ink is mixed as a reference to judge the degree of adjustment of the ratio values ​​of various ink samples. The larger the reference energy distribution, the greater the difference between the actual reflected light intensity of the target print and the expected reflected synthetic light intensity, that is, the ink ratio in the characteristic band does not meet the actual needs and needs further adjustment. The smaller the reference energy distribution, the smaller the difference between the actual reflected light intensity of the target print and the expected reflected synthetic light intensity, that is, the current ratio is relatively reasonable and the performance of the target print in this band is consistent with expectations.

[0098] In some embodiments, determining the diffusion ratio of the energy distribution after ink mixing according to all reference energy distributions can be achieved by the following steps:

[0099] Determine the energy distribution diffusion model through all reference energy distributions;

[0100] The diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model.

[0101] In specific implementation, the energy distribution diffusion model determined by all reference energy distributions can be implemented in the following manner, namely: first, after setting the intercept parameter and the slope parameter, according to the linear regression model in the prior art, a characteristic band is selected as the selected characteristic band, and the reflected light intensity of various inks in the selected characteristic band is obtained, and the logarithm of the reflected light intensity corresponding to various inks with a base of 10 is determined and then multiplied by the negative result of the quotient of the slope parameter and the corresponding primary matching ratio value, and the result after adding the results corresponding to various inks is equal to the reference energy distribution corresponding to the selected characteristic band, and the equations corresponding to the remaining characteristic bands are continuously constructed, so that the model composed of all the equations is used as the energy distribution diffusion model in this application. In other embodiments, other methods may be used for determination, which are not limited here. In addition, as a preferred embodiment, the diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model, which can be achieved in the following manner, namely: first, the mean square error of the result obtained by fitting the reference energy distribution corresponding to each characteristic band with the energy distribution diffusion model is minimized, and then an objective function is constructed. Then, the derivative of the objective function with respect to the slope parameter is calculated, and after setting the derivative to zero, the optimal slope parameter is solved to obtain the optimal slope parameter, and the optimal slope parameter is used as the diffusion ratio of the energy distribution after ink mixing in this application. In other embodiments, other methods may be used for determination, which are not described here.

[0102] It should be noted that the energy distribution diffusion model described in the present application describes how the energy distribution of inks diffuses over time or over changing conditions after they are mixed during the printing process. The present application uses the energy distribution diffusion model to consider changes in reflected light intensity in different characteristic bands, thereby realizing the prediction of the optical properties of the final printed product. In addition, the diffusion ratio of the energy distribution after the inks are mixed is a descriptive quantity of the degree of diffusion of the energy distribution in each characteristic band after the inks are mixed. The larger the diffusion ratio, the stronger the interaction between different inks in terms of reflected light intensity, resulting in greater differences in the colors after mixing, i.e., a higher degree of diffusion. The smaller the diffusion ratio, the smaller the change in the optical properties of the inks, the better the mixing effect, and the closer the reflected light intensity is to expectations, i.e., a lower degree of diffusion.

[0103] In some embodiments, the primary ratio values ​​of various inks are adaptively corrected by the diffusion ratio during printing to obtain the secondary ratio values ​​of various inks, which can be achieved by the following steps:

[0104] Obtaining a shifted characteristic band of the ink sample after the spectral reflectance characteristic is shifted;

[0105] Determine the compensation ratio value of each ink by using the diffusion ratio and the offset characteristic band;

[0106] Based on the compensation ratio value corresponding to each ink, the primary ratio value of the corresponding ink is adaptively corrected, so as to obtain the secondary ratio values ​​of various inks.

[0107] In specific implementation, the shifted characteristic band of the spectral reflectance characteristics of the ink sample after the shift can be obtained by measuring the ink sample after being proportioned according to all the primary proportioning values ​​through a spectrum analyzer, so as to obtain the band position in the spectral data of the ink sample that best represents the color characteristics, differences or changes. In some preferred embodiments, after the spectral data of the ink sample is formed into a spectral curve, the band corresponding to the inflection point of the spectral curve (i.e., the position where the slope of the curve changes the most) is obtained as the shifted characteristic band of the ink sample. In other embodiments, other methods can be used to determine, which are not limited here.

[0108] In some embodiments, determining the compensation ratio value of each ink by using the diffusion ratio and the offset characteristic band can be achieved in the following manner:

[0109] Acquire the offset reflected light intensity of the ink sample in the offset characteristic band;

[0110] Determining the offset energy distribution of the ink sample in the offset characteristic band based on the reflected composite light intensity of the ink sample;

[0111] The compensation ratio value of each ink is determined by the offset energy distribution and the diffusion ratio.

[0112] Preferably, the offset reflected light intensity of the ink sample in the offset characteristic band can be measured by a spectrophotometer. It should be noted that the offset characteristic band is the band position that best represents the color characteristics, differences or changes of the ink sample after the spectral reflectance characteristics of the ink sample change due to the mixing of various inks. The offset reflected light intensity is: the reflected light intensity of the mixed ink sample in the offset characteristic band.

[0113] It should be noted that the compensation ratio value, that is, the additional ink ratio calculated to correct the color deviation on the offset characteristic band, is used to correct the primary ratio value. The present application compensates for the printing deviation caused by color offset by reflecting the difference in reflection intensity on the offset characteristic band. In specific implementation, the offset energy distribution of the ink sample on the offset characteristic band is determined based on the reflected synthetic light intensity of the ink sample, which can be achieved in the following manner, namely, first, the difference between the offset reflected light intensity and the reflected synthetic light intensity is determined, and secondly, the result obtained is taken as the negative value of the logarithm with base 10 as the offset energy distribution of the ink sample on the offset characteristic band. In addition, as a preferred embodiment, the compensation ratio value of each ink is determined by the offset energy distribution and the diffusion ratio, which can be achieved in the following manner, namely, after taking the offset energy distribution and the diffusion ratio as inputs of the energy distribution diffusion model, the model equation is solved, and the result obtained is used as the compensation ratio value of the corresponding ink. In other embodiments, other methods can also be used for determination, which are not limited here.

[0114] In specific implementation, the primary ratio value of the corresponding ink is adaptively corrected based on the compensation ratio value corresponding to each ink, so as to obtain the secondary ratio values ​​of various inks. This can be achieved in the following way, namely: first, one ink is selected as the selected ink, and then, the primary ratio value of the selected ink and the compensation ratio value corresponding to the selected ink are added together as the secondary ratio value of the selected ink, and the secondary ratio values ​​of the remaining inks are further determined.

[0115] In step 105, the printing end effector controls the ejection amount of each ink according to each secondary ratio value.

[0116] It should be noted that when the printing end effector described in the present application includes a flow control valve, the printing end effector controls the injection amount of each ink according to each secondary ratio value in the following manner, namely: first, a precise flow control valve is installed on each nozzle of the large-scale intelligent printing machine to adjust the injection amount of each ink, and then, the opening and closing degree of the flow control valve of the corresponding nozzle is regulated according to the secondary ratio value corresponding to each ink. For example, the larger the secondary ratio value, the higher the opening and closing degree of the flow control valve of the nozzle of the corresponding ink, and the smaller the secondary ratio value, the lower the opening and closing degree of the flow control valve of the nozzle of the corresponding ink; thereby controlling the injection amount of each ink in the large-scale intelligent printing machine. In other embodiments, it can also be regulated by other methods, which are not limited here.

[0117] It should be noted that after calculating the primary ratio values ​​of various inks, the present application performed further spectral optimization based on the difference between the actual reflected light intensity and the theoretical synthetic light intensity of the target printed material (ink mixing causes changes in the spectral reflectance characteristics), and adjusted the primary ratio value of each ink by analyzing the difference, thereby avoiding printing color differences caused by changes in spectral reflectance characteristics due to ink mixing, thereby achieving correction of printing color differences of smart printing machines.

[0118] In addition, in another aspect of the present application, in some embodiments, the present application provides a large-scale intelligent printing machine, referring to Figure 4 , which is a schematic diagram of the structure of a large-scale intelligent printing machine according to some embodiments of the present application, and the large-scale intelligent printing machine 200 includes: a sensing system 201, a control system 202 and a printing end effector 203, which are described as follows:

[0119] The sensing system 201 in this application is mainly used to collect the reflected light intensity of different ink samples in each visible light band;

[0120] The control system 202 in the present application is mainly used to perform characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divide the printing color gamut formed by all ink samples into multiple printing color intervals based on the various optical characteristic values;

[0121] In addition, the control system 202 in the present application is also used to perform primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtain the primary matching ratio value of each ink;

[0122] In addition, the sensing system 201 in the present application is also used to automatically identify multiple characteristic bands of reflected light when the target printed object is printed, determine the reference energy distribution of the reflected light in each characteristic band, determine the diffusion ratio of the energy distribution after the ink is mixed according to all the reference energy distributions, and adaptively correct the primary ratio values ​​of various inks during printing through the diffusion ratio to obtain the secondary ratio values ​​of various inks;

[0123] The printing end effector 203, in the present application, is mainly used to control the ejection amount of each ink according to each secondary ratio value.

[0124] In addition, the present application also provides a computer device, which includes a memory and a processor, wherein the memory stores codes, and the processor is configured to obtain the codes and execute the above-mentioned printing correction method for a large-scale intelligent printing press.

[0125] In some embodiments, reference Figure 5 , which is an internal structure diagram of a computer device for implementing a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application. The printing correction method for an intelligent printing press in the above embodiment can be Figure 5 The computer device 300 shown in the figure is implemented, and the computer device 300 includes at least one processor 301, a communication bus 302, a memory 303 and at least one communication interface 304.

[0126] The processor 301 may be a general-purpose central processing unit (CPU), or an application-specific integrated circuit (ASIC) or one or more processors for controlling the execution of the printing correction method for the smart printer in the present application.

[0127] The communication bus 302 is used to transmit information between the above components.

[0128] The memory 303 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compressed optical disc, a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, etc.), a magnetic disk or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The memory 303 may exist independently and be connected to the processor 301 via the communication bus 302. The memory 303 may also be integrated with the processor 301.

[0129] The memory 303 is used to store the program code for executing the solution of the present application, and the execution is controlled by the processor 301. The processor 301 is used to execute the program code stored in the memory 303. The program code may include one or more software modules. The printing correction method for the intelligent printer in the above embodiment can be implemented by the processor 301 and one or more software modules in the program code in the memory 303.

[0130] The communication interface 304 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0131] In a specific implementation, as an embodiment, a computer device may include multiple processors, each of which may be a single-CPU processor or a multi-CPU processor. The processor here may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0132] The above-mentioned computer device may be a general-purpose computer device or a special-purpose computer device. In a specific implementation, the computer device may be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device or an embedded device. The embodiment of the present application does not limit the type of computer device.

[0133] In addition, the present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the printing correction method for the intelligent printer is implemented.

[0134] In summary, in the large-scale intelligent printing machine and the printing correction method for the large-scale intelligent printing machine disclosed in the embodiments of the present application, the reflected light intensity of different ink samples in each visible light band is collected by the sensing system; the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensity of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut composed of all ink samples into multiple printing color intervals based on the various optical characteristic values; the control system also performs characteristic conversion on various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval The first-level ratio of each ink is obtained by performing a first-level ratio matching according to the content of each ink; the sensing system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all the reference energy distributions, and adaptively corrects the first-level ratio values ​​of various inks during printing through the diffusion ratio to obtain the second-level ratio values ​​of various inks; the printing end effector controls the injection amount of each ink according to each second-level ratio value; and can adjust the optimal ink ratio of the target printed object when the spectral reflectance characteristics of the ink sample change.

[0135] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0136] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A printing correction method for a large-scale intelligent printing machine, wherein the large-scale intelligent printing machine includes a sensing system, a control system, and a printing end effector, characterized in that: The method comprises the following steps: The sensing system collects the reflected light intensity of different ink samples in each visible light band; The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the optical characteristic values; The control system also performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtains the primary matching ratio value of each ink; The sensing system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all the reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing according to the diffusion ratio to obtain the secondary ratio values ​​of various inks; The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

2. The method according to claim 1, characterized in that The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of reflected light intensities of each ink sample in all visible light bands, and obtains multiple optical characteristic values, specifically including: Determine the fluctuation characteristics of the reflected light intensity of various ink samples in all visible light bands; Determine the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample according to the fluctuation characteristics corresponding to the various ink samples; The fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical characteristic values ​​through the ratio of all light intensity fluctuations.

3. The method according to claim 1, characterized in that Based on each optical characteristic value, the printing color gamut formed by all ink samples is divided into multiple printing color intervals, including: Constructing color feature vectors of various ink samples based on the respective optical feature values; Determining vector proximity between color feature vectors of various ink samples; The printing color gamut formed by all ink samples is divided into multiple printing color intervals according to all vector approximations.

4. The method according to claim 1, characterized in that The control system performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtains the primary matching ratio value of each ink, specifically including: Determine the center spectral vector of each printed color interval; Obtaining a color spectrum vector of a target printed object; Determine the spectral similarity between the color of the target printed object and each printed color interval according to the central spectral vector of each printed color interval and the color spectral vector of the target printed object; Determine the optimal color range of the target print according to all spectral similarities; Setting an optimal matching function for all inks based on the optimal color interval; The optimal ratio function is used to determine the ratio of the contents of all inks during printing to obtain a primary ratio value of each ink.

5. The method according to claim 1, characterized in that Determining the reference energy distribution of reflected light in each characteristic band specifically includes: Obtain the reflected light intensity of each ink in each characteristic band; Determine the reflected composite light intensity of the target printed matter in each characteristic band according to the primary ratio value of each ink and the reflected light intensity of the ink in each characteristic band; The reference energy distribution of the reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band.

6. The method according to claim 1, characterized in that Determining the diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions specifically includes: Determine the energy distribution diffusion model through all reference energy distributions; The diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model.

7. The method according to claim 1, characterized in that The primary ratio values ​​of various inks are adaptively corrected by the diffusion ratio during printing to obtain the secondary ratio values ​​of various inks, which specifically include: Obtaining a shifted characteristic band of the ink sample after the spectral reflectance characteristic is shifted; Determine the compensation ratio value of each ink by using the diffusion ratio and the offset characteristic band; Based on the compensation ratio value corresponding to each ink, the primary ratio value of the corresponding ink is adaptively corrected, so as to obtain the secondary ratio values ​​of various inks.

8. A large intelligent printing machine, characterized in that: It includes a perception system, a control system, and a printing end effector. The sensing system collects the reflected light intensity of different ink samples in each visible light band; The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the optical characteristic values; The control system also performs primary matching of the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printing color interval, and obtains the primary matching ratio value of each ink; The sensing system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed according to all the reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing according to the diffusion ratio to obtain the secondary ratio values ​​of various inks; The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the printing correction method for a large-scale intelligent printing press according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the printing correction method for a large-scale intelligent printing press according to any one of claims 1 to 7 are implemented.

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