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CN-122023545-A - Digital ink-jet printing color analysis method and system based on image processing

CN122023545ACN 122023545 ACN122023545 ACN 122023545ACN-122023545-A

Abstract

The invention discloses a digital ink-jet printing color analysis method and system based on image processing, and relates to the technical field of printing color analysis. According to the invention, the surface scattering distribution is constructed by acquiring a multi-angle fabric image, calculating brightness gradient and measured reflectivity and combining an initial absorption baseline, then the absorption baseline is iteratively updated by utilizing the reflectivity and the scattering distribution according to an energy conservation law, the absorption and scattering coefficients of the fabric are dynamically stripped, finally the dynamic coefficients are input into a Coebeck-Mang model as bottom parameters to reversely solve the target spectral reflectivity, and the optimal matching ratio is matched in an ink matching database, so that the high-precision color prediction of various complex fabrics without manual intervention is realized, the matching degree of printing colors and design intent is improved, and the problems that the color prediction adaptability is poor and automatic high-precision real color matching cannot be realized when facing the complex fabrics due to the fact that the correction coefficients and simple linear assumptions are set by relying on manual experience in the prior art are solved.

Inventors

  • Tan Pushun

Assignees

  • 绍兴柯桥赛邦纺织有限公司

Dates

Publication Date
20260512
Application Date
20260403

Claims (10)

  1. 1. The digital ink-jet printing color analysis method based on image processing is characterized by comprising the following steps of: acquiring a multi-angle fabric image and a printing template image under a standard light source; calculating pixel-level brightness gradient data of the surface of the fabric and measuring a reflectivity matrix based on the multi-angle fabric image; calculating a surface scattering distribution matrix of the fabric according to the pixel-level brightness gradient data and the initial absorption baseline matrix; According to the energy conservation logic, calculating and updating an initial absorption baseline matrix by using the measured reflectivity matrix and the surface scattering distribution matrix to obtain a texture correction absorption matrix; calculating a dynamic absorption coefficient and a dynamic scattering coefficient according to the surface scattering distribution matrix and the texture correction absorption matrix; the color data of the printing template image are combined with the dynamic absorption coefficient and the dynamic scattering coefficient to be input into a Coebeck Manger model, and target spectral reflectivity data is obtained through calculation; And searching the predicted spectral reflectivity matched with the target spectral reflectivity data in a preset ink proportioning database, and outputting a corresponding ink proportioning sequence.
  2. 2. The image processing-based digital inkjet printing color analysis method according to claim 1, wherein calculating a surface scattering distribution matrix of the fabric according to the pixel-level brightness gradient data and the initial absorption baseline matrix includes: Extracting an incident light intensity matrix of a standard light source; the specific formula for determining the surface scattering distribution matrix is as follows: ; Wherein, the Representing the surface scattering distribution matrix in coordinates The value at which the value is to be calculated, Representing pixel-level brightness gradient data at coordinates The value at which the value is to be calculated, Representing the incident light intensity matrix at coordinates The value at which the value is to be calculated, Representing the initial absorption baseline matrix at coordinates A value at.
  3. 3. The image processing-based digital inkjet printing color analysis method according to claim 1, wherein the calculating and updating the initial absorption baseline matrix to obtain the texture correction absorption matrix according to the energy conservation logic by using the measured reflectance matrix and the surface scattering distribution matrix comprises: establishing an energy conservation analytical equation of optical reflection of the opaque fabric; Based on an energy conservation analytic equation, a texture correction absorption matrix is obtained, and the specific formula is as follows: ; Wherein, the Representing the coordinates of the texture correction absorption matrix The value at which the value is to be calculated, Representing measured reflectance matrix at coordinates The value at which the value is to be calculated, Representing the surface scattering distribution matrix in coordinates A value at; setting the texture correction absorption matrix as a new initial absorption baseline matrix, and returning to execute the step of determining the surface scattering distribution matrix by adopting the following calculation logic until the absolute value of the difference value of the two calculation results of the texture correction absorption matrix is equal to the convergence threshold value.
  4. 4. The image processing-based digital inkjet printing color analysis method according to claim 1, wherein calculating the dynamic absorption coefficient and the dynamic scattering coefficient according to the surface scattering distribution matrix and the texture correction absorption matrix includes: reading a texture correction absorption matrix and a surface scattering distribution matrix which are output after the absolute value of the difference value is equal to the convergence threshold; extracting a pre-stored fabric material bulk density constant matrix; Calculating adamas Ma Chengji of the texture correction absorption matrix and the fabric material bulk density constant matrix to obtain a dynamic absorption coefficient; and calculating adamas Ma Chengji of the surface scattering distribution matrix and the fabric material volume density constant matrix to obtain a dynamic scattering coefficient.
  5. 5. The image processing-based digital inkjet printing color analysis method according to claim 1, wherein the step of inputting the color data of the printing template image into the kubelkam-shaped model by combining the dynamic absorption coefficient and the dynamic scattering coefficient, and calculating the target spectral reflectance data comprises the steps of: Analyzing the printing template image, and extracting a target color data matrix corresponding to the color channel; Converting the target color data matrix into a template reference reflectivity matrix by adopting a gray conversion algorithm; inputting the dynamic absorption coefficient and the dynamic scattering coefficient into a Coebeck model to calculate a coefficient ratio matrix; and carrying out inverse radiation solution based on the coefficient ratio matrix and the template reference reflectivity matrix to obtain target spectral reflectivity data.
  6. 6. The image processing-based digital inkjet printing color analysis method according to claim 5, wherein the coefficient ratio matrix is calculated by inputting the dynamic absorption coefficient and the dynamic scattering coefficient into a kubelkamank model, and the specific formula is: ; Wherein, the Representing dynamic absorption coefficient in coordinates The value at which the value is to be calculated, Representing dynamic scattering coefficients at coordinates The value at which the value is to be calculated, The ideal reflectivity of infinite thickness is expressed, and the ratio of the dynamic absorption coefficient and the dynamic scattering coefficient under the same coordinate forms a coefficient ratio matrix.
  7. 7. The image processing-based digital inkjet printing color analysis method according to claim 5, wherein the performing inverse radiation solution based on the coefficient ratio matrix and the template reference reflectivity matrix to obtain target spectral reflectivity data includes: taking the template reference reflectivity matrix as an initial value of ideal reflectivity with infinite thickness, and calculating a target ratio matrix; Establishing a residual function between the target ratio matrix and the coefficient ratio matrix; the calculation result of the residual function is equal to zero by adjusting the initial value; when the calculation result of the residual function is equal to zero, the initial value at this time is recorded as target spectral reflectance data.
  8. 8. The image processing-based digital inkjet printing color analysis method according to claim 1, wherein the searching the predicted spectral reflectance matching the target spectral reflectance data in the preset ink matching database, and outputting the corresponding ink matching sequence includes: traversing a preset ink proportion database to read theoretical spectrum parameters of a plurality of basic inks; According to a preset mixing rule, calculating theoretical spectral parameters of the combined basic ink to generate a predicted spectral reflectivity; and calculating the spectrum root mean square error of the target spectrum reflectivity data and the predicted spectrum reflectivity.
  9. 9. The image processing-based digital inkjet printing color analysis method according to claim 8, wherein after calculating the spectral root mean square error between the target spectral reflectance data and the predicted spectral reflectance, further comprising: recording the corresponding spectrum root mean square error under each group of mixed combination; extracting a corresponding mixed combination when the root mean square error of the spectrum is the minimum value; And converting the corresponding mixed combination when the spectrum root mean square error is the minimum value into an ink proportioning sequence in the form of an equipment control instruction, and outputting the ink proportioning sequence.
  10. 10. The digital ink-jet printing color analysis system based on image processing is used for realizing the digital ink-jet printing color analysis method based on image processing according to any one of claims 1-9, and is characterized by comprising an image acquisition module, a gradient reflection module, a scattering distribution module, an absorption updating module, a dynamic coefficient module, a target spectrum module and a proportion retrieval module; the image acquisition module is used for acquiring a multi-angle fabric image and a printing template image under a standard light source; The gradient reflection module is used for calculating pixel-level brightness gradient data of the surface of the fabric and measuring a reflectivity matrix based on the multi-angle fabric image; The scattering distribution module is used for calculating a surface scattering distribution matrix of the fabric according to the pixel-level brightness gradient data and the initial absorption baseline matrix; the absorption updating module is used for calculating and updating an initial absorption baseline matrix by utilizing the measured reflectivity matrix and the surface scattering distribution matrix according to the energy conservation logic to obtain a texture correction absorption matrix; The dynamic coefficient module is used for correcting the absorption matrix according to the surface scattering distribution matrix and the texture, and calculating a dynamic absorption coefficient and a dynamic scattering coefficient; The target spectrum module is used for inputting the color data of the printing template image into the Coebeck model by combining the dynamic absorption coefficient and the dynamic scattering coefficient, and obtaining target spectrum reflectivity data by means of calculation; the matching retrieval module is used for retrieving the predicted spectral reflectivity matched with the target spectral reflectivity data in a preset ink matching database and outputting a corresponding ink matching sequence.

Description

Digital ink-jet printing color analysis method and system based on image processing Technical Field The invention relates to the technical field of printing color analysis, in particular to a digital ink-jet printing color analysis method and system based on image processing. Background With the rapid development of digital printing technology, the precision requirement of the market on printing colors is increasingly improved. However, in practical production, there often occurs a problem that the color displayed by the digital screen has a significant deviation from the printing color of the final fabric, and especially for fabrics with complex optical characteristics such as silk, satin, cotton and hemp, the deviation is more significant. The prior art mainly relies on manual experience to set correction coefficients or adopts simple linear assumption to carry out color correction, for example, experience parameters such as diffuse reflection inhibition coefficients, specular reflection correction coefficients and the like are manually adjusted after a small amount of angle images are acquired. However, these methods are not only subjective and inefficient, but also difficult to cope with the huge difference of optical characteristics between different fabrics, resulting in poor adaptability of color prediction and low degree of automation, and cannot meet the requirements of efficient, accurate and consistent color matching in industrial production. Therefore, how to realize high-precision color prediction of various self-adaptive complex fabrics without relying on artificial experience becomes a technical problem to be solved in the field. Disclosure of Invention The embodiment of the application solves the problems that the color prediction adaptability is poor and automatic high-precision real color matching cannot be realized when facing complex fabrics due to the fact that correction coefficients and simple linear assumptions are set by relying on manual experience in the prior art by providing the digital ink-jet printing color analysis method and system based on image processing, realizes the accurate extraction of the optical characteristics of the fabrics through multi-angle imaging and physical iterative decoupling, and finally outputs the ink matching ratio matched with target colors by integrating the multi-angle imaging and physical iterative decoupling into a Coebeck-Mang model, thereby realizing the high-precision color prediction which does not need manual intervention and is suitable for various complex fabrics, and improving the matching degree of printing colors and design intentions. The embodiment of the application provides a digital ink-jet printing color analysis method based on image processing, which is applied to a digital ink-jet printing color analysis system based on image processing and comprises the following steps: acquiring a multi-angle fabric image and a printing template image under a standard light source; calculating pixel-level brightness gradient data of the surface of the fabric and measuring a reflectivity matrix based on the multi-angle fabric image; calculating a surface scattering distribution matrix of the fabric according to the pixel-level brightness gradient data and the initial absorption baseline matrix; According to the energy conservation logic, calculating and updating an initial absorption baseline matrix by using the measured reflectivity matrix and the surface scattering distribution matrix to obtain a texture correction absorption matrix; calculating a dynamic absorption coefficient and a dynamic scattering coefficient according to the surface scattering distribution matrix and the texture correction absorption matrix; the color data of the printing template image are combined with the dynamic absorption coefficient and the dynamic scattering coefficient to be input into a Coebeck Manger model, and target spectral reflectivity data is obtained through calculation; And searching the predicted spectral reflectivity matched with the target spectral reflectivity data in a preset ink proportioning database, and outputting a corresponding ink proportioning sequence. Further, the calculating the surface scattering distribution matrix of the fabric according to the pixel-level brightness gradient data and the initial absorption baseline matrix comprises the following steps: Extracting an incident light intensity matrix of a standard light source; the specific formula for determining the surface scattering distribution matrix is as follows: ; Wherein, the Representing the surface scattering distribution matrix in coordinatesThe value at which the value is to be calculated,Representing pixel-level brightness gradient data at coordinatesThe value at which the value is to be calculated,Representing the incident light intensity matrix at coordinatesThe value at which the value is to be calculated,Representing the initial absorption baseline matrix at coordi