Method for measuring the thickness or mass of a single color material at any point in a mixed color layered material

Abstract

The invention discloses a method for measuring the thickness or mass of a monochromatic material at any point of a mixed-color layered material, comprising the steps of: irradiating the monochromatic material with three uniform monochromatic light sources, obtaining the relationship between the astigmatism and the transmittance intensity of each monochromatic material before mixing from a transmission color image; obtaining a linear fitting equation of the actual thickness and astigmatism of the monochromatic material under the three monochromatic lights, constructing a binary or ternary linear mixed-color equation group based on the theory of constant total astigmatism, and; and, a step of: bringing the measured astigmatism of the mixed-color material into the mixed-color equation group, solving the cumulative thickness and mass ratio of each monochromatic material at any point, or calculating the relative thickness or mass ratio of each monochromatic material, without performing complex internal structure analysis or destructive testing, and using the algorithm of the invention to obtain a more accurate relative surface density or thickness of each monochromatic material in the mixed-color.

Description

[Technical field]

[0001] The present invention relates to the technical field of methods for the relative thickness and mass proportion of each monochromatic material in a mixed color material, and in particular to the technical field of methods for calculating the thickness and mass of a monochromatic material at any point in a layered strongly scattering or non-strongly scattering mixed color layered material. [Background technology]

[0002] The thickness or mass distribution of each monochromatic material in a mixed material is an important feature to characterize the structure and mass (or thickness) distribution uniformity of the mixed material. It is also an important basis for studying the thickness or mass proportion of each monochromatic material at any point in the mixed material.

[0003] Lambert's law based on unidirectional absorption is widely used in the thickness of translucent materials. It is the quantitative basis of absorptiometry, colorimetry and photoelectric colorimetry, and is also the theoretical condition for ultraviolet spectrophotometry to calculate the thickness of transparent media based on the degree of medium absorbance. However, this theory will produce large deviations when applied to strongly scattering materials and thicker materials. Therefore, the author and his team derived an algorithm for calculating the surface density of white layered fiber assemblies from transparent signals (patent number: CN105403482A), which overcomes the measurement deviation problem of Lambert's theory and makes it possible to calculate the whisker line density curve (patent number: CN106769652) and fiber length distribution.

[0004] In the visible and invisible light range, the same medium has different absorption capacity for light of different wavelengths, and different media also have different absorption capacity for the same monochromatic light. At present, researchers at home and abroad are committed to using color transmission images to study the internal structure and characteristics of materials: 1) Material quality: Using color transmission images illuminated by cold light, L value in Lab space and G value in RGB, Sobel operator and morphological method are used to extract three features, and a ternary freshness model is constructed by regression method to perform real-time freshness detection and grading of poultry eggs; the colorimetry of the reflection and transmission images of tobacco leaves is used to identify the intrinsic quality characterization of tobacco leaves. 2) Overcoming the inability to distinguish colors in blood leakage detection: Based on the change in light transmittance in the dialysate caused by blood leakage, the detected RGB signal is converted into an HSL signal, and brightness is used as the basis for judging blood leakage, and saturation and chromaticity signals are used as references to prevent misjudgment; 3) Plant lesions: Remote sensing technology is used to obtain the transmission image of corn disease spots, and the corn leaf spot disease is automatically classified and identified based on the difference between the image pixel values ​​and RGB values ​​of different spots. However, none of the above studies have been able to solve the problem of analyzing and calculating the relative thickness and mass proportion of each color material in the mixed color material.

[0005] In order to obtain the relative thickness and proportion of each color material at any point in a planar mixed color material, in 2018, my team and I proposed a test method for the cumulative thickness and mass proportion of each color material at any point in the mixed color material (patent number: CN107796315A). This patent uses RGB images, applies Lambert's law to the three-dimensional color space of red, green, and blue (R, G, B), establishes a calculation method based on the color transmittance image of the material, and designs a series of experiments to prove the applicability of the algorithm on common polymer materials, effectively solving the analytical calculation problem of the thickness and mass proportion of each monochromatic material in low-scattering mixed color materials. However, Lambert's law still has large deviations when applied to strongly scattering materials and thick fiber materials. In addition, when measuring strongly scattering materials, the above patent uses the optical parameter H in the algorithm for calculating the surface density of white layered fiber assemblies using transmittance signals derived by the author for color separation, that is, H w = bSX, where b, S and X are all parameters related to the optical properties of the material. However, due to the optical parameters H of the mixed color material and the single color material in the patent w The summation theory is incomplete, and both the mixed-color and single-color materials use the same infinite thickness reflectivity parameter. Therefore, this method can only preliminarily calculate the relative thickness or mass proportion of each single-color material in some mixed-color materials. [Summary of the invention]

[0006] The technical problem to be solved by the present invention is how to obtain an accurate calculation method for the cumulative relative thickness and mass proportion of each single color material at any point in a planar layered mixed color material, especially for mixed color materials containing strong scattering components and thicker materials.

[0007] To achieve the above object, the present invention provides a method for measuring the thickness or mass of a single-color material at any point of a mixed-color layered material, comprising the following steps:

[0008] Step 1: Obtain the relationship between the astigmatism and light transmittance of each monochromatic material before color mixing:

[0009] ① Test the transmittance intensity R, G and B of the i-th material (i=1, 2, 3) under red, green and blue monochromatic light respectively;

[0010] ② Calculate the astigmatism PiR, PiG and PiB of the i-th material under the illumination of red, green and blue monochromatic light respectively;

[0011]

[0012]

[0013]

[0014] In the formula, r ∞,R 、r∞,G and r ∞,B are the reflectance of the ith material when it is piled to infinite thickness under the illumination of red, green and blue monochromatic light, in %; R0, G0 and B0 are the total light intensity of red, green and blue monochromatic light, respectively;

[0015] Step 2: Construct a color mixing equation group of the relationship between the true thickness of each single color material in the color mixing material and the total astigmatism of the color mixing material:

[0016] ① Find the linear relationship range between the actual thickness x of the i-th material and the astigmatism, and use the linear fitting method to find the linear equation between the actual thickness x of the i-th material and the astigmatism, and use P i,m =S i,m X i +D i,m It represents the astigmatism of the i-th material under the m-th monochromatic light (m=R,G,B):

[0017] P 1，R =D 1，R +S 1，R x1,P 2，R =D 2，R +S 2R x2 (4);

[0018] P 1，G =D 1，G +S 1，G x1,P 2，G =D 2，G +S 2G x2 (5);

[0019] P 1，B =D 1，B +S 1，B x1,P 2，B =D 2，B +S 2，B x2 (6);

[0020] In the formula, x i is the actual thickness of the i-th material, in cm; S i，m and D i，m is the constant of the linear fitting equation, where S i，m Related to the astigmatism properties of the material itself and D i，m Related to noise.

[0021] ②P mix，m The astigmatism of the mixed material under the irradiation of the mth monochromatic light is expressed by the following method to construct the astigmatism of the mixed material and the astigmatism of each monochromatic material x i The relationship equation for thickness is:

[0022] A) When two materials are mixed:

[0023] P mix，m =P 1，m +P 2，m (7);

[0024] Among them, by substituting equations (4), (5) and (6) into equation (7), three equations can be obtained. After the simultaneous equations, a binary linear color mixing equation system can be constructed;

[0025] B) When the three materials are mixed:

[0026] P mix，m =P 1，m +P 2，m +P 3，m (8);

[0027] Substituting equations (4), (5) and (6) into equation (8), we can obtain three equations, and then after simultaneous equations, we can construct a three-variable linear color mixing equation system;

[0028] Step 3: Calculate the thickness and mass or relative thickness and mass of each single color material in the mixed color material:

[0029] According to formulas (1), (2) and (3), the total astigmatism of the material under each monochromatic light is calculated from the transmittance intensities R, G and B of the mixed color material, and the thickness and mass of each monochromatic material in the mixed color layered material are calculated by substituting the corresponding binary linear color mixing equation group or ternary linear color mixing equation group. If the linear color separation result is a constant multiple of the true value due to factors such as noise and random deviation, the blank group is used to eliminate the noise and perform normalization to calculate the relative thickness and relative mass of each monochromatic material in the mixed color layered material.

[0030] As a preference, the reflectivity r of an infinitely thick material under the illumination of red, green and blue monochromatic light is ∞ That is, the reflectivity of materials with a thickness of 0.5 to 3 cm.

[0031] Preferably, in step 1, uniform red, green and blue monochromatic light sources are used to illuminate the layered sample, and digital imaging technology is used to obtain a digital color image of the transmitted light of the layered sample.

[0032] Preferably, the layered sample is a layered fiber assembly sample or a layered sample formed by stacking polymer films or debris.

[0033] Beneficial effects of the present invention:

[0034] This patent proposes for the first time an algorithm for calculating the relative thickness or mass proportion of each color separation fiber material in a mixed color layered fiber assembly using the constant astigmatism (P=SX) theory and the transmittance signal. The astigmatism summation theory proposed by the algorithm is more complete, and the single color and mixed color materials use their own different infinite thickness reflectivity parameters. The color separation effect is better than the color separation algorithm based on the original Lambert-Beer optical absorbance H=KX (K is a parameter related to the optical properties of the material). Without performing complex internal structure analysis or destructive testing, the algorithm of the present invention can be used to obtain a more accurate relative surface density or thickness of each single color material in the mixed color, laying a foundation for the measurement of the structure, performance and uniformity detection of each single color material in a layered mixed color material stacked with fibers or thin objects, and can be applied to non-strong / strong scattering materials and thicker materials.

[0035] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0036] Figure 1 The relationship between the number of layers of 1# light blue PET monochrome material and the transmittance, absorbance and astigmatism under red, green and blue monochromatic light;

[0037] Figure 2 The relationship between the number of layers of 2# light yellow PET monochromatic material and light transmittance, absorbance and astigmatism under red, green and blue monochromatic light;

[0038] Figure 3 Comparison of the thickness of each single color film in the PET mixed color film (2# light yellow: 1# light blue = 1:2 mixed) calculated by the present invention with the original Lambert model;

[0039] Figure 4 Comparison of the thickness of each single color film in the PET mixed color film (1# light blue: 2# light yellow = 3:1 mixed) calculated by the present invention with the original Lambert model;

[0040] Figure 5 The relationship between the number of layers of 3# pink PET monochrome film material and light transmittance, absorbance and astigmatism under red, green and blue monochromatic light;

[0041] Figure 6 The relationship between the number of layers of 4# cyan PET monochrome film material and light transmittance, absorbance and astigmatism under red, green and blue monochromatic light;

[0042] Figure 7 The relationship between the number of layers of 5# white PET monochrome film material and light transmittance, absorbance and astigmatism under red, green and blue monochromatic light;

[0043] Figure 8The relative thickness of each single color film in the PET mixed color film (1# light blue: 1# light yellow = 1:1 mixed) calculated by the present invention is compared with the Lambertian model;

[0044] Fig. 9 The relative thickness of each single color film in the PET mixed color film (1# light blue: 2# light yellow = 1:2 mixed) calculated by the present invention is compared with the Lambert-Beer derived model;

[0045] Fig.10 The relative thickness of each single color film in the PET mixed color film (3# pink: 4# cyan = 1:1 mixed) calculated by the present invention is compared with the Lambert-Beer derived model;

[0046] Fig.11 The relative thickness of each single color film in the PET mixed color film (3# pink: 4# cyan: 5# white = 1:1:1 mixed) calculated by the present invention is compared with the Lambert-Beer derived model;

[0047] Fig.12 The relationship between the number of layers of 6# dark blue PP polyester film and the transmittance, astigmatism and absorbance under red, green and blue monochromatic light;

[0048] Fig.13 The relationship between the number of layers of 7# deep yellow PP polyester film and the transmittance, astigmatism and absorbance under red, green and blue monochromatic light;

[0049] Fig.14 The relative thickness of each single color film in the PP mixed color film (6# dark blue: 7# dark yellow = 1:1) calculated by the present invention is compared with the Lambert-Beer derived model;

[0050] Fig.15 The relative thickness of each single color film in the PP\PET mixed color film (7# dark yellow: 4# cyan=1:1) calculated by the present invention is compared with the Lambert-Beer derived model. [Specific implementation method]

[0051] Example 1: Color measurement and calculation of the thickness and proportion of each color material in a two-color PET mixed material:

[0052] First, a uniform and transparent PET film (material information is shown in Table 1 below) is used to verify the correctness of the present invention. Materials 1# light blue and 2# light yellow are stacked in different numbers of layers, and the light transmittance of the monochromatic film is tested under the irradiation of red, green and blue monochromatic lights. Then, according to formulas (1), (2), (3), A=log(G0 / G) and A=log(B0 / B), the experimental relationships between the WW model astigmatism and the Lamber-beer model absorbance and the cumulative number of layers or thickness are calculated respectively.

[0053] Table 1 Material information of PET color film

[0054]

[0055] exist Figure 1 and Figure 2 In the linear range of absorbance and astigmatism under green and blue monochromatic light channels, the first four points are linearly fitted to obtain the actual thickness x1 and x2 of material 1# light blue and 2# light yellow and the corresponding astigmatism (P 1,G , P 1,B , P 2,G , P 2,B ) and absorbance (A 1,G , A 1,B , A 2,G , A 2,B ), and the results are shown in Table 2 below.

[0056] Table 2 Linear fitting equations of the scattering and absorbance of materials 1# light blue and 2# light yellow and the thickness of each monochromatic material

[0057]

[0058] Then, based on formula (7) and the relationship that the mixed color absorbance is equal to the sum of the monochromatic absorbances, the relationship equations between the total mixed color scattering and the total absorbance and the actual thickness of the two monochromatic materials are constructed, see formula (9) and formula (10).

[0059] Astigmatism:

[0060] Absorbance:

[0061] The materials 1# light blue and 2# light yellow are stacked in the ratio of 2# light yellow: 1# light blue = 1:2 and 1# light blue 2#: light yellow = 3:1 to form mixed color materials with different numbers of layers. The corresponding light transmittance is measured respectively. The astigmatism P of each layer of the mixed color material is calculated by equation (2), equation (3), A = log (G0 / G) and A = log (B0 / B). mix,G , P mix,B and absorbance A mix,G , A mix,B The value of is substituted into equations (9) and (10) to calculate the thickness or mass of each single-color material. The results are shown in Figure 3 and Figure 4 .

[0062] Depend on Figure 3 and Figure 4It can be seen that the calculated thickness indirectly tested by the astigmatism color separation algorithm SX of this patent and the optical signal is also very close to the actual thickness. The deviation rate between the calculated result and the true value is 4.27% on average for the astigmatism model, 10.18% on maximum, and 6.58% on average for the Lambert-Beer model absorbance algorithm, with a maximum deviation rate of 20.40% (deviation rate = (actual value - calculated value) / actual value × 100%). In terms of thickness, this patented algorithm is significantly better than the original Lambert-Beer absorption algorithm, proving that this patented color mixing formula can be used to calculate the thickness of each color material at any light transmission point of the mixed color polyester PET material.

[0063] Example 2: Calculation of relative thickness and proportion of each color material in two-color and three-color PET mixed materials:

[0064] First, a uniform and transparent PET film (material information is shown in Table 3 below) is used to verify the correctness of the present invention. As in Example 1, materials 3# pink, 4# cyan and 5# white are stacked in different layers, and the light transmittance of the monochrome film under red, green and blue monochromatic light is tested, and then the experimental relationship between the WW model astigmatism P and the Lamber-beer model absorbance A and the cumulative thickness or number of layers under each channel is calculated.

[0065] Table 3 PET color film material information

[0066]

[0067] like Figure 5 , Figure 6 and Figure 7 As shown in the figure, the first three points of absorbance A and astigmatism P are linearly fitted to obtain the linear fitting equations of the actual thickness of the three PET materials and the corresponding astigmatism and absorbance under each monochromatic light. According to formula (8) and the mixed color absorbance being equal to the sum of the absorbances of each color separation, a mixed color ternary linear equation group is constructed.

[0068] Similar to Example 1, material 1# light blue material and material 2# light yellow material are stacked in a ratio of 1:1 and 1:2, material 3# pink and material 4# cyan are stacked in a ratio of 1:1, and material 3# pink, material 4# cyan and material 5# white are stacked in a ratio of 1:1:1 to form three groups of two-color mixed materials with different numbers of layers and one group of three-color mixed materials. The light transmittance corresponding to different thicknesses of these mixed materials is measured, and then the values ​​of the mixed color dispersion and absorbance of the mixed materials are calculated respectively using equations (2), (3), A=log(G0 / G) and A=log(B0 / B). After substituting the results into the right side of the corresponding mixed color binary linear and ternary linear equations, the relative thickness value of each monochromatic material is calculated and compared with the true value.

[0069] The results are as follows Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, the average deviation rate between the calculated results of the astigmatism model of the two-color mixed material and the true value is 2.32%, and the maximum deviation rate is 11.35%. The average deviation rate between the calculated results of the Lambert-Beer model absorbance algorithm and the true value is 5.08%, and the maximum deviation rate is 27.96%. The average difference rate between the calculated results of the astigmatism model of the three-color mixed material and the true value is 1.60%, and the maximum difference rate is 8.54%. The average difference rate between the calculated results of the Lambert-Beer model and the true value is 2.11%, and the maximum difference rate is 11.90%. More experiments are needed to verify the color separation effect of the three-color mixed material. The above results prove that the patent can be applied to the uniformity detection and relative thickness or mass distribution measurement of the two-color mixed material PET.

[0070] Example 3: Measurement of relative thickness or mass of each color material in a two-color PP mixed material:

[0071] First, a uniform and transparent PP film (material information is shown in Table 4 below) was used to verify the correctness of the present invention. As in Example 1, materials 6# dark blue and 7# dark yellow were stacked in different numbers of layers, and the light transmittance of the monochromatic film was tested under the irradiation of red, green and blue monochromatic lights, and the experimental relationship between the WW model astigmatism P, the Lamber-beer model absorbance A and the cumulative thickness or number of layers was calculated.

[0072] Table 4 PP color film material information

[0073]

[0074] like Fig.12 and Fig.13 As shown, the first three points in the figure are linearly fitted to obtain the linear fitting equations of the actual thickness of the two PP materials and the corresponding astigmatism and absorbance under green and blue monochromatic light, and a color mixing binary linear equation group is constructed.

[0075] According to the material 6# dark blue and 7# dark yellow in a ratio of 1:1, they are stacked in sequence to form mixed color materials with different numbers of layers. The corresponding light transmittance intensity is measured respectively, and the astigmatism and absorbance are calculated. After substituting the results into the corresponding set of two-variable linear equations, the relative thickness value of each single color is calculated.

[0076] Fig.14That is, the normalized relative thickness of the single-color film calculated based on the transmittance signal of the PP mixed-color frosted film is compared with the actual value. The average difference rate is 2.06%, and the maximum difference rate is 8.17%. The average difference rate of the Lambert-Beer model is 4.08%, and the maximum difference rate is 12.05%. The above results prove that the hybrid formula can be used to calculate the thickness or mass of each color material at any transmittance point of the mixed-color non-polyester PP material.

[0077] Example 4: Measurement of relative thickness of each color material in a two-color PP / PET mixed color material:

[0078] Similar to Example 1, using materials 4# cyan PET film and 7# dark yellow PP film, the regression linear equation and formula (7) under green and blue monochromatic light irradiation are used to construct a mixed color binary linear equation system of mixed color dispersion luminosity and absorbance.

[0079] The materials 7# dark yellow and 4# cyan were stacked in different layers in a ratio of 1:1. The total light divergence and total absorbance of the PP / PET films after stacking were measured under the irradiation of green and blue monochromatic light. The corresponding color mixing binary linear equations were substituted and normalized to obtain the relative thickness of each monochromatic film.

[0080] Fig.15 That is, the normalized relative thickness of the single-color film calculated based on the transmittance signal of the PP / PET mixed-color frosted film is compared with the actual value. The average difference rate is 3.11%, the maximum difference rate is 15.48%, and the average difference rate of the Lambert-Beer model is 24.73%, and the maximum difference rate is 164.74%. The above results prove that the hybrid formula can be used to calculate the relative thickness of each single-color material at any transmittance point of the mixed-color PP / PET material.

[0081] The present invention can solve the problem of the difficulty in analyzing and calculating the thickness and mass ratio of each color material when the mixed color material contains at least one strongly scattering material component. The algorithm is applicable to non-strongly scattering and strongly scattering materials, and has a wider scope of application than the color separation algorithm derived from the Lambert-Beer model. Without performing complex internal structure analysis or destructive testing, the algorithm of the present invention can obtain more accurate relative surface density or thickness of each monochromatic material in the mixed color, laying a foundation for the measurement of the structure, performance and uniformity detection of each monochromatic material in the layered mixed color material formed by fibers or thin objects.

[0082] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A method for measuring the thickness or mass of a single color material at any point of a mixed color layered material, characterized in that: The steps include: Step 1: Obtain the relationship between the astigmatism and light transmittance of each monochromatic material before color mixing: ① Test the transmittance intensity R, G and B of the i-th material under the illumination of red, green and blue monochromatic light respectively; ② Calculate the astigmatism P of the i-th material under the illumination of red, green and blue monochromatic light respectively iR , P iG and P iB ; In the formula, r ∞，R 、r ∞，G and r ∞，B are the reflectance of the ith material when it is piled to infinite thickness under the illumination of red, green and blue monochromatic light, in %; R0, G0 and B0 are the total light intensity of red, green and blue monochromatic light, respectively; Step 2: Construct a color mixing equation group of the relationship between the true thickness of each single color material in the color mixing material and the total astigmatism of the color mixing material: ① Find the linear relationship range between the actual thickness x of the i-th material and the astigmatism, and use the linear fitting method to find the linear equation between the actual thickness x of the i-th material and the astigmatism, and use P i，m =S i，m x i +D i，m It represents the astigmatism of the i-th material under the m-th monochromatic light: P 1，R =D 1，R +S 1，R x1,P 2，R =D 2，R +S 2，R x2 (4); P 1，G =D 1，G +S 1，G x1,P 2，G =D 2，G +S 2，G x2 (5); P 1，B =D 1，B +S 1，B x1,P 2，B =D 2，B +S 2，B x2 (6); In the formula, x i is the actual thickness of the i-th material, in cm; S i，m and D i，m is the constant of the linear fitting equation; ②P mix，m The astigmatism of the mixed material under the irradiation of the mth monochromatic light is expressed by the following method to construct the astigmatism of the mixed material and the astigmatism of each monochromatic material x i The relationship equation for thickness is: A) When two materials are mixed: P mix，m =P 1，m +P 2，m (7); Among them, by substituting equations (4), (5) and (6) into equation (7), three equations can be obtained. After the simultaneous equations, a binary linear color mixing equation system can be constructed; B) When the three materials are mixed: P mix，m =P 1，m +P 2，m +P 3，m (8); Substituting equations (4), (5) and (6) into equation (8), we can obtain three equations, and then after simultaneous equations, we can construct a three-variable linear color mixing equation system; Step 3: Calculate the thickness and mass or relative thickness and mass of each single color material in the mixed color material: According to formulas (1), (2) and (3), the total astigmatism of the material under each monochromatic light is calculated from the transmittance intensities R, G and B of the mixed color material, and the thickness and mass of each monochromatic material in the mixed color layered material are calculated by substituting the corresponding binary linear color mixing equation group or ternary linear color mixing equation group. When the linear color separation result is a constant multiple of the true value, the blank group is used to eliminate noise and normalize, and the relative thickness and relative mass of each monochromatic material in the mixed color layered material are calculated.

2. The method for measuring the thickness or mass of a single-color material at any point of a mixed-color layered material as claimed in claim 1, characterized in that: Under the illumination of red, green and blue monochromatic light, the reflectivity r of infinitely thick material is ∞ That is, the reflectivity of materials with a thickness of 0.5 to 3 cm.

3. The method for measuring the thickness or mass of a single-color material at any point of a mixed-color layered material as claimed in claim 1, characterized in that: In the step 1, uniform red, green and blue monochromatic light sources are used to illuminate the layered sample, and a digital color image of the transmitted light of the layered sample is obtained by using digital imaging technology.

4. The method for measuring the thickness or mass of a single-color material at any point of a mixed-color layered material as claimed in claim 3, characterized in that: The layered sample is a layered fiber assembly sample or a layered sample formed by stacking polymer films or debris.

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