CN105300522A - Chromaticity quantitative calculation method capable of reducing influence of color measurement uncertainty - Google Patents

Abstract

The invention provides a chromaticity quantitative calculation method capable of reducing the influence of color measurement uncertainty. The method mainly comprises the following steps of 1: obtaining a standard specimen page; 2, preparing a computer and a spectrophotometer; 3, connecting and calibrating the spectrophotometer; 4, measuring and storing data; 5, analyzing, processing and exporting data; 6, quantitatively calculating the chromaticity of the visible light. According to the technical scheme of the invention, the invention provides a high-precision, high-efficiency and short-period chromaticity quantitative calculation method, and the characteristics of simple method, low cost, high precision and convenient actual production management are realized. The method can be applied to the fields of printing, dyeing, color copying and the like. By adopting the method, the influence of color measurement uncertainty on the chromaticity quantitative calculation is reduced.

Description

The uncertain sex colourity quantitative calculation method of a kind of reduction color measuring

Technical field

The invention belongs to the colorimetry field that visible ray colourity quantitatively calculates, be specifically related to the uncertain sex colourity quantitative calculation method of a kind of reduction color measuring.

Background technology

Color measuring uncertainty affects the key factor that color measuring and colourity quantitatively calculate accuracy, is to weigh the whether enough critical control point accurately of printing quality control data.Wavelength interval and wavelength coverage cause probabilistic two principal elements of color measuring, and whether the uncertainty of color measuring will directly affect color measuring result accurately and the levels of precision of chrominance distortion.Specify according to CIE15:2004, when making accurate colourity and quantitatively calculating, wavelength coverage should round the 360-780 of a visible spectrum, wavelength interval should be got 1nm and be calculated, but due to the restriction of the hardware products such as the monochromator in the beam splitting system of spectral photometric colour measuring instrument and the photodetector in receiving system, the degree of accuracy of the spectral reflectivity wavelength interval color measuring result causing spectral photometric colour measuring instrument to record is not ideal enough.Therefore, the spectral reflectivity corresponding to each wavelength measured by different surveying instruments carries out certain data analysis and process reduces the probabilistic key factor of color measuring, is also colorimetry field that visible ray colourity quantitatively calculates bottleneck problem urgently to be resolved hurrily.At present, the wavelength interval majority that spectral photometric colour measuring instrument uses when measuring is 10nm, minority adopts 5nm wavelength interval, can not meet the regulation that should use wavelength interval in CIE15:2004 to accurate Calculation tristimulus values, thus accurately can not calculate chromatic value.

Summary of the invention

The bottleneck problem existed during the visible ray colourity that the present invention is directed to current colorimetry quantitatively calculates, provides the uncertain sex chromatic value computing method of a kind of high-quality, efficient, accurate reduction color measuring.

The technical solution adopted for the present invention to solve the technical problems comprises the following steps:

Step 1: obtain standard specimen page

Select Ai Seli ColorCheckerClassic standard 24 look colour atla, obtain the CIE1976 homogeneous color space L that standard color card comprises color lump ^*a ^*b ^*d coordinates value L ^*a ^*b ^*and save as conventional spreadsheet format " .xls ",

Step 2. computing machine and spectral photometric colour measuring instrument prepare

Connect and start spectral photometric colour measuring instrument power supply, according to the requirement preheating certain hour of instrument operation instructions.Start-up simulation machine, and open the supporting spectral photometric colour measuring software of spectral photometric colour measuring instrument;

Step 3: spectral photometric colour measuring instrument connects and calibration

Connect spectral photometric colour measuring instrument and computing machine with data line, arrange apparatus measures condition and calibrate instrument, make surveying instrument reach standard operating conditions, concrete steps are as follows:

The 3-1. supporting data line of instrument connects spectral photometric colour measuring instrument and computing machine, guarantees to connect correctly between instrument and measurement instrument, and data transmission is stable and accurate.If cannot connect, need driver corresponding to spectral photometric colour measuring instrument is installed;

3-2. arranges apparatus measures condition as light source, field of view angle, wavelength output area, wavelength interval etc.;

3-3. utilizes the blank wiping tool of specialty to carry out wiping to the white point on blank, ensures the clean free from dust of white point, stain, cut;

The white point that measured hole is aimed on blank by 3-4. is calibrated surveying instrument according to spectral photometric colour measuring instrument or computer prompted, and spectral photometric colour measuring instrument or Computer display are calibrated successfully;

Step 4: DATA REASONING and preservation

The color region that aimed at the mark by measured hole makes the color block within the scope of whole measured hole without assorted point, and ensures to occur without bonding state with other color lumps, measures color according to the operation instructions of spectral photometric colour measuring instrument.Preservation measurement result after measurement completes, if the spreadsheet format of preserving data is not " .xls ", opens saving result and pastes in MicrosoftExcel by all data Replicas, data are saved as " .xls " form;

Step 5: Data Analysis Services and derivation

Business mathematics software Matlab in moving calculation machine after opening interpolation arithmetic program, import the data in " .xls " file, to this data analysis process, concrete steps are as follows;

Business mathematics software Matlab in 5-1. moving calculation machine, opens and runs interpolation arithmetic program;

5-2. is according to " .xls " file of gained in the prompting load step (4) of Matlab command window;

During 5-3. for circulates, nested interp1 () function reads and analyzing and processing every a line spectroscopic data, the spectral reflectance data obtained is carried out being saved to empty matrix;

Step 6: the quantitative calculating of visible ray colourity

6-1. utilizes for circulation to carry out mathematical computations to the every a line spectroscopic data preserved in step 5-3, utilizes nested formula 1 and formula 2 in circulation to calculate tristimulus values XYZ and CIE1976L ^*a ^*b ^*homogeneous color space D coordinates value L ^*a ^*b ^*

Formula 1: $V=k\underset{a}{\overset{b}{\Σ}}E\left(\mathrm{\λ}\right)v\left(\mathrm{\λ}\right)R\left(\mathrm{\λ}\right)\mathrm{\Δ}\mathrm{\λ}$

Wherein, Δ λ=5nm or 1nm

Formula 2: $\left\{\begin{array}{c}L=116F(Y/Y_n)-16\\ a^{*}=500\[F(X/X_n)-F(Y/Y_n)\]\\ b^{*}=200\[F(Y/Y_n)-F(Z/Z_n)\]\end{array}\right.$

6-2. utilizes formula 3 to calculate the L of each color lump that 4 kinds of data processing methods draw ^*a ^*b ^*value and standard L ^*a ^*b ^*aberration between value, and the mean value of trying to achieve each color lump aberration

Formula 3: ${{\mathrm{\ΔE}}_{ab}}^{*}=\sqrt{{\left({\mathrm{\ΔL}}^{*}\right)}^2+{\left({\mathrm{\Δa}}^{*}\right)}^2+{\left({\mathrm{\Δb}}^{*}\right)}^2}$

The aberration mean value that 6-3. is corresponding to 4 kinds of data processing methods in 6-2 compares, by minimum for aberration mean value one group of spectral reflectance data, tristimulus values XYZ and L ^*a ^*b ^*value saves as " .xls " file.

The color measurement instrument used in step 2 and step 3 must can be measured and export the spectral power distribution of color to be measured, and color measurement instrument must reach standard operating conditions by calibration, ensures the accuracy of acquisition data;

Data processor described in step 5 utilizes the interp1 () function in Matlab program software to work out, and completes the analyzing and processing of measurement data fast;

Tristimulus values described in step 6 calculates and makes the calculating of chromatic value lab more accurate.

Judge that whether disposal route is proper by data processed result analysis in step 6, and automatically can select data processed result method more accurately.

Beneficial effect of the present invention:

(1) the present invention is directed to the problem that the wavelength interval that exists in color measuring process is excessive, basic data can be obtained by measuring color block, on the basis ensureing measurement data correctness, automatically carrying out analyzing and processing to measurement result makes spectral reflectance data wavelength interval reduce one times, thus reduces the uncertainty of color measuring

(2) the present invention is by reducing the uncertainty of color measuring, and the computational accuracy that the data utilizing analyzing and processing to cross are carried out when colourity quantitatively calculates obtains corresponding raising.The colour reproduction such as printing, printing and dyeing neck can be promoted the use of, applicability and social value high.

Accompanying drawing explanation

Fig. 1 is the uncertain sex chromatic value calculation flow chart of a kind of reduction color measuring in the specific embodiment of the invention.

Fig. 2 reduces the uncertain sex method of color measuring in the specific embodiment of the invention

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described:

The uncertain sex colourity quantitative calculation method of the reduction color measuring that this method proposes, the treatment and analysis of specialty is carried out by the spectral reflectivity obtained actual measurement, solve the problem that the quantitative counting accuracy of colourity that current color measuring causes is low, the probabilistic degree of accuracy simultaneously making colourity quantitatively calculate reducing color measuring improves greatly, the significant and good using value of high-quality color subjective assessment in copying actual color.

As depicted in figs. 1 and 2, the uncertain sex colourity quantitative calculation method of a kind of reduction color measuring, comprises the following steps:

Step 1: obtain standard specimen page

Select Ai Seli ColorCheckerClassic standard 24 look colour atla, obtain the CIE1976 homogeneous color space L that standard color card comprises color lump ^*a ^*b ^*d coordinates value L ^*a ^*b ^*and saving as conventional spreadsheet format " .xls ", table content is as shown in the table.

Step 2. computing machine and spectral photometric colour measuring instrument prepare

Connect and start professional portable spectrophotometer ColorEyeXTH, according to the requirement preheating 30min of instrument operation instructions.Start-up simulation machine, and open the supporting software Coloricontrol of spectral photometric colour measuring instrument;

Step 3: spectral photometric colour measuring instrument connects and calibration

Connect spectral photometric colour measuring instrument and computing machine with data line, arrange apparatus measures condition and calibrate instrument, make surveying instrument reach standard operating conditions, concrete steps are as follows:

The 3-1. supporting data line of instrument connects spectral photometric colour measuring instrument and computing machine, guarantees to connect correctly between instrument and measurement instrument, and data transmission is stable and accurate.If cannot connect, need driver corresponding to spectral photometric colour measuring instrument is installed;

3-2. according to following optimum configurations apparatus measures condition, light source: D50, field of view angle: 2 °, wavelength output area 360nm-730nm, wavelength interval: 10nm;

3-3. utilizes the blank wiping tool of specialty to carry out wiping to the white point on blank, ensures the clean free from dust of white point, stain, cut;

The white point that measured hole is aimed on blank by 3-4. is calibrated surveying instrument according to the prompting of spectral photometric colour measuring instrument, and the display of spectral photometric colour measuring instrument is calibrated successfully;

Step 4: DATA REASONING and preservation

The color region that aimed at the mark by measured hole makes the color block within the scope of whole measured hole without assorted point, and ensures to occur without bonding state with other color lumps, measures color according to the operation instructions of spectral photometric colour measuring instrument.In Coloricontrol interface, choose the color lump completing measurement after having measured, copy and affix in the empty form of Excel and preserve measurement result for " primary data .xls "

Step 5: Data Analysis Services and derivation

Business mathematics software Matlab in moving calculation machine after opening interpolation arithmetic program, import the data in " primary data .xls " file, to this data analysis process, concrete steps are as follows;

Business mathematics software Matlab in 5-1. moving calculation machine, opens and runs interpolation arithmetic program;

5-2. is according to " primary data .xls " file of gained in the prompting load step (4) of Matlab command window;

5-3. interp1 (the 360:10:730 of for loop nesting, spectral reflectivity, 360:5:730, ' method ') function, wherein method is linear, nearest, cubic, spline, by four kinds of methods, every a line spectroscopic data is read and analyzing and processing respectively, obtain four groups of 24 × 76 spectral reflectance data are carried out being saved to empty matrix;

Step 6: the quantitative calculating of visible ray colourity

6-1. utilizes for circulation to carry out mathematical computations to the every a line spectroscopic data preserved in step 5-3, utilizes nested formula 1 and formula 2 in circulation to calculate tristimulus values XYZ and CIE1976L ^*a ^*b ^*homogeneous color space D coordinates value L ^*a ^*b ^*

Formula 1: $V=k\underset{a}{\overset{b}{\Σ}}E\left(\mathrm{\λ}\right)v\left(\mathrm{\λ}\right)R\left(\mathrm{\λ}\right)\mathrm{\Δ}\mathrm{\λ}$

Wherein, Δ λ=5nm or 1nm

Formula 2: $\left\{\begin{array}{c}L=116F(Y/Y_n)-16\\ a^{*}=500\[F(X/X_n)-F(Y/Y_n)\]\\ b^{*}=200\[F(Y/Y_n)-F(Z/Z_n)\]\end{array}\right.$

6-2. utilizes formula 3 to calculate the L of each color lump that 4 kinds of data processing methods draw ^*a ^*b ^*value and standard L ^*a ^*b ^*aberration between value, and the mean value of trying to achieve each color lump aberration

Formula 3: ${{\mathrm{\ΔE}}_{ab}}^{*}=\sqrt{{\left({\mathrm{\ΔL}}^{*}\right)}^2+{\left({\mathrm{\Δa}}^{*}\right)}^2+{\left({\mathrm{\Δb}}^{*}\right)}^2}$

The aberration mean value that 6-3. is corresponding to 4 kinds of data processing methods in 6-2 compares, by minimum for aberration mean value one group of spectral reflectance data, tristimulus values XYZ and L ^*a ^*b ^*value saves as " .xls " file.

The present invention carries out the treatment and analysis of specialty by the spectral reflectivity obtained actual measurement, solve the difficult problem that the quantitative counting accuracy of colourity that current color measuring causes is low, the probabilistic degree of accuracy simultaneously making colourity quantitatively calculate reducing color measuring improves greatly, the significant and good using value of high-quality color subjective assessment in copying actual color.

Claims (1)

1. reduce the uncertain sex chromatic value computing method of color measuring, it is characterized in that comprising the following steps:

Step 1: obtain standard specimen page

Select Ai Seli ColorCheckerClassic standard 24 look colour atla, obtain the CIE1976 homogeneous color space L that standard color card comprises color lump ^*a ^*b ^*d coordinates value L ^*a ^*b ^*and save as conventional spreadsheet format " .xls ",

Step 2. computing machine and spectral photometric colour measuring instrument prepare

Connect and start spectral photometric colour measuring instrument power supply, according to the requirement preheating certain hour of instrument operation instructions; Start-up simulation machine, and open the supporting spectral photometric colour measuring software of spectral photometric colour measuring instrument;

Step 3: spectral photometric colour measuring instrument connects and calibration

Connect spectral photometric colour measuring instrument and computing machine with data line, arrange apparatus measures condition and calibrate instrument, make surveying instrument reach standard operating conditions, concrete steps are as follows:

The 3-1. supporting data line of instrument connects spectral photometric colour measuring instrument and computing machine, guarantees to connect correctly between instrument and measurement instrument, and data transmission is stable and accurate; If cannot connect, need driver corresponding to spectral photometric colour measuring instrument is installed;

3-2. arranges apparatus measures condition, comprises light source, field of view angle, wavelength output area, wavelength interval;

3-3. utilizes the blank wiping tool of specialty to carry out wiping to the white point on blank, ensures the clean free from dust of white point, stain, cut;

The white point that measured hole is aimed on blank by 3-4. is calibrated surveying instrument according to spectral photometric colour measuring instrument or computer prompted, and spectral photometric colour measuring instrument or Computer display are calibrated successfully;

Step 4: DATA REASONING and preservation

The color region that aimed at the mark by measured hole makes the color block within the scope of whole measured hole without assorted point, and ensures to occur without bonding state with other color lumps, measures color according to the operation instructions of spectral photometric colour measuring instrument; Preservation measurement result after measurement completes, if the spreadsheet format of preserving data is not " .xls ", opens saving result and pastes in MicrosoftExcel by all data Replicas, data are saved as " .xls " form;

Step 5: Data Analysis Services and derivation

Business mathematics software Matlab in moving calculation machine after opening interpolation arithmetic program, import the data in " .xls " file, to this data analysis process, concrete steps are as follows;

Business mathematics software Matlab in 5-1. moving calculation machine, opens and runs interpolation arithmetic program;

5-2. is according to " .xls " file of gained in the prompting load step (4) of Matlab command window;

During 5-3. for circulates, nested interp1 () function reads and analyzing and processing every a line spectroscopic data, the spectral reflectance data obtained is carried out being saved to empty matrix;

Step 6: the quantitative calculating of visible ray colourity

6-1. utilizes for circulation to carry out mathematical computations to the every a line spectroscopic data preserved in step 5-3, utilizes nested formula 1 and formula 2 in circulation to calculate tristimulus values XYZ and CIE1976L ^*a ^*b ^*homogeneous color space D coordinates value L ^*a ^*b ^*

Formula 1: $V=k\underset{a}{\overset{b}{\Σ}}E\left(\mathrm{\λ}\right)v\left(\mathrm{\λ}\right)R\left(\mathrm{\λ}\right)\mathrm{\Δ}\mathrm{\λ}$

Wherein, Δ λ=5nm or 1nm

Formula 2: $\left\{\begin{array}{c}L=116F(Y/Y_n)-16\\ a^{*}=500\[F(X/X_n)-F(Y/Y_n)\]\\ b^{*}=200\[F(Y/Y_n)-F(Z/Z_n)\]\end{array}\right.$

6-2. utilizes formula 3 to calculate the L of each color lump that four kinds of data processing methods draw ^*a ^*b ^*value and standard L ^*a ^*b ^*aberration between value, and the mean value of trying to achieve each color lump aberration

Formula 3: ${{\mathrm{\ΔE}}_{ab}}^{*}=\sqrt{{\left({\mathrm{\ΔL}}^{*}\right)}^2+{\left({\mathrm{\Δa}}^{*}\right)}^2+{\left({\mathrm{\Δb}}^{*}\right)}^2}$

The aberration mean value that 6-3. is corresponding to four kinds of data processing methods in 6-2 compares, by minimum for aberration mean value one group of spectral reflectance data, tristimulus values XYZ and L ^*a ^*b ^*value saves as " .xls " file.