TWI512274B - Method and apparatus for color calibration of imaging colorimeter - Google Patents

Description

Correction method and measuring device for image color analyzer

The invention relates to the correction of an image color analyzer, in particular to a method and a measuring device for an image color analyzer.

In today's large-scale illuminating samples, such as monitors, mobile phone panels, LED strips, lighting fixtures, etc., if measured in a single point, the measurement time is bound to increase a lot, so the filter must be A face color analyzer to increase the measurement area to improve measurement efficiency. The principle of the filter color analyzer is mainly based on the transmittance curve of the three filters and the response curve of the surface detector to simulate the color scheme of the International Commission on Illumination (CIE). The three filters are switched separately during the measurement, so that the chromaticity value and the luminance value of each point in the two-dimensional field of view can be obtained under one measurement, and the non-filtered color analyzer is used for different samples. The calibration needs to be re-calibrated because the luminescence characteristics and spectral curves of different samples are different, such as CCFL, polycrystalline LED (RGB mixed light), single crystal LED (blue LED+YAG/TAG), etc. In view of this, an immediate correction architecture is required to improve measurement accuracy and convenience.

Please refer to US Patent No. 5,986,767 issued by Olympus Optical, which mainly proposes a filtering method for color analyzers, including Maximum Value Extraction, Fourier Transform Method, etc. These methods are combined with the numerical analysis method of the back end to achieve the purpose of measuring the chromaticity, but the content is more emphasis on the extraction of the spectral curve by the software method, and the numerical method is used to calculate the tristimulus values X, Y. And Z, and then obtain the chromaticity value and the luminance value of each point in the two-dimensional field of view.

Please refer to the patent US 7,012,633 issued by Radiant Imaging, which mainly proposes a color analysis correction method. First, an error correlation matrix (Error Correction Matrix) is calculated by measuring a single color light source with a known luminance value, and then The correction coefficients C _{x 1} , C _{x 2} , C _y , C _z of the four filters are calculated from the source and error correlation matrix of known chromaticity or spectrum, but the method must be known before the measurement. With chrominance, and the error correlation matrix and correction coefficient are recalculated for different color light sources, and the spectrum equation is used for correction, the spectrum of 380 nm to 780 nm band is still needed, and the instantaneous correction and freely selected band correction cannot be performed, so the use is There are still some inconveniences.

Looking at the above patents, the current filter color analyzer is still unable to achieve immediate correction, and for different samples, it needs to be recalibrated to measure.

Based on the above problems, the inventors have proposed a correction method and a measuring device for an image color analyzer to overcome the drawbacks of the prior art.

The invention provides an image color analyzer calibration method and a measurement device, which are based on a filter color analyzer, and in the process of measuring chromaticity and luminance, a single-point spectrometer Perform on-the-spot correction, compare the single-point spectral information with the two-dimensional filter image, and calculate the correction function of each point of the image, thereby improving the measurement accuracy and convenience of different samples, and conforming to large-area illumination On-line inspection requirements for samples.

To achieve the above statement, the present invention provides a method for correcting an image color analyzer, the method comprising: obtaining a correction function F(x, y) for each point (x, y) in space by a filter color analyzer Obtaining a chromaticity value C(x, y) and a luminance value L(x, y) at each point (x, y) in space by the filter color analyzer; obtaining at least one color single point by a spectrometer ( x _p, y _p) is a spectral data _{S (x p, y p)} ; receives the chrominance value of the filter type color analyzer of C (x, y) to a processor, the luminance value L (x, y) and the calibration function F(x, y), and the spectral data S(x _p , y _p ) of the single point (x _p , y _p ) of the spectrometer, and then compared by the processor Obtaining a first parameter K _C and a second parameter K _{L of} the single point (x _p , y _p ), wherein the first parameter K _C =S(x _p , y _p )/C(x _p , y _p And the second parameter K _L =S(x _p ,y _p )/L(x _p ,y _p ); calculating, by the processor, a global chromaticity correction function C′(x, y)=F(x, y) × K _C and a global luminance correction function L'(x, y) = F(x, y) × K _L ; and the processor obtains the corrected global chrominance value C" (x, y) =C(x,y)×C'(x,y) and the global luminance value L"(x,y)=L(x,y)×L'(x,y).

In order to achieve the above statement, the present invention provides a measuring device for an image color analyzer, comprising: a color analyzer having a lens group, at least one color filter and a two-dimensional array detector, the lens The group is spaced apart from the two-dimensional array detector and disposed adjacent to a sample, the two-dimensional array detector is disposed away from the sample, and the at least one color filter is disposed on the lens group and the two-dimensional array Between the detectors, the two-dimensional array detector passes through the at least one color filter and obtains an image range and an optical data on the sample through the lens group; a spectrum analyzer is adjacent to the color analyzer The spectrometer has a collecting lens and a spectrometer, the collecting lens is spaced apart from the spectrometer, and the collecting lens is disposed adjacent to the sample, the spectrometer is disposed away from the sample, and the spectrometer passes through the set The optical lens obtains a calibration point data in the image range; and a processor is electrically connected to the color analyzer and the spectrum analyzer, and receives the image range of the color analyzer and the School data and the spectrum analyzer correction point data, for comparison with the data processing.

While the invention has been described by way of a few embodiments, the invention

1 is a schematic structural view of a measuring device of an image color analyzer according to the present invention; the measuring device 1 of the image color analyzer of the present invention includes a color analyzer 2, a spectrum analyzer 3, and a processor. 4.

The color analyzer 2 has a lens group 21, at least one color filter 22, and a two-dimensional array detector 23, and the two-dimensional array detector 23 can be a charge coupled device (CCD). At least one color filter 22 is disposed between the lens group 21 and the two-dimensional array detector 23, and when the color filter 22 is plural, it can be a rotary structure; the two-dimensional array detector 23 Passing through at least one color filter 22 and passing through the lens group 21 to obtain an image range R and an optical data on the sample 5. The optical data includes at least a chromaticity value C (x, y) and a luminance value L (x, y). And the correction function F(x, y).

The spectrum analyzer 3 is disposed adjacent to the color analyzer 2, and the two can be a single system, but not limited thereto; the spectrum analyzer 3 has a collecting lens 31 and a spectrometer 32, and the spectrometer 32 is transmitted through the collecting lens. 31 A correction point data (correction point Q) is obtained in the image range R.

The processor 4 is electrically connected to the color analyzer 2 and the spectrum analyzer 3, and receives the image range R of the color analyzer 2 and its optical data, and the calibration point data of the spectrum analyzer 3 for data comparison and processing.

Please refer to FIG. 2, which is a schematic diagram showing the calibration method of the image color analyzer of the present invention applied to a single color single point calibration; the steps are as follows: Step S1I: obtaining each point on the image range R by the filter color analyzer 2 ( A correction function F(x, y) of x, y), if obtained, performs the following steps; Step S12: obtaining a chromaticity value of each point (x, y) in the image range R by the filter color analyzer 2 C (x, y) and the luminance value L (x, y); step S13: in the analyzer 3 made of at least a single color single point (x _p, y _p) is a spectral data _{S (x p, y p)} ; Step S14: The processor 4 receives the chromaticity value C(x, y), the luminance value L(x, y) of the filter color analyzer 2, and the correction function F(x, y), and the single spectrum analyzer 3 the point (x _p, y _p) spectral data _{S (x p, y p)} , then by the processor 4 to obtain a single point (x _p, y _p) of the first parameter a second K _C and a matching The second parameter K _L , wherein the first parameter K _C =S(x _p ,y _p )/C(x _p ,y _p ) and the second parameter K _L =S(x _p ,y _p )/L(x _p , y _p); step S15; 4 processor to calculate a global color correction function C '(x, y), and a global luminance correction Function L '(x, y), wherein color gamut correction function C' (x, y) = F (x, y) × K C, the luminance global correction function L '(x, y) = F (x, y ×K _L ; and step S16: the processor 4 obtains the global chrominance value C"(x, y) and the global luminance value L"(x, y) of the corrected image range R, wherein the global chrominance value C" ( x, y) = C (x, y) × C' (x, y), the global luminance value L" (x, y) = L (x, y) × L' (x, y).

Among them, the correction function F(x, y) is a value between 0 and 1.

The obtaining of the correction function in the above step S11 is optional, that is, the following comparison and calculation can be performed only once before each operation.

Please refer to FIG. 3 again, which is a schematic diagram showing the correction method of the image color analyzer of the present invention applied to three different color (R, G, B) corrections of a single point; the calibration method of the present invention can be applied as such, but Without limitation, the steps are as follows: Step S11: Obtain a correction function F(x, y) of each point (x, y) in the image range R by the filter color analyzer 2, and if so, perform the following Step S12: obtaining the chromaticity values C _{R, G, B} (x, y) and luminance values L _{R, G, B} of each point (x, y) in the image range R by the filter color analyzer 2 ( x, y); Step S21: obtaining a single point (x _p , y _p ) of respective spectral data S _R (x _p , y _p ), S _G (x _p , y _p ) by the spectrometer 3 And S _B (x _p , y _p ); Step S22: receiving, by the processor 4, the chromaticity values C _{R, G, B} (x, y), luminance values L _{R, G, B of the} filter color analyzer 2 (x, y) and the correction function F(x, y), and the spectral data S _R (x _p , y _p ), S _G (x _p , y ) of the single point (x _p , y _p ) of the spectrometer 3 _p) and _{S B (x p, y p} ), then by the processor 4 are aligned to obtain a single point (x _p, y _p) of each of the spectral data S _R (x _{p y p), S G (x} p, y p) and _{S B (x p, y p} ) of a first parameter and a second parameter K _C K _L, wherein the first parameter K _C = S _{R, G, B} (x _p , y _p )/C(x _p , y _p ) and a second parameter K _L =S _R,G,B (x _p ,y _p )/L(x _p ,y _p ); Step S23: Calculating, by the processor 4, a global chromaticity correction function C' _{R, G of} each spectral data S _R (x _p , y _p ), S _G (x _p , y _p ), and S _B (x _p , y _p ) _{, B} (x, y) and a global luminance correction function L' _{R, G, B} (x, y), where the global chromaticity correction function C' _{R, G, B} (x, y) = F (x, y) ×K _C , global luminance correction function L' _{R, G, B} (x, y) = F (x, y) × K _L ; and step S24: processor 4 obtains the global chrominance value C of the corrected image range R "(x,y) and global luminance value L"(x,y), where the global chromaticity value C" _R,G,B (x,y)=C _R,G,B (x,y)×C' _{R, G, B} (x, y) and global luminance value L" _{R, G, B} (x, y) = L _{R, G, B} (x, y) × L' _{R, G, B} (x, y ).

With the above-mentioned architecture and method, the immediate correction function can be achieved in the measurement process, thereby improving the measurement accuracy of the filter color analyzer for different samples. To sum up, firstly, the chromaticity and luminance information of the sample is obtained by the two-dimensional array detector and the color filter of the filter color analyzer, and the frequency of the calibration is determined by the spectrum obtained by the spectrometer, wherein if the sample is The single crystal LED is only corrected once (monochrome). The calibration is measured by a single-point spectrometer to obtain the spectrum information of the sample, and the filter-type global chromaticity, luminance data and spectroscopic single-point data are used. The comparison, the spectrum correction function of the whole domain is calculated, and the global chromaticity and luminance information is obtained by the two-dimensional correction function.

In the same way, if the sample is to be corrected by multi-color, for example, polycrystalline LED (RGB mixed white light), the sample is first switched to RGB three colors for correction, and RGB three-color spectrum information is obtained separately. The calibration is still measured by a single-point spectrometer, and is compared with the filter-wide global chromaticity and luminance data to obtain a three-color spectrum correction function, and then the color of each color after the image range R is calculated. Degree and brightness information.

Therefore, based on the filter color analyzer, the measurement is performed by a single-point spectrometer in the process of measuring chromaticity and luminance, and the single-point spectrum information is compared with the two-dimensional filter image information. Yes, the correction function of each point of the image and the true chromaticity and luminance information are calculated, thereby improving the measurement accuracy and convenience of different samples, and meeting the online detection requirements of large-area illuminating samples.

While the present invention has been explained in the above embodiments, it is not intended to limit the invention, and those skilled in the art can construct many other similar embodiments according to the inventive concept, which are all within the scope of the present invention. in.

1. . . Measuring device for image color analyzer

2. . . Color analyzer

twenty one. . . Lens group

twenty two. . . Color filter

twenty three. . . Two-dimensional array detector

3. . . Spectrum Analyzer

31. . . Collecting lens

32. . . spectrometer

4. . . processor

5. . . sample

Q. . . Calibration point

R. . . Image range

Steps S10 to S16 According to the steps of a calibration method of the present invention

Steps S21 to S24 According to another step of the calibration method of the present invention

1 is a schematic view showing the structure of a measuring device of an image color analyzer of the present invention.

Fig. 2 is a schematic view showing the correction method of the image color analyzer of the present invention applied to a single point single color correction.

Figure 3 is a schematic diagram showing the correction method of the image color analyzer of the present invention applied to a single point of three different color corrections.

1. . . Measuring device for image color analyzer

2. . . Color analyzer

twenty one. . . Lens group

twenty two. . . Color filter

twenty three. . . Two-dimensional array detector

3. . . Spectrum Analyzer

31. . . Collecting lens

32. . . spectrometer

4. . . processor

5. . . sample

Q. . . Calibration point

R. . . Image range

Claims (10)

An image color analyzer calibration method comprises: obtaining a chrominance value and a luminance value of each point in an image range by using a filter color analyzer; and obtaining a spectrum data of at least one calibration point by using a spectrum analyzer; Receiving, by a processor, the chromaticity value of the filter color analyzer, the luminance value and a correction function, and the spectrum data of the calibration point of the spectrum analyzer, and comparing by the processor to obtain a first parameter and a second parameter of the calibration point, wherein the first parameter is a ratio of the spectral data to the chrominance value, and the second parameter is a ratio of the spectral data to the luminance value; The processor calculates a global chrominance correction function and a global luminance correction function, wherein the global chrominance correction function is equal to the correction function and multiplied by the first parameter, the global luminance correction function is equal to the correction function and multiplied The second parameter; and the processor obtains a corrected global chrominance value and a global luminance value, wherein the global chrominance value is equal to the chromaticity value multiplied by the global chromaticity A direct function of the global luminance value based on the equal luminance value multiplied by the global luminance correction function. The method for correcting an image color analyzer according to claim 1, wherein before the step of obtaining a chrominance value and a luminance value at each point of an image range by a filter color analyzer, This correction function is obtained for each point in the image range with the filter color analyzer, and if it has been obtained, the subsequent steps are performed. According to the image color analyzer according to item 1 of the patent application scope A positive method in which the correction function is a value between 0 and 1. The method for correcting an image color analyzer according to claim 1, wherein the filter color analyzer and the spectrum analyzer are a single system. The method for correcting an image color analyzer according to claim 1, wherein the processor is electrically connected to the color analyzer and the spectrum analyzer. A measuring device for an image color analyzer, comprising: a color analyzer having a lens group, at least one color filter and a two-dimensional array detector, the lens group and the two-dimensional array detector The two-dimensional array detector is disposed away from the sample, and the at least one color filter is disposed between the lens group and the two-dimensional array detector. The two-dimensional array is disposed at a distance and adjacent to a sample. The detector passes through the at least one color filter and obtains an image range and an optical data on the sample through the lens group; a spectrum analyzer is disposed adjacent to the color analyzer, and the spectrum analyzer has a collecting lens And a spectrometer, the collecting lens is spaced apart from the spectrometer, and the collecting lens is disposed adjacent to the sample, the spectrometer is disposed away from the sample, and the spectrometer obtains a correction in the image range through the collecting lens. Point data; and a processor electrically connected to the color analyzer and the spectrum analyzer, and receiving the image range of the color analyzer and the optical data and the calibration point of the spectrum analyzer Materials, for comparison with the data processing. The measuring device of the image color analyzer according to claim 6, wherein the optical data includes at least a chromaticity value, a luminance value, and Correction function. The measuring device of the image color analyzer according to claim 6, wherein the correction point is a single point of three different colors. The measuring device of the image color analyzer according to claim 7, wherein the correction function is a value between 0 and 1. The measuring device of the image color analyzer according to claim 6, wherein the filter color analyzer and the spectrum analyzer are a single system.