KR20180012362A - System and method for measuring of luminance and chromaticity - Google Patents

Abstract

According to an embodiment of the present invention, a system for measuring luminance and chromaticity comprises: a chromaticity converting unit for converting first color data of a display panel for outputting a measurement image into first chromaticity data using a chromaticity conversion coefficient; a color space converting unit for converting the first color data into standard chromaticity data of a standard color space using a color space conversion matrix; and a standard color converting unit for converting the standard chromaticity data into standard color data using the sum of components of the standard chromaticity data. Also, according to an embodiment of the present invention, a method for measuring luminance and chromaticity comprises the steps of: extracting a chromaticity conversion coefficient and a color space conversion matrix, and photographing a display panel for outputting a measurement image to generate a first photographing image; extracting first color data from the first photographing image; converting the first color data into first chromaticity data using the chromaticity conversion coefficient, and converting first chromaticity data into standard chromaticity data of a standard color space using the color space conversion matrix; and converting the standard chromaticity data into standard color data the sum of components of the standard chromaticity data. Accordingly, first color data obtained by photographing a display panel once using a camera is converted into standard color data using previously extracted chromaticity conversion coefficient and color space conversion matrix, thereby promptly measuring luminance and chromaticity.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system and a method for measuring luminance and chromaticity,

The present invention relates to a system and method for measuring luminance and chromaticity.

In manufacturing a display device, chromaticity is measured from a display device through chromaticity measurement technology to evaluate the image quality, and the color realized in the display device is adjusted to improve the image quality of the display device.

This colorimetric technique uses a color matching function according to human color recognition for red, green, and blue and a human spectral response function according to recognition rate for each wavelength region of light, And the chromaticity of the image is calculated.

1 is a diagram showing a configuration of a conventional colorimetric apparatus 10.

The conventional chromaticity measuring apparatus 10 includes a condenser lens 11, a shutter 12, a filter wheel 13 on which color wheel function filters 13a, 13b and 13c are mounted, a CCD sensor 14 and a control module 15, .

The condenser lens 11 condenses and passes the light emitted from the measurement object area of the display device D and the shutter 12 is positioned between the condenser lens 11 and the CCD sensor 14 and is connected to the CCD sensor 14 To block or transmit light.

The filter wheel 13 has one or more color function filters 13a, 13b, 13c for passing only some light components in the light irradiated to the CCD sensor 14. [ At this time, the filter wheel 13 is rotated by the driving motor so that the color wheel function filters 13a, 13b, and 13c corresponding to the light components to be passed are positioned on the front surface of the CCD sensor 14. [

The color matching function filters 13a, 13b and 13c include an X-pole value filter 13a for passing an X-tristimulus value, a Y-pole value filter 13b for passing a Y-tristimulus value, And a Z-stimulus value filter 13c for passing a stimulus value (Z Tristimulus Value).

The CCD sensor 14 extracts the X-stimulus value passed through the X-stimulus value filter 13a by the pixel value of the color coordinate X and outputs the Y-stimulus value passed through the Y-stimulus value filter 13b to the Y- Pixel value, and extracts the Z-pole value passing through the Z-pole value filter 13c as the pixel value of the color coordinate Z. [

Then, the operation unit 15 converts the extracted pixel values of X, Y and Z into chromaticity chromaticity data (chromaticity coordinates) and outputs them.

That is, the conventional chromaticity measuring apparatus 10 rotates the filter wheel 13 provided with one or more color wheel function filters 13a, 13b, and 13c to sequentially pass only specific components of light to measure chromaticity data.

Accordingly, since the conventional chromaticity measuring apparatus 10 can measure the luminance and chromaticity by sequentially changing all the coloring function filters 13a, 13b, and 13c, it takes a long time to measure the luminance and chromaticity have.

In addition, the conventional chromaticity measuring apparatus 10 must have all of the color function filters that pass any one of the light components (X, Y, and Z) of the chromaticity data. Depending on the light components to be passed Since the filter changing means for rotating the coloring function filters 13a, 13b and 13c must be additionally provided, the volume of the apparatus becomes large and the manufacturing cost increases.

The conventional chromaticity measuring apparatus 10 measures luminance and chromaticity of a part of the entire display area of the display device D as a reference area to measure luminance and chromaticity of the center area as a reference area, There is a problem in that the measurement accuracy of the sensor is low.

The present invention is characterized in that second color data and measurement color data are obtained from a display panel that outputs a pattern image using a camera and a point instrument, respectively, and the obtained second color data and measurement color data are used to acquire an image The color conversion coefficient and the color space conversion matrix capable of converting the first color data of the first color data in the order of the first color data, the standard chroma data, and the standard color data are extracted to use an expensive face measuring instrument or a point measuring instrument It is another object of the present invention to provide a luminance and chrominance measurement system and method capable of quickly and accurately measuring luminance and chrominance of an image output from a display panel by photographing a display panel to measure luminance and chrominance without using a camera .

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description and more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

The conventional chromaticity measuring apparatus has a problem in that it takes a long time to measure the chromaticity by changing all the coloring function filters in order and requires a change unit of all coloring function filters and coloring function filters so that the manufacturing cost and the volume of the apparatus are increased .

In addition, since the conventional chromaticity measuring apparatus measures brightness and chromaticity of a reference area of a part of a display device, there is a problem in that the measurement accuracy in the reference area and the separated area is reduced.

In order to solve such a problem, in the luminance and chrominance measurement system according to an embodiment of the present invention, the first color data extracted from the first captured image of the display panel that outputs the measurement image is converted into the first chromaticity A color space conversion unit for converting the first color data into the standard chromaticity data of the standard color space by using the color space conversion matrix, and a chromaticity conversion unit for converting the standard chromaticity data into the standard chromaticity data by using the standard sum of the standard chromaticity data, And a standard color conversion unit for converting the data into data.

In addition, the luminance and chrominance measurement method according to an embodiment of the present invention extracts chromaticity conversion coefficients and a color space conversion matrix, and captures a display panel that outputs a measurement image to generate a first captured image. Then, the first color data is extracted from the first captured image. Then, the first color data is converted into the first chroma data using the chroma conversion coefficient, and the first chroma data is converted into the standard chroma data using the color space conversion matrix. Finally, the standard chromaticity data is converted into the standard color data using the component sum of the standard chromaticity data.

As described above, in the present invention, the first color data of the first captured image obtained by capturing the display panel one time by the camera after extracting the chroma conversion coefficient and the color space conversion matrix is referred to as first chroma data, standard chroma data, Thereby quickly and accurately measuring the luminance and chrominance of the image output from the display panel.

However, as described above, since the conventional chromaticity measuring apparatus is equipped with all the color acceptance function filters and the chromaticity is measured through the process of sequentially changing the chromaticity, the volume of the apparatus is increased and the measuring time takes a long time. Brightness and chromaticity are measured by converting the first color data of the photographed image photographed by the camera into standard color data using chromaticity conversion coefficients and a color space conversion filter.

According to the present invention, it is possible to speed up the luminance and chrominance of an image output from the display panel only by taking a picture of the display panel, and to measure the luminance and chromaticity accurately in the center region of the display panel as well as in the outer region of the display panel have.

According to the present invention as described above, chromaticity conversion coefficients and color space conversion matrices capable of converting first color data of a photographed image obtained by photographing a display panel with a camera into standard color data are extracted in advance, It is possible to quickly measure the luminance and chromaticity by converting the first color data acquired by photographing the display panel once with the camera to the standard color data.

Further, by converting the first color data by using the chroma conversion coefficient for approximating the color data of the photographed image photographed by the camera on the display panel with the measured color data measured by the point meter, It is possible to reduce the measurement error of the luminance and chromaticity occurring in the outer area of the panel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a configuration of a conventional colorimeter. FIG.
2 is a view showing a luminance and chromaticity measuring system according to an embodiment of the present invention and a point meter for measuring luminance and chromaticity of a display panel (D).
3 is a view illustrating a system for measuring luminance and chrominance and a camera for photographing a display panel according to an embodiment of the present invention.
4 is a view schematically showing a configuration of a luminance and chromaticity measurement system according to an embodiment of the present invention.
5 is a diagram illustrating a luminance and chrominance measurement system according to an embodiment of the present invention and a point meter for measuring measurement color data from a display panel for outputting a pattern image.
6 is a diagram illustrating a system for measuring luminance and chrominance according to an embodiment of the present invention and a camera for photographing a display panel for outputting a pattern image.
7 shows a data flow between a configuration of a luminance and chromaticity measurement system performing a calibration step;
8 is a view illustrating a system for measuring luminance and chrominance according to an embodiment of the present invention and a camera for photographing a display panel for outputting measurement images.
9 shows a data flow between the configurations of a luminance and chromaticity measuring system for performing a conversion step;
10 is a flowchart illustrating a process of performing a calibration step of a luminance and chrominance measurement method according to an embodiment of the present invention.
11 is a flowchart illustrating a process of performing a conversion step of a luminance and chrominance measurement method according to an embodiment of the present invention.

The above and other objects, features, and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, which are not intended to limit the scope of the present invention. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar elements.

FIG. 2 is a view showing a point meter 200 measuring the luminance and chromaticity of the luminance and chromaticity measuring system 100 and the display panel D according to an embodiment of the present invention. FIG. A camera 300 for photographing the luminance and chromaticity measuring system 100 and the display panel D according to the embodiment.

Referring to FIGS. 2 and 3, the point meter 200 can measure measured color data in a measurement area P on the display panel D. FIG.

More specifically, the point measuring instrument 200 can measure the measured color data by calculating the average of the measured color data in the measurement area P by contacting the surface of the light receiving part and the measurement area P.

Here, the measured color data may be a color coordinate in the CIE XYZ color space. The CIE XYZ color space is a color space established by the Commission Internationale de l'Clairage (CIE), which is a color space created based on data obtained by directly measuring human color perception to be. Accordingly, the CIE XYZ color space is a color space including all the color senses experienced by humans, and thus is a color space that becomes a standard for defining another color space.

Accordingly, the point measuring instrument 200 measures the measured color data on the basis of the CIE XYZ color space which is the standard color space.

On the other hand, when the luminance and chromaticity are to be measured for the entire area of the display panel D, ideally, the point meter 200 capable of accurately measuring the luminance and chromaticity with the color data on the CIE XYZ color space is used It is preferable to measure the entire area of the panel D. However, as long as a plurality of point meters 200 are provided for each of the plurality of measurement areas 1, ..., P, a plurality of point meters 200 are used, In the case of measuring all of the measurement areas 1, ..., P, it takes a long time to measure the luminance and chromaticity for the entire area of the display panel D.

Accordingly, the luminance and chrominance measurement system 100 according to an exemplary embodiment of the present invention can acquire color data of a photographed image obtained by photographing a display panel D with a camera 300 in a calibration step, using standard color data on a CIE XYZ color space And converts the color data of the photographed image into the standard color data in the CIE XYZ color space in the conversion step.

Here, the color data of the photographed image may be a color coordinate in the RGB color space. As for the RGB color space, the RGB color space is a color space in which colors are defined as combinations of red, green, and blue. The color space is used to detect and describe colors in an electronic device such as a display device, an image sensor (CCD, CMOS) , And the same color can have color data of different color coordinates depending on the electronic device.

That is, the luminance and chromaticity measuring system 100 can extract the chromaticity conversion coefficients and the color space conversion matrix using the measurement color data and the color data of the photographed image in the calibration step. Thereafter, the luminance and chromaticity measurement system 100 uses the chromaticity conversion coefficients and the color space conversion matrix to convert the color data of the photographed image of the display panel D, which outputs the measurement image for measuring the luminance and chromaticity, It can be converted into standard color data in the CIE XYZ color space.

Accordingly, the luminance and chromaticity measuring system 100 can measure the luminance and chromaticity of the display panel D by photographing the display panel D once.

Hereinafter, the luminance and chromaticity measurement system 100 will specifically describe a calibration step of extracting chromaticity conversion coefficients and a color space conversion matrix, and a conversion step of converting color data of the shot image into standard color data.

FIG. 4 is a view schematically showing a configuration of a luminance and chromaticity measuring system 100 according to an embodiment of the present invention. 4, a luminance and chromaticity measuring system 100 according to an exemplary embodiment of the present invention includes a panel driving unit 110, a meter driving unit 120, a camera driving unit 130, a coefficient extracting unit 140, A matrix extraction unit 160, a color space conversion unit 170, a standard color conversion unit 180, an output unit 190, and a storage unit DB.

First, the role of each component of the luminance and chromaticity measurement system 100 and the process of extracting chromaticity conversion coefficients and color space conversion matrices in the calibration step will be described.

5 is a view showing a point measuring instrument 200 for measuring measured color data from a luminance and chromaticity measuring system 100 according to an embodiment of the present invention and a display panel D for outputting a pattern image.

Referring to FIG. 5, the panel driver 110 may control the display panel D so that the pattern image is output to the display panel D in the calibration step. Here, the pattern image may be an image including a plurality of patterns (1, ..., N, where N is a natural number) in which brightness and chromaticity differ by a predetermined unit. That is, the panel driving unit 110 can control the display panel D so that the plurality of patterns 1, ..., N are output one by one to the display panel D.

The meter driving unit 120 is configured to measure the at least one measurement area 1, ..., P of the display panel D from which the point meter 200 outputs the plurality of patterns 1, ..., It is possible to drive the point measuring instrument 200 to measure the measurement color data.

As described above, the measurement color data measured by driving the point measuring device 200 by the meter driving unit 120 may be the color coordinates (X _{N, P} Y _{N, P} , Z _{N, P} ) in the CIE XYZ color space .

For example, when the point meter 200 measures the five measured color data in nine measurement areas on the display panel D, nine measured color data are measured for each pattern and a total of 45 measured color data are measured .

At this time, the measured color data measured in the fifth measurement area of the first pattern may be the color coordinates "X _1,5 , Y _1,5 , Z _1,5 " in the CIE XYZ color space.

At this time, the measurement color data can be expressed by a matrix as follows.

&Quot; (1) "

Here, X _{N, P} is an X triplet value in the Pth measurement region of the Nth pattern, Y is the triplet value in the Pth measurement region of the _{N, P} , Nth patterns, and Z _N, It is the Z triplet value in the P-th measurement area.

The meter driving unit 120 matches the measurement color data measured as a result of the operation of the point meter 200 with the position information of the measurement areas 1, ..., P on the display panel D, .

Next, the process of acquiring the second color data from the second captured image of the display panel D for outputting the pattern image will be described.

FIG. 6 is a diagram illustrating a camera 300 for photographing a luminance and chromaticity measuring system 100 according to an embodiment of the present invention and a display panel D for outputting a pattern image.

6, the camera driver 130 may drive the camera 300 to capture a display panel D that outputs a plurality of patterns 1, ..., N, have. More specifically, the camera driving unit 130 can drive the camera 300 so that the camera 300 captures the display panel D for each of a plurality of patterns 1, ..., N. [

Here, the camera 300 may be a color camera 300 that acquires a shot image using an image pickup device (CCD, CMOS). Also, the photographed image generated from the cameraphone 300 may be a digital image having color data for each pixel.

On the other hand, the camera driving unit 130 sets the exposure time (shutter speed), the aperture value, the ISO value, and the like of the camera 300 in order to photograph the display panel D under the same shooting conditions for each of the plurality of patterns 1, , The information can be set to be the same for every photographing of the plurality of patterns (1, ..., N).

The photographing distance L between the camera 300 and the display panel D and the photographing height H of the camera 300 can be fixed equally for each photographing of the plurality of patterns 1, have.

The camera driving unit 130 can extract the second color data from the second captured image of the display panel D that outputs the plurality of patterns 1, ..., N. More specifically, the camera driving unit 130 can extract second color data of pixel positions corresponding to the positional information of the measurement areas 1, ..., P on the display panel D from the second captured image .

For example, when the point measuring instrument 200 measures the five measured color data in nine measurement regions on the display panel D, the camera driving section 130 calculates the measurement color data from the second captured image obtained by capturing five patterns It is possible to extract the second color data at the pixel position corresponding to the position information of each of the nine regions.

Accordingly, the meter driving unit 120 obtains the nine measured color data for every five patterns to obtain a total of 45 measured color data, and the camera driving unit 130 also acquires nine second color data for each second captured image of five patterns It is possible to extract 45 pieces of second color data by extracting the color data.

Here, the second color data may be the color coordinates (RN _{, P} , _{GN, P} , _{BN, P} ) in the RGB color space and may be extracted at pixel positions corresponding to the fifth measurement region The second color data may be the color coordinates "R _1,5 , G _1,5 , B _1,5 " in the RGB color space.

In this case, the second color data can be expressed by the following equation (2).

&Quot; (2) "

Here, R _{N, P} is the red value of the pixel position corresponding to the Pth measurement region of the Nth pattern, G _{N, P} is the green value of the pixel position corresponding to the P th measurement region of the Nth pattern, and B _{N , And P} is the blue value of the pixel position corresponding to the Pth measurement region of the Nth pattern.

Meanwhile, the camera driving unit 130 may map the extracted second color data to the pixel position where the second color data is extracted, and store the mapped second color data in the storage unit DB.

In this second color data, color data different from the actual color data is obtained due to the viewing angle of the camera 300, the viewing angle of the display panel D, and the vignetting phenomenon. For example, in the case of outputting the image of the same chromaticity and luminance in the entire area of the display panel D and acquiring the second color data, the second color data extracted from the photographed image in the central area of the display panel D, The second color data extracted from the photographed image of the edge region of the panel (D) may have different chromaticity and luminance.

Hereinafter, the above-described data will be described with respect to the process of converting data by offsetting the data difference caused by the viewing angle of the camera 300, the viewing angle of the display panel D, and the vignetting phenomenon.

7 is a diagram illustrating data flow between the configurations of the luminance and chromaticity measurement system 100 performing the calibration step.

Referring to FIG. 7, the coefficient extracting unit 140 may extract the chromaticity transformation coefficient for approximating the second color data to the measured color data to offset the data difference of the second color data.

More specifically, the coefficient extracting unit 140 extracts the second color data from the viewing angle of the camera 300, the viewing angle of the display panel D, and the chromaticity conversion coefficient for approximating the second color data to the measurement color data in which there is no deviation due to the vignetting phenomenon Can be extracted for each of the measurement areas (1, ..., P) of the plurality of patterns (1, ..., N).

That is, the coefficient extracting unit 140 can extract chromaticity conversion coefficients that can cancel the deviation of the second color data due to the viewing angle of the camera 300, the viewing angle of the display panel D, and the vignetting phenomenon.

Then, the coefficient extraction unit 140 stores the extracted chroma conversion coefficients in the storage unit DB.

The coefficient extracting unit 140 may extract chromaticity transformation coefficients using the following Equation (3).

&Quot; (3) "

Here, (a _P , b _P , c _P ) is the chromaticity conversion coefficient in the P-th measurement region.

The chroma conversion unit 150 can convert the second color data into the second chroma data using the chroma conversion coefficient and convert the measured chroma data into the measured chroma data using the sum of the measured chroma data.

First, to describe the chromaticity data conversion of the chromaticity transforming unit 150, the chromaticity can be divided into two parts: chromaticity and luminance. In the CIE XYZ color space, the Y triplet value is a measure of the luminance of the color, and when the XYZ triplet is normalized, the color data can be converted into the chromaticity data excluding the luminance component.

Accordingly, the chromaticity transforming unit 150 can convert the measured color data into the measured chromaticity data by using the following expression (4).

&Quot; (4) "

Here, (x _{N, P} , y _{N, P} , z _{N, P} ) is the measured chromaticity data in the Pth measurement region of the Nth pattern and T ₁ is the component sum of the measured color data.

On the other hand, the chroma converting unit 150 can convert the second color data into the second chroma data using the chroma conversion coefficient. More specifically, the chroma converting unit 150 converts the second color data into the second chroma data using the chroma conversion coefficient extracted for each measurement region (1, ..., P) and the component sum of the second color data Can be converted.

At this time, the chroma converting unit 150 may convert the second color data into the second chroma data using the following equation (5).

Equation (5)

Here, (r _{N, P} , g _{N, P} , b _{N, P} ) is the second chroma data corresponding to the P th measurement region of the Nth pattern and T ₂ is the component sum of the second chroma data.

Accordingly, the chroma converting unit 150 can normalize the second color data and the measured color data, respectively, and convert the second chroma data and the measured chroma data into only the second chroma data and the measured chroma data.

The second chromaticity data is the rgb color space, and the color space of the measurement chromaticity data is the xyz color space.

When the color data of the RGB color space extracted from the photographed image photographed by the camera 300 is finally converted into the standard color data of the CIE XYZ color space, the chromaticity coordinates of the RGB color space are converted into the chromaticity coordinates of the rgb color space, The chromaticity coordinates of the rgb color space are converted into the chromaticity coordinates of the CIE xyz color space, and finally the chromaticity coordinates of the CIE xyz color space are converted into the CIE XYZ chromaticity coordinates.

The process of converting the chromaticity coordinates of the rgb color space to the chromaticity coordinates of the CIE xyz color space in the conversion process described above is performed using the color space conversion matrix for color space conversion into the CIE xyz color space in the rgb color space.

The matrix extraction unit 160 extracts the color space transformation matrix and specifically extracts a color space transformation matrix for approximating the second chroma data to the measurement chromaticity data.

At this time, the matrix extracting unit 160 may extract the color space transformation matrix using Equation (6).

&Quot; (6) "

Here, M is a color space transformation matrix, and m _1,1 to m _3,3 are elements of a color space transformation matrix.

Accordingly, the matrix extraction unit 160 can extract a color space transformation matrix capable of converting the chromaticity coordinates of the rgb color space into the chromaticity coordinates of the CIE xyz color space, which is a standard color space.

The matrix extraction unit 160 according to another embodiment extracts the color space transformation matrix for each of the same measurement regions without extracting the color space transformation matrix for approximating all the second chroma data to the measurement chromaticity data differently from the embodiment can do.

For example, the matrix extracting unit 160 according to another embodiment may calculate the second chroma data r (n) corresponding to the first measurement region of all the patterns 1, ..., N_{N, 1}, g_{N, 1}, b_{N, 1}) Of all the patterns (1, ..., N) The measurement chromaticity data corresponding to the first measurement area r_{N, 1}, g_{N, 1}, b_{N, 1}) Can be extracted from the color space conversion matrix for each measurement area.

At this time, the matrix extracting unit 160 according to another embodiment can extract the color space transformation matrix for each measurement region using Equation (7).

&Quot; (7) "

Here, M _P is a color space transformation matrix per measurement region, and m _1,1 'to m _3,3 ' are elements of a color space transformation matrix per measurement region.

Thereafter, the matrix extracting unit 160 according to another embodiment can interpolate the color space transformation matrix for each measurement region corresponding to the measurement region on the entire region of the display panel D.

More specifically, the matrix extracting unit 160 extracts the color space from the entire region of the display panel (D) by using the extracted color space transformation matrix for each measurement region, The color space conversion matrix can be extracted for the entire area of the display panel D by interpolating the conversion matrix.

At this time, the matrix extracting unit 160 according to another embodiment may use at least one of Linear Interpolation, Parbolic Interpolation, Newton Lagrange Interpolation, and Spline Interpolation It is possible to interpolate the color space conversion matrix for each measurement area into the color space conversion matrix for the entire area of the display panel D. [

The color space transformation matrix interpolated from the matrix extraction unit 160 according to another embodiment can be expressed by the following equation (8).

&Quot; (8) "

Wherein, M _{u, v} is the color space conversion matrix to the total area of the display _panel, m _{1,1 (u, v)} to about _3,3 m _{(u, v)} is an element of the color space transform matrix, u and v is the coordinate of the pixel location.

Up to now, the process of extracting chromaticity conversion coefficients and color space conversion matrix through the calibration step of the luminance and chromaticity measurement system 100 according to an embodiment of the present invention has been described.

The luminance and chrominance measurement system 100 according to an embodiment of the present invention extracts chrominance conversion coefficients and color space conversion matrices by extracting second color data from photographed images photographed by the camera 300, The luminance and chrominance measurement system according to another embodiment may extract the chromaticity conversion coefficient and the color space conversion matrix using the surface measurement color data measured from the surface measuring device instead of the second color data.

A luminance and chromaticity measuring system according to another embodiment and a luminance and chromaticity measuring system 100 according to an embodiment will be described in comparison with each other.

The meter driving unit of the luminance and chromaticity measuring system according to another embodiment may further include a surface measuring instrument for measuring the surface measuring color data in the entire area of the display panel D from which the surface measuring instrument outputs the plurality of patterns 1, .

Then, the meter driving unit according to another embodiment can extract only the surface measurement color data corresponding to the position information of the measurement areas 1, ..., P from the surface measurement color data.

The measured color data can be represented by a matrix expressed by the following equation (9).

&Quot; (9) "

Here, X _{N, P} 'is the triplet value of X' in the P th measurement region of the Nth pattern, Y _{N, P} ', Y' triplet value in the P th measurement region of the Nth pattern _, 'Is the triplet value of Z' in the Pth measurement region of the Nth pattern.

Here, the surface measurement color data measured by driving the surface measuring instrument by the meter driving unit may be the color coordinates (X _{N, P} ', Y _{N, P} ', Z _{N, P} ') in the CIE XYZ color space. At this time, the field meter may have a viewing angle, a viewing angle of the display panel D, and a vignetting phenomenon similar to the camera 300. As a result, the surface measurement color data of the surface measuring instrument measured in the same pattern and measurement area and the measurement color data of the point measuring instrument 200 are different from each other in the chromaticity and luminance difference as the data of the measurement area located at the edge of the display panel May occur.

Thereafter, the luminance and chromaticity measuring system according to another embodiment may perform the calibration step using the surface color data instead of the second color data in the same manner as the calibration step of the luminance and chromaticity measuring system 100 according to the embodiment have.

Accordingly, a description overlapping with the description of the luminance and chromaticity measurement system 100 according to the embodiment described above will be omitted.

Hereinafter, a process of performing the conversion step by the brightness and chromaticity measurement system 100 according to an embodiment of the present invention will be described.

8 is a diagram illustrating a camera 200 for photographing a luminance and chromaticity measurement system 100 according to an embodiment of the present invention and a display panel D for outputting a measurement image S. In FIG.

Referring to FIG. 8, the camera driving unit 130 may photograph the display panel D on which the measurement image S for measuring the luminance and chromaticity is outputted by driving the camera 200. Accordingly, the camera driving unit 130 can extract the first color data from the first captured image of the display panel D that outputs the measurement image S. More specifically, the camera driving unit 130 can extract the first color data for the entire area of the display panel D.

Here, the first color data may be the color coordinates (R _{u, v} , G _{u, v} , B _{u, v} ) in the RGB color space corresponding to the pixel position of the display panel D _, , 5) may be the color coordinates "R _1,5 , G _1,5 , B _1,5 " in the RGB color space.

At this time, if the first color data is represented by a matrix, it can be expressed by the following equation (10).

&Quot; (10) "

Wherein, R _{u, v} is the red value at the coordinates (u, v) of the pixel location, G _{u, v} is the green value at the position of the pixel position (u, v), B _{u, v} is the pixel location. Is the blue value at the coordinates (u, v).

The camera driver 130 may set the aperture value of the camera 300 and the ISO information to be the same as the aperture value of the calibration step and the ISO information at the time of photographing the display panel D that outputs the measurement image S. [

However, the camera driver 130 may set the exposure time of the camera 300 different from the exposure time of the calibration step according to the luminance of the measurement image S to be imaged. For example, the camera driving unit 130 may set the exposure time of the camera 300 to a long time exposure when the measurement image S to be imaged has low brightness. Conversely, when the measured image S to be imaged has high brightness, the camera driver 130 can set the exposure time of the camera 300 to short-time exposure. That is, the camera driver 130 can set the exposure time of the camera 300 in correspondence with the luminance of the measurement image S to be imaged.

The photographing distance L and the photographing height H at the time of photographing the display panel D outputting the measurement image S in the conversion step are the same as the photographing distance L during photographing of the display panel D in the above- And the photographing height H may be equal to each other.

The brightness and chromaticity measuring system 100 according to an exemplary embodiment can measure luminance and chromaticity by photographing a display panel D that outputs an arbitrary measurement image S, The system can measure the luminance and the chromaticity after driving the display panel D so that the measurement image S having the predetermined luminance and chromaticity is displayed using the panel driving unit.

Thus, the user of the luminance and chromaticity measurement system can confirm the measurement accuracy of the luminance and chromaticity measurement system by comparing the actually measured luminance and chromaticity with the mirror set luminance and chromaticity.

9 is a diagram showing the data flow between the configurations of the luminance and chromaticity measurement system 100 performing the conversion step.

Referring to FIG. 9, the coefficient extracting unit 140 may load the chromaticity transformation coefficients for each measurement region extracted in the calibration step from the storage unit DB, and interpolate the entire chromaticity of the display panel D.

More specifically, the coefficient extracting unit 140 interpolates the color space transformation matrix for an area in which the chroma conversion matrix is not extracted from the entire area of the display panel D using the chroma conversion coefficient for each measurement area, The chromaticity conversion coefficient can be extracted for the entire region of the image.

At this time, the coefficient extracting unit 140 interpolates chromaticity transformation coefficients for each measurement region into chromaticity transformation coefficients for the entire region of the display panel D using at least one of a linear interpolation method, a parabolic interpolation method, a Newter Lagrange interpolation method, and a spline interpolation method can do.

The chroma conversion coefficient interpolated by the coefficient extraction unit 140 can be expressed by the following equation (11).

Equation (11)

Here, (a _P, b _P, c _P) is a color conversion coefficient in the P-th measurement _{region, (a u, v, b} u, v, c u, v) are the coordinates are (u, v) of pixels Is the chromaticity conversion coefficient at the position.

Then, the coefficient extracting unit 140 extracts the exposure time of the second shot image obtained by photographing the pattern images 1, ..., P in the calibration step and the exposure time of the first shot image The chromaticity conversion coefficient can be corrected using the exposure time ratio between exposure times.

The reason why the time difference occurs between the exposure time of the second shot image and the exposure time of the first shot image will be described. In the present invention, the camera 300 displays the first shot image and the second shot image of the same exposure And takes a picture from the panel D. However, since the brightness of the pattern image 1, ..., P output from the display panel D is different from the brightness of the measurement image S, The exposure time is differently changed when the photographed image and the second photographed image are respectively photographed.

Accordingly, the coefficient extracting unit 140 can correct the chromaticity and luminance difference between the second color data and the first color data due to the difference between the exposure time of the second shot image and the exposure time of the first shot image.

At this time, the coefficient extracting unit 140 can correct the interpolated chroma conversion coefficient for the entire area of the display panel D using Equation (12) below.

&Quot; (12) "

_{Here, (a u, v ',} b u, v', c u, v ') is the corrected chrominance transform coefficients in a pixel location coordinates (u, v), (a u, v, b u, _v, c _{u, v)} are the coordinates are (u, v) is a color conversion coefficient before correction in a pixel location, E _cal is the exposure time of the second photographed image is taken in the calibration stage, E _mea is in the conversion step And the exposure time of the photographed first photographed image.

Then, the chroma converting unit 150 can convert the first color data into the first chroma data using the corrected chroma conversion coefficient. More specifically, the chroma converting unit 150 can convert the first color data into the first chroma data using the corrected chroma conversion coefficient and the sum of the components of the first color data.

(R _{u, v} , G _{u, v} , B _{u, v} ) in the RGB color space corresponding to the pixel position of the display panel D, as described above. The first chromaticity data converted from the first color data may also be the chromaticity coordinate (r _{u, v} , g _{u, v} , b _{u, v} ) of the rgb color space corresponding to the pixel position of the display panel (D).

At this time, the chroma converting unit 150 can convert the first color data into the first chroma data using the following equation (13).

&Quot; (13) "

Where, (r _{u, v,} g _{u, v,} b _{u, v)} is the sum coordinates are (u, v) in a first chroma data at pixel location, T ₃ is a component of the first color data, ( _{a u, v ', b u} , v', c u, v ') is the corrected chrominance transform coefficients in a pixel location coordinates (u, v), (R u, v, G u, v, b _{u, v} ) is the first color data at the pixel position with coordinates (u, v).

The color space conversion unit 170 may convert the color space of the converted first chroma data into standard chroma data of the standard color space. More specifically, the color space converting unit 170 may convert the first chroma data into the standard chroma data using the color space conversion matrix stored in the data storage unit DB.

Here, the standard color space may be the CIE xyz color space established in the CIE. That is, the color space conversion unit 170 can convert RGB color space, which is different for each camera 300, into standard chromaticity data of a CIE xyz color space, which is a standard color space in which different color spaces are defined. At this time, the standard chromaticity data may be the color coordinates (x _{u, v} , y _{u, v} , z _{u, v} ) on the CIE xyz color space.

Meanwhile, the color space transform unit 170 transforms the first chroma data into the standard chroma data using the interpolated color space transformation matrix for the entire region of the display panel D in the calibration step, It can be converted into chromaticity data.

At this time, the color space converting unit 170 may convert the first chroma data into the standard chroma data using Equation (14) below.

&Quot; (14) "

_{Here, (x u, v, y} u, v, z u, v) are the coordinates are (u, v) of a standard chrominance data at the pixel position, M _{u, v} of a color space for the entire area of the display panel (R _{u, v} , g _{u, v} , b _{u, v} ) is the first chrominance data at the pixel location with coordinates (u, v).

Next, the standard color conversion unit 180 can convert the standard chromaticity data into the standard color data using the component sum of the first chromaticity data. Here, the color space of the standard color data may be a CIE XYZ color space. That is, the standard color conversion unit 180 may convert the standard chromaticity data excluding the luminance component to the standard color data including both chromaticity and luminance components by multiplying the sum of the first chromaticity data.

At this time, the standard color converter 180 can convert the standard chroma data into the standard chroma data using Equation (15) below.

&Quot; (15) "

_{Here, (X u, v, Y} u, v, Z u, v) are the coordinates are (u, v) is the standard color data at the pixel position, T ₃ is the sum component of the first color data, (x _{u, v} , y _{u, v} , z _{u, v} ) are standard chromaticity data at pixel locations with coordinates (u, v).

Finally, the luminance and chrominance measurement system 100 according to an exemplary embodiment of the present invention multiplies the color conversion coefficient corrected for the first color data obtained from the first captured image by the color space conversion matrix, .

At this time, the luminance and chromaticity measurement system 100 can convert the standard color data from the first color data by using the following expression (16) summarizing the above-mentioned expressions (12) to (15).

&Quot; (16) "

_{Here, (x u, v, y} u, v, z u, v) are the coordinates are (u, v) of a standard chrominance data at the pixel position, M _{u, v} of a color space for the entire area of the display panel a transformation _{matrix, (a u, v ',} b u, v', c u, v ') is the corrected chrominance transform coefficients in a pixel location coordinates (u, v), (a u, v, b _{u, v, c u, v} ) is the chromaticity transform coefficients before the correction in the pixel location coordinates (u, v), E _cal is the exposure time of the second photographed image is taken in the calibration stage, E _mea converts The exposure time R _{u, v} , G _{u, v} , B _{u, v} of the first photographed image is the first color data at the pixel position whose coordinates are (u, v).

Accordingly, the luminance and chromaticity measurement system 100 can acquire standard color data at a pixel position having a coordinate (u, v) only by photographing once using the camera 300. [

In order to improve the accuracy of the finally converted standard color data, the standard color conversion unit 180 converts the reference color data obtained by measuring the display panel D, which outputs the measurement image S, So that the standard color data can be corrected.

More specifically, the point measuring instrument 200 can measure the reference color data at an arbitrary position on the display panel D, and correct the standard color data of the pixel position corresponding to the arbitrary position.

For example, if the correction of the standard color data (X _{15,25, 15,25} Y, Z _{15, 25)} are the coordinates on the display panel (D) in an arbitrary position (15, 25), for that pixel location. measuring a coordinate of (15, 25) the target data from the corresponding location on the display panel (D) to the _{(X 15,25 ", C 15,25"} , Z 15,25 ") as a point instrument 200, The standard color data can be corrected using the ratio of the standard color data and the reference color data at an arbitrary position.

At this time, the standard color converter 180 can correct the standard color data using Equation (18).

&Quot; (18) "

_{Here, (X u, v ',} Y u, v', Z u, v ') are the coordinates are (u, v) is the calibrated standard chrominance data at the pixel _{location, (X c1, c2 ",} Y c1 _{, c2 ", Z c1, c2} ") are the coordinates (c1, and the measured color data measured at the pixel location. c2) to point the instrument _{(200), (X c1,} c2, Y c1, c2, Z c1, c2 ) is the standard color data at the pixel position coordinates (c1, c2), (X u, v, Y u, v, Z u, v) are the coordinates are (u, v) the uncorrected standard at the pixel location. Chromaticity data.

The output unit 190 may output the Y tristimulus value having a coordinate of (u, v) among the color coordinates of the standard color data as a luminance value when the luminance is to be output at a pixel position with coordinates (u, v). The output unit 190 may output the chromaticity coordinates of the standard color data having the coordinates (u, v) when the chromaticity is to be output at the pixel position with coordinates (u, v).

Thus, the luminance and chromaticity measuring system 100 according to the present invention can output accurate luminance values and chromaticity values for each pixel position of the display panel D by taking a first shot image.

FIG. 10 is a flowchart illustrating a process of performing a calibration step of the luminance and chrominance measurement method according to an embodiment of the present invention.

Referring to FIG. 10, in order to perform the calibration step, the panel driver controls the display panel to output a pattern image on the display panel (S1010). Then, the meter driving unit measures the measured color data through the point meter in the measurement area of the display panel that outputs the pattern image (S1011), and the camera driver photographs the display panel that outputs the pattern image with the camera (S1012) The second color data is extracted from the photographed image (S1013).

The coefficient extraction unit extracts chromaticity conversion coefficients for approximating the second color data to the measured color data (S1014). Then, the chroma converting unit converts the second color data into the second chroma data using the chroma conversion coefficient and the sum of the second color data (S1015), and compares the measured color data with the measured chrominance data using the component sum of the measured color data Into data (S1016).

The matrix extraction unit extracts a color space transformation matrix for approximating the transformed measurement color data to the measurement chromaticity data (S1017).

Accordingly, in the method of measuring luminance and chrominance according to an exemplary embodiment, a color conversion coefficient for converting color data into chroma data and a color space conversion matrix for converting color space of chroma data can be extracted through a calibration step.

Hereinafter, a method of measuring luminance and chrominance according to an exemplary embodiment of the present invention includes the steps of extracting color data from a photographed image of a display panel through a conversion step and finally converting the color data into standard color data, Can be measured.

11 is a flowchart illustrating a process of performing a conversion step of the luminance and chrominance measurement method according to an embodiment of the present invention.

Referring to FIG. 11, the panel driver controls the display panel to output the measurement image to the display panel (S1110). The camera driving unit captures the display panel for outputting the measurement image with the camera (S1111), and extracts the first color data from the first captured image (S1112). The coefficient extraction unit interpolates the chroma conversion coefficients extracted in the calibration step using the interpolation method with respect to the entire area of the display panel (S1113), and compares the interpolated chroma conversion coefficients with the exposure time of the first captured image and the exposure time of the second captured image (S1114).

Thereafter, the chroma conversion unit converts the first color data into the first chroma data using the corrected chroma conversion coefficient and the sum of the first color data (S1115), and the color space conversion unit converts the color space conversion matrix The color space of the first chroma data is converted into the standard chroma data of the standard color space (S1116). The standard color conversion unit converts standard chromaticity data into standard color data using the sum of the first color data (S1117).

Then, the standard color conversion unit corrects the standard chromaticity data using the ratio between the reference chromaticity data measured in an arbitrary area of the display panel for outputting the measurement image and the standard chromaticity data of the pixel position corresponding to an arbitrary area (S1118) .

Finally, the output unit outputs the Y triplet value of the standard color data as the luminance value, calculates the ratio between the X triplet value, the Y triplet value, and the Z triplet value of the standard color data, and outputs the ratio as a chromaticity value (S1119).

Accordingly, the luminance and chrominance measurement method according to the present invention can output accurate luminance values and chromaticity values for each pixel position of the display panel by capturing a first shot image.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, But the present invention is not limited thereto.

Claims (16)

A chromaticity transforming unit for transforming the first color data extracted from the first captured image of the display panel for outputting the measurement image into the first chroma data using chroma conversion coefficients;
A color space conversion unit for converting the first chroma data into standard chroma data of a standard color space using a color space conversion matrix; And
And a standard color conversion unit for converting the standard chromaticity data into standard color data using the sum of the standard chromaticity data
Included luminance and chromaticity measurement system.
The method according to claim 1,
A coefficient extracting unit for extracting the chroma conversion coefficient for approximating the second color data extracted from the second captured image of the display panel for outputting the pattern image to the measured color data measured in the measurement area on the display panel
Further comprising a luminance and chromaticity measuring system.
3. The method of claim 2,
The coefficient extracting unit
And interpolates the chroma conversion coefficient corresponding to the measurement area on the entire area of the display panel.
3. The method of claim 2,
The coefficient extracting unit
Wherein the chroma conversion coefficient is corrected using an exposure time ratio between an exposure time of the first captured image and an exposure time of the second captured image.
3. The method of claim 2,
The chromaticity converting unit
And converting the second color data into second chroma data by using the chroma conversion coefficient and converting the measurement color data into measurement chroma data using the component sum of the measurement chroma data.
6. The method of claim 5,
And a matrix extraction unit for extracting the color space transformation matrix for approximating the second chroma data by the measurement chromaticity data
Further comprising a luminance and chromaticity measuring system.
6. The method of claim 5,
The matrix extracting unit
And the color space conversion matrix corresponding to the measurement area is interpolated on the entire area of the display panel.
The method according to claim 1,
The standard color conversion unit
And the standard color data is corrected using the data ratio between the reference color data measured in the measurement area on the display panel that outputs the measurement image and the standard color data.
Extracting chromaticity conversion coefficients and color space conversion matrices;
Capturing a display panel for outputting a measurement image to generate a first captured image, and extracting first color data from the first captured image;
Converting the first color data into first chroma data using the chroma conversion coefficient;
Converting the first chroma data into standard chroma data of a standard color space using the color space conversion matrix; And
Converting the standard chromaticity data into standard color data using the sum of the standard chromaticity data,
Including luminance and chroma measurement methods.
10. The method of claim 9,
The step of extracting the chroma conversion coefficient and the color space conversion matrix
Capturing a display panel for outputting a pattern image to generate a second captured image, and extracting second color data from the second captured image;
Measuring measured color data in a measurement area on the display panel; And
And extracting the chroma conversion coefficient for approximating the second color data to the measured color data
Including luminance and chroma measurement methods.
11. The method of claim 10,
The step of converting the first color data into the first chroma data
And correcting the chroma conversion factor using a ratio of exposure time between the exposure time of the first captured image and the exposure time of the second captured image
Including luminance and chroma measurement methods.
11. The method of claim 10,
The step of converting the first color data into the first chroma data
Interpolating the chroma conversion coefficient corresponding to the measurement area on the entire area of the display panel
Further comprising: measuring luminance and chromaticity.
10. The method of claim 9,
The step of extracting the chroma conversion coefficient and the color space conversion matrix
Converting the second color data into second chroma data by using the chroma conversion coefficient and converting the measured color data into measurement chroma data using the sum of the measured color data
Further comprising: measuring luminance and chromaticity.
11. The method of claim 10,
The step of extracting the chroma conversion coefficient and the color space conversion matrix
And extracting the color space transformation matrix for approximating the second chroma data by the measurement chromaticity data
Further comprising: measuring luminance and chromaticity.
11. The method of claim 10,
The step of converting the standard chromaticity data into the standard color data includes:
Converting the first chroma data into standard chroma data in a standard color space
Interpolating the color space transformation matrix corresponding to the measurement area on the entire area of the display panel
Further comprising: measuring luminance and chromaticity.
9. The method of claim 8,
And correcting the standard color data using the data ratio between the reference color data measured in the measurement area on the display panel for outputting the measurement image and the standard color data
Further comprising: measuring luminance and chromaticity.

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