KR20050059522A - Method and apparatus for correcting image displaying device - Google Patents

Abstract

The present invention relates to a color correction method and apparatus for an image display device in which a display image that varies depending on ambient lighting or surrounding environment is made identical to an actual image by using the color adaptation phenomenon of the human visual system and the corresponding color principle.

The color correction method and apparatus of the video display device determine the acclimatized white point of the eye conformed to the ambient light and make the display image reproduced on the video display device look the same as the original image based on the compliance white. Correct the input data.

Description

Color correction method and apparatus of an image display device {Method and Apparatus For Correcting Image Displaying Device}

The present invention relates to an image display device, and more particularly, to a color correction method of an image display device in which a display image that varies depending on an ambient light or an environment using the color adaptation phenomenon and the corresponding color principle of a human visual system is identical to an actual image. And to an apparatus.

Display images on a television (Television, TV) or personal computer (Personal Computer, PC) monitor are required to have high definition and high definition. In response, thanks to the development of digital circuit technology and image display devices, high-definition and high-definition images of physical aspects can be reached. However, there is a significant difference between the color of the natural image and the color reproduced in the display device. Accordingly, research is being conducted to match the color reproduced between the actual color in the natural image and the color reproduced in the image display device and the image reproduced between the image display elements.

In today's information society, display elements are more important than ever as visual information transfer media. Cathode ray tubes or cathode ray tubes, which are currently mainstream, have problems with weight and volume.

Flat display panels (FPDs), which can solve the shortcomings of conventional cathode ray tubes (CRTs), have been in the spotlight. The flat panel display device includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescence (EL). Most are commercially available and commercially available.

Liquid crystal displays (LCDs) are thin, light and have high quality, high resolution, low power consumption, and are being used as various display devices such as televisions and personal computers, and are rapidly replacing cathode ray tubes. However, in terms of color reproducibility, the physical and electro-optical properties of liquid crystals still fall short of the performance of conventional cathode ray tubes.

Cathode ray tube has almost no change in the chromaticity coordinates of the three primary colors and the correlated color termperature (CCT) of the gray scale according to the change of the input values of the three primary colors of RGB. The color change occurs largely according to the input digital value of, and accurate color reproduction is difficult. For example, in a liquid crystal display, as the input digital value is lower, the correlated color temperature of the gray level increases, so that the darker the color tone of the display image, the slightly bluer the color. Many studies have been made to improve the color expression ability of the liquid crystal display, but the results of the research are not satisfactory. In the case of "Color reproduction varying the input level on a liquid crystal display panel" presented by Yukio Okano in November 1999 at The Seventh Color Imaging Conference, a lookup that corrects only blue (B) data in RGB digital values of the liquid crystal display. The gray level is improved by using a look-up table (LUT), but since only the blue data is corrected, the change in the correlated color temperature and coordinates remains in the gray level, and deterioration of luminance characteristics is caused by simply reducing the blue data. There is a problem. In this way, the existing color correction method adjusts the brightness and color by considering only the aspect of visual recognition and the signal correction without considering the corresponding color recognition characteristics of human vision. The color difference is inevitable.

In color image display, a colorimetric method of reproducing stimulus values proportional to the original subject for color reproduction in standard viewing conditions, and a preferred color for a specific color such as flesh color or leaf color ( The color reproduction method which uses the prefered color reproduction method has been studied. However, the actual viewing environment using the color image display device may be quite different from the standard viewing environment. In fact, when using a color image display device such as a monitor of a television or personal computer in a normal home or office, it is used during the day when the natural light used under natural light or under night light such as incandescent and fluorescent light. Due to this difference in visual environment, the color gamut in which the gain ratio of cone cells L (long), M (middle), and S (short), which distinguishes colors into three types of 555, 530, and 455 nm, respectively, is different in the human visual system. chromatic adaptation phenomenon. Due to this color adaptation phenomenon, the user may feel different colors reproduced in the color image display apparatus. Therefore, even when the visual environment is different from the standard visual environment, there is an urgent need for a method for displaying an image reproduced by the color image display device in the same color as the original subject.

In general, the color change on the color image display device felt by the user is mainly due to the color adaptation phenomenon of the human vision caused by the change in the chromaticity of the surroundings by the ambient illumination light. Therefore, if the stimulus values of the colors reproduced in the color image display apparatus are considered only in consideration of the color adaptation characteristics of the visual environment due to the surrounding environment, the colors reproduced in the color image display apparatus may be displayed as the colors of the original subjects.

Various models have been proposed as a method of reproducing the corresponding color in consideration of the color adaptation characteristics of human vision. For example, corresponding color reproduction models, such as the von Kries model and the Breneman model, use a linear adaptation transformation that assumes a linear change in the proportional coefficient ratio of human vision from color adaptation under a particular illumination to color adaptation under another illumination. . Nonlinear compliance models, such as Bartleson, Fairchild, and CIECAM97s (CIE Color Appearance Model 97 simpified), which predicted the corresponding color by assuming a nonlinear change in the stimulus value of human vision.

The von Kries model and the Breneman's corresponding color reproduction model using the linear adaptation function have excellent prediction of the corresponding color when the ambient luminance is high, but increase the error of the prediction color in the environment where the ambient luminance is low. The Bartleson model reproduces the corresponding color well where the ambient luminance is low, but the reproduction error increases where the ambient luminance is high, especially in the blue chromaticity. The Fairchild model, which is developed for the reproduction of corresponding colors in reflectors such as prints, has complicated calculations using nonlinear compliance functions. In addition, the CIECAM 97s model has the disadvantage that the calculation is very complicated and the color reproduction error is larger than that of the von Kries model.

On the other hand, the Republic of Korea Patent Publication No. 1996-0009622 is divided into the data environment mode unit according to the external environment in advance and stored in advance, the color of the color detected by the three-color sensor of RGB compared with the stored image environment mode data current environment After judging, a method of displaying an image with correction data based on previously stored data has been proposed. However, this method also has a limitation in color correction because it does not consider the color adaptation phenomenon and the corresponding color principle of the human visual system and cannot store optimal correction data for all image environments.

Accordingly, an object of the present invention is to provide a color correction method and apparatus for an image display apparatus in which a display image that varies depending on ambient light or surrounding environment is made identical to an actual image by using the color adaptation phenomenon of the human visual system and the corresponding color principle. Is in.

In order to achieve the above object, the color correction method of the image display device according to an embodiment of the present invention comprises the steps of sensing the ambient illumination light; Determining a compliant white point of the eye adapted by the ambient illumination light; Correcting the input data with a corresponding color such that the display image reproduced in the image display apparatus looks the same as the original image based on the compliant white; And reproducing the corresponding color data on the image display apparatus.

The detecting of the ambient illumination light may include sensing yellow light of the ambient illumination light and outputting a yellow detection voltage corresponding thereto; Sensing cyan light of the ambient illumination light and outputting a cyan light detection voltage corresponding thereto; Calculating a ratio of the yellow sense voltage to the cyan sense voltage and comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data; Determining the ambient illumination light according to the comparison result.

The determining of the compliant white point may be performed by using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and Equations 1 and 2 below. The compliance white point W _E (u _E , v _E ) is determined.

------------- Formula (1)

------------- Formula (2)

Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037

Compensating the input data with the corresponding color includes calculating an XYZ stimulus value of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; The step of using the L _a M _a S _a predetermined proportional coefficient and the input data of the magnetic pole teeth of the magnetic pole teeth XYZ generate corresponding color data in the XYZ stimulus and; Converting corresponding color data of the XYZ stimulus values into RGB data.

The stimulus value after the color adaptation is shown in Equations 3 to 5 below.

L _a = k _L L ------------- Formula (3)

M _a = k _M M ------------- Formula (4)

S _a = (k _S ) ^P S ------------- Formula (5)

Where L, M and S are eye stimulus values for the original image, k _L , k _M , k _S are proportional coefficients between the stimulus values of the eye after the original image and the color adaptation, and P is the luminance change of the original image. Is a factor that ensures that there is a minimum error between different illumination light environments.

The proportional coefficients k _L , k _M , k _S are as shown in Equations 6 to 8 below.

k _L = L _max2 / L _max1 ------------- Equation (6)

k _M = M _max2 / M _max1 ------------- Equation (7)

k _S = S _max2 / S _max1 ------------- Equation (8)

Where L _max1 , M _max1 , S _max1 is an eye stimulus obtained from the white or the maximum stimulus of the original image, and L _max2 , M _max2 , S _max2 is an eye irritation value obtained at an acclimatized white point of the eye adapted by the ambient illumination light and the image display apparatus.

The coefficient P is the same as Equations 9 and 10 below.

P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )

  ------------- Formula (9)

P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )

  ------------- Formula (10)

Where Y is luminance.

The relationship between the L _a M _a S _a stimulus value and the XYZ stimulus value is shown in Equation 11 below.

max1 max1, max2 W _E

  ------------- Formula (11)

Where X _max1 , Y _max1 , Z _max1 is the XYZ stimulus obtained from the white or maximum stimulus of the original image, L _max1 , M _max1 , S _max1 is the LMS stimulus obtained from the white or maximum stimulus of the original image, L _max2 , M _max2 , S _max2 is the stimulus value obtained at the compliance white point of the eye, which is adapted by the ambient illumination light and the image display device, and W _E is the compliance white of the eye.

Corresponding color data of the XYZ stimulus values is calculated by Equation 12 below.

------------- Formula (12)

Here, X ₁ , Y ₁ , and Z ₁ are eye irritation values for the original image, and X ₂ , Y ₂ , and Z ₂ are eye irritation values for the corresponding color.

According to another aspect of the present invention, there is provided a method of correcting a color of an image display device, the method including sensing ambient illumination light; Determining a compliant white point of the eye adapted by the ambient illumination light; Correcting the input data with a corresponding color such that the display image reproduced in the image display apparatus looks the same as the original image based on the compliant white; Correcting a correlated color temperature with respect to the corresponding color data; And reproducing the corrected color and the correlated color temperature data on the image display apparatus.

Correcting the correlated color temperature adjusts the correlated color temperature of the corresponding color data within the range of 6500K ± 100K.

Correcting the correlation color temperature increases the value of red data and decreases the value of blue data in the corresponding color data.

Correcting the correlated color temperature corrects the correlated color temperature by linear interpolation.

In the correcting of the correlated color temperature, the correlated color temperature is not corrected for the corresponding color data corresponding to the maximum and minimum values of the input data.

A color correction method of an image display apparatus according to another embodiment of the present invention includes the steps of checking the current operation mode; Sensing ambient illumination light; If the operation mode is the automatic mode, the display apparatus reproduces the display image reproduced by the image display apparatus by using a preset corresponding color reproduction model by determining the acclimatized white point of the eye adapted by the ambient illumination light. Generating 1 corresponding color data; If the operation mode is the manual mode, the display image reproduced by the image display apparatus is determined by determining the acclimatized white point of the eye conformed by the ambient illumination light and using the corresponding color reproduction model selected by the user among the corresponding color reproduction models. Generating second corresponding color data to look the same as the image; Selectively correcting a correlated color temperature with respect to said first and second corresponding color data; And reproducing any one of the first and second corresponding color data and the data whose correlated color temperature is corrected on the image display apparatus.

The generating of the first corresponding color data may include calculating an XYZ stimulus value of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; The step of using the L _a M _a S _a predetermined proportional coefficient and the input data of the magnetic pole teeth of the magnetic pole teeth XYZ generate corresponding color data in the XYZ stimulus and; Converting corresponding color data of the XYZ stimulus values into RGB data.

The plurality of corresponding color reproduction models, the corresponding color reproduction model, von Kries corresponding color reproduction model, Breneman corresponding color reproduction model, Bartleson corresponding color reproduction model, Fairchild corresponding color reproduction model, and CIECAM97s corresponding color reproduction model defined by Equation 12 It includes.

A color compensating device of an image display device according to an embodiment of the present invention includes a sensing unit for sensing ambient illumination light; A correction processor configured to determine a conforming white point of the eye adapted by the ambient illumination light and to correct the input data with a corresponding color such that the display image reproduced by the image display apparatus looks the same as the original image based on the conformal white; And a display control unit which reproduces the corresponding color data on the video display device.

The sensing unit detects the yellow light of the ambient illumination light and outputs a yellow detection voltage corresponding thereto, and detects cyan light of the ambient illumination light and outputs a cyan detection voltage corresponding thereto; And an analog / digital converter configured to convert each of the yellow sense voltage and the cyan sense voltage into digital data.

The correction processor calculates a ratio of the yellow detection voltage and the cyan detection voltage converted into the digital data, compares the voltage ratio with pre-stored ambient illumination light source to voltage ratio data, and determines the ambient illumination light according to the comparison result. .

The correction processing unit uses the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the compliant white point W using Equations 1 and 2 above. Determine _E (u _E , v _E ).

The correction processing unit calculates an XYZ stimulus value of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; Wherein by using a predetermined proportional coefficient and the input data of the XYZ stimulus for _a L _a M _a magnetic pole S generates a corresponding color data in the XYZ stimulus; Corresponding color data of the XYZ stimulus values is converted into RGB data.

According to another aspect of the present invention, there is provided a color compensating apparatus for an image display device, including: a sensing unit configured to sense ambient illumination light; Determining an acclimatized white point of the eye adapted by the ambient illumination light, and correcting the input data with a corresponding color such that the display image reproduced on the image display apparatus looks the same as the original image based on the compliance white; A correction processing unit for correcting a correlated color temperature with respect to the correlation; And a display control unit for reproducing the corrected color and the correlated color temperature data on the image display device.

The correction processor adjusts the correlated color temperature of the corresponding color data within the range of 6500K ± 100K.

The correction processor increases the value of the red data in the corresponding color data and decreases the value of the blue data.

The correction processing unit corrects the correlated color temperature by linear interpolation.

The correction processor does not correct the correlated color temperature for the corresponding color data corresponding to the maximum and minimum values of the input data.

According to still another aspect of the present invention, there is provided a color compensating apparatus for an image display device, including: a sensing unit configured to sense ambient illumination light; If the current operation mode is checked and the operation mode is the automatic mode, the display image reproduced by the image display apparatus is determined by determining the acclimatized white point of the eye conformed by the ambient illumination light and using one preset color reproduction model. A first correction processor for generating first corresponding color data to make the image look the same as the image; If the operation mode is the manual mode, the display image reproduced by the image display apparatus is determined by determining the acclimatized white point of the eye conformed by the ambient illumination light and using the corresponding color reproduction model selected by the user among the corresponding color reproduction models. A second correction processor for displaying second corresponding color data to make the image look the same as the image; A third correction processor for selectively correcting a correlated color temperature with respect to the first and second corresponding color data; And a display control unit which reproduces any one of the first and second corresponding color data and the data whose correlated color temperature is corrected on the image display device.

The image display device is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescent device (EL).

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 1 to 26.

Referring to FIG. 1, an image display device according to an exemplary embodiment of the present invention determines an optical sensing unit 1 for detecting ambient illumination light, determines a conforming white point by ambient illumination light, and processes corresponding color correction and correlation color temperature correction. And a control unit 5 for supplying the data corrected by the correction processing unit 3 to the image display element 6.

The light detector 1 detects ambient illumination light using two sensors, a yellow light sensor and a cyan light sensor. The analog voltage output from the light detecting unit 1 is converted into digital data by the analog / digital converting unit (hereinafter referred to as "A / D converting unit") 2 and supplied to the correction processing unit 3. .

The correction processing unit 3 amplifies the voltage from the A / D converter 2 and calculates the output voltage ratio Ye / Cy between the output of the yellow light sensor and the output of the cyan light sensor, and the output voltage ratio Ye / Cy) is compared with previously stored illumination light source to voltage ratio data to determine the color temperature of the ambient illumination light. The correction processing unit 3 then calculates a compliance white point of the eye adapted to the determined ambient illumination light and calculates the corresponding color at the compliance white point. The correction processing unit 3 also corrects the correlated color temperature with respect to the corresponding color correction data. The output voltage ratio Ye / Cy calculation, the compliance white point calculation, the corresponding color calculation and the correlation color correction of the light sensing unit 1 are processed in the automatic mode or the manual mode. That is, in the automatic mode, the output voltage ratio (Ye / Cy) calculation, the compliance white point calculation, and the corresponding color calculation of the light sensing unit 1 are automatically performed by a preset algorithm, and optionally the correlation color correction for the corresponding color data is performed. This is done automatically. In the manual mode, corresponding color calculation is performed according to a user command input through a user interface such as an on-screen display or a remote controller, and a correlated color temperature correction is optionally processed.

The controller 5 supplies the input digital video data RoGoBo from the input signal processor 4 to the correction processor 3 and corrects the data (RoGoBo) corrected by the correction processor 3, that is, corresponding color correction data or correspondence. Color & correlation color temperature correction data is reproduced on the image display element 6. The input signal processing unit 5 supplies data, which has been subjected to graphic processing such as noise reduction, signal interpolation, resolution conversion, etc. to the television received image or digital video data input from a computer, to the controller 4 via an interface circuit.

2 shows an example of the output voltage ratio Ye / Cy between the output of the yellow light sensor and the output of the cyan light sensor for representative light sources. When each of the yellow light sensor and the cyan light sensor is implemented as “AM-32-CY-02,” the output voltage ratio Ye / Cy of the two light sensors is different for each representative light source as shown in FIG. 2. For example, with different illumination levels of 650 lx, 950 lx, 1250 lx, 1550 lx and 2000 lx, the output voltage ratio (Ye / Cy) between the output of the yellow light sensor and the output of the cyan light sensor is approximately 1.54 for the A light source. And about 0.86 for D ₆₅ light sources. Therefore, the output voltage ratio Ye / Cy between the two light sensors is constant for each representative light source regardless of illuminance of the illumination light. The ambient illumination light using the image display device 6 may be determined by the output voltage ratio Ye / Cy between the two light sensors, and the classification data of the ambient illumination light corresponding to the output voltage ratio Ye / Cy is corrected. It is stored in the processing unit 3. Table 1 below shows the output voltage ratio (Ye / Cy) of the optical sensor to the reference white and the ambient illumination light source of the image display device. As can be seen from Table 1, the incandescent lamp which is used most as ambient light has about 1.5 output voltage ratio (Ye / Cy) of the two sensors and about 1.0 output voltage ratio (Ye / Cy) of the two sensors. That is, the ambient illumination light source may be classified by the output voltage ratio Ye / Cy of the two sensors.

Reference White and Ambient Light Sources of Image Display Devices Ye / Cy D ₆₅ 0.924 9300K + 27MPCD 0.813 Incandescent light 1.501 Fluorescent lamp 1.025

The output voltage ratio Ye / Cy of the two sensors is preferably set in a range so that each illumination light source can be accurately distinguished without conflicting between the respective illumination light sources. An example is shown in FIG. 3 and Table 2. FIG.

Illumination D ₇₅ D ₆₅ D ₅₀ CWF A Range (R) R = 0.84 0.84 <R = 0.94 0.94 <R = 1.15 1.13 <R = 1.38 R> 1.38

3 is a flowchart showing step by step a control procedure of a color correction method of an image display device according to an exemplary embodiment of the present invention.

Referring to FIG. 3, in the color correction method of the image display apparatus according to the present invention, the output of the yellow light sensor and the output of the cyan light sensor are input as digital values, and the automatic mode or the manual mode is determined. (S1, S2)

In the automatic mode, the correction processing unit 3 calculates the output voltage ratio Ye / Cy of the optical sensors periodically, for example, at a period of 2 sec, and determines the ambient illumination light source according to the set range as shown in FIGS. 3 and 2. S3) Then, the correction processing unit 3 determines the compliance white point of the eye by the white of the ambient illumination light and the white of the image display element, and calculates the corresponding color data in consideration of the compliance white point as a preset optimal correspondence color reproduction model. The correlated color temperature is corrected according to the user's selection for the corresponding color data (S3, S4, S5, S10, S11).

In the manual mode, the correction processor 3 calculates the output voltage ratio Ye / Cy of the optical sensors according to a user command received through the on-screen display or the remote controller, and calculates the ambient light source according to the set range as shown in FIGS. 3 and 2. (S6) Then, the correction processing unit 3 determines the compliance white point of the eye based on the white of the ambient illumination light and the white of the image display element, and sets the corresponding color data in consideration of the compliance white point in advance. The corresponding color reproduction model selected by the user among the reproduction models is calculated, and the correlated color temperature is corrected according to the user's selection with respect to the corresponding color data. (S6, S7, S8, S9, S10, and S11) Steps S5 and S8 of FIG. In the step, the correction processing unit 3 performs linear adaptation conversion models such as known "von Kries corresponding color reproduction model" and "Breneman corresponding color reproduction model", and known "Bartleson corresponding color reproduction model", " The corresponding color reproduction model is selected for nonlinear conformation models such as "Fairchild corresponding color reproduction model" and "CIECAM97s corresponding color reproduction model", and the optimum corresponding color reproduction model proposed in the present invention.

[Calculation of Compliance White Point]

When using a color image display device in an indoor environment, the user's vision is adapted by the chromaticity and luminance components of the mixed light source of the illumination light reflected directly from the illumination light or the wall as shown in FIG. 5 and the light of the image display device itself. .

N. Moroney, "Model Based Color Toleransce," Proceeding of the 7th IS & T / SID Color Imaging Conference, pp.93-99, Nov 1999 and Peyma Oskoui, Elizabeth Pirrotta, "MND-A New Psychophysical Algorithm for Determiantion of Chromatic Adaptation, '' Technical report of Hewlett Packard, Dec. As known from 1999, when the color temperature of the compliant white point of the eye is slightly different, the user who views the display image of the image display apparatus recognizes the color different from the actual display image.

R.W.G. Hunt and Miss L. M. Winter, "Colour Adaptation in Picture-Viewing Situations," J. of Photographic Science, vol. 23, pp. 112-115, 1975 shows that the acclimatized white point of the eye by the two types of mixed illumination light tends to move in the direction of the ambient illumination light coordinate according to the illuminance of the incandescent light in the uv coordinate system. It has been found that the conforming white point of is on a straight line connecting the two light sources. In this experiment, the incandescent lamp having a correlated color temperature of about 2900K was irradiated to the observer's front screen as shown in FIG. An arbitrary image is displayed on an image display device, and an observer views the image, and then irradiates the white eyes with respect to illuminance of various incandescent lamps.

As a result of the experiment, when the observer stares at the display image under incandescent lighting, the change of the observer's eye white coordinate according to the incandescent illumination is shown in FIG. 7. In FIG. 7, '*' is a reference white coordinate of the image display apparatus, and '●' is an average color coordinate of the image display apparatus used for the experiment. The average color coordinate of this image display device is almost similar to the reference white coordinate of the image display device. '▲' is the white coordinate of the eye that is adapted to the intensity of incandescent light. As can be seen in FIG. 7, when an observer gazes at the display image under incandescent lighting, the compliant white of the eye is placed between the D ₆₅ light source, the reference white of the image display device, and the coordinates of the ambient illumination light.

The color correction method of the image display device according to the present invention is based on the eye of any brightness L of the illumination light with the Euclidian distance from the white coordinate point of the image display device to the incandescent light coordinate point in FIG. We modeled the percentage of compliant white coordinate points on the distance between the white coordinate points and the incandescent light coordinate points of the image display device. As a result, the compliant white coordinates of the eye by the ambient illumination light and the image display device are obtained by equations (1) and (2) as a function of the luminance L of the ambient illumination light source.

, Δu = u _L -u _D

, Δv = v _L -v _D

Here, W _L (u _L , v _L ) is the white coordinate of the ambient light source, and W _D (u _D , v _D ) is the white coordinate of the image display device. And W _E (u _E , v _E ) is the adaptive white coordinate of the eye. The parameter values a, b and c are a = 0.571, b = -0.445 and c = 0.037 as calculated by the least error square method.

Table 3 shows chromaticity coordinates for the case where the ambient light source uses an incandescent lamp and a fluorescent lamp, and the white of the image display device is D ₆₅ and 9300K + 27MPCD. When the white coordinates of the eye according to the luminance of the ambient illumination light under the conditions of Table 3 are obtained using Equations 1 and 2, they are shown in Table 4 and FIGS. 8A and 8B.

Each of the "von Kries model", "Breneman model", "Bartleson model", "Fairchild model", "CIECAM97s model", and the optimal corresponding color reproduction model proposed in the present invention are selected in the steps S5 and S8 of FIG. The summary is as follows.

[von Kies-adaptive color reproduction model]

Corresponding color prediction in the von Kries corresponding color reproduction model is described by equations (3) to (13).

L _a = k _L L

M _a = k _M M

S _a = k _S S

In Equations 1 to 3, L, M, and S are the stimulus values of the observer's vision with respect to the original image of the observer, and L _a , M _a , and S _a are the visual appearing after the eye color adaptation in the second visual environment. The stimulus value of. And k _L , k _M , and k _S are proportional coefficients between visual stimulus values when the observer observes the original image and the image after compliance. These proportional coefficients are obtained from the white stimulus values L _white , M _white , S _white or the maximum stimulus values L _MAX , M _MAX , S _MAX of the original subject as shown in Equations 6 to 8 below.

k _L = 1 / L _MAX or k _L = 1 / L _white

k _M = 1 / M _MAX or k _M = 1 / M _white

k _S = 1 / S _MAX or k _S = 1 / S _white

The equations of the von Kries model for calculating the corresponding colors in different viewing environments are shown in Equations 9-11.

L ₂ = (L ₁ / L _MAX1 ) L _MAX2

M ₂ = (M ₁ / M _MAX1 ) M _MAX2

S ₂ = (S ₁ / S _MAX1 ) S _MAX2

The relationship between the LMS stimulus and CIE 1931 XYZ stimulus of human visual cones based on the von Kries corresponding color reproduction model is shown in Equation 12.

,

The stimulus values X ₁ , Y ₁ , and Z ₁ of the original subject are calculated by the corresponding color stimulus values X ₂ , Y ₂ , and Z ₂ as in Equation (11).

,

[Breneman-adaptive color reproduction model]

Corresponding color prediction in the Breneman corresponding color reproduction model is described by equations (14) to (18). In the Breneman-adaptive color reproduction model, the stimulus values when the human vision is adapted to the ambient light source are linear proportional coefficients α, β, and Has

P ′ = αP

D '= βD

T

Here, P, D, and T are visual stimulus values of the eye adapted in the previous environment, and P ', D', and T 'are eye stimulus values that are adapted to the eye in an environment to reproduce the corresponding color. The conversion equation between the visual stimulus PDT and XYZ is expressed by Equation 15.

, or ,

The values of X ', Y', and Z 'after the eye is adapted to the surrounding environment at the XYZ stimulus values are obtained by substituting Equation 15 into Equations 12 to 14 as follows.

, or

[Bartleson-adaptive color reproduction model]

Corresponding color prediction in the Bartleson corresponding color reproduction model is described by equations (19) to (28).

L _a = a _L L

M _a = a _M M

S _a = k (a _S S) ^Ρ

Here, the conversion from X, Y, and Z to L, M, and S is as in Equations 22 to 24.

L = 0.0713 (X / Y) + 0.9625 (Y / Y)-0.0147 (Z / Y)

M = -0.3925 (X / Y) + 1.1668 (Y / Y) + 0.0815 (Z / Y)

S = 0.5610 (Z / Y)

In Equation 21, the power P and the proportional coefficient k of the S channel are given by Equations 25 and 26.

P = 0.326 (a _L ) ^27.45 + 0.325 (a _M ) ^-3.91 + 0.340 (a _S ) ^-0.45

k = a _S S / (a _S S) ^P

The x, y coordinates from the stimulus values L _a , M _a , and S _a of the corresponding color for any color are as shown in Equations 27 and 28.

Here, l _a and m _a are given by l _a = L _a / (L _a + M _a + S _a ) and m _a = M _a / (L _a + M _a + S _a ).

[Fairchild-adaptive color reproduction model]

Corresponding color prediction in the Fairchild corresponding color reproduction model is described by equations (29) to (35).

,

Here, L ₁ , M ₁ and S ₁ are stimulus values of human vision.

,

For L and S, α and P are given in the same manner as in Equations 28 and 29. Where α and P are the sensitivity to cone cells in human vision. The variable Y _n represents the luminance value of the adaptive environment. n denotes the adaptive environment and subscript E in the variable denotes an equal-energy light source. And the variable υ is used as 1/3. Using L ₁ ′, M ₁ ′, and S ₁ ′, the stimulus values of human vision according to the luminance change in the visual environment can be derived as follows.

,

Where c is defined as c = 0.219-0.0784log ₁₀ (Y _n ).

The C ₁ matrix derives a value considering the change in luminance of the visual environment. Therefore, the stimulus value of X ₂ Y ₂ Z ₂ , which should be the sample color in the second environment, can be expressed as follows using Equations 29 to 34.

[CIECAM97s-adaptive color reproduction model]

Corresponding color prediction in the CIECAM97s corresponding color reproduction model is described by equations (36) to (47). Based on this CIECAM97s corresponding color reproduction model, the input parameters for the corresponding color reproduction are luminance L _A in compliant environment, tristimulus value XYZ of subject in original environment, tristimulus value X _W Y _W Z _W , in original environment. Correlation luminance Y _b of the subject background in the original environment. The variables according to the city environment are the influence of the surroundings c and the factor F indicating the degree of compliance.

The RGB stimulus value of human vision with respect to the original subject in the compliant environment can be expressed by Equation 36 using the XYZ stimulus value luminance ratio.

,

The reflected visual stimulus R _c G _c B _c in Equation 37 to 39 is calculated based on the RGB visual stimulus value obtained from the original subject and reflecting the degree of compliance with the visual environment.

R _c = [D (1.0 / R _W ) + 1-D] R

G _c = [D (1.0 / G _W ) + 1-D] G

Here, R _W G _W B _W is the stimulus value at the time of the light source or white at the original subject, and the absolute value is used when the value of the B stimulus value is negative. The coefficients D and the coefficient P representing the degree of compliance with the visual environment of human vision are defined by Equations 40 and 41.

P = (B _W /1.0) ^0.0834

The degree of visual adaptation, D, to the ambient visual environment has a value of 1.0 when fully conformed. In addition, the coefficient values k and F _L are used for the effect of the background of the subject when looking at the original subject in the first visual environment.

k = 1 / (5L _A +1)

F _L = 0.2k ⁴ (5L _A ) +0.1 (1-k ⁴ ) ² (5L _A ) ^1/3

The visual compliance stimulus in the second visual environment can be calculated using the cone cell stimulus response curve obtained by Hunt-Pointer-Estevez. The stimulus of visual compliance in the second visual environment is shown in Equation 44 below.

,

In consideration of the adaptive stimulus value of Equation 44 and the background influence, the stimulus value of the time of the corresponding color in the second visual environment is calculated as shown in Equations 45 to 47 below.

[Optimized Color Reproduction Model]

Equations 48 to 53 will be described with reference to the corresponding color prediction of the optimal corresponding color reproduction model.

S _a = (k _S ) ^P S

Equation 48 shows the stimulus value Sa of S corresponding to blue among the stimulus values of the time appearing after the eye color adaptation in the second visual environment. On the other hand, the stimulus values L _a and M _a of L and M corresponding to red and green among the stimulus values of the time appearing after the eye color adaptation in the second visual environment are the same as Equations 3 and 4. In Equations 3, 4 and 48, k _L , k _M and k _S are proportional coefficients between visual stimulus values when the observer observes the original image and the image after the acclimation. That is, these proportional coefficients are coefficient values for matching different illumination light environments. These proportional coefficients are obtained from the maximum stimulus values L _MAX , M _MAX , and S _MAX in different light tube environments as shown in Equations 6 to 8 below.

k _L = L _max2 / L _max1

k _M = M _max2 / M _max1

k _S = S _max2 / S _max1

Where L _max1 , M _max1 , S _max1 is the stimulus value obtained from white or maximum stimulus of the original subject, and L _max2 , M _max2 , S _max2 is the stimulus value of the eye obtained from the acclimatized white point of the eye, which is acclimated by the ambient illumination light and the image display device light source.

The power P of the proportional coefficient k _S corresponding to blue is experimentally determined to have a minimum error between different illumination light environments with respect to a change in luminance of the original image. This variable P is shown in Table 5 and FIG. Using the experimental value of the coefficient P, the coefficient P obtained as an approximation equation is represented by Equation 52.

P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )

P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )

Equation 53 below represents L _max1 , M _max1 , and The relationship between LMS stimulus and XYZ stimulus for S _max1 , L _max2 , M _{max2, and} S _max12 .

max1 max1, max2 W _E

Where W _E is the compliant white of the eye.

The stimulus values X ₁ , Y ₁ , and Z ₁ of the original subject are calculated by the corresponding color stimulus values X ₂ , Y ₂ , and Z ₂ as in Equation 54.

Experimental results show that the optimum color reproduction model according to the present invention has a smaller color reproduction error than conventional color reproduction models. This experiment is described as follows.

The target color models for this experiment were the "von Kries model", the "Breneman model", the "Bartleson model", the "Fairchild model", the "CIECAM97s model", and the optimum corresponding color reproduction model. The experimental data used for the experiments are the corresponding color data of Tables 6 to 8 obtained in Breneman's experiment.

(Continued Table 6)

For quantitative performance evaluation between corresponding color reproduction models, colorimetric error in u'v 'coordinate system and color reproduction error in L ^* u ^* v ^* coordinate system were calculated.

The colorimetric coordinate error between the predicted color and the corresponding color in the u'v 'coordinate system is calculated by Equation 55.

Here, (u ₂ ′ v ₂ ′) is the color coordinate of the predicted color, and (u _a ′ v _a ′) is the color coordinate of the corresponding color. And N is the number of samples used in the experiment. Corresponding colors obtained using Breneman's corresponding color data (AD ₆₅ , 1500cd / m ² ) are shown in FIG. 10 in the u′v ′ coordinate system. In Fig. 10, the symbol '○' is a coordinate value in the D ₆₅ light source, and '△' is a corresponding color coordinate after being adapted to the A light source. '▲' is the predicted color predicted using the best match color reproduction model. The average ΔE _{u'v '} of the colorimetric coordinate error between the predicted colors obtained from the optimal matched color reproduction model and the matched colors obtained in the experiment is 0.00819. Accordingly, it can be seen that the error of the optimal color representation model is 34% less than the error 0.01249 of the von Kries color matching model and 51% less than the error 0.01689 of the Bartleson color matching model.

Table 9 and Fig. 11 show the average colorimetric coordinate errors obtained from the corresponding color reproduction models. As can be seen from FIG. 11, the average coordinate error magnitude is confirmed to be smaller in order of the corresponding color suggestion model, the Fairchild corresponding color suggestion model, the Bartleson corresponding color representation model, the Breneman corresponding color representation model, von Kries, and the CIECAM97s corresponding color representation model. It became.

In order to quantitatively evaluate and evaluate the colors reproduced in the corresponding color reproduction models in consideration of the luminance component, the average error was calculated using Equation 56 below based on the L ^* u ^* v ^* coordinate system. .

Here, L ₂ ^* is the luminance of the predicted color obtained from the corresponding color reproduction model, and L _a ^* is the luminance of the corresponding color obtained from Breneman's experiment. (u ₂ ^* , v ₂ ^* ) is the predicted color coordinate, and (u _a ^* , v _a ^* ) is the color coordinate of the corresponding color. N is the number of samples used in the experiment. The reason why the luminance value is multiplied by 1/4 is given by LE Demarsh and JE Pinney, "Studies of Some Colorimetric Problems in Color Television," J. lf SMPTE, vol. 79, pp. 338-342, April 1970, and so on, in the field of video display devices such as in television (TV) it is known that it is good to reduce the weight for luminance to 1/4 when calculating the color error.

Table 10 and FIG. 12 show average color resection errors obtained through Equation 55 in other corresponding color reproduction models that propose the Bartleson model calculated as the ratio of stimulus values. As can be seen from Table 10 and FIG. 12, the optimum color reproduction model is the best in color reproduction error, followed by Fairchild color reproduction model, von Kries color reproduction model, and CIECAM97s color reproduction model.

As verified through the above experiments, the optimal coherent color representation model has less colorimetric coordinate error than other corresponding color reproduction models in the entire luminance range, and the color reproduction error is higher than that of other corresponding color reproduction models even in the luminance consideration. great.

FIG. 13 is a flowchart illustrating the control procedure of steps S4 and S5 of FIG. 4 in greater detail.

White (W _L) of the ambient illumination light when the reference to Figure 13. If, white (W _L) of the ambient illumination light by the output of the yellow light sensor and cyan output voltage ratio between the color output of the light sensor (Ye / Cy) is determined, According to the white (W _D ) of the image display apparatus, Equations 1 and 2, the eye white (W _E ) of the eye obtained by the ambient illumination light and the composite image reproduced by the image display apparatus is obtained. The compliant white W _E is adapted by the composite image of the surrounding color and the corresponding color reproduced by the image display apparatus, but the white compliant eye W _E according to the illuminance of the illumination light according to Equations 1 and 2 as shown in FIG. ), When the illuminance is above 500 lx, the eyes are fully acclimatized to the white light. Therefore, when the illuminance of the ambient illumination light is 500 lx or more, it can be assumed that the eye-compatible white W _E becomes the white of the ambient illumination light.

Next, the correction processing unit 3 determines the parameter P of the optimally matched color representation model using Table 5 and Equation 52, and uses the input digital video data RoGoBo as Equation 57 below to calculate the XYZ stimulus value X ₁ Y _1. Convert to Z ₁ (S103 and S104)

Where x _Rd , x _Gd , x _Bd , y _Rd , y _Gd , y _Bd , z _Rd , z _Gd , and z _Bd are coordinate values for RGB, and K _Rd , K _Gd , and K _Bd are RGB channels Constant representing the gain of.

Subsequently, X ₁ Y ₁ Z ₁ is substituted into Equation 54, which is the conversion equation of the optimal color reproduction model, to calculate a correction XYZ stimulus value X ₂ Y ₂ Z ₂ to be reproduced in an environment adapted to illumination light (S105). The processing unit 3 generates the corrected digital video data RaGaBa to be supplied to the image display element through the inverse transformation of Equation 57 in order to reproduce the correction XYZ stimulus value X ₂ Y ₂ Z ₂ on the image display element 6. S106)

FIG. 15 shows an experimental result screen of an image in which a corresponding color is reproduced and an image in which an original image is reproduced using an optimal corresponding color representation model on a liquid crystal display. The size of the test image, the surrounding background, and the size of the viewing box used in the experiment of FIG. 15 are the same as those of FIG. 16. In this experiment, the test image was 10 ° viewing angle, the surrounding background of the liquid crystal display device was 30 ° viewing angle, and the viewing box corresponding to the viewing environment was 70 ° viewing angle. In addition, a haploscopic comparison method (G. Wyszecki and WS Stiles, Color Science, John Wiley & Sons, New York, 1982, pp. 117-451), which was a binocular independent simultaneous comparison evaluation method, was used. . 17 schematically illustrates this haploscopic method. In this experiment, the environment around the laboratory was in a dark state, and the influence of ambient light other than the illumination of the viewing box was excluded, and the LC151X01 model was used as the liquid crystal display device of the specimen. Evaluation of this experiment was carried out by subjective comparative evaluation using the D ₆₅ light source on the liquid crystal display device in which the original image is displayed and the background environment and illumination of the A light source on the liquid crystal display device in which the corresponding color is displayed.

Steps S11 and S12 of FIG. 4 will be described in detail. The absolute temperature of a complete radiator (black body) having the same chromaticity as any light source is defined as the color temperature of that light source, and the color temperature close to the trajectory of the black body is defined as the correlated color temperature.

The correction processing unit 3 adjusts the digital value of the data converted to the corresponding color in step S5 or S9 so that the relative color temperature of the gray level falls within the range of 6500K ± 100K based on D ₆₅ which is a standard light source of the image display device. Further, the correction processing unit 3 makes the luminance value of the gray level the same before and after the correlated color temperature correction. For example, if gray with an input digital value of R = 195, G = 195, and B = 195 has a luminance value of 111 cd / m ² , the correction processing unit 3 keeps the luminance value the same and is near 6500K. Adjust R = 204, G = 195 and B = 185 as much as possible. Therefore, for the corresponding color data values of R, G, and B that were the same before the correlation color temperature correction, the correction processing unit 3 increases the R input value based on the G input value after the correlation color temperature correction, while increasing the B input value. Decrease. Such correlation color temperature correction may be performed for discrete gray levels at predetermined intervals. In this case, the correlation color temperature is corrected by linear interpolation for gray levels that are not subjected to correlation color temperature correction.

Further, in order to maintain the maximum contrast ratio of the image display apparatus, the correction processing unit 3 does not perform color temperature correction on values around 255 where the R, G, and B digital values are maximum and near zero which is the minimum. The correction processing unit 3 does not correct dark areas having a large difference in correlation color temperature. This is because, due to the visual characteristics, the color recognition ability decreases when the brightness decreases, so that the color change is hardly recognized in the human visual system. The input digital value versus the correlated color temperature correction value for the gray level of the image display device stored in the correction processor 3 is shown in FIG. Such correlated color temperature correction data is composed of a lookup table and stored in a ROM (not shown) in the correction processor 3.

According to the experimental results of applying the correlation color temperature correction by the correction processing unit 3 to the liquid crystal display device, the chromaticity coordinates of the gray level which showed a considerable change according to the input digital value in the liquid crystal display device without the correlation color temperature correction as shown in FIG. Nearly constant after correlated color temperature correction.

In addition, according to the experiment results by applying the correlation color temperature correction by the correction processing unit 3 to the liquid crystal display device, the correlation color temperature of the gray level of the liquid crystal display device after the correlation color temperature correction as shown in FIG. 20 is close to 6500K similar to the cathode ray tube. Almost became constant.

In order to confirm color reproducibility with respect to the correlated color temperature according to an embodiment of the present invention, color coordinates before and after correlated color temperature correction using 18 colors of Macbeth color checker are shown in the CIE1976 u′v ′ coordinate system as shown in FIG. 21. In FIG. 21, the arrow shows the amount of variation between the existing color coordinates and the color coordinates corrected by the correlated color temperature correction value according to the present invention. As can be seen from FIG. 21, the error ΔE _uv ^{* according} to Equation 56, which is the chromaticity error equation of L ^* u ^* v ^* , was 15.39 before the correlation color temperature correction, whereas after the correlation color temperature correction by the correction processing unit 3 is 6.04. Significantly reduced. In fact, it was confirmed that the gray levels are more emphasized as shown in FIG. 22B after the correlation color temperature correction by the correction processing unit 3 with respect to the test image of FIG. 22A which has not been correlated color temperature correction.

23 and 24 illustrate an image display device according to another embodiment of the present invention. In FIG. 1, the A / D converter 2 and the correction processor 3 may be integrated and integrated into the one chip 231 as shown in FIG. 23. Further, the input signal processor 4 and the controller 5 together with the A / D converter 2 and the correction processor 3 may be integrated and integrated into the one chip 241 as shown in FIG. 24.

25 shows an active matrix type liquid crystal display device to which a color correction device of the image display device according to the present invention is applied.

Referring to FIG. 25, in the liquid crystal display according to the exemplary embodiment, m × n liquid crystal cells Clc are arranged in a matrix type, and m data lines D1 to Dm and n gate lines ( A liquid crystal display panel 255 having a thin film transistor (hereinafter referred to as "TFT") formed at an intersection thereof, and a backlight unit for irradiating light to the liquid crystal display panel 255. A data driver circuit 253 for supplying data to the data lines D1 to Dm of the liquid crystal display panel 255, and a gate for supplying scan pulses to the gate lines G1 to Gn. A timing controller 252 for controlling the driving circuit 254, the data driving circuit 253, and the gate driving circuit 254, and an interface circuit 251 connected between the system 259 and the timing controller 252. And a DC-DC converter D for generating driving voltages of the liquid crystal display panel 255. C to DC Convertor (hereinafter referred to as DC-DC converter) 258, and an inverter 257 for driving the backlight unit 256.

In addition, the liquid crystal display according to the embodiment of the present invention determines the ambient white light by the yellow light sensor (261a) and the cyan light sensor (261b), and the compliance white point by the ambient light, and the corresponding color correction and correlation color temperature correction A correction processor 260 for processing is further provided.

In the liquid crystal display panel 255, liquid crystal molecules are injected between two glass substrates. The data lines D1 to Dm and the gate lines G1 to Gn formed on the lower glass substrate of the liquid crystal display panel 255 are perpendicular to each other. The TFTs formed at the intersections of the data lines D1 to Dm and the gate lines G1 to Gn liquid crystal the data on the data lines D1 to Dn in response to the scan pulses from the gate lines G1 to Gn. It is supplied to the cell Clc. For this purpose, the gate electrodes of the TFTs are connected to the gate lines G1 to Gn, and the source electrodes are connected to the data lines D1 to Dm. The drain electrode of the TFT is connected to the pixel electrode of the liquid crystal cell Clc. A black matrix, a color filter, and a common electrode (not shown) are formed on the upper glass substrate of the liquid crystal display panel 255. On the upper glass substrate and the lower glass substrate of the liquid crystal display panel 255, a polarizing plate having an optical axis orthogonal to each other is attached, and an alignment layer for setting the pretilt angle of the liquid crystal is formed on the inner side of the liquid crystal display panel 255. In addition, a storage capacitor Cst is formed in each of the liquid crystal cells Clc of the liquid crystal display panel 255. The storage capacitor Cst is formed between the pixel electrode of the liquid crystal cell Clc and the front gate line, or is formed between the pixel electrode of the liquid crystal cell Clc and the common electrode line (not shown) to change the voltage of the liquid crystal cell Clc. It keeps constant.

The graphics processing circuit of the system 259 converts analog video data into digital video data and adjusts the resolution and color temperature of the digital video data RoGoBo. The digital video data RoGoBo and the vertical / horizontal synchronization signal and the clock signal output from the system 250 are supplied to the timing controller 252 through the interface circuit 251.

The interface circuit 251 converts the digital video data (RoGoBo) to TTL or CMOS level and transmits them in parallel, or parallelly compresses and transmits the digital video data (RoGoBo) to serial data. It is implemented by Low Voltage Differential Signaling (LVDS). The frequency and voltage of the digital video data RoGoBo supplied to the timing controller 252 and the data driving circuit 253 may be lowered by the interface circuit 251, and signal wiring for transmitting the digital video data RoGoBo is performed. The number of is reduced.

The timing controller 252 is a gate control signal (GDC) and data for controlling the gate driving circuit 254 using the vertical / horizontal synchronization signal and the clock signal supplied from the system 259 via the interface circuit 251. A data control signal DDC for controlling the driving circuit 253 is generated. The gate control signal GDC includes a gate start pulse GSP, a gate shift clock GSC, a gate output enable GOE, and the like. The data control signal (DDC) includes a source start pulse (GSP), a source shift clock (SSC), a source output signal (SOC), a polarity signal (POL), and the like. do. The timing controller 252 samples the digital video data RoGoBo input from the system 259 via the interface circuit 251, rearranges it, supplies it to the correction processor 260, and corrects the correction by the correction processor 260. The data RaGaBa is supplied to the data driver 253.

The data driver circuit 253 converts the corrected digital video data RaGaBa into an analog gamma compensation voltage corresponding to the gray scale value in response to the data control signal DDC from the timing controller 252 and converts the analog gamma compensation voltage into data. The voltage is supplied to the data lines D1 to Dm with voltage. The analog gamma compensation voltage is generated by a gamma circuit for dividing the VDD voltage generated from the DC-DC converter 258 into a voltage equal to the number of gray levels of the digital video data.

The gate driving circuit 254 sequentially supplies the scan pulse Scp to the gate lines G1 to Gn in response to the gate control signal GDC from the timing controller 252 to supply data. 255) select the horizontal line.

The DC-DC converter 258 uses the VCC voltage supplied from the power supply of the system 259 to obtain a high potential common voltage, VDD voltage, Vcom voltage of 2.5 to 3.3V, Vgh voltage of 20 to 25V, and Vgl of -5V. Generate voltage. The Vgh voltage is supplied to the gate driving circuit 254 as the high logic voltage of the scan pulse set above the threshold voltage of the TFT and the Vgl voltage is the low logic voltage of the set scan pulse lower than the threshold voltage of the TFT to the gate driving circuit 254. Supplied.

The inverter 257 converts the inverter DC input voltage Vinv supplied from the power supply of the system 259 into an AC voltage and boosts the AC voltage to supply the tube current to the lamps of the backlight unit 256.

The backlight unit 256 converts the line light source generated by the light emission of the lamps into a surface light source and irradiates the liquid crystal display panel 255.

The yellow light sensor 261a and the cyan light sensor 261b detect yellow light and cyan light of ambient illumination light that affect the display image of the liquid crystal display panel 255. The analog voltages output from the yellow light sensor 261a and the cyan light sensor 261b are converted into digital data by the A / D converter 262 and then supplied to the correction processor 260.

The correction processor 260 corrects the corresponding color and the correlated color temperature with respect to the input digital video data RiGiBi according to a series of control procedures of FIGS. 4 and 13. That is, the correction processing unit 260 amplifies the voltage from the A / D converter 262 and adjusts the output voltage ratio Ye / Cy between the output of the yellow light sensor 161a and the output of the cyan light sensor 261b. The color voltage of the ambient illumination light is determined by comparing the output voltage ratio Ye / Cy with the pre-stored ambient illumination light source to voltage ratio data. The correction processing unit 260 then calculates the compliance white point of the eye with respect to the determined ambient illumination light and calculates the corresponding color from the compliance white point. The correction processing unit 3 also corrects the correlated color temperature with respect to the corresponding color correction data. The output voltage ratio (Ye / Cy) calculation, the compliance white point calculation, the corresponding color calculation, and the correlation color correction of the light detecting unit 1 are processed in the automatic mode or the manual mode as shown in FIG. In the automatic mode, the output voltage ratio (Ye / Cy) calculation, the compliance white point calculation, and the corresponding color calculation of the light sensing unit 1 are automatically performed by a preset algorithm, and optionally, the correlation color correction for the corresponding color data is automatically performed. Is carried out. In manual mode, the corresponding color calculation is processed according to a user command input through a user interface such as an on-screen display or a remote controller, and optionally, a correlated color temperature correction is processed.

The A / D converter 262, the correction processor 260, the interface circuit 251, and the timing controller 252 may be integrated into one chip as illustrated in FIGS. 23 and 24.

On the other hand, the color correction method and apparatus of the image display device according to the present invention is not only a transmissive liquid crystal display device shown in Figure 25, but also a reflective liquid crystal display device, a field emission display (FED), a plasma display panel ( The present invention can also be applied to other flat panel display devices such as plasma display panels (PDPs) and electroluminescent devices (EL).

As described above, the color correction method and apparatus of the image display device according to the present invention calculate the gains of L-cell cells corresponding to red and M-cell cells corresponding to green linearly according to ambient chromaticity and luminance, and correspond to blue. The gain of S-cells is calculated non-linearly, and the corresponding color is calculated using an optimal corresponding color model that optimizes the proportional coefficient corresponding to blue, and the corresponding color is reproduced. As a result, the color correction method and apparatus of the image display apparatus according to the present invention reproduces the corresponding color which looks the same as the color of the original subject in the standard illumination light source in the actual use environment by using the color adaptation phenomenon of the human visual system and the corresponding color principle. As a result, the display image that varies depending on the ambient light or the surrounding environment can be made identical to the actual image. Furthermore, the color correction method and apparatus of the image display device according to the present invention further improve the display quality of the image display device by correcting the change in the correlated color temperature according to the change in the input value of the gray level with respect to the corresponding color without deteriorating the luminance and contrast ratio. Can be high.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1 is a block diagram schematically illustrating an image display apparatus according to an exemplary embodiment of the present invention.

2 is a graph showing an output voltage ratio Ye / Cy between an output of a yellow light sensor and an output of a cyan light sensor according to illuminance of representative light sources.

3 is a diagram illustrating an output voltage ratio with respect to an ambient illumination light source.

4 is a flowchart showing step by step a control procedure of a color correction method of an image display device according to an exemplary embodiment of the present invention.

FIG. 5 is a diagram schematically illustrating an environment of a surrounding city when observing an image display device.

6 is a diagram illustrating an experiment on the compliance white shift of the eye.

7 is a graph showing the compliance white of the eye according to the ambient illumination light illumination.

FIG. 8A is a graph showing the conforming white coordinates when the reference white light source of the image display device is D ₆₅ and the illumination light is an incandescent lamp.

8B is a graph showing compliant white coordinates when the reference white light source of the image display device is 9300K + 27MDCP and the illumination light is fluorescent.

9 is a graph showing the value of the power P according to the ambient luminance in the optimum corresponding color model.

FIG. 10 is a diagram illustrating a corresponding color reproduced by an optimum corresponding color model in the u′v ′ coordinate system. FIG.

FIG. 11 is a graph illustrating a comparison of average colorimetric coordinate errors obtained in respective corresponding color reproduction models. FIG.

FIG. 12 is a graph illustrating a comparison of average color lag errors obtained from corresponding color reproduction models in consideration of luminance. FIG.

FIG. 13 is a flowchart illustrating the control procedure of steps S4 and S5 of FIG. 4 in greater detail.

FIG. 14 is a graph showing an acclimatized white point (W _D = D ₆₅ , W _L = 6500 K) of an eye according to illuminance of illumination light.

FIG. 15 is an experimental result screen simultaneously showing an image (W _L = A) of reproducing a corresponding color and an image of reproducing an original image (W _L = D ₆₅ ) using an optimal corresponding color representation model on a liquid crystal display.

FIG. 16 is a diagram illustrating the size of the test image, the surrounding background, and the size of the viewing box used in the experiment of FIG. 15.

17 is a view schematically showing a hafloscopic method.

18 is a graph showing a correlated color temperature value with respect to an input digital value.

FIG. 19 is a diagram illustrating an xy coordinate system representing a chromaticity coordinate correction result of a gray level after correlation color temperature correction according to an exemplary embodiment of the present invention.

20 is a graph comparing a liquid crystal display device and a cathode ray tube after correlated color temperature correction according to an embodiment of the present invention.

FIG. 21 is a diagram illustrating a correlation color temperature correction effect for various colors in a u′v ′ coordinate system.

22A is a diagram showing a black and white test image before correction selected in an experiment for verifying a correlation color temperature correction effect.

22B is a diagram showing after the correlation color temperature correction for the test image of FIG. 22A.

23 and 24 illustrate an image display apparatus according to another embodiment of the present invention.

25 is a diagram illustrating an active matrix type liquid crystal display device to which a color correction device of the image display device according to the present invention is applied.

<Description of Symbols for Main Parts of Drawings>

1: light sensing unit 2, 262: analog / digital converting unit

3, 261: correction processing unit 4: input signal processing unit

5 controller 6 image display device

251: interface circuit 252: timing controller

253: data driving circuit 254: gate driving circuit

255 liquid crystal display panel 256 backlight unit

257 inverter 258 DC-DC converter

259 system 261a yellow light sensor

261b: Cyan Light Sensor

Claims (76)

Sensing ambient illumination light; Determining a compliant white point of the eye adapted by the ambient illumination light; Correcting the input data with a corresponding color such that the display image reproduced in the image display apparatus looks the same as the original image based on the compliant white; And reproducing the corresponding color data on the image display apparatus. The method of claim 1, Sensing the ambient illumination light, Sensing yellow light of the ambient illumination light and outputting a yellow detection voltage corresponding thereto; Sensing cyan light of the ambient illumination light and outputting a cyan light detection voltage corresponding thereto; Calculating a ratio of the yellow sense voltage to the cyan sense voltage and comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data; And determining the ambient illumination light according to the comparison result. The method of claim 1, Determining the compliant white point, Using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the following conforming white point W _E (u _E , v _E ) to determine the color correction method of the video display device. ------------- Formula (1) ------------- Formula (2) Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037 The method of claim 1, Correcting the input data by the corresponding color, Calculating an XYZ stimulus of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; The step of using the L _a M _a S _a predetermined proportional coefficient and the input data of the magnetic pole teeth of the magnetic pole teeth XYZ generate corresponding color data in the XYZ stimulus and; And converting corresponding color data of the XYZ stimulus values into RGB data. The method of claim 4, wherein Calculating the stimulus value after the color adaptation, And a stimulus value after the color adaptation using equations (3) to (5) below. L _a = k _L L ------------- Formula (3) M _a = k _M M ------------- Formula (4) S _a = (k _S ) ^P S ------------- Formula (5) Where L, M and S are eye stimulus values for the original image, k _L , k _M , k _S are proportional coefficients between the stimulus values of the eye after the original image and the color adaptation, and P is the luminance change of the original image. Is a factor that ensures that there is a minimum error between different illumination light environments. The method of claim 5, The proportional coefficients k _L , k _M , k _S are as shown in Equations 6 to 8 below. k _L = L _max2 / L _max1 ------------- Equation (6) k _M = M _max2 / M _max1 ------------- Equation (7) k _S = S _max2 / S _max1 ------------- Equation (8) Where L _max1 , M _max1 , S _max1 is an eye stimulus obtained from the white or the maximum stimulus of the original image, and L _max2 , M _max2 , S _max2 is an eye irritation value obtained at an acclimatized white point of the eye adapted by the ambient illumination light and the image display apparatus. The method of claim 5, The coefficient P is a color correction method of an image display device, characterized by the following equations (9) and (10). P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )   ------------- Formula (9) P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )   ------------- Formula (10) Where Y is luminance. The method of claim 4, wherein And the relationship between the L _a M _a S _a stimulus value and the XYZ stimulus value is expressed by Equation 11 below. max1 max1, max2 W _E   ------------- Formula (11) Where X _max1 , Y _max1 , Z _max1 is the XYZ stimulus obtained from the white or maximum stimulus of the original image, L _max1 , M _max1 , S _max1 is the LMS stimulus obtained from the white or maximum stimulus of the original image, L _max2 , M _max2 , S _max2 is the stimulus value obtained at the compliance white point of the eye, which is adapted by the ambient illumination light and the image display device, and W _E is the compliance white of the eye. The method of claim 4, wherein And corresponding color data of the XYZ stimulus values are calculated by Equation 12 below. ------------- Formula (12) Here, X ₁ , Y ₁ , and Z ₁ are eye irritation values for the original image, and X ₂ , Y ₂ , and Z ₂ are eye irritation values for the corresponding color. The method of claim 1, The image display apparatus is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an electroluminescent element (EL). Sensing ambient illumination light; Determining a compliant white point of the eye adapted by the ambient illumination light; Correcting the input data with a corresponding color such that the display image reproduced in the image display apparatus looks the same as the original image based on the compliant white; Correcting a correlated color temperature with respect to the corresponding color data; And reproducing the data on which the corresponding color and the correlated color temperature are corrected on the image display apparatus. The method of claim 11, Sensing the ambient illumination light, Sensing yellow light of the ambient illumination light and outputting a yellow detection voltage corresponding thereto; Sensing cyan light of the ambient illumination light and outputting a cyan light detection voltage corresponding thereto; Calculating a ratio of the yellow sense voltage to the cyan sense voltage and comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data; And determining the ambient illumination light according to the comparison result. The method of claim 11, Determining the compliant white point, Using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the following conforming white point W _E (u _E , v _E ) to determine the color correction method of the video display device. ------------- Formula (1) ------------- Formula (2) Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037 The method of claim 11, Correcting the input data by the corresponding color, Calculating an XYZ stimulus of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; The step of using the L _a M _a S _a predetermined proportional coefficient and the input data of the magnetic pole teeth of the magnetic pole teeth XYZ generate corresponding color data in the XYZ stimulus and; And converting corresponding color data of the XYZ stimulus values into RGB data. The method of claim 14, Calculating the stimulus value after the color adaptation, And a stimulus value after the color adaptation using equations (3) to (5) below. L _a = k _L L ------------- Formula (3) M _a = k _M M ------------- Formula (4) S _a = (k _S ) ^P S ------------- Formula (5) Where L, M, and S are eye stimulus values for the input data, k _L , k _M , k _S are proportional coefficients between the stimulus values of the eye after the original image and the color adaptation, and P is the brightness change of the original image. Is a factor that ensures that there is a minimum error between different illumination light environments. The method of claim 15, The proportional coefficients k _L , k _M , k _S are as shown in Equations 6 to 8 below. k _L = L _max2 / L _max1 ------------- Equation (6) k _M = M _max2 / M _max1 ------------- Equation (7) k _S = S _max2 / S _max1 ------------- Equation (8) Where L _max1 , M _max1 , S _max1 is an eye stimulus obtained from the white or the maximum stimulus of the original image, and L _max2 , M _max2 , S _max2 is an eye irritation value obtained at an acclimatized white point of the eye adapted by the ambient illumination light and the image display apparatus. The method of claim 15, The coefficient P is a color correction method of an image display device, characterized by the following equations (9) and (10). P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )   ------------- Formula (9) P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )   ------------- Formula (10) Where Y is luminance. The method of claim 14, And the relationship between the L _a M _a S _a stimulus value and the XYZ stimulus value is expressed by Equation 11 below. max1 max1, max2 W _E   ------------- Formula (11) Where X _max1 , Y _max1 , Z _max1 is the XYZ stimulus obtained from the white or maximum stimulus of the original image, L _max1 , M _max1 , S _max1 is the LMS stimulus obtained from the white or maximum stimulus of the original image, L _max2 , M _max2 , S _max2 is the stimulus value obtained at the compliance white point of the eye, which is adapted by the ambient illumination light and the image display device, and W _E is the compliance white of the eye. The method of claim 17, And corresponding color data of the XYZ stimulus values are calculated by Equation 12 below. ------------- Formula (12) Here, X ₁ , Y ₁ , and Z ₁ are eye irritation values for the original image, and X ₂ , Y ₂ , and Z ₂ are eye irritation values for the corresponding color data. The method of claim 11, Correcting the correlated color temperature, And adjusting the correlated color temperature of the corresponding color data within the range of 6500K ± 100K. The method of claim 11, Correcting the correlated color temperature, And increasing the value of the red data and decreasing the value of the blue data in the corresponding color data. The method of claim 11, Correcting the correlated color temperature, And correcting the correlated color temperature by linear interpolation. The method of claim 11, Correcting the correlated color temperature, And a correlated color temperature is not corrected for the corresponding color data corresponding to the maximum value and the minimum value of the input data. The method of claim 11, The image display apparatus is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an electroluminescent element (EL). Checking a current operation mode; Sensing ambient illumination light; If the operation mode is the automatic mode, the display apparatus reproduces the display image reproduced by the image display apparatus by using a preset corresponding color reproduction model by determining the acclimatized white point of the eye adapted by the ambient illumination light. Generating 1 corresponding color data; If the operation mode is the manual mode, the display image reproduced by the image display apparatus is determined by determining the acclimatized white point of the eye conformed by the ambient illumination light and using the corresponding color reproduction model selected by the user among the corresponding color reproduction models. Generating second corresponding color data to look the same as the image; Selectively correcting a correlated color temperature with respect to said first and second corresponding color data; And reproducing any one of the first and second corresponding color data and the data whose correlated color temperature is corrected on the image display apparatus. The method of claim 25, Sensing the ambient illumination light, Sensing yellow light of the ambient illumination light and outputting a yellow detection voltage corresponding thereto; Sensing cyan light of the ambient illumination light and outputting a cyan light detection voltage corresponding thereto; Calculating a ratio of the yellow sense voltage to the cyan sense voltage and comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data; And determining the ambient illumination light according to the comparison result. The method of claim 25, Determining the compliant white point, Using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the following conforming white point W _E (u _E , v _E ) to determine the color correction method of the video display device. ------------- Formula (1) ------------- Formula (2) Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037 The method of claim 25, The generating of the first corresponding color data may include: Calculating an XYZ stimulus of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; The step of using the L _a M _a S _a predetermined proportional coefficient and the input data of the magnetic pole teeth of the magnetic pole teeth XYZ generate corresponding color data in the XYZ stimulus and; And converting corresponding color data of the XYZ stimulus values into RGB data. The method of claim 28, Calculating the stimulus value after the color adaptation, And a stimulus value after the color adaptation using equations (3) to (5) below. L _a = k _L L ------------- Formula (3) M _a = k _M M ------------- Formula (4) S _a = (k _S ) ^P S ------------- Formula (5) Where L, M and S are eye stimulus values for the original image, k _L , k _M , k _S are proportional coefficients between the stimulus values of the eye after the original image and the color adaptation, and P is the luminance change of the original image. Is a factor that ensures that there is a minimum error between different illumination light environments. The method of claim 29, The proportional coefficients k _L , k _M , k _S are as shown in Equations 6 to 8 below. k _L = L _max2 / L _max1 ------------- Equation (6) k _M = M _max2 / M _max1 ------------- Equation (7) k _S = S _max2 / S _max1 ------------- Equation (8) Where L _max1 , M _max1 , S _max1 is an eye stimulus obtained from the white or the maximum stimulus of the original image, and L _max2 , M _max2 , S _max2 is an eye irritation value obtained at an acclimatized white point of the eye adapted by the ambient illumination light and the image display apparatus. The method of claim 29, The coefficient P is a color correction method of an image display device, characterized by the following equations (9) and (10). P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )   ------------- Formula (9) P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )   ------------- Formula (10) Where Y is luminance. The method of claim 28, And the relationship between the L _a M _a S _a stimulus value and the XYZ stimulus value is expressed by Equation 11 below. max1 max1, max2 W _E   ------------- Formula (11) Where X _max1 , Y _max1 , Z _max1 is the XYZ stimulus obtained from the white or maximum stimulus of the original image, L _max1 , M _max1 , S _max1 is the LMS stimulus obtained from the white or maximum stimulus of the original image, L _max2 , M _max2 , S _max2 is the stimulus value obtained at the compliance white point of the eye, which is adapted by the ambient illumination light and the image display device, and W _E is the compliance white of the eye. The method of claim 31, wherein And corresponding color data of the XYZ stimulus values are calculated by Equation 12 below. ------------- Formula (12) Here, X ₁ , Y ₁ , and Z ₁ are eye irritation values for the original image, and X ₂ , Y ₂ , and Z ₂ are eye irritation values for the corresponding color data. The method of claim 33, wherein Many of the corresponding color reproduction models, An image comprising the corresponding color reproduction model, von Kries corresponding color reproduction model, Breneman corresponding color reproduction model, Bartleson corresponding color reproduction model, Fairchild corresponding color reproduction model, and CIECAM97s corresponding color reproduction model defined by Equation 12 Color correction method of display device. The method of claim 25, Correcting the correlated color temperature, And adjusting the correlated color temperature of the corresponding color data within the range of 6500K ± 100K. The method of claim 25, Correcting the correlated color temperature, And increasing the value of the red data and decreasing the value of the blue data in the corresponding color data. The method of claim 25, Correcting the correlated color temperature, And correcting the correlated color temperature by linear interpolation. The method of claim 25, Correcting the correlated color temperature, And a correlated color temperature is not corrected for the corresponding color data corresponding to the maximum value and the minimum value of the input data. The method of claim 25, The image display apparatus is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an electroluminescent element (EL). A detector for detecting ambient illumination light; A correction processor configured to determine a conforming white point of the eye adapted by the ambient illumination light and to correct the input data with a corresponding color such that the display image reproduced by the image display apparatus looks the same as the original image based on the conformal white; And a display control unit for reproducing the corresponding color data on the image display device. The method of claim 40, The detection unit, An optical sensor for detecting yellow light of the ambient illumination light, outputting a yellow detection voltage corresponding thereto, and detecting cyan light of the ambient illumination light and outputting a cyan detection voltage corresponding thereto; And an analog / digital converter configured to convert each of the yellow detection voltage and the cyan detection voltage into digital data. 42. The method of claim 41 wherein The correction processing unit, Calculating a ratio of the yellow detection voltage and the cyan detection voltage converted into the digital data, comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data, and determining the ambient illumination light according to the comparison result. Color compensator of video display device. The method of claim 40, The correction processing unit, Using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the following conforming white point W _E (u _E , v _E ) to determine the color correction apparatus of the video display device. ------------- Formula (1) ------------- Formula (2) Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037 The method of claim 40, The correction processing unit, Calculate an XYZ stimulus of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; Wherein by using a predetermined proportional coefficient and the input data of the XYZ stimulus for _a L _a M _a magnetic pole S generates a corresponding color data in the XYZ stimulus; And a corresponding color data of the XYZ stimulus values into RGB data. The method of claim 44, The correction processing unit, Color correction apparatus of the image display device, characterized in that to calculate the stimulus value after the color adaptation using the following equations (3) to (5). L _a = k _L L ------------- Formula (3) M _a = k _M M ------------- Formula (4) S _a = (k _S ) ^P S ------------- Formula (5) Where L, M and S are eye stimulus values for the original image, k _L , k _M , k _S are proportional coefficients between the stimulus values of the eye after the original image and the color adaptation, and P is the luminance change of the original image. Is a factor that ensures that there is a minimum error between different illumination light environments. The method of claim 45, And the proportional coefficients k _L , k _M , and k _S are as shown in Equations 6 to 8 below. k _L = L _max2 / L _max1 ------------- Equation (6) k _M = M _max2 / M _max1 ------------- Equation (7) k _S = S _max2 / S _max1 ------------- Equation (8) Where L _max1 , M _max1 , S _max1 is an eye stimulus obtained from the white or the maximum stimulus of the original image, and L _max2 , M _max2 , S _max2 is an eye irritation value obtained at an acclimatized white point of the eye adapted by the ambient illumination light and the image display apparatus. The method of claim 45, The coefficient P is a color compensating device of an image display device, characterized in that the following equations (9) and (10). P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )   ------------- Formula (9) P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )   ------------- Formula (10) Where Y is luminance. The method of claim 44, And a relationship between the L _a M _a S _a stimulus value and the XYZ stimulus value is expressed by Equation 11 below. max1 max1, max2 W _E   ------------- Formula (11) Where X _max1 , Y _max1 , Z _max1 is the XYZ stimulus obtained from the white or maximum stimulus of the original image, L _max1 , M _max1 , S _max1 is the LMS stimulus obtained from the white or maximum stimulus of the original image, L _max2 , M _max2 , S _max2 is the stimulus value obtained at the compliance white point of the eye, which is adapted by the ambient illumination light and the image display device, and W _E is the compliance white of the eye. The method of claim 47, And corresponding color data of the XYZ stimulus values is calculated by Equation 12 below. ------------- Formula (12) Here, X ₁ , Y ₁ , and Z ₁ are eye irritation values for the original image, and X ₂ , Y ₂ , and Z ₂ are eye irritation values for the corresponding color. The method of claim 40, And the image display device is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescent device (EL). A detector for detecting ambient illumination light; Determining an acclimatized white point of the eye adapted by the ambient illumination light, and correcting the input data with a corresponding color such that the display image reproduced on the image display apparatus looks the same as the original image based on the compliance white; A correction processing unit for correcting a correlated color temperature with respect to the correlation; And a display control unit which reproduces the data of which the corresponding color and the correlated color temperature are corrected on the image display device. The method of claim 51, wherein The detection unit, An optical sensor for detecting yellow light of the ambient illumination light, outputting a yellow detection voltage corresponding thereto, and detecting cyan light of the ambient illumination light and outputting a cyan detection voltage corresponding thereto; And an analog / digital converter configured to convert each of the yellow detection voltage and the cyan detection voltage into digital data. The method of claim 52, wherein The correction processing unit, Calculating a ratio of the yellow detection voltage and the cyan detection voltage converted into the digital data, comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data, and determining the ambient illumination light according to the comparison result. Color compensator of video display device. The method of claim 51, wherein The correction processing unit, Using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the following conforming white point W _E (u _E , v _E ) to determine the color correction apparatus of the video display device. ------------- Formula (1) ------------- Formula (2) Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037 The method of claim 51, wherein The correction processing unit, Calculate an XYZ stimulus of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; Wherein by using a predetermined proportional coefficient and the input data of the XYZ stimulus for _a L _a M _a magnetic pole S generates a corresponding color data in the XYZ stimulus; And a corresponding color data of the XYZ stimulus values into RGB data. The method of claim 51, wherein The correction processing unit, And a correlated color temperature of the corresponding color data within a range of 6500K ± 100K. The method of claim 51, wherein The correction processing unit, And increasing the value of the red data and decreasing the value of the blue data in the corresponding color data. The method of claim 51, wherein The correction processing unit, And correcting the correlated color temperature by linear interpolation. The method of claim 51, wherein The correction processing unit, And the correlated color temperature is not corrected for the corresponding color data corresponding to the maximum and minimum values of the input data. The method of claim 51, wherein The image display device is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an electroluminescent device (EL). A detector for detecting ambient illumination light; If the current operation mode is checked and the operation mode is the automatic mode, the display image reproduced by the image display apparatus is determined by determining the acclimatized white point of the eye conformed by the ambient illumination light and using one preset color reproduction model. A first correction processor for generating first corresponding color data to make the image look the same as the image; If the operation mode is the manual mode, the display image reproduced by the image display apparatus is determined by determining the acclimatized white point of the eye conformed by the ambient illumination light and using the corresponding color reproduction model selected by the user among the corresponding color reproduction models. A second correction processor for displaying second corresponding color data to make the image look the same as the image; A third correction processor for selectively correcting a correlated color temperature with respect to the first and second corresponding color data; And a display control unit which reproduces any one of the first and second corresponding color data and the data whose correlated color temperature is corrected on the image display device. 62. The method of claim 61, The detection unit, An optical sensor for detecting yellow light of the ambient illumination light, outputting a yellow detection voltage corresponding thereto, and detecting cyan light of the ambient illumination light and outputting a cyan detection voltage corresponding thereto; And an analog / digital converter configured to convert each of the yellow detection voltage and the cyan detection voltage into digital data. The method of claim 62, The first and second correction processing unit, Calculating a ratio of the yellow detection voltage and the cyan detection voltage converted into the digital data, comparing the voltage ratio with pre-stored ambient illumination light source to voltage ratio data, and determining the ambient illumination light according to the comparison result. Color compensator of video display device. 62. The method of claim 61, The first correction processing unit, Using the white coordinates W _L (u _L , v _L ) of the ambient illumination light, the white coordinates W _D (u _D , v _D ) of the image display device, and the following conforming white point W _E (u _E , v _E ) to determine the color correction apparatus of the video display device. ------------- Formula (1) ------------- Formula (2) Where Δu = u _L -u _D , Δv = v _L -v _D , a = 0.571, b = -0.445, c = 0.037 62. The method of claim 61, The first correction processing unit, Calculate an XYZ stimulus of the input data; Calculating the stimulus value L _a corresponding to the red color after the linear color adaptation and the stimulus value M _a corresponding to the green color after the color adaptation, and non-linearly calculating the stimulus value S _a corresponding to the blue color after the color adaptation; Wherein by using a predetermined proportional coefficient and the input data of the XYZ stimulus for _a L _a M _a magnetic pole S generates a corresponding color data in the XYZ stimulus; And a corresponding color data of the XYZ stimulus values into RGB data. 66. The method of claim 65, The first correction processing unit, Color correction apparatus of the image display device, characterized in that to calculate the stimulus value after the color adaptation using the following equations (3) to (5). L _a = k _L L ------------- Formula (3) M _a = k _M M ------------- Formula (4) S _a = (k _S ) ^P S ------------- Formula (5) Where L, M and S are eye stimulus values for the original image, k _L , k _M , k _S are proportional coefficients between the stimulus values of the eye after the original image and the color adaptation, and P is the luminance change of the original image. Is a factor that ensures that there is a minimum error between different illumination light environments. The method of claim 66, wherein And the proportional coefficients k _L , k _M , and k _S are as shown in Equations 6 to 8 below. k _L = L _max2 / L _max1 ------------- Equation (6) k _M = M _max2 / M _max1 ------------- Equation (7) k _S = S _max2 / S _max1 ------------- Equation (8) Where L _max1 , M _max1 , S _max1 is an eye stimulus obtained from the white or the maximum stimulus of the original image, and L _max2 , M _max2 , S _max2 is an eye irritation value obtained at an acclimatized white point of the eye adapted by the ambient illumination light and the image display apparatus. The method of claim 66, wherein The coefficient P is a color compensating device of an image display device, characterized in that the following equations (9) and (10). P = 0.194052 × (3.731458-exp (-0.035637 × Y)), (Y≤350 cd / m ² )   ------------- Formula (9) P = 0.470266 × 0.999998 ^Y × Y ^0.073806 , (Y≥350 cd / m ² )   ------------- Formula (10) Where Y is luminance. The method of claim 68, wherein And a relationship between the L _a M _a S _a stimulus value and the XYZ stimulus value is expressed by Equation 11 below. max1 max1, max2 W _E   ------------- Formula (11) Where X _max1 , Y _max1 , Z _max1 is the XYZ stimulus obtained from the white or maximum stimulus of the original image, L _max1 , M _max1 , S _max1 is the LMS stimulus obtained from the white or maximum stimulus of the original image, L _max2 , M _max2 , S _max2 is the stimulus value obtained at the compliance white point of the eye, which is adapted by the ambient illumination light and the image display device, and W _E is the compliance white of the eye. The method of claim 68, wherein And corresponding color data of the XYZ stimulus values is calculated by Equation 12 below. ------------- Formula (12) Here, X ₁ , Y ₁ , and Z ₁ are eye irritation values for the original image, and X ₂ , Y ₂ , and Z ₂ are eye irritation values for the corresponding color data. The method of claim 70, Many of the corresponding color reproduction models, An image comprising a corresponding color reproduction model, von Kries corresponding color reproduction model, Breneman corresponding color reproduction model, Bartleson corresponding color reproduction model, Fairchild corresponding color reproduction model, and CIECAM97s corresponding color reproduction model defined by Equation 12 Display color correction device. 62. The method of claim 61, The third correction processing unit, And a correlated color temperature of the corresponding color data within a range of 6500K ± 100K. 62. The method of claim 61, The third correction processing unit, And increasing the value of the red data and decreasing the value of the blue data in the corresponding color data. 62. The method of claim 61, The third correction processing unit, And correcting the correlated color temperature by linear interpolation. 62. The method of claim 61, The third correction processing unit, And the correlated color temperature is not corrected for the corresponding color data corresponding to the maximum and minimum values of the input data. 62. The method of claim 61, And the image display device is any one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescent device (EL).