Detailed Description
The following is a description of embodiments of the present invention with reference to specific embodiments, and those skilled in the art will understand the advantages and effects of the present invention from the disclosure of the present specification. The invention is capable of other and different embodiments and its several details are capable of modification and various other changes, which can be made in various details within the specification and without departing from the spirit and scope of the invention. The drawings of the present invention are for illustrative purposes only and are not intended to be drawn to scale. The following embodiments will further explain the related art of the present invention in detail, but the disclosure is not intended to limit the scope of the present invention.
It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are used primarily to distinguish one element from another element or from one signal to another signal. In addition, the term "or" as used herein should be taken to include any one or combination of more of the associated listed items as the case may be.
The disclosure provides a panel color temperature matching correction method and a system for implementing the method, which are applied to a color correction method of a flat panel display (such as an LED backlight), different from a method of performing color adjustment only on a central part of the display (including the backlight and a display panel) when the display is delivered from a factory in the prior art, one embodiment of the proposed method adopts three color stimulus values of colors as target parameters for adjustment, and the adjustment of the rest parts is considered besides the adjustment of the original central part or partial area. The method is mainly characterized in that a two-dimensional color analyzer (2D color analyzer, called as a second color analyzer) is additionally arranged outside a conventional color analyzer (called as a first color analyzer) to perform auxiliary measurement so as to measure the characteristics of the complete display area of the display, thereby correcting the problem that the traditional first color analyzer can only measure partial areas of a display panel and causes different feelings of human eyes on different parts of the whole display.
The two-dimensional color analyzer (second color analyzer) can measure the influence of the visible angle of different areas and the color and brightness mixture among different areas on the display, so that the color information of the display obtained by the two-dimensional color analyzer is more similar to the perception of human eyes, and the problem caused by that the original color analyzer (first color analyzer) can only measure partial areas is corrected. However, since the two-dimensional color analyzer takes longer time to measure the panel area of the whole display than the conventional color analyzer, a panel color temperature matching correction method is proposed, which comprises the measurement of the second color analyzer and the first color analyzer, and the defect compensation for the measurement area and the measurement time.
The system for implementing the panel color temperature matching calibration method is provided with a first color analyzer and a second color analyzer, wherein the first color analyzer is used for obtaining color information of a central area or a specific area of a display panel in the prior art, such as (but not limited to) the operation of the invention: KONICA MINOLTA CA-310 color analyzer; the second color analyzer preferably obtains color information for the entire area of the display panel, such as (but not limiting to the operation of the invention): KONICA MINOLTA CA-2000 color analyzer, a two-dimensional color analyzer.
According to an embodiment, the first color analyzer is shown in fig. 1, which shows that the first color analyzer 15 is installed in front of a display panel of a display 10, the display 10 is a Liquid Crystal Display (LCD) using a Light Emitting Diode (LED) as a backlight module, the first color analyzer 15 is used to measure color information of a central area (or other specific areas) of the display 10, and the overall pixel performance in the area, such as chroma (chromaticity) and brightness (luminance), can be adjusted according to a calibration target preset by the first color analyzer for the display. In practice, the color information may include a brightness characteristic represented by a gamma curve, and the chroma may be a parameter adjusted by the first color analyzer, such as Tristimulus values (Tristimulus values) in CIE 1931 color space, and may be three parameters derived from red (R), green (G) and blue (B).
FIG. 2 is a schematic diagram of an exemplary embodiment of a two-dimensional color analyzer used in the method for calibrating color temperature matching of a display panel. Unlike the first color analyzer 15, the second color analyzer 20 is shown as a two-dimensional color analyzer, and the second color analyzer 20 can obtain the color information of the whole area of the display panel of the display 10 by photographing or scanning at a distance from the display 10.
In the panel color temperature matching correction system applying the first color analyzer and the second color analyzer, the system can be divided into two parts, namely, an offline mode (offline mode) and an online mode (online mode), the offline mode is used to determine the human eye sensing target, and the online mode is used to correct each display by the same human eye sensing target, which is described with reference to fig. 3 and fig. 4.
Fig. 3 is a schematic view of an embodiment of a color temperature matching calibration system for obtaining a calibration target in an off-line mode, in which a plurality of displays P1, P2, … PN (at least two displays may be provided by different panel suppliers) are shown, each display obtains color information by respectively capturing and converting the color information by a first color analyzer 301 and a second color analyzer 302, and calculates a modified calibration target 307 by a multi-panel color calculator 305.
In this embodiment, each of the displays P1, P2, … PN obtains the color value of a specific region of the first color analyzer 301, the specific region may be, for example, a portion near the center of the display region of the display, the color analysis (using the first color analyzer or the second color analyzer) is a white sample of the CIE 1931 xyY color space, and the W value expressed by the following equation may be the color information obtained by converting the white color temperature information of x, y, etc. in the CIE 1931 color space.
For example, white is sampled in the xyz color space, for example, color temperature (color temperature) information is obtained by taking or scanning the color of 6500K of sunlight (x is 0.313 and y is 0.329), and the color temperature information is obtained byThe color temperature and color value conversion formula of equation 1 is calculated and converted into a color value, the general white sampling value can be in an xyz color space, equation 1 aims to convert the target white color temperature into the xyz color space, and the corrected target white is the human eye feeling, that is, the human eye feeling is converted into an actual calculation value, in order to correct the problem of inconsistent human eye feeling, equation 1 is used to convert the corrected target white into the xyz color space for operation, and a new target is corrected. Then, the value W is obtained according to the color value of the specific region of each display P1, P2, … PNc_CA_P1、Wc_CA_P2、…Wc_CA_PN. The second color analyzer 302 is shown as a two-dimensional color analyzer, and the second color analyzer 302 obtains color values of the whole area of the display panel of each of the displays P1, P2, … PN, wherein the color values can also be derived from the color temperature information by operating equation 1. In this case, the full-area color value of each display is obtained, and the specific-area color value of each display in the specific area obtained by the second color analyzer is obtained, and the full-area color information of each display is obtained (W)p_2D_CA_P1、Wp_2D_CA_P2、…Wp_2D_CA_PN) The specific region (e.g., the central region) obtained by the first color analyzer 301 may be targeted.
Equation 1 shows a formula for converting color temperature into x, y, etc. color values in the color space CIE 1931 xyY. Equation 1:
that is, the first color analyzer 301 and the second color analyzer 302 both obtain the specific region color values of the specific regions (e.g. the central region) of the displays P1, P2, … PN, and the value is Wc_CA_P1、Wc_CA_P2、…Wc_CA_PNThe second color analyzer 302 also obtains the full-area color value of each display, which is Wp_2D_CA_P1、Wp_2D_CA_P2、…Wp_2D_CA_PN. The first color analyzer 301 has a calibration target (W) set thereinc_CA_target)。
Thus, in the panel color temperature matching correction method, the correction target (W) can be further corrected according toc_CA_target) Obtain a new correction target (W)p_2D_CA_new_target)307, the method runs equation 2 as in the multi-panel color calculator 305.
According to equation 2, for example, for display P1, the color value (W) of a particular region (e.g., the center region) of display P1 derived by second color analyzer 302 may be first calculatedc_2D_CA_P1) And the first color analyzer 301 obtains the color value (W) of the same specific region (e.g. the central region) of the display P1c_CA_P1) Difference (W) of (A)c_2D_CA_P1-Wc_CA_P1) (ii) a Calculating the second color analyzer 302 yields the full area color value (W) of display P1p_2D_CA_P1) And the second color analyzer 302 to obtain the color value (W) of the specific region of the display P1c_2D_CA_P1) Another difference (W) betweenp_2D_CA_P1-Wc_2D_CA_P1) The sum of the above two differences ((W)c_2D_CA_P1-Wc_CA_P1)+(Wp_2D_CA_P1-Wc_2D_CA_P1) Plus a target value (W) set in a specific area (e.g., a central area) from the first color analyzerc_CA_target) Thus, a full-area target value (W1) for display P1 from second color analyzer 302 can be obtainedp_2D_CA_P1_target)。
Equation 2:
Wp_2D_CA_P1_target=Wc_CA_target+(Wc_2D_CA_P1-Wc_CA_P1)+(Wp_2D_CA_P1-Wc_2D_CA_P1)
from equation 2, the full-area target value (W) generated by the second color analyzer 302 for display P2 can be derived by analogyp_2D_CA_P2_target) Until a full-area target value (W) is generated for the display PNp_2D_CA_PN_target)。
In the multi-panel color calculator 205, as shown in equation 3, the sum total (W) of the full-area target values of the display panels in the respective displays P1, P2, … PN is obtained by the second color analyzer 302p_2D_CA_P1_target+Wp_2D_CA_P2_target+…+Wp_2D_CA_PN_target) After additionObtain the average (divided by N), which is the new full-area color target value (W) for the second color analyzer 302p_2D_CA_new_target). Thus, the final calibration target 307 is shown in FIG. 3.
Equation 3:
Wp_2D_CA_new_target=(Wp_2D_CA_P1_target+Wp_2D_CA_P2_target+…+Wp_2D_CA_PN_target)/N
after the panel color temperature matching correction system shown in fig. 3 obtains the correction target in the off-line mode, the panel color temperature matching correction system enters the on-line mode, and then the panel color temperature matching correction system shown in fig. 4 is referred to the on-line mode to obtain the corrected color parameters.
Referring to the implementation example of the above equation, the new full-area color target value (W) is obtained from the panel color temperature matching correction system in the off-line modep_2D_CA_new_target) Thereafter, each display panel of each display P1, P2, … PN can be adjusted according to the new full-area color target value (W)p_2D_CA_new_target) The correction target for the color analysis of the display panel of each display is calculated (307, fig. 3). Then, as shown in fig. 4, the color values of the specific region or the whole region obtained by the different color analyzers (401,402) enter a color correction process 403, and a correction target 405 obtained by equation 3 in the above embodiment is introduced to obtain corrected color parameters 407, and further obtain display parameters for driving the display PN.
The first color analyzer 401 measures a specific region color value (W) of a specific region in the display region of the display PN, taking the display PN as an examplec_CA_PN) The first color analyzer 401 is a color analyzer, and a specific area such as a central area is a region commonly used to represent the PN color information of the whole display; the panel color temperature matching calibration system then measures the entire display area of the display PN with the second color analyzer 402 to obtain a total area color value (W)p_2D_CA_PN) The second color analyzer 402 is, for example, a two-dimensional color analyzer.
Then, directly converting the color value of the whole region to obtain the corresponding color valueAnother specific region color value (W) of the specific regionc_2D_CA_PN) This is the specific region color value among the full region color values measured by the second color analyzer 402. At this time, the panel color temperature matching correction system introduces the correction target 405 obtained in the off-line mode, i.e. the new full-area color target (W) obtained by the above equation 3, into the color correction process 403p_2D_CA_new_target)。
Thereafter, in the color correction process 403, equation 4 is performed, except that the above-mentioned full-region color target value (W) is introducedp_2D_CA_new_target) In addition, the full-area color values and the specific area (e.g. the central area) color values generated by the first color analyzer 401 and the second color analyzer 402 are introduced to revise the calibration targets (originally, W) of the PN display panels of each displayc_CA_target) To derive a new correction target (W)c_CA_PN_target) According to the object, the hardware parameters of the Pre-Gamma (Pre Gamma, Color Transfer Matrix (Color Transfer Matrix) and Post-Gamma (Post Gamma) can be adjusted by the correction parameters to achieve the Color space object and the display human eye can feel the same display effect, such as white balance.
Equation 4:
Wc_CA_PN_target=Wp_2D_CA_new_target-((Wc_2D_CA_PN-Wc_CA_PN)+(Wp_2D_CA_PN-Wc_2D_CA_PN))
equation 4 describes the calculation process for obtaining the color target value of a specific area on the display panel of the display PN (representing each display), and the flowchart of the embodiment of the panel color temperature matching correction method described with reference to fig. 5 is also included.
In the embodiment of color calibration process, the first color analyzer measures the specific region in the display PN to obtain the color value (W) of the specific regionc_CA_PN) And may be referred to as a first region-specific color value (step S501). On the other hand, the full-area color value (W) measured by the second color analyzer for the display PNp_2D_CA_PN) (step S503), and then the color value (W) of the second specific region in the same specific region as that in step S501 is extracted from the color values of the whole regionc_2D_CA_PN) The specific areaThe color value of (A) is measured by the second color analyzer (step S505), and the color value of the first specific region (W) obtained by the first color analyzerc_CA_PN) And (6) distinguishing. The manner of obtaining the color value of the second specific region can be obtained, for example, by performing a specific algorithm according to the color value of the whole region and referring to the proportional relationship between the size of the display panel and the size of the specific region available to the first color analyzer.
At this time, a first difference (W) between the color value of the first specific region obtained by the first color analyzer and the color value of the first specific region obtained by the second color analyzer is calculatedc_2D_CA_PN-Wc_CA_PN) (step S507), and calculating a second difference (W) between the full-area color value previously measured by the second color analyzer on the display PN and the second specific-area color value on the display PN obtained thereinp_2D_CA_PN-Wc_2D_CA_PN) (step S509).
Then, the calibration target set by the initial first color analyzer for the display may be adjusted according to a correlation between the first difference and the second difference, for example, a sum of the differences obtained by adding the first difference and the second difference, so as to generate a new calibration target for calibrating the display parameters of the display.
If the sum of the first difference and the second difference (called difference sum) is taken as an example, the new full-region color target value (W) obtained according to equation 3 can be continuedp_2D_CA_new_target) The new full-area color target value is subtracted by the sum of the first difference and the second difference (step S511), so that the correction target (W) of the display PN in the specific area is re-correctedc_CA_PN_target) (step S513), that is, the new calibration target is applied to the first Color analyzer to perform Color parameter adjustment on a specific area of each display, for example, to adjust the gamma parameter, and to adjust the Color conversion parameter in the Color conversion Matrix (Color Transfer Matrix), so as to form the firmware parameter applied to the display chip of the display PN, so as to modify the Color representation, including chroma and brightness, of the corresponding display.
Therefore, the new calibration target obtained by the panel color temperature matching calibration method can adjust the tristimulus stimulus felt by human eyes to the color target wanted by a client (manufacturer) when the first color analyzer is used for carrying out the color adjustment of the display originally.
According to the above embodiments, in the technique of obtaining color information and adjusting the calibration target, the color values of the full region and the specific region of the display can be obtained from color information of various color spaces, and the manner described in the embodiments is not intended to limit the implementable scope of the invention.
In summary, the panel color temperature matching correction system described in the above embodiment is a correction structure that obtains full-screen chromaticity information by knowing a two-dimensional color analyzer (2D color analyzer) and partial-area chromaticity information obtained by a general color analyzer (color analyzer) to achieve the same target color gamut and human eye feeling of the display. Compared with the conventional color correction instrument which only corrects a certain part of the display panel, such as the central part, which is a part that the human eyes are more attentive than the conventional color correction instrument, but the human eyes not only see a certain part of the panel, so that the human eyes still may feel the difference of the whole display result if only the specific area is corrected, the panel color temperature matching correction system proposed in the disclosure additionally adopts a specific color analyzer, such as a two-dimensional color analyzer (2D color analyzer), wherein the problem that the two-dimensional color analyzer needs longer measurement time than the conventional color analyzer (color analyzer) is avoided through a new correction process, and the defects in the measurement of the conventional color analyzer are compensated, and the correction target of each display by the color analyzer is re-corrected, and besides the color expression of the originally considered specific area is still maintained, the obtained corrected color parameters can enable the human eyes to display the whole display of the display (such as color temperature, color, and the like) of the, Color) has the same or similar perception.
The disclosure is only a preferred embodiment of the invention and should not be taken as limiting the scope of the invention, so that the invention is not limited by the disclosure of the specification and drawings.