CN116684563A - Light quality correction method and system for image display and image display method and system - Google Patents

Light quality correction method and system for image display and image display method and system Download PDF

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CN116684563A
CN116684563A CN202310934442.2A CN202310934442A CN116684563A CN 116684563 A CN116684563 A CN 116684563A CN 202310934442 A CN202310934442 A CN 202310934442A CN 116684563 A CN116684563 A CN 116684563A
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target
corrected
transmittance
light quality
light
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CN116684563B (en
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张锦
沈翰林
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Chengdu Jiutian Huaxin Technology Co ltd
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Chengdu Jiutian Huaxin Technology Co ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/64—Circuits for processing colour signals
    • H04N9/646—Circuits for processing colour signals for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/64—Circuits for processing colour signals
    • H04N9/67—Circuits for processing colour signals for matrixing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/64—Circuits for processing colour signals
    • H04N9/73—Colour balance circuits, e.g. white balance circuits or colour temperature control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/77—Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Liquid Crystal Display Device Control (AREA)

Abstract

The application relates to a light quality correction method and system for image display and an image display method and system. The light quality correction method comprises the following steps: acquiring an optical quality imaging target of an object to be corrected in real time; calculating the target transmittance of the to-be-corrected object based on the operation relation between the transmittance of the to-be-corrected object and the light quality imaging target; calculating a target gray-scale value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray-scale value and the Gamma coefficient and the target transmittance; and correcting the object to be corrected by taking the target gray level value as an updated gray level value. The light quality correction method can be applied to the light quality problem caused by the transmissivity error, so that the correction effect on the light quality such as color cast, brightness and the like is improved.

Description

Light quality correction method and system for image display and image display method and system
Technical Field
The application relates to the field of image display, in particular to a light quality correction method and system for image display and an image display method and system.
Background
Active light emitting devices, such as liquid crystal display devices, projectors, etc., may cause uneven brightness in different display areas when light passes through due to transmittance deviation caused by consistency of manufacturing factors.
The conventional De-Mura technology can solve the problem of uneven brightness within a certain range, but is limited to a compensation mechanism, and cannot effectively solve Mura such as uneven chromaticity. The color bias Mura shows that the light intensity ratio of RGB three primary colors of a color bias area is inconsistent with the required ratio of white light in brightness, and for the spectral color of the equal energy white light, the unit energy of the RGB three primary colors is normal white. The existing De-Mura method generally approximates acquired screen brightness data to a target value by taking the brightness of a central area of a screen as the target value, and only considers the consistency in brightness, but does not consider the influence of RGB three-primary-color brightness proportion on chromaticity HUE, so that the traditional De-Mura method has limited improvement effect on color cast Mura.
The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present application and is not intended to represent an admission that the foregoing is prior art.
Disclosure of Invention
The application aims to solve the technical problem of providing a method and a system for correcting the light quality of image display, and a method and a system for displaying the image, which have the characteristic of better correcting effects on the light quality such as color cast, brightness and the like.
In a first aspect, an embodiment provides a light quality correction method for image display, including:
acquiring an optical quality imaging target of an object to be corrected in real time;
calculating the target transmittance of the to-be-corrected object based on the operation relation between the transmittance of the to-be-corrected object and the light quality imaging target;
calculating a target gray-scale value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray-scale value and the Gamma coefficient and the target transmittance;
and correcting the object to be corrected by taking the target gray level value as an updated gray level value.
In one embodiment, the acquiring the optical quality imaging target of the object to be corrected includes:
acquiring a light quality imaging target of each pixel point of data to be displayed of an object to be corrected;
the target transmittance comprises the target transmittance of each pixel, the Gamma coefficient comprises the Gamma coefficient of each pixel, and the target gray scale value comprises the target gray scale value of each pixel.
In one embodiment, the method further comprises:
and acquiring data to be displayed of the object to be corrected in real time, and correcting the object to be corrected based on the data to be displayed of each frame.
In one embodiment, the acquiring, in real time, the optical quality imaging target of the object to be corrected includes:
acquiring data to be displayed of an object to be corrected;
calculating the light color gray scale value of each pixel in the image based on the data to be displayed;
converting the light color gray scale value into a first XYZ tristimulus value based on a color space to which the light color gray scale value belongs;
and taking the first XYZ tristimulus values as a light quality imaging target of an object to be corrected.
In one embodiment, the acquiring, in real time, the optical quality imaging target of the object to be corrected includes:
acquiring data to be displayed of an object to be corrected;
calculating the light color gray scale value of each pixel in the image based on the data to be displayed;
converting the light color gray scale value into a first XYZ tristimulus value based on a color space to which the light color gray scale value belongs;
and mapping the first XYZ tristimulus values to the light quality imaging of the object to be corrected to obtain second XYZ tristimulus values, and taking the second XYZ tristimulus values as a light quality imaging target.
In one embodiment, said mapping the first XYZ tristimulus values to the light quality imaging of the object to be corrected to obtain second XYZ tristimulus values comprises:
and mapping the target brightness based on the first XYZ tristimulus values to a light quality imaging target relation of the display brightness of the object to be corrected so as to obtain the light quality imaging target.
In one embodiment, the calculating, based on the operational relationship between the transmittance of the object to be corrected and the optical quality imaging target, the target transmittance of the object to be corrected includes:
based on the matrix operation relation between the transmittance T OF the object to be corrected and the optical quality imaging target OF under the condition that the image resolution is M x N
。
Calculating the target transmittance of the object to be corrected；
wherein ,（m，n) For the coordinate of a certain pixel point, M is more than or equal to 1 and less than or equal to M, N is more than or equal to 1 and less than or equal to N,is the coordinates of%m，n) The transmittance T OF the pixel points OF (1) and the matrix operation relation OF the optical quality imaging target OF,Ithe number of subfields for collecting the backlight base color light of the object to be corrected is determined by the number of backlight base color light, < ->，iFor sub-field index, & gt>，/>Obtained by converting the light color gray scale value of the data to be displayed into XYZ tristimulus values ++>Is the coordinates of%m，n) X stimulus value of pixel point of +.>Is the coordinates of%m，n) Y stimulus value of pixel point of +.>Is the coordinates of%m，n) Is used for the Z-stimulus value of the pixel point,is the coordinates of%m，n) Is the pixel point of (2)iX stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iY stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iZ stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iTarget transmittance of each subfield.
In one embodiment, the Gamma coefficient is calculated from an ideal correspondence between the transmittance, the gray scale value, and the Gamma coefficient.
In one embodiment, the ideal correspondence between the transmittance, the gray scale value and the Gamma coefficient includes:
，
wherein ,is the coordinates of%m，n) Ideal transmittance of pixel point of +.>Is the coordinates of%m，n) Gamma coefficient of pixel point D of (2) g The gray scale value is selected to allow the transmittance to approach the ideal transmittance indefinitely.
In one embodiment, the correction correspondence relationship between the transmittance, the gray-scale value and the Gamma coefficient includes:
，
wherein ,is the coordinates of%m，n) Gamma coefficient of pixel point of +.>Is the coordinates of%m，n) Is used for the target transmittance of the pixel points of (a),Ithe number of subfields for collecting the backlight base color light of the object to be corrected is determined by the number of backlight base color light, < ->，iFor sub-field index, & gt>，/>Is the coordinates of%m，n) Is the pixel point of (2)iTarget transmittance of individual subfields, +.>Is the coordinates of%m，n) Target gray-scale value of pixel of +.>Is the coordinates of%m，n) Is the pixel point of (2)iTarget gray scale values for each subfield.
In a second aspect, an embodiment provides a light quality correction system for image display, including:
the light quality imaging target acquisition module is used for acquiring a light quality imaging target of an object to be corrected;
the target transmittance acquisition module is used for calculating the target transmittance of the to-be-corrected object based on the operation relation between the transmittance of the to-be-corrected object and the light quality imaging target;
the target gray level value acquisition module is used for calculating the target gray level value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray level value and the Gamma coefficient and the target transmittance;
and the gray level value updating module is used for correcting the object to be corrected by taking the target gray level value as an updated gray level value.
In a third aspect, an embodiment provides an image display method, including:
acquiring data to be displayed;
and based on the data to be displayed, displaying the data to be displayed after carrying out light quality correction on the display unit by adopting any one of the light quality correction methods for image display.
In a fourth aspect, an embodiment provides an image display system, including:
the display unit is used for acquiring data to be displayed and displaying the data;
and the processor is used for acquiring the data to be displayed in real time and carrying out light quality correction on the display unit according to any one of the light quality correction methods for image display.
In one embodiment, the image display system further comprises:
and the image acquisition device is used for photographing the display interface of the display unit so as to at least acquire the gray scale value of the backlight field substrate color light of the display unit.
In a fifth aspect, an embodiment provides a computer readable storage medium having a program stored therein, the program being capable of being loaded by a processor and performing any one of the above-described light quality correction method and/or image display method for image display.
The beneficial effects of the application are as follows:
based on the light quality correction method, as the light quality imaging target is determined by the three stimulus of the back light field of the object to be corrected and the corresponding transmittance, the method can be applied to the light quality problem caused by the transmittance error, thereby improving the correction effect on the light quality such as color cast, brightness and the like.
Drawings
FIG. 1 is a flow chart of a light quality correction method in the prior art;
FIG. 2 is a schematic diagram of an image display system to which the light quality correction method of the present application is applied;
FIG. 3 is a flow chart of a light quality correction method according to an embodiment of the application;
FIG. 4 is a flow chart of a method according to an embodiment of step S10 in the embodiment of FIG. 3.
Detailed Description
The application will be described in further detail below with reference to the drawings by means of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, related operations of the present application have not been shown or described in the specification in order to avoid obscuring the core portions of the present application, and may be unnecessary to persons skilled in the art from a detailed description of the related operations, which may be presented in the description and general knowledge of one skilled in the art.
Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.
The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The term "coupled" as used herein includes both direct and indirect coupling (coupling), unless otherwise indicated.
In order to facilitate the explanation of the inventive concept of the present application, a brief explanation of the light quality correction technique of image display is provided below.
Conventional light quality correction techniques, such as De-mura techniques, are based on conventional LCD panels, where the backlight is a white light source that reaches the LCD panel through a light transmissive strip or panel. Under this mechanism, the backlight is highly uniform, highly uniform white light. Such Mura phenomenon is therefore typical of pure light-dark non-uniformity. The traditional deMura technology can solve the problem of uneven brightness in a certain range. The main method is to take photos under white balance, divide N grades of original data with different brightness, compare and find acceptable compensation data, and store the compensation data into an external memory such as Flash. When the input gray level changes, searching the output compensation value of the De-mura table to correct the uneven brightness of the display picture.
Based on the conventional De-Mura logic, the main flow of the color cast De-Mura compensation technique is shown in fig. 1. In the main process, gray data of R, G and B are photographed by a black-and-white camera. And selecting the center point of the screen as a reference point of target brightness and chromaticity, and converting the center reference point and the bias point RGB coordinate system into an XYZ coordinate system to obtain respective color coordinates. And establishing a constraint evaluation formula with minimum brightness loss in the RGB coordinate system. And establishing a constraint evaluation formula with minimum chromaticity loss in the XYZ coordinate system. And finally, carrying out overall loss minimum constraint on the two formulas to obtain corresponding XYZ tristimulus values for correcting the color cast, converting the tristimulus values into an RGB coordinate system, and then carrying out Gamma coefficient adaptation to obtain an RGB gray scale compensation value to be adjusted in a final color cast region.
The applicant found in the research that the technical scheme has the following defects:
in the first aspect, since the consistency of the manufacturing factors of the lcd screen fluctuates, the transmittance of the liquid crystal molecules corresponding to the pixels deviates, and when light passes through, uneven brightness will occur in different display areas of the screen, and the above technical solution cannot effectively solve the problem.
In a second aspect, the central reference point is selected or the manner in which the reference points are fixed is selected such that the application is not universal. For example, after the further developed color shift type De-Mura is subjected to De-Mura correction under the white balance, the correction data adjusts the gray scale value according to the brightness distance difference between the fixed target and the color shift point, but when other color fields or playing display contents, the target changes, the brightness and the color coordinate distance difference are still calculated according to the previous distance difference, or the target is directly stored and applied to a dynamic picture, the result is distorted, and the fixed reference point is selected and is not applicable to the dynamic picture. The reference point is calculated by re-shooting, and mass production and real-time performance are not realized.
In the third aspect, for a display screen adopting an RGB backlight, due to the distribution design of the backlight LEDs and the influence on different refractive indexes of the RGB color light on the optical path, the light superposition is uneven, so that color cast or uneven brightness occurs. In the technical scheme, the default RGB three-color light base color coordinates cannot be changed, so that the method is not suitable for the condition that the RGB three-color light base color coordinates change due to uneven light paths. The color coordinates of the RGB three substrates of the color cast area backlight and the RGB background color coordinate reference point of the central point are changed, so that when the RGB is converted into RGB through XYZ, the condition of uncompensated position is necessarily generated, and even failure or color cast is more obvious.
In the fourth aspect, the Gamma coefficient used for calculation does not take into account the coefficient variation caused by the reference temperature variation and the temperature unevenness of the screen display area, and the same Gamma coefficient is used for the whole screen. In practice, all display products have their actual Gamma coefficients changed due to different temperatures. In particular, in LCD products, the transmittance of liquid crystal varies nonlinearly due to different temperatures, so that the Gamma coefficients are different under different temperature conditions. The conventional De-Mura logic does not consider that the same screen has different temperature intervals, and the temperature intervals which do not pass through the same screen have different Gamma coefficients in different temperature intervals. Therefore, taking a Gamma coefficient as a matter of moving, the compensation effect is actually shifted in the areas with different temperatures, and even the effect of the De-Mura cannot be achieved at all, so that the compensation effect is disabled.
Based on the above-mentioned problems, in one embodiment of the present application, a method for correcting the light quality of an image display is provided, in which the light quality imaging target is determined by XYZ three stimuli of a backlight field and corresponding transmittance, so that the scheme of the present application can solve the light quality problem caused by the transmittance error, and is suitable for not only color shift and brightness non-uniformity caused by the transmittance error, backlight brightness error and light path error caused by the liquid crystal screen manufacturing process, but also the imaging principle and device under the traditional spatial color mixing, especially time color mixing, so as to achieve the effect of better correcting the light quality such as color shift and brightness.
For convenience of explanation of the light quality correction method, the application environment will be described first, and referring to fig. 2, the light quality correction method can be applied to an image display system, which includes a display unit 01 and a processor 02. The display unit 01 may be one or more of an LED backlight+lcd, a conventional backlight+lcd, LCOS, micro led+lcd, a projection display device, etc., for acquiring data to be displayed and displaying the data; the processor 02 may have one or more processors for acquiring data to be displayed in real time and performing light quality correction on the display unit 01 according to the light quality correction method provided by the present application.
In one embodiment, the image display system further includes an image capturing device 03, configured to take a picture of the display interface of the display unit 01, so as to at least obtain a gray-scale value of the backlight field base color light of the display unit.
It will be appreciated by those skilled in the art that the hardware architecture of the image display system shown in fig. 2 does not constitute a limitation on the video image quality detection apparatus, and may include more or fewer components than shown, or may combine certain components, or may have a different arrangement of components.
Referring to fig. 3, the light quality correction method applied to the image display system may include:
step S10, acquiring an optical quality imaging target of an object to be corrected in real time.
In some embodiments, the object to be modified may be a display device such as an LED backlight+lcd, a conventional backlight+lcd, an LCOS, a micro led+lcd, or a projection device, or may be a part of the display area in the foregoing display device or the projection device.
In some embodiments, the light quality imaging target may be a chromaticity imaging target, a luminance imaging target, or the like. For convenience of clear description, the following will specifically describe an example in which the correction object is the entire display unit of the display device and the light quality imaging target is the chromaticity and luminance imaging target. It is understood that other embodiments may be utilized within the scope of the present application.
For a method for obtaining an optical quality imaging target of a display unit, some methods of the prior art may be adopted, and a new method is provided in an embodiment of the present application, please refer to fig. 4, which specifically includes:
step S101, obtaining data to be displayed of an object to be corrected.
And acquiring the data to be displayed of the picture to be displayed of the display unit in real time. In some embodiments, whether there is valid display data input is detected in real time, and if so, the valid display data is obtained. It will be appreciated that the active display data may be a single-frame still display or a video frame of a dynamic display.
Step S102, calculating the light color gray scale value of each pixel in the image based on the data to be displayed.
The light color gray scale values may be RGB gray scale values or CMY gray scale values, and for convenience of clarity of description, RGB is taken as an example for specific description.
In some embodiments, the RGB gray-scale values of the effective display data may be calculated in terms of pixel areas, and in one embodiment of the present application, the RGB gray-scale values of each pixel in the image are calculated based on the acquired effective display data.
Each pixel of the image content is adopted as a chromaticity and brightness target under the pixel, instead of adopting chromaticity and brightness of a fixed reference point as a full-pixel target, so that the target can change in real time along with the input image content, and the light quality correction method is more suitable for dynamic pictures and has instantaneity and universality.
Step S103, converting the light color gray scale value into a first XYZ tristimulus value based on the color space to which the light color gray scale value belongs.
The RGB gray scale value of each pixel of the real-time image content is converted into XYZ coordinate space through the color space (such as sRGB) to which the RGB gray scale value belongs, so that the RGB gray scale value is taken as an imaging target, that is, each pixel in the picture has respective chromaticity and brightness targets.
Step S104, taking the first XYZ tristimulus values as a light quality imaging target of an object to be corrected.
Taking the real-time image resolution M x N as an example, each pixel has its own chromaticity and luminance target values at that resolutionO m,n The coordinates are%m，n) Light quality imaging target of pixel points of (2)Conversion into XYZ tristimulus values based on the image content data RGB, there is +.>, wherein ,Sfor the conversion matrix of sRGB to XYZ, a different conversion matrix, such as Adobe RGB, may be set according to the color space of the image content.RGB m,n Is the coordinates of%m，n) Gray scale values of pixels of (a). (m，n) For the coordinate of a pixel point, M is more than or equal to 1 and less than or equal to M, N is more than or equal to 1 and less than or equal to N, and the coordinate is more than or equal to 1 and less than or equal to N>Is the coordinates of%m，n) X stimulus value of pixel point of +.>Is the coordinates of%m，n) Y stimulus value of pixel point of +.>Is the coordinates of%m，n) Z stimulus values of the pixel points of (2). Then get
（1）。
wherein ,gamma coefficients used for the corresponding color space are stored for the image content. Intended target for arbitrary pixelsO m,n Is>And brightness->Can be obtained.
Because the theoretical and actual brightness of the brightness in the light quality imaging target are different, in some embodiments, the first XYZ tristimulus values are mapped to the light quality imaging OP to be corrected m,n Obtaining a second XYZ tristimulus value and taking the second XYZ tristimulus value as a light quality imaging target, comprising:
mapping the target brightness based on the first XYZ tristimulus values to a light quality imaging target relation of display brightness of the object to be corrected to obtain a light quality imaging target
（2）。
In one embodiment, the luminance conversion coefficient k=yp may be obtained based on a ratio of the highest luminance obtained under the same photosensitive characteristic of the image capturing device and the theoretical highest display luminance of the display unit max /Y max. wherein ,Ymax Is the theoretical maximum brightness value, YP, at gray scale (255 ) max Can be used forFor camera pair Y max Brightness value under photographing. In one embodiment, K obtained at the brightest white field (i.e., gray scale (255, 255)) may be stored in the value Flash at a display resolution m×n.
In this embodiment, for any ofO m,n Light quality imaging for conversion to an object to be processedOP m,n The same brightness conversion coefficient K is adopted, and K is fixed. Based on this, in one embodiment of the present application, a new method for obtaining the luminance conversion coefficient K is provided, which specifically includes: establishing YP using polynomial fitting max and Ymax Mapping relationships between, i.eYP max= f(Y max )Thereby obtaining a luminance conversion coefficient k=yp max /Y max . In the case of polynomial fitting, the resulting luminance conversion coefficient K is not fixed for anyO m,n Light quality imaging for conversion to an object to be processedOP m,n And different brightness conversion coefficients K are adopted, so that the applicability is better.
Step S20, calculating the target transmittance of the object to be corrected based on the operation relation between the transmittance of the object to be corrected and the light quality imaging target.
In one embodiment of the application, the transmittance is introduced to establish an operation relationship based on the transmittance of the object to be corrected and the light quality imaging target, so as to calculate the target transmittance of the corrected object. The operational relationship can be established based on the prior art method, and in one embodiment OF the present application, by the above formula (2), the optical quality imaging target OF to be corrected is as follows m,n The data obtained under the same photographic camera sensitization characteristic with the background color light of the backlight field, thereby obtaining a new target transmittance calculation method, which comprises the following steps:
based on the matrix operation relation between the transmittance T OF the object to be corrected and the optical quality imaging target OF under the condition that the image resolution is M x N
（3）
Calculating the target transmittance of the object to be corrected；
wherein ,is the coordinates of%m，n) The transmittance T OF the pixel points OF (1) and the matrix operation relation OF the optical quality imaging target OF,Ithe number of subfields for collecting the backlight base color light of the object to be corrected is determined by the number of backlight base color light, < ->，iFor sub-field index, & gt>，/>Obtained by converting the light color gray scale value of the data to be displayed into XYZ tristimulus values ++>Is the coordinates of%m，n) X stimulus value of pixel point of +.>Is the coordinates of%m，n) Is used for the Y stimulus value of the pixel point of (c),is the coordinates of%m，n) Z stimulus value of pixel point of +.>Is the coordinates of%m，n) Is the pixel point of (2)iX stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iY stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iZ stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iTarget transmittance of each subfield.
In formula (3), I may be 1, for example, in the case of only a white field or a black field, I may also be 2, for example, in the case of only a white field or a black field, I may also be 4, for example, in the case of red, green, blue, and white fields, I may also be 5, for example, in the case of red, green, blue, white, and black fields, which may be specifically set according to the need, and will not be described herein. In the following, i=3, and a case including red, green, and blue fields will be described as an example.
In the case where the backlight field base color light includes three fields OF red, green, and blue, the light quality imaging target OF to be corrected is m,n And backlight field base color light BL 1 (Red field), BL 2 (Green field) and BL 3 The (blue field) is the data obtained under the photosensitive characteristic OF the same photographic camera, and the matrix operation relation between the backlight BL and the target OF is established by introducing three field transmittance T
（4）
Calculated therefromThe three-field base backlight transmittance required to achieve chromaticity and luminance targets for this subpixel.
According to the method for acquiring the light quality imaging target, the light quality imaging target is determined by the three stimulus of the back light field of the object to be corrected and the corresponding transmittance, so that the method can be applied to the light quality problem caused by the transmittance error, and the correction effect on the light quality such as color cast, brightness and the like is improved.
Step S30, calculating the target gray scale value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray scale value and the Gamma coefficient and the target transmittance.
To obtain the transmittance of the pixel positionLower corresponding three-field gray scale value +.>Both of which need to be converted. The conversion relation of the target gray scale value of the object to be corrected can be obtained by adopting a related method in the prior art, and in a specific embodiment of the application, a new correction corresponding relation based on the transmittance, the gray scale value and the Gamma coefficient is provided, so as to obtain the target gray scale value of the object to be corrected based on the target transmittance through calculation, which specifically comprises the following steps:
（5），
wherein ,is the coordinates of%m，n) Gamma coefficient of pixel point of +.>Is the coordinates of%m，n) Target transmittance of pixel point of +.>Is the coordinates of%m，n) Target gray scale values for pixels of (a).
Based on the relation of the formula (5) and the target gray scale value calculated in the formula (4), introducing Gamma coefficient to obtain the transmittance of the pixel positionLower corresponding three-field gray scale value +.>。
For Gamma coefficients, for a single backlight white light source, only 1 set of Gamma coefficients is used, i.e, wherein ,/>，/>. For multi-backlight light sources, multiple groups of Gamma coefficients, equation (5), are required because different colors of light have an unacceptable transmittance.
In one embodiment, the Gamma coefficient can be obtained according to a theoretical value, however, the applicant finds that, due to the change of the baseline temperature of the display screen and the uneven temperature difference of the distribution area caused by backlight irradiation and heat dissipation factors, the coefficient of the Gamma curve also changes, if the color cast compensation of the whole screen is performed in a mode of not considering the uneven temperature difference distribution, the deviation is generated, so that a new method for calculating the current actual Gamma coefficient is provided in one embodiment of the application, the Gamma coefficient is calculated based on the transmittance, the gray scale value and the actual ideal corresponding relation of the Gamma coefficient, and the updated coefficient is used for the color cast compensation, thereby realizing the full-screen compensation of the uneven temperature difference.
Taking a picture of the three subfields with an image acquisition device such as a camera, the BL can be obtained 1 (Red field), BL 2 (Green field) and BL 3 Three-field base color light (blue field) is converted into XYZ tristimulus values corresponding to the base color light, and then the three-field base color light can be obtained
（6）。
The tristimulus values of the XYZ can be obtained through a photographing camera and calibrated with the actual measurement values of the colorimeter.
BL is to be BL 1 、BL 2 and BL3 And the pixel positions of the effective display area are aligned with the display positions of the pixel contents of the image one by one. The photographing data processing scheme can adopt a target edge detection clipping method, convert the clipped effective display area picture into a front view through perspective transformation, and finally scale to the resolution matched with the display device by using a bilinear interpolation method, thereby realizing the pixel level alignment of photographing data and image content.
In one embodiment, the obtained tristimulus values of the object to be corrected may be stored in the value Flash according to the display resolution m×n.
Based on the matrix relation OF equation (6), OF in equation (4) m,n Light quality imaging OP replaced with the object to be corrected acquired with a photographic camera m,n Tristimulus value data, there is
（7）。
Selecting a suitable oneSo that the transmittance +.>The characteristic that the Gamma curve coefficient is most obvious can be obtained if the transmittance curve switching slope is as close to 0.5 as possible or if the transmittance curve switching slope is around 45 degrees. Will D g The gray-scale data is applied to full-screen three-field display output, and a photographing camera is used for acquiring the light quality imaging OP of the display unit m,n And BL1, BL2, BL3 calculate +.>Finally, the Gamma coefficient of the pixel position is calculated and can be expressed as
（8），
wherein ,is the coordinates of%m，n) The ideal transmittance of the pixel point of (2) can be regarded as 0.5,/or more>Is the coordinates of%m，n) Gamma coefficient of pixel point D of (2) g The gray scale value is selected to allow the transmittance to approach the ideal transmittance indefinitely.
In one embodiment, the Gamma coefficient obtained at the ideal transmittance may be stored in the Flash according to the display resolution m×n.
The Gamma coefficient is calculated based on the actual ideal corresponding relation of the transmittance, the gray level value and the Gamma coefficient of each pixel, and the updated coefficient is used for color cast compensation, so that the full-screen compensation of uneven temperature difference is realized, and the light quality correction method is suitable for color cast and brightness correction after the Gamma coefficient is changed due to the screen reference temperature change and uneven temperature or other factors.
And S40, correcting the object to be corrected by taking the target gray level value as an updated gray level value.
In the step, gray scale values under the resolution of M x N are updated in real time and sent to a display unit for correction of color cast and uneven brightness.
In one embodiment, in the case that the display image of the object to be corrected is a dynamic image, data to be displayed in each frame is acquired in real time, and the above steps S10 to S40 are repeated to correct the object to be corrected based on the data to be displayed in each frame.
Based on the light quality correction method, as the light quality imaging target is determined by three stimulus of a back light field of an object to be corrected and corresponding transmittance, the light quality correction method can be applied to the light quality problem caused by transmittance errors, thereby improving the correction effect on light quality such as color cast, brightness and the like, and simultaneously, the light quality imaging method is also applicable to imaging principles, namely devices under traditional color mixing, especially time color mixing, due to the fact that backlight brightness is an error and color cast and brightness are uneven caused by light path errors. Because each pixel of the image content is adopted as a chromaticity and brightness target under the pixel, rather than adopting chromaticity and brightness of a fixed reference point as a full-pixel target, the target can change in real time along with the input image content, so that the light quality correction method is more suitable for dynamic pictures and has instantaneity and universality. The Gamma coefficient is calculated based on the actual ideal corresponding relation of the transmittance, the gray level value and the Gamma coefficient of each pixel, and the updated coefficient is used for color cast compensation, so that the full-screen compensation of uneven temperature difference is realized, and the light quality correction method is suitable for color cast and brightness correction after the Gamma coefficient is changed due to the screen reference temperature change and uneven temperature or other factors.
In the scheme of the application, based on photographing of the image acquisition device 03, the obtained XYZ tristimulus values of each sub-field pixel of the display unit, the XYZ tristimulus values of the brightest white-field pixel and the calculated Gamma coefficient of the position of each pixel are stored into Flash according to the display resolution m×n, so as to complete preprocessing of data, and then the processes of the steps S10 to S40 are executed in real time, so that each light quality imaging correction of the display unit is completed.
In one embodiment of the present application, there is provided a light quality correction system for image display, including: the light quality imaging target acquisition module is used for acquiring a light quality imaging target of an object to be corrected; the target transmittance acquisition module is used for calculating the target transmittance of the object to be corrected based on the operation relation between the transmittance of the object to be corrected and the light quality imaging target; the target gray level value acquisition module is used for calculating the target gray level value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray level value and the Gamma coefficient and the obtained target transmittance; and the gray level updating module is used for correcting the object to be corrected by taking the obtained target gray level value as an updated gray level value.
An embodiment of the present application provides an image display method including: acquiring data to be displayed; based on the acquired data to be displayed, the data to be displayed is displayed after the light quality correction is carried out on the display unit by adopting any one of the light quality correction methods for image display. Based on the light quality correction method, the uniformity of the light quality such as chromaticity, brightness and the like of the displayed image is better.
An embodiment of the present application provides a computer-readable storage medium in which a program is stored, the stored program being capable of being loaded by a processor and performing any one of the above-described light quality correction method and/or image display method of image display.
Those skilled in the art will appreciate that all or part of the functions of the various methods in the above embodiments may be implemented by hardware, or may be implemented by a computer program. When all or part of the functions in the above embodiments are implemented by means of a computer program, the program may be stored in a computer readable storage medium, and the storage medium may include: read-only memory, random access memory, magnetic disk, optical disk, hard disk, etc., and the program is executed by a computer to realize the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the functions described above can be realized. In addition, when all or part of the functions in the above embodiments are implemented by means of a computer program, the program may be stored in a storage medium such as a server, another computer, a magnetic disk, an optical disk, a flash disk, or a removable hard disk, and the program in the above embodiments may be implemented by downloading or copying the program into a memory of a local device or updating a version of a system of the local device, and when the program in the memory is executed by a processor.
The foregoing description of the application has been presented for purposes of illustration and description, and is not intended to be limiting. Several simple deductions, modifications or substitutions may also be made by a person skilled in the art to which the application pertains, based on the idea of the application.

Claims (14)

1. A light quality correction method for image display, comprising:
acquiring an optical quality imaging target of an object to be corrected in real time;
calculating the target transmittance of the to-be-corrected object based on the operation relation between the transmittance of the to-be-corrected object and the light quality imaging target;
calculating a target gray-scale value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray-scale value and the Gamma coefficient and the target transmittance;
and correcting the object to be corrected by taking the target gray level value as an updated gray level value.
2. The method for correcting the light quality of an image display according to claim 1, wherein said acquiring the light quality imaging target of the object to be corrected comprises:
acquiring a light quality imaging target of each pixel point of data to be displayed of an object to be corrected;
the target transmittance comprises the target transmittance of each pixel, the Gamma coefficient comprises the Gamma coefficient of each pixel, and the target gray scale value comprises the target gray scale value of each pixel.
3. The method for correcting the light quality of an image display according to claim 1, wherein the method further comprises:
and acquiring data to be displayed of the object to be corrected in real time, and correcting the object to be corrected based on the data to be displayed of each frame.
4. The method for correcting the light quality of an image display according to claim 1, wherein said acquiring in real time the light quality imaging target of the object to be corrected comprises:
acquiring data to be displayed of an object to be corrected;
calculating the light color gray scale value of each pixel in the image based on the data to be displayed;
converting the light color gray scale value into a first XYZ tristimulus value based on a color space to which the light color gray scale value belongs;
and taking the first XYZ tristimulus values as a light quality imaging target of an object to be corrected.
5. The method for correcting the light quality of an image display according to claim 1, wherein said acquiring in real time the light quality imaging target of the object to be corrected comprises:
acquiring data to be displayed of an object to be corrected;
calculating the light color gray scale value of each pixel in the image based on the data to be displayed;
converting the light color gray scale value into a first XYZ tristimulus value based on a color space to which the light color gray scale value belongs;
and mapping the first XYZ tristimulus values to the light quality imaging of the object to be corrected to obtain second XYZ tristimulus values, and taking the second XYZ tristimulus values as a light quality imaging target.
6. The method for modifying the light quality of an image display according to claim 5, wherein said mapping the first XYZ tristimulus values to the light quality image of the object to be modified to obtain the second XYZ tristimulus values comprises:
and mapping the target brightness based on the first XYZ tristimulus values to a light quality imaging target relation of the display brightness of the object to be corrected so as to obtain the light quality imaging target.
7. The method for correcting the light quality of an image display according to claim 1, wherein said calculating the target transmittance of the object to be corrected based on the operational relationship between the transmittance of the object to be corrected and the light quality imaging target comprises:
based on the matrix operation relation between the transmittance T OF the object to be corrected and the optical quality imaging target OF under the condition that the image resolution is M x N
，
Calculating the target transmittance of the object to be corrected；
wherein ,（m，n) For the coordinate of a certain pixel point, M is more than or equal to 1 and less than or equal to M, N is more than or equal to 1 and less than or equal to N,is the coordinates of%m，n) The transmittance T OF the pixel points OF (1) and the matrix operation relation OF the optical quality imaging target OF,Ithe number of subfields for collecting the backlight base color light of the object to be corrected is determined by the number of backlight base color light, < ->，iFor sub-field index, & gt>，/>Obtained by converting the light color gray scale value of the data to be displayed into XYZ tristimulus values ++>Is the coordinates of%m，n) Is used for the X stimulus value of the pixel point,is the coordinates of%m，n) Y stimulus value of pixel point of +.>Is the coordinates of%m，n) Is used for the Z-stimulus value of the pixel point,is the coordinates of%m，n) Is the pixel point of (2)iX stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iY stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iZ stimulus value of individual subfields, +.>Is the coordinates of%m，n) Is the pixel point of (2)iTarget transmittance of each subfield.
8. The method for correcting the light quality of an image display according to claim 1, wherein the Gamma coefficient is calculated from an ideal correspondence of transmittance, gray scale value and Gamma coefficient.
9. The method for correcting the light quality of an image display according to claim 8, wherein the ideal correspondence of the transmittance, the gray-scale value and the Gamma coefficient comprises:
，
wherein ,is the coordinates of%m，n) Ideal transmittance of pixel point of +.>Is the coordinates of%m，n) Gamma coefficient of pixel point D of (2) g The gray scale value is selected to allow the transmittance to approach the ideal transmittance indefinitely.
10. The method for correcting the light quality of an image display according to any one of claims 1 to 9, wherein the correction correspondence relationship of the transmittance, the gray-scale value and the Gamma coefficient includes:
，
wherein ,is the coordinates of%m，n) Gamma coefficient of pixel point of +.>Is the coordinates of%m，n) Is used for the target transmittance of the pixel points of (a),Ithe number of subfields for collecting the backlight base color light of the object to be corrected is determined by the number of backlight base color light, < ->，iFor sub-field index, & gt>，/>Is the coordinates of%m，n) Is the pixel point of (2)iTarget transmittance of individual subfields, +.>Is the coordinates of%m，n) Target gray-scale value of pixel of +.>Is the coordinates of%m，n) Is the pixel point of (2)iTarget gray scale values for each subfield.
11. A light quality correction system for image display, comprising:
the light quality imaging target acquisition module is used for acquiring a light quality imaging target of an object to be corrected;
the target transmittance acquisition module is used for calculating the target transmittance of the to-be-corrected object based on the operation relation between the transmittance of the to-be-corrected object and the light quality imaging target;
the target gray level value acquisition module is used for calculating the target gray level value of the object to be corrected based on the correction corresponding relation of the transmittance, the gray level value and the Gamma coefficient and the target transmittance;
and the gray level value updating module is used for correcting the object to be corrected by taking the target gray level value as an updated gray level value.
12. An image display method, comprising:
acquiring data to be displayed;
based on the data to be displayed, the data to be displayed is displayed after the light quality correction is performed on the display unit by using the light quality correction method for image display according to one of claims 1 to 10.
13. An image display system, comprising:
the display unit (01) is used for acquiring data to be displayed and displaying the data;
a processor (02) for acquiring data to be displayed in real time and performing a light quality correction for a display unit according to the light quality correction method of image display as claimed in one of claims 1 to 10.
14. The image display system of claim 13, further comprising:
and the image acquisition device (03) is used for photographing the display interface of the display unit so as to at least acquire the gray scale value of the backlight field substrate color light of the display unit.
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW200916747A (en) * 2007-10-15 2009-04-16 Chunghwa Picture Tubes Ltd Method for calibrating gamma curve
US20120169792A1 (en) * 2009-09-29 2012-07-05 Panasonic Corporation Display device and display method
CN103413539A (en) * 2013-09-04 2013-11-27 青岛海信电器股份有限公司 Control method, control device and display device of backlight drive
CN103676254A (en) * 2013-12-04 2014-03-26 青岛海信电器股份有限公司 See-through display device and driving method thereof, and electronic equipment
CN107680542A (en) * 2017-11-21 2018-02-09 武汉华星光电技术有限公司 A kind of subregion method for controlling backlight thereof and its device
CN109817179A (en) * 2019-03-27 2019-05-28 上海天马微电子有限公司 Liquid crystal display panel brightness adjusting method, regulating system and 3D printing device
WO2021008307A1 (en) * 2019-07-17 2021-01-21 深圳创维－Rgb电子有限公司 Television based on pixel light control, pixel light control method and readable storage medium
CN113438458A (en) * 2021-06-11 2021-09-24 屏丽科技(深圳)有限公司 Method for optimizing initial brightness of time sequence color mixing liquid crystal projection
CN113450713A (en) * 2020-03-25 2021-09-28 北京小米移动软件有限公司 Screen display method and device and gray scale mapping information generation method and device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW200916747A (en) * 2007-10-15 2009-04-16 Chunghwa Picture Tubes Ltd Method for calibrating gamma curve
US20120169792A1 (en) * 2009-09-29 2012-07-05 Panasonic Corporation Display device and display method
CN103413539A (en) * 2013-09-04 2013-11-27 青岛海信电器股份有限公司 Control method, control device and display device of backlight drive
CN103676254A (en) * 2013-12-04 2014-03-26 青岛海信电器股份有限公司 See-through display device and driving method thereof, and electronic equipment
CN107680542A (en) * 2017-11-21 2018-02-09 武汉华星光电技术有限公司 A kind of subregion method for controlling backlight thereof and its device
CN109817179A (en) * 2019-03-27 2019-05-28 上海天马微电子有限公司 Liquid crystal display panel brightness adjusting method, regulating system and 3D printing device
WO2021008307A1 (en) * 2019-07-17 2021-01-21 深圳创维－Rgb电子有限公司 Television based on pixel light control, pixel light control method and readable storage medium
CN113450713A (en) * 2020-03-25 2021-09-28 北京小米移动软件有限公司 Screen display method and device and gray scale mapping information generation method and device
CN113438458A (en) * 2021-06-11 2021-09-24 屏丽科技(深圳)有限公司 Method for optimizing initial brightness of time sequence color mixing liquid crystal projection

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
邱基斯;樊仲维;唐熊忻;: "液晶空间光调制器Gamma曲线的线性化调试算法及其对光束整形的影响", 激光与光电子学进展, no. 06 *

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