CN110648640B - Pixel compensation method, pixel compensation device and display device - Google Patents
Pixel compensation method, pixel compensation device and display device Download PDFInfo
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- CN110648640B CN110648640B CN201910924275.7A CN201910924275A CN110648640B CN 110648640 B CN110648640 B CN 110648640B CN 201910924275 A CN201910924275 A CN 201910924275A CN 110648640 B CN110648640 B CN 110648640B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3607—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
- G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
Abstract
The invention discloses a pixel compensation method, a pixel compensation device and a display device, in the embodiment of the invention, the gray scale of a first pixel can be compensated according to a first preset brightness gray scale function, the gray scale of a second pixel is compensated according to a second preset brightness gray scale function, the compensation of the second pixel corresponding to a dimming area with low brightness and other pixels in different modes is realized, the problems of dark area noise amplification and overcompensation caused by the same compensation mode for each pixel in the prior art are avoided, in addition, when the compensation is carried out on the second pixel, the compensated effect can more truly reflect the picture corresponding to the dark area, and good transition is realized between the picture corresponding to the non-dark area, so that the whole display picture is more exquisite and natural, and the display contrast is improved, the display effect is improved.
Description
Technical Field
The present invention relates to the field of display technologies, and in particular, to a pixel compensation method, a pixel compensation device, and a display device.
Background
The liquid crystal display is a non-self-luminous device, needs to be provided with a backlight module, and can realize the display function by utilizing a backlight source provided by the backlight module. At present, in order to improve the display contrast of the liquid crystal display, a local dimming technology is adopted for the backlight module.
For example, the backlight module may include a light emitting substrate, where light emitting elements arranged in an array are disposed on the light emitting substrate, each light emitting element is used as a light emitting device to provide a backlight source, the light emitting elements on the light emitting substrate are divided into regions to obtain a plurality of dimming regions, and the light emitting luminances of different dimming regions may be independently controlled according to a picture to be displayed. Then, the liquid crystal display panel can perform certain brightness compensation on each pixel according to the brightness of different dimming areas in the backlight module so as to ensure the final display brightness.
However, when the local dimming technique is adopted, there may be a problem that the compensation coefficient of a dark area (i.e., a dimming area with a relatively dark luminance) is too large, so that low luminance noise which is not easily perceived originally is amplified, and finally, the display contrast is reduced. Therefore, how to improve the display contrast of the liquid crystal display is an urgent technical problem to be solved by those skilled in the art.
Disclosure of Invention
The embodiment of the invention provides a pixel compensation method, a pixel compensation device and a display device, which are used for improving the display contrast of a liquid crystal display.
In a first aspect, an embodiment of the present invention provides a pixel compensation method, which is applied to a liquid crystal display device, where the liquid crystal display device includes a display panel and a backlight module, the display panel is located on a light emitting surface of the backlight module, the display panel includes pixels arranged in an array, and the backlight module includes a plurality of light modulation regions; the method comprises the following steps:
acquiring an image to be displayed, and determining the brightness of each light adjusting area according to the image to be displayed;
according to the position corresponding relation between each pixel and each dimming area, determining the pixel corresponding to the dimming area with the brightness not less than the preset brightness as a first pixel, determining the pixel corresponding to the dimming area with the brightness less than the preset brightness as a second pixel, compensating the gray scale of the first pixel according to a first preset brightness gray scale function, and compensating the gray scale of the second pixel according to a second preset brightness gray scale function;
wherein the second preset luminance grayscale function is: and the first preset brightness gray scale function is in a tangent equation corresponding to the preset brightness.
In a second aspect, an embodiment of the present invention provides a pixel compensation device, which is applied to a liquid crystal display device, where the liquid crystal display device includes a display panel and a backlight module, the display panel is located on a light emitting surface of the backlight module, the display panel includes pixels arranged in an array, and the backlight module includes a plurality of light modulation regions; the device includes:
the first unit is used for acquiring an image to be displayed and determining the brightness of each dimming area according to the image to be displayed;
the second unit is used for determining the pixels corresponding to the dimming areas not smaller than the preset brightness as first pixels and determining the pixels corresponding to the dimming areas smaller than the preset brightness as second pixels according to the position corresponding relation between each pixel and each dimming area, compensating the gray scale of the first pixels according to a first preset brightness gray scale function, and compensating the gray scale of the second pixels according to a second preset brightness gray scale function;
wherein the second preset luminance grayscale function is: and the first preset brightness gray scale function is in a tangent equation corresponding to the preset brightness.
In a third aspect, an embodiment of the present invention provides a display device, including: the pixel compensation device provided by the embodiment of the invention.
The invention has the following beneficial effects:
in the embodiment of the invention, the pixel corresponding to the dimming area not less than the preset brightness is determined as the first pixel and the pixel corresponding to the dimming area less than the preset brightness is determined as the second pixel according to the corresponding position relationship between each pixel and each dimming area, then the gray scale of the first pixel is compensated according to the first preset brightness gray scale function, and the gray scale of the second pixel is compensated according to the second preset brightness gray scale function, so that the second pixel corresponding to the dimming area with low brightness and other pixels (such as the first pixel) are compensated in different modes, the problems of dark noise amplification and overcompensation caused by the same compensation mode of each pixel in the prior art are avoided, and the display contrast is improved, the display effect is improved.
In the embodiment of the present invention, there is a certain relationship between the first preset luminance gray-scale function and the second preset luminance gray-scale function, that is, the second preset luminance gray-scale function is: the first preset brightness gray scale function is in a tangent equation corresponding to the preset brightness, that is, the second preset brightness gray scale function is not set randomly but set according to the first preset brightness gray scale function, so that when the second pixel is compensated, the compensated effect can reflect the picture corresponding to the dark area more truly, and good transition is provided between the pictures corresponding to the non-dark area, so that the whole display picture is more delicate and natural, and the display effect is greatly improved.
Drawings
FIG. 1 is a schematic diagram of a prior art LCD;
FIG. 2 is a schematic structural diagram of a backlight module in the prior art;
FIG. 3 is a diagram illustrating the effect of pixel compensation in the prior art;
FIG. 4 is a flowchart illustrating a pixel compensation method according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating the effect of pixel compensation according to an embodiment of the present invention;
FIG. 6 is a schematic diagram illustrating a relationship between a first predetermined luminance gray-scale function and a second predetermined luminance gray-scale function according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of a pixel compensation device according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a display device according to an embodiment of the present invention.
Detailed Description
Specific embodiments of a pixel compensation method, a pixel compensation device and a display device according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
To illustrate, in the embodiment of the present invention, the duty ratio of the brightness of the dimming region may be understood as: the ratio of the current brightness of the dimming area to the brightness of the dimming area reaching the maximum value can also be understood as the brightness ratio of the dimming area, and therefore, the duty ratio of the brightness of the dimming area and the brightness ratio of the dimming area represent the same meaning and can be used interchangeably.
The inventor finds out in research that, as shown in fig. 1, the liquid crystal display includes: as shown in the structural schematic diagram of the backlight module 20 shown in fig. 2, the backlight module 20 may include a light-emitting substrate 21, a plurality of light-emitting elements (e.g., LEDs) 22 arranged in an array are disposed on the light-emitting substrate 21, the light-emitting elements 22 on the light-emitting substrate 21 are divided into regions to obtain a plurality of dimming regions 23, and the light-emitting luminances of different dimming regions 23 may be independently controlled according to a picture to be displayed.
Of course, the light adjusting regions 23 may be set to have different sizes, as shown in fig. 2, the sizes of the light adjusting regions 23 may be the same, and the setting is not limited herein and may be performed according to actual needs.
Moreover, the liquid crystal display panel can perform certain brightness compensation on each pixel according to the brightness of different dimming areas in the backlight module so as to ensure the final display brightness.
When performing brightness compensation on each pixel, a linear compensation method can be generally adopted, and the specific compensation principle is as follows:
assuming that all the light emitting elements in the light emitting substrate in the backlight module are turned on and the Local Dimming areas are not dimmed, this situation can be understood as that the LD (Local Dimming) algorithm is turned off, and at this time, the display brightness of the liquid crystal display perceived by human eyes is the first brightness, which is denoted by Lv _ off.
Assuming that the LD algorithm is turned on when performing the local dimming on each dimming area in the backlight module, the display brightness of the liquid crystal display sensed by human eyes is the second brightness, which is denoted by Lv _ on.
Wherein, Gray _ off and Gray _ on respectively represent Gray levels displayed on the corresponding liquid crystal display panel before and after each dimming area in the backlight module performs local dimming, and PWM _ off and PWM _ on respectively represent duty ratios of the brightness of the corresponding dimming area when the LD algorithm is turned off and on.
If the bit width of 8-bit pixel is taken as an example, but not limited to this, according to the pixel compensation principle, the display brightness of the lcd perceived by human eyes before and after the LD algorithm is turned OFF and ON should be the same, so Lv _ OFF is Lv _ ON, that is:
PWM_off×(Gray_off/255)K＝PWM_on×(Gray_on/255)K；
in general, PWM _ off may be 100%, and in this case, the gray level compensation formula of the pixel can be obtained as follows:
Gray_on＝[1/(PWM_on)1/K]×Gray_off；
therefore, the smaller the PWM _ on, i.e. the smaller the duty ratio of the brightness of the dimming area, the larger the gray scale compensation coefficient, wherein K is expressed as described below, and a specific gray scale compensation coefficient curve is shown in fig. 3, where the abscissa represents the duty ratio of the brightness of the dimming area and the ordinate represents the gray scale compensation coefficient.
As the duty ratio is smaller, the brightness of the dimming area is smaller, that is, the corresponding dimming area is a dark area, so as shown in fig. 3, it can be known that the gray scale compensation coefficient of the dark area is larger, and thus, originally low-brightness noise which is not easy to perceive is easily amplified, an overcompensation phenomenon occurs, which causes a reduction in display contrast and a reduction in display effect.
Based on this, in order to improve the display contrast and improve the display effect, the embodiment of the invention provides a pixel compensation method.
Specifically, the pixel compensation method provided by the embodiment of the invention is applied to a liquid crystal display device, the liquid crystal display device includes a display panel and a backlight module, the display panel is located on a light emitting surface of the backlight module, the display panel includes pixels arranged in an array, and the backlight module includes a plurality of light modulation regions, wherein a structural schematic diagram of the liquid crystal display device may be as shown in but not limited to fig. 1, and a structural schematic diagram of the backlight module may be as shown in but not limited to fig. 2, which is not described in detail herein.
Referring to fig. 4, the method may include:
s401, obtaining an image to be displayed, and determining the brightness of each dimming area according to the image to be displayed;
s402, according to the position corresponding relation between each pixel and each dimming area, determining a pixel corresponding to the dimming area not less than the preset brightness as a first pixel, determining a pixel corresponding to the dimming area less than the preset brightness as a second pixel, compensating the gray scale of the first pixel according to a first preset brightness gray scale function, and compensating the gray scale of the second pixel according to a second preset brightness gray scale function; the second preset luminance gray scale function may be: and a tangent equation corresponding to the preset brightness of the first preset brightness gray scale function.
In the embodiment of the present invention, by using the pixel compensation method, the second pixel corresponding to the dimming region with low brightness and other pixels (such as the first pixel) are compensated in different manners, so that the problems of dark-area noise amplification and overcompensation caused by performing compensation in the same compensation manner on each pixel in the prior art are solved, and meanwhile, the non-dark area can be ensured to have higher brightness, thereby improving the display contrast and improving the display effect.
For example, as shown in fig. 5, the diagram labeled (a) shows an effect diagram before pixel compensation, the diagram labeled (b) shows an effect diagram after compensation by using a pixel compensation method in the prior art, and the diagram labeled (c) shows an effect diagram after compensation by using a pixel compensation method provided by an embodiment of the present invention.
It is obvious that after the pixel compensation method in the prior art is adopted for compensation, the dark area has larger noise, wherein, as shown in (b) in fig. 5, the brighter content displayed in the area indicated by the dashed line box can be regarded as noise, i.e. low-brightness noise which is not easy to be perceived originally is displayed. After the pixel compensation method provided by the embodiment of the invention is adopted for compensation, a bright area has higher brightness, and dark area amplification noise can be avoided, namely, noise in a dotted line frame in (c) in fig. 5 is eliminated, so that the brightness in the dotted line frame is darker, a displayed image has higher contrast, and an excellent display effect is achieved.
In the embodiment of the present invention, there is a certain relationship between the first preset luminance gray-scale function and the second preset luminance gray-scale function, that is, the second preset luminance gray-scale function is: the first preset brightness gray scale function is in a tangent equation corresponding to the preset brightness, that is, the second preset brightness gray scale function is not set randomly but set according to the first preset brightness gray scale function, so that when the second pixel is compensated, the compensated effect can reflect the picture corresponding to the dark area more truly, and good transition is provided between the pictures corresponding to the non-dark area, so that the whole display picture is more delicate and natural, and the display effect is greatly improved.
Optionally, in the embodiment of the present invention, the first preset luminance grayscale function may represent a power function corresponding relationship between the luminance of the dimming region and the grayscale compensation coefficient of the pixel corresponding to the dimming region;
the second preset brightness gray scale function can represent the linear relation between the brightness of the dimming area and the gray scale compensation coefficient of the pixel corresponding to the dimming area.
For example, as shown in fig. 6, a schematic diagram of a relationship between a first preset luminance gray-scale function and a second preset luminance gray-scale function, a solid line 1 represents the first preset luminance gray-scale function, a solid line 2 represents the second preset luminance gray-scale function, and the solid line 2 is a tangent of a curve shown in the solid line 1 at a point X0.
The ordinate represents a gray scale compensation coefficient of the pixel, the abscissa represents a duty ratio of the brightness of the dimming area, the smaller the numerical value of the abscissa, the smaller the duty ratio of the brightness of the dimming area, that is, the darker the brightness of the dimming area, the dark area is represented, and the larger the numerical value of the abscissa, the larger the duty ratio of the brightness of the dimming area is, that is, the brighter the brightness of the dimming area, the bright area is represented. As shown in fig. 6, a dimming region corresponding to a dimming region having a luminance duty ratio smaller than X0 may be referred to as a dark region, and a dimming region corresponding to a dimming region having a luminance duty ratio greater than or equal to X0 may be referred to as a bright region.
The larger the value of the ordinate is, the larger the gray scale compensation coefficient representing the pixel is, and the smaller the value of the ordinate is, the smaller the gray scale compensation coefficient representing the pixel is.
Therefore, as shown in fig. 6, when the pixels corresponding to the dark area are compensated by the solid line 2, the compensation coefficient is small, and the noise of the dark area can be suppressed; when the pixels corresponding to the brightness are compensated by using the solid line 1, it can be ensured that the bright area has higher brightness.
Therefore, amplification of noise in a dark area can be effectively avoided, and meanwhile, the bright area can be kept to have higher brightness, so that the displayed image has higher contrast, and the display effect is greatly improved.
Optionally, in order to compensate the gray scale of the first pixel, in an embodiment of the present invention, the compensating the gray scale of the first pixel according to a first preset luminance gray scale function specifically includes:
determining a gray scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the first pixel according to the following formula:
Y1＝X1 -1/K，X1∈[X0,1]；
X1＝L1/L0；
wherein, Y1A gray scale compensation coefficient, X, corresponding to the brightness of the dimming region corresponding to the first pixel1Indicating the brightness ratio, L, of the dimming area corresponding to the first pixel1Indicating the brightness L of the dimming region corresponding to the first pixel obtained after the dimming region is adjusted according to the image to be displayed by adopting a preset local dimming algorithm0Denotes the maximum luminance in each dimming region when no region dimming is performed, X0The ratio of the preset brightness to the maximum brightness of each dimming area when the dimming area is not subjected to regional dimming is represented, and K represents a constant;
and performing product operation on the gray scale of the first pixel and the determined gray scale compensation coefficient to obtain the gray scale compensated by the first pixel.
In this case, the meaning of K may be understood as a value of gamma voltage, and a relationship between gray scale and brightness indicated by the gamma voltage may be set according to needs and display requirements of the display panel in an actual situation, which is not limited herein.
For example, it is assumed that the backlight module includes 3 dimming regions, which are respectively numbered as dimming region 1, dimming region 2, and dimming region 3, and the description is only given by taking the example of including 3 dimming regions, but in actual cases, the backlight module includes a plurality of dimming regions, which is not limited to 3.
Assuming that the luminance ratio of the dimming area 1 is 0.05, the luminance ratio of the dimming area 2 is 0.3, and the luminance ratio of the dimming area 3 is 0.7, if X0 is set to be 0.24, then the luminance ratio of the dimming area 1 is less than X0, and the luminance ratios of the dimming area 2 and the dimming area 3 are both greater than X0, at this time:
the pixels corresponding to the dimming area 2 are determined as first pixels, and the gray scale compensation coefficient of each first pixel corresponding to the dimming area 2 is as follows: y is1＝0.3-1/KAnd the formula corresponds to the solid line 1, the corresponding gray-scale compensation coefficient Y can be read from the solid line 1 shown in FIG. 61About 1.8.
The pixels corresponding to the dimming area 3 are determined as first pixels, and the gray scale compensation coefficient of each first pixel corresponding to the dimming area 3 is as follows: y is1＝0.71/KAnd the formula corresponds to the solid line 1, the corresponding gray-scale compensation coefficient Y can be read from the solid line 1 shown in FIG. 61About 1.3.
And finally, multiplying the gray scale of each first pixel corresponding to the light adjusting area 2 by 1.8 to obtain a compensated gray scale, and multiplying the gray scale of each first pixel corresponding to the light adjusting area 3 by 1.3 to obtain a compensated gray scale.
Optionally, in order to compensate the gray scale of the second pixel, in an embodiment of the present invention, the compensating the gray scale of the second pixel according to a second preset luminance gray scale function specifically includes:
determining a gray scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the second pixel according to the following formula:
Y2＝a×X2+b，X2∈(0,X0)；
X2＝L2/L0；
a＝(-1/K)×X0 -(1/K+1)；
b＝Y0+1/K×X0 -1/K；
wherein, Y2Representing a second pair of pixelsGray scale compensation coefficient, X, corresponding to the brightness of the dimming area2Indicating the brightness ratio, L, of the dimming region corresponding to the second pixel2A brightness value L representing the brightness value obtained after the dimming region corresponding to the second pixel is subjected to regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0Denotes the maximum brightness value, X, of each dimming region when no region dimming is performed0Denotes the ratio of the preset brightness to the maximum brightness of each dimming region without regional dimming, Y0Representing the sum of X determined according to a first predetermined luminance gray-scale function0The corresponding value, K, represents a constant.
And performing product operation on the gray scale of the second pixel and the determined gray scale compensation coefficient to obtain the compensated gray scale of the second pixel.
For example, it is still assumed that the backlight module includes 3 dimming regions, which are respectively numbered as dimming region 1, dimming region 2, and dimming region 3. Similarly, assuming that the luminance ratio of dimming region 1 is 0.05, the luminance ratio of dimming region 2 is 0.3, and the luminance ratio of dimming region 3 is 0.7, if X0 is set to 0.24, then the luminance ratio of dimming region 1 is less than X0, and the luminance ratios of dimming region 2 and dimming region 3 are both greater than X0, at this time:
the pixels corresponding to the dimming area 1 are determined as second pixels, and the gray scale compensation coefficient of each second pixel corresponding to the dimming area 1 is as follows: y is2A × 0.05+ b, and the formula corresponds to the solid line 2, the gray-scale compensation coefficient corresponding to 0.05 can be read out from the solid line 2 shown in fig. 6 to be about 2.6.
And finally, multiplying the gray scale of each second pixel corresponding to the dimming area 1 by 2.6 to obtain the compensated gray scale.
Alternatively, in the embodiment of the present invention, the preset brightness may be determined according to the brightness of the dimming area and the gray scale of each pixel.
This is due to:
on one hand, the LD algorithm may determine the backlight brightness of each dimming region according to the display content of the corresponding pixel of the dimming region, and since the dimming regions are not completely isolated, the backlight brightness of a single dimming region may be affected by the backlight diffusion of the peripheral dimming regions. For a certain pixel corresponding to the dimming region, the backlight brightness of the dimming region where the pixel is located is theoretically the effect of diffusion and superposition of the backlight of each dimming region. Therefore, when the LD algorithm is used for pixel compensation, the influence of the backlight diffusion needs to be considered, and a preset algorithm (which may be any algorithm capable of accurately estimating the brightness, but is not limited herein) is used to estimate the backlight brightness of the dimming area where a certain pixel is located, and the accuracy of the estimation directly affects the effect of pixel compensation.
According to the theoretical compensation curve (as shown in a solid line 1 in fig. 6), the lower the duty ratio of the luminance of the dimming area where the pixel is located, the larger the slope thereof, the more sensitive to the luminance change, and if the backlight luminance estimation of the dimming area with the smaller duty ratio of the luminance is slightly inaccurate, the larger deviation of the compensation coefficient occurs, which causes the overcompensation problem.
Therefore, the duty ratio X0 of the brightness corresponding to the preset brightness is selected depending on the accuracy of the backlight brightness estimation of the dimming area where the pixel is located, and should satisfy: when the duty ratio of the brightness is larger than X0, the accuracy of backlight brightness estimation is high, and the influence on the compensation coefficient is small.
On the other hand, in order to improve the display contrast, it is necessary that the luminance of the pixel corresponding to the dark region (which may be understood as a dimming region having a small luminance) is small, the luminance of the pixel corresponding to the bright region (which may be understood as a dimming region having a large luminance) is large, and the luminance of the pixel is positively correlated with the gray scale.
In practical applications, the preset brightness may be selected according to actual needs, and is not limited herein, as long as the display contrast can be improved and the display effect can be improved.
Based on the same inventive concept, embodiments of the present invention provide a pixel compensation apparatus, and a specific implementation principle of the apparatus is similar to that of the aforementioned pixel compensation method, and reference may be made to the foregoing method for specific embodiments of the apparatus, and repeated details are not repeated.
Specifically, the pixel compensation device provided by the embodiment of the invention is applied to a liquid crystal display device, the liquid crystal display device comprises a display panel and a backlight module, the display panel is located on a light-emitting surface of the backlight module, the display panel comprises pixels arranged in an array manner, and the backlight module comprises a plurality of light modulation areas; as shown in fig. 7, the pixel compensation device may include:
a first unit 701, configured to obtain an image to be displayed, and determine brightness of each dimming area according to the image to be displayed;
a second unit 702, configured to determine, according to a position correspondence between each pixel and each dimming region, a pixel corresponding to a dimming region not less than a preset brightness as a first pixel, determine a pixel corresponding to a dimming region less than the preset brightness as a second pixel, compensate a gray scale of the first pixel according to a first preset brightness gray scale function, and compensate a gray scale of the second pixel according to a second preset brightness gray scale function;
wherein the second preset luminance gray scale function is: and a tangent equation corresponding to the preset brightness of the first preset brightness gray scale function.
Optionally, the first preset brightness gray scale function represents a power function corresponding relation between the brightness of the dimming area and the gray scale compensation coefficient of the pixel corresponding to the dimming area;
the second preset brightness gray scale function represents the linear relation between the brightness of the dimming area and the gray scale compensation coefficient of the corresponding pixel of the dimming area.
Optionally, the second unit 702 is specifically configured to:
determining a gray scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the first pixel according to the following formula:
Y1＝X1 -1/K，X1∈[X0,1]；
X1＝L1/L0；
wherein, Y1A gray scale compensation coefficient, X, corresponding to the brightness of the dimming region corresponding to the first pixel1Indicating the brightness ratio, L, of the dimming area corresponding to the first pixel1Indicating tone corresponding to the first pixelThe brightness L of the light region is obtained after the light region is subjected to regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0Denotes the maximum luminance in each dimming region when no region dimming is performed, X0The ratio of the preset brightness to the maximum brightness of each dimming area when the dimming area is not subjected to regional dimming is represented, and K represents a constant;
and performing product operation on the gray scale of the first pixel and the determined gray scale compensation coefficient to obtain the gray scale compensated by the first pixel.
Optionally, the second unit 702 is specifically configured to:
determining a gray scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the second pixel according to the following formula:
Y2＝a×X2+b，X2∈(0,X0)；
X2＝L2/L0；
a＝(-1/K)×X0 -(1/K+1)；
b＝Y0+1/K×X0 -1/K；
wherein, Y2A gray scale compensation coefficient, X, corresponding to the brightness of the dimming region corresponding to the second pixel2Indicating the brightness ratio, L, of the dimming region corresponding to the second pixel2A brightness value L representing the brightness value obtained after the dimming region corresponding to the second pixel is subjected to regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0Denotes the maximum brightness value, X, of each dimming region when no region dimming is performed0Denotes the ratio of the preset brightness to the maximum brightness of each dimming region without regional dimming, Y0Representing the sum of X determined according to a first predetermined luminance gray-scale function0The corresponding value, K, represents a constant.
And performing product operation on the gray scale of the second pixel and the determined gray scale compensation coefficient to obtain the compensated gray scale of the second pixel.
Based on the same inventive concept, an embodiment of the present invention provides a display device, as shown in fig. 8, which may include: the pixel compensation device provided by the embodiment of the invention.
In a specific implementation, the display device may be: any product or component with a display function, such as a mobile phone (as shown in fig. 8), a tablet computer, a television, a display, a notebook computer, a digital photo frame, and a navigator. The implementation of the display device can refer to the above embodiments of the pixel compensation device, and repeated descriptions are omitted.
Furthermore, it should be noted that, optionally, the display device provided in the embodiment of the present invention may also be a special display, such as an instrument panel, and is applied to vehicle-mounted display, that is, the pixel compensation method provided in the embodiment of the present invention may be used to compensate the display screen of the special display, so as to improve the display effect of the special display, implement application of the special display in a special field, expand the application field, and expand the application range.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. The pixel compensation method is characterized by being applied to a liquid crystal display device, wherein the liquid crystal display device comprises a display panel and a backlight module, the display panel is positioned on a light emergent surface of the backlight module, the display panel comprises pixels which are arranged in an array mode, and the backlight module comprises a plurality of light modulation areas; the method comprises the following steps:
acquiring an image to be displayed, and determining the brightness of each light adjusting area according to the image to be displayed;
according to the position corresponding relation between each pixel and each dimming area, determining the pixel corresponding to the dimming area with the brightness not less than the preset brightness as a first pixel, determining the pixel corresponding to the dimming area with the brightness less than the preset brightness as a second pixel, compensating the gray scale of the first pixel according to a first preset brightness gray scale function, and compensating the gray scale of the second pixel according to a second preset brightness gray scale function;
wherein the second preset luminance grayscale function is: a tangent equation corresponding to the first preset brightness gray scale function at the preset brightness; the first preset brightness gray scale function represents the power function corresponding relation between the brightness of the dimming area and the gray scale compensation coefficient of the pixel corresponding to the dimming area; the second preset brightness gray scale function represents the linear relation between the brightness of the dimming area and the gray scale compensation coefficient of the pixel corresponding to the dimming area;
and in the range that the brightness of the dimming area is smaller than the brightness of the dimming area corresponding to the tangent point of the second preset brightness gray scale function and the first preset brightness gray scale function, the gray scale compensation coefficient corresponding to the second preset brightness gray scale function is smaller than the first preset brightness gray scale function.
2. The method of claim 1, wherein compensating for the gray level of the first pixel according to a first predetermined luminance gray level function comprises:
determining a gray-scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the first pixel according to the following formula:
Y1＝X1 -1/K，X1∈[X0,1]；
X1＝L1/L0；
wherein, Y1A gray scale compensation coefficient, X, representing the brightness of the dimming area corresponding to the first pixel1Representing a luminance ratio, L, of the dimming area corresponding to the first pixel1Indicating the brightness L of the dimming area corresponding to the first pixel obtained after performing regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0X represents the maximum brightness of each dimming region when no region dimming is performed0Expressing the ratio of the preset brightness to the maximum brightness of each dimming area when no area dimming is carried out, wherein K represents a constant;
and performing product operation on the gray scale of the first pixel and the determined gray scale compensation coefficient to obtain the compensated gray scale of the first pixel.
3. The method of claim 1, wherein compensating for the gray level of the second pixel according to a second predetermined luminance gray level function comprises:
determining a gray-scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the second pixel according to the following formula:
Y2＝a×X2+b，X2∈(0,X0)；
X2＝L2/L0；
a＝(-1/K)×X0 -(1/K+1)；
b＝Y0+1/K×X0 -1/K；
wherein, Y2A gray scale compensation coefficient, X, representing the brightness of the dimming area corresponding to the second pixel2Representing a luminance ratio, L, of the dimming area corresponding to the second pixel2A brightness value L representing a brightness value obtained after the dimming area corresponding to the second pixel performs regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0Represents the maximum brightness value X of each dimming region when no region dimming is performed0A ratio, Y, of the preset brightness to the maximum brightness of each of the dimming regions when no region dimming is performed0Representing the sum of X determined according to the first preset brightness gray scale function0Corresponding values, K representing a constant;
and performing product operation on the gray scale of the second pixel and the determined gray scale compensation coefficient to obtain the compensated gray scale of the second pixel.
4. The method according to any one of claims 1 to 3, wherein the preset luminance is determined based on a luminance of the dimming area and a gray scale of each of the pixels.
5. A pixel compensation device is applied to a liquid crystal display device, the liquid crystal display device comprises a display panel and a backlight module, the display panel is positioned on a light-emitting surface of the backlight module, the display panel comprises pixels which are arranged in an array mode, and the backlight module comprises a plurality of light modulation areas; the pixel compensation device includes:
the first unit is used for acquiring an image to be displayed and determining the brightness of each dimming area according to the image to be displayed;
the second unit is used for determining the pixels corresponding to the dimming areas not smaller than the preset brightness as first pixels and determining the pixels corresponding to the dimming areas smaller than the preset brightness as second pixels according to the position corresponding relation between each pixel and each dimming area, compensating the gray scale of the first pixels according to a first preset brightness gray scale function, and compensating the gray scale of the second pixels according to a second preset brightness gray scale function;
wherein the second preset luminance grayscale function is: a tangent equation corresponding to the first preset brightness gray scale function at the preset brightness; the first preset brightness gray scale function represents the power function corresponding relation between the brightness of the dimming area and the gray scale compensation coefficient of the pixel corresponding to the dimming area; the second preset brightness gray scale function represents the linear relation between the brightness of the dimming area and the gray scale compensation coefficient of the pixel corresponding to the dimming area;
and in the range that the brightness of the dimming area is smaller than the brightness of the dimming area corresponding to the tangent point of the second preset brightness gray scale function and the first preset brightness gray scale function, the gray scale compensation coefficient corresponding to the second preset brightness gray scale function is smaller than the first preset brightness gray scale function.
6. The apparatus of claim 5, wherein the second unit is specifically configured to:
determining a gray-scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the first pixel according to the following formula:
Y1＝X1 -1/K，X1∈[X0,1]；
X1＝L1/L0；
wherein, Y1A gray scale compensation coefficient, X, representing the brightness of the dimming area corresponding to the first pixel1Representing a luminance ratio, L, of the dimming area corresponding to the first pixel1Indicating the brightness L of the dimming area corresponding to the first pixel obtained after performing regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0X represents the maximum brightness of each dimming region when no region dimming is performed0Expressing the ratio of the preset brightness to the maximum brightness of each dimming area when no area dimming is carried out, wherein K represents a constant;
and performing product operation on the gray scale of the first pixel and the determined gray scale compensation coefficient to obtain the compensated gray scale of the first pixel.
7. The apparatus of claim 5, wherein the second unit is specifically configured to:
determining a gray-scale compensation coefficient corresponding to the brightness of the dimming area corresponding to the second pixel according to the following formula:
Y2＝a×X2+b，X2∈(0,X0)；
X2＝L2/L0；
a＝(-1/K)×X0 -(1/K+1)；
b＝Y0+1/K×X0 -1/K；
wherein, Y2A gray scale compensation coefficient, X, representing the brightness of the dimming area corresponding to the second pixel2Representing a luminance ratio, L, of the dimming area corresponding to the second pixel2A brightness value L representing a brightness value obtained after the dimming area corresponding to the second pixel performs regional dimming according to the image to be displayed by adopting a preset regional dimming algorithm0Represents the maximum brightness value X of each dimming region when no region dimming is performed0Representing the preset brightness and each light adjusting areaRatio of maximum luminance when area dimming is not performed, Y0Representing the sum of X determined according to the first preset brightness gray scale function0Corresponding values, K representing a constant;
and performing product operation on the gray scale of the second pixel and the determined gray scale compensation coefficient to obtain the compensated gray scale of the second pixel.
8. A display device, comprising: a pixel compensation arrangement as claimed in any one of claims 5 to 7.
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