CN102025952B - Brightness correction method and system for display device - Google Patents

Abstract

The invention relates to the technical field of display devices, in particular to brightness correction method and system for a display device. In the method, (1) brightness correction is carried out on more than one brightness sensor; (2) in the normal operation of the display device, the brightness values of the brightness sensors after brightness correction are used as the brightness value of pixel points corresponding to the brightness sensors; (3) brightness collecting interpolation is carried out on pixel points without the arrangement of the brightness sensors to obtain the brightness values corresponding to the pixel points; and (4) local brightness compensating factor calculation and brightness compensation are carried out to each pixel point. The brightness correction method and the brightness correction system have the characteristics of clear structure and simple calculation and are easy to realize, and when a single-screen brightness is corrected, the brightness compensation calculation is carried out by taking a small screen as a unit, therefore, the minimum compression of the brightness values of all the pixel points is avoided and the brightness loss is effectively reduced.

Description

A kind of display unit brightness correcting method and system thereof

Technical field

The present invention relates to the display device technology field, particularly a kind of display unit brightness correcting method and system thereof.

Background technology

The projection splicing system all is widely used at aspects such as business meetings, advertising, Industry Control, traffic monitorings; Growing field is to large-screen display equipment and technology requirement also rapid growth; But, in the splicing system use, usually run into a difficult problem: how to realize piecing together wall brightness and color uniformity.Brightness and color homogeneity just become an important parameter weighing projection splice displaying system quality quality.

The projection combination is made up of single projection display unit, and the central area brightness of the single projection display unit of prior art is greater than fringe region, i.e. the dark angle of the dark side of screen phenomenon.

Summary of the invention

First goal of the invention of the present invention is to provide a kind of display unit brightness correcting method, with the central area brightness that solves single projection display unit in the prior art greater than fringe region, i.e. the technical problem of the dark angle of the dark side of screen phenomenon.

In order to realize first goal of the invention of the present invention, the technical scheme of employing is following:

A kind of display unit brightness correcting method; Display unit is provided with the central processing unit that a plurality of one-tenth ranks are arranged; Each central processing unit is handled one or more luminance sensors; The resulting brightness of the luminance sensor more than according on display unit, being provided with is carried out luminance compensation to display unit, and said method also comprises:

(1) to carrying out gamma correction more than a luminance sensor;

(2) carry out gamma correction after, according to luminance sensor through the brightness value of the brightness value behind the gamma correction as luminance sensor institute corresponding pixel points;

(3) brightness value that obtains according to step (2) carries out brightness to the pixel that luminance sensor is not set and gathers the brightness value that interpolation obtains corresponding pixel points;

(4) brightness value that obtains according to step (2) and step (3) carries out the local luminance penalty coefficient to each pixel and calculates;

(5) each pixel carries out luminance compensation according to the luminance compensation coefficient, and the brightness value of each pixel multiply by the brightness value after obtaining proofreading and correct behind the luminance compensation coefficient respectively.

As a kind of preferred version, said method comprises:

(21) carry out red gamma correction, the display unit output red, execution in step (1)～(4) obtain the red luminance compensation coefficient of each pixel;

(22) carry out green gamma correction, display unit output is green, and execution in step (1)～(4) obtain the green luminance compensation coefficient of each pixel;

(23) carry out blue gamma correction, the display unit output blue, execution in step (1)～(4) obtain the blue luminance compensation coefficient of each pixel;

After executing red gamma correction, green gamma correction and blue gamma correction, execution in step (5);

The brightness of said step (5) replenishes and comprises: each pixel is carried out following operation:

The red brightness after red luminance compensation coefficient obtains proofreading and correct is multiply by in the red brightness of each pixel;

The green brightness after green luminance compensation coefficient obtains proofreading and correct is multiply by in the green brightness of each pixel;

The blue brightness after blue luminance compensation coefficient obtains proofreading and correct is multiply by in the blue brightness of each pixel.

As further preferred version, said step (1) comprising:

Each transducer is carried out following gamma correction:

(31) control display unit output;

(32) measure the illuminance value E of the test point in the transducer investigative range of transducer through the illuminance measurement device _Ei, and write down the output frequency F of transducer simultaneously _i

(33) change the brightness output of display unit, and repeated execution of steps (31), up to reaching preset brightness correcting measuring times N, execution in step (34) then;

(34) according to N illuminance value E _EiWith N output frequency F _i, obtain E through least square fitting _Ei=kF _i+ f _oIn coefficient k and coefficient f _o

Said step (2) comprising: revise below the output valve of each transducer is done and obtain brightness value f:

f＝kF _i+f _O。

As further preferred version, said step (3) comprising:

With display unit lower left corner end points is that initial point is made the cartesian coordinate axes with x axle and y axle; Transducer is not set and is not in for each and go together or the first pixel a of same column with any transducer; And said first kind pixel a does not exceed the transducer investigative range, carries out following interpolation operation:

The coordinate of each first kind pixel a is (x _a, y _a), an a left and above and with the coordinate of the nearest transducer a1 of an a be (x _1a, y _1a), the brightness value that obtains according to step (2) is f _1aAt an a right-hand and above and with the coordinate of the nearest transducer a2 of an a be (x _2a, y _1a), the brightness value that obtains according to step (2) is f _2aAn a left and below and with the coordinate of the nearest transducer a3 of an a be (x _1a, y _2a), the brightness value that obtains according to step (2) is f _3aAt an a right-hand and below and with the coordinate of the nearest transducer a4 of an a be (x _2a, y _2a), the brightness value that obtains according to step (2) is f _4a

Concrete steps are following:

(41) the x direction of principal axis at each first kind pixel a carries out interpolation calculation, according to following formula obtain each first kind pixel a directly over the point brightness value f (a "):

$f\left(a^{\′\′}\right)=\frac{x_{2a}-x_a}{x_{2a}-x_{1a}}\·f_{1a}+\frac{x_a-x_{1a}}{x_{2a}-x_{1a}}\·f_{2a},$

The brightness value f of point under each first kind pixel a (a '):

$f\left(a^{\′}\right)=\frac{x_{2a}-x_a}{x_{2a}-x_{1a}}\·f_{3a}+\frac{x_a-x_{1a}}{x_{2a}-x_{1a}}\·f_{4a}$

(42) according to f (a ") and f (a ') carries out interpolation calculation at the y direction of principal axis of each first kind pixel a, obtains the brightness value f (a) of each first kind pixel a according to following formula:

$f\left(a\right)=\frac{y_{2a}-y_a}{y_{2a}-y_{1a}}\·f\left(a^{\′\′}\right)+\frac{y_a-y_{1a}}{y_{2a}-y_{1a}}\·f\left(a^{\′}\right).$

As further preferred version, said step (3) comprising:

With display unit lower left corner end points is that initial point is made and had x axle and y axle cartesian coordinate axes; For each transducer is not set but is in second type of pixel b of same row with any transducer; And said second type of pixel b do not exceed the transducer investigative range, operation below carrying out:

The coordinate of each second type of pixel b is (x _b, y _b), above a b and with the coordinate of the nearest transducer b1 of a b be (x _1b, y _1b), the brightness value that obtains according to step (2) is f _1bBelow a b and with the coordinate of the nearest transducer b2 of a b be (x _1b, y _2b), the brightness value that obtains according to step (2) is f _2b

Y direction of principal axis to each second type of pixel b carries out interpolation calculation, obtains the brightness value f (b) of each second type of pixel b according to following formula

$f\left(b\right)=\frac{y_{2b}-y_b}{y_{2b}-y_{1b}}\·f_{1b}+\frac{y_b-y_{1b}}{y_{2b}-y_{1b}}\·f_{2b}.$

As further preferred version, said step (3) comprising:

With display unit lower left corner end points is that initial point is made and had x axle and y axle cartesian coordinate axes; For each transducer is not set but is in the 3rd type of pixel c with delegation with any transducer; And said the 3rd type of pixel c do not exceed the transducer investigative range, operation below carrying out:

The coordinate of each the 3rd type of pixel c is (x _c, y _c), a c left and with the coordinate of the nearest transducer c1 of a c be (x _1c, y _1c), the brightness value that obtains according to step (2) is f _1cAt a c right-hand and with the coordinate of the nearest transducer c2 of a c be (x _1c, y _2c), the brightness value that obtains according to step (2) is f _2c

X direction of principal axis to each the 3rd type of pixel c carries out interpolation calculation, obtains the brightness value f (c) of each the 3rd type of pixel c according to following formula

$f\left(c\right)=\frac{x_{2c}-x_c}{x_{2c}-x_{1c}}\·f_{1c}+\frac{x_c-x_{1c}}{x_{2c}-x_{1c}}\·f_{2c}.$

As further preferred version, said step (3) comprising:

Exceed the 4th type of pixel d of transducer investigative range for each, operation below carrying out:

Seek and each the 4th type of first sensor that pixel d is nearest, second transducer and the 3rd transducer;

The distance of first sensor and the 4th type of pixel d is L ₁, the distance of second transducer and the 4th type of pixel d is L ₂, the distance of the 3rd transducer and the 4th type of pixel d is L ₃, the brightness value that first sensor obtains according to step (2) is Y1, and the brightness value that second transducer obtains according to step (2) is Y2, and the 3rd transducer is Y3 according to the brightness value that step (2) obtains, and makes L=L ₁+ L ₂+ L ₃:

If L ₁＞L ₂＞L ₃, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3,$

If L ₁=L ₂, and Y1＞Y2, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;Y_2+\left(\frac{L_2}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_1}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3,$

If L ₁=L ₂, and Y1＜Y2, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3,$

If L ₂=L ₃, and Y2＞Y3, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3+\left(\frac{L_1}{L}\right)\&CenterDot;Y_2,$

If L ₂=L ₃, and Y2＜Y3, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3.$

The area that detector can cover on the transducer mounting panel is less than display screen; Shown in Figure of description 6; The quadrangle of forming with the first row high order end, low order end transducer and transducer last column high order end, four transducers of low order end on the transducer mounting panel is the scope that detector can detect; The pixel that exceeds on this tetragonal display screen is the scope that detector can not detect, and promptly exceeds the transducer investigative range.

As further preferred version, said step (4) comprising:

Display unit is divided into M zone; With central processing unit and handled transducer thereof as a zone; The local luminance penalty coefficient is carried out in each zone to be calculated; Said zone is a rectangle; The line position that the handled the top of each central processing unit luminance sensor is detected is each regional widthwise edge boundary line, top; The handled below of each central processing unit line position that luminance sensor detected is each regional widthwise edge boundary line, bottom, and the column position that the handled left luminance sensor of each central processing unit is detected is each regional left end longitudinal boundary line, and the handled column position that the most right-hand luminance sensor detected of each central processing unit is each regional right-hand member longitudinal boundary line;

For the first row central processing unit of display unit, its widthwise edge boundary line, regional top expands to first row of display unit pixel;

For the central processing unit of last column of display unit, its widthwise edge boundary line, regional bottom expands to last column of display unit pixel;

For the first row central processing unit of display unit, its regional left end longitudinal boundary line expands to first row of display unit pixel;

For last row central processing unit that shows display unit, its regional right-hand member longitudinal boundary line expands to last row of display unit pixel;

Concrete luminance compensation coefficient calculations method is following:

4) calculated for each region the average pixel intensity

and throughout all the pixels of the display device brightness average

5) search brightness minimum value in each zone;

6) each is regional average brightness

is done comparison, zoning luminance compensation coefficient g with the average brightness

of whole screen:

If a)

Make each pixel luminance compensation coefficient

L _MinThe brightness minimum value of all pixels in the expression i zone, L _SelfThe brightness value of each pixel self in the expression i zone;

B) if

The brightness value L that compares each pixel in the i zone _iWith the average brightness in the i zone

If

Make g=1; Otherwise, if

Order

Second goal of the invention of the present invention is to provide a kind of display unit gamma correction system, with the bearing calibration that realizes that first goal of the invention of the present invention is proposed.

In order to realize second goal of the invention of the present invention, the technical scheme of employing is following:

A kind of display unit gamma correction system, said system comprises:

On display unit, be provided with the central processing unit that a plurality of one-tenth ranks are arranged; Each central processing unit is handled one or more luminance sensors, and said system also comprises gamma correction module, luminance acquisition module, brightness interpolating module and the luminance compensation module that connects successively:

The gamma correction module is used for carrying out gamma correction more than a luminance sensor;

The luminance acquisition module is normally in service in display unit, obtains according to luminance sensor through the brightness value of the brightness value behind the gamma correction as luminance sensor institute corresponding pixel points;

The brightness value that the brightness interpolating module is obtained according to the luminance acquisition module carries out brightness to the pixel that luminance sensor is not set and gathers the brightness value that interpolation obtains corresponding pixel points;

The brightness value that the luminance compensation module is obtained according to luminance acquisition module and brightness interpolating module carries out the luminance compensation coefficient calculations to each pixel, and according to the luminance compensation coefficient each pixel is carried out luminance compensation.

The present invention has clear in structure, calculates characteristics simple, that be easy to realize.Coupling system has provided a complete method that solves combination list screen irregularity in brightness; When proofreading and correct the brightness of list screen; Arrangement by MCU on the transducer mounting panel is divided into a plurality of " the small screen " with Dan Ping; With " the small screen " is that unit carries out luminance compensation calculating, has avoided the brightness value of all pixels is carried out minimal compression, has effectively reduced the luminance loss.

Description of drawings

Fig. 1 is a brightness acquisition system sketch map;

Fig. 2 is the working sensor principle schematic;

Fig. 3 gathers human-computer interaction interface for projecting apparatus brightness;

Fig. 4 is the bilinearity brightness interpolating sketch map of different capable heterotaxy point a;

Fig. 5 is the bilinearity brightness interpolating sketch map of colleague or same column point b, c;

Fig. 6 is that the sensor region on the mounting panel is divided figure.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment the present invention is done further detailed explanation.

The embodiment of the invention has designed the mounting panel that luminance sensor is housed in order to gather the brightness value of display, and is as shown in Figure 1.9 * 12 MCU (being central processing unit) are arranged on the transducer mounting panel, 9 transducers are arranged on each MCU.MCU is of a size of: 93 * 93mm, be spaced apart 6mm between MCU and the MCU, and be spaced apart 33mm between last each transducer of MCU, the distance between transducer and the MCU edge is 13.5mm.

Control projecting apparatus movement; On projecting apparatus screen, show red, green, blue respectively; Obtain after the brightness of each pixel on the display screen penalty coefficient Gr, Gg, the Gb of each pixel press the calculating of method in literary composition different colours respectively to three kinds of colors of red, green, blue under.The penalty coefficient programming is embedded in the projecting apparatus movement, and movement will be done product rgb value afterwards with penalty coefficient separately respectively with the rgb value of original pixel point automatically and remove display image as new pixel point value.

Utilize the transducer mounting panel that the display brightness value is proofreaied and correct and mainly be divided into three steps: interpolation is gathered in sensor calibration, brightness, the local luminance penalty coefficient calculates.

One: sensor calibration

The transducer of selecting for use is a luminance sensor, and when light stimulus shone on the transducer, transducer is with regard to frequency values of corresponding output, and was as shown in Figure 2.Illuminance is different, and output frequency value is just different.Satisfy linear relationship: E between transducer output frequency value and the illuminance value _Ei=kF _i+ f _o(F wherein _iBe transducer output frequency, E _EiThe illuminance that receives for transducer).And for different sensor, the linear relationship between output frequency and the illuminance is different.The purpose of sensor calibration is exactly: the k, the f that confirm each transducer _oValue.When the illumination of projecting apparatus is mapped on the transducer, can calculate the illuminance value of projecting apparatus according to the transducer output frequency value.

The brightness value of control projecting apparatus is chosen 20 points in the projecting apparatus brightness range, measure the corresponding brightness value of selected brightness value respectively with illuminance meter, and programming calculates 20 corresponding with it frequency values.So just obtain 20 groups of data: (F ₁, E _E1), (F ₂, E _E2) ... (F ₂₀, E _E20).Obtain through least square fitting then:

E _ei＝kF _i+f _o (1)

108 transducers are all done above-mentioned processing, so just realized correction different sensors.The tester tests for ease, has designed human-computer interaction interface to a MCU, and is as shown in Figure 3.

1) on a MCU 9 transducers are arranged, it is numbered 1-9, drop-down menu can be selected sensor number, following brightness, illumination, frequency, k value, f _oBe worth corresponding with selected transducer.

2) the brightness drop-down menu can be controlled the brightness of projecting apparatus.

3) 20 brightness value data record, can be used as constant and directly store, and click the brightness value drop-down menu and select brightness value.Annotate: the brightness value that has recorded is corresponding one by one with selected brightness value.

4) choose brightness value after, " calculating " button of click frequency, MCU calculate 9 transducers each self-corresponding output frequency value under current brightness value, and feed back to the PC storage; " demonstration " button of click frequency shows current transducer of choosing and illumination corresponding sensor output frequency value.

5) after 20 frequency values tests finish, show the best k, the f that satisfy sensor light illumination and output frequency relational expression _oValue, and send MCU to.

Two: interpolation is gathered in brightness

Can find out that from transducer mounting panel sketch map (as shown in Figure 1) this plate can not collect the brightness value of each pixel on the display screen, this just need be to the pixel brightness value that do not collect interpolation calculation just.

When carrying out brightness interpolating, according to the distributing position of interpolation point: in the transducer investigative range with the transducer investigative range outside, adopt different interpolation methods.In the transducer investigative range, select for use bilinear interpolation method that the brightness value of projecting apparatus is carried out interpolation calculation,, limited by peripheral transducer number, then select for use distance weighted interpolation method to carry out brightness interpolating for the point that exceeds the transducer investigative range.

1) bilinear interpolation in the transducer investigative range

A) when interpolation point and sensor measurement are put different row or heterotaxy

Point a requires the brightness value of invocation point a for putting the brightness interpolating impact point of different row or heterotaxy with sensor measurement, needs to carry out interpolation at directions X earlier and obtains a directly over a " point with under the brightness value of a ' point (two points and sensor acquisition point with delegation on).Suppose that (x, four y) nearest transducer actual measured value are respectively f from left to right, from top to bottom with putting a ₁, f ₂, f ₃, f ₄, the pixel position from left to right, be respectively from top to bottom: (x ₁, y ₁), (x ₂, y ₁), (x ₁, y ₂), (x ₂, y ₂), as shown in Figure 4.

Then put the brightness value f that puts directly over a (a ") is:

$f\left(a^{\&prime;\&prime;}\right)=\frac{x_2-x}{x_2-x_1}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1+\frac{x-x_1}{x_2-x_1}\&CenterDot;f_2---\left(2\right)$

The brightness value f that puts under the some a (a ') is:

$f\left(a^{\&prime;}\right)=\frac{x_2-x}{x_2-x_1}\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">f</figure-callout>}}_3+\frac{x-x_1}{x_2-x_1}\&CenterDot;f_4---\left(3\right)$

Secondly carry out interpolation in the y direction, the brightness value f (a) that obtains an a is:

$f\left(a\right)=\frac{y_2-y}{y_2-{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}\&CenterDot;f\left(a^{\&prime;\&prime;}\right)+\frac{y-y_1}{y_2-{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}\&CenterDot;f(a\text{'})---\left(4\right)$

B) when interpolation point and sensor measurement point same column or when going together

Point b, c is respectively and sensor measurement point same column, the brightness interpolating impact point of going together.Its bilinearity brightness interpolating sketch map is as shown in Figure 5:

For a b, directly carry out y axle interpolation, obtain the brightness value f (b) that b orders and be:

$f\left(b\right)=\frac{y_2-y}{y_2-{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1+\frac{y-y_1}{y_2-{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}\&CenterDot;f_3---\left(5\right)$

For a c, directly carry out X axle interpolation, obtain the brightness value f (c) that c orders and be:

$f\left(c\right)=\frac{x_2-x}{x_2-x_1}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1+\frac{x-x_1}{x_2-x_1}\&CenterDot;f_2---\left(6\right)$

2) the outer distance weighted interpolation of transducer investigative range

For the point that exceeds the transducer investigative range, seek and 3 nearest sensor acquisition points of interpolation point, then the brightness value of target interpolation point is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;Y_3---\left(7\right)$

Wherein, L ₁Ultimate range between expression target interpolation point and the sensor acquisition point, L ₂Inferior big, L ₃Minimum; L=L ₁+ L ₂+ L ₃Sensor acquisition to the brightness value of three points be respectively: Y ₁, Y ₂, Y ₃, Y wherein ₁Be the corresponding brightness value of distance objective interpolation point sensor acquisition point farthest, Y ₂Be the distance objective interpolation point time corresponding brightness value of sensor acquisition point far away, Y ₃Be the nearest corresponding brightness value of sensor acquisition point of distance objective interpolation point.When distance equates, make the contribution degree of the big collection point of brightness value big; If brightness value equates that also two distance orderings that then equate can be in no particular order.

If L ₁=L ₂, and Y1＜Y2, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3,$

If L ₂=L ₃, and Y2＞Y3, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3+\left(\frac{L_1}{L}\right)\&CenterDot;Y_2,$

If L ₂=L ₃, and Y2＜Y3, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HSA00000355428900011.png,HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HSA00000355428900022.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3.$

Three: the local luminance penalty coefficient calculates

Obtained after the brightness value of each pixel pixel to be carried out pointwise correction, also need seek the penalty coefficient of each pixel.When algorithm for design, should be noted that:

1) need consider the penalty coefficient of R, G, three kinds of colors of B respectively; Control projecting apparatus movement; On projecting apparatus screen, show red, green, blue respectively; Obtain through step mentioned above after the brightness of each pixel on the display screen, respectively to the penalty coefficient of each pixel under three kinds of color calculation different colours of red, green, blue, can obtain Gr, Gg, Gb again;

2) when carrying out pointwise correction, the R of each pixel, G, B penalty coefficient all can not be greater than 1.

Below narration is an example with the redness, and other two kinds of colors adopt same procedure.

Transducer mounting panel sketch map is as shown in Figure 1.9 * 12 MCU are arranged on the mounting panel, 9 transducers are arranged on each MCU, that is: 9 row, 12 row MCU are arranged on the transducer mounting panel, 3 row, 3 biographies sensors are arranged on each MCU.Display screen is divided into 9 * 12 zonules, as being one " the small screen ", carries out pointwise correction then to each piece zone.

Convenient when carrying out area dividing for describing, first talk about boundary line, territory, the area pellucida division methods of (comprising horizontal and vertical), shown in Fig. 6 dotted line.Adjacent two laterally are four summits in every zone with four intersection points of adjacent two longitudinal boundary lines, confirmed that the summit can draw every zone scope separately.

Widthwise edge boundary line: the widthwise edge boundary line on the first behavior top of display picture element point; The line position that detects of the third line transducer of the first row MCU is second this line sensor sensing point of row of boundary line next line of being expert at the third line as the boundary line; The line position that the third line transducer of the second row MCU detects is the fourth line of boundary line; Equally; The fifth line of next behavior boundary line that this line sensor sensing point is expert at, by that analogy, last column of display picture element point is the widthwise edge boundary line of low side.

Longitudinal boundary line: in like manner; First of display picture element point is classified the high order end of longitudinal boundary line as; The column position that the 3rd biographies sensor of the first row MCU detects is the secondary series of boundary line, and next of these biographies sensor sensing point place row classified the 3rd row of boundary line as, and the column position that the 3rd biographies sensor of secondary series MCU detects is the 4th row of boundary line; By that analogy, last of display picture element point classified the low order end of longitudinal boundary line as.

Four intersection points of adjacent two row and adjacent two row boundary lines are the summit of zonule, so just display screen are divided into 9 * 12 zonules, and the branch situation is carried out pointwise correction then, and concrete grammar is following:

A) calculate the average brightness of each cell in the domain

and the brightness of the entire screen average

2) search brightness minimum value in each zonule;

3) the average luminance of each small region and the average brightness of the entire screen

compare:

If a)

Order

L _MinThe brightness minimum value of all pixels in the expression i zone, L _SelfThe brightness value of each pixel self in the expression i zone;

B) if The brightness value L that compares each pixel in the i zone _iWith the average brightness in the i zone

If

Make Gr=1; Otherwise, if

Order

Obtain after the Gr value of each pixel of All Ranges, it is made tables of data, convey to signal processing module, realize the brightness pointwise correction.With regard to having avoided the brightness value of all pixels is carried out minimal compression like this.

Above-mentioned Gr is merely red luminance compensation coefficient, can calculate green and blue penalty coefficient Gg and Gb according to aforesaid way.

As stated, can realize preferably that just the present invention, the foregoing description are merely preferred embodiment of the present invention, be not to be used for limiting practical range of the present invention; Be that all equalizations of doing according to content of the present invention change and modification, all contained by claim of the present invention scope required for protection.

Claims (9)

1. display unit brightness correcting method; Display unit is provided with the central processing unit that a plurality of one-tenth ranks are arranged; Each central processing unit is handled one or more luminance sensors; The resulting brightness of the luminance sensor more than according on display unit, being provided with is carried out luminance compensation to display unit, it is characterized in that said method also comprises:

(1) to carrying out gamma correction more than a luminance sensor;

(2) carry out gamma correction after, according to luminance sensor through the brightness value of the brightness value behind the gamma correction as luminance sensor institute corresponding pixel points;

(3) brightness value that obtains according to step (2) carries out brightness to the pixel that luminance sensor is not set and gathers the brightness value that interpolation obtains corresponding pixel points;

(4) brightness value that obtains according to step (2) and step (3) carries out the local luminance penalty coefficient to each pixel and calculates;

(5) each pixel carries out luminance compensation according to the luminance compensation coefficient, and the brightness value of each pixel multiply by the brightness value after obtaining proofreading and correct behind the luminance compensation coefficient respectively.

2. bearing calibration according to claim 1 is characterized in that, said method comprises:

(21) carry out red gamma correction, the display unit output red, execution in step (1)～(4) obtain the red luminance compensation coefficient of each pixel;

(22) carry out green gamma correction, display unit output is green, and execution in step (1)～(4) obtain the green luminance compensation coefficient of each pixel;

(23) carry out blue gamma correction, the display unit output blue, execution in step (1)～(4) obtain the blue luminance compensation coefficient of each pixel;

After executing red gamma correction, green gamma correction and blue gamma correction, execution in step (5);

The luminance compensation of said step (5) comprising: each pixel is carried out following operation:

The red brightness after red luminance compensation coefficient obtains proofreading and correct is multiply by in the red brightness of each pixel;

The green brightness after green luminance compensation coefficient obtains proofreading and correct is multiply by in the green brightness of each pixel;

The blue brightness after blue luminance compensation coefficient obtains proofreading and correct is multiply by in the blue brightness of each pixel.

3. bearing calibration according to claim 1 and 2 is characterized in that, said step (1) comprising:

Each transducer is carried out following gamma correction:

(31) control display unit output;

(32) measure the illuminance value E of the test point in the transducer investigative range through the illuminance measurement device _Ei, and write down the output frequency F of transducer simultaneously _i

(33) change the brightness output of display unit, and repeated execution of steps (31), up to reaching preset brightness correcting measuring times N, execution in step (34) then;

(34) according to N illuminance value E _EiWith N output frequency F _i, obtain E through least square fitting _Ei=kF _i+ f _oIn coefficient k and coefficient f _o

Said step (2) comprising: revise below the output valve of each transducer is done and obtain brightness value f:

f＝kF _i+f ₀。

4. bearing calibration according to claim 1 and 2 is characterized in that, said step (3) comprising:

With display unit lower left corner end points is that initial point is made the cartesian coordinate axes with x axle and y axle; Transducer is not set and is not in for each and go together or the first kind pixel a of same column with any transducer; And said first kind pixel a does not exceed the transducer investigative range, carries out following interpolation operation:

The coordinate of each first kind pixel a is (x _a, y _a), an a left and above and with the coordinate of the nearest transducer a1 of an a be (x _1a, y _1a), the brightness value that obtains according to step (2) is f _1aAt an a right-hand and above and with the coordinate of the nearest transducer a2 of an a be (x _2a, y _1a), the brightness value that obtains according to step (2) is f _2aAn a left and below and with the coordinate of the nearest transducer a3 of an a be (x _1a, y _2a), the brightness value that obtains according to step (2) is f _3aAt an a right-hand and below and with the coordinate of the nearest transducer a4 of an a be (x _2a, y _2a), the brightness value that obtains according to step (2) is f _4a

Concrete steps are following:

(41) the x direction of principal axis at each first kind pixel a carries out interpolation calculation, according to following formula obtain each first kind pixel a directly over the point brightness value f (a "):

$f\left(a^{\&prime;\&prime;}\right)=\frac{x_{2a}-x_a}{x_{2a}-x_{1a}}\&CenterDot;f_{1a}+\frac{x_a-x_{1a}}{x_{2a}-x_{1a}}\&CenterDot;f_{2a},$

The brightness value f of point under each first kind pixel a (a '):

$f\left(a^{\&prime;}\right)=\frac{x_{2a}-x_a}{x_{2a}-x_{1a}}\&CenterDot;f_{3a}+\frac{x_a-x_{1a}}{x_{2a}-x_{1a}}\&CenterDot;f_{4a}$

(42) according to f (a ") and f (a ') carries out interpolation calculation at the y direction of principal axis of each first kind pixel a, obtains the brightness value f (a) of each first kind pixel a according to following formula:

$f\left(a\right)=\frac{y_{2a}-y_a}{y_{2a}-y_{1a}}\&CenterDot;f\left(a^{\&prime;\&prime;}\right)+\frac{y_a-y_{1a}}{y_{2a}-y_{1a}}\&CenterDot;f\left(a^{\&prime;}\right).$

5. bearing calibration according to claim 1 and 2 is characterized in that, said step (3) comprising:

With display unit lower left corner end points is that initial point is made and had x axle and y axle cartesian coordinate axes; For each transducer is not set but is in second type of pixel b of same row with any transducer; And said second type of pixel b do not exceed the transducer investigative range, operation below carrying out:

The coordinate of each second type of pixel b is (x _b, y _b), above a b and with the coordinate of the nearest transducer b1 of a b be (x _1b, y _1b), the brightness value that obtains according to step (2) is f _1bBelow a b and with the coordinate of the nearest transducer b2 of a b be (x _1b, y _2b), the brightness value that obtains according to step (2) is f _2b

Y direction of principal axis to each second type of pixel b carries out interpolation calculation, obtains the brightness value f (b) of each second type of pixel b according to following formula

$f\left(b\right)=\frac{y_{2b}-y_b}{y_{2b}-y_{1b}}\&CenterDot;f_{1b}+\frac{y_b-y_{1b}}{y_{2b}-y_{1b}}\&CenterDot;f_{2b}.$

6. bearing calibration according to claim 1 and 2 is characterized in that, said step (3) comprising:

With display unit lower left corner end points is that initial point is made and had x axle and y axle cartesian coordinate axes; For each transducer is not set but is in the 3rd type of pixel c with delegation with any transducer; And said the 3rd type of pixel c do not exceed the transducer investigative range, operation below carrying out:

The coordinate of each the 3rd type of pixel c is (x _c, y _c), a c left and with the coordinate of the nearest transducer c1 of a c be (x _1c, y _1c), the brightness value that obtains according to step (2) is f _1cAt a c right-hand and with the coordinate of the nearest transducer c2 of a c be (x _1c, y _2c), the brightness value that obtains according to step (2) is f _2c

X direction of principal axis to each the 3rd type of pixel c carries out interpolation calculation, obtains the brightness value f (c) of each the 3rd type of pixel c according to following formula

$f\left(c\right)=\frac{x_{2c}-x_c}{x_{2c}-x_{1c}}\&CenterDot;f_{1c}+\frac{x_c-x_{1c}}{x_{2c}-x_{1c}}\&CenterDot;f_{2c}.$

7. bearing calibration according to claim 1 is characterized in that, said step (3) comprising:

Exceed the 4th type of pixel d of transducer investigative range for each, operation below carrying out:

Seek and each the 4th type of first sensor that pixel d is nearest, second transducer and the 3rd transducer;

The distance of first sensor and the 4th type of pixel d is L ₁, the distance of second transducer and the 4th type of pixel d is L ₂, the distance of the 3rd transducer and the 4th type of pixel d is L ₃, the brightness value that first sensor obtains according to step (2) is Y1, and the brightness value that second transducer obtains according to step (2) is Y2, and the 3rd transducer is Y3 according to the brightness value that step (2) obtains, and makes L=L ₁+ L ₂+ L ₃:

If L ₁＞L ₂＞L ₃, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;Y_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;Y_3,$

If L ₁=L ₂, and Y1＞Y2, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;Y_2+\left(\frac{L_2}{L}\right)\&CenterDot;Y_1+\left(\frac{L_1}{L}\right)\&CenterDot;Y_3,$

If L ₁=L ₂, and Y1＜Y2, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;Y_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;Y_3,$

If L ₂=L ₃, and Y2＞Y3, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;Y_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_3+\left(\frac{L_1}{L}\right)\&CenterDot;Y_2,$

If L ₂=L ₃, and Y2＜Y3, then the brightness value Y of each the 4th type of pixel d is:

$Y=\left(\frac{L_3}{L}\right)\&CenterDot;Y_1+\left(\frac{L_2}{L}\right)\&CenterDot;Y_2+\left(\frac{L_1}{L}\right)\&CenterDot;Y_3.$

8. bearing calibration according to claim 1 is characterized in that, said step (4) comprising:

Display unit is divided into M zone; With central processing unit and handled transducer thereof as a zone; The local luminance penalty coefficient is carried out in each zone to be calculated; Said zone is a rectangle; The line position that the handled the top of each central processing unit luminance sensor is detected is each regional widthwise edge boundary line, top; The handled below of each central processing unit line position that luminance sensor detected is each regional widthwise edge boundary line, bottom, and the column position that the handled left luminance sensor of each central processing unit is detected is each regional left end longitudinal boundary line, and the handled column position that the most right-hand luminance sensor detected of each central processing unit is each regional right-hand member longitudinal boundary line;

For the first row central processing unit of display unit, its widthwise edge boundary line, regional top expands to first row of display unit pixel;

For the central processing unit of last column of display unit, its widthwise edge boundary line, regional bottom expands to last column of display unit pixel;

For the first row central processing unit of display unit, its regional left end longitudinal boundary line expands to first row of display unit pixel;

For last row central processing unit of display unit, its regional right-hand member longitudinal boundary line expands to last row of display unit pixel;

Concrete luminance compensation coefficient calculations method is following:

1) calculated for each region the average pixel intensity

and throughout all the pixels of the display device brightness average

2) search brightness minimum value in each zone;

3) each is regional average brightness

is done comparison, zoning luminance compensation coefficient g with the average brightness

of whole screen:

If a)

Make each pixel luminance compensation coefficient

L _MinThe brightness minimum value of all pixels in the expression i zone, L _SelfThe brightness value of each pixel self in the expression i zone;

B) if

The brightness value L that compares each pixel in the i zone _iWith the average brightness in the i zone

If $L_i<{\stackrel{\&OverBar;}{L}}_i,$ Make g=1; Otherwise, if $L_i\&GreaterEqual;{\stackrel{\&OverBar;}{L}}_i,$ Order $g=\frac{{\stackrel{\&OverBar;}{L}}_i}{L_i}.$

9. display unit gamma correction system is characterized in that said system comprises:

On display unit, be provided with the central processing unit that a plurality of one-tenth ranks are arranged; Each central processing unit is handled one or more luminance sensors, and said system also comprises gamma correction module, luminance acquisition module, brightness interpolating module and the luminance compensation module that connects successively:

The gamma correction module is used for carrying out gamma correction more than a luminance sensor;

The luminance acquisition module is normally in service in display unit, obtains according to luminance sensor through the brightness value of the brightness value behind the gamma correction as luminance sensor institute corresponding pixel points;

The brightness value that the brightness interpolating module is obtained according to the luminance acquisition module carries out brightness to the pixel that luminance sensor is not set and gathers the brightness value that interpolation obtains corresponding pixel points;

The brightness value that the luminance compensation module is obtained according to luminance acquisition module and brightness interpolating module carries out the luminance compensation coefficient calculations to each pixel, and according to the luminance compensation coefficient each pixel is carried out luminance compensation.

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