CN111243019A - Method for adjusting display content of liquid crystal display according to observation points - Google Patents

Abstract

The invention relates to a method for adjusting the display content of a liquid crystal display according to an observation point, which comprises two parts of image angle correction and brightness correction. And the image angle correction is to adjust the display angle of the image according to the obtained pose, so that the image can present the effect that two eyes are positioned on a straight line vertical to the central point of the display content. The relationship between the actual size of the screen for brightness correction and the number of pixels is calculated to be proportional to human eyes, and correction is performed according to the correction coefficient. The invention can ensure that an observer is not influenced by distortion, observe a normal effect, and correct the problem of unbalanced perceived brightness caused by different observation distances between different liquid crystal points and human eyes, thereby being not easy to generate dizzy feeling even if the observer observes for a long time.

Description

A method of adjusting the content displayed on the LCD screen according to the observation point

technical field

The invention relates to the field of liquid crystal screen display, in particular to a method and a liquid crystal screen for adjusting the display content of the liquid crystal screen according to the position of a long-term observation point of the human body, so that it can obtain a plane effect and balance brightness at the real observation point.

Background technique

LCD screen is a very important human-computer interaction device, which is almost ubiquitous in existing electronic products, and is an indispensable item in modern society.

When the LCD screen is observed, the ideal observation position is that the eyes are on a straight line perpendicular to the center point of the LCD screen. However, in some specific environments, the LCD screen is in a fixed position, and the user is often only one person, and the user's observation angle is always at a fixed angle and position, rather than the normal, most central point. best observation location and distance. In this case, the observer has always observed a distorted image, which affects the observation effect, and long-term observation is also prone to dizziness. In addition, because the positions of different liquid crystals of the LCD screen are closer to farther from the observer's eyes, the brightness perceived by the observation will also change from bright to dark, resulting in an imbalance.

If there is a method and a liquid crystal screen, which can adjust the original display of the liquid crystal screen on the premise of inputting the attitude (position, angle) of the observed value relative to the liquid crystal screen, so that it can present a view to the observer. The eyes are on a straight line perpendicular to the center point of the LCD screen for best results. Then, the observer can be prevented from being affected by the distortion, and the normal effect can be observed, and the long-term observation is not prone to dizziness. In addition, if the perceived brightness imbalance problem caused by different observation distances of different liquid crystal dots from the human eye can be corrected, the perception effect of the human eye will also be improved.

Existing technologies have not been able to meet the above requirements.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a set of adjusting the display content of the liquid crystal screen according to the position and posture of the long-term observation point of the human body on the basis of the existing electronic technology and machine vision technology, so that it can present the observer with a pair of eyes in a vertical direction. The best effect on a straight line at the center point of the LCD screen, even if the observer can obtain a flat effect and a method of balancing the brightness at his real observation point, and the LCD screen.

The method of adjusting the display content of the liquid crystal screen according to the observation point of the present invention includes two parts: image angle correction and brightness correction, wherein the image angle correction is to adjust the display angle of the image according to the obtained pose, so that it can show a pair of eyes in a vertical direction. The effect on the line showing the center point of the content. Brightness correction is that although the function of image angle correction can correct the angle of the image, etc., due to the distance between the different liquid crystal positions of the LCD screen and the observer's eyes, the brightness of the observation will also change from bright to dark. , resulting in an imbalance, so its brightness needs to be corrected. The modification method is to use the relationship between the real size of the screen and the number of pixels to calculate the proportional relationship with the human eye, and modify it according to the correction coefficient.

The specific steps of the method of the present invention are as follows:

1. Image angle correction

Step 1.1. Transform the angle of the user relative to the LCD screen obtained from the pose sensing device, take the center point of the LCD screen as the origin, take the X-Y-Z coordinates of the LCD screen as the original coordinate system 1, and the horizontal direction of the LCD screen coordinate system is the X-axis , The right direction is the positive direction; the vertical direction of the LCD screen coordinate system is the Y axis, and the downward direction is the positive direction; the vertical direction of the LCD screen coordinate system is the Z axis, and the far direction is the positive direction. The user's eyes are the offset coordinate system 2, the horizontal direction of the user's coordinate system is the X-axis, and the right direction is the positive direction; the vertical direction of the user's coordinate system is the Y-axis, and the downward direction is the positive direction; the user's coordinate system is vertical The sheet direction is the Z axis, and the far direction is the positive direction.

The offset angle of the offset coordinate system 2 relative to the original coordinate system 1 expressed using the X-Y-Z fixed-angle coordinate system (common knowledge in the field of robotics) is set as α, β, γ, and the spatial position of the user's eyes is relative to the original coordinate system. The coordinates of 1 are set as (lx, ly, lz), and the respective flip equations of the three fixed angles are calculated as Rz(α), Ry(β), Rx(γ):

The resulting flip equation for computing the three fixed angles is R:

The X-Y-Z fixed-angle coordinate system expression method involved in this step is a common expression content in machine vision, and the applicant will not repeat it here.

Step 1.2. The transformation matrix for calculating the spatial distance is H:

The transformation matrix for calculating the spatial distance is the inverse Hv of H. The matrix inversion is a common linear algebra problem, which will not be repeated here. The inv symbol represents the inversion.

Hv=inv(H)

Step 1.3. Set the original image as P1, then the image P2 after preliminary optimization is:

P2=Hv·P1

2. Brightness correction

2.1. Assume that the x-axis of the LCD screen has Mx liquid crystals and the y-axis has My liquid crystals, which is consistent with step 1.1. The coordinates of the spatial position of the user's eyes relative to the original coordinate system 1 are set to (lx, ly, lz).

Calculate the straight-line space distance between the human eye and the center point of the LCD screen:

Step 2.2. The correction formula for each liquid crystal point is:

where P2(i,j) is the result of steps 1-3, where i represents the i-th liquid crystal point on the x-axis, from 1 to Mx, where j represents the j-th liquid crystal point on the y-axis, starting from 1 ~My.

The sign of sgn() means to take the sign of the parameter, for example, sgn(7)=1, sgn(-0.1)=-1, sgn(0)=0; pa is the correction coefficient.

Step 3.3, use the P3(i,j) obtained in step 2.2 as the output and display it on the LCD screen.

The advantages of the present invention are that firstly, it can make the observer not affected by distortion and observe normal effects; secondly, it can correct the perceived brightness imbalance problem caused by different observation distances between different liquid crystal dots and the human eye; thirdly, long-term Observation is not easy to appear dizzy.

In the process of use, the present invention is matched with two devices of a liquid crystal screen and a position and attitude perception. The function of the LCD screen is to display information and realize human-computer interaction, and its function is to correct and display the displayed information according to the method of the present invention after obtaining the posture information of the posture sensing device. The function of pose perception is to obtain the pose of the long-term observation point of the human body, and transmit it to the CPU that comes with the LCD screen to correct the displayed information.

Description of drawings

1 is a schematic diagram of the structural relationship of an embodiment of the present invention;

2 is a schematic diagram of the relationship of three rotation angles in an embodiment of the present invention;

3 is a schematic diagram of a relational coordinate according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a pose-aware input device used in an embodiment of the present invention.

Detailed ways

The present invention will be further explained below with reference to FIG. 1 and FIG. 4 .

As shown in FIG. 1 , the function of the liquid crystal screen in the present invention is to display information and realize human-computer interaction. Its function is also to run the correction algorithm after obtaining the pose information of the pose perception device, so as to realize the correction of the displayed information and realize the main advantages proposed by the present invention. In this embodiment, the liquid crystal screen adopts a 32-inch LCD liquid crystal screen of Jiangsu Austin Optoelectronics Technology Co., Ltd., the CPU is open, and certain computing resources are also abundant.

Figure 1, 1 represents the LCD screen, 2 represents the pose perception device, 3 and 5 represent the observer angle with offset, 4 represents a reasonable pair of eyes on a straight line perpendicular to the center point of the LCD screen for the best effect upper position.

The function of the pose sensing device involved in the present invention is to obtain the pose of the long-term observation point of the human body, and transmit it to the CPU built in the LCD screen for further correction algorithm. It can be either a common Microsoft Kinect human body perception device, and data is provided by Kinect; it can also be based on rotation resistance, and the observer can adjust the input data by himself, as shown in Figure 4, which is the pose perception adopted in this embodiment. The simplest manual input version of the device, that is, the personnel use the knob switch to feel the adjustment by themselves. It has 1 group of switches and 6 groups of EC11 type 20K rotary resistors. The STM32F401 single-chip microcomputer is used to read the resistance values of the 6 groups of rotary resistors as the X-direction rotation. Angle γ, offset lx, Y-direction rotation angle β, offset ly, Z-direction rotation angle α, offset lx, output to the CPU that comes with the LCD screen, the function of a group of switches is to open and close the function of input parameters, That is, when it needs to be adjusted, output data to the LCD screen, and usually close this function.

As shown in FIG. 2 and FIG. 3 , the method for adjusting the display content of the liquid crystal screen according to the observation point of the present invention includes two parts: image angle correction and brightness correction, which are described as follows:

The content of the image angle correction is to adjust the display angle of the image according to the obtained pose, so that it can present an effect that the eyes are on a straight line perpendicular to the center point of the displayed content. The specific steps are:

Step 1-1, transform the angle of the user relative to the LCD screen obtained from the pose sensing device, take the center point of the LCD screen as the origin, take the X-Y-Z coordinates of the LCD screen as the original coordinate system 1, and the horizontal direction of the LCD screen coordinate system is The X axis and the right direction are positive; the vertical direction of the LCD screen coordinate system is the Y axis, and the downward direction is the positive direction; the vertical direction of the LCD screen coordinate system is the Z axis, and the far direction is the positive direction. The user's eyes are the offset coordinate system 2, the horizontal direction of the user's coordinate system is the X-axis, and the right direction is the positive direction; the vertical direction of the user's coordinate system is the Y-axis, and the downward direction is the positive direction; the user's coordinate system is vertical The sheet direction is the Z axis, and the far direction is the positive direction.

The offset angle of the offset coordinate system 2 relative to the original coordinate system 1 expressed using the X-Y-Z fixed-angle coordinate system (common knowledge in the field of robotics) is set as α, β, γ, and the spatial position of the user's eyes is relative to the original coordinate system. The coordinates of 1 are set as (lx, ly, lz), and the respective flip equations of the three fixed angles are calculated as Rz(α), Ry(β), Rx(γ):

The resulting flip equation for computing the three fixed angles is R:

Step 1-2, the transformation matrix for calculating the spatial distance is H:

The transformation matrix for calculating the spatial distance is the inverse Hv of H. The matrix inversion is a common linear algebra problem, which will not be repeated here. The inv symbol represents the inversion.

Hv=inv(H)

For example: Suppose the observer's eyes are parallel to the left border of the center point of the LCD screen, the X axis of the LCD screen is 1 meter, the Y axis is 0.8 meters, and the human eye is 0.5 meters away from the LCD screen. Then it can be seen that at this time, when the human eye observes the center point of the LCD screen, it rotates 45 degrees around the Y axis. That is, the synthesized flip equation R is only related to Y because the other XZ axes do not move at this moment:

At this moment, because the human eye is parallel to the left border of the LCD screen, the unit is millimeters, so lx=-500. Since it is parallel, ly=0. Because the human eye is 0.5 meters away from the LCD screen, so lz=500;

therefore

Then find the inverse of H:

Then, the corrected image can be calculated according to P2=Hv*P1, where P1 is the original digital image to be displayed.

Step 1-3, assuming the original image is P1, then the image P2 after preliminary optimization is:

P2=Hv·P1

The content of brightness correction is that although the function of image angle correction can correct the angle of the image, etc., due to the distance between the different liquid crystal positions of the LCD screen and the observer's eyes, the brightness of the observation will also be affected by the difference. The light becomes dark, resulting in an imbalance, so its brightness needs to be corrected.

The steps are to use the relationship between the real size of the screen and the number of pixels to calculate the proportional relationship with the human eye, and correct it according to the correction coefficient, as follows:

Step 2-1, suppose that the x-axis of the LCD screen has Mx liquid crystals, and the y-axis has My liquid crystals, which is consistent with step 1.1, and the coordinates of the spatial position of the user's eyes relative to the original coordinate system 1 are set to (lx, ly, lz ).

Calculate the straight-line space distance between the human eye and the center point of the LCD screen:

Step 2-2, the correction formula for each liquid crystal point is:

where P2(i,j) is the result of steps 1-3, where i represents the i-th liquid crystal point on the x-axis, from 1 to Mx, where j represents the j-th liquid crystal point on the y-axis, starting from 1 ~My.

Among them, the sign of sgn() means to take the sign of the parameter, for example, sgn(7)=1, sgn(-0.1)=-1, sgn(0)=0; pa is the correction coefficient.

In the embodiment of the present invention, a pixel value of 1000*800 is used, so Mx=1000, My=800. Both parameters pa and pb are set to 10, which means that the pixel value closest to the human eye is at most 255-10=245 brightness, and the farthest pixel value retains the original maximum brightness value of 255.

In step 2-3, the P3(i, j) obtained in step 2-2 is used as an output and displayed on the LCD screen.

For example: continue to use the above moment lx=-500, ly=0, ,lz=500, the LCD screen has Mx=1000, My=800;

By implementing the present invention, the original display of the liquid crystal screen can be adjusted on the premise of inputting the attitude (position, angle) of the observed value relative to the liquid crystal screen, so that it can present to the observer a pair of eyes that are perpendicular to the liquid crystal screen. The best effect is on a straight line from the center of the screen. It can make the observer not affected by distortion, observe the normal effect, and it is not easy to feel dizzy after long-term observation. In addition, the problem of perceived brightness imbalance caused by different observation distances of different liquid crystal dots from the human eye can be corrected, and the perception effect of the human eye can also be improved.

Claims (1)

1. A method for adjusting the display content of a liquid crystal display according to an observation point is characterized by comprising the following steps:

1) image angle correction

Step 1.1, changing the angle of a user relative to a liquid crystal screen, which is obtained from a pose sensing device, by taking the central point of the liquid crystal screen as an original point, taking X-Y-Z coordinates of the liquid crystal screen as an original coordinate system 1, and taking the transverse direction of the liquid crystal screen coordinate system as an X axis and the right direction as a forward direction; the vertical direction of the liquid crystal screen coordinate system is a Y axis, and the downward direction is a forward direction; the vertical direction of the liquid crystal screen coordinate system is a Z axis, and the far direction is a positive direction. The two eyes of the user are the coordinate system 2 after the deviation, the transverse direction of the coordinate system of the user is an X axis, and the right direction is a positive direction; the vertical direction of the user coordinate system is a Y axis, and the downward direction is a positive direction; the vertical sheet direction of the user coordinate system is a Z axis, and the far direction is a forward direction;

the deflection angles of the coordinate system 2 after the displacement expressed by the X-Y-Z fixed angle coordinate system relative to the original coordinate system 1 are set as α, β and gamma, the coordinates of the spatial positions of the two eyes of the user relative to the original coordinate system 1 are set as (lx, ly and lz), and the respective roll-over equations of the three fixed angles are calculated as Rz (α), Ry (β) and Rx (gamma):

the resulting flip equation for the three fixed angles is calculated as R:

step 1.2, calculating a transformation matrix of the spatial distance as H:

the transformation matrix for calculating the spatial distance is the inverse of H, Hv, with the inv sign representing the inversion.

Hv＝inv(H)

Step 1.3, setting the original image as P1, and then the image P2 after the preliminary optimization is:

P2＝Hv·P1

2) brightness correction

2.1, setting that the x axis of the liquid crystal screen has Mx liquid crystals, the y axis has My liquid crystals, and the step 1.1 is the same, and setting the spatial positions of the two eyes of the user as (lx, ly, lz) relative to the coordinates of the original coordinate system 1 at the moment;

calculating the linear space distance between the human eyes and the central point of the liquid crystal screen:

step 2.2, the correction formula of each liquid crystal point is as follows:

wherein P2(i, j) is the result of step 1-3, wherein i represents the ith LC dot for the x-axis from 1 to Mx, wherein j represents the jth LC dot for the y-axis from 1 to My;

the sign of sgn () means taking the sign of a parameter therein, for example, sgn (7) ═ 1, sgn (-0.1) ═ 1, sgn (0) ═ 0; pa is the correction factor;

and 3.3, displaying the P3(i, j) obtained in the step 2.2 on a liquid crystal screen as output.

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