TWI838031B - Smart display and brightness adjustment method thereof - Google Patents

Abstract

A smart display and a brightness adjustment method thereof are provided. A backlight brightness curve of the smart display is obtained. If the backlight brightness curve is a linear curve, then the backlight brightness curve is converted into an exponential curve. An image frame of the smart display is read. Whether the image frame adopts Standard Dynamic Range (SDR) display standard or adopts a High Dynamic Range (HDR) display standard is determined. If the image frame adopts the SDR display standard, a first gray scale brightness reduction procedure is executed. If the image frame adopts the HDR display standard, a second grayscale brightness reduction procedure is executed. The second grayscale brightness reduction procedure is different from the first grayscale brightness reduction procedure.

Description

Smart display and brightness adjustment method thereof

The present disclosure relates to a display and a control method thereof, and in particular to a smart display and a brightness adjustment method thereof.

Currently, monitors on the market can enable the High Dynamic Range (HDR) display standard through the operating system or graphics card. In the High Dynamic Range display standard, by adjusting the digital grayscale brightness or backlight brightness of the monitor screen, an extremely high contrast effect can be achieved.

With the introduction of OLED and Mini-LED panels in monitors, the brightness of monitors has been greatly improved. The high dynamic range display standard can reach a maximum peak brightness of more than 1000nits. If the user activates the high dynamic range display standard in a dim environment (such as below 100Lux), the human eye may feel uncomfortable and it is difficult to see the details in the picture. Long-term use may not only cause vision damage, but also consume a lot of monitor power.

This disclosure is about a smart display and a brightness adjustment method thereof, which converts a linear backlight brightness curve into an exponential backlight brightness curve to reduce the degree of brightness variation, thereby avoiding damage to human eyes in a dim environment. In addition, the smart display can use different methods to adjust the grayscale brightness of pixels for the standard dynamic range display standard and the high dynamic range display standard. In this way, the display effect of the standard dynamic range display standard or the high dynamic range display standard can be maintained, and the power saving effect can be achieved appropriately.

According to one aspect of the present disclosure, a brightness adjustment method for a smart display is proposed. The brightness adjustment method for a smart display includes the following steps. Obtain a backlight brightness curve of the smart display. If the backlight brightness curve is a linear curve, convert the backlight brightness curve into an exponential curve. Read an image screen of the smart display. Determine whether the image screen adopts a standard dynamic range (SDR) display standard or a high dynamic range (HDR) display standard. If the image screen adopts the standard dynamic range display standard, execute a first grayscale brightness reduction procedure. If the image screen adopts the high dynamic range display standard, execute a second grayscale brightness reduction procedure. The second grayscale brightness reduction procedure is different from the first grayscale brightness reduction procedure.

According to another aspect of the present disclosure, a smart display is provided. The smart display includes a backlight control unit, a conversion unit, a display standard determination unit, a first grayscale brightness reduction unit, and a second grayscale brightness reduction unit. The backlight control unit controls the backlight of the smart display according to a backlight brightness curve. If the backlight brightness curve is a linear curve, the conversion unit converts the backlight brightness curve into an exponential curve. The display standard determination unit is used to read an image frame of the smart display and determine whether the image frame adopts a standard dynamic range (SDR) display standard or a high dynamic range (HDR) display standard. If the image frame adopts the standard dynamic range display standard, the first grayscale brightness reduction unit executes a first grayscale brightness reduction procedure. If the image adopts the high dynamic range display standard, the second grayscale brightness reduction unit executes a second grayscale brightness reduction procedure. The second grayscale brightness reduction procedure is different from the first grayscale brightness reduction procedure.

In order to better understand the above and other aspects of this disclosure, the following is a specific example, and the attached drawings are used to explain in detail as follows:

100: Smart display

110: Display panel

120: Backlight control unit

130:Conversion unit

140: Imaging unit

160: Display standard judgment unit

170: First grayscale brightness reduction unit

180: Second grayscale brightness reduction unit

191: Image capture unit

192: Human eye detection unit

193: Ambient brightness detection unit

AL: Ambient brightness

avg: average grayscale brightness value

BRF: Adjustment level value

CV1, CV2: Backlight brightness curve

FM: Video screen

FM71: Human eye image

HDR: High Dynamic Range Display Standard

P50, P51, P52: points

P71: Center of human eye

PL: human eye gaze position

PR1: First gray level brightness reduction process

PR2: Second gray level brightness reduction process

ref: Adjust reference constant

RG: Human eye focus range

S1: Screen signal

S110,S120,S130,S140,S150,S170,S180,S1701,S1702,S1703,S1704,S1705,S1706,S1707,S1708,S1801,S1802,S1803,S1804,S1805,S1806,S1807,S1808,S1809,S1810,S1811,S1812: Steps

SDR: Standard Dynamic Range Display Standard

Figure 1 shows a backlight brightness curve of a smart display according to an embodiment.

FIG. 2 shows a block diagram of a smart display according to an embodiment.

Figure 3 shows a flow chart of a brightness adjustment method for a smart display according to an embodiment.

Figure 4 illustrates an example of the first gray level brightness reduction process.

Figure 5 illustrates another example of the first gray level brightness reduction process.

Figure 6 shows a detailed flow chart of step S170 according to an embodiment.

Figure 7 shows a detailed flow chart of step S180 according to an embodiment.

Please refer to Figure 1, which shows the backlight brightness curves CV1 and CV2 of the smart display 100 according to an embodiment. The smart display 100 can use a linear backlight brightness curve CV1 or an exponential backlight brightness curve CV2 to adjust the backlight. When the smart display 100 uses the standard dynamic range (SDR) to display the standard SDR, the backlight of the smart display 100 can be adjusted to 100% at most; when the smart display 100 uses the high dynamic range (HDR) to display the standard HDR, the backlight of the smart display 100 can be adjusted to 130% at most. The exponential backlight brightness curve CV2 can reduce the degree of brightness change to avoid damage to human eyes in a dim environment.

In addition, according to whether the smart display 100 currently adopts the standard dynamic range display standard SDR or the high dynamic range display standard HDR, the smart display 100 can adjust the grayscale brightness of the pixel in different ways. In this way, the display effect of the standard dynamic range display standard SDR or the high dynamic range display standard HDR can be maintained, and the power saving effect can be achieved appropriately.

Please refer to FIG. 2, which shows a block diagram of a smart display 100 according to an embodiment. The smart display 100 includes a display panel 110, a backlight control unit 120, a conversion unit 130, an imaging unit 140, a display standard determination unit 160, a first grayscale brightness reduction unit 170, a second grayscale brightness reduction unit 180, an image capture unit 191, a human eye detection unit 192, and an environment brightness detection unit 193. The display panel 110 is, for example, an OLED panel or an LCD panel using mini-LED. The backlight control unit 120 is used to perform backlight control. The conversion unit 130 is used to convert the backlight brightness curve CV1 and the backlight brightness curve CV2. The imaging unit 140 adjusts the grayscale brightness of various primary colors of each pixel according to a picture signal S1 so that these pixels form an image frame FM. The display standard determination unit 160 can read each pixel or intercept the picture signal S1 to read the content of the image frame FM and identify whether the standard dynamic range display standard SDR or the high dynamic range display standard HDR is currently adopted. The first grayscale brightness reduction unit 170 and the second grayscale brightness reduction unit 180 respectively perform different grayscale brightness reduction procedures for the standard dynamic range display standard SDR or the high dynamic range display standard HDR. The image capture unit 191 is used to capture the human eye picture FM71. The human eye detection unit 192 is used to detect the human eye. The ambient brightness detection unit 193 is used to detect ambient brightness. The backlight control unit 120, the conversion unit 130, the imaging unit 140, the display standard determination unit 160, the first grayscale brightness reduction unit 170, the second grayscale brightness reduction unit 180, the image capture unit 191 and the human eye detection unit 192 are, for example, a circuit, a chip, a circuit board, a computer program product, a program code, or a storage device for storing program codes. The ambient brightness detection unit 193 is, for example, a photosensitive resistor.

In this embodiment, the smart display 100 can convert the linear backlight brightness curve CV1 into an exponential backlight brightness curve CV2 through the backlight control unit 120 and the conversion unit 130 to reduce the degree of brightness change, thereby avoiding damage to human eyes in a dim environment. In addition, the smart display 100 can use the first grayscale brightness reduction unit 170 and the second grayscale brightness reduction unit 180 to adjust the grayscale brightness of pixels in different ways for the standard dynamic range display standard SDR and the high dynamic range display standard HDR. In this way, the display effect of the standard dynamic range display standard SDR or the high dynamic range display standard HDR can be maintained, and the power saving effect can also be achieved appropriately. The following is a flowchart to explain the operation of each component in detail.

Please refer to FIG. 3, which shows a flow chart of a brightness adjustment method of a smart display 100 according to an embodiment. In step S110, as shown in FIG. 1, a backlight brightness curve of the smart display 100 (for example, backlight brightness curve CV1 or backlight brightness curve CV2) is obtained.

Next, in step S120, as shown in FIG. 1 and FIG. 2, the conversion unit 130 determines whether the backlight brightness curve is a linear curve or an exponential curve. If the backlight brightness curve is a linear curve (such as the backlight brightness curve CV1), the process proceeds to step S130; if the backlight brightness curve is an exponential curve (such as the backlight brightness curve CV2), the process proceeds to step S150. Referring to the following formula (1), LCD BLCM _50% is the set brightness of the backlight control unit 120 for 50% brightness read by the conversion unit 130 (for example, point P51 on the backlight brightness curve CV1 of FIG. 1, whose set brightness is 115; or point P52 on the backlight brightness curve CV2 of FIG. 1, whose set brightness is 48). Linear BLCM _50% is the ideal linear brightness of 50% brightness (for example, point P50 on the dotted line in Figure 1, its ideal linear brightness is 127.5). Ratio _Backlight is the brightness ratio. If the brightness ratio is less than 2, it can be determined that the backlight brightness curve adopts a linear curve; if the brightness ratio is greater than or equal to 2, it can be determined that the backlight brightness curve adopts an exponential curve.

In step S130, as shown in FIG. 2, the conversion unit 130 converts the backlight brightness curve CV1 into an exponential curve (i.e., into the backlight brightness curve CV2). After the linear backlight brightness curve CV1 is converted into the exponential backlight brightness curve CV2, the degree of brightness change can be reduced to avoid damage to human eyes in a dim environment.

For example, the conversion unit 130 converts the linear backlight brightness curve CV1 into the exponential backlight brightness curve CV2 using the following equations (2) and (3).

為轉換後之背光亮度曲線CV2，LCD BLCM _0%為背光亮度曲線CV1之0%亮度，LCD BLCM _130%為背光亮度曲線CV1之130%亮度，Percentage _(0~130%)為背光亮度曲線CV2之百分比， K _(0~130)%為不同百分比之補償係數， Backlight _(0~130)%為百分比。 in

is the converted backlight brightness curve CV2, LCD BLCM _0% is the 0% brightness of the backlight brightness curve CV1, LCD BLCM _130% is the 130% brightness of the backlight brightness curve CV1, Percentage _(0~130%) is the percentage of the backlight brightness curve CV2, K _{( 0~130 )%} is the compensation coefficient of different percentages, Backlight _{( 0~130 )%} is the percentage.

Next, in step S140, as shown in FIG. 2, the display standard determination unit 160 reads the image frame FM of the smart display 100. The display standard determination unit 160 can read each pixel or capture the screen signal S1 to read the content of the image frame FM.

Then, in step S150, as shown in FIG. 2, the display standard determination unit 160 determines whether the image frame FM adopts the standard dynamic range display standard SDR or the high dynamic range display standard HDR. If the image frame FM adopts the standard dynamic range display standard SDR, the process proceeds to step S170; if the image frame FM adopts the high dynamic range display standard HDR, the process proceeds to step S180.

In step S170, as shown in FIG. 2, the first grayscale brightness reduction unit 170 performs a first grayscale brightness reduction procedure PR1 on the pixels of the display panel 110. Please refer to FIG. 4, which illustrates an example of the first grayscale brightness reduction procedure PR1. The human eye's eye gaze position PL is the center of the human eye gaze range RG. The first grayscale brightness reduction procedure PR1 is to radially reduce the grayscale brightness values of all pixels outside the human eye gaze range RG in the image frame FM with the human eye gaze range RG as the center (the grayscale brightness values of the pixels within the human eye gaze range RG are not reduced). If a monochrome image is taken as an example, the human eye gaze range RG is the brightest, and the peripheral pixels of the human eye gaze range RG will gradually reduce their originally set brightness toward the edge. However, if the image frame FM is not a monochrome image, the human eye's focus range RG may not necessarily be the brightest position.

Please refer to Figure 5, which illustrates another example of the first grayscale brightness reduction procedure PR1. When the human eye is focused on the left side of the image frame FM, the first grayscale brightness reduction procedure PR1 is also centered on the left-biased human eye focus range RG, and radially reduces the grayscale brightness values of all pixels outside the human eye focus range RG in the image frame FM (the grayscale brightness values of pixels within the human eye focus range RG are not reduced). If a monochrome image is taken as an example, the human eye focus range RG maintains the original set brightness and remains the brightest, and the peripheral pixels will gradually reduce their original set brightness toward the edge. However, if the image frame FM is not a monochrome image, the human eye focus range RG is not necessarily the brightest position.

In step S180, as shown in FIG. 2, the second grayscale brightness reduction unit 180 performs a second grayscale brightness reduction procedure PR2 on the pixels of the display panel 110. The second grayscale brightness reduction procedure PR2 is different from the first grayscale brightness reduction procedure PR1. The second grayscale brightness reduction procedure PR2 only reduces the grayscale brightness values of some pixels. The reduction method is, for example, radial reduction with the human eye gaze position PL as the center. For example, the second grayscale brightness reduction procedure PR2 only reduces the grayscale brightness values of pixels whose grayscale brightness values are less than or equal to the average grayscale brightness value, and the grayscale brightness values of some pixels within the human eye gaze range RG are also reduced to maintain the display effect of the high dynamic range display standard.

The first grayscale brightness reduction procedure PR1 and the second grayscale brightness reduction procedure PR2 are further described in detail below.

Please refer to FIG. 6, which shows a detailed flow chart of step S170 according to an embodiment. In step S1701, as shown in FIG. 2, a human eye picture FM71 is captured by the image capture unit 191.

Next, in step S1702, as shown in FIG2, the human eye detection unit 192 obtains a human eye center position P71 based on the human eye image FM71. The human eye center position P71 is the midpoint of the line connecting the two eyes.

Then, in step S1703, as shown in FIG. 2, the eye detection unit 192 converts the eye center position P71 of the eye picture FM71 into the eye gaze position PL of the image picture FM. The eye detection unit 192 converts the eye center position P71 into the eye gaze position PL according to a two-dimensional coordinate conversion function, for example.

For example, the human eye detection unit 192 converts the human eye center position P71 into the human eye gaze position PL using the following formula (4).

( x _current ,y _current )=μ( x _eye ,y _eye )......................................................(4)

Where x _current is the X coordinate of the eye gaze position PL, y _current is the Y coordinate of the eye gaze position PL, x _eye is the X coordinate of the eye center position P71, y _eye is the X coordinate of the eye center position P71, and μ( , ) is the conversion function.

Next, in step S1704, as shown in FIG. 2, the eye detection unit 192 obtains the eye gaze range RG according to the eye gaze position PL. The eye gaze range RG is, for example, a range of 300 pixels * 400 pixels. The eye gaze position PL is located at the center of the eye gaze range RG, so the eye gaze range RG can be obtained by expanding 150 pixels upward and downward from the eye gaze position PL, and expanding 200 pixels to the left and right from the eye gaze position PL. For example, the four vertices of the eye gaze range RG are ( x _current -200, y _current +150), ( x _current +200, y _current +150), ( x _current -200, y _current -150), ( x _current +200, y _current -150).

Then, in step S1705, as shown in FIG. 2, the ambient brightness detection unit 193 detects an ambient brightness AL.

Next, in step S1706, as shown in FIG. 2, the first grayscale brightness reduction unit 170 obtains the adjustment reference constant ref according to the ambient brightness AL. The adjustment reference constant ref is proportional to the ambient brightness AL. For example, the first grayscale brightness reduction unit 170 obtains the adjustment reference constant ref by the following formula (5).

Wherein, SDR ( Ref ) _{BL & AL} is the adjustment reference constant ref under the standard dynamic range display standard SDR, AL ( Lux ) is the ambient brightness AL. Default L _Max ( nits ) is the maximum brightness, which is, for example, 600nits under the standard dynamic range display standard SDR. Sceen resolution ( milli ) is the screen resolution, for example, 1920× ^10-3 ×1080× ^10-3 , and Pi is a constant, for example, 3.1416.

Then, in step S1707, the first grayscale brightness reduction unit 170 obtains an adjustment level value BRF according to the distance between each pixel and the human eye gaze position PL. Each adjustment level value BRF is proportional to the distance between each pixel and the human eye gaze position PL. For example, the first grayscale brightness reduction unit 170 obtains the adjustment level value BRF by the following formula (6).

為各個像素與人眼注視位置PL的距離。 Among them, BRF ( Brightness Factor ) _{( x,y )} is the adjustment value BRF, SDR ( Ref ) _{BL & AL} is the adjustment value BRF,

is the distance between each pixel and the human eye's gaze position PL.

Next, in step S1708, as shown in FIG. 2, the first grayscale brightness reduction unit 170 reduces the grayscale brightness values of all pixels outside the human eye's attention range RG in the image frame FM with each adjustment degree value BRF. The first grayscale brightness reduction unit 170 reduces the grayscale brightness values, for example, according to the following equations (9) and (10).

( R _out ,G _out ,B _out ) _{( x =-960 to 960 ,y =-540 to 540)} =( R _in - R _in * BRF _{( x,y )} ,G _in - G _in * BRF _{( x,y )} ,B _in - B _in * BRF _{( x,y )} )..............(9)

( R _out ,G _out ,B _out ) _{( x =-200 to 200 ,y =-150 to 150)} =( R _in ,G _in ,B _in ) _{( x,y )} ...................................................................(10)

Among them, ( R _out , G _out , B _out ) is the grayscale brightness value of the red/green/blue primary colors after downgrading, R _in is the red grayscale brightness value before adjustment, G _in is the green grayscale brightness value before adjustment, B _in is the blue grayscale brightness value before adjustment, and BRF _{( x, y )} is the adjustment degree value BRF.

The above formula (9) adjusts all pixels, while the above formula (10) adjusts the pixels within the human eye's gaze range RG back to the original set brightness value.

Through the above steps S1701~S1708, the first grayscale brightness reduction procedure PR1 can radially reduce the grayscale brightness values of all pixels outside the human eye gaze range RG in the image frame FM with the human eye gaze range RG as the center (the grayscale brightness values of pixels within the human eye gaze range RG are not reduced).

Please refer to FIG. 7, which shows a detailed flow chart of step S180 according to an embodiment. In step S1801, as shown in FIG. 2, a human eye picture FM71 is captured by the image capture unit 191.

Next, in step S1802, as shown in FIG2, the human eye detection unit 192 obtains a human eye center position P71 based on the human eye image FM71. The human eye center position P71 is the midpoint of the line connecting the two eyes.

Then, in step S1803, as shown in FIG. 2, the eye detection unit 192 converts the eye center position P71 of the eye picture FM71 into the eye gaze position PL of the image picture FM. The eye detection unit 192 converts the eye center position P71 into the eye gaze position PL according to a two-dimensional coordinate conversion function, for example.

For example, the human eye detection unit 192 converts the human eye center position P71 into the human eye gaze position PL using the above formula (4).

Next, in step S1804, as shown in FIG. 2, the ambient brightness detection unit 193 detects the ambient brightness AL.

Then, in step S1805, as shown in FIG. 2, the second grayscale brightness reduction unit 180 obtains the adjustment reference constant ref according to the ambient brightness AL. The adjustment reference constant ref is proportional to the ambient brightness AL. For example, the second grayscale brightness reduction unit 180 obtains the adjustment reference constant ref by the following formula (11).

Wherein, HDR ( Ref ) _{BL & AL} is the adjustment reference constant ref under the high dynamic range display standard HDR, AL ( Lux ) is the ambient brightness AL. Default L _Max ( nits ) is the maximum brightness, which is, for example, 1200nits under the high dynamic range display standard HDR. Sceen resolution ( milli ) is the screen resolution, for example, 1920× ^10-3 ×1080× ^10-3 , and Pi is a constant, for example, 3.1416.

Then, in step S1806, the second grayscale brightness reduction unit 180 obtains an adjustment level value BRF according to the distance between each pixel and the human eye gaze position PL. Each adjustment level value BRF is proportional to the distance between each pixel and the human eye gaze position PL. For example, the second grayscale brightness reduction unit 180 obtains the adjustment level value BRF by the following formula (6).

為各個像素與人眼注視位置PL的距離。 Among them, BRF ( Brightness Factor ) _{( x,y )} is the adjustment value BRF, HDR ( Ref ) _{BL & AL} is the adjustment value BRF,

is the distance between each pixel and the human eye's gaze position PL.

Next, in step S1807, the second grayscale brightness reduction unit 180 obtains an average grayscale brightness value avg of the image frame FM.

For example, the second grayscale brightness reduction unit 180 obtains the average grayscale brightness value avg using the following formula (12).

Where Grey _Average is the average grayscale brightness value avg, and Grey _{( x,y )} is the grayscale brightness value of each pixel.

Then, in step S1808, the second grayscale brightness reduction unit 180 determines whether the grayscale brightness value of the pixel is 0 or 255. If the grayscale brightness value of the pixel is 0 or 255, then the process proceeds to step S1809.

In step S1809, the second grayscale brightness reduction unit 180 does not reduce the grayscale brightness value of this pixel.

Then, in step S1810, the second grayscale brightness reduction unit 180 determines whether the grayscale brightness value of the pixel is greater than the average grayscale brightness value avg. If the grayscale brightness value of the pixel is greater than the average grayscale brightness value avg, then the process proceeds to step S1811; if the grayscale brightness value of the pixel is less than or equal to the average grayscale brightness value avg, then the process proceeds to step S1812.

In step S1811, the second grayscale brightness reduction unit 180 does not reduce the grayscale brightness value of this pixel.

In step S1812, the second grayscale brightness reduction unit 180 reduces the grayscale brightness value of the pixel according to each adjustment level value.

For example, in step S1811 and step S1812, the first grayscale brightness reduction unit 170 reduces (or does not adjust) the grayscale brightness value according to the following formula (13).

Among them, ( R _out , G _out , B _out ) is the grayscale brightness value of the red/green/blue primary colors after downgrading, R _in is the red grayscale brightness value before adjustment, G _in is the green grayscale brightness value before adjustment, B _in is the blue grayscale brightness value before adjustment, and BRF _{( x, y )} is the adjustment degree value BRF.

Through the above steps S1801~S1812, the second grayscale brightness reduction procedure PR2 only reduces the grayscale brightness value of some pixels. The reduction method is, for example, radial reduction with the human eye gaze position PL as the center. For example, the second grayscale brightness reduction procedure PR2 will only reduce the grayscale brightness value of pixels whose grayscale brightness value is less than or equal to the average grayscale brightness value, and the grayscale brightness value of some pixels within the human eye gaze range RG will also be reduced to maintain the display effect of the high dynamic range display standard.

According to the above embodiment, the smart display 100 converts the linear backlight brightness curve CV1 into the exponential backlight brightness curve CV2 to adjust the degree of brightness variation, thereby avoiding damage to human eyes in a dim environment. In addition, the smart display 100 can use the first grayscale brightness reduction unit 170 and the second grayscale brightness reduction unit 180 to adjust the grayscale brightness of pixels in different ways for the standard dynamic range display standard SDR and the high dynamic range display standard HDR. In this way, the display effect of the standard dynamic range display standard SDR or the high dynamic range display standard HDR can be maintained, and the power saving effect can also be achieved appropriately.

In summary, although the present disclosure has been disclosed as above by the embodiments, it is not intended to limit the present disclosure. Those with ordinary knowledge in the technical field to which the present disclosure belongs can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the scope defined by the attached patent application.

S110,S120,S130,S140,S150,S170,S180: Steps

HDR: High Dynamic Range Display Standard

SDR: Standard Dynamic Range Display Standard

Claims (13)

A brightness adjustment method for a smart display includes: obtaining a backlight brightness curve of the smart display; if the backlight brightness curve is a linear curve, converting the backlight brightness curve into an exponential curve; reading an image screen of the smart display; determining whether the image screen adopts a standard dynamic range (SDR) display standard or a high dynamic range (HDR) display standard; if the image screen adopts the standard dynamic range display standard, executing a first grayscale brightness reduction procedure; and if the image screen adopts the high dynamic range display standard, executing a second grayscale brightness reduction procedure, the second grayscale brightness reduction procedure being different from the first grayscale brightness reduction procedure. The brightness adjustment method of the smart display as described in claim 1, wherein the first grayscale brightness reduction process is centered on a human eye gaze range, and radially reduces the grayscale brightness values of all the multiple pixels outside the human eye gaze range in the image screen. The brightness adjustment method of the smart display as described in claim 2, wherein the first grayscale brightness reduction procedure includes: photographing a human eye picture; According to the human eye picture, obtaining the center position of the human eye; converting the center position of the human eye to the human eye gaze position; according to the human eye gaze position, obtaining the human eye gaze range; detecting an ambient brightness; according to the ambient brightness, obtaining an adjustment reference constant; according to the adjustment reference constant and the distance between each pixel and the human eye gaze position, obtaining an adjustment degree value; and reducing the grayscale brightness values of all the pixels outside the human eye gaze range in the image picture by using the adjustment degree values. The brightness adjustment method of a smart display as described in claim 3, wherein the human eye gaze position is located at the center of the human eye gaze range. A brightness adjustment method for a smart display as described in claim 3, wherein the adjustment reference constant is proportional to the ambient brightness. The brightness adjustment method of a smart display as described in claim 3, wherein each adjustment degree value is proportional to the distance between each pixel and the position where the human eye is looking. The brightness adjustment method of the smart display as described in claim 1, wherein the second grayscale brightness reduction process is to radially reduce the grayscale brightness values of a portion of the plurality of pixels in the image screen with the eye gaze position as the center. The brightness adjustment method of the smart display as described in claim 7, wherein the second grayscale brightness reduction procedure includes: photographing a human eye image; obtaining a human eye center position based on the human eye image; converting the human eye center position to the human eye gaze position; detecting an ambient brightness; obtaining an adjustment reference constant based on the ambient brightness; obtaining an adjustment degree value based on the adjustment reference constant and the distance between each pixel and the human eye gaze position; obtaining An average grayscale brightness value of the image is obtained; if the grayscale brightness value of one of the pixels is 0 or 255, the grayscale brightness value is not reduced; if the grayscale brightness value of one of the pixels is greater than the average grayscale brightness value, the grayscale brightness value is not reduced; and if the grayscale brightness value of one of the pixels is less than or equal to the average grayscale brightness value, the grayscale brightness value is reduced according to each adjustment degree value. A brightness adjustment method for a smart display as described in claim 8, wherein the adjustment reference constant is proportional to the ambient brightness. The brightness adjustment method of a smart display as described in claim 8, wherein each adjustment degree value is proportional to the distance between each pixel and the position where the human eye is looking. A smart display includes: a backlight control unit, which controls the backlight of the smart display according to a backlight brightness curve; a conversion unit, if the backlight brightness curve is a linear curve, the conversion unit converts the backlight brightness curve into an exponential curve; a display standard judgment unit, which is used to read an image frame of the smart display and judge whether the image frame adopts a standard dynamic range (SDR) display standard or a high dynamic range (HDR) display standard. A first grayscale brightness reduction unit is provided. If the image screen adopts the standard dynamic range display standard, the first grayscale brightness reduction unit executes a first grayscale brightness reduction procedure; and a second grayscale brightness reduction unit is provided. If the image screen adopts the high dynamic range display standard, the second grayscale brightness reduction unit executes a second grayscale brightness reduction procedure, and the second grayscale brightness reduction procedure is different from the first grayscale brightness reduction procedure. The smart display as described in claim 11, wherein the first grayscale brightness reduction process is centered on a person's eye gaze range, and radially reduces the grayscale brightness values of all the multiple pixels outside the person's eye gaze range in the image screen. The smart display as described in claim 11, wherein the second grayscale brightness reduction process is to radially reduce the grayscale brightness values of a portion of the plurality of pixels in the image screen with the eye gaze position as the center.

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