A method and system for adaptive brightness control of outdoor LED screen

Abstract

The present application relates to an outdoor LED screen adaptive brightness control method and system, the method comprising: obtaining front-screen brightness data in front of the LED screen and rear-screen brightness data behind the LED screen; calculating the brightness difference value between the front-screen brightness data and the rear-screen brightness data; obtaining front-screen color data in front of the LED screen, and obtaining peripheral color data next to the LED screen; calculating the color difference value between the front-screen color data and the peripheral color data; obtaining a brightness adjustment value according to the brightness difference value and the color difference value; calculating the difference between the change of the front-screen color data and the change of the peripheral color data as a fluctuation difference value; obtaining a color adjustment value according to the color difference value and the fluctuation difference value; adjusting the brightness of the LED screen according to the brightness adjustment value; adjusting the color of the LED screen according to the color adjustment value, the larger the color adjustment value; the LED screen can adapt to the light changes at different times of the day and change the brightness or color.

Description

Technical Field

[0001] The present application relates to the field of LED brightness control, and in particular to an outdoor LED screen adaptive brightness control method and system thereof. Background Art

[0002] With the continuous development of display technology, the display screen has evolved from incandescent lamp or fluorescent lamp to LED screen. The LED screen has a low voltage power supply, with a supply voltage between 6-24V, which is particularly suitable for public places. It also has low energy consumption. The energy consumption of LED screen is lower than that of the same light effect. Incandescent lamp The display screen is reduced by 80%. LED also has a display stability of 100,000 hours. Light decay In addition, the response time of incandescent lamps is in milliseconds, while that of LED lamps is in nanoseconds. The fast response time is conducive to the rapid change of displayed images.

[0003] LED screens can perform well in different environments. The brightness of outdoor LED screens is usually closely related to the installation location, orientation, environment, etc. If the outdoor LED screen is installed facing south or slightly south, when the direct sunlight is strong, the brightness of the screen needs to be relatively high, generally above 7000cd / m2; if it is placed in the north or slightly north, the brightness can be appropriately lower, around 5500cd / m2; if the outdoor LED screen is blocked by high-rise buildings or trees in the city, the brightness can be 4000cd / m2.

[0004] After the LED screen is set up according to regional differences, it can roughly adapt to the characteristics of the environment. However, the light at a fixed position varies greatly throughout the day, and the existing LED screen cannot change brightness or color to adapt to the light changes at different times of the day. Summary of the invention

[0005] In order to allow the LED screen to adapt to the changes in light at different times of the day and change brightness or color, the present application provides an outdoor LED screen adaptive brightness control method and system.

[0006] In the first aspect, the present application provides an outdoor LED screen adaptive brightness control method, which adopts the following technical solution:

[0007] An outdoor LED screen adaptive brightness control method comprises the following steps:

[0008] Obtain the brightness data in front of the LED screen and the brightness data behind the LED screen;

[0009] Calculate the difference between the brightness data in front of the screen and the brightness data behind the screen as a brightness difference value;

[0010] Get the color data in front of the LED screen and the surrounding color data beside the LED screen;

[0011] Calculate the difference between the screen color data and the peripheral color data as a color difference value;

[0012] Obtaining a brightness adjustment value by weighted calculation according to the brightness difference value and the color difference value;

[0013] Adjusting the brightness of the LED screen according to the brightness adjustment value, the larger the brightness adjustment value, the lower the brightness of the LED screen, and the smaller the brightness adjustment value, the higher the brightness of the LED screen;

[0014] Calculate the difference between the color data change in front of the screen and the color data change in the surrounding area as a fluctuation difference value;

[0015] Calculate a color adjustment value according to the color difference value and the fluctuation difference value;

[0016] The color of the LED screen is adjusted according to the color adjustment value. The larger the color adjustment value is, the smaller the color difference of the LED screen image is. The smaller the color adjustment value is, the larger the color difference of the LED screen image is.

[0017] By adopting the above technical scheme, the brightness value is adjusted according to the brightness difference between the front and back of the LED screen. During the day, the brightness difference between the front and back of the LED screen is small, and the LED screen needs to have high brightness. At night, the brightness difference between the front and back of the LED screen is large, and the LED screen needs to have low brightness. The color difference is adjusted according to the color difference between the front and back of the LED screen. During the day, the color difference between the front and back of the LED screen is small and the fluctuation is small, and the color difference of the image on the LED screen needs to be large to highlight the image content. At night, the brightness difference between the front and back of the LED screen is large and the fluctuation is large, and the color difference of the image on the LED screen needs to be small to avoid excessive distortion of the image, so that the LED screen can adapt to the light changes at different times of the day and change the brightness or color.

[0018] Preferably, the step of obtaining the screen brightness data in front of the LED screen further includes:

[0019] Scanning a projection area preset in front of the LED screen to obtain first light intensity data of the projection area;

[0020] Calculate a first average value of the first light intensity data in the projection area and position data of a light intensity focus point in the projection area, wherein the light intensity focus point is a center point of an area with a higher light intensity value in the projection area;

[0021] Calculating a first moving distance value of the light intensity focusing point within a preset time period;

[0022] If the first moving distance value is less than or equal to a preset first reference distance value, the first average value is output as the brightness data in front of the screen; otherwise, if the first moving distance value is greater than the first reference distance value, the first average value is amplified according to the first moving distance value, and the amplified first average value is output as the brightness data in front of the screen.

[0023] By adopting the above technical solution, the position data of the light intensity focusing point is calculated. If the light intensity focusing point is moving slowly, it means that the sun is in front of the LED screen. At this time, the brightness data in front of the screen is output according to the moving distance of the sun. If the light intensity focusing point is moving quickly, it means that there are vehicle headlights in front of the LED screen. In this case, the brightness data in front of the screen is output according to the moving distance of the vehicle. The output brightness data in front of the screen affects the change of the brightness of the LED screen, thereby facilitating the automatic adjustment of the brightness of the LED screen.

[0024] Preferably, the step of obtaining the brightness data behind the LED screen further includes:

[0025] Scanning the reflection area behind the LED screen to obtain second light intensity data of the reflection area;

[0026] Calculating a second average value of the second light intensity data in the reflection area and graphic data of a shadow shape in the reflection area, wherein the shadow area is a shape of an area with a lower light intensity value in the reflection area;

[0027] Calculating an area change value and a second moving distance value of the shadow shape within a preset time period;

[0028] If the area change value is less than or equal to the preset reference change value and the second moving distance value is less than or equal to the preset second reference distance value, the second average value is output as the brightness data behind the screen; otherwise, if the area change value is greater than the preset reference change value or the moving distance is greater than the second reference distance value, the second average value is reduced according to the area change value and the moving distance, and the reduced second average value is output as the brightness data behind the screen.

[0029] By adopting the above technical solution, the area change value of the shadow shape is calculated. If the area change value is changing slowly or even not changing, it means that the sun is moving slowly in front of the LED screen. At this time, the brightness data behind the screen is output according to the moving distance of the sun. If the area change value is changing rapidly, it means that there are vehicle headlights in front of the LED screen. In this case, the brightness data behind the screen is output according to the moving distance of the vehicle. The output brightness data behind the screen affects the change of the brightness of the LED screen, which is conducive to the automatic adjustment of the brightness of the LED screen.

[0030] Preferably, the step of obtaining the color data in front of the LED screen further includes:

[0031] Photographing a display area in front of the LED screen to obtain first image data of the display area;

[0032] Calculate a first R average value, a first G average value, and a first B average value corresponding to the three colors RGB in the first image data;

[0033] Calculate the change values ​​of the first R average value, the first G average value, and the first B average value within a preset time period as an R change value, a G change value, and a B change value;

[0034] Calculating an average of the first R average value, the first G average value, and the first B average value as a first output average value;

[0035] Calculating discrete values ​​of the R change value, the G change value, and the B change value as color discrete values;

[0036] Calculate a weighted average value by using the R change value, the G change value and the B change value as weights;

[0037] If the color discrete value is less than or equal to a preset reference discrete value, the first output average value is output as the screen color data; otherwise, if the color discrete value is greater than the reference discrete value, the weighted average value is output as the screen color data.

[0038] By adopting the above technical solution, the change value of the image color in the display area in front of the screen is obtained, and the data is selected as the color data in front of the screen according to the change degree and discreteness of the change value. The distribution and change of the color in the projection area can affect the change of the color of the LED screen, thereby facilitating the automatic adjustment of the color of the LED screen.

[0039] Preferably, the step of obtaining the surrounding color data around the LED screen further includes:

[0040] Photographing a side area next to the LED screen to obtain second image data of the side area;

[0041] Calculate a second R average value, a second G average value, and a second B average value corresponding to the three colors RGB in the second image data;

[0042] Calculating a weighted average of the second R average value, the second G average value, and the second B average value as a second output average value;

[0043] The second output average value is output as peripheral color data.

[0044] By adopting the above technical solution, the change value of the image color in the side area is obtained, and the calculated color average is used as the surrounding color data. The distribution and change of colors in the environment can affect the change of the color of the LED screen, which is conducive to the automatic adjustment of the color of the LED screen.

[0045] Preferably, the step of calculating the weighted average of the second R average value, the second G average value and the second B average value as the second output average value further includes:

[0046] The second image data includes a first area, a second area and a third area arranged in sequence;

[0047] Calculate a first R pixel value sum of the R color in the first area, calculate a second R pixel value sum of the R color in the second area, and calculate a third R pixel value sum of the R color in the third area;

[0048] Calculate the corresponding first weighting factor, second weighting factor and third weighting factor according to the first R pixel value sum, the second R pixel value sum and the third R pixel value sum;

[0049] The first weighting factor, the second weighting factor and the second weighting factor are combined with the second R average value, the second G average value and the second B average value to calculate a second output average value.

[0050] By adopting the above technical solution, by calculating the colors of different areas in the image and obtaining the value representing the single color distribution in the second image data through a weighted algorithm, the second output average value can reflect the color changes in the environment, thereby facilitating the automatic adjustment of the color of the LED screen.

[0051] Preferably, the method further comprises the steps of:

[0052] Get the temperature and humidity values ​​around the LED screen;

[0053] Calculating a light resistance value according to the temperature value and the humidity value;

[0054] The brightness value of the LED screen is adjusted according to the light resistance value; the larger the light resistance value is, the larger the brightness value is, and the smaller the light resistance value is, the smaller the brightness value is.

[0055] By adopting the above technical solution, when the temperature and humidity change, the fog environment in the air will change, so the imaging resistance of light will also change. The thicker the fog, the closer the imaging distance, so the brightness needs to be increased; the lighter the fog, the farther the imaging distance, so the brightness needs to be reduced.

[0056] Preferably, the method further comprises the steps of:

[0057] Get the surface pressure value of the LED screen;

[0058] Calculate the position data of the distribution center point of the pressure on the LED screen surface;

[0059] Calculate the absolute value of the height difference between the distribution center point and the center point of the LED screen;

[0060] The brightness value of the LED screen is adjusted according to the absolute value of the height difference; the larger the absolute value of the height difference is, the larger the brightness value is, and the smaller the absolute value of the height difference is, the smaller the brightness value is.

[0061] By adopting the above technical solution, as the fog changes, the amount of condensed water generated on the surface of the LED screen will also change. As time goes by, the condensed water increases in height from top to bottom and disappears from top to bottom. The more condensed water there is, the greater the pressure is. Therefore, adjusting the brightness value of the LED screen according to the position data of the center point of the pressure distribution can allow the LED screen to adjust with the change of pressure, which is conducive to automatic adjustment.

[0062] In the second aspect, the present application provides an outdoor LED screen adaptive brightness control system, which adopts the following technical solutions:

[0063] An outdoor LED screen adaptive brightness control system runs a computer program corresponding to the outdoor LED screen adaptive brightness control method described above.

[0064] This application has at least the following beneficial effects:

[0065] (1) The brightness difference value is calculated by the brightness data in front of the LED screen and the brightness data behind the screen. The brightness of the LED screen is adjusted according to the brightness difference value. The brightness difference value is small during the day and large at night. Therefore, it is beneficial for the brightness of the LED screen to adapt to the changes in ambient brightness and automatically adjust;

[0066] (2) The color adjustment value is calculated by the color data in front of the LED screen and the surrounding color data. The color of the LED screen is adjusted according to the color adjustment value. The color adjustment value is small during the day and large at night. This helps the color of the LED screen to adapt to the changes in ambient brightness and automatically adjust.

[0067] (3) By detecting the temperature, humidity and condensation of the environment in which the LED screen is located to adjust the brightness of the LED screen, the brightness of the LED screen can be further adjusted to adapt to environmental changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is a schematic diagram of the method flow of the adaptive brightness control method for outdoor LED screens of the present application;

[0069] Figure 2It is the principle diagram of the adaptive brightness control system of the outdoor LED screen of this application;

[0070] Figure 3 It is a flowchart of a method for obtaining brightness data in front of a screen;

[0071] Figure 4 It is a flowchart of a method for obtaining brightness data behind a screen;

[0072] Figure 5 It is a flowchart of a method for obtaining color data in front of a screen;

[0073] Figure 6 is a flowchart of a method for obtaining surrounding color data;

[0074] Figure 7 is a flow chart of a method for calculating a second output average value;

[0075] Figure 8 It is a flow chart of a method for adjusting the brightness of an LED screen according to temperature and humidity;

[0076] Fig. 9 It is a flow chart of a method for adjusting the brightness of an LED screen according to surface pressure. DETAILED DESCRIPTION

[0077] The following is combined with Figure 1-9 This application is described in further detail.

[0078] The embodiments of the present application are further described in detail below in conjunction with the drawings in the specification.

[0079] The present application embodiment discloses a method for adaptive brightness control of an outdoor LED screen, such as Figure 1 and Figure 2 As shown, the following steps are included:

[0080] Obtain the brightness data in front of the LED screen and the brightness data behind the LED screen. The LED screen uses an adjustable RGB primary color dimming screen, which is in the shape of a cuboid and can be erected beside the road through a support pole, or placed above the road through a crossbar or beam, such as a road checkpoint or a highway toll station. The side of the LED screen that displays the content is facing the oncoming vehicle, and can display text or images. A variety of detection equipment or sensors can be installed on the LED screen, for example, photoresistors and their operational amplifier circuits, brightness sensors, CCD cameras, color cameras, temperature sensors, humidity sensors, integrated temperature and humidity sensors, pressure sensors, piezoelectric sensors and other devices or sensors can be installed on the front and back of the LED screen.

[0081] The photoresistor and its operational amplifier circuit can measure the brightness between the front and back of the LED screen. When the photoresistor encounters sufficient light intensity, as the light intensity becomes stronger, the resistance of the photoresistor will decrease, so that the corresponding operational amplifier circuit can output the corresponding light intensity signal. For example, the front of the LED screen has sufficient solar radiation, the resistance of the photoresistor is low, and the corresponding operational amplifier circuit outputs a high-voltage light intensity signal; the back of the LED screen has insufficient solar radiation, the resistance of the photoresistor is high, and the corresponding operational amplifier circuit outputs a low-voltage light intensity signal. The brightness sensor can use the GY-485-44009 photosensitive sensor. The GY-485-44009 photosensitive sensor is a low-cost 485 communication light intensity sensor module with an operating voltage of 3-5v, low power consumption, small size, and easy installation. Its working principle is that the built-in single-chip microcomputer reads the light intensity sensor, calculates the actual light intensity, and transmits data through the 485 chip. The 485 communication can be used for long-distance transmission and multi-point data transmission. The light intensity can also be calculated from the captured image.

[0082] The CCD camera can collect and output black and white images. If a linear CCD camera is used, a single-line black and white image can be output. The linear CCD camera with a pan-tilt scanner can output a full-frame black and white image. The color camera can collect and output color images. The temperature sensor can use a single-bus DS18B20 digital thermometer, the humidity sensor can use a lithium chloride humidity sensor and its peripheral circuits, and the temperature and humidity sensor can use an HDC1080 sensor or a DHT11 sensor to output digital signals of temperature and humidity.

[0083] The LED screen can additionally be equipped with a single-chip microcomputer or PLC as a data processing center. A single-chip microcomputer is preferably used. The single-chip microcomputer can collect analog signals, receive digital signals, and calculate and output digital signals or control signals adapted to the LED screen. The LED screen changes brightness and color in response to the control signal. The color includes the proportion of all or part of the RBG light.

[0084] like Figure 2 and Figure 3 As shown, based on the pan-tilt system, a preset projection area in front of the LED screen is scanned. The projection area is the projection space of the LED screen content. For example, the projection area can be a highway or a display square. This embodiment takes the highway as an example. The single-chip microcomputer can obtain the first light intensity data of the projection area through the photosensitive sensor, and the single-chip microcomputer can also obtain the first light intensity data of the projection area through the camera. The first average value of the first light intensity data in the projection area and the position data of the light intensity focusing point in the projection area are calculated. The light intensity focusing point is the center point of the area with higher light intensity value in the projection area. For example, during the day, the sun is in front of the LED screen, and the light intensity focusing point of the projection area is the area where the sun is located; at night, the light intensity focusing point is the center of the bright spot of the projection imaging of the light on the LED screen on the road.

[0085] The first moving distance value of the light intensity focus point within the preset time period is calculated. For example, at 7 o'clock in the morning, the height of the light intensity focus point is calculated to be 8, at 9 o'clock in the morning, the height of the light intensity focus point is calculated to be 12, the preset time period is two hours, and the first moving distance value is 4. If the first moving distance value is less than or equal to the preset first reference distance value, the first average value is output as the brightness data in front of the screen; the preset first reference distance can be 6, and if there is no influence of other factors, the calculated first average value is directly used as the brightness data in front of the screen. For example, at 7 o'clock in the morning, the height of the light intensity focus point is calculated to be 8, and at 8 o'clock in the morning, a vehicle passes by with a strong high beam, then the height of the light intensity focus point is calculated to be 1, the preset time period is two hours, and the first moving distance value is 6. If the first moving distance value is greater than the first reference distance value, the first average value is amplified according to the first moving distance value, and the amplified first average value is output as the brightness data in front of the screen, and the farther the distance of the vehicle with a strong high beam, the greater the first moving distance value, and therefore the greater the brightness data in front of the screen.

[0086] like Figure 2 and Figure 4 As shown, the step of obtaining the brightness data behind the LED screen includes: scanning the reflection area behind the LED screen, obtaining the second light intensity data of the reflection area, and the method of scanning and obtaining the second light intensity data can be similar or the same as the method of scanning and obtaining the first light intensity data. Calculate the second average value of the second light intensity data in the reflection area and the graphic data of the shadow shape in the reflection area. The shadow area is the shape of the area with lower light intensity value in the reflection area. For example, the shadow area is the projection of the LED screen on the ground under the sun. With the different light intensity focus points, the position and shape of the shadow area will also change. When the sun is at its highest, the position of the shadow area is closest to the LED screen, and the projection area is the smallest; when a vehicle with strong high beam passes the LED screen at night, the position of the shadow area is close to the LED screen, and the projection area changes from large to small.

[0087] Calculate the area change value and the second moving distance value of the shadow shape within the preset time period. For example, from 7 am to 9 am, the calculated area change value is 5, the preset time period is two hours, and the first moving distance value is 5. The preset reference change value may be 4, and the preset second reference distance value is 4. If the area change value is less than or equal to the reference change value and the second moving distance value is less than or equal to the second reference distance value, then the second average value is output as the brightness data behind the screen. For example, at 9 pm, the calculated area change value of the vehicle passing by is 10, the preset time period is two hours, and the first moving distance value is 10. If the area change value is greater than the reference change value or the moving distance is greater than the second reference distance value, the second average value is reduced according to the area change value and the moving distance, and the reduced second average value is output as the brightness data behind the screen.

[0088] The difference between the brightness data in front of the screen and the brightness data behind the screen is calculated as the brightness difference value. During the day, the brightness data in front of the screen is greater than the brightness data behind the screen, the first average value will not be enlarged, the second average value will not be reduced, and the difference between the front and back is not large. The brightness will become stronger as the sunlight becomes stronger. When a vehicle passes by with its lights on, if the car lights are stronger than the recognized sunlight, the first average value will be enlarged, and the LED screen will adjust the brightness according to the situation of the vehicle, such as increasing the brightness. At night, the brightness data in front of the screen is greater than the brightness data behind the screen, and the difference between the front and back is large. When a vehicle passes by with its lights on, the first average value will be enlarged, and the second average value will be reduced, so that the brightness is gradually increased when the vehicle approaches, and after the vehicle passes, the brightness is reduced and restored to the brightness when there is no car.

[0089] Get the color data in front of the LED screen, and get the surrounding color data next to the LED screen.

[0090] like Figure 2 and Figure 5 As shown, based on the color camera shooting the display area in front of the LED screen, the display area can also be a projection area, and the first image data of the display area is obtained. The first R average value, the first G average value and the first B average value corresponding to the three colors RGB in the first image data are calculated. The change values ​​of the first R average value, the first G average value and the first B average value within a preset time period are calculated as R change value, G change value and B change value, and the preset time period can be two hours. The average value of the first R average value, the first G average value and the first B average value is calculated as the first output average value. The discrete values ​​of the R change value, the G change value and the B change value are calculated as color discrete values. The discrete values ​​can be discrete degrees, and the standard deviation can be used for calculation. The weighted average value is calculated using the R change value, the G change value and the B change value as weights.

[0091] Among them, the preset reference discrete value can be 100, the imaging color distribution during the day is relatively stable, and its discreteness can be 50, and the imaging color distribution at night is unstable, and the LED screen has a greater impact on the ambient color, and its discreteness can be 200. During the day, if the color discrete value is less than or equal to the reference discrete value, the first output average value is output as the color data in front of the screen; at night, if the color discrete value is greater than the reference discrete value, the weighted average value is output as the color data in front of the screen, which can allow the change value of the pixel color to affect the imaging color of the LED screen.

[0092] like Figure 2 and Figure 6As shown, the step of obtaining the peripheral color data beside the LED screen includes: photographing the side area beside the LED screen to obtain the second image data of the side area; the method of obtaining the second image data may be similar to or the same as the method of obtaining the first image data. Calculate the second R average value, the second G average value, and the second B average value corresponding to the three colors RGB in the second image data. Calculate the weighted average value of the second R average value, the second G average value, and the second B average value as the second output average value.

[0093] like Figure 2 and Figure 7 As shown, the second image data includes a first area, a second area and a third area arranged in sequence, the first area can be at the bottom in space, the second area can be in the middle, and the third area can be at the top. In specific implementation, the first area, the second area and the third area can be represented in the image as follows: during the day, the first area is the ground area, the second area is the distant area of ​​the road, and the third area is the sky area. The first R pixel value sum of the R color in the first area is calculated, the second R pixel value sum of the R color in the second area is calculated, and the third R pixel value sum of the R color in the third area is calculated; the corresponding first weighting factor, the second weighting factor and the second weighting factor are calculated according to the first R pixel value sum, the second R pixel value sum and the third R pixel value sum; the first weighting factor, the second weighting factor and the second weighting factor are combined with the second R average value, the second G average value and the second B average value to calculate the second output average value.

[0094] like Figure 1 and Figure 2 As shown, the second output average value is output as the surrounding color data. The LED screen has little impact on the environment behind it, while the car lights have a greater impact on the environment behind the LED screen. Therefore, there is no need to select processing, and the second output average value is directly output as the surrounding color data.

[0095] The difference between the color data in front of the screen and the surrounding color data is calculated as the color difference value, and the brightness adjustment value is obtained by weighted calculation based on the brightness difference value and the color difference value. The brightness of the LED screen is adjusted according to the brightness adjustment value. The larger the brightness adjustment value, the lower the brightness of the LED screen, and the smaller the brightness adjustment value, the higher the brightness of the LED screen. The larger the difference between the front and back of the LED screen, the more it is necessary to reduce the brightness of the LED screen so that the LED screen is convenient for people to watch the content; the smaller the brightness adjustment value, the smaller the difference between the front and back of the LED screen, so the brightness of the LED screen needs to be increased so that the LED screen can attract people's attention.

[0096] The difference between the color data change in front of the screen and the color data change in the surrounding area is calculated as the fluctuation difference value. The toggle difference value can be the difference between the amount of color data change in front of the screen and the amount of color data change in the surrounding area within two hours. Then, a color adjustment value is obtained by weighted calculation based on the color difference value and the fluctuation difference value. The color of the LED screen is adjusted according to the color adjustment value. The larger the color adjustment value, the smaller the color difference of the LED screen image. The smaller the color adjustment value, the greater the color difference of the LED screen image. The color difference can be the contrast or the degree of image sharpening. The color difference can also be the change amplitude of the LED screen image content. If the amount of color data change in front of the screen is larger, the amount of change in the surrounding color data is smaller, the fluctuation difference value is larger, and the color difference value will be larger accordingly. The value after weighted calculation of the color difference value and the fluctuation difference value is larger, so the color difference is smaller. When the environmental color changes greatly, the change of the image color is kept small, the image stability is improved, and it is convenient for people to watch the content.

[0097] During the day, the brightness value is adjusted according to the brightness difference between the front and back of the LED screen, that is, between the front and back. The brightness difference between the front and back of the LED screen is small, so the brightness of the LED screen needs to be high. The position data of the light intensity focus point is calculated. If the light intensity focus point is moving slowly, it means that the sun is in front of the LED screen. At this time, the brightness data in front of the screen is output according to the moving distance of the sun. If the light intensity focus point is moving quickly, it means that there are vehicle headlights in front of the LED screen. The brightness data in front of the screen is output according to the moving distance of the vehicle. The output brightness data in front of the screen can affect the change of the brightness of the LED screen.

[0098] In addition, the color difference can be adjusted according to the color difference between the front and back of the LED screen. The color difference between the front and back of the LED screen is small and the fluctuation is small. The color difference of the image on the LED screen needs to be large to highlight the image content. The change value of the image color in the display area in front of the screen is obtained, and the data is selected as the color data in front of the screen through the degree of change of the change value and the degree of discreteness. The distribution and change of color in the projection area can affect the change of the color of the LED screen, which is conducive to the automatic adjustment of the color of the LED screen during the daytime.

[0099] At night, the brightness difference between the front and back of the LED screen is large, so the LED screen needs to be at a low brightness. Calculate the area change value of the shadow shape. If the area change value is changing slowly or even not changing, it means that the sun is moving slowly in front of the LED screen. At this time, the brightness data behind the screen is output according to the moving distance of the sun. If the area change value is changing rapidly, it means that there are vehicle headlights in front of the LED screen. In this case, the brightness data behind the screen is output according to the moving distance of the vehicle. The output brightness data behind the screen affects the change of the brightness of the LED screen.

[0100] Among them, the brightness difference between the front and back of the LED screen is large and fluctuates greatly. The color difference of the image on the LED screen needs to be small to avoid excessive distortion of the image. The change value of the image color in the side area is obtained. By calculating the color of different areas in the image, the value representing the single color distribution in the second image data is calculated by a weighted algorithm, so that the second output average value can reflect the color change in the environment. By using the calculated color average value as the surrounding color data, the distribution and change of the color in the environment can also affect the color change of the LED screen, which is conducive to the automatic adjustment of the color of the LED screen during the night time period.

[0101] In addition to adjusting the brightness and color of the LED screen by the brightness and color of the surrounding environment, the brightness and color of the LED screen can also be adjusted by obtaining other environmental parameters around the LED screen.

[0102] like Figure 2 and Figure 8 As shown, the light resistance value can be calculated based on the temperature and humidity values ​​obtained from the surrounding environment of the LED screen. The light resistance value can be obtained by weighted calculation using the temperature and humidity values, or by looking up a table. The brightness value of the LED screen is adjusted according to the light resistance value; the larger the light resistance value, the larger the brightness value, and the smaller the light resistance value, the smaller the brightness value. Figure 2 and Fig. 9 As shown, the surface pressure value of the LED screen can also be obtained from the surface of the LED screen, the position data of the distribution center point of the surface pressure of the LED screen can be calculated, the absolute value of the height difference between the distribution center point and the center point of the LED screen can be calculated, and the brightness value of the LED screen can be adjusted according to the absolute value of the height difference; the greater the absolute value of the height difference, the greater the brightness value, and the smaller the absolute value of the height difference, the smaller the brightness value.

[0103] When the temperature and humidity change, the fog environment in the air will change, so the imaging resistance of light will also change. The thicker the fog, the closer the imaging distance, so the brightness needs to be increased. The lighter the fog, the farther the imaging distance, so the brightness needs to be reduced. At the same time, the change in fog will also cause the amount of condensed water produced on the surface of the LED screen to change. As time goes by, when the fog becomes thicker, the condensed water on the surface of the LED screen increases in height from top to bottom. When the fog becomes lighter, the condensed water on the surface of the LED screen will also disappear from top to bottom. The more condensed water there is, the greater the pressure is. Therefore, adjusting the brightness value of the LED screen according to the position data of the center point of the pressure distribution can allow the LED screen to adjust with the change of pressure, which is conducive to automatic adjustment.

[0104] The present application also discloses an outdoor LED screen adaptive brightness control system. Figure 2 As shown, it includes: running a computer program corresponding to the outdoor LED screen adaptive brightness control method recorded above.

[0105] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An outdoor LED screen adaptive brightness control method, characterized by: The steps include: Obtain the brightness data in front of the LED screen and the brightness data behind the LED screen; Calculate the difference between the brightness data in front of the screen and the brightness data behind the screen as a brightness difference value; Get the color data in front of the LED screen and the surrounding color data beside the LED screen; Calculate the difference between the screen color data and the peripheral color data as a color difference value; Obtaining a brightness adjustment value by weighted calculation according to the brightness difference value and the color difference value; Adjusting the brightness of the LED screen according to the brightness adjustment value, the larger the brightness adjustment value, the lower the brightness of the LED screen, and the smaller the brightness adjustment value, the higher the brightness of the LED screen; Calculate the difference between the color data change in front of the screen and the color data change in the surrounding area as a fluctuation difference value; Calculate a color adjustment value according to the color difference value and the fluctuation difference value; Adjusting the color of the LED screen according to the color adjustment value, the larger the color adjustment value is, the smaller the color difference of the LED screen image is, and the smaller the color adjustment value is, the larger the color difference of the LED screen image is; The greater the change in the color data in front of the screen, the smaller the change in the surrounding color data, the larger the fluctuation difference value, the correspondingly larger the color difference value, the larger the value after weighted calculation of the color difference value and the fluctuation difference value, the smaller the color difference, and the smaller the change in the color of the LED screen image when the ambient color changes greatly.

2. The method according to claim 1, characterized in that: The step of obtaining the screen brightness data in front of the LED screen also includes: Scanning a projection area preset in front of the LED screen to obtain first light intensity data of the projection area; Calculate a first average value of the first light intensity data in the projection area and position data of a light intensity focus point in the projection area, wherein the light intensity focus point is a center point of an area with a higher light intensity value in the projection area; Calculating a first moving distance value of the light intensity focusing point within a preset time period; If the first moving distance value is less than or equal to a preset first reference distance value, the first average value is output as the brightness data in front of the screen; otherwise, if the first moving distance value is greater than the first reference distance value, the first average value is amplified according to the first moving distance value, and the amplified first average value is output as the brightness data in front of the screen.

3. The method according to claim 1, characterized in that: The step of obtaining the brightness data behind the LED screen also includes: Scanning the reflection area behind the LED screen to obtain second light intensity data of the reflection area; Calculating a second average value of the second light intensity data in the reflection area and graphic data of a shadow shape in the reflection area, wherein the shadow shape is a shape of an area with a lower light intensity value in the reflection area; Calculating an area change value and a second moving distance value of the shadow shape within a preset time period; If the area change value is less than or equal to the preset reference change value and the second moving distance value is less than or equal to the preset second reference distance value, the second average value is output as the brightness data behind the screen; otherwise, if the area change value is greater than the preset reference change value or the moving distance is greater than the second reference distance value, the second average value is reduced according to the area change value and the moving distance, and the reduced second average value is output as the brightness data behind the screen.

4. The method according to claim 1, characterized in that: The step of obtaining the color data in front of the LED screen also includes: Photographing a display area in front of the LED screen to obtain first image data of the display area; Calculate a first R average value, a first G average value, and a first B average value corresponding to the three colors RGB in the first image data; Calculate the change values ​​of the first R average value, the first G average value, and the first B average value within a preset time period as an R change value, a G change value, and a B change value; Calculating an average of the first R average value, the first G average value, and the first B average value as a first output average value; Calculating discrete values ​​of the R change value, the G change value, and the B change value as color discrete values; Calculate a weighted average value by using the R change value, the G change value and the B change value as weights; If the color discrete value is less than or equal to a preset reference discrete value, the first output average value is output as the screen color data; otherwise, if the color discrete value is greater than the reference discrete value, the weighted average value is output as the screen color data.

5. The method according to claim 1, characterized in that: The step of obtaining the surrounding color data around the LED screen also includes: Photographing a side area next to the LED screen to obtain second image data of the side area; Calculate a second R average value, a second G average value, and a second B average value corresponding to the three colors RGB in the second image data; Calculating a weighted average of the second R average value, the second G average value, and the second B average value as a second output average value; The second output average value is output as peripheral color data.

6. The method according to claim 5, characterized in that: The step of calculating the weighted average of the second R average value, the second G average value and the second B average value as the second output average value further includes: The second image data includes a first area, a second area and a third area arranged in sequence; Calculate a first R pixel value sum of the R color in the first area, calculate a second R pixel value sum of the R color in the second area, and calculate a third R pixel value sum of the R color in the third area; Calculate the corresponding first weighting factor, second weighting factor and third weighting factor according to the first R pixel value sum, the second R pixel value sum and the third R pixel value sum; The first weighting factor, the second weighting factor and the second weighting factor are combined with the second R average value, the second G average value and the second B average value to calculate a second output average value.

7. The method according to claim 1, characterized in that: The method further comprises the steps of: Get the temperature and humidity values ​​around the LED screen; Calculating a light resistance value according to the temperature value and the humidity value; The brightness value of the LED screen is adjusted according to the light resistance value; the larger the light resistance value is, the larger the brightness value is, and the smaller the light resistance value is, the smaller the brightness value is.

8. The method according to claim 1, characterized in that: The method further comprises the steps of: Get the surface pressure value of the LED screen; Calculate the position data of the distribution center point of the pressure on the LED screen surface; Calculate the absolute value of the height difference between the distribution center point and the center point of the LED screen; The brightness value of the LED screen is adjusted according to the absolute value of the height difference; the larger the absolute value of the height difference is, the larger the brightness value is, and the smaller the absolute value of the height difference is, the smaller the brightness value is.

9. An outdoor LED screen adaptive brightness control system, characterized by: A computer program corresponding to the outdoor LED screen adaptive brightness control method as described in any one of claims 1-8 is run.

Images