WO2024113162A1

WO2024113162A1 - Luminance compensation method and apparatus, device, and storage medium

Info

Publication number: WO2024113162A1
Application number: PCT/CN2022/135036
Authority: WO
Inventors: 范进华; 聂雪玲
Original assignee: 西安青松光电技术有限公司
Priority date: 2022-11-29
Filing date: 2022-11-29
Publication date: 2024-06-06
Also published as: CN118633119A

Abstract

Disclosed in embodiments of the present application are a luminance compensation method and apparatus, a device and a storage medium. The method comprises: acquiring a plurality of collected images obtained by collecting a display picture of an LED display screen having set grayscale, wherein the compensation times of the plurality of collected images are different; acquiring a first luminance value of each LED lamp bead, in the LED display screen, in each collected image and determining a target luminance value of each LED lamp bead; according to the target luminance value, the first luminance value and the compensation time corresponding to each collected image, determining a compensation coefficient of each LED lamp bead, wherein the compensation coefficient is proportional to a luminance increase value required when the LED lamp bead reaches the target luminance value; when the compensation coefficient of a first LED lamp bead is greater than a coefficient threshold value, determining the compensation coefficient of the first LED lamp bead as the coefficient threshold value; and sending the compensation coefficient to a control chip in the LED display screen, so that the control chip performs luminance compensation on the basis of the compensation coefficient. By adopting the method, the technical problem in the prior art that there are differences in luminance of LED lamp beads of LED display screens can be solved.

Description

Brightness compensation method, device, equipment and storage medium

Technical Field

The embodiments of the present application relate to the technical field of LED display screens, and in particular to a brightness compensation method, device, equipment and storage medium.

Background technique

Light-emitting diode (LED) is a commonly used light-emitting device that can efficiently convert electrical energy into light energy. Therefore, it is widely used in display, lighting and other fields. In the display field, LED display screens can be composed of LED lamp beads, and images are displayed through LED display screens. However, for LED display screens, due to the discreteness of the physical characteristics of each LED lamp bead in brightness, the actual brightness displayed by each LED lamp bead at the same low brightness may vary greatly. This difference is particularly obvious when displaying pure color images, which reduces the display effect of the LED display screen.

Summary of the invention

An embodiment of the present application provides a brightness compensation method, device, equipment and storage medium to solve the technical problem in the related art that there is a difference in brightness displayed by each LED lamp bead of an LED display screen.

In a first aspect, an embodiment of the present application provides a brightness compensation method, including:

Acquire a plurality of collected images, wherein the plurality of collected images include images collected from a display screen of an LED display screen with a set grayscale, and the compensation times of the plurality of collected images are all different;

Obtaining a first brightness value of each LED lamp bead in the LED display screen in each collected image, and determining a target brightness value of each LED lamp bead;

Determine a compensation coefficient for each LED lamp bead according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each collected image, and the compensation time of each collected image, wherein the compensation coefficient is proportional to the increase in brightness required when the corresponding LED lamp bead reaches the target brightness value;

When the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, updating the compensation coefficient of the first LED lamp bead to the coefficient threshold, wherein the first LED lamp bead is any lamp bead in the LED display screen;

The obtained compensation coefficient is sent to the control chip, so that the control chip performs brightness compensation on the corresponding LED lamp beads based on the compensation coefficient, and the control chip is located in the LED display screen.

In a second aspect, an embodiment of the present application further provides a brightness compensation device, including:

An image acquisition unit, used to acquire a plurality of acquired images, wherein the plurality of acquired images include images acquired from a display screen of an LED display screen with a set grayscale, and the compensation times of the plurality of acquired images are all different;

A brightness determination unit, used to obtain a first brightness value of each LED lamp bead in the LED display screen in each collected image, and to determine a target brightness value of each LED lamp bead;

A coefficient determination unit, used to determine the compensation coefficient of each LED lamp bead according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each collected image, and the compensation time corresponding to each collected image, wherein the compensation coefficient is proportional to the increase in brightness required when the LED lamp bead reaches the target brightness value;

A coefficient modification unit, configured to update the compensation coefficient of a first LED lamp bead to the coefficient threshold when the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, wherein the first LED lamp bead is any lamp bead in the LED display screen;

The coefficient sending unit is used to send the obtained compensation coefficient to the control chip so that the control chip can perform brightness compensation on the corresponding LED lamp beads based on the compensation coefficient. The control chip is located in the LED display screen.

In a third aspect, an embodiment of the present application further provides a brightness compensation device, including:

one or more processors;

A memory for storing one or more programs;

When the one or more programs are executed by the one or more processors, the one or more processors implement the brightness compensation method as described in the first aspect.

In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the brightness compensation method as described in the first aspect.

In one embodiment of the present application, multiple captured images including a display screen of an LED display screen are acquired, and the LED display screens in the multiple captured images all use a set grayscale and correspond to different compensation times. Then, a first brightness value of each LED lamp bead in the LED display screen in each captured image is acquired and a target brightness value of each LED lamp bead is determined. The compensation coefficient of each LED lamp bead is determined in combination with the target brightness value, the first brightness value of the LED lamp bead in each captured image, and the compensation time corresponding to each captured image. The currently determined compensation coefficient is proportional to the increase in brightness required for the LED lamp bead to reach the target brightness value. When the compensation coefficient of the first LED lamp bead in each LED lamp bead is greater than a coefficient threshold, the compensation coefficient of the first LED lamp bead is updated to the coefficient threshold. Then, the compensation coefficient of each LED lamp bead is sent to a control chip corresponding to the LED lamp bead in the LED display screen, so that the control chip performs brightness compensation on the LED lamp bead based on the compensation coefficient. This technical means solves the technical problem in the related art that there are differences in the brightness displayed by each LED lamp bead of the LED display screen. Based on the target brightness value, the actual first brightness value of each LED lamp bead, and the corresponding compensation time of each LED lamp bead in each captured image, a suitable compensation coefficient is determined for each LED lamp bead, so that when the LED lamp bead is compensated for brightness by the compensation coefficient, the brightness displayed by each LED lamp bead reaches the target brightness value, that is, the actual brightness of each LED lamp bead is kept as consistent as possible, and the compensation coefficient can be proportional to the increase in the brightness of the LED lamp bead as much as possible. By setting the coefficient threshold, the range of the compensation coefficient can be ensured to be within the normal use range of the hardware equipment of the LED display screen, avoiding overflow, so that the uniformity of the LED display screen (that is, the actual brightness of each LED lamp bead is consistent) and the compensation coefficient are balanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a correction system provided by an embodiment of the present application;

FIG2 is a flow chart of a brightness compensation method provided by an embodiment of the present application;

FIG3 is a flow chart of a brightness compensation method provided by an embodiment of the present application;

FIG4 is a schematic structural diagram of a brightness compensation device provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of the structure of a brightness compensation device provided in one embodiment of the present application.

Detailed ways

The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only the parts related to the present application, rather than all structures, are shown in the accompanying drawings.

The embodiment of the present application provides a brightness compensation method, which can be performed by a brightness compensation device. The brightness compensation device can be implemented by software and/or hardware. Currently, the brightness compensation device can be a computer device with data processing function, such as a desktop computer, a laptop computer, a tablet computer, a mobile phone and other computer devices. The brightness compensation device can be composed of two or more physical entities, or it can be composed of one physical entity.

In an embodiment of the present application, the brightness compensation method is applicable to a correction system, which includes an image acquisition device, a brightness compensation device, and an LED display screen. The correction system is used to determine a compensation coefficient related to brightness when the LED display screen is imaged, and apply the compensation coefficient to the LED display screen to achieve brightness compensation for the LED display screen. In the correction system, the brightness compensation device communicates with the LED display screen and the image acquisition device respectively.

Among them, the LED display screen refers to the LED display screen for which the parameters required for brightness compensation need to be determined. The LED display screen can be an independent display, such as a billboard, etc., or it can be integrated into electronic devices, such as mobile phones, televisions, interactive tablets and other electronic devices equipped with display screens.

In one embodiment, an LED display screen is integrated into an interactive tablet as an example. The interactive tablet is an integrated device that uses touch technology to control the content displayed on the display tablet and realize human-computer interaction, and integrates one or more functions such as a projector, an electronic whiteboard, a screen, a sound system, a television, and a video conferencing terminal.

Exemplarily, each LED constituting an LED display screen is recorded as an LED lamp bead. The red, green, and blue light-emitting diodes of each LED lamp bead are packaged in a lamp holder, and the three primary optical colors (red, green, and blue) of each lamp bead can be used as a pixel of the LED display screen. After the three primary optical colors are mixed, they form the colors that can be displayed by the LED display screen, that is, the colors displayed as pixels.

The brightness of each LED bead can be adjusted to adjust the brightness of the LED display. Generally speaking, when the LED display is displayed, the brightness of each LED bead is set to be consistent. However, due to the discreteness of the LED bead, the actual brightness displayed by each LED bead is different. Therefore, it is necessary to perform brightness compensation on each LED bead based on the actual brightness displayed by each LED bead. The purpose of brightness compensation is to make the actual display brightness of each LED bead consistent.

In one embodiment, the LED display screen further includes a chip for controlling LED lamp beads. Currently, the chip of the LED lamp beads is recorded as a control chip.

Optionally, there may be one or more control chips. When there are multiple control chips, each control chip can control a group of LED lamp beads, that is, the LED lamp beads in the LED display are grouped in advance, and the grouping rules are not currently limited. Each group of LED lamp beads corresponds to a control chip. Alternatively, when there are multiple control chips, each control chip can control a row or a column of LED lamp beads, that is, a control chip is set for each row or column of LED lamp beads in the LED display.

During the operation of the control chip, the LED lamp beads can be controlled to be turned off and on, as well as various parameters used when the LED lamp beads are turned on.

The type of LED display screen is not limited in the embodiment. For example, the LED display screen is a COB display screen. Among them, the COB display screen is a new type of LED display screen. The COB display screen integrates LED chips into a printed circuit board (PCB), without soldering them one by one in the PCB.

Exemplarily, the brightness compensation device and the LED display screen may be different physical entities. In this case, the brightness compensation device and the LED display screen may perform data transmission via a wired or wireless connection, such as the brightness compensation device sending a compensation coefficient to the LED display screen.

Optionally, the brightness compensation device and the LED display screen may also be integrated into the same physical entity. In this case, the brightness compensation device determines the compensation coefficient when performing brightness compensation on the LED display screen installed on itself.

In the embodiment of the present application, the brightness compensation device and the LED display screen are described as different physical entities.

The image acquisition device can be understood as a device with a shooting function, such as a camera, a webcam, a mobile phone, etc. The camera can be an industrial camera or a civilian camera, and the specific category is not limited. For ease of understanding, the image acquisition device is described as a camera as an example.

Optionally, the brightness compensation device and the camera are different physical entities. In this case, the brightness compensation device and the camera can perform data transmission via a wired or wireless connection, such as the brightness compensation device controlling the camera to take pictures.

Optionally, the brightness compensation device and the camera may also be integrated into the same physical entity, that is, the brightness compensation device uses the camera installed on itself to take pictures.

In the embodiment of the present application, description is made by taking the brightness compensation device and the camera as different physical entities.

FIG1 is a schematic diagram of the structure of the correction system. Referring to FIG1 , the brightness compensation device 11 is connected to the LED display screen 12 and the camera 13 respectively. During the operation of the brightness compensation device 11, the camera 13 is controlled to shoot. When the camera 13 shoots, it mainly shoots the display screen of the LED display screen 12. The brightness compensation device 11 obtains the image captured by the camera 13, and then realizes the brightness compensation of the LED display screen based on the acquired image.

FIG. 2 is a flow chart of a brightness compensation method provided by an embodiment of the present application. Referring to FIG. 2 , the brightness compensation method performed during the operation of the brightness compensation device includes:

Step 110, obtaining a plurality of captured images, wherein the plurality of captured images include images captured from a display screen of an LED display screen with a set grayscale, and compensation times of the plurality of captured images are all different.

For example, the control chip in the LED display screen uses pulse width modulation technology (PWM) to control each LED lamp bead, that is, PWM is used to control the on and off time of each LED lamp bead within the display cycle (which can also be understood as the cycle of the PWM wave) to achieve the purpose of controlling the brightness of each LED lamp bead.

For example, when the PWM wave is at a high level, the LED lamp bead is turned on; when the PWM wave is at a low level, the LED lamp bead is turned off. By using the short-term visual persistence effect, the duration of the high level can be adjusted to adjust the brightness of the LED lamp bead. Generally speaking, the longer the duration of the high level, the brighter the actual brightness of the LED lamp bead.

For example, when determining the parameters required for brightness compensation, the LED display screen is first displayed, and the actual brightness difference of each LED lamp bead can be clearly seen through the actual display screen of the LED display screen.

In order to ensure the brightness compensation effect, the LED display screen is controlled to display a pure color image, that is, each LED lamp bead in the LED display screen presents a uniform color. For example, since each LED lamp bead has red, green, and blue light-emitting diodes, and the three light-emitting diodes may have differences in actual display brightness, the compensation coefficients corresponding to the LED lamp bead under the three primary colors are determined based on the three light-emitting diodes corresponding to the three optical primary colors in the LED lamp bead in the embodiment.

In one embodiment, the LED display screen is controlled to display a pure color image (ie, the display screen of the LED display screen is a pure color image). The pure color image includes a red image, a green image, and a blue image, and the LED lamp beads have a corresponding compensation coefficient under each color (ie, pure color).

For example, the LED display screen is controlled to display a pure red image (i.e., a red image) based on the red light-emitting diodes of each LED lamp bead, so as to determine the difference in the actual display brightness of each red light-emitting diode, and then determine the compensation coefficient corresponding to each red light-emitting diode. Similarly, a pure green image (i.e., a green image) and a pure blue image (i.e., a blue image) are displayed to respectively determine the compensation coefficient corresponding to each green light-emitting diode and the compensation coefficient corresponding to each blue light-emitting diode.

Since the compensation coefficients corresponding to the three colors are determined in the same manner, one color is used as an example for description in the embodiment. For example, currently, red is used as an example for description, and at this time, the LED lamp beads mentioned later can all be considered as red light-emitting diodes in the LED lamp beads.

Optionally, when the LED display screen displays a pure color image, the brightness compensation device may send the pure color image to the LED display screen to control the LED display screen to display the pure color image, or the user may control the LED display screen to display the pure color image in other ways, which is not currently limited.

Exemplarily, the brightness of the LED display can be reflected by grayscale, that is, the degree of fineness of the LED lamp beads when adjusting the brightness is the grayscale of the LED display. The grayscale of the LED display is not limited in the embodiment. For example, the LED display can adopt 16-level grayscale or 256-level grayscale. The grayscale can reflect the different color levels of each color between the darkest and the brightest. Based on the grayscale, the grayscale of the LED display can be determined. Among them, the grayscale indicates the current display brightness and darkness. The higher the grayscale, the closer it is to white, and the lower the grayscale, the closer it is to black.

In one embodiment, the grayscale of the current LED display screen is a preset fixed value, and does not change during the execution of the brightness compensation method, that is, the grayscale of each LED lamp bead in the LED display screen is consistent with the set grayscale. The specific value of the set grayscale can be flexibly selected according to the actual needs of the LED display screen.

Optionally, the grayscale of the LED display is adjusted to a set grayscale by modifying the Gamma table of the LED display. The parameters in the Gamma table are used to characterize the brightness response characteristics of the display. Optionally, the grayscale of the LED display is adjusted to a set grayscale by sending instructions to the LED display. The control chip of the LED display is used to receive instructions from the control software and control the LED lamp beads based on the received instructions, such as the control chip sets the LED lamp beads to the set grayscale based on the instructions of the control software. Currently, the control software is installed in the brightness compensation device and is used to control the LED display.

For example, in order to make the actual display brightness of each LED lamp bead consistent, the LED display screen can be subjected to low gray correction and high gray correction. Among them, low gray refers to the low grayscale segment, such as the 0-255 grayscale level (also called grayscale), and the 0-100 grayscale level can be considered as a low grayscale segment. Low gray correction refers to correcting the low grayscale segment of the LED display screen so that the display effect of each LED lamp bead in the low grayscale segment is consistent (such as the actual display brightness is consistent). High correction is similar to low gray correction, which will not be described in detail at present.

In one embodiment, since the brightness displayed by each LED lamp bead at low brightness (also understood as the low gray stage) may be greatly different, therefore, in the embodiment of the present application, the compensation coefficient determined based on the brightness compensation method is the compensation coefficient required for low gray correction, that is, the gray value of the set gray of each LED lamp bead in the LED display screen is less than the gray threshold, and the gray threshold can be understood as the maximum gray value in the low gray segment. For example, when the gray level of 0-100 is the low gray segment, the gray threshold is 100. It can be understood that the gray threshold can also be set to other values, and the embodiment does not limit this.

In one embodiment, in order to achieve a better effect of low gray correction, the high gray correction is turned off when the LED display screen is displayed. At this time, the LED display screen does not use the high gray correction compensation coefficient during the display process. The high gray correction compensation coefficient is the compensation coefficient used when performing high gray correction.

Exemplarily, the compensation time can be understood as the compensation time for the high level in the PWM wave, that is, the compensation time when the LED lamp bead is in the on stage. It can be understood that when the brightness of the LED lamp bead is adjusted by adjusting the duration of the high level in the PWM wave, the duration of the high level in the PWM wave corresponding to each LED lamp bead should be the same. However, due to the difference in the actual brightness of each LED lamp bead, the high level in the PWM wave corresponding to each LED lamp bead can be compensated (that is, the duration of the high level is changed to the duration after adding the compensation time) to make the brightness of each LED lamp bead consistent. At present, the compensation coefficient can also be understood as the compensation time, but in the execution process of the brightness compensation method, the compensation time has been pre-set for the LED lamp bead. Therefore, in order to distinguish it from the pre-set compensation time, the current actual determined compensation time is recorded as the compensation coefficient. In one embodiment, when determining the compensation coefficient, the compensation time of each LED lamp bead of the LED display screen is first set to the same compensation time, that is, when the LED display screen is displayed, the compensation time of each LED lamp bead is the same.

In one embodiment, during the display process of the LED display screen, the compensation time currently used is continuously adjusted, and the brightness compensation device obtains images containing the display screen of the LED display screen at different compensation times, so as to determine the brightness of each LED lamp bead at different compensation times based on the image.

The specific value of the compensation time used by the LED display screen can be preset or calculated according to a set rule.

In one embodiment, the compensation time starts from zero and increases according to a set step length, and after each increment, the LED display screen is photographed by a camera. The set step length can be understood as the amplitude of each increase in the compensation time. The larger the set step length, the larger the amplitude of each increase in the compensation time. After the compensation time increases according to the set step length, an arithmetic progression relationship can be satisfied. The specific value of the set step length can be set according to actual conditions.

During the display process of the LED display, the compensation time is first set to zero, and then the LED display increases according to the set step length. For example, if the step length is set to d (in nanoseconds), during the display process of the LED display, the compensation time is set to 0, d, 2d, 3d, ... in sequence.

Optionally, the number of increments of the compensation time is preset, and the number of increments is a preset number value, which can be understood as the number of times the compensation time is increased. For example, when the target number is 2, the compensation time is incremented 2 times from zero. At this time, there are 3 compensation times in total. The brightness compensation device can obtain an image containing the display screen of the LED display at each compensation time. It should be noted that the method of modifying the compensation time of the LED display is currently not limited.

At present, the image containing the display screen of the LED display screen obtained by the brightness compensation device is recorded as a captured image. Generally speaking, the number of captured images is related to the number of compensation times. For example, when three compensation times are used to determine the compensation coefficient, then there are three captured images, and each captured image corresponds to a compensation time. At this time, the compensation time corresponding to each LED lamp bead in the captured image is the compensation time corresponding to the captured image. In other words, the compensation time of the same LED lamp bead in different captured images is different, and the compensation time of multiple captured images is different. Generally speaking, the number of captured images is at least three, that is, the compensation time is at least three.

Exemplarily, when the LED display screen displays a pure color image based on a compensation time, the brightness compensation device controls the camera to shoot to obtain a captured image corresponding to the pure color image. Afterwards, after the LED display screen modifies the compensation time, the brightness compensation device shoots with the camera again to obtain a captured image corresponding to the pure color image. In an optional manner, the compensation time of multiple captured images increases according to the image acquisition sequence, that is, the compensation time corresponding to two captured images adjacent in the acquisition sequence is in an increasing relationship from front to back. In one embodiment, when the compensation time increases according to a set step length, for two captured images adjacent in the acquisition sequence among the multiple captured images, the difference between the compensation time of the latter captured image and the compensation time of the previous captured image is the set step length.

It should be noted that in actual application, the LED display screen displays red, green and blue images respectively based on a compensation time, and the camera takes three photos based on the three pure color images. Afterwards, the LED display screen displays red, green and blue images respectively based on another compensation time, and the camera takes three photos based on the three pure color images, and so on. Afterwards, based on each image of the same pure color, the compensation coefficient corresponding to the LED lamp bead under that color is determined.

Optionally, the camera transmits each captured image to the brightness compensation device, or the camera transmits all captured images to the brightness compensation device together after capturing all captured images. Currently, there is no limitation on the way the camera transmits captured images.

It is understandable that in actual applications, the LED lamp bead may also include only two colors of LEDs or only one color of LEDs. No matter how many colors of LEDs the LED lamp bead contains, the method for determining the compensation coefficient of each color of LED is the same.

Step 120: Obtain a first brightness value of each LED lamp bead in the LED display screen in each collected image, and determine a target brightness value of each LED lamp bead.

The first brightness value is the brightness value actually displayed by the LED lamp bead. Each LED lamp bead has a corresponding first brightness value in each captured image. The first brightness value can reflect the actual display brightness of the corresponding LED lamp bead at the compensation time corresponding to the captured image.

It is understandable that since the LED lamp beads in each collected image have the same set grayscale, only the set compensation time is different. Therefore, the main reason why the first brightness value of the same LED lamp bead in each collected image is different is due to the different compensation time.

The brightness value can be understood as the specific value of the brightness. It can be understood that the brightness and color actually displayed by each LED lamp bead can be reflected by the pixels corresponding to the LED lamp bead in the collected image. Therefore, after obtaining each collected image, the first brightness value of each LED lamp bead in the corresponding collected image can be determined.

It should be noted that determining the brightness value of LED lamp beads in an LED display screen through an image containing the display screen of the LED display screen is a technical means that has been realized and will not be explained separately at present.

The target brightness value refers to the brightness value that each LED lamp bead is expected to achieve. When each LED lamp bead uses the same target brightness value, that is, when the actual brightness of each LED lamp bead reaches the target brightness value, the brightness of each LED lamp bead can be consistent in the low gray stage.

The target brightness value may be a preset brightness value, or a brightness value artificially specified in combination with the first brightness value of each current LED lamp bead in each captured image, or a brightness value calculated by a brightness compensation device according to a set rule.

In one embodiment, the target brightness value of each LED lamp bead is determined by collecting images. For example, after the brightness compensation device determines the first brightness value of each LED lamp bead, a reasonable target brightness value is obtained by combining the first brightness value settings. In one embodiment, determining the target brightness value of each LED lamp bead in this step may include steps 121-122:

Step 121: Select a target image from each collected image.

The target image refers to the acquired image used when determining the target brightness value.

Exemplarily, one image is randomly selected from each acquired image as the target image; or, after removing the acquired image with the shortest compensation time and the acquired image with the longest compensation time from each acquired image, one image is selected as the target image; or, a specific acquired image is selected as the target image according to a pre-set rule.

For example, each time the compensation time increases, the brightness compensation device controls the camera to shoot the LED display screen. At this time, the captured image obtained by the second shooting is selected as the target image, that is, the captured image with the second shortest compensation time is selected as the target image.

Step 122: Obtain the first brightness value of each LED lamp bead in the target image, and use the average value of each first brightness value as the target brightness value of each LED lamp bead.

After determining the target image, the first brightness value of each LED lamp bead under the target image can be determined, and then the target brightness value is determined based on the first brightness value of each LED lamp bead.

In one embodiment, the average value of the first brightness values of each LED lamp bead in the target image is calculated and used as the target brightness value. It can be understood that the average value of the first brightness value can best reflect the average brightness displayed by each LED lamp bead.

It should be noted that in actual applications, the target brightness value may also be determined in other ways, such as selecting the first brightness value with the largest number of occurrences from among the first brightness values corresponding to the selected target image as the target brightness value.

Thereafter, step 130 is executed.

Step 130, determine the compensation coefficient of each LED lamp bead according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each collected image, and the compensation time corresponding to each collected image. The compensation coefficient is proportional to the increase in brightness required when the LED lamp bead reaches the target brightness value.

Exemplarily, after determining the target brightness value and the first brightness value of each LED lamp bead in each captured image, the compensation coefficient required for each LED lamp bead to reach the target brightness value is determined.

It can be understood that the compensation coefficient is a compensation coefficient for the low gray stage, and is used for the low gray correction process of the LED display.

The compensation coefficients of the LED lamp beads in the embodiments of the present application are determined in the same manner. For ease of understanding, the following description is made by taking the determination of the compensation coefficient of one LED lamp bead as an example.

Exemplarily, the LED display screen is displayed at a low grayscale, and the LED lamp beads have a brightness value. On this basis, after the LED lamp beads are brightness compensated (i.e., the compensation time is set for the LED lamp beads), the brightness of the LED lamp beads increases, that is, the brightness value of the LED lamp beads increases. At this time, the difference between the current brightness value of the LED lamp beads and the original brightness value of the LED lamp beads can be considered as the increase in brightness based on the compensation time. Moreover, the longer the compensation time, the greater the increase in brightness, that is, the compensation time is proportional to the increase in brightness. Based on the above description, it can be seen that the compensation time and the compensation coefficient have the same effect, so the compensation coefficient is also proportional to the increase in the brightness of the LED lamp beads.

Based on the proportional relationship, combined with each first brightness value of the LED lamp bead, the target brightness value and the compensation time corresponding to each captured image (which can also be understood as the compensation time corresponding to each first brightness value), the compensation coefficient required for the LED lamp bead to reach the target brightness value can be determined. It can be understood that the compensation coefficient is proportional to the increase in brightness required when the corresponding LED lamp bead reaches the target brightness value, that is, when the LED lamp bead reaches the target brightness value, if a larger value of brightness increase is required, the required compensation coefficient is larger, otherwise, the required compensation coefficient is smaller.

For example, in combination with the target brightness value of the LED lamp bead and the first brightness value of the LED lamp bead in each collected image (which can also be understood as each compensation time), a first brightness value is selected for the LED lamp bead. In the embodiment, the selected first brightness value is recorded as the second brightness value, and the second brightness value is a first brightness value that is less than and only less than the target brightness value (that is, only smaller than the target brightness value). In this case, the first brightness value that is only greater than the second brightness value is also the first brightness value that is only greater than or equal to the target brightness value. For example, the second brightness value is recorded as B(N-2), and the first brightness value that is only greater than or equal to the target brightness value is recorded as B(N-1). At this time, B(N-2) and B(N-1) are the first brightness values in two adjacent collected images in the collection order, and B(N-2)＜target brightness value≤B(N-1). In other words, it can be considered that the target brightness value is located in the brightness range composed of B(N-2) and B(N-1).

It can be understood that the LED lamp bead can reach the target brightness value most quickly by increasing a smaller compensation time at the second brightness value. Therefore, on the basis of the compensation time corresponding to the second brightness value, an additional compensation time required for the second brightness value to reach the target brightness value is added, and the compensation coefficient required for the LED lamp bead to reach the target brightness value can be obtained.

The increased compensation time can be determined based on the relationship that the compensation time is proportional to the increase in the brightness of the LED lamp bead.

For example, the brightness difference between the target brightness value and B(N-2) is determined, and the brightness difference can be understood as the increase in brightness of the LED lamp bead when it increases from B(N-2) to the target brightness value. At the same time, the brightness increase value corresponding to the set step length is determined, that is, the increase in brightness of the LED lamp bead when the compensation time is the set step length. Since the difference in compensation time between the latter acquired image and the previous acquired image in two adjacent acquired images in the acquisition sequence is the set step length, the difference in the first brightness value of the LED lamp bead in the latter acquired image and the previous acquired image can be understood as the brightness increase value corresponding to the set step length. For example, the brightness difference between B(N-1) and B(N-2) can reflect the increase in brightness of the LED lamp bead when the compensation time corresponding to B(N-2) increases to the compensation time corresponding to B(N-1), that is, the brightness increase value corresponding to the set step length.

Afterwards, based on the proportional relationship between the compensation time and the increase in the brightness of the LED lamp bead, combined with the brightness increase value corresponding to the set step size, and the brightness difference between the target brightness value and B(N-2), the compensation time required for the LED lamp bead to increase from B(N-2) to the target brightness value can be determined.

Afterwards, this compensation time is added to the compensation time corresponding to B(N-2) to obtain the compensation coefficient required for the LED lamp bead to reach the target brightness value.

Optionally, when there is no first brightness value that is just less than the target brightness value, that is, the first brightness value of the LED lamp bead in each captured image is greater than or equal to the target brightness value, then the compensation coefficient of the LED lamp bead can be set to zero, that is, there is no need to compensate the LED lamp bead, and the actual brightness of the LED lamp bead can reach the target brightness value.

Optionally, when there is no first brightness value that is only greater than or equal to the target brightness value, that is, when the first brightness value of the LED lamp bead in each collected image is less than the target brightness value, the currently used maximum compensation time (that is, the compensation time corresponding to the last collected image taken) can be directly used as the compensation coefficient of the LED lamp bead to make the LED lamp bead as close to the target brightness value as possible.

It can be understood that when the first brightness value of the LED lamp bead in each collected image is less than the target brightness value, even if the maximum compensation time is used as the compensation coefficient, the LED lamp bead cannot reach the target brightness value, which will reduce the effect of brightness compensation. Based on this, in order to make the LED lamp bead reach the target brightness value, the compensation time can be increased by increasing the number of collected images, so that the first brightness value of the LED lamp bead in the collected image corresponding to the maximum compensation time is greater than or equal to the target brightness value. Alternatively, the incremental increase of the compensation time can be increased by increasing the value of the set step length, so that the first brightness value of the LED lamp bead in the collected image corresponding to the maximum compensation time is greater than or equal to the target brightness value.

When the compensation time is continuously increased to increase the number of collected images, although the compensation coefficient that enables the LED lamp beads to reach the target brightness value can be calculated, when the LED display screen is displayed at low grayscale, the brightness of the camera photo is relatively low, and the required exposure time and shooting time are relatively long. Therefore, when the number of collected images is increased, the required shooting time will also increase. For example, when the camera shoots an image, the average exposure time of an image is 40s. Then, it takes 2 minutes for the camera to shoot three pure color images corresponding to the three optical primary colors. In this way, for each additional collected image (which can also be understood as increasing the compensation time), the shooting time will be increased by 2 minutes. In addition, the time spent setting the compensation time for the LED display screen will increase the time required for the compensation coefficient determination process, which is not conducive to the rapid determination of the compensation coefficient.

When the value of the set step length is increased, although the compensation coefficient that enables the LED lamp beads to reach the target brightness value can be calculated, after the set step length is increased, the compensation time that increases incrementally according to the set step length will also become longer. In this way, the increase value of the first brightness value of the LED lamp beads in adjacent collected images will also increase, and the target brightness value determined based on the collected image will also increase, that is, the range of the compensation coefficient is expanded, which reduces the accuracy of the compensation coefficient.

Therefore, the method of continuously increasing the compensation time to increase the number of collected images and the method of increasing the value of the set step length are not conducive to the determination of the compensation coefficient. Based on this, in order to avoid the situation where the LED lamp beads still cannot reach the target brightness value when the maximum compensation time is used as the compensation coefficient to compensate the LED lamp beads, in the embodiment, an additional compensation time is calculated in combination with the target brightness value and the maximum first brightness value of the LED lamp beads in each collected image, and the calculated compensation time is added to the maximum compensation time to obtain the final compensation coefficient, thereby ensuring that the final compensation coefficient can make the LED lamp beads reach the target brightness value.

Among them, the additionally calculated compensation time is similar to the calculation method of the aforementioned compensation time. For example, the brightness difference between the target brightness value and the maximum first brightness value of the LED lamp bead is determined, and the brightness increase value corresponding to the set step size is determined. The brightness increase value can be the brightness difference between the maximum first brightness value of the LED lamp bead and the second largest first brightness value. Then, according to the relationship that the compensation time is proportional to the increase value of the brightness of the LED lamp bead, combined with the brightness increase value corresponding to the set step size, and the brightness difference between the target brightness value and the maximum first brightness value of the LED lamp bead, the compensation time required for the maximum first brightness value to increase to the target brightness value can be determined. Then, the compensation time is added to the compensation time corresponding to the maximum first brightness value (i.e., the maximum compensation time) to obtain the compensation coefficient.

After the compensation coefficient of the LED lamp bead is determined, step 140 is executed.

Step 140: When the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, the compensation coefficient of the first LED lamp bead is updated to the coefficient threshold. The first LED lamp bead is any lamp bead in the LED display screen.

It is understandable that when the control chip of the LED display controls the display of the LED lamp beads, due to the limitations of the hardware equipment (i.e. the hardware conditions of the control chip), there is a maximum compensation time limit when compensating the brightness of the LED lamp beads. If the compensation time when compensating the LED lamp beads exceeds the maximum compensation time limit, the compensation time overflow will occur, which will cause the LED lamp beads to light up abnormally.

In order to avoid overflow, the coefficient threshold of the compensation coefficient is set. The coefficient threshold can be determined according to the model of the control chip actually used by the LED display. Generally speaking, the coefficient threshold is greater than the maximum compensation time when the compensation time is incremented according to the set step length, and is within the limit of the maximum compensation time of the control chip. The coefficient threshold can be understood as the maximum compensation coefficient that can be used when the current LED display is compensated.

After determining the compensation coefficient of the LED lamp bead, compare the compensation coefficient with the coefficient threshold. If the compensation coefficient is less than or equal to the coefficient threshold, it means that there is no overflow. At this time, retain the compensation coefficient as the compensation coefficient of the LED lamp bead. If the compensation coefficient is greater than the coefficient threshold, it means that there may be an overflow. At this time, use the coefficient threshold as the compensation coefficient of the LED lamp bead, that is, modify the compensation coefficient of the LED lamp bead to the coefficient threshold. Currently, for ease of description, the LED lamp bead whose compensation coefficient determined in step 130 is greater than the coefficient threshold is recorded as the first LED lamp bead. It should be noted that when the coefficient threshold is used to compensate the first LED lamp bead, the deviation of the compensation coefficient being proportional to the increase in brightness can be made very small, that is, the deviation between the actual brightness of the first LED lamp bead and the target brightness value is very small.

Optionally, when the target brightness value is greater than each first brightness value of the LED lamp bead, the determined compensation coefficient is compared with the coefficient threshold. Because, when there is a first brightness value greater than the target brightness value, it means that the LED lamp bead can reach the target brightness value based on the currently used compensation time, and there will be no overflow.

Step 150: Send the obtained compensation coefficient to the control chip, so that the control chip performs brightness compensation on the corresponding LED lamp beads based on the compensation coefficient. The control chip is located in the LED display screen.

Exemplarily, after the brightness compensation device determines the final compensation coefficient of each LED lamp bead, it sends it to the control chip in the LED display screen, so that the control chip of the LED display screen applies the compensation coefficient to perform brightness compensation based on the compensation coefficient during the display process, that is, the control chip of the LED display screen adjusts the duration of the high level of the PWM wave based on the compensation coefficient, thereby realizing brightness compensation for the LED lamp beads.

Optionally, when there are multiple control chips, when the brightness compensation device transmits data with the control chip (when the brightness compensation device transmits data with the LED display screen, it mainly transmits data with the control chip), the LED lamp beads controlled by each control chip can be determined. Then, after determining the compensation coefficient of each LED lamp bead, the compensation coefficient can be sent to the control chip corresponding to the LED lamp bead to control the LED lamp bead.

In one embodiment of the present application, multiple captured images including the display screen of an LED display screen are acquired, and the LED display screens in the multiple captured images all use a set grayscale and correspond to different compensation times. Then, a first brightness value of each LED lamp bead in the LED display screen in each captured image is acquired and a target brightness value of each LED lamp bead is determined. The compensation coefficient of each LED lamp bead is determined by combining the target brightness value, the first brightness value of the LED lamp bead in each captured image, and the compensation time corresponding to each captured image. The currently determined compensation coefficient is proportional to the increase in brightness required for the LED lamp bead to reach the target brightness value. When the compensation coefficient of the first LED lamp bead among the LED lamp beads is greater than the coefficient threshold, the compensation coefficient of the first LED lamp bead is modified to the coefficient threshold. Then, The compensation coefficient of each LED lamp bead is sent to the control chip corresponding to the LED lamp bead in the LED display screen, so that the control chip can compensate the brightness of the LED lamp bead based on the compensation coefficient. The technical means solves the technical problem that the brightness displayed by each LED lamp bead of the LED display screen in the related art is different. Based on the target brightness value, the actual first brightness value of each LED lamp bead and the corresponding compensation time of each LED lamp bead in each collected image, a suitable compensation coefficient is determined for each LED lamp bead, so that when the LED lamp bead is compensated for the brightness by the compensation coefficient, the brightness displayed by each LED lamp bead reaches the target brightness value, that is, the actual brightness of each LED lamp bead is kept as consistent as possible, and the compensation coefficient can be proportional to the increase in the brightness of the LED lamp bead as much as possible. By setting the coefficient threshold, the range of the compensation coefficient can be ensured to be within the normal use range of the hardware equipment of the LED display screen, avoiding the overflow phenomenon, so that the uniformity of the LED display screen (that is, the actual brightness of each LED lamp bead is consistent) and the compensation coefficient are balanced. In addition, the target brightness value is determined by the average value of the first brightness value of each LED lamp bead in a collected image, which can ensure that the determined target brightness value is consistent with the actual lighting of the LED lamp bead.

FIG3 is a flow chart of a brightness compensation method provided by an embodiment of the present application. The brightness compensation method is based on the above brightness compensation method and exemplarily describes the process of determining the compensation coefficient. Referring to FIG3 , the brightness compensation method includes:

Step 210: Acquire a plurality of collected images, wherein the plurality of collected images include images collected from a display screen of an LED display screen with a set grayscale, and the compensation times of the plurality of collected images are all different.

Exemplarily, the compensation time starts from zero and increases according to a set step size.

In one embodiment, the number of times the compensation time is incremented is a preset target number. For example, assuming that N acquisition images are currently taken, N ≥ 3, and the set step size used when the compensation time is incremented is d (in nanoseconds), at this time, the compensation time corresponding to the first acquisition image taken is 0, the compensation time corresponding to the second acquisition image is d, ..., and the compensation time corresponding to the Nth acquisition image is d*(N-1), that is, the target number is N-1.

Step 220: Obtain the first brightness value of each LED lamp bead in the LED display screen in each collected image.

Step 230: Select a target image from each of the acquired images.

Exemplarily, the captured image currently used to determine the target brightness value is used as the target image. Optionally, the compensation time corresponding to the target image is short, which can ensure the accuracy of the compensation coefficient. In one embodiment, the second captured image is selected as the target image for description.

Step 240: Obtain the first brightness value of each LED lamp bead in the target image, and use the average value of each first brightness value as the target brightness value of each LED lamp bead.

Step 250: determine the second brightness value of each LED lamp bead according to the first brightness value of each LED lamp bead in each collected image, wherein the second brightness value is the first brightness value among the first brightness values of the corresponding LED lamp bead that is less than and only less than the target brightness value.

In the embodiment, the compensation coefficient of one LED lamp bead is taken as an example for description. In actual application, the compensation coefficient of each LED lamp bead can be determined in this way, and the compensation coefficient of each LED lamp bead can be determined sequentially or simultaneously.

Exemplarily, in N captured images, the first brightness value of the LED lamp bead in the first captured image is recorded as B0, the first brightness value of the LED lamp bead in the second captured image is recorded as B1, ..., and the first brightness value in the Nth captured image is recorded as B(N-1). Since the compensation time is proportional to the increase in the first brightness value, and the compensation time of the first captured image is the smallest, the first brightness values of an LED lamp bead are arranged in the order of B0, B1, ..., B(N-1) from small to large. The second brightness value of the LED lamp bead is selected from each first brightness value.

For example, the relationship between the target brightness value and each first brightness value is determined. In one embodiment, it is first determined whether the target brightness value is less than or equal to B0. If not, it is continued to determine whether the target brightness value is less than or equal to B1, and so on, until it is determined that the target brightness value is less than or equal to a certain first brightness value, the previous first brightness value compared with the target brightness value is determined as a first brightness value that is less than and only less than the target brightness value, and currently, the determined first brightness value is recorded as the second brightness value. For example, when the target brightness value is greater than B1 and less than or equal to B2, B1 is the currently determined second brightness value.

It should be noted that in actual applications, instead of comparing in sequence, the brightness range can be divided based on the first brightness value. For example, less than or equal to B0 is a brightness range, greater than B0 and less than or equal to B1 is a range... greater than B(N-2) and less than or equal to B(N-1) is a brightness range, and greater than B(N-1) is a brightness range. After that, the brightness range to which the target brightness value belongs is determined, and the minimum first brightness value corresponding to the brightness range is used as the second brightness value. For example, if the target brightness value is in the brightness range greater than B(N-2) and less than or equal to B(N-1), the second brightness value is B(N-2).

In one embodiment, there is a case where the target brightness value is less than or equal to the minimum first brightness value of the LED lamp bead, that is, the target brightness value is less than or equal to B0, and at this time, the second brightness value cannot be found. In this case, it also includes: when the minimum first brightness value of the second LED lamp bead in each collected image is equal to or greater than the target brightness value (that is, there is no second brightness value of the second LED lamp bead), the compensation coefficient of the second LED lamp bead is determined to be zero, and the second LED lamp bead is any lamp bead in the LED display screen.

It can be understood that the compensation time corresponding to the minimum first brightness value of the LED lamp bead in each captured image is 0. If the target brightness value is less than and equal to the minimum first brightness value, it means that there is no need to compensate the LED lamp bead, and the actual brightness value of the LED lamp bead can reach the target brightness value. Therefore, the compensation coefficient of the LED lamp bead is determined to be 0, that is, there is no need to compensate the LED lamp bead during the application of the LED display. In one embodiment, for ease of understanding, the LED lamp bead whose minimum first brightness value is equal to or greater than the target brightness value is recorded as the second LED lamp bead, which can also be understood as failing to determine the second brightness value of the second LED lamp bead.

Step 260: Determine the brightness difference between the target brightness value and the second brightness value, and determine the brightness increase value corresponding to the set step size.

Exemplarily, the brightness increase value corresponding to the set step length refers to the increase in the actual brightness value of the LED lamp bead after the compensation time of the LED lamp bead is increased by the set step length. It can be understood that when the compensation time increases according to the set step length, the difference in the first brightness value of the LED lamp bead in the two corresponding adjacent captured images can be understood as the brightness increase value corresponding to the set step length. Optionally, the brightness difference (i.e., brightness increase value) between two first brightness values that are adjacent to each other (can also be understood as the adjacent acquisition order of the captured images) should be the same, and both are the brightness increase values when the set step length is used as the compensation time. Therefore, the brightness difference between any two adjacent first brightness values can be used as the brightness increase value of the set step length.

However, in actual applications, due to the limitations of factors such as LED lamp hardware, the compensation time and the brightness increase value are nearly proportional rather than completely proportional. At this time, in order to ensure the accuracy of the compensation coefficient, the first brightness value and the second brightness value that are only greater than the second brightness value are used to determine the brightness increase value corresponding to the current set step length. For example, if the second brightness value is B0, at this time, the first brightness value that is only greater than the second brightness value is B1, and the brightness increase value corresponding to the set step length is B1-B0.

For example, the brightness difference between the target brightness value and the second brightness value may represent a brightness increase value required to adjust the second brightness value to the target brightness value.

Step 270: Determine the compensation coefficient of the LED lamp beads according to the brightness difference, the brightness increase value, the set step size, and the compensation time of the collected image corresponding to the second brightness value.

Since the compensation time is proportional to the increase in brightness, after knowing the increase in brightness when the step length is set as the compensation time, and the brightness difference between the target brightness value and the second brightness value, the compensation time corresponding to the brightness difference between the target brightness value and the second brightness value can be determined based on the proportional relationship. For example, the second brightness value is B0, the first brightness value that is only greater than the second brightness value is B1, the target brightness value is av, the step length is set to d, and the compensation time corresponding to the brightness difference between the target brightness value and the second brightness value can be expressed as: d*(av-B0)/(B1-B0), and then, the compensation time plus the compensation time corresponding to the second brightness value (that is, the compensation time of the captured image where the second brightness value is located) can obtain the compensation coefficient required for the LED lamp bead to reach the target brightness value.

For example, when the second brightness value is B0, its corresponding compensation time is 0. At this time, the compensation coefficient of the LED lamp bead is 0+d*(av-B0)/(B1-B0). On this basis, it can be deduced that when the second brightness value is B(n-2), the corresponding compensation coefficient can be recorded as d*(n-2)+d(av-B(n-2))/(B(n-1)-B(n-2))=d((n-2)+(av-B(n-2))/(B(n-1)-B(n-2))), where N≥n≥2, and N is the total number of captured images.

In one embodiment, there is a case where the second brightness value is the maximum first brightness value of the corresponding LED lamp bead, and in this case, there is no first brightness value that is only greater than the second brightness value. Therefore, the brightness difference between the second brightness value (i.e., the maximum first brightness value) and the first brightness value that is only less than the second brightness value (i.e., the second largest first brightness value) can be used as the brightness increase value corresponding to the set step size to determine the compensation coefficient of the LED lamp bead. At this time, the compensation coefficient of the LED lamp bead can be expressed as d*(N-1)+d*(av-B(N-1))/(B(N-1)-B(N-2)), where d is the set step size, av is the target brightness value, N is the total number of captured images, d*(N-1) is the compensation time corresponding to the Nth captured image, B(N-1) is the maximum first brightness value (i.e., the first brightness value of the LED lamp bead in the Nth captured image), and B(N-2) is the second largest first brightness value (i.e., the first brightness value of the LED lamp bead in the N-1th captured image).

Step 280: When the second brightness value of the first LED bead is the maximum first brightness value of the first LED bead in each collected image, determine whether the compensation coefficient of the first LED bead is greater than the coefficient threshold. When the compensation coefficient is greater than the coefficient threshold, execute step 290; otherwise, end.

Exemplarily, when the second brightness value selected for the first LED bead is the maximum first brightness value of the first LED bead (i.e., the first brightness value of the LED bead in the last captured image), overflow may occur. Therefore, when the second brightness value is selected and the selected second brightness value is the maximum first brightness value of the LED bead, after the compensation coefficient is determined, it is determined whether the compensation coefficient is greater than the coefficient threshold. If the second brightness value is not the maximum first brightness value, the currently determined compensation coefficient is directly used as the final compensation coefficient of the LED bead.

Step 290: When the compensation coefficient is greater than the coefficient threshold, the compensation coefficient of the first LED lamp bead is updated to the coefficient threshold.

That is, when the compensation coefficient is greater than the coefficient threshold, the compensation coefficient of the first LED lamp bead is determined to be the coefficient threshold. Then, step 2100 is executed.

Step 2100: Send the obtained compensation coefficient to the control chip, so that the control chip performs brightness compensation on the corresponding LED lamp beads based on the compensation coefficient, and the control chip is located in the LED display screen.

The following is an exemplary description of the brightness compensation method provided in the embodiment of the present application. In this example, when the LED display screen displays a pure color image, the compensation time of each LED lamp bead of the LED display screen is first set to 0, and then the high gray correction of the LED display screen is turned off, and the LED display screen is set to a set grayscale (the grayscale is set to a low-order grayscale value) by modifying the Gamma table or sending instructions to the control chip of the LED display screen (also known as a receiving card). Currently, the grayscale setting is 64 as an example for description. At this time, the grayscale of each LED lamp bead is 64. Afterwards, the brightness compensation device controls the camera to shoot the LED display screen.

Currently, the step length is set to d, and d is described as 0.4ns. Under the same pure color image, the camera takes N acquired images. At this time, the compensation time of the first acquired image is 0, the compensation time of the second acquired image is d, the compensation time of the third acquired image is 2d, and so on. Afterwards, the brightness compensation device obtains N acquired images, and obtains the first brightness value of each LED lamp bead in each acquired image. Currently, each LED lamp bead corresponds to N first brightness values. At this time, the first brightness value of the first acquired image is recorded as B0, the first brightness value of the second acquired image is recorded as B1, ..., and the first brightness value of the Nth acquired image is recorded as B(N-1).

Afterwards, the brightness compensation device calculates the average of the first brightness values of each LED lamp bead in the second captured image (compensation time is d) and uses it as the target brightness value. At this time, the target brightness value is recorded as av. Afterwards, the compensation coefficient of each LED lamp bead when it reaches av is determined. At present, the compensation coefficient is recorded as Coef, and the coefficient threshold is recorded as Max. At this time, the compensation coefficient is determined as follows:

According to the above method, the compensation coefficient of each LED lamp bead can be determined. After that, the brightness compensation device sends the compensation coefficient to the control chip of each LED lamp bead in the LED display screen, so that during the display process of the LED display screen, the control chip can perform brightness compensation on the LED lamp bead based on the compensation coefficient. Generally speaking, when three acquisition images are taken, a more accurate compensation coefficient can be obtained and the time consumption is shorter. In addition, when the number of acquired images increases, the target brightness value is more concentrated in the brightness value range corresponding to the first three acquisition images, which avoids overflow and further ensures the accuracy of the compensation coefficient.

In one embodiment of the present application, a plurality of captured images including a display screen of an LED display screen are acquired, and the LED display screens in the plurality of captured images all use a set grayscale and correspond to different compensation times. Then, a target brightness value is determined by combining an average value of the first brightness values of each LED lamp bead in one captured image, and a second brightness value that is only less than the target brightness value is determined by combining the first brightness values of the LED lamp bead in each captured image. Then, a compensation coefficient of the LED lamp bead is determined according to the brightness difference between the target brightness value and the second brightness value, a set step size, a brightness increase value corresponding to the set step size, and a compensation time corresponding to the second brightness value. In addition, the second brightness value selected for the LED lamp bead is the maximum first brightness value of the LED lamp bead and the determined compensation coefficient is greater than When the coefficient threshold is reached, the compensation coefficient of the LED lamp bead is modified to the coefficient threshold, and then the compensation coefficient of each LED lamp bead is sent to the control chip of the LED display screen, so that the control chip can compensate the brightness of the LED lamp bead based on the compensation coefficient. The technical problem of the difference in brightness displayed by each LED lamp bead of the LED display screen in the related technology is solved. The brightness displayed by each LED lamp bead reaches the target brightness value through the compensation coefficient, that is, the actual brightness of each LED lamp bead is kept as consistent as possible, and the compensation coefficient is determined by the ratio of the brightness difference between the target brightness value and the second brightness value to the brightness increase value corresponding to the set step length, so that the compensation coefficient is as proportional to the increase value of the brightness of the LED lamp bead as possible, ensuring the compensation effect. In addition, by setting the coefficient threshold, it can be ensured that the range of the compensation coefficient is within the normal use range of the hardware equipment of the LED display screen, avoiding the overflow phenomenon, so that the uniformity of the LED display screen (that is, the actual brightness of each LED lamp bead is consistent) and the compensation coefficient are balanced.

FIG4 is a schematic diagram of the structure of a brightness compensation device provided by an embodiment of the present application. Referring to FIG4 , the brightness compensation device includes: an image acquisition unit 301 , a brightness determination unit 302 , a coefficient determination unit 303 , a coefficient modification unit 304 and a coefficient sending unit 305 .

Among them, the image acquisition unit 301 is used to acquire multiple captured images, and the multiple captured images include images captured from the display screen of the LED display screen with a set grayscale, and the compensation time of the multiple captured images is different; the brightness determination unit 302 is used to obtain the first brightness value of each LED lamp bead in the LED display screen in each captured image, and determine the target brightness value of each LED lamp bead; the coefficient determination unit 303 is used to determine the compensation coefficient of each LED lamp bead according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each captured image, and the compensation time corresponding to each captured image, and the compensation coefficient is proportional to the increase in brightness required when the LED lamp bead reaches the target brightness value; the coefficient modification unit 304 is used to update the compensation coefficient of the first LED lamp bead to the coefficient threshold when the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, and the first LED lamp bead is any lamp bead in the LED display screen; the coefficient sending unit 305 is used to send the obtained compensation coefficient to the control chip, so that the control chip performs brightness compensation on the corresponding LED lamp bead based on the compensation coefficient, and the control chip is located in the LED display screen.

In one embodiment of the present application, the compensation time of multiple captured images increases in the order in which the images are captured.

In one embodiment of the present application, for two acquired images that are adjacent in acquisition order among the multiple acquired images, the difference between the compensation time of the latter acquired image and the compensation time of the previous acquired image is the set step size.

In one embodiment of the present application, the coefficient determination unit 303 includes: a brightness selection subunit, which is used to determine the second brightness value of each LED lamp bead according to the first brightness value of each LED lamp bead in each collected image, and the second brightness value is the first brightness value that is less than and only less than the target brightness value among the first brightness values of the corresponding LED lamp bead; a brightness calculation subunit, which is used to determine the brightness difference between the target brightness value and the second brightness value, and to determine the brightness increase value corresponding to the set step size; a compensation determination subunit, which is used to determine the compensation coefficient of the LED lamp bead according to the brightness difference, the brightness increase value, the set step size and the compensation time of the collected image corresponding to the second brightness value.

In one embodiment of the present application, it also includes: a zero compensation determination unit, which is used to determine that the compensation coefficient of the second LED lamp bead is zero if the second brightness value of the second LED lamp bead does not exist, and the second LED lamp bead is any lamp bead in the LED display screen.

In one embodiment of the present application, the coefficient modification unit 304 includes: a coefficient judgment subunit, used to judge whether the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold when the second brightness value of the first LED lamp bead is the largest first brightness value of the first LED lamp bead in each collected image; a compensation coefficient modification subunit, used to update the compensation coefficient of the first LED lamp bead to the coefficient threshold when the compensation coefficient is greater than the coefficient threshold.

In one embodiment of the present application, the brightness determination unit 302 includes: a brightness acquisition subunit, used to obtain the first brightness value of each LED lamp bead in the LED display screen in each collected image; an image selection subunit, used to select a target image in each collected image; a mean determination subunit, used to obtain the first brightness value of each LED lamp bead in the target image, and use the average value of each first brightness value as the target brightness value of each LED lamp bead.

In one embodiment of the present application, the display screen of the LED display screen is a pure color image, and the pure color image includes a red image, a green image, and a blue image. The LED lamp beads have a corresponding compensation coefficient under each pure color.

In one embodiment of the present application, the grayscale value of the set grayscale of each LED lamp bead in the LED display screen is less than the grayscale threshold.

The brightness compensation device provided above can be used to execute the brightness compensation method executed by the brightness compensation device provided in any of the above embodiments, and has corresponding functions and beneficial effects.

It is worth noting that in the embodiment of the above-mentioned brightness compensation device, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

FIG5 is a schematic diagram of the structure of a brightness compensation device provided by an embodiment of the present application. As shown in FIG5, the brightness compensation device includes a processor 40 and a memory 41; the number of processors 40 can be one or more, and FIG5 takes one processor 40 as an example. The processor 40 and the memory 41 in the brightness compensation device can be connected via a bus or other means, and FIG5 takes the connection via a bus as an example.

The memory 41, as a computer-readable storage medium, can be used to store software programs, computer executable programs and modules, such as program instructions/modules corresponding to the brightness compensation device in the embodiment of the present application (the image acquisition unit 301, the brightness determination unit 302, the coefficient determination unit 303, the coefficient modification unit 304 and the coefficient sending unit 305 in the brightness compensation device). The processor 40 executes various functional applications and data processing of the brightness compensation device by running the software programs, instructions and modules stored in the memory 41, that is, realizes the above-mentioned brightness compensation method.

The memory 41 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the brightness compensation device, etc. In addition, the memory 41 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some examples, the memory 41 may further include a memory remotely arranged relative to the processor 40, and these remote memories may be connected to the brightness compensation device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

The brightness compensation device may also include a communication device for realizing data communication according to the instructions of the processor, such as data communication with a camera or with an LED display screen. The brightness compensation device may also include an input device and an output device, wherein the input device may be used to receive input digital or character information and generate key signal input related to user settings and function control of the brightness compensation device, and may also include an audio input device such as a microphone. The output device may include devices such as a display screen and a speaker.

The above-mentioned brightness compensation device includes a corresponding brightness compensation device, which can be used to execute the brightness compensation method provided by any embodiment and has corresponding functions and beneficial effects.

An embodiment of the present application further provides a brightness compensation system. Referring to FIG. 1 , the brightness compensation system includes an LED display screen, a camera, and the aforementioned brightness compensation device.

Wherein, when the LED display screen is displayed, the camera is controlled by the brightness compensation device to take pictures to obtain multiple captured images, and the multiple captured images include images captured from the display screen of the LED display screen with a set grayscale, and the compensation time of the multiple captured images is different. After the brightness compensation device obtains the multiple captured images, it obtains the first brightness value of each LED lamp bead in the LED display screen in each captured image, and determines the target brightness value of each LED lamp bead; according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each captured image, and the compensation time corresponding to each captured image, the compensation coefficient of each LED lamp bead is determined, and the compensation coefficient is proportional to the increase in brightness required when the LED lamp bead reaches the target brightness value; when the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, the compensation coefficient of the first LED lamp bead is updated to the coefficient threshold, and the first LED lamp bead is any lamp bead in the LED display screen; the obtained compensation coefficient is sent to the control chip, so that the control chip performs brightness compensation on the corresponding LED lamp bead based on the compensation coefficient, and the control chip is located in the LED display screen.

Optionally, the brightness compensation device can be connected to the camera and the LED display screen by wire or wirelessly. Also optionally, the camera can be used as a built-in module of the brightness compensation device, in which case the brightness compensation system includes the LED display screen and the brightness compensation device including the camera. Also optionally, the LED display screen can be used as a built-in module of the brightness compensation device, in which case the brightness compensation system includes the camera and the brightness compensation device including the LED display screen.

In addition, an embodiment of the present application also provides a storage medium containing computer executable instructions, which, when executed by a computer processor, are used to perform relevant operations in the brightness compensation method provided in any embodiment of the present application, and have corresponding functions and beneficial effects.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products.

Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The application is described with reference to the flowchart and/or block diagram of the method, device (system) and computer program product according to the embodiment of the application. It should be understood that each flow and/or box in the flow chart and/or block diagram and the combination of the flow chart and/or box in the flow chart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of a computer or other programmable data processing device produce a device for realizing the function specified in one flow chart or multiple flows and/or one box or multiple boxes of a block diagram. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes of the flowchart and/or one or more blocks of the block diagram. These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operating steps are performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes of the flowchart and/or one or more blocks of the block diagram.

In a typical configuration, a computing device includes one or more processors (CPU), input/output interfaces, network interfaces, and memory. The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and/or non-volatile memory in the form of read-only memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined in this article, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

A brightness compensation method, comprising:

Acquire a plurality of collected images, wherein the plurality of collected images include images collected from a display screen of an LED display screen with a set grayscale, and the compensation times of the plurality of collected images are all different;

Obtaining a first brightness value of each LED lamp bead in the LED display screen in each collected image, and determining a target brightness value of each LED lamp bead;

Determine a compensation coefficient for each LED lamp bead according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each collected image, and the compensation time of each collected image, wherein the compensation coefficient is proportional to the increase in brightness required when the corresponding LED lamp bead reaches the target brightness value;

When the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, updating the compensation coefficient of the first LED lamp bead to the coefficient threshold, wherein the first LED lamp bead is any lamp bead in the LED display screen;

The obtained compensation coefficient is sent to the control chip, so that the control chip performs brightness compensation on the corresponding LED lamp beads based on the compensation coefficient, and the control chip is located in the LED display screen.
The brightness compensation method according to claim 1, wherein the compensation time of the multiple acquired images increases in the order in which the images are acquired.
According to the brightness compensation method of claim 2, wherein, for two acquired images in adjacent acquisition order among the multiple acquired images, the difference between the compensation time of the latter acquired image and the compensation time of the previous acquired image is the set step size.
According to the brightness compensation method of claim 3, wherein the determining the compensation coefficient of each LED lamp bead according to the target brightness value of each LED lamp bead, the first brightness value of the corresponding LED lamp bead in each collected image, and the compensation time corresponding to each collected image comprises:

Determine a second brightness value of each LED lamp bead according to the first brightness value of each LED lamp bead in each collected image, wherein the second brightness value is a first brightness value of each of the first brightness values of the corresponding LED lamp bead that is less than and only less than the target brightness value;

Determine a brightness difference between the target brightness value and the second brightness value, and determine a brightness increase value corresponding to the set step size;

The compensation coefficient of the LED lamp bead is determined according to the brightness difference, the brightness increase value, the set step size, and the compensation time of the collected image corresponding to the second brightness value.
The brightness compensation method according to claim 4, further comprising:

If the second brightness value of the second LED lamp bead does not exist, the compensation coefficient of the second LED lamp bead is determined to be zero, and the second LED lamp bead is any lamp bead in the LED display screen.
The brightness compensation method according to claim 4, wherein when the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, updating the compensation coefficient of the first LED lamp bead to the coefficient threshold comprises:

When the second brightness value of the first LED lamp bead is the maximum first brightness value of the first LED lamp bead in each of the collected images, determining whether the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold;

When the compensation coefficient is greater than the coefficient threshold, the compensation coefficient of the first LED lamp bead is updated to the coefficient threshold.
The brightness compensation method according to claim 1, wherein determining the target brightness value of each LED lamp bead comprises:

Select a target image from among the acquired images;

The first brightness value of each of the LED lamp beads in the target image is obtained, and the average value of each of the first brightness values is used as the target brightness value of each of the LED lamp beads.
According to the brightness compensation method of claim 1, the display screen of the LED display screen is a pure color image, the pure color image includes a red image, a green image and a blue image, and the LED lamp beads have a corresponding compensation coefficient under each pure color.
The brightness compensation method according to claim 1, wherein the grayscale value of the set grayscale of each of the LED lamp beads in the LED display screen is less than the grayscale threshold.
A brightness compensation device, comprising:

An image acquisition unit, used to acquire a plurality of acquired images, wherein the plurality of acquired images include images acquired from a display screen of an LED display screen with a set grayscale, and the compensation times of the plurality of acquired images are all different;

A brightness determination unit, used to obtain a first brightness value of each LED lamp bead in the LED display screen in each collected image, and to determine a target brightness value of each LED lamp bead;

A coefficient determination unit, configured to determine a compensation coefficient of each LED lamp bead according to a target brightness value of each LED lamp bead, a first brightness value of the corresponding LED lamp bead in each collected image, and a compensation time of each collected image, wherein the compensation coefficient is proportional to an increase in brightness required when the corresponding LED lamp bead reaches the target brightness value;

A coefficient modification unit, configured to update the compensation coefficient of a first LED lamp bead to the coefficient threshold when the compensation coefficient of the first LED lamp bead is greater than the coefficient threshold, wherein the first LED lamp bead is any lamp bead in the LED display screen;

The coefficient sending unit is used to send the obtained compensation coefficient to the control chip so that the control chip can perform brightness compensation on the corresponding LED lamp beads based on the compensation coefficient. The control chip is located in the LED display screen.
A brightness compensation device, comprising:

one or more processors;

A memory for storing one or more programs;

When the one or more programs are executed by the one or more processors, the one or more processors implement the brightness compensation method as described in any one of claims 1-9.
A computer-readable storage medium stores a computer program, wherein when the program is executed by a processor, the brightness compensation method as described in any one of claims 1 to 9 is implemented.