Backlight control method and device, display device and computer readable storage medium

Abstract

The application discloses a backlight control method and device, a display device and a computer readable storage medium. The backlight control method comprises the following steps: acquiring a current image frame to be displayed and a previous image frame displayed in a previous time period; calculating a gray difference value of each partition of the current image frame and the previous image frame according to a partition gray value of each partition in the current image frame and a partition gray value of each partition in the previous image frame; and determining target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition, so as to realize the backlight brightness control when the current image frame is displayed. The application can achieve the contrast effect of the screen image while reducing the probability of the flicker phenomenon of the picture as much as possible.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a backlight control method and device, display equipment and computer readable storage medium. BACKGROUND

[0002] With the increasingly wide use of liquid crystal display, the requirement for liquid crystal display effect is also increasingly high. At present, liquid crystal display is mainly realized by backlight method. The existing backlight technology mainly includes global backlight adjustment technology, local backlight adjustment technology, color local backlight adjustment technology, etc. The most easily realized and the best display effect is the local backlight adjustment technology. The local backlight adjustment technology refers to a technology of dividing an LCD (Liquid Crystal Display) into a plurality of partitions, and automatically controlling the brightness of the backlight source of each region according to the gray scale of the image of each partition after analyzing and calculating the gray scale of each partition. The technology uses a large number of LEDs (Light-Emitting Diodes) to form a backlight screen. The LEDs in the backlight screen can be adjusted according to the brightness of the image, so that the brightness of the highlight part of the display image can reach the maximum, and the brightness of the dark part can be reduced or even turned off, thereby achieving the best contrast and better display quality.

[0003] At present, the brightness of the image frame is established by the RGB input signal. Although the local backlight adjustment technology can enhance the contrast of the image frame and obtain good quality effect, if the image brightness of adjacent image frames constituting a video frequently changes, the backlight flicker phenomenon will occur, thereby affecting the visual experience of video watching. SUMMARY

[0004] The main purpose of the present application is to provide a backlight control method, device, display equipment and computer readable storage medium, which aims to solve the technical problem that the existing local backlight adjustment technology easily causes the display picture to flicker when the display picture is switched.

[0005] To achieve the above purpose, the present application provides a backlight control method, which comprises the following steps:

[0006] obtaining a current image frame to be displayed and a previous image frame displayed in a previous time period;

[0007] According to the partition gray scale value of each partition in the current image frame and the partition gray scale value of each partition in the previous image frame, the gray scale difference value of each partition of the current image frame and the previous image frame is calculated;

[0008] According to the size of the gray difference value of each partition, target backlight brightness data of each partition in the current image frame is determined to realize backlight brightness control when the current image frame is displayed.

[0009] Optionally, the step of determining the target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition further comprises:

[0010] Partitions with the gray difference value greater than or equal to a first preset gray threshold are taken as backlight update partitions;

[0011] Update backlight brightness data corresponding to the current image frame in the backlight update partition is obtained;

[0012] The update backlight brightness data is taken as the target backlight brightness data of the current image frame in the backlight update partition.

[0013] Optionally, the step of determining the target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition comprises:

[0014] Partitions with the gray difference value less than the first preset gray threshold and not equal to zero are taken as backlight maintaining partitions;

[0015] Historical backlight brightness data corresponding to the previous image frame in the backlight maintaining partition is obtained;

[0016] The historical backlight brightness data is taken as the target backlight brightness data of the current image frame in the backlight maintaining partition.

[0017] Optionally, the step of obtaining the historical backlight brightness data corresponding to the previous image frame in the backlight maintaining partition comprises:

[0018] The number of the backlight maintaining partitions is counted, and the total number of all the partitions is obtained;

[0019] The ratio of the number of the backlight maintaining partitions to the total number is calculated, and it is determined whether the ratio is less than or equal to a preset proportion threshold;

[0020] If the ratio is less than or equal to the preset proportion threshold, the step of obtaining the historical backlight brightness data corresponding to the previous image frame in the backlight maintaining partition is performed.

[0021] Optionally, if the ratio is less than or equal to the preset proportion threshold, the step of obtaining the historical backlight brightness data corresponding to the previous image frame in the backlight maintaining partition comprises:

[0022] if the ratio is less than or equal to a preset proportion threshold, calculating a sum value of gray difference values of all the backlight maintaining partitions to obtain a total gray difference value;

[0023] judging whether the total gray difference value is less than or equal to a second preset gray threshold, wherein the second preset gray threshold is greater than the first preset gray threshold;

[0024] if the total gray difference value is less than or equal to the second preset gray threshold, performing the step of obtaining the historical backlight luminance data of the previous image frame corresponding to the backlight maintaining partition.

[0025] Optionally, the step of judging whether the ratio is less than or equal to a preset proportion threshold further comprises:

[0026] if the ratio is greater than the preset proportion threshold, converting the backlight maintaining partition into a backlight updating partition;

[0027] obtaining updating backlight luminance data corresponding to the backlight updating partition of the current image frame;

[0028] taking the updating backlight luminance data as target backlight luminance data of the current image frame in the backlight updating partition.

[0029] Optionally, the step of calculating the gray difference value of each partition of the current image frame and the previous image frame according to the partition gray value of each partition in the current image frame and the partition gray value of each partition in the previous image frame further comprises:

[0030] obtaining a first pixel gray value of each pixel in the current image frame and a second pixel gray value of each pixel in the previous image frame;

[0031] calculating a first average pixel gray value of all pixels in each partition of the current image frame based on the first pixel gray value, and calculating a second average pixel gray value of all pixels in each partition of the previous image frame based on the second pixel gray value;

[0032] taking the first average pixel gray value of each partition in the current image frame as the partition gray value of each partition in the current image frame, and taking the second average pixel gray value of each partition in the previous image frame as the partition gray value of each partition in the previous image frame.

[0033] In addition, to achieve the above object, the present application further provides a backlight control device, which comprises:

[0034] an obtaining module, configured to obtain a current image frame to be displayed and a previous image frame displayed in a previous time period;

[0035] a calculating module, configured to calculate a gray difference value of each partition between the current image frame and the previous image frame according to a partition gray value of each partition in the current image frame and a partition gray value of each partition in the previous image frame;

[0036] a determining module, configured to determine target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition, so as to realize backlight brightness control when the current image frame is displayed.

[0037] In addition, to achieve the above object, the present application also provides a display device, which comprises a memory, a processor and a backlight control program stored in the memory and executable on the processor, and the processor implements the steps of the backlight control method as above when executing the backlight control program.

[0038] In addition, to achieve the above object, the present application also provides a computer readable storage medium, which stores a backlight control program, and the processor implements the steps of the backlight control method as above when executing the backlight control program.

[0039] The present application can compare the partition gray scale values of the same backlight region of the adjacent two frames, so as to make whether to update the backlight, thereby avoiding the picture flicker problem caused by the need to update the backlight when the partition gray scale value difference of the adjacent two frames is small, and achieving the purpose of optimizing the LD display effect.

[0040] The present application can compare the partition gray scale values of the same backlight region of the adjacent two frames, so as to make whether to update the backlight, thereby avoiding the picture flicker problem caused by the need to update the backlight when the partition gray scale value difference of the adjacent two frames is small, and achieving the purpose of optimizing the LD display effect. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a structural schematic diagram of a display device of a hardware running environment related to the embodiment scheme of the present application;

[0042] Figure 2 is a flowchart of the first embodiment of the backlight control method of the present application;

[0043] Figure 3The detailed flowchart of step S30 in the second embodiment of the backlight control method of the present application is shown in the figure.

[0044] Figure 4 The flowchart of the backlight control method in a specific embodiment of the present application is shown in the figure.

[0045] Figure 5 The device module diagram of the backlight control device in an embodiment of the present application is shown in the figure.

[0046] The purposes, functional features and advantages of the present application will be further explained in combination with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0047] It should be understood that the specific embodiments described herein are merely used to explain the present application and not to limit the present application.

[0048] It should be understood that the specific embodiments described herein are merely used to explain the present application and not to limit the present application.

[0049] Reference Figure 1 , Figure 1 The structural diagram of the display device of the hardware running environment involved in the embodiment scheme of the present application is shown in the figure.

[0050] As Figure 1 shown, the display device can include a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 can include a display screen (Display) and an input unit such as a keyboard (Keyboard). The optional user interface 1003 can also include a standard wired interface, a wireless interface. The network interface 1004 can optionally include a standard wired interface, a wireless interface (such as a wireless fidelity (WIreless-FIdelity, WI-FI) interface). The memory 1005 can be a high-speed random access memory (RAM) memory, or a stable non-volatile memory (NVM), such as a magnetic disk memory. The memory 1005 can also be an independent storage device from the aforementioned processor 1001.

[0051] Those skilled in the art can understand Figure 1 that the structure shown in the figure does not constitute a limitation on the display device, and can include more or fewer components than the figure, or combine certain components, or different component arrangements.

[0052] AsFigure 1 As shown, the memory 1005 as a storage medium can include an operating system, a data storage module, a network communication module, a user interface module, and a display device backlight control program.

[0053] In Figure 1 As shown in the display device, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the display device can be arranged in the display device, the display device calls the backlight control program stored in the memory 1005 through the processor 1001, and executes each step of the display device backlight control method provided by the embodiment of the application.

[0054] The previous display type LCD (Liquid Crystal Display) electronic product is global light control, that is, the backlight part is fully bright after the TV is turned on, and the current picture content is not fully referred to. The backlight cannot change with the change of the picture content, so the picture contrast is poor, the dark scene is not dark, and there is a large power loss. Local dimming (local backlight adjustment) can control the backlight partition, which is an image processing technology that can adjust the backlight brightness or contrast in real time according to the current frame picture. It can reduce the power consumption of the whole machine, improve the contrast, and make the picture contrast effect more obvious.

[0055] The local backlight adjustment method is essentially to divide the backlight module or backlight source of the display device into a plurality of backlight partitions (the "backlight partition" corresponds to the "partition" described in the embodiment) that can be independently driven, and then independently control the light emitting brightness of the backlight light source in each backlight partition. Each backlight partition can include one or more light emitting diodes (LED) as a light source. According to the gray value required by the image to be displayed of the display picture, the driving current of the LED corresponding to the backlight partition is adjusted, so as to realize the independent adjustment of the brightness of each backlight partition in the backlight module. For example, the liquid crystal display device LCD includes a display panel and a backlight module, the display panel itself does not emit light, but the backlight module provides backlight as a light source. The backlight module can be controlled by combining the local backlight adjustment method, so as to improve the display quality of the display panel. The local backlight adjustment method can not only reduce the power consumption of the display panel, but also realize dynamic dimming of the backlight module, improve the contrast of the display image, and improve the display quality of the display panel.

[0056] The brightness of the image frame is established by RGB (red green blue) input signals by superimposing certain parts of the RGB signals together. The video is composed of a plurality of continuously played image frames. Although the local backlight adjustment technology can enhance the contrast of the image frame and obtain good picture quality effect, the brightness data of each backlight partition is refreshed in real time according to the image signal, and the image light and dark between adjacent image frames constituting the video changes, which causes the backlight flicker phenomenon, thereby affecting the visual experience of video watching. At the same time, the display terminal also causes the backlight flicker problem in the signal stream processing process due to the opening of boost (dynamic range expansion) amplification, such as the movement of small objects in the same scene or scene change. The data in the picture will jump, and the LD SPI SRAM Data (local dimming Serial Peripheral Interface Static Random-Access Memory Data), that is, the parameter transmitted by the SOC (System on Chip) to the backlight control unit, will change with the video data. After the boost is opened, the data corresponding to the current effective value sent by the SOC end also dynamically changes, and the frequent change of the current effective value will cause the picture flicker problem in multiple scenes. In addition, if other pq (Picture Quality) adjustment functions related to brightness processing are opened, such as picture sharpness enhancement, image noise reduction and the like, the probability of the picture flicker problem will be increased.

[0057] Based on this, with reference to Figure 2 The present application provides a backlight control method. In a first embodiment of the backlight control method, the backlight control method comprises the following steps:

[0058] In step S10, a current image frame to be displayed and a previous image frame displayed in a previous time period are obtained.

[0059] In step S20, the gray difference values of each partition of the current image frame and the previous image frame are calculated according to the partition gray values of each partition in the current image frame and the partition gray values of each partition in the previous image frame.

[0060] The display device of the embodiment can be a smart television, a smart phone or the like terminal device. Illustratively, according to the display device, the backlight module of the display backlight source thereof can be divided into a plurality of backlight partitions, and the backlight values of the backlight partitions are dynamically controlled to reduce the energy consumption of the display device. For example, when the display device is a 45-inch smart television, the backlight partitions thereof can be 100, and when the display device is a 65-inch smart television, the backlight partitions thereof can be 200. Of course, when the display device is a smart phone, the backlight partitions thereof can also be divided into different numbers of backlight partitions according to the screen size. The current image frame represents an image frame to be displayed at the current time, and the last image frame represents an image frame displayed at the last time period. The embodiment can send the backlight data of each backlight partition to the SOC end of the display device through a serial peripheral interface, and the SOC end sends the backlight data of each backlight partition to the backlight control unit after processing to control the backlight of the current picture. It is easy to understand that each backlight partition of the display interface corresponds to each partition of the image frame. In addition, the partition gray value of a certain partition represents the gray value of the image frame corresponding to the partition. That is, when displaying the image frame, the embodiment divides the image frame into many independent partitions, and adjusts the light and dark changes of each partition through the backlight control unit. The SOC end can deliver the brightness of each LED light bar to the backlight control unit through the RT_PM interactive element, and the backlight control unit adjusts the current size of the LED light bar according to the brightness value of each light bar to realize the brightness change of the light bar area, so that the display interface shows different image effects and improves the picture contrast.

[0061] According to the partition gray value of each partition in the current image frame and the partition gray value of each partition in the previous image frame, the gray difference value of each partition of the current image frame and the previous image frame is calculated. Specifically, the partition gray value of each partition in the current image frame is respectively subtracted from the partition gray value of each partition in the previous image frame, so as to obtain the gray difference value of each partition of the current image frame and the previous image frame. For example, the display interface of the display device includes backlight partition A, backlight partition B, backlight partition C and backlight partition D, wherein the backlight partition A is mapped to the partition a of the image frame. The backlight partition B is mapped to the partition b of the image frame. The backlight partition C is mapped to the partition c of the image frame. The backlight partition D is mapped to the partition d of the image frame. Then the gray value of the image covered by the partition a in the current image frame is subtracted from the gray value of the image covered by the partition a in the previous image frame to obtain the gray difference value of the partition a. The gray value of the image covered by the partition b in the current image frame is subtracted from the gray value of the image covered by the partition b in the previous image frame to obtain the gray difference value of the partition b. The gray value of the image covered by the partition c in the current image frame is subtracted from the gray value of the image covered by the partition c in the previous image frame to obtain the gray difference value of the partition c. The gray value of the image covered by the partition d in the current image frame is subtracted from the gray value of the image covered by the partition d in the previous image frame to obtain the gray difference value of the partition d.

[0062] As an example, before the step of calculating the gray difference value of each partition of the current image frame and the previous image frame according to the partition gray value of each partition in the current image frame and the partition gray value of each partition in the previous image frame, the step S20 includes:

[0063] Step A10, obtaining the first pixel gray value of each pixel in the current image frame and the second pixel gray value of each pixel in the previous image frame;

[0064] In the embodiment, each partition of the image frame includes a plurality of pixels, and each pixel has a corresponding pixel gray value. Those skilled in the art can understand that the pixel gray value can represent the brightness of a pixel. Specifically, the pixel gray value is between 0 and 255, the closer the pixel gray value is to 255, the higher the pixel brightness, and the closer the pixel gray value is to 0, the lower the pixel brightness. That is, the pixels around 255 are highlights, the pixels around 0 are dark tones, and the middle tones are around 128.

[0065] Step A20, based on the first pixel gray value, calculating the first average pixel gray value of all pixels in each partition of the current image frame, and based on the second pixel gray value, calculating the second average pixel gray value of all pixels in each partition of the previous image frame;

[0066] Step A30, the first average pixel gray value of each partition in the current image frame is taken as the partition gray value of each partition in the current image frame, and the second average pixel gray value of each partition in the previous image frame is taken as the partition gray value of each partition in the previous image frame.

[0067] Specifically, taking calculating the average pixel gray value of a partition as an example, the calculation method of the average pixel gray value is briefly described as follows:

[0068] The number of pixels in the partition and the pixel gray value of each pixel are obtained, the sum of the pixel gray values of all pixels in the partition is calculated, and the quotient between the sum of the pixel gray values of the partition and the number of pixels in the partition is calculated. The quotient is the average pixel gray value of the partition. For example, the number of pixels in the partition is 100, and the sum of the pixel gray values of the 100 pixels is 2550. Therefore, the average pixel gray value is 25.5. The average pixel gray value reflects the brightness of the partition, and the average pixel gray value of the partition is taken as the partition gray value of the partition.

[0069] After the step S20, the step S30 is performed, and the target backlight brightness data of each partition in the current image frame is determined according to the size of the gray difference value of each partition.

[0070] In the embodiment, the target backlight brightness data of each partition in the current image frame refers to the backlight brightness data required when the current image frame is displayed.

[0071] In the embodiment, the SOC end of the display device obtains the backlight data in the output image frame and sends it to the backlight control unit. The backlight control unit obtains the backlight control data of each backlight partition of the display interface according to the backlight data, and the backlight brightness control when the current image frame is displayed is completed by the backlight control unit. The backlight partitions of the display interface and the partitions of the image frame are one-to-one corresponding.

[0072] Those skilled in the art can know that the embodiment can calculate the gray value of each partition in the image frame according to the YUV (Luminance-Bandwidth-Chrominance) or RGB (red green blue) information of the image frame, and respectively calculate the difference between the partition gray value of each partition in the current image frame and the partition gray value of each partition in the previous image frame, so as to obtain the gray difference value of each partition of the current image frame and the previous image frame, and then calculate the target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition. For example, the display device realizes the acquisition of the RGB (red green blue) value or YUV value of the current image frame and the histogram statistics by the preset statistical function in the register of the local dimming function module, and the display device calculates the gray value data of the current image frame by the additional thread preset in the SOC, and determines the gray difference value of each partition in the current image frame according to the gray value data of the current image frame and the gray value data of the previous image frame calculated in the previous time period, and then determines the target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition.

[0073] As an example, refer to Figure 3 , the step of determining the target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition comprises:

[0074] Step S31, the partition with the gray difference value less than the first preset gray threshold and not equal to zero is taken as a backlight maintaining partition;

[0075] Step S32, the historical backlight brightness data corresponding to the backlight maintaining partition of the previous image frame is acquired;

[0076] Step S33, the historical backlight brightness data is taken as the target backlight brightness data of the backlight maintaining partition of the current image frame.

[0077] In the embodiment, the historical backlight brightness data corresponding to the backlight maintaining partition of the previous image frame refers to the backlight brightness data used in the backlight maintaining partition when the previous image frame is displayed.

[0078] It should be noted that the value of the first preset gray threshold is not specifically limited in this embodiment, so as to achieve the contrast effect of the screen image, and at the same time, the probability of screen image flicker is reduced. In an example, when the gray difference value of the a partition is less than the first preset gray threshold and not equal to zero, it means that even if the target backlight brightness data of the current image frame in the a partition continues to use the backlight brightness data used in the a partition of the previous image frame, the contrast effect of the screen image will not be affected. If the target backlight brightness data continues to use the backlight brightness data used in the a partition of the previous image frame, i.e., the backlight brightness data of the a partition is not updated, the brightness level of the current image frame in the a partition will be consistent with that of the previous image frame in the a partition, so that the contrast effect of the screen image can be achieved while the probability of screen image flicker is reduced, and the technical problem that the existing local backlight adjustment technology easily causes display flicker when the display image is switched is overcome. At the same time, since the new target backlight brightness data does not need to be calculated again through the local dimming function module, the running load of the display device is reduced.

[0079] In this embodiment, whether the gray difference value of each partition is less than the first preset gray threshold and not equal to zero is determined respectively, so as to judge the brightness difference value of each partition in the adjacent two image frames according to the gray difference value of each partition in the adjacent two image frames, and judge whether the historical backlight brightness data needs to be used according to the brightness difference value of each partition. When the gray difference value of the a partition is less than the first preset gray threshold and not equal to zero, it means that even if the target backlight brightness data of the current image frame in the a partition continues to use the historical backlight brightness data used in the a partition of the previous image frame, the contrast effect of the screen image will not be affected. By taking the partition with the gray difference value less than the first preset gray threshold and not equal to zero as the backlight maintaining partition, the historical backlight brightness data of the previous image frame in the backlight maintaining partition is obtained, and the historical backlight brightness data is taken as the target backlight brightness data of the current image frame in the backlight maintaining partition, the backlight brightness data of the a partition of the current image frame continues to use the backlight brightness data used in the a partition of the previous image frame without affecting the contrast effect of the screen image, so that the backlight brightness data of the a partition of the current image frame is not updated when the backlight brightness data of the a partition of the current image frame continues to use the backlight brightness data used in the a partition of the previous image frame without affecting the contrast effect of the screen image, the brightness level of the a partition of the current image frame is consistent with that of the a partition of the previous image frame, the probability of screen image flicker is reduced while the contrast effect of the screen image is achieved, the backlight flicker problem caused by LD is optimized, and the technical problem that the existing local backlight adjustment technology easily causes display flicker when the display image is switched is overcome.

[0080] The embodiment can compare the partition gray scale values of the same backlight region of the adjacent two frames, so as to determine whether to update the backlight, thereby avoiding the picture flicker problem caused by the need to update the backlight when the partition gray scale value difference of the adjacent two frames is small, and achieving the purpose of optimizing the LD display effect.

[0081] The embodiment can compare the partition gray scale values of the same backlight region of the adjacent two frames, so as to determine whether to update the backlight, thereby avoiding the picture flicker problem caused by the need to update the backlight when the partition gray scale value difference of the adjacent two frames is small, and achieving the purpose of optimizing the LD display effect.

[0082] In an implementable manner, the step of determining the target backlight brightness data of each partition in the current image frame according to the size of the gray scale difference value of each partition further comprises:

[0083] Step C10, taking the partition with the gray scale difference value greater than or equal to the first preset gray scale threshold value as a backlight update partition;

[0084] Step C20, obtaining the update backlight brightness data corresponding to the current image frame in the backlight update partition;

[0085] Step C30, taking the update backlight brightness data as the target backlight brightness data of the current image frame in the backlight update partition.

[0086] In the embodiment, when the gray difference value of a certain partition is large enough, and the backlight brightness data of the current image frame in the partition needs to be updated to improve the contrast effect of the image (the "update" is relative to the backlight brightness data used in the partition of the previous image frame), the backlight brightness data of the current image frame in the partition is updated, so as to reduce the frequency of backlight change under similar image scenes, reduce the flicker phenomenon, and achieve the contrast effect of the screen image and enhance the performance of the display device when displaying images.

[0087] In a possible implementation, the step of obtaining the historical backlight brightness data corresponding to the backlight keeping partition of the previous image frame comprises:

[0088] Step D10, counting the number of the backlight keeping partitions, and obtaining the total number of all the partitions;

[0089] Step D20, calculating the ratio of the number of the backlight keeping partitions to the total number, and determining whether the ratio is less than or equal to a preset proportion threshold;

[0090] Step D30, if the ratio is less than or equal to the preset proportion threshold, performing the step of obtaining the historical backlight brightness data corresponding to the backlight keeping partition of the previous image frame.

[0091] In the embodiment, it is necessary to note that if the ratio is greater than the preset proportion threshold, the backlight keeping partition is converted into a backlight update partition, the update backlight brightness data corresponding to the current image frame in the backlight update partition is obtained, and the update backlight brightness data is taken as the target backlight brightness data of the current image frame in the backlight update partition.

[0092] In the embodiment, the value of the preset proportion threshold is determined according to the contrast effect of the screen image and the probability of reducing the flicker phenomenon of the screen image, and the embodiment is not limited specifically, for example, the preset proportion threshold is 0.5.

[0093] When the ratio is less than or equal to the preset ratio threshold, it is determined that the contrast effect of the screen image will not be affected even if the target backlight brightness data of the current image frame in the backlight maintaining partition continues to use the backlight brightness data used by the previous image frame in the backlight maintaining partition. Therefore, in the embodiment, if the ratio is less than or equal to the preset ratio threshold, the historical backlight brightness data corresponding to the previous image frame in the backlight maintaining partition is obtained, so that the target backlight brightness data continues to use the backlight brightness data used by the previous image frame in the backlight maintaining partition, and the backlight brightness data does not need to be updated. At this time, the brightness of the current image frame in the backlight maintaining partition is consistent with the brightness of the previous image frame in the backlight maintaining partition, the probability of flicker of the screen image is reduced while the contrast effect of the screen image is achieved, and the technical problem that the existing local dimming technology easily causes flicker of the display image during display image switching is overcome. At the same time, the running load of the display device is reduced because the local dimming function module does not need to be used to calculate new target backlight brightness data.

[0094] When the ratio is greater than the preset ratio threshold, it is determined that the backlight brightness data of the current image frame in the backlight updating partition needs to be updated to improve the contrast effect of the screen image (the update is relative to the backlight brightness data used by the previous image frame in the backlight updating partition). Therefore, in the embodiment, if the ratio is greater than the preset ratio threshold, the backlight maintaining partition is converted into the backlight updating partition, the updating backlight brightness data corresponding to the current image frame in the backlight updating partition is obtained, and the updating backlight brightness data is used as the target backlight brightness data of the current image frame in the backlight updating partition, so that the backlight brightness data of the current image frame in the backlight updating partition is updated. The backlight change frequency in the similar image scene is reduced, the flicker phenomenon is reduced, the contrast effect of the screen image is achieved, and the display performance of the display device is enhanced while the backlight change frequency is reduced.

[0095] In an implementable manner, if the ratio is less than or equal to the preset ratio threshold, the step of obtaining the historical backlight brightness data corresponding to the previous image frame in the backlight maintaining partition includes:

[0096] In step E10, if the ratio is less than or equal to the preset ratio threshold, the sum of the gray difference values of all the backlight maintaining partitions is calculated to obtain a total gray difference value.

[0097] In step E20, it is determined whether the total gray difference value is less than or equal to a second preset gray threshold, where the second preset gray threshold is greater than the first preset gray threshold.

[0098] Step E30, if the total value of the gray scale difference is less than or equal to a second preset gray scale threshold, then performing the step of obtaining the historical backlight brightness data of the previous image frame corresponding to the backlight maintaining partition.

[0099] As an example, the step E20 further includes, after the step of judging whether the ratio is less than or equal to a preset proportion threshold, the step of:

[0100] Step F10, if the ratio is greater than the preset proportion threshold, then converting the backlight maintaining partition into a backlight updating partition.

[0101] Step F20, obtaining updating backlight brightness data of the current image frame corresponding to the backlight updating partition.

[0102] Step F30, taking the updating backlight brightness data as the target backlight brightness data of the current image frame in the backlight updating partition.

[0103] In the embodiment, the value of the second preset gray scale threshold is determined according to the contrast effect of the screen image and the probability of screen image flicker. The embodiment is not limited in detail. It should be noted that the second preset gray scale threshold is greater than the first preset gray scale threshold.

[0104] When the total value of the gray scale difference is less than or equal to the second preset gray scale threshold, it means that even if the target backlight brightness data of the current image frame in the backlight maintaining partition continues to use the historical backlight brightness data used by the previous image frame in the backlight maintaining partition, the contrast effect of the screen image will not be affected. Therefore, in the embodiment, if the total value of the gray scale difference is less than or equal to the second preset gray scale threshold, the step of obtaining the historical backlight brightness data of the previous image frame corresponding to the backlight maintaining partition is performed, so that the target backlight brightness data continues to use the historical backlight brightness data used by the previous image frame in the backlight maintaining partition, and the backlight brightness data does not need to be updated. At this time, the brightness and darkness of the current image frame in the backlight maintaining partition is consistent with that of the previous image frame in the backlight maintaining partition, so that the contrast effect of the screen image is achieved while the probability of screen image flicker is reduced as much as possible, thereby overcoming the technical problem that the existing local backlight adjustment technology easily causes display flicker when the display image is switched. At the same time, since the new target backlight brightness data calculation through the local dimming function module is not needed at this time, the running load of the display device is reduced.

[0105] When the total value of the gray scale difference is greater than the second preset gray scale threshold, it is determined that the brightness data of the backlight in the backlight update partition of the current image frame needs to be updated to improve the contrast effect of the screen image (the "update" is relative to the brightness data of the backlight used in the backlight update partition of the previous image frame). Therefore, in this embodiment, when the total value of the gray scale difference is greater than the second preset gray scale threshold, the backlight maintenance partition is converted into the backlight update partition, the update brightness data of the backlight in the backlight update partition corresponding to the current image frame is obtained, and the update brightness data is used as the target brightness data of the backlight in the backlight update partition of the current image frame, so that the brightness data of the backlight in the backlight update partition of the current image frame is updated, thereby reducing the frequency of backlight change in similar image scenarios and reducing the flicker phenomenon. At the same time of reducing the frequency of backlight change, the contrast effect of the screen image is also achieved, and the display performance of the display device is enhanced.

[0106] In order to help understand the technical concept of the present application, a specific embodiment is listed, please refer to Figure 4 :

[0107] 1. Confirm the backlight partition of the display device, and compare the diff value (i.e. the gray scale difference value) of the same block (i.e. the partition of the image frame) of the adjacent two image frames. Specifically, the SOC end of the display device calculates the average gray scale value (block_Yavg) of all pixels in each block according to the number of backlight partitions and the pixel gray scale value information in each block. Then compare the gray scale values of the same position blocks in adjacent two frames: diff_block=|block_Yavg_p1-block_Yavg_p2|

[0108] If diff_block

[0109] If diff_block>=x, the LD module normally transmits data, and the brightness of the backlight needs to be updated.

[0110] 2. Determine according to the number of blocks with changed position in adjacent two frames

[0111] A, |block_Yavg_p1-block_Yavg_p2|>0, i.e. diff_block≠0;

[0112] B, diff_block_sum=diff_block_sum+1 (wherein diff_block_sum is the number of backlight maintenance partitions described above);

[0113] C. When diff_block_sum> 50%block_sum, the LD module normally transmits data and updates the backlight (wherein block_sum is the total number of all partitions described above, and 50% is the value of the preset ratio threshold in the embodiment);

[0114] D. When diff_block_sum<= 50%block_sum, step 3 is entered.

[0115] 3. According to the total diff value of the adjacent two frames, the judgment is performed

[0116] If diff_all>y, the LD module normally transmits data and updates the backlight (wherein diff_all is the total gray difference value described above, and y is the second preset gray threshold described above);

[0117] If diff_all<=y, the LD module stops transmitting data and does not update the backlight.

[0118] It should be noted that the above embodiment describes many specific details, but only to help understand the technical concept of the application, and does not constitute a limitation on the application. More forms of simple changes based on the technical concept of the application are within the protection scope of the application.

[0119] In addition, with reference to Figure 5 , the embodiment of the application also provides a backlight control device, which comprises:

[0120] An acquisition module 10 is configured to acquire a current image frame to be displayed and a previous image frame displayed in a previous time period;

[0121] A calculation module 20 is configured to calculate a gray difference value of each partition of the current image frame and the previous image frame according to a partition gray value of each partition in the current image frame and a partition gray value of each partition in the previous image frame;

[0122] A determination module 30 is configured to determine target backlight brightness data of each partition in the current image frame according to the size of the gray difference value of each partition, so as to realize backlight brightness control when the current image frame is displayed.

[0123] Optionally, the determination module 30 is further configured to:

[0124] regard a partition with a gray difference value less than a first preset gray threshold and not equal to zero as a backlight maintaining partition;

[0125] acquire historical backlight brightness data corresponding to the backlight maintaining partition of the previous image frame;

[0126] the history backlight brightness data as target backlight brightness data of the current image frame in the backlight maintaining partition.

[0127] Optionally, the determining module 30 is further configured to:

[0128] take the partition with the gray difference value greater than or equal to the first preset gray threshold value as a backlight updating partition;

[0129] obtain updating backlight brightness data corresponding to the current image frame in the backlight updating partition;

[0130] take the updating backlight brightness data as target backlight brightness data of the current image frame in the backlight updating partition.

[0131] Optionally, the determining module 30 is further configured to:

[0132] count the number of the backlight maintaining partitions and obtain a total number of all the partitions;

[0133] calculate a ratio of the number of the backlight maintaining partitions to the total number and determine whether the ratio is less than or equal to a preset proportion threshold value;

[0134] if the ratio is less than or equal to the preset proportion threshold value, execute the step of obtaining the history backlight brightness data corresponding to the previous image frame in the backlight maintaining partition.

[0135] Optionally, the determining module 30 is further configured to:

[0136] if the ratio is less than or equal to the preset proportion threshold value, calculate a sum value of gray difference values of all the backlight maintaining partitions to obtain a total gray difference value;

[0137] determine whether the total gray difference value is less than or equal to a second preset gray threshold value, wherein the second preset gray threshold value is greater than the first preset gray threshold value;

[0138] if the total gray difference value is less than or equal to the second preset gray threshold value, execute the step of obtaining the history backlight brightness data corresponding to the previous image frame in the backlight maintaining partition.

[0139] Optionally, the determining module 30 is further configured to:

[0140] if the ratio is greater than the preset proportion threshold value, convert the backlight maintaining partition into a backlight updating partition;

[0141] obtain updating backlight brightness data corresponding to the current image frame in the backlight updating partition;

[0142] The updated backlight brightness data is taken as target backlight brightness data of the backlight update partition of the current image frame.

[0143] Optionally, the acquisition module 10 is further configured to:

[0144] acquire a first pixel gray value of each pixel in the current image frame and a second pixel gray value of each pixel in the previous image frame;

[0145] calculate a first average pixel gray value of all pixels in each partition in the current image frame based on the first pixel gray value, and calculate a second average pixel gray value of all pixels in each partition in the previous image frame based on the second pixel gray value;

[0146] take the first average pixel gray value of each partition in the current image frame as a partition gray value of each partition in the current image frame, and take the second average pixel gray value of each partition in the previous image frame as a partition gray value of each partition in the previous image frame.

[0147] The steps implemented by each functional module of the backlight control device can refer to the steps of each embodiment of the backlight control method, which will not be described here again.

[0148] In addition, the present application also provides a display device, which comprises a memory, a processor, and a backlight control program stored in the memory and executable on the processor, and the steps of the backlight control method are implemented when the backlight control program is executed by the processor.

[0149] The present application also provides a computer readable storage medium, which stores one or more programs executable by one or more processors to implement the steps of each embodiment of the backlight control method.

[0150] The computer readable storage medium of the present application has substantially the same implementation as the above-mentioned backlight control method, which will not be described here again.

[0151] It should be noted that, in this document, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such a process, method, article, or system. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article, or system including the element.

[0152] The above-mentioned embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0153] Through the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be realized by means of software and the necessary general hardware platform, of course, they can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as a ROM / RAM, a magnetic disk, or an optical disk) as described above, and includes a plurality of instructions for causing a terminal display device (which can be a mobile phone, a computer, a server, an air conditioner, or a network display device, etc.) to execute the methods described in the various embodiments of the present application.

[0154] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation made by using the content of the specification and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A backlight control method, characterized in that, The backlight control method includes the following steps: Get the current image frame to be displayed, and the previous image frame displayed in the previous time period; Based on the grayscale value of each partition in the current image frame and the grayscale value of each partition in the previous image frame, the grayscale difference value of each partition between the current image frame and the previous image frame is calculated. Based on the magnitude of the grayscale difference value of each partition, the target backlight brightness data of each partition in the current image frame is determined, so as to realize backlight brightness control when displaying the current image frame; The step of determining the target backlight brightness data of each partition in the current image frame based on the magnitude of the grayscale difference value of each partition includes: The partitions whose grayscale difference values ​​are less than the first preset grayscale threshold and are not equal to zero are designated as backlight retention partitions. Obtain the historical backlight brightness data corresponding to the backlight hold partition of the previous image frame, wherein the historical backlight brightness is the backlight brightness data used in the backlight hold partition when the previous image frame was displayed; The historical backlight brightness data is used as the target backlight brightness data of the current image frame in the backlight preservation partition; Before the step of obtaining the historical backlight brightness data of the previous image frame corresponding to the backlight preservation partition, the following steps are included: Count the number of backlight-maintaining zones and obtain the total number of all the zones; Calculate the ratio of the number of backlight-maintaining zones to the total number, and determine whether the ratio is less than or equal to a preset ratio threshold; If the ratio is less than or equal to a preset ratio threshold, the sum of the grayscale difference values ​​of all the backlight holding zones is calculated to obtain the total grayscale difference value. Determine whether the total grayscale difference value is less than or equal to a second preset grayscale threshold, wherein the second preset grayscale threshold is greater than the first preset grayscale threshold; If the total grayscale difference is less than or equal to the second preset grayscale threshold, then the step of obtaining the historical backlight brightness data of the previous image frame corresponding to the backlight preservation partition is executed. If the ratio is greater than a preset ratio threshold or the total grayscale difference is greater than the second preset grayscale threshold, then the backlight hold partition is converted into a backlight update partition. Obtain the updated backlight brightness data of the current image frame corresponding to the backlight update partition; The updated backlight brightness data is used as the target backlight brightness data of the current image frame in the backlight update partition.

2. The backlight control method as described in claim 1, characterized in that, The step of determining the target backlight brightness data of each partition in the current image frame based on the magnitude of the grayscale difference value of each partition further includes: The partitions whose grayscale difference values ​​are greater than or equal to the first preset grayscale threshold are designated as backlight update partitions. Obtain the updated backlight brightness data of the current image frame corresponding to the backlight update partition; The updated backlight brightness data is used as the target backlight brightness data of the current image frame in the backlight update partition.

3. The backlight control method as described in claim 1, characterized in that, Before the step of calculating the grayscale difference between each partition of the current image frame and the previous image frame based on the partition grayscale value of each partition in the current image frame and the partition grayscale value of each partition in the previous image frame, the following steps are included: Obtain the first pixel grayscale value of each pixel in the current image frame, and the second pixel grayscale value of each pixel in the previous image frame; Based on the first pixel gray value, the first average pixel gray value of all pixels in each partition of the current image frame is calculated, and based on the second pixel gray value, the second average pixel gray value of all pixels in each partition of the previous image frame is calculated. The first average pixel gray value of each partition in the current image frame is used as the partition gray value of each partition in the current image frame, and the second average pixel gray value of each partition in the previous image frame is used as the partition gray value of each partition in the previous image frame.

4. A backlight control device, characterized in that, The backlight control device includes: The acquisition module is used to acquire the current image frame to be displayed, as well as the previous image frame displayed in the previous time period; The calculation module is used to calculate the grayscale difference between each partition of the current image frame and the previous image frame based on the partition grayscale value of each partition in the current image frame and the partition grayscale value of each partition in the previous image frame. The determining module is used to determine the target backlight brightness data of each partition in the current image frame based on the magnitude of the grayscale difference value of each partition, so as to realize backlight brightness control when displaying the current image frame; to designate partitions whose grayscale difference value is less than a first preset grayscale threshold and is not equal to zero as backlight preservation partitions; to obtain the historical backlight brightness data of the previous image frame corresponding to the backlight preservation partition, wherein the historical backlight brightness is the backlight brightness data used in the backlight preservation partition when the previous image frame was displayed; and to use the historical backlight brightness data as the target backlight brightness data of the current image frame in the backlight preservation partition. The determining module is further configured to: count the number of backlight-preserving partitions and obtain the total number of all partitions; calculate the ratio of the number of backlight-preserving partitions to the total number, and determine whether the ratio is less than or equal to a preset ratio threshold; if the ratio is less than or equal to the preset ratio threshold, calculate the sum of the grayscale difference values ​​of all backlight-preserving partitions to obtain the total grayscale difference value; determine whether the total grayscale difference value is less than or equal to a second preset grayscale threshold, wherein the second preset grayscale threshold is greater than the first preset grayscale threshold; if the total grayscale difference value is less than or equal to the second preset grayscale threshold, execute the step of obtaining the historical backlight brightness data corresponding to the previous image frame in the backlight-preserving partition; if the ratio is greater than the preset ratio threshold or the total grayscale difference value is greater than the second preset grayscale threshold, convert the backlight-preserving partition into a backlight-update partition; obtain the updated backlight brightness data corresponding to the current image frame in the backlight-update partition; and use the updated backlight brightness data as the target backlight brightness data of the current image frame in the backlight-update partition.

5. A display device, characterized in that, The display device includes: a memory, a processor, and a backlight control program stored in the memory and executable on the processor, wherein the backlight control program, when executed by the processor, implements the steps of the backlight control method as described in any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a backlight control program, which, when executed by a processor, implements the steps of the backlight control method as described in any one of claims 1 to 3.

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