Display apparatus, image processing method, storage medium, and program product

Abstract

The embodiment of the invention belongs to the display technology, and provides a display device, an image processing method, a storage medium and a program product, the display device comprises a display screen, a backlight unit and a processor connected with the display screen and the backlight unit, and the processor is configured to divide a to-be-displayed image into N partitions corresponding to a backlight area, performing local dimming processing on the image of the N partitions to obtain a first target image and backlight values of the N backlight areas; determining whether the ratio of the number of pixels of which the gray values are smaller than a preset gray value in the first target image to the number of all pixels of the first target image is smaller than a preset threshold value or not; and if yes, performing contrast stretching processing on pixels in the target gray scale range in the first target image to obtain a second target image, and displaying the second target image. The display effect can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of display technology. More specifically, it relates to a display device, an image processing method, a storage medium, and a program product. Background Technology

[0002] Local Dimming (LD) is a backlighting technology that enhances image contrast and quality by dividing the backlight into multiple independently controllable zones. Each zone can adjust its backlight brightness independently according to the needs of the displayed content.

[0003] With the development of display technology, in order to provide users with a better picture quality experience, display devices (such as LCD TVs) can use LD technology to adjust the backlight and compensate the image to be displayed, thereby improving the display effect.

[0004] However, in some scenarios, the display effect of images processed by LD is not good. Summary of the Invention

[0005] This application provides a display device, an image processing method, a storage medium, and a program product, which can improve the display effect of images processed by LD.

[0006] In a first aspect, embodiments of this application provide a display device, the display device comprising:

[0007] The display screen is configured to display images;

[0008] A backlight unit is configured to provide a backlight source for the display screen, and the backlight unit is divided into N backlight areas, where N is an integer greater than 1;

[0009] And a processor connected to the display screen and the backlight unit respectively, the processor being configured to:

[0010] The image to be displayed is divided into N partitions corresponding to the backlight area, and local dimming processing is performed on the images of the N partitions to obtain the first target image, and the backlight values ​​of the N backlight areas.

[0011] Determine whether the proportion of the number of pixels in the first target image whose grayscale value is less than a preset grayscale value to the total number of pixels in the first target image is greater than a preset threshold;

[0012] If not, display the first target image;

[0013] If so, perform contrast stretching on the pixels in the first target image that are within the target grayscale range to obtain a second target image, and display the second target image; the target grayscale range does not include the grayscale range corresponding to the background;

[0014] Specifically, when displaying the first target image or the second target image, the corresponding backlight unit is controlled to emit light according to the backlight value of the N backlight areas.

[0015] In some embodiments, the processor is configured to:

[0016] Perform grayscale histogram statistics on the first target image, and obtain the grayscale distribution characteristics of the first target image based on the statistical results of the grayscale histogram.

[0017] Based on the grayscale distribution characteristics, the grayscale range corresponding to the background in the first target image is removed to obtain the initial grayscale range;

[0018] Based on the grayscale distribution characteristics, a typical image corresponding to the first target image is determined;

[0019] Based on the preset grayscale range of the typical image, the initial grayscale range is corrected to obtain the target grayscale range.

[0020] In some embodiments, the processor is configured to:

[0021] A preset stretching algorithm is used to process the typical image and the target grayscale range to obtain the stretching coefficient corresponding to the first target image. The stretching coefficient is used to adjust the grayscale value of the pixel. The stretching coefficient is a linear stretching coefficient or a non-linear stretching coefficient.

[0022] The grayscale values ​​of pixels in the first target image that fall within the target grayscale range are adjusted using the stretching coefficient to obtain the second target image.

[0023] In some embodiments, the processor is configured to:

[0024] The contrast stretching model is invoked to perform contrast stretching processing on the first target image to obtain the second target image; the contrast stretching model is obtained by training an initial stretching model using a training dataset, which includes a subset of sample images and a subset of target images; the sample images in the subset of sample images correspond one-to-one with the target images in the subset of target images, and the sample images carry the grayscale range to be stretched and the stretching coefficient; the stretching coefficient is determined based on the target image corresponding to the sample image.

[0025] In some embodiments, the processor is configured to:

[0026] When displaying the second target image, a first prompt message is output; the first prompt message is used to prompt the user whether they are satisfied with the current display effect.

[0027] If the received feedback indicates that the user is not satisfied with the current display effect, the second target image is uploaded to a preset server; the second target image is used to update the contrast stretching model.

[0028] or,

[0029] When displaying the second target image, if an adjustment instruction is received within a preset time period, the second target image is uploaded to a preset server. The adjustment instruction is used to adjust the brightness and / or contrast of the display screen.

[0030] In some embodiments, the processor is configured to:

[0031] Receive update instruction; the update instruction is used to instruct the contrast stretching model to be updated;

[0032] Read the data to be updated, which includes the update parameters of the contrast stretching model, or the new contrast stretching model;

[0033] The contrast stretching model can be updated using the updated parameters, or the new contrast stretching model can be used to replace the contrast stretching model.

[0034] In some embodiments, the processor is configured to:

[0035] Obtain image parameters of the second target image, including brightness and / or contrast;

[0036] If the image parameters are not within the preset parameter range, the image parameters are adjusted using a preset adjustment coefficient, and the second target image after the image parameters are adjusted is displayed.

[0037] or,

[0038] The second target image is post-processed, and the post-processed second target image is displayed; the post-processing includes one or more of noise removal, sharpening, and color correction.

[0039] Secondly, embodiments of this application provide an image processing method applied to a display device, the display device comprising: a display screen configured to display an image; and a backlight unit configured to provide a backlight source for the display screen, the backlight unit being divided into N backlight regions, where N is an integer greater than 1; the method comprising:

[0040] The image to be displayed is divided into N partitions corresponding to the backlight area, and local dimming processing is performed on the images of the N partitions to obtain the first target image, and the backlight values ​​of the N backlight areas.

[0041] Determine whether the proportion of the number of pixels in the first target image whose grayscale value is less than a preset grayscale value to the total number of pixels in the first target image is greater than a preset threshold;

[0042] If not, display the first target image;

[0043] If so, perform contrast stretching on the pixels in the first target image that are within the target grayscale range to obtain a second target image, and display the second target image; the target grayscale range does not include the grayscale range corresponding to the background;

[0044] Specifically, when displaying the first target image or the second target image, the corresponding backlight unit is controlled to emit light according to the backlight value of the N backlight areas.

[0045] Thirdly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method described in the second aspect.

[0046] Fourthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the second aspect.

[0047] Fifthly, embodiments of this application provide a chip, the chip including a processor, the processor being configured to invoke a computer program in memory to perform the method as described in the second aspect.

[0048] The display device, image processing method, storage medium, and program product provided in this application embodiment include: a display screen configured to display an image; a backlight unit configured to provide a backlight source for the display screen, the backlight unit being divided into N backlight regions, where N is an integer greater than 1; and a processor connected to the display screen and the backlight unit respectively, the processor being configured to: divide the image to be displayed into N partitions corresponding to the backlight regions, perform local dimming processing on the images of the N partitions to obtain a first target image, and the backlight values ​​of the N backlight regions; and adjust the backlight values ​​of the first target image... The target image is subjected to grayscale histogram statistics to determine whether the proportion of pixels with grayscale values ​​less than a preset grayscale value in the first target image is greater than a preset threshold. If not, the first target image is displayed. If so, the pixels in the first target image within the target grayscale range are subjected to contrast stretching processing to obtain a second target image, which is then displayed. The target grayscale range does not include the grayscale range corresponding to the background. When displaying the first or second target image, the corresponding backlight units are controlled to emit light based on the backlight values ​​of the N backlight regions. By performing contrast stretching processing on a portion of the image after local dimming, the display effect of that portion of the image can be effectively improved. Attached Figure Description

[0049] To more clearly illustrate the implementation methods in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0050] Figure 1 This is a schematic diagram of a display scenario provided in an embodiment of this application;

[0051] Figure 2 This is a schematic diagram of the structure of a display device provided in an embodiment of this application;

[0052] Figure 3 This is a schematic diagram of the structure of another display device provided in an embodiment of this application;

[0053] Figure 4 This is a schematic diagram of a local dimming process provided in an embodiment of this application;

[0054] Figure 5 A schematic flowchart of an image processing method provided in an embodiment of this application;

[0055] Figure 6 A schematic flowchart illustrating another image processing method provided in an embodiment of this application;

[0056] Figure 7 This is a schematic diagram of an image after local dimming processing, provided as an embodiment of this application.

[0057] Figure 8 This is a schematic diagram of a stretched image provided in an embodiment of this application;

[0058] Figure 9 A schematic diagram of an interface provided for this application;

[0059] Figure 10 A schematic diagram of the image processing apparatus provided in this application.

[0060] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0061] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments.

[0062] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0063] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0064] To facilitate understanding, a brief introduction will first be given to the parts involved in the embodiments of this application:

[0065] Local dimming is a backlight technology used in televisions and monitors to enhance image contrast and quality. Its basic principle is to divide the backlight into multiple independently controlled areas or blocks, each of which (called a dimming zone) can independently adjust its brightness according to the needs of the displayed content. This technology can reduce brightness in areas where deep blacks are needed, while increasing brightness in areas where bright details are needed, thus achieving a better visual effect. For example, when displaying a night sky scene, the dimming zone for the night sky will reduce its brightness, while the dimming zone for the stars will maintain a higher brightness.

[0066] Figure 1 This is a schematic diagram illustrating an operation scenario of a display device provided in an embodiment of this application. Figure 1 As shown, the user can operate the display device 200 to display information through the smart device 300 or the control device 100.

[0067] In some embodiments, the control device 100 may be a remote control. Communication between the remote control and the display device includes infrared protocol communication, Bluetooth protocol communication, and other short-range communication methods, controlling the display device 200 wirelessly or via wired means. Users can control the display device 200 by inputting user commands through buttons on the remote control, voice input, control panel input, etc.

[0068] In some embodiments, a smart device 300 (such as a mobile terminal, tablet computer, computer, laptop computer, etc.) may also be used to control the display device 200. For example, an application running on the smart device may be used to control the display device 200.

[0069] In some embodiments, the display device may receive instructions not through the aforementioned smart device or control device, but through touch or gestures.

[0070] In some embodiments, the display device 200 can also be controlled in ways other than the control device 100 and the smart device 300. For example, it can be controlled by directly receiving the user's voice commands through a module configured inside the display device 200 for acquiring voice commands, or it can be controlled by receiving the user's voice commands through a voice control device set outside the display device 200.

[0071] In some embodiments, the display device 200 also communicates with the server 400. The display device 200 may communicate via a local area network (LAN), wireless local area network (WLAN), and other networks. The server 400 may provide various content and interactive features to the display device 200. The server 400 may be a cluster or multiple clusters, and may include one or more types of servers.

[0072] Figure 2 This is a schematic diagram illustrating a possible hardware configuration of a display device 200 provided in this application. (See diagram for example.) Figure 3 As shown, in some embodiments, the display device 200 may include at least one of the following: a tuner 210, a communicator 220, a detector 230, an external device interface 240, a controller 250, a display 260, an audio output interface 270, a power supply 280, a memory 290, and a user interface 2100.

[0073] In some embodiments, the controller includes a processor, a video processor, an audio processor, a graphics processor, RAM, ROM, and a first interface to an nth interface for input / output.

[0074] The display 260 includes a display screen assembly for presenting images, a driving assembly for driving image display, a component for receiving image signals from the controller output, and a user interface for displaying video content, image content, menu control interface, and user control UI.

[0075] The display 260 may be a liquid crystal display, an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a Miniled LED, a MicroLED, a Micro-OLED, a quantum dot light-emitting diode (QLED), and a projection display, etc., and may also be a projection device and a projection screen.

[0076] The communicator 220 is a component used to communicate with external devices or servers according to various communication protocol types. For example, the communicator may include at least one of the following: a WiFi module, a Bluetooth module, a wired Ethernet module, other network communication protocol chips or near-field communication protocol chips, and an infrared receiver. The display device 200 can establish the transmission and reception of control signals and data signals with the external control device 100 or the server 400 through the communicator 220.

[0077] User interface 2100 can be used to receive control signals from control device 100 (such as infrared remote control).

[0078] Detector 230 is used to collect signals from the external environment or to interact with the external environment. For example, detector 230 includes a light receiver, a sensor for collecting ambient light intensity; or, detector 230 includes an image acquisition device, such as a camera, which can be used to collect external environmental scenes, user attributes, or user interaction gestures; or, detector 230 includes a sound acquisition device, such as a microphone, for receiving external sounds.

[0079] The external device interface 240 may include, but is not limited to, one or more of the following: High Definition Multimedia Interface (HDMI), analog or high-definition component input interface (component), composite video input interface (CVBS), USB input interface (USB), RGB port, etc. It may also be a composite input / output interface formed by multiple interfaces mentioned above.

[0080] The tuner / demodulator 210 receives broadcast television signals via wired or wireless means, and demodulates audio and video signals, such as EPG data signals, from multiple wireless or wired broadcast television signals.

[0081] In some embodiments, the controller 250 and the tuner 210 may be located in different separate devices, that is, the tuner 210 may also be located in an external device of the main device where the controller 250 is located, such as an external set-top box.

[0082] The controller 250 controls the operation of the display device and responds to user operations through various software control programs stored in the memory 290. The controller 250 controls the overall operation of the display device 200. For example, in response to receiving a user command to select a UI object to display on the monitor 260, the controller 250 can execute operations related to the object selected by the user command.

[0083] In some embodiments, the controller includes at least one of a central processing unit (CPU), a video processor, an audio processor, a graphics processing unit (GPU), RAM (random access memory), ROM (read-only memory), a first to an nth interface for input / output, a communication bus, etc.

[0084] Users can input commands through a graphical user interface (GUI) displayed on the monitor 260, and the user input interface receives the user input commands through the GUI. Alternatively, users can input commands by entering specific sounds or gestures, and the user input interface receives the user input commands by recognizing the sounds or gestures through sensors.

[0085] A "user interface" is the medium through which an application or operating system interacts and exchanges information with the user. It converts information from its internal form to a form that the user can accept. A common form of user interface is the graphical user interface (GUI), which refers to a user interface related to computer operation displayed graphically. It can be an icon, window, control, or other interface element displayed on the screen of an electronic device. Controls can include visual interface elements such as icons, buttons, menus, tabs, text boxes, dialog boxes, status bars, navigation bars, and widgets.

[0086] The display device provided in this application can have various implementation forms, such as a smart TV, a laser projection device, a monitor, an electronic bulletin board, an electronic table, etc. Figure 1 and Figure 2 This is one specific embodiment of the display device of this application.

[0087] The following is combined Figure 3 The process of displaying images on the display device is described.

[0088] Taking this display device as an example, which is based on backlight display technology, Figure 3 A schematic diagram of another display device provided in this application. Figure 3 As shown, the display device 300 may include: an image quality processing module 301, an image display control module 302, a display screen 303, a backlight control module 304, and a backlight panel 303.

[0089] In some embodiments, the image quality processing module 301 can be used to acquire image data and backlight data of the image to be displayed. The image quality processing module 301 can output the image data to the image display control module 302, so that the image display control module 302 can illuminate the display screen 303 according to the image data. The image quality processing module 301 can also output the backlight data to the backlight control module 304, so that the backlight control module 304 can illuminate the backlight panel 303 according to the backlight data.

[0090] In some embodiments, the image display control module 302 may be a timing controller (TCON), and the backlight control module 304 may be a backlight controller (BCON). The image quality processing module 301 may house the chassis of the display device. This chassis may be a system-on-a-chip (SOC), for example. In some embodiments, the processor of the display device may be the image quality processing module 302, for example.

[0091] The following is combined Figure 4 The process of local dimming of the display device is described.

[0092] Figure 4 A schematic diagram of the local dimming process provided in this application is shown below. Figure 4 As shown, after an image frame is input to the processor, the processor can extract the pixel values ​​of the image, perform zonal statistics on the extracted pixel values ​​based on the preset backlight zones, extract the backlight value of each backlight zone, and perform peak gain processing on the backlight value of each backlight zone to obtain the actual backlight value of each zone. The actual backlight value is then output to the backlight control module so that the backlight control module can light up the backlight panel of the corresponding zone according to the backlight value of each zone during the display process.

[0093] Simultaneously, the processor can also perform backlight diffusion distribution simulation (Light Spread Function, LSF) processing on the backlight values ​​of each zone using a light diffusion model, calculate the gain compensation of the image pixels in each zone, perform gain processing on the pixel values ​​of each zone using gain compensation, and perform pixel overflow protection processing to obtain the actual pixel values ​​of each zone, thereby obtaining the image data after local dimming processing. The image data after local dimming processing is then output to the image display control module so that the image display control module can light up the display screen according to the image data.

[0094] During the above processing, due to the characteristic of local dimming reducing the backlight of the local area, in some scenarios, such as the stars in the night sky, the stars will appear relatively dark after local dimming, resulting in poor display effect and affecting the user experience.

[0095] In view of this, embodiments of this application provide a display device and an image processing method, which, by identifying an image after local dimming processing, performs contrast stretching processing (also known as grayscale stretching) on ​​the image when it is determined that the image is a low grayscale range image, thereby improving the contrast performance of the image and thus improving the display effect of the image.

[0096] The technical solutions of this application will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. In the description of this application, unless otherwise expressly specified and limited, the terms should be broadly understood within the art. The embodiments of this application will now be described with reference to the accompanying drawings.

[0097] The display device provided in this application embodiment includes a display screen, a backlight unit, and a processor. The backlight unit (backlight panel) is divided into N (an integer greater than 1) backlight areas, and each backlight area can be independently controlled by the processor to adjust its brightness independently according to the needs of the displayed content. That is, this display device supports local dimming. The image processing method provided in this application embodiment can be applied to the processor of the display device. The following describes the method in conjunction with... Figure 5 The image processing method provided in the embodiments of this application will be described with the processor as the execution subject.

[0098] Figure 5 A flowchart illustrating the image processing method provided in the embodiments of this application. Figure 1 ,like Figure 5 As shown, it includes the following steps:

[0099] S501. Divide the image to be displayed into N partitions corresponding to the backlight area, perform local dimming processing on the images of the N partitions, and obtain the first target image and the backlight values ​​of the N backlight areas.

[0100] In some embodiments, the processor can divide the image into N image partitions corresponding one-to-one with the N backlight regions defined by the backlight unit, and each backlight region can provide backlight support for the image of the corresponding partition.

[0101] The processor performs local dimming processing on the images of the N partitions to obtain the first target image, and the backlight values ​​of the N backlight regions can be referenced. Figure 4 The implementation method shown will not be elaborated here.

[0102] S502. Determine whether the proportion of the number of pixels in the first target image whose grayscale value is less than a preset grayscale value to the total number of pixels in the first target image is less than a preset threshold. If not, proceed to step S503; if yes, proceed to step S504.

[0103] In some embodiments, when the processor acquires the first target image, it can perform grayscale histogram statistics on the first target image to obtain statistical results.

[0104] For example, the processor can perform grayscale histogram statistics on the first target image in the following manner:

[0105] In one possible implementation, the processor can convert the first target image into a grayscale image, extract the grayscale values ​​of each pixel in the grayscale image, and perform histogram statistics to obtain the statistical results.

[0106] In one possible implementation, when performing local dimming processing on the image to be displayed, the grayscale values ​​of each partition are extracted to obtain the backlight value of each partition. The processor can use the grayscale values ​​of each partition obtained during the local dimming process to perform histogram statistics on the grayscale values ​​of each partition to obtain the statistical results, thereby improving the statistical efficiency of the grayscale histogram.

[0107] In some embodiments, the grayscale histogram has a grayscale range of 0-255, representing different grayscale levels. When the grayscale value is 0, the pixel is pure black; when the grayscale value is 255, the pixel is pure white.

[0108] A pixel's grayscale value being less than a preset grayscale value can also be described as the pixel's grayscale value being in a low grayscale range. Low grayscale can refer to grayscale areas close to black (0) in a grayscale histogram. For example, the low grayscale range can be 0-50, 0-60, etc. This application embodiment does not limit the range of low grayscale. Correspondingly, the preset grayscale value is the upper limit of the low grayscale range, for example, 50, 60, etc. This application embodiment does not limit this value.

[0109] In some embodiments, when the processor obtains the statistical results of the grayscale histogram of the first target image, it can determine the proportion of the number of pixels in the low grayscale range to the total number of pixels based on the statistical results (i.e., the proportion of the number of pixels with grayscale values ​​less than a preset grayscale value to the total number of pixels in the first target image). If the proportion is greater than a preset threshold, it can be determined that the first target image is an image with a concentrated grayscale range, or an image with low overall contrast, or an image with strong contrast between light and dark distribution. The contrast performance of the image is poor and needs to be stretched.

[0110] If the percentage is less than or equal to the preset threshold, it can be determined that the image has good contrast and no stretching is required.

[0111] The preset threshold can be determined based on prior knowledge, such as 90%, 95%, etc., and this application embodiment does not limit it.

[0112] S503, Display the first target image.

[0113] When the processor determines that the contrast of the first target image is good, the processor can send the first target image to the image display control module, so that the image display control module can light up the display screen according to the first target image. At the same time, the processor can output the backlight values ​​of N backlight areas to the backlight control module, so that the backlight control module can light up the backlight units according to the backlight values ​​of the N backlight areas, thereby displaying the first target image.

[0114] S504. Perform contrast stretching processing on the pixels in the first target image that are within the target grayscale range to obtain a second target image, and display the second target image; the target grayscale range does not include the grayscale range corresponding to the background.

[0115] In some embodiments, when the processor determines that contrast stretching of the first target image is necessary, contrast stretching can be performed in the following manner:

[0116] In one possible implementation, the processor can employ a pre-trained stretching model to adjust the grayscale values ​​of pixels within the target grayscale range in the first target image to perform contrast stretching processing, thereby obtaining the second target image. The adjustment of the pixel grayscale values ​​includes increasing or decreasing the grayscale values ​​of the pixels.

[0117] In one possible implementation, the processor can determine the target grayscale range and stretching coefficient that need to be contrast stretched based on the statistical results of the grayscale histogram of the first target image, and adjust the grayscale values ​​of the pixels within the target grayscale range using the stretching coefficient to perform contrast stretching processing to obtain the second target image.

[0118] When the processor obtains the second target image, it can display the second target image. The specific display method is similar to the method of displaying the first target image, and will not be described in detail here.

[0119] The image processing method provided in this application divides the image to be displayed into N partitions corresponding to the backlight area, performs local dimming processing on the images of the N partitions to obtain a first target image, and backlight values ​​for the N backlight areas; determines whether the proportion of the number of pixels with grayscale values ​​less than a preset grayscale value in the first target image to the total number of pixels in the first target image is greater than a preset threshold; if not, displays the first target image; if so, performs contrast stretching processing on the pixels in the first target image that are within the target grayscale range to obtain a second target image, and displays the second target image; the target grayscale range does not include the grayscale range corresponding to the background. When the first target image is an image with poor contrast performance, contrast stretching is performed to obtain the second target image, thereby effectively improving the display effect of the second target image.

[0120] Based on the above embodiments, the following is combined with Figure 6 The method by which the processor determines the target grayscale range and stretching factor is further explained.

[0121] Figure 6 A flowchart illustrating the image processing method provided in the embodiments of this application. Figure 2 ,like Figure 6 As shown, it includes:

[0122] S601. Perform grayscale histogram statistics on the first target image, and obtain the grayscale distribution characteristics of the first target image based on the statistical results of the grayscale histogram.

[0123] In some embodiments, grayscale distribution features can refer to the distribution of the number of pixels at different grayscale levels in an image, such as grayscale range, grayscale peak value, grayscale variance, etc. Grayscale distribution features can be used to determine the contrast, brightness, dynamic range and other characteristics of an image.

[0124] S602. Based on the grayscale distribution characteristics, remove the grayscale range corresponding to the background in the first target image from the grayscale range corresponding to the first target image to obtain an initial grayscale range.

[0125] In some embodiments, when the processor obtains the grayscale distribution features, it can use a preset recognition algorithm to process the grayscale distribution features and identify the grayscale range corresponding to the background in the first target image. For example, the processor can use algorithms such as histogram peak detection algorithm and Gaussian mixture model algorithm to perform background recognition.

[0126] Since the first target image has poor contrast, if the grayscale corresponding to the background is included when performing contrast stretching, the stretched image will have abnormal brightness. When determining the grayscale stretching range, the processor can remove the grayscale range corresponding to the background. For example, if the grayscale distribution range of the first target image is determined to be 0-120 based on the grayscale distribution characteristics, and the grayscale distribution range of the background is 0-20, then the initial grayscale range is 21-120.

[0127] S603. Based on the grayscale distribution characteristics, determine the typical image corresponding to the first target image.

[0128] In some embodiments, a typical image may refer to a representative image of a class of images or a standardized image of that class of images, which can reflect the essential characteristics of a class of images.

[0129] When the processor acquires the grayscale distribution features of the first target image, it can search for a typical image in a preset typical image database that matches the grayscale distribution features of the first target image. Here, "matching" can mean that the grayscale distribution features of the first target image are the same or similar. For example, if the difference between the grayscale distribution features of the first target image and the grayscale distribution features of a typical image is less than a preset threshold, they can be considered similar.

[0130] In some embodiments, a preset typical image database may be stored in the memory of the display device, or in a cloud platform to which the display device is connected.

[0131] S604. Based on the preset grayscale range of the typical image, the initial grayscale range is corrected to obtain the target grayscale range.

[0132] In some embodiments, each typical image is provided with a corresponding grayscale range for contrast stretching. When the processor obtains a typical image corresponding to the first target image, it can use the grayscale range corresponding to the typical image to correct the initial stretching range corresponding to the first target image to obtain the target image.

[0133] For example, if the grayscale range of the typical image corresponding to the first target image is 10-50 and 80-100, and the initial grayscale range is 21-120, then the processor can take the intersection of the grayscale range corresponding to the typical image and the initial grayscale range as the target grayscale range (21-50, 80-100).

[0134] S605. Using a preset stretching algorithm, process the typical image and the target grayscale range to obtain the stretching coefficient corresponding to the first target image.

[0135] In some embodiments, the stretching coefficient is used to adjust the grayscale value of a pixel; the stretching coefficient is a linear stretching coefficient or a non-linear stretching coefficient.

[0136] In some embodiments, the processor can use the typical image, a preset stretching range and stretching coefficient of the typical image, and the target grayscale range as inputs to the preset stretching algorithm to obtain the stretching coefficient output by the stretching algorithm. For example, the preset stretching algorithm can be an adaptive histogram equalization algorithm, a dynamic range adjustment algorithm, etc.

[0137] S606. The gray values ​​of pixels in the first target image that are within the target gray range are adjusted using the stretching coefficient to obtain the second target image.

[0138] In some embodiments, when the processor obtains the stretching coefficient, it can use the stretching coefficient to adjust the grayscale value of each pixel within the target grayscale range.

[0139] For example, if the stretching factor is a linear stretching factor, then adjusting the grayscale value of each pixel within the target grayscale range can satisfy the following formula:

[0140] Y = a * X + b

[0141] Where a is the stretching coefficient, X is the grayscale value before stretching, Y is the grayscale value after stretching, and b is a constant.

[0142] If the stretching coefficient is a non-linear stretching coefficient (for example, the stretching coefficient is represented by a curve, with the horizontal axis representing the grayscale value before stretching and the vertical axis representing the grayscale value after stretching), then the adjusted grayscale value of each pixel can be calculated based on the curve.

[0143] In summary, the embodiments of this application use typical images to determine the range and stretching coefficient of the first target image that need to be stretched in contrast. Since there are few types of images that need to be stretched in contrast, only a small number of typical images are needed to fully cover them, which greatly reduces the storage pressure on the display device and can quickly achieve the stretching of the first target image in contrast.

[0144] Based on the above embodiments, the display device may also use a pre-trained stretching model to perform contrast stretching on the first target image.

[0145] For example, a contrast stretching model is invoked to perform contrast stretching processing on the first target image to obtain the second target image; the contrast stretching model is obtained by training an initial stretching model using a training dataset, the training dataset including a subset of sample images and a subset of target images; the sample images in the subset of sample images correspond one-to-one with the target images in the subset of target images, and the sample images carry the grayscale range to be stretched and the stretching coefficient; the stretching coefficient is determined based on the target image corresponding to the sample image.

[0146] The training process of the stretching model is described below:

[0147] Multiple sample images are prepared in advance to form a sample image set. The sample images cover a variety of different types of image scenes that require contrast stretching, and each image scene has multiple sample images.

[0148] Multiple target images are prepared in advance to form a target image set. The target images are images after contrast stretching of the sample images in the sample image set. That is, there is a one-to-one correspondence between the sample images in the sample image set and the target images in the target image set.

[0149] Each sample image is marked with the grayscale range that needs to be stretched, and the corresponding stretching coefficient, wherein the stretching coefficient is obtained by a stretching algorithm based on the target image and the grayscale range.

[0150] The sample image and the target image are input into an initial stretching model, which performs contrast stretching on pixels within the grayscale range according to the stretching coefficient of each sample image, resulting in a stretched image. The initial model compares the stretched image with the corresponding target image, calculates the corresponding loss function value, and adjusts the model parameters using a preset optimization algorithm based on the loss function value. This stretching process and loss function calculation are iteratively executed until the loss function value between the stretched image and the corresponding target image meets a preset value, at which point model training is complete. The initial stretching model can be a model built based on a neural network.

[0151] In some embodiments, the trained stretching model can be stored in the memory of the display device. After the processor performs local dimming processing on the first target image, if it determines that the first target image needs to be stretched, it can retrieve the stretching model from the memory to process the first target image and obtain the processed second target image.

[0152] For example, such as Figure 7 and Figure 8 As shown, Figure 7This is a typical night sky scene after local dimming; you can see that the stars are dimly visible. Figure 8 The image shows the result after contrast stretching. As you can see, the contrast is enhanced, the starry sky is more clearly defined, and the display effect is improved.

[0153] In some embodiments, when displaying the second target image, the display device may also determine whether the current display effect meets the user's expectations based on the user's operation.

[0154] For example, when displaying the second target image, a first prompt message is output; the first prompt message is used to prompt the user whether they are satisfied with the current display effect; if the received feedback message indicates that the user is not satisfied with the current display effect, the second target image is uploaded to a preset server; the second target image is used to update the contrast stretching model.

[0155] or,

[0156] When an adjustment instruction is received within a preset time period, the second target image is uploaded to a preset server. The adjustment instruction is used to adjust the brightness and / or contrast of the display screen.

[0157] For example, the display device can output the initial prompt information to the user via voice or notification message, such as... Figure 9 As shown, the screen displays "Are you satisfied with the current display effect?" If the user's "No" operation is received (i.e., the feedback information indicates that the user is not satisfied with the current display effect), the display device can upload the second target image to the preset server.

[0158] Alternatively, if the display device receives a user's instruction to adjust the brightness or contrast of the display screen within a preset time period while displaying the second target image, it can determine that the user is not satisfied with the current display effect, and then the display device can upload the second target image to a preset server.

[0159] In some embodiments, when the server receives the second target image, it can determine that the user is not satisfied with the stretching effect of the current stretching model on the second target image. The server can optimize the stretching model based on the second target image and send the optimized model to the display device.

[0160] For example, an update instruction is received; the update instruction is used to instruct the update of the contrast stretching model; data to be updated is read, the data to be updated includes update parameters of the contrast stretching model, or a new contrast stretching model; the contrast stretching model is updated using the update parameters, or the contrast stretching model is replaced using the new contrast stretching model.

[0161] The display device can receive update instructions from the server and update the stretching model based on the update instructions.

[0162] In some embodiments, the update instruction carries data to be updated, and the display device can read the data to be updated and update the stretching model based on the data to be updated.

[0163] In some embodiments, the update instruction carries the storage address of the data to be updated. The display device can read the data to be updated from the storage address and update the stretched model based on the data to be updated. Specifically, if the data to be updated is model parameters, the display device updates the parameters of the current model to the model parameters included in the data to be updated; if the data to be updated is a new model, the display device replaces the current model with the new model.

[0164] In some embodiments, to further enhance the display effect, the display device may also optimize the stretched second target image.

[0165] For example, image parameters of the second target image are obtained, including brightness and / or contrast; if the image parameters are not within a preset parameter range, the image parameters are adjusted using a preset adjustment coefficient, and the second target image after the image parameters are adjusted is displayed.

[0166] or,

[0167] The second target image is post-processed, and the post-processed second target image is displayed; the post-processing includes one or more of noise removal, sharpening, and color correction.

[0168] The preset parameter range and adjustment coefficients can be predefined in the processor based on a typical image corresponding to the second target image.

[0169] Based on the above embodiments, this application also provides an image processing apparatus, which can be applied to the processor in any of the above embodiments.

[0170] Figure 10 This is a schematic diagram of the structure of the image processing apparatus 100 provided in the embodiments of this application, as shown below. Figure 10 As shown, it includes:

[0171] The acquisition module 1001 is used to divide the image to be displayed into N partitions corresponding to the backlight area, perform local dimming processing on the images of the N partitions, and obtain a first target image, as well as the backlight values ​​of the N backlight areas.

[0172] Processing module 1002 is used to determine whether the proportion of the number of pixels in the first target image whose gray value is less than a preset gray value to the total number of pixels in the first target image is greater than a preset threshold.

[0173] The display module 1003 is configured to, if not, display the first target image; if yes, perform contrast stretching on pixels in the first target image that fall within the target grayscale range to obtain a second target image, and display the second target image; the target grayscale range does not include the grayscale range corresponding to the background. When displaying the first target image or the second target image, the corresponding backlight unit is controlled to emit light according to the backlight values ​​of the N backlight regions.

[0174] In some embodiments, the processing module 1002 is further configured to perform grayscale histogram statistics on the first target image, and obtain the grayscale distribution characteristics of the first target image based on the statistical results of the grayscale histogram; based on the grayscale distribution characteristics, remove the grayscale range corresponding to the background in the first target image from the grayscale range corresponding to the first target image to obtain an initial grayscale range; determine a typical image corresponding to the first target image based on the grayscale distribution characteristics; and correct the initial grayscale range based on the grayscale range preset by the typical image to obtain the target grayscale range.

[0175] In some embodiments, the processing module 1002 is further configured to process the typical image and the target grayscale range using a preset stretching algorithm to obtain a stretching coefficient corresponding to the first target image, wherein the stretching coefficient is used to adjust the grayscale value of the pixel; the stretching coefficient is a linear stretching coefficient or a non-linear stretching coefficient; and the grayscale value of the pixel in the first target image that is within the target grayscale range is adjusted using the stretching coefficient to obtain the second target image.

[0176] In some embodiments, the display module 1003 is further configured to invoke a contrast stretching model to perform contrast stretching processing on the first target image to obtain the second target image; the contrast stretching model is obtained by training an initial stretching model using a training dataset, the training dataset including a subset of sample images and a subset of target images; the sample images in the subset of sample images correspond one-to-one with the target images in the subset of target images, the sample images carrying the grayscale range to be stretched and the stretching coefficient; the stretching coefficient is determined based on the target image corresponding to the sample image.

[0177] In some embodiments, the processing module 1002 is further configured to output a first prompt message when displaying the second target image; the first prompt message is used to prompt the user whether they are satisfied with the current display effect; if the received feedback message indicates that the user is not satisfied with the current display effect, the second target image is uploaded to a preset server; the second target image is used to update the contrast stretching model; or, when displaying the second target image, if an adjustment instruction is received within a preset time period, the second target image is uploaded to a preset server, and the adjustment instruction is used to adjust the brightness and / or contrast of the display screen.

[0178] In some embodiments, the processing module 1002 is further configured to receive an update instruction; the update instruction is configured to instruct the updating of the contrast stretching model; read data to be updated, the data to be updated including update parameters of the contrast stretching model, or a new contrast stretching model; update the contrast stretching model using the update parameters, or replace the contrast stretching model using the new contrast stretching model.

[0179] In some embodiments, the display module 1003 is further configured to acquire image parameters of the second target image, the image parameters including brightness and / or contrast; if the image parameters are not within a preset parameter range, the image parameters are adjusted using a preset adjustment coefficient, and the second target image after image parameter adjustment is displayed; or, the second target image is post-processed, and the post-processed second target image is displayed; the image post-processing includes one or more of noise removal, sharpening, and color correction.

[0180] The image processing apparatus provided in this application embodiment can execute the image processing method in any of the above embodiments, and its principle and technical effect are similar, so they will not be described again here.

[0181] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. These modules can be implemented entirely in software via processing element calls; they can be fully implemented in hardware; or some modules can be implemented in software via processing element calls, while others are implemented in hardware. Each module can be a separate processing element, or it can be integrated into a chip within the device. Alternatively, it can be stored as program code in the device's memory, and its functions can be called and executed by a processing element. Furthermore, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. During implementation, each step of the above method or each of the above modules can be completed through integrated logic circuits in the processor element or through software instructions.

[0182] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0183] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0184] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0185] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0186] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0187] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0188] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0189] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0190] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A display device, characterized by comprising: The display device comprises: a display screen configured to display an image; a backlight unit configured to provide a backlight source for the display screen, the backlight unit being divided into N backlight regions, N being an integer greater than 1; and a processor connected to the display screen and the backlight unit respectively, the processor being configured to: divide an image to be displayed into N partitions corresponding to the backlight regions, perform local dimming processing on the images of the N partitions to obtain a first target image and backlight values of the N backlight regions, the local dimming processing being used to adjust the backlight values of the N backlight regions determined based on the image to be displayed and adjust pixel values of the images of the N partitions; determine whether a proportion of a number of pixels with a gray value less than a preset gray value in the first target image to a total number of pixels in the first target image is greater than a preset threshold value; if not, display the first target image; if yes, perform contrast stretching processing on pixels in the target gray range in the first target image to obtain a second target image, and display the second target image; the target gray range does not include a gray range corresponding to a background; the contrast stretching is used to increase or decrease the gray value of the pixels in the target gray range; wherein, when displaying the first target image or the second target image, the corresponding backlight unit is controlled to emit light according to the backlight values of the N backlight regions.

2. The display device of claim 1, wherein, The processor is configured to: perform gray histogram statistics on the first target image, and obtain a gray distribution feature of the first target image according to the statistical results of the gray histogram; remove a gray range corresponding to a background in the first target image from a gray range corresponding to the first target image according to the gray distribution feature to obtain an initial gray range; determine a typical image corresponding to the first target image according to the gray distribution feature; the typical image is used to represent a typical feature of an image type corresponding to the first target image; correct the initial gray range based on a preset gray range of the typical image to obtain the target gray range.

3. The display device of claim 2, wherein, The processor is configured to: perform processing on the typical image and the target gray range using a preset stretching algorithm to obtain a stretching coefficient corresponding to the first target image, the stretching coefficient being used to adjust the gray value of a pixel; the stretching coefficient is a linear stretching coefficient or a nonlinear stretching coefficient; adjust the gray value of a pixel in the target gray range in the first target image using the stretching coefficient to obtain the second target image.

4. The display device according to any of claims 1-3, characterized in that, The processor is configured to: The contrast stretching model is obtained by training an initial stretching model using a training data set, the training data set comprising a sample image subset and a target image subset, the sample images in the sample image subset and the target images in the target image subset corresponding one-to-one, the sample images carrying a gray scale range to be stretched and a stretching coefficient, the stretching coefficient being determined based on the target images corresponding to the sample images.

5. The display device of claim 4, wherein, The processor is configured to: output first prompt information when the second target image is displayed, the first prompt information being used to prompt whether the user is satisfied with the current display effect; if the received feedback information indicates that the user is not satisfied with the current display effect, upload the second target image to a preset server; the second target image is used to update the contrast stretching model; or, if an adjustment instruction is received within a preset time length when the second target image is displayed, upload the second target image to a preset server, the adjustment instruction being used to adjust the brightness and / or contrast of the display screen.

6. The display device of claim 5, wherein, The processor is configured to: receive an update instruction, the update instruction being used to instruct to update the contrast stretching model; read data to be updated, the data to be updated comprising an update parameter of the contrast stretching model or a new contrast stretching model; update the contrast stretching model using the update parameter or replace the contrast stretching model with the new contrast stretching model.

7. The display device according to claim 2 or 3, characterized by The processor obtains image parameters of the second target image, the image parameters comprising brightness and / or contrast; if the image parameters are not within a preset parameter range, adjusts the image parameters using a preset adjustment coefficient and displays the second target image after the image parameters are adjusted; or, performs image post-processing on the second target image and displays the second target image after the image post-processing; the image post-processing comprises one or more of noise removal, sharpening processing and color correction.

8. An image processing method characterized by, Applied to a display device, the display device comprising: a display screen configured to display an image; a backlight unit configured to provide a backlight source for the display screen, the backlight unit being divided into N backlight regions, N being an integer greater than 1; the method comprising: dividing an image to be displayed into N partitions corresponding to the backlight regions, performing local dimming processing on the images of the N partitions to obtain a first target image and backlight values of the N backlight regions, the local dimming processing being used to adjust the backlight values of the N backlight regions determined based on the image to be displayed and adjust pixel values of the images of the N partitions; determining whether a proportion of a number of pixels with a gray scale value less than a preset gray scale value in the first target image to a total number of pixels in the first target image is greater than a preset threshold value; if not, display the first target image; If so, pixels in the first target image within a target gray scale range are subjected to contrast stretching processing to obtain a second target image, and the second target image is displayed; the target gray scale range does not include a gray scale range corresponding to a background; the contrast stretching is used to increase or decrease gray scale values of pixels within the target gray scale range; When the first target image or the second target image is displayed, the light-emitting of the corresponding backlight unit is controlled according to the backlight value of the N backlight regions.

9. A storage medium, characterized by The storage medium has computer execution instructions stored therein, and the computer execution instructions are executed by the processor to implement the method in claim 8.

10. A computer program product, characterised in that, The computer program is executed by the processor to implement the method in claim 8.

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