A display control method and control device with a global dynamic backlight adjustment mechanism

Abstract

The application provides a display control method with a global dynamic backlight adjustment mechanism, comprising the following steps: a. determining a gain curve group corresponding to an input picture based on the absolute value difference between the sum average mean corresponding to the maximum value of the sub-pixel value of each pixel of the input picture and the statistical median of the maximum value of the sub-pixel value of each pixel, the average mean and the histogram corresponding to the sub-pixel value; b. performing picture compensation processing and backlight adjustment processing on the input picture based on the specific gain curve selected from the gain curve group. The application also provides a display control device with a global dynamic backlight adjustment mechanism. The technical scheme provided by the application ensures that the picture will not appear overflow distortion by adaptively selecting a gain curve, improves the picture contrast and ensures the display quality of the picture.

Description

Technical Field

[0001] This invention belongs to the field of chips, specifically the field of display driver chips, particularly for LCD display devices, and more specifically to a control method for backlight adjustment of LCD display devices, and a control method and corresponding control device for dynamically adjusting the backlight of LCD display devices. Background Technology

[0002] In existing liquid crystal displays (LCDs), most of the power consumption comes from the constant backlight required for the LCD screen. Therefore, to save power, the backlight brightness of the LCD screen needs to be adaptively adjusted according to the content displayed on the screen. By adjusting the backlight duty cycle (PWM) according to different content, the backlight brightness can be reduced, thereby achieving the goal of saving power.

[0003] The display effect is closely related to the backlight brightness of the LCD screen. A decrease in backlight will lead to a decrease in the brightness and contrast of the displayed image. Therefore, the image values ​​need to be adjusted accordingly during backlight adjustment to ensure the display quality. However, the current method of adjusting image values ​​is prone to numerical overflow, which can lead to a decrease in image contrast or even image distortion, greatly affecting the display quality.

[0004] Currently, existing technologies mainly include local dimming and global dimming. Local dimming adjusts the image in sections, allowing for better backlight control, but it requires a better backlight matrix and more complex dimming algorithms. Global dimming is simpler to implement than local dimming, can also adjust the backlight to reduce power consumption, and has lower requirements for the backlight matrix. Currently, the methods for globally adjusting the image values ​​of LCD screens are not ideal, and a better technical solution for backlight adjustment is needed. Specifically, there is a lack of a control method and device for global dynamic backlight adjustment. Summary of the Invention

[0005] To address the technical deficiencies of existing technologies, the present invention aims to provide a display control method and device with a global dynamic backlight adjustment mechanism. According to one aspect of the invention, a display control method with a global dynamic backlight adjustment mechanism is provided, which dynamically adjusts the input screen data of the display screen to generate adjusted output screen data. The method is characterized by comprising the following steps:

[0006] a. Based on the absolute difference between the summation average mean corresponding to the maximum sub-pixel value of each pixel in the input image and the statistical median value of the maximum sub-pixel value of each pixel, the average mean, and the histogram corresponding to the sub-pixel value, determine the gain curve group corresponding to the input image;

[0007] b. Based on the gain curve group, select a specific gain curve to perform image compensation processing and backlight adjustment processing on the input image; wherein, the gain curve group and the gain curve therein are pre-stored in a memory adapted to the display screen.

[0008] Preferably, step b, which involves performing image compensation processing on the input image, includes the following steps:

[0009] b1. Determine the maximum value among the sub-pixel values ​​of each pixel in the input image;

[0010] b2. Based on the maximum value, determine the predetermined output value corresponding to the maximum value from the gain curve, and calculate the gain gai n = the predetermined output value / the maximum value;

[0011] b3. The product of the gain gai n and the value of each sub-pixel is used as the output value of the pixel, thereby completing the image compensation processing of the input image.

[0012] Preferably, step b, which involves adjusting the background of the input screen, includes the following steps:

[0013] b1'. Calculate the curve step length step = a0*k0 + a1*k1… + an*kn;

[0014] Wherein, kn represents the number of pixel values ​​of different brightness levels of the image determined by the histogram, and an represents the displacement weight an corresponding to the brightness level of each interval determined by the histogram; wherein, different gain curve groups have different displacement weight values ​​an; wherein, the larger the step is, the closer the curve used in the background adjustment process is to the gain curve with a slope of 1 in the gain curve group.

[0015] Preferably, the intermediate value is confirmed through the following steps:

[0016] a1. Determine the maximum value of RGB for each sub-pixel in the input image, and sum all the maximum values;

[0017] a2. Calculate the mean value by performing a mean calculation on the summation result;

[0018] a3. Determine the initial median value mid_or i of the input screen using the histogram, and construct a median interval centered on the initial median value mid_or i. The interval is...

[0019] [mi d_or i-k1, mi d_or i+k1], obtain the maximum value max_mi d and the minimum value min_mi d within the median interval;

[0020] a4. Calculate the difference between the maximum value of the interval max_mid and the minimum value of the interval min_mid, de lta_min = max_mid – min_mid. When the difference de lta_min is greater than the threshold mid_th, the intermediate value mid_out is equal to the maximum value of the histogram statistics screen; otherwise, the intermediate value mid_out = mid_or i, where the threshold mid_th is equal to the average value mean / 4.

[0021] Preferably, the control method further includes the following steps:

[0022] iii. Determine the contrast level of the input image based on the absolute value difference, specifically including the following steps:

[0023] When the absolute value difference is less than the threshold dth1, it is determined to be a low contrast image and is set to contrast level 1.

[0024] When the absolute value difference is greater than or equal to the threshold dth1 and less than the threshold dth2, it is defined as contrast level 2;

[0025] When the absolute value difference is greater than or equal to the threshold dthn-1 and less than the threshold dthn, it is defined as contrast level n-1;

[0026] When the absolute value difference is greater than or equal to the threshold dthn, it is determined to be a high contrast image and is designated as contrast level n.

[0027] Preferably, the control method further includes the step of: if the input screen is an 8-bit screen of 0 to 255, then when the absolute value difference is 0 to 16, it is low contrast; when the absolute value difference is greater than 164, it is high contrast; and when the absolute value difference is 64 to 80, it is medium contrast.

[0028] Preferably, the control method further includes the following steps:

[0029] i v. Determine the brightness level of the input screen based on the mean value, specifically including the following steps:

[0030] When the average value is less than the threshold mth1, it is determined to be a low-brightness image and set to brightness level 1;

[0031] When the average value is greater than or equal to the threshold mth1 and less than the threshold mth2, it is defined as brightness level 2;

[0032] When the average value is greater than or equal to the threshold mthn-1 and less than the threshold mthn, it is defined as brightness level n-1;

[0033] When the average value is greater than or equal to the threshold mthn, it is defined as the brightness level n.

[0034] Preferably, if the input screen is an 8-bit screen of 0 to 255, then when the mean average is 0 to 32, it is low brightness; when the mean average is 224 to 255, it is high brightness; and when the mean average is 112 to 144, it is medium brightness.

[0035] Preferably, the gain curve group and the gain curves therein store the corresponding numerical gain values ​​through a LUT lookup table.

[0036] Preferably, the LUT lookup table also stores the global backlight adjustment value corresponding to each numerical gain curve.

[0037] Preferably, the gain curve set and the gain curves therein are stored in the memory by OTP programming.

[0038] According to another aspect of the present invention, a display control device with a global dynamic backlight adjustment mechanism is also provided, which dynamically adjusts the input screen data of the display screen to generate adjusted output screen data, characterized in that it includes the following devices:

[0039] A first processing device determines a set of gain curves corresponding to the input image based on the absolute difference between the mean sum of the maximum sub-pixel values ​​of each pixel in the input image and the statistical median of the maximum sub-pixel values ​​of each pixel, the mean sum, and the histogram corresponding to the sub-pixel values; and

[0040] The second processing device selects a specific gain curve based on the gain curve group to perform image compensation processing and backlight adjustment processing on the input image.

[0041] The gain curve set and the gain curves therein are pre-stored in a memory adapted to the display screen.

[0042] Preferably, the gain curve set and the gain curves therein are stored in the memory by OTP programming.

[0043] This invention provides a display control method, display control device, and corresponding circuit with a global dynamic backlight adjustment mechanism. It is used for adaptive control of backlight compensation and numerical gain, preventing image distortion caused by numerical overflow of image gain during backlight adjustment. This method ensures that the image does not experience overflow distortion by adaptively selecting the gain curve, while simultaneously improving image contrast and guaranteeing display quality. This invention is simple to implement, cost-effective, and effectively solves the aforementioned technical problems, possessing significant commercial value. Attached Figure Description

[0044] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0045] Figure 1 A flowchart illustrating a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention is shown.

[0046] Figure 2 A flowchart illustrating a display control method for a global dynamic backlight adjustment mechanism, according to a specific embodiment of the present invention, is shown.

[0047] Figure 3 A flowchart illustrating a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention is shown.

[0048] Figure 4 A flowchart illustrating a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention is shown.

[0049] Figure 5 A set of gain curves is shown in a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention.

[0050] Figure 6 Another set of gain curves is shown in a display control method for a global dynamic backlight adjustment mechanism according to a second embodiment of the present invention.

[0051] Figure 7 Another set of gain curves is shown in a display control method for a global dynamic backlight adjustment mechanism according to a third embodiment of the present invention.

[0052] Figure 8 Another set of gain curves is shown in the display control method of a global dynamic backlight adjustment mechanism according to the fourth embodiment of the present invention;

[0053] Figure 9The diagram illustrates the data calculation process of a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention.

[0054] Figure 10 The diagram illustrates the flow chart of the absolute value difference analysis of the average value and the median value in a display control method for a global dynamic backlight adjustment mechanism according to the first embodiment of the present invention.

[0055] Figure 11 This diagram illustrates an average value analysis process in a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention; and

[0056] Figure 12 The diagram shows a circuit structure schematic of a display control device for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention. Detailed Implementation

[0057] To better illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0058] Specifically, Figure 1 , Figure 2 , Figure 9 This diagram illustrates a flowchart of a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention. First, in step S101, a gain curve group corresponding to the input screen is determined based on the absolute difference between the summation average (mean) of the maximum sub-pixel values ​​of each pixel and the statistical median value of the maximum sub-pixel values ​​of each pixel, the mean, and the histogram corresponding to the sub-pixel values. Then, in step S102, a specific gain curve is selected based on the gain curve group to perform image compensation processing and backlight adjustment processing on the input screen. In the above steps, the gain curve group and the gain curves therein are pre-stored in a memory adapted to the display screen.

[0059] Combination Figure 2 , Figure 9 As will be understood by those skilled in the art in the embodiments shown, the display control method based on the global dynamic backlight adjustment mechanism provided by the present invention obtains the information required for mode selection through steps such as screen statistical summation and average index calculation, further selects and determines a mode, then determines a corresponding gain curve from the curve group based on the selected mode, and then performs compensation and adjustment processing for the global dynamic backlight of the screen based on the gain curve.

[0060] Furthermore, Figure 3This diagram illustrates a flow chart of a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention, particularly for... Figure 1 The specific processing measures for step S102 are as follows: First, proceed to step S201 to determine the maximum value among the sub-pixel values ​​of each pixel in the input image. Then, execute step S202 to determine a predetermined output value corresponding to the maximum value from the gain curve, and calculate the gain gin = the predetermined output value / the maximum value. Next, proceed to step S203 to use the product of the gain gin and each sub-pixel value as the output value of that pixel, thereby completing the image compensation processing of the input image.

[0061] In another preferred embodiment, Figure 1 The steps shown also include the following: Calculate the curve step length step = a0*k0 + a1*k1… + an*kn.

[0062] Wherein, kn represents the number of pixel values ​​of different brightness levels of the image determined by the histogram, and an represents the displacement weight an corresponding to the brightness level of each interval determined by the histogram.

[0063] Different gain curve groups have different displacement weight values ​​an.

[0064] The larger the step value, the closer the curve used in the background adjustment process is to the gain curve with a slope of 1 in the gain curve group.

[0065] Furthermore, in Figures 1 to 3 On this basis, Figure 4 This diagram illustrates a flow chart of a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention. Specifically, Figure 4A specific implementation method for calculating median values ​​is described. Specifically, first, step S301 is executed to determine the maximum RGB value of each sub-pixel in the input image, and then sum all the maximum values. Next, step S302 is executed to calculate the mean of the summation result. Then, step S303 is executed to determine the initial median value mid_or i of the input image using the histogram, and a median interval is constructed centered on the initial median value mid_or i, with the interval being [mid_or i-k1, mid_or i+k1]. The maximum value max_mid and the minimum value min_mid within the median interval are obtained. Finally, proceed to step S304, calculate the difference between the maximum value of the interval max_mid and the minimum value of the interval min_mid, de lta_min = max_mid – min_mid. When the difference de lta_min is greater than the threshold mid_th, the intermediate value mid_out is equal to the maximum value of the histogram statistics screen; otherwise, the intermediate value mid_out = mid_or i, where the threshold mid_th is equal to the average value mean / 4.

[0066] In combination with the above Figures 1 to 4 Those skilled in the art will understand that Figures 5 to 8 This diagram illustrates a set of gain curves used in the display control method of the global dynamic backlight adjustment mechanism, according to different embodiments of the present invention. In this technical solution, various sets of gain curves can be pre-stored, i.e. Figures 5 to 8 The gain curve group shown contains multiple gain curves. Based on different parameters, the most suitable gain curve can be selected, and the screen image can be processed such as backlight adjustment based on the selected gain curve.

[0067] Figure 10 This diagram illustrates a flowchart of the absolute value difference analysis process between the average and median values ​​in a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention. In conjunction with the above technical solution, determining the contrast level of the input screen based on the absolute value difference specifically includes the following steps:

[0068] When the absolute value difference is less than the threshold dth1, it is determined to be a low contrast image and is set to contrast level 1.

[0069] When the absolute value difference is greater than or equal to the threshold dth1 and less than the threshold dth2, it is defined as contrast level 2;

[0070] When the absolute value difference is greater than or equal to the threshold dthn-1 and less than the threshold dthn, it is defined as contrast level n-1;

[0071] When the absolute value difference is greater than or equal to the threshold dthn, it is determined to be a high contrast image and is designated as contrast level n.

[0072] Furthermore, Figure 11 The diagram illustrates an average value analysis process in a display control method for a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention. Determining the brightness level of the input screen based on the average value (mean) specifically includes the following steps:

[0073] When the average value is less than the threshold mth1, it is determined to be a low-brightness image and set to brightness level 1;

[0074] When the average value is greater than or equal to the threshold mth1 and less than the threshold mth2, it is defined as brightness level 2;

[0075] When the average value is greater than or equal to the threshold mthn-1 and less than the threshold mthn, it is defined as brightness level n-1;

[0076] When the average value is greater than or equal to the threshold mthn, it is defined as the brightness level n.

[0077] Figure 12 A circuit diagram of a display control device with a global dynamic backlight adjustment mechanism according to a first embodiment of the present invention is shown. Specifically, the display control device with a global dynamic backlight adjustment mechanism includes a first processing unit that determines a gain curve group corresponding to the input screen based on the absolute value difference between the summation average mean corresponding to the maximum sub-pixel value of each pixel of the input screen and the statistical median value of the maximum sub-pixel value of each pixel, the average mean, and the histogram corresponding to the sub-pixel values; and a second processing unit that selects a specific gain curve based on the gain curve group to perform screen compensation processing and backlight adjustment processing on the input screen; wherein the gain curve group and the gain curve therein are pre-stored in a memory adapted to the display screen. Further, those skilled in the art will understand that, corresponding to Figure 12As shown in the schematic diagram, the second processing device corresponds to the backlight adjustment module and the numerical gain module on the right, while the first processing device corresponds to the numerical statistics module, numerical calculation mode, and numerical analysis module on the left and in the middle. For example, the numerical statistics module is used to count the maximum sub-pixel value of each pixel in the input image, etc. The numerical calculation mode is used to calculate the mean summation of the maximum sub-pixel values ​​of each pixel in the input image, the absolute difference of the statistical median value of the maximum sub-pixel values ​​of each pixel, etc. The numerical analysis module determines the gain curve group corresponding to the input image based on the mean summation, the absolute difference of the statistical median value of the maximum sub-pixel values ​​of each pixel, the mean summation, and the histogram corresponding to the sub-pixel values, etc., which will not be elaborated here.

[0078] Furthermore, an objective of this invention is to provide a display control method with a global dynamic backlight adjustment mechanism, which adaptively controls backlight compensation and numerical gain according to different screen displays. In a preferred embodiment, the control method provided by this invention includes the following steps:

[0079] For each pixel in the input image, determine the maximum value of each sub-pixel's RGB values. After determining the maximum value of each pixel, sum the maximum values ​​and perform histogram statistics on the maximum values.

[0080] Those skilled in the art will understand that the maximum value histogram statistics are performed by storing the number of maximum values ​​for each pixel in registers. For example, for 8-bit pixel data, when the statistical step size is 1, 256 registers are used to store the number of occurrences of the maximum value values ​​from 0 to 255. When the statistical step size is 2, 128 registers are used to store the number of occurrences of the maximum value values ​​from 0 to 255. The index n corresponding to the value x is: n = (x + 1) / 2, and the index n is rounded down. And so on.

[0081] The sums are averaged to obtain the mean value. The median value of the image is determined based on the histogram statistics, thus determining the distribution of pixel values.

[0082] The median of the image is determined by first determining the initial median mi_or i using a histogram, then constructing a median interval centered on the initial median, with the interval being [mi_or i-k1, mi_or i+k1]. The maximum value max_mid and the minimum value min_mid within the median interval are obtained. The maximum and minimum values ​​can already be calculated using the histogram mentioned above, so there is no need to calculate and count them again.

[0083] When the difference between the maximum value of the interval max_mid and the minimum value of the interval min_mid is de l ta_min = max_mid – min_mid, which is greater than the threshold mid_th, the median mid_out is equal to the maximum value of the histogram statistics screen; otherwise, the median mid_out = mid_or i.

[0084] The threshold mi d_th is equal to the average value of the image, mean / 4;

[0085] Obtain the absolute difference between the summation average and the median of the histogram statistics.

[0086] The image is analyzed based on the absolute difference between the average and the median, the average value, and the histogram.

[0087] The method for analyzing the absolute value difference between the mean and the median is as follows:

[0088] When the absolute difference between the average value and the median value is less than the threshold dth1, it is determined to be a low-contrast image and is set to contrast level 1.

[0089] When the absolute difference between the mean and the median is greater than or equal to the threshold dth1 and less than the threshold dth2, it is defined as contrast level 2;

[0090] When the absolute difference between the mean and the median is greater than or equal to the threshold dthn-1 and less than the threshold dthn, it is defined as the contrast level n-1;

[0091] When the absolute difference between the average and the median is greater than or equal to the threshold dthn, it is determined to be a high-contrast image and is designated as contrast level n.

[0092] Furthermore, the average value analysis method is as follows:

[0093] When the average value is less than the threshold mth1, it is determined to be a low-brightness image and set to brightness level 1.

[0094] When the average value is greater than or equal to the threshold mth1 and less than the threshold mth2, it is defined as brightness level 2;

[0095] When the average value is greater than or equal to the threshold mthn-1 and less than the threshold mthn, it is defined as brightness level n-1;

[0096] When the average value is greater than or equal to the threshold mthn, it is defined as the brightness level n;

[0097] For an 8-bit image with a brightness of 0-255, an average value of 0-32 can be defined as low brightness, 224-255 as high brightness, and 112-144 as intermediate brightness.

[0098] The contrast threshold defined by the absolute difference between the average and the median can be determined based on the specific testing conditions of the display device.

[0099] The histogram analysis is based on contrast and brightness levels, and its analysis method is as follows: Figures 5-7 The three sets of gain curves are shown in the example:

[0100] The gain curve is used to compensate for the image based on the selected gain curve, and the maximum value data_in corresponding to each pixel value in the image is mapped to a predetermined output value data_out according to the curve. The image pixel value is the maximum value of the RGB sub-pixel value in each pixel value.

[0101] The gain gai n of the current pixel value is calculated based on the predetermined output value and the maximum value data_in, and then applied to all sub-pixel values ​​of the current pixel value.

[0102] gai n = d_out / d_i n;

[0103] r_out=r*gai n

[0104] g_out = g * g_i n

[0105] b_out = b*gai n.

[0106] For example, input [r,g,b] = [128,50,76];

[0107] The maximum value for RGB is 128, i.e., data_i n = 128;

[0108] Based on the curve lookup table, when data_i n = 128, data_out = 152;

[0109] Therefore, the gain gai n = 152 / 128 = 1.1875;

[0110] therefore,

[0111] r_out=r*gai n=128*1.1875=152;

[0112] g_out=g*gai n=50*1.1875=53

[0113] b_out=b*gai n=76*1.1875=90;

[0114] The Figures 5-7 Each of the three sets of curves has K numerical gain curves, and the corresponding numerical gain values ​​of the K numerical gain curves are stored in a LUT lookup table; the LUT lookup table also stores the global backlight adjustment value corresponding to each numerical gain curve.

[0115] Because for display devices, once the LUT lookup table is determined, the values ​​do not need to be modified. Therefore, the corresponding gain curves in the LUT lookup table and the global backlight adjustment values ​​corresponding to each gain curve can be programmed via OTP.

[0116] The numerical gain curve is a numerical mapping from data_in to data_out. For 8-bit pixel values, each gain curve stores 256 numerical gain values ​​and a global backlight adjustment value corresponding to one gain curve.

[0117] The number of pixel values ​​at each gray level is determined by using a histogram. The range is divided according to the average value threshold mthn. The corresponding brightness level is determined according to the range, and the number of pixel values ​​kn at the brightness level is obtained.

[0118] If the image is determined to be low brightness and high contrast, it can be positioned as... Figure 7 The gain curve group is used to further locate the specific gain curve based on the brightness level and contrast.

[0119] The low brightness determination method is that when the brightness level is equal to 1, it is determined to be low brightness;

[0120] The high contrast ratio determination method is that when the contrast ratio level is equal to n, it is determined to be high contrast ratio;

[0121] The initial gain curve is determined by the brightness. The lower the brightness, the further the maximum gain value of the corresponding low grayscale curve is from the slope of 1.

[0122] The number of pixel values ​​at different brightness levels in the image is determined by using a histogram. Different displacement weights an are determined based on the brightness level corresponding to each brightness interval. The closer the brightness is to the middle brightness, the larger the weight value, and the closer the maximum gain value of the curve is to the slope of 1.

[0123] The final moving step size is:

[0124] step=a0*k0+a1*k1…+an*kn;

[0125] The larger the step size, the closer the maximum gain value of the curve is to the slope of 1.

[0126] The specific curve is determined by moving the curve by a corresponding step size based on the initial curve, with the direction of movement being closer to the slope of the maximum gain value.

[0127] Each unit step corresponds to a curve. When the step is greater than the number of curves, the curve selected is the one with the maximum gain value closest to the slope of 1.

[0128] If the image is determined to have mid-range brightness and low contrast, then it is positioned as... Figure 6 The gain curve group is used to further locate the specific gain curve based on the brightness level and contrast.

[0129] The initial gain curve is determined by the brightness. The closer the average brightness is to the grayscale value of 128, the further the maximum gain value of the corresponding curve is from the slope of k=1.

[0130] Different displacement weights bn are determined based on the brightness levels corresponding to the brightness of each interval. The closer the brightness is to low or high brightness, the larger the weight value, and the closer the maximum gain value of the curve is to the slope of 1.

[0131] step=b0*k0+b1*k1…+bn*kn;

[0132] The larger the step size, the closer the maximum gain value of the curve is to the slope of 1.

[0133] The specific curve is determined by moving the curve by a corresponding step size based on the initial curve, with the direction of movement being closer to the slope of the maximum gain value.

[0134] Each unit step corresponds to a curve. When the step is greater than the number of curves, the curve selected is the one with the maximum gain value closest to the slope of 1.

[0135] If brightness and contrast are not clearly determined, or if pixels in the histogram are evenly distributed, then the location is... Figure 5 The gain curve set is used to further determine the specific gain curve based on the brightness.

[0136] For the remaining brightness and contrast ranges, different gain curves are constructed by shifting the midpoint of the curve, such as... Figure 8 As shown.

[0137] Another object of the present invention is to provide a display control circuit with a global dynamic backlight adjustment mechanism, the control circuit including a numerical statistics module, a numerical calculation module, a numerical analysis module, a curve and backlight storage module, a backlight adjustment module, and a numerical gain module.

[0138] The numerical statistics module includes pixel value summation and histogram statistics; the numerical calculation module includes summation and average value calculation, median value calculation, and absolute value difference between average and median value calculation; the numerical analysis module includes mean value judgment, absolute value difference judgment, and histogram analysis; the curve and backlight storage module stores multiple sets of gain curves and the global backlight adjustment values ​​corresponding to each gain curve.

[0139] Compared to existing technologies, this technical solution pre-stores multiple sets of numerical gain curves. It calculates the average, median, and histogram pixel value distribution of the image in real time. Based on the average value, the absolute difference between the average and median values, and the histogram pixel value distribution, it analyzes the current image's brightness and contrast status. Depending on the image status, a gain curve is selected to determine the numerical gain and backlight compensation. The gain curve constructed by this technology does not cause data overflow, thus ensuring that the image does not experience overflow distortion. Furthermore, this technology adaptively selects curves based on the image's brightness and contrast, improving the display contrast and ensuring the image's display quality.

[0140] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A display control method with a global dynamic backlight adjustment mechanism, which dynamically adjusts the input screen data of the display screen to generate adjusted output screen data, characterized in that, Includes the following steps: a. Based on the absolute difference between the summation average mean corresponding to the maximum sub-pixel value of each pixel in the input image and the statistical median value of the maximum sub-pixel value of each pixel, the average mean, and the histogram corresponding to the sub-pixel value, determine the gain curve group corresponding to the input image; b. Based on the group of gain curves, select a specific gain curve to perform image compensation processing and backlight adjustment processing on the input image; The gain curve set and the gain curves therein are pre-stored in a memory adapted to the display screen.

2. The control method according to claim 1, characterized in that, Step b, which involves performing image compensation processing on the input image, includes the following steps: b1. Determine the maximum value among the sub-pixel values ​​of each pixel in the input image; b2. Based on the maximum value, determine the predetermined output value corresponding to the maximum value from the gain curve, and calculate the gain = the predetermined output value / the maximum value; b3. The product of the gain and the value of each sub-pixel is used as the output value of the pixel, thereby completing the image compensation processing of the input image.

3. The control method according to claim 1 or 2, characterized in that, Step b, which involves adjusting the background of the input screen, includes the following steps: b1'. Calculate the curve step length step = a0*k0 + a1*k1… + an*kn; Wherein, kn represents the number of pixel values ​​of different brightness levels of the image determined by the histogram, and an represents the displacement weight an corresponding to the brightness level of each interval determined by the histogram. Among them, different gain curve groups have different displacement weight values ​​an; The larger the step value, the closer the curve used in the background adjustment process is to the gain curve with a slope of 1 in the gain curve group.

4. The control method according to any one of claims 1 to 3, characterized in that, The intermediate value is confirmed through the following steps: a1. Determine the maximum value of RGB for each sub-pixel in the input image, and sum all the maximum values; a2. Calculate the mean value by performing a mean calculation on the summation result; a3. Determine the initial median value mid_ori of the input screen through the histogram, and construct a median interval with the initial median value mid_ori as the center. The interval is [mid_ori-k1, mid_ori+k1], and obtain the maximum value max_mid and the minimum value min_mid within the median interval. a4. Calculate the difference between the maximum value of the interval max_mid and the minimum value of the interval min_mid, delta_min = max_mid – min_mid. When the difference delta_min is greater than the threshold mid_th, the intermediate value mid_out is equal to the maximum value of the histogram statistics screen. Otherwise, the intermediate value mid_out = mid_ori, where the threshold mid_th is equal to the average value mean / 4.

5. The control method according to claim 4, characterized in that, It also includes the following steps: i. Determine the contrast level of the input image based on the absolute value difference, specifically including the following steps: When the absolute value difference is less than the threshold dth1, it is determined to be a low contrast image and is set to contrast level 1. When the absolute value difference is greater than or equal to the threshold dth1 and less than the threshold dth2, it is defined as contrast level 2; When the absolute value difference is greater than or equal to the threshold dthn-1 and less than the threshold dthn, it is defined as contrast level n-1; When the absolute value difference is greater than or equal to the threshold dthn, it is determined to be a high contrast image and is designated as contrast level n.

6. The control method according to claim 5, characterized in that, It also includes the following steps: if the input image is an 8-bit image of 0 to 255, then when the absolute value difference is 0 to 16, it is low contrast; when the absolute value difference is greater than 164, it is high contrast; and when the absolute value difference is 64 to 80, it is medium contrast.

7. The control method according to any one of claims 4 to 6, characterized in that, It also includes the following steps: ii. Determine the brightness level of the input screen based on the mean value, specifically including the following steps: When the average value is less than the threshold mth1, it is determined to be a low-brightness image and set to brightness level 1; When the average value is greater than or equal to the threshold mth1 and less than the threshold mth2, it is defined as brightness level 2; When the average value is greater than or equal to the threshold mthn-1 and less than the threshold mthn, it is defined as brightness level n-1; When the average value is greater than or equal to the threshold mthn, it is defined as the brightness level n.

8. The control method according to claim 7, characterized in that, If the input image is an 8-bit image of 0 to 255, then when the mean value is 0 to 32, it is low brightness; when the mean value is 224 to 255, it is high brightness; and when the mean value is 112 to 144, it is medium brightness.

9. The control method according to any one of claims 1 to 8, characterized in that, The gain curve group and the gain curves therein are stored in a LUT lookup table to store the corresponding numerical gain values.

10. The control method according to claim 9, characterized in that, The LUT lookup table also stores the global backlight adjustment value corresponding to each numerical gain curve.

11. A display control device with a global dynamic backlight adjustment mechanism, which dynamically adjusts the output screen data based on the input screen data to generate adjusted output screen data, characterized in that, Includes the following devices: A first processing device determines a set of gain curves corresponding to the input image based on the absolute difference between the mean sum of the maximum sub-pixel values ​​of each pixel in the input image and the statistical median of the maximum sub-pixel values ​​of each pixel, the mean sum, and the histogram corresponding to the sub-pixel values; and The second processing device selects a specific gain curve based on the gain curve group to perform image compensation processing and backlight adjustment processing on the input image. The gain curve set and the gain curves therein are pre-stored in a memory adapted to the display screen.

12. The control method according to any one of claims 1 to 10 and / or the control device according to claim 11, characterized in that, The gain curve set and the gain curves therein are stored in the memory using OTP programming.

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