TW200525480A - Method and device of compensating brightness for LCD - Google Patents

Abstract

A method of compensating brightness for LCD includes measuring the original gamma curve of LCD panel, predeterminating a target gamma curve, inputting an initial gray level to figure out the brightness matching on the target gamma curve, finding out an adjusted gray level performing the brightness by the original gamma curve, and repeating above steps to result a lookup table having a plurality of proportion arrays. Thereafter the method further includes calculating the amount distribution of the input gray levels of the image, selecting a matching proportion array from the lookup table according proportion of the dark region and the bright region, substituting the adjusted gray levels for the input gray levels, and outputting the adjusted gray levels to adjust the signal strength and improve image performance. A device is also claimed. The method and device of compensating brightness for LCD are applicable to image adjustment of various LCD or similar displays.

Description

200525480 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a method and a device for adjusting the brightness compensation of an input device, particularly a method and device, which are suitable for image adjustment of a good image product f . Liquid sa display or similar display [Previous technology] ^ ^ The popularity of liquid crystal displays and the advantages of high image quality, but if it has low power consumption, weight and wide computer screen, it is gradually replaced: for digital TV, notes The mainstream of the type of electric display industry, autumn 3 cathode ray tube (CRT) = coefficient, dielectric constant and elasticity coefficient ^ characteristics of the two sons, such as the problem of long time delay and afterglow phenomenon / night crystal display will The image of the image with a painful device is not bright; the second f "is in CRT, liquid.;: The image is like a night scene, then the display produces: Title: If the rotation screen belongs to a darker viewer, the details of the image cannot be seen, ^ Brightness or contrast appears to be insufficient. ^ Images, such as those taken under backlight conditions. F The input daylight surface has more grayscale values with excessive contrast, making the daylight surface brighter and darker than the daylight image. In both areas, the daytime area cannot be displayed / the area is darker, and the brighter area is set with a brightness contrast adjustment button \ Γ! Tired layering, usually the display and contrast make the image clearer and more colorful. Adjust the brightness of the image manually For dynamic image viewing, it is very numb, but 'this manual adjustment is fast and diverse, with a single brightness and contrast,' which is a moving image. Therefore, it is difficult to adapt to various scene images through the internal unit gas 2 of the display. The layers of the picture are more obvious.

No. 08 200525480 V. Description of the invention (2) Please refer to the adjustment method. When the original gamma curve is raised on the driver, it will be improved relatively. However, this is not displayed on the display. 2. Each display method is not available. ; Go with its [invention of the present invention 'consideration of the display' use of gray-scale value books' for good display applications for the lack of flexibility in view of this device, content] invention of the liquid crystal display of the image of the invention's comparison table 1 picture, the conventional gray-level brightness control system determines that the line is adjusted to adjust the brightness of the display. The internal characteristics of the power consumption increaser and the panel characteristics are the same as the panel characteristics. The development of this case is based on improving the above technology The overall gamma of the device image is also improved. The disadvantages of control and addition are adjusted. The disadvantages mentioned in the picture are adjusted to enhance the image. Through one gamma, when the voltage on the LCD display is insufficient or the contrast is insufficient, the curve is about to gamma. Mm voltage value | makes the shirt image contrast and brightness obtaining device to control the voltage change and make the source consume. The single characteristic helmet of the control device, the ability to control the image appears to provide a novel brightness compensator. The main purpose is to provide _ one bet two Λ to provide a novel brightness compensator panel features, in order to decorate / Pin 1 shell quality.改 The method of processing the image signal is modified to provide another simple purpose. _ ^ A novel brightness compensation method corresponding to 'quickly obtain the appropriate brightness performance. Tune 2 is to provide a novel quality effect. Wide speed output adjustment gray scale. Good value, can be used for all kinds of LCD display surface

Page 10 200525480 V. Description of the invention (3) In order to achieve the above-mentioned invention purpose, the method of this case includes: (1) the original gamma curve of the measurement panel; (2) setting a target gamma curve; (3) entering a The initial grayscale value obtains the brightness corresponding to the target gamma curve. Find the adjusted grayscale value representing the Brahma on the original gamma curve. (4) Repeat the steps (2) to (3) above to generate a complex array of initial grayscale values. Value and complex array to adjust the grayscale value, summarize the complex array to adjust the grayscale value into a proportional array;

(5) Repeat the above steps (2) to (4) to generate a complex array scale array under different target curves to make a comparison table; (6) Calculate the number distribution of the input grayscale values of the image; (7) Calculate the dark Scale ratio and light scale ratio; (8) Select a corresponding scale array from the dark scale comparison table according to the size of the dark scale ratio, and replace the input gray scale value with the adjusted gray scale value in the scale array; (9) according to the light The scale scale selects a corresponding scale array from the brightness scale comparison table, and adjusts the gray scale value ^ gray scale value within the scale array; and η ^ Λ

(1 0) f Adjust the gray scale value to adjust the signal strength and quality. In the present invention, the device for performing the above method includes: a color gradation distribution analysis unit for receiving data; and two, inputting the number of distribution of the gray gradation value to obtain the color gradation distribution energy;

200525480

V. Explanation of the invention (4) A look-up table storage unit for storing the look-up table; a color-gradient calculation unit for calculating, and converting numbers to LUT intensity to correspond to the "Zhao table" conversion function * Example array adjustment "Gray level value replacement" is used to adjust the intensity of the input signal source to obtain better image quality. After detailed descriptions, the entity will explain the details and make it clearer. Take CXI as an example. ο Comparison ratio ftilτ-Η The quantity is one of two, the number is one, the value is the range of the reading range, the gray ash, the ginseng, the gray gradation range, and the total application is like a gray gradation. [Yizhi will set the total hair four to set the example in the latter example, the ratio of the actual order of Shi Fanfan around __ each lieutenant general front 6, face it, in Fan 7 ancient α day, 1, The value of the wall is shown in Figure 22. The second-order gray in the shader area of the fan zone is shown in the stepped area. The gray is bright and it is displayed in the dark step. The crystal color is bright. The 6 liquid will be the 5 range. In order to set the second order t, it is worth to enclose it to the gray i order, the range area ο a b gray meter's norm order value ο each of the dark orders under the unified system 1 4 calculation The number of gray and four dark cases is determined, and then the number of grays is determined, and then the number of grays is counted. The total number of 4 orders accounts for 2 grays. 4 The total number of 2 orders accounts for 3 to 8. 2 of the order __ The number of gray numbers. The first order and two bright regions refer to the dark cases of the order system. The example is better than the brighter than the better: How to set up and build a method like Fang Mingqi said, “Let ’s show examples and apply the best evidence to the reality, according to the same reason.” The 3rd page reader of the bright picture, please show the crystal Liquid line Quma. Jia Shiyuan-The device that shows the surface of the plate shows the crystal liquid measurement first;

Page 12 200525480 V. Description of the invention (5) (2) Set a target gamma curve 1 1; (3) Enter an initial gray level value X1 (label 1 2) to obtain the brightness Y1 corresponding to the target gamma curve 1 1 (Label 1 3), find the adjusted gray level value X 2 (label 14) representing the brightness on the original gamma curve 10, and (4) repeat the steps (2) to (3) above to generate a complex array of initial gray levels The value X i and the complex array adjustment gray level value X 2, and the complex array adjustment gray level value is summarized into a proportional array; and

(5) Repeat steps (2) to (4) above to generate a complex array proportional array under different target curves to make a comparison table. As shown in Figure 4, in terms of the display resolution of 10 bits, the dark level comparison table 41 and the light level comparison table 4 2 are respectively designed according to the dark level and the light level region, and the dark level control table 41 is selected. 8 sets of initial grayscale values 4 3 and a proportional array group 4 containing 6 sets of proportional arrays, and a light-level comparison table 4 2 Selects 8 sets of initial grayscale values 4 3 ′ and a proportional array group containing 7 sets of proportional arrays 4 4 ′ Each scale array group 4 4 and 4 4 ′ includes adjusted gray scale values 4 6 and 4 6 ′ corresponding to the initial gray scale values 4 3 and 4 3 ′.

After the image data is input, calculate the number distribution of the input grayscale values of the image to obtain the color gradation distribution map as shown in Figure 2. Calculate the dark scale ratio and the bright scale ratio, respectively. Select a corresponding proportional array in the proportional array group 1 of 4. If the dark scale ratio is higher, PII chooses the stronger proportional array in the dark scale comparison table 4 1 of the dark step comparison table 4 1 as shown by reference number 4 5 It is shown that the corresponding method of the dark scale ratio and the dark scale ratio table in Table 41 is to substitute the dark scale ratio into a dark scale conversion function to obtain a

Page 13 200525480 V. Description of the invention (6) Dark level LUT intensity, where the dark level conversion function is the greater the LUT intensity, the stronger the proportional matrix 6 in 4 4 is to replace the input gray level value; according to the ratio in Table 4 2 Array, j If the brighter ratio is higher, the stronger ratio is selected in the matrix shell table. Table 4 The ratio of a brighter conversion function to obtain the degree = F 2 (brighter ratio: the higher the brighter ratio, the brighter the ratio. The intensity corresponds to the adjusted gray scale value of the proportional array. The gray scale value after adjustment is adjusted to output the dark level LUT intensity I white LU 丄 5 to degrees ==: p increasing function, that is, dark level 1 (if the dark level scale has an image plane scale array 4 The gray scale value and output between the 7 and bright gray scale values are shown in the input and output curves of zone 5 respectively. The curve 5 1 will be higher than the input gray scale value and the output will be lower than the slope of the straight 5 4. 5 5 The intensity of this dark level LU will be repeated in a straight line corresponding to the higher j, the dark level column, and the ^ scale array group of the proportional array is the same, according to the grayscale value of the light level ratio 4 groups 4 4 Select a pair of sizes from Brightness to Brightness in Table 4 2 ratio; two-scale array, column, such as No. 4 5, as shown in Lenu 4 4. The corresponding method of the array is: 1st-order ratio and a bright-order L L T intensity, = dagger ratio substituted into ', where the bright-order conversion function system? All LU Dingqiang-order LU The greater the intensity of D is the increasing function, group 4 4, ^% ^ f this order L · U D value 4 β, a stronger proportional array, and replace the gray level value with this, and finally, it is $ the whole signal intensity Improve the image quality. ^ The 5th scale ratio corresponds to the dark level comparison table 4 1 == Table 4 2 scale ratio array 4 7, which can be obtained by 2 interpolation operations for each map user, and the grayscale value input is as _ ^ ' Among them, the adjusted dark-level region and the light-level gradient ^ are 5 1 and 5 2. The input of the dark-level region is a straight line 5 3 of gray ^ 1, and the straight line 5 3 represents the line ^ value of the light-level region's input-output curve 5 2 ^ 3 'and the critical points of the curves 5 1 and 5 2 are connected to each other' curve 5 1, 5 2 and the straight line

I 200525480 V. Description of the invention (7) 5 6 constitutes a new input and output relationship of image signal adjustment. From this, it can be seen that if the dark-level comparison table is provided with a group P dark-level ratio array, and the light-level comparison table is provided with a Q group bright The order proportion array can be obtained by arranging and combining PXQ group proportion array, that is, there will be input and output curves for PXQ adjustment, so there are many choices and application flexibility. In addition, the level of the lookup table can be set according to the requirements of the resolution of the display. If the input gray level value is 10 bit and the scale array is set to 12 bit display value, the output gray level value is 1 2 bit, so Only the order of the lookup table needs to be changed to apply to different displays, which is extremely industrially applicable.

Please refer to FIG. 6. The device for performing the above method in the present invention includes: a color level distribution analysis unit 6 1 for receiving image signals and counting the number of distributions of each input gray level value to obtain a color level distribution state ; A lookup table storage unit 6 2 for storing the lookup table; and a color scale operation unit 6 3 for calculating the color scale ratio, and substituting the conversion function into the LUT intensity to correspond to the ratio array in the lookup table, so as to Adjust the grayscale value in the scale array instead of inputting the grayscale value and outputting it; so as to adjust the intensity of the input signal source to obtain better image quality.

Therefore, the present invention has the following advantages: 1. Improves the shortcomings of the brightness and contrast of the traditional liquid crystal display. After the image is strengthened, it becomes more contrasty and colorful. 2. The application of the method of the present invention is not limited to the characteristics of a single panel. The gamma curve characteristics of different panels can be measured to make a special comparison table.

Page 15 200525480 V. Description of the invention (8) The image adjusted according to this comparison table can better express the color level. 3. Using the characteristics of the comparison table, the calculation is simple regardless of the corresponding or interpolated grayscale values. It is simple and fast, and the time to correct the image signal is greatly shortened, which makes the image appear to be corrected to the target brightness more quickly. 4. The number of proportional arrays in the comparison table can be set according to requirements. If the number of groups is larger, the more grayscale values can be adjusted. Therefore, the choice is diverse and the application flexibility. 5. The order of the comparison table can be set according to the requirements of the resolution of the display. It can be applied to a variety of displays with different gray levels, which is widely used. In summary, the present invention can indeed achieve the intended purpose, and provide a novel method and device for compensating the brightness of a liquid crystal display, which is of great industrial use value, and filed a patent application in accordance with the law.

Page 16 200525480 Schematic description 『Schematic Explanation』 The first diagram is a schematic diagram of the conventional technique of increasing the gamma voltage value to enhance the image. Figure 2 is a schematic diagram of a color gradation distribution image. FIG. 3 is a schematic diagram of the original gamma curve and the target gamma curve of the brightness compensation method and device of the liquid crystal display according to the embodiment of the present invention. FIG. 4 is a schematic diagram of a comparison table of the brightness compensation method and the device of the liquid crystal display according to the embodiment of the present invention.

FIG. 5 is a schematic diagram of inputting and outputting grayscale values of the brightness compensation method and the device of the liquid crystal display according to the embodiment of the present invention. FIG. 6 is an image processing flowchart of the brightness compensation method and the device of the liquid crystal display according to the embodiment of the present invention. 『Schematic Symbol Explanation』

2 1 Dark level region 2 2 Light level region 2 3 Number of gray levels in the dark level region 2 4 Number of gray levels in the light level region 1 0 Original gamma curve 1 1 Standard gamma curve 1 2 Initial gray level value X 1 1 3 Brightness Y 1 1 4 Adjust gray level value X 2 4 1 Dark level

Page 17 200525480 Brief description of the diagram 4 2: Bright level comparison table 4 3, 4 3 ′: Initial gray level values 4 4, 4 4 ′ ·· Proportional array group 4 5, 4 5 ′: Strength direction of the proportional array 4 6, 4 6 ': Adjust the grayscale value 4 7: The proportion array in the dark level comparison table 4 7': The proportion array in the light level comparison table 1 3 4 6 1 2 3 5 5 5 5 6 6 6 2 5 line level photo level 5 oblique 5 straight color to color value level gray output line input curve is equal to the output value input level input gray area input level input light C and line area straight point boundary dark 1 Pro: for: unit Analysis and distribution

Page 18

Claims (1)

200525480 6. Scope of patent application 1. A method for compensating the brightness of a liquid crystal display, including: (1) the original gamma curve of the measurement panel; (2) setting a target gamma curve; (3) entering an initial grayscale value to get the corresponding Based on the brightness of the target gamma curve, find the adjusted grayscale value representing the brightness on the original gamma curve (4) Repeat the steps (2) to (3) to generate the initial grayscale value of the complex array and adjust the grayscale of the complex array Value, the grayscale values of the complex array are reduced to a proportional array; (5) Repeat the above steps (2) to (4) to generate a complex array scale array under different target curves to make a comparison table; (6) Calculate the number distribution of the input grayscale values of the image; (7) Calculate the dark Scale ratio and light scale ratio; (8) Select a corresponding scale array from the dark scale comparison table according to the size of the dark scale ratio, and replace the input gray scale value with the adjusted gray scale value in the scale array; (9) Select a corresponding scale array from the brightness comparison table according to the size of the brightness scale, and replace the input gray scale value with the adjusted gray scale value in the scale array; and (1 0) change the adjusted gray scale value Output to adjust the signal strength to improve the image quality; to adjust the strength of the input signal source to obtain better image quality. 2. The brightness compensation method of the LCD as described in item 1 of the scope of patent application Page 19, 200525480 6. The method of applying for a patent scope, in which the dark scale ratio refers to the ratio of the number of gray scales in the dark scale area to the total number of gray scales, and the range of the dark scale area is a range below one ratio of the total gray scale range; Brightness ratio refers to the ratio of the number of gray scales in the light gray scale to the total number of gray scales, and the range of the light gray scale area is a range above one percentage of the total gray scale range. 3. The brightness compensation method for a liquid crystal display as described in item 2 of the scope of the patent application, wherein the range of the dark range is a quarter of the gray range before the total gray range; the range of the bright range is four after the total gray range. One-half gray scale range. 4. The brightness compensation method for a liquid crystal display according to item 1 of the scope of patent application, wherein the dark level comparison table is an array composed of a plurality of input gray level values and a complex array proportional array, and each input gray level value can be proportional to The array corresponds to an adjusted grayscale value; the light level comparison table is an array composed of a plurality of input grayscale values and a complex array proportional array. Each input grayscale value can be mapped to an adjusted grayscale value in the proportional array. . 5. The brightness compensation method for a liquid crystal display as described in item 1 of the scope of the patent application, wherein the corresponding method of the dark step ratio and the proportional array is to substitute the dark step ratio into a dark step conversion function to obtain a dark step LUT intensity, that is, a dark step LUT. Intensity = F i (dark scale ratio), the intensity of this dark scale LUT is mapped to the scale array in the dark scale comparison table, and the adjusted gray scale value in the scale array is used instead of the input gray scale value; The corresponding method is to substitute the brightness level ratio into a brightness level conversion function to obtain a brightness level LUT intensity, that is, brightness level LUT intensity = F 2 (brightness ratio), and corresponding this brightness level LUT intensity to the brightness level comparison table. Page 20 200525480 VI. Patent Application Proportional Array. Use this to adjust the grayscale value in the proportional array instead of inputting the grayscale value. 6. The method for compensating the brightness of a liquid crystal display as described in item 5 of the scope of the patent application, wherein the dark-level and bright-level conversion functions are an increasing function, that is, the higher the dark-level and bright-level ratios, the dark-level and bright-level LUT are. The greater the intensity. 7. The brightness compensation method for a liquid crystal display as described in item 1 of the scope of patent application, wherein the grayscale values between the grayscale values are obtained by interpolation. 8. A brightness compensation method for a liquid crystal display, comprising: (1) calculating the number distribution of the input grayscale values of an image; (2) calculating the dark scale ratio and the bright scale ratio separately; _ (3) changing the dark scale according to the size of the dark scale ratio Select a corresponding scale array in the level comparison table, and replace the input gray scale value with the adjusted gray scale value in the scale array; (4) Select a corresponding scale array from the brightness level comparison table according to the size of the light scale ratio, and The adjusted grayscale value in the proportional array replaces the input grayscale value; and (5) output the adjusted grayscale value to adjust the signal intensity to improve the image quality; thereby adjusting the intensity of the input signal source to obtain better φ image quality . 9. The brightness compensation method for a liquid crystal display as described in item 8 of the scope of the patent application, wherein the dark level ratio refers to the ratio of the number of gray levels in the dark level area to the total number of gray levels, and the range of the dark level area is the total gray level range A range below one scale; the light scale ratio refers to the number of gray scales in the light scale area to the total gray scale Page 21 200525480 6. The ratio of the number of patent applications, and the range of the bright range is more than one percentage of the total gray range. 10. The brightness compensation method for a liquid crystal display as described in item 9 of the scope of the patent application, wherein the range of the dark range is a quarter of the gray range before the total gray range; the range of the bright range is the total gray range. After a quarter of the grayscale range. 1 1. The brightness compensation method for a liquid crystal display as described in item 8 of the scope of patent application, wherein the dark level comparison table is an array composed of a plurality of input gray level values and a complex array proportional array, and each input gray level value can be The scaled array corresponds to an adjusted grayscale value; the light level comparison table is an array of _ plural input grayscale values and a complex array scaled array. Each input grayscale value can be mapped to an adjusted grayscale in the scaled array. Order value. 1 2. The brightness compensation method for a liquid crystal display as described in item 8 of the scope of patent application, wherein the corresponding method of the dark step ratio and the proportional array is to substitute the dark step ratio into a dark step conversion function to obtain a dark step LUT intensity, that is, the dark step LUT intensity = F i (dark scale ratio). This dark scale intensity is mapped to the scale array in the dark scale comparison table, and the gray scale value in the scale array is used instead of the input gray scale value. The light scale φ scale and The corresponding method of the proportional array is to substitute the light-level ratio into a light-level conversion function to obtain a light-level LUT intensity, that is, the light-level LUT intensity = F 2 (light-level ratio), and map this light-level LUT intensity to the light-level comparison table. Scaled array. Use the adjusted grayscale value in this scaled array to replace the input grayscale value. Page 22, 200525480 VI. Patent application range 1 3, as described in the patent application range item 12, brightness compensation method, wherein the dark level and bright level conversion function is an increasing function, that is, the ratio of the dark level and the light level is greater. The higher, the darker and brighter the LUT intensity is, the greater. 14. The brightness compensation method for a liquid crystal display as described in item 8 of the scope of the patent application, wherein the gray scale values between the gray scale values are adjusted to be obtained by interpolation, and a brightness compensation method for a liquid crystal display includes: (1) Measure the original gamma curve of the panel; (2) Set a target gamma curve; Lu (3) Enter an initial grayscale value to get the brightness corresponding to the target gamma curve, and find out the brightness on the original gamma curve Adjusting the grayscale value; (4) repeating the steps (2) to (3) to generate the initial grayscale value of the complex array and the grayscale value of the complex array, and summarize the adjusted grayscale value of the complex array into a proportional array; and ( 5) Repeat the above steps (2) to (4) to generate a complex array proportional array under different target curves to make a comparison table; thereby adjusting the intensity of the input signal source to obtain better φ image quality. 16. A brightness compensation device for a liquid crystal display, comprising: a color scale distribution analysis unit for receiving image signals and counting the number of distributions of each input gray scale value to obtain a color scale distribution state Page 23, 200525480 VI. Patent application scope-a comparison table storage unit to store the comparison table; and a color scale calculation unit to calculate the color scale ratio, which is substituted into the conversion function and converted to the LUT intensity to correspond to the ratio in the comparison table. Array, which replaces the input grayscale value with the adjusted grayscale value in this proportional array and outputs it; thereby adjusting the intensity of the input signal source to obtain better image quality. 17. The brightness compensation device for a liquid crystal display as described in item 16 of the scope of the patent application, wherein the conversion function is an increasing function, that is, the higher the ratio of the dark level and the bright level, the greater the intensity of LU T. 18. The brightness compensation device for a liquid crystal display according to item 16 of the scope of patent application, wherein the grayscale values between the grayscale values are obtained by interpolation. Page 24