阅读说明：本技术 一种动态调节背光的方法 (Method for dynamically adjusting backlight ) 是由 李薇 于 2020-12-16 设计创作，主要内容包括：本发明涉及电视领域,公开了一种动态调节背光的方法,利用直方图数据,动态降低背光,达到能效指标要求并优化画质同时满足在节能状态下测试需要的目的。本发明首先获取电视当前显示画面的直方图数据信息；之后判断直方图数据属于何种信号类型,若属于特定静态测试信号,则将背光值设置为最大值MAX；若属于非特定静态测试信号,则进一步判断出直方图数据对应是暗场景还是亮场景,当判断为暗场景,将背光值Duty设置为最大值MAX；当判断为亮场景,将背光值Duty设置为Middle；其中Middle为电视在出厂前根据能效等级要求所调试出的正常背光值,该正常背光值小于电视的最大背光值。本发明适用于电视背光调节。(The invention relates to the field of televisions and discloses a method for dynamically adjusting backlight, which utilizes histogram data to dynamically reduce backlight so as to achieve the aims of meeting the energy efficiency index requirement and optimizing image quality and meeting the test requirement in an energy-saving state. Firstly, acquiring histogram data information of a current display picture of a television; then, judging the signal type of the histogram data, and if the histogram data belongs to a specific static test signal, setting the backlight value as a maximum value MAX; if the histogram data belong to the unspecific static test signal, further judging whether the histogram data correspond to a dark scene or a bright scene, and if the histogram data correspond to the dark scene, setting the backlight value Duty to be a maximum value MAX; when the scene is judged to be bright, setting the backlight value Duty to Middle; wherein, Middle is a normal backlight value debugged according to the energy efficiency grade requirement before the television leaves the factory, and the normal backlight value is smaller than the maximum backlight value of the television. The invention is suitable for television backlight adjustment.)

1. A method for dynamically adjusting a backlight, comprising the steps of:

A. acquiring histogram data information of a current display picture of a television;

B. judging the signal type of the histogram data, and if the histogram data belongs to a specific static test signal, setting the backlight value Duty as a maximum value MAX;

if the histogram data belong to the unspecific static test signal, further judging whether the histogram data correspond to a dark scene or a bright scene, and setting the backlight value Duty as a maximum value MAX when the histogram data correspond to the dark scene or the bright scene; when the scene is judged to be bright, setting the backlight value Duty to Middle; wherein, Middle is a normal backlight value debugged according to the energy efficiency grade requirement before the television leaves the factory, and the normal backlight value is smaller than the maximum backlight value MAX of the television.

2. The method of claim 1, wherein the specific method of step a comprises: the 32-bit histogram data of the current display picture is obtained from the television core and recorded as L (n), wherein n is 0, 1, … and 31.

3. The method of claim 2, wherein the specific static test signals comprise red field, green field, and full white field signals.

4. The method as claimed in claim 3, wherein the full white field is determined by: the ratio PLWhite of the non-all white level bits L (0) -L (28) in the histogram data is calculated by the following formula,

if PLwhite is 0, determining that the signal is a full white field signal;

the judgment mode of the red field is as follows: the duty ratio PLRed of the red level L (6) in the histogram data is calculated by the following formula,

if PLRed is 100, judging as a red field signal;

the green field is judged in the following way: the occupancy ratio PLGreen of the green level positions L (21) -L (22) in the histogram data is calculated by the following formula,

if PLGreen is 100, then the field is determined to be green.

5. The method of claim 2, wherein the non-specific static test signals comprise a blue field, color bars, an energy efficiency test squared grid, and dynamic signals; the step B of judging whether the histogram data corresponds to a dark scene or a bright scene comprises the following specific steps:

defining the position of the dark level in the 32-bit histogram data, and calculating the occupation ratio PLBright of the dark level bit in the 32-bit histogram data;

judging the relation between the PLBright and a preset threshold, and judging the scene as a dark scene when the PLBright is greater than the preset threshold; and when the PLBright is smaller than the threshold value, judging the scene is bright.

6. The method of claim 5, wherein L (0) -L (4) in the 32-bit histogram data are defined as dark levels, and the calculation formula of PLBright is as follows:

7. the method as claimed in claim 2, wherein the step B further determines whether the histogram data belongs to a full black field signal, and sets the backlight value to 0 if the histogram data belongs to the full black field signal.

8. The method as claimed in claim 7, wherein the determination of the full black field is as follows: the share PLBlack of the non-all black level bits L (2) -L (31) in the 32-bit histogram data is calculated by the following formula,

if PLBlack is less than or equal to 2, the field is judged to be a full black field.

Technical Field

The invention relates to the field of televisions, in particular to a method for dynamically adjusting backlight.

Background

The national energy efficiency index test allows the television to have a dynamic backlight function, and the dynamic power is tested under the dynamic backlight function, so that the energy efficiency index is improved. In order to reduce power consumption, the dynamic backlight function needs to reduce the backlight brightness, and the backlight brightness changes with the signal content in terms of image quality. Therefore, the dynamic backlight function should reduce the backlight and ensure the image quality after the backlight reduction.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for dynamically adjusting the backlight utilizes the histogram data to dynamically reduce the backlight, and achieves the purposes of meeting the energy efficiency index requirement and optimizing the image quality and meeting the test requirement in the energy-saving state.

In order to solve the problems, the invention adopts the technical scheme that: a method of dynamically adjusting a backlight, comprising the steps of:

A. acquiring histogram data information of a current display picture of a television;

B. judging the signal type of the histogram data, and if the histogram data belongs to a specific static test signal, setting the backlight value Duty as a maximum value MAX;

if the histogram data belong to the unspecific static test signal, further judging whether the histogram data correspond to a dark scene or a bright scene, and setting the backlight value Duty to be a maximum value MAX when the histogram data correspond to the dark scene or the bright scene; when the scene is judged to be bright, setting the backlight value Duty to Middle; wherein, Middle is a normal backlight value debugged according to the energy efficiency grade requirement before the television leaves the factory, and the normal backlight value is smaller than the maximum backlight value MAX of the television.

Further, the specific method of step a comprises: the 32-bit histogram data of the current display picture is obtained from the television core and recorded as L (n), wherein n is 0, 1, … and 31.

Generally, the static test signals may generally include red field, green field, blue field, full white field signals, blue field, color bars, energy efficiency test squared signals, and the like; when the test requirements are met, the histogram data of the energy efficiency test nine-square grid signal and the blue field conform to the dark scene of the dynamic scene, and the histogram data of the color bar signal conforms to the bright scene of the dynamic scene, so that the blue field, the color bar and the energy efficiency test nine-square grid signal do not need to be independently judged and processed as a specific static test signal, and the specific static test signal only comprises a red field signal, a green field signal and a full white field signal;

further, the determination method of the full white field may be: the ratio PLWhite of the non-all white level bits L (0) -L (28) in the histogram data is calculated by the following formula,

if PLwhite is 0, determining that the signal is a full white field signal;

the red field can be judged by the following steps: the duty ratio PLRed of the red level L (6) in the histogram data is calculated by the following formula,

if PLRed is 100, judging as a red field signal;

the green field can be judged by the following method: the occupancy ratio PLGreen of the green level positions L (21) -L (22) in the histogram data is calculated by the following formula,

if PLGreen is 100, then the field is determined to be green.

Further, the non-specific static test signal specifically comprises a blue field, a color bar, an energy efficiency test squared figure and a dynamic signal; the step B of determining whether the histogram data corresponds to a dark scene or a bright scene may include:

defining the position of the dark level in the 32-bit histogram data, and calculating the occupation ratio PLBright of the dark level bit in the 32-bit histogram data;

judging the relation between the PLBright and a preset threshold, and judging the scene as a dark scene when the PLBright is greater than the preset threshold; and when the PLBright is smaller than the threshold value, judging the scene is bright.

Further, according to the practical verification of the inventor, it is generally defined that L (0) -L (4) in the 32-bit histogram data are dark levels, and the calculation formula of PLBright is as follows:

further, step B needs to further determine whether the histogram data belongs to a full black field signal, and if the histogram data belongs to the full black field signal, to avoid light leakage of the television, the backlight value may be set to 0. The determination method of the full black field may be: the share PLBlack of the non-all black level bits L (2) -L (31) in the 32-bit histogram data is calculated by the following formula,

if PLBlack is less than or equal to 2, the field is judged to be a full black field.

The invention has the following beneficial effects: the image quality effect of the invention is designed to be a negative effect, namely, a scene signal is lightened, and the backlight is reduced, so that firstly, the energy consumption can be reduced, and secondly, the picture is soft and not dazzling; and the dark scene signal and the backlight are fully turned on, so that the power consumption is not reduced, and the expressive force of dark field details is ensured. In addition, in special scenes such as a full white field, a red field, a green field, a blue field, a color bar, an energy efficiency test Sudoku signal and the like, the backlight is set to be in a required state for testing requirements; the light leakage protection is to turn off the backlight completely in the case of a completely black scene to prevent light leakage in the picture. Therefore, under the condition of reducing backlight, the invention considers various scene requirements, ensures the image quality effect, ensures that bright signals are not dazzling, improves the expressive force of dark field details, has soft and comfortable pictures, achieves the aims of energy saving and testing, and is suitable for long-time watching at home of a user.

Drawings

FIG. 1 is a flow chart of the algorithm of the present invention;

fig. 2 is a diagram of histogram data for a television core.

Fig. 3 is a schematic diagram of active signal backlight control.

Detailed Description

The image quality effect of the invention is designed to be a negative effect, namely, a scene signal is lightened, and the backlight is reduced, so that firstly, the energy consumption can be reduced, and secondly, the picture is soft and not dazzling; and the dark scene signal and the backlight are fully turned on, so that the power consumption is not reduced, and the expressive force of dark field details is ensured. In addition, in special scenes such as a full white field, a red field, a green field and the like, the backlight is set to be fully on for testing requirements; setting blue field, squared figure and color bar signals along with the dynamic scene; the light leakage protection is to turn off the backlight completely in the case of a completely black scene to prevent light leakage in the picture. The specific scheme of the invention is as follows:

firstly, histogram data information of a current display picture of the television is acquired, here, 32-bit histogram data of the current display picture can be acquired from a television core, and recorded as l (n), wherein n is 0, 1, …, 31, and a pattern of the histogram data is shown in fig. 2.

Then, judging the signal type of the histogram data, if the signal type is a specific static test signal, such as a red field, a green field or a full white field, setting the backlight value to be a maximum value MAX; if the test signal is an unspecific static test signal, such as a blue field, a Sudoku, a color bar signal or a dynamic signal, further judging whether the histogram data corresponds to a dark scene or a bright scene, and when the histogram data is judged to be the dark scene, setting the backlight value Duty to be a maximum value MAX; when the scene is judged to be bright, setting the backlight value Duty to Middle; wherein, Middle is a normal backlight value debugged according to the energy efficiency grade requirement before the television leaves the factory, and the normal backlight value is smaller than the maximum backlight value MAX of the television. In addition, in order to realize light leakage protection, when the histogram data is judged to belong to a full black signal, the backlight value is set to be 0.

Specifically, the specific steps of determining whether the histogram data corresponds to a dark scene or a bright scene in the present invention include:

defining the position of the dark level in the 32-bit histogram data, and calculating the occupation ratio PLBright of the dark level data in the 32-bit histogram data;

judging the relation between the PLBright and a preset threshold, when the PLBright is larger than the preset threshold, judging the scene as a dark scene, and then setting the backlight value Duty as a maximum value MAX; when PLBright is less than the threshold, it is judged as a dark scene, and then the backlight value Duty is set to Middle.

The present invention is further illustrated by the following examples.

The embodiment provides a method for dynamically adjusting backlight, which comprises three parts, namely backlight control of an active signal, wherein the backlight brightness changes along with the change of the signal content; detecting and controlling special scenes such as a Sudoku test signal for energy efficiency calibration, a monochromatic field signal for color gamut test and a full white field signal for maximum brightness test; and thirdly, black scene light leakage protection. As shown in fig. 1, the specific implementation steps are as follows:

firstly, acquiring histogram data information of a current display picture of a television, wherein 32-bit histogram data of the current display picture can be acquired from a television core and recorded as L (n), wherein n is 0, 1, …, 31;

then, respectively calculating the ratio of the red level, the green level, the full white level, the full black level and the definition dark level according to the histogram data;

then, according to the calculated level bit ratio, judging which signal type the histogram data belongs to, and performing backlight control, special scene detection control or black scene light leakage protection control of the active signal:

1. active signal backlight control

1) First, the position of the dark level is defined in the 32-bit histogram data, and the data of the lower 5 bits of L (0), L (1), L (2), L (3), and L (4) can be defined as the dark level in the present algorithm.

2) According to the characteristics of the moving signal picture and the requirement of picture quality effect, pictures with different characteristics are selected, histogram data of the pictures are analyzed, and scenes of bright and dark demarcation points are selected.

3) The ratio of the scene dark level data in the entire Pixel TOTAL (0-31 bit histogram data) is calculated as a judgment threshold for the bright and dark scene of the active signal.

4) Calculating the ratio PLBright of the total dark level data in the 32-bit histogram data, and calculating the formula as follows:

5) judging PLBright, when the PLBright is larger than a preset threshold (60 is taken as an example), judging the scene as a dark scene, and setting the backlight value Duty as a maximum value MAX; when the PLBright is smaller than the threshold value, judging as a bright scene, and setting the backlight value Duty to Middle; wherein, Middle is a normal backlight value debugged according to the energy efficiency grade requirement before the television leaves the factory, and the normal backlight value is smaller than the maximum backlight value MAX of the television. The active signal backlight control principle is shown in fig. 3.

The threshold may be adjusted when a certain scene requires setting the backlight to MAX or to Middle.

When the energy efficiency test meets the fluctuation rate requirement, the value of Middle can be adjusted. In the present algorithm, when the fluctuation ratio is 25%, Middle is 63, and when the fluctuation ratio is 27%, Middle is 60.

2. Special scene detection

The television performs some detection tests under the condition that the dynamic backlight energy-saving function is turned on.

1) The television tests the maximum brightness and with a full white field signal, the backlight needs to be set to MAX.

The judgment mode of the full white field is as follows: the ratio PLWhite of the non-all white level bits L (0) -L (28) in the 32-bit histogram data is calculated by the following formula,

and if the PLwhite is 0, determining that the field is a full white field.

2) The television set tests the color gamut using monochromatic field (red, green, blue, etc.) signals, and the backlight value needs to be set to the maximum value MAX.

The judgment mode of the red field is as follows: the duty ratio PLRed of the red level bit L (6) in the 32-bit histogram data is calculated by the following formula,

if PLRed is 100, then the field is determined to be red.

The green field is judged in the following way: the occupation ratio PLGreen of the green level bits L (21) -L (22) in the 32-bit histogram data is calculated by the following formula,

if PLGreen is 100, then the field is determined to be green.

Since the histogram data of the blue field corresponds to the dark scene of the dynamic scene, the backlight can be automatically set to MAX in the active signal backlight control mode, and thus, a separate judgment process is not required here.

3) In the energy efficiency calibration of the television, when the calibration requirement is met, the Sudoku test signal of the energy efficiency calibration conforms to the dark scene of a dynamic scene, so the backlight value can be automatically set to MAX according to the active signal backlight control mode.

4) The rated power test of the television usually adopts the color bar signal to carry on the rated power test of the television, because when meeting the test requirement of the rated power, the histogram data of the color bar signal accords with the bright scene of the dynamic scene, so can set up the backlight value to Middle automatically according to the control mode of the backlight of the active signal.

3. Black scene light leak protection

The judgment method of the full black field is as follows: the share PLBlack of the non-all-black level bits L (2) -L (31) in the 32-bit histogram data is calculated by the following formula,

if PLBlack is less than or equal to 2, the field is judged to be a full black field, and in order to realize light leakage protection, the full black field needs to set the backlight value to 0.

Through the dynamic backlight algorithm processing, the embodiment can present a dynamic image quality effect, so that bright signals are not dazzling, the expressive force of dark signals is enhanced, the image is soft and comfortable, and the aim of saving energy is fulfilled.