CN100481903C

CN100481903C - Adaptive LCD TV display quality adjusting apparatus and method

Info

Publication number: CN100481903C
Application number: CNB2006100618387A
Authority: CN
Inventors: 李海鹰; 沈思宽; 卢铁军; 王鵾; 江�润; 郭明海; 刘志明; 陈狄君
Original assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Current assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Priority date: 2006-07-27
Filing date: 2006-07-27
Publication date: 2009-04-22
Anticipated expiration: 2026-07-27
Also published as: CN1968380A

Abstract

The invention discloses an adaptive adjustment device and method for LCD TV display quality. The adjustment device includes an LCD display module, an information collector capable of collecting parameters related to the ratio of bright areas of an image, and an image enhancement processing module. The collected bright area ratio information is analyzed and processed by the CPU, the signal of the image enhancement processing module is connected to the CPU, the signal of the information collector is connected to the CPU, and the CPU control is connected to the backlight brightness adjustment port of the LCD display module. The present invention automatically determines whether to reduce the brightness of the backlight source of the LCD display module by detecting the ratio of the bright area in the picture; the image enhancement processing module performs brightness correction and black level extension processing of the dark area on the image. It can eliminate the whitening and glare of images caused by too bright images and large areas of bright fields. Therefore, not only the subjective image quality can be improved, the viewer's visual fatigue can be prevented, but also the purpose of energy saving can be achieved.

Description

A kind of self-adaptive regulating of LCD TV display quality and method

Technical field

The present invention relates to the television display technology field, more specifically say the regulation technology that relates to the LCD TV display quality.

Background technology

The LCD TV is being subjected to consumer's favor now, just extensively enters among the ordinary consumer man.But, because LCD is the passive-type display device, come display image by liquid crystal as controlled light valve, simultaneously because the restriction of liquid crystal characteristic, light valve does not reach desirable closed condition, promptly gives complete black signal yet, and the LCD screen also is to have faint light to send, under the lower situation of ambient brightness, the bad phenomenon of black level performance is obvious especially.For specific LCD display module, have only the back light source brightness of reduction could improve the black level performance.Therefore, the LCD TV has the following disadvantages now: 1, under normal family environment for use, particularly under the situation that evening or ambient brightness are lower, brightness is too high, and eyes are tired easily; Part dark in the image can not deceive, and the black level performance is bad, causes the image level sense not strong, and image quality is undesirable.2, the consumed power substantially constant of LCD display, the power consumption of backlight is not regulated according to different situations, generally all is set to maximum power, not only do not meet energy-conservation theory, and too bright meeting backlight causes the problem of display quality.Except above-mentioned two problems, LCD TV exists also that picture is too dazzling, the problem of picture whiting when showing large-area highlighted picture; Make beholder's eyes easily tired (light characteristic of several TVs as shown in Figure 5).This point does not resemble CRT TV and plasm TV, and they have the dynamic brightness regulatory function, makes the mean flow rate of picture milder, thereby improves the comfort level of watching.

The LCD TV that has adopts the rearrangeable switch that the control backlight illumination is set to adjust back light source brightness, and still, this method of adjustment needs not very convenient by manual adjustment, seldom has the consumer to use this adjustment function.

Also disclose two kinds of methods in the invention that we have applied for, first kind of brightness of adopting the checkout gear ambient light and adjusting backlight automatically is to solve surround lighting image whiting when dark, dazzling and problem (shown in Figure 1) that contrast is not enough; Second kind of method that adopts image detection, mainly the dark space ratio of image is carried out sampling analysis, when image details in a play not acted out on stage, but told through dialogues picture is excessive, reduce the brightness of backlight, improve the not enough problem (shown in Figure 2) of the black performance of picture, Fig. 4 is the implementation method flow chart of former detection dark scene.Though these two kinds of methods have solved 1,2 two above-mentioned problem, the picture when not considering picture large tracts of land bright field is highlighted dazzling and spectators' vision caused tired influence.

Summary of the invention

One of technical problem to be solved by this invention provides a kind of self-adaptive regulating of LCD TV display quality, can be highlighted dazzling and spectators' vision caused tired influence by detecting the clear zone ratio in the picture, regulate the LCD TV display quality automatically picture when eliminating picture large tracts of land bright field.

The present invention includes the LCD display module, it is characterized in that: the information acquisition device and the image enhancement processing module that also are provided with an energy images acquired clear zone ratio relevant parameter, an energy carries out the CPU of analyzing and processing to the clear zone percent information that collects, image intensification processing module signal connects CPU, the information acquisition device signal connects CPU, and the back light source brightness of CPU control connection LCD display module is adjusted port.

The all right images acquired dark space of described information acquisition device ratio relevant parameter, described CPU can also carry out analyzing and processing to the dark space percent information that collects.Described image enhancement processing module can dynamically be adjusted the characteristic parameter of each pixel of image.

Two of technical problem to be solved by this invention provides a kind of method that can regulate the LCD TV display quality automatically.

Described method may further comprise the steps:

A, images acquired clear zone ratio relevant parameter;

B, the parameter of collecting is sent to the CPU that presets analysis and processing program, CPU analyzes, if clear zone ratio height, execution in step C if brightness ratio is low, does not then adjust the brightness of backlight;

C, CPU output control information reduces the back light source brightness of LCD display module;

D, image enhancement processing module are extended processing to the black level that image carries out gamma correction and dark space, and the brightness that the dark part in the image becomes is lower.

The parameter that collects in the described steps A can be the parameter of picture signal, as histogram distribution, maximum, minimum value and the mean value etc. of brightness.

Also be provided with the relevant parameter of gathering the dark space ratio and the method for handling by CPU before the described steps A.

The relevant parameter of described collection dark space ratio also be may further comprise the steps by the method that CPU handles: the relevant parameter of described collection dark space ratio also be may further comprise the steps by the method that CPU handles:

(1), images acquired dark space ratio relevant parameter;

(2), the parameter of collecting is sent to the CPU that presets analysis and processing program, CPU analyzes, if dark space ratio height, execution in step C if the darkness ratio is low, does not then adjust the brightness of backlight;

(3), CPU output control information reduces the back light source brightness of LCD display module;

(4) the image enhancement processing module is carried out luminance compensation and white level extension processing to image.

High to the dark space ratio like this image also can utilize the image enhancement processing module that image is carried out luminance compensation and white level extends processing, with the lower image processing step of brightness of the dark part change in the image; The image high to the clear zone ratio also can utilize the image enhancement processing module that the black level that image carries out gamma correction and dark space is extended processing.

Analytic process among the described step B is: CPU handles, estimates the clear zone ratio to the parameter of receiving, and then whether judges the clear zone ratio greater than the threshold values of setting, if greater than, then execution in step C if be not more than, does not then adjust the brightness of backlight.

The control information of CPU output is an information of voltage among the described step C.

The control information of CPU output is PWM (pulse-width modulation) pulse among the described step C.

The present invention comes automatic decision whether to reduce the back light source brightness of LCD display module owing to by detecting the clear zone ratio in the picture, and the image enhancement processing module is handled the black level extension that image carries out gamma correction and dark space simultaneously.The image whiting and the thorn eye problem that can removal of images be brought during too bright and large tracts of land bright field.Therefore, not only subjective image quality can be improved, and prevents beholder's visual fatigue sense, and can reach purpose of energy saving.

Description of drawings

Fig. 1 is ambient light and the composition frame chart of adjusting the brightness regulating apparatus of backlight automatically.

Fig. 2 is the adjusting device composition frame chart of the invention process example.

Fig. 3 is the flow chart of the relevant parameter of CPU analyzing and processing dark space ratio.

Fig. 4 is the flow chart of the relevant parameter of CPU analyzing and processing clear zone ratio.

Fig. 5 is the luminosity response figure of PDP, LCD TV.

Fig. 6 is the peak brightness performance diagram before and after LCD adjusts.

The invention will be further described below in conjunction with the drawings and specific embodiments.

Embodiment

Embodiment 1

Present embodiment comprises the LCD display module, extraction module and Image Enhancement Based piece, CPU.Extraction module can be to the image content features information extraction of picture signal.The information of extracting has the histogram of picture material and mean value etc., then relevant parameter is sent to the CPU that presets analysis and processing program; Then, according to the controlled quentity controlled variable of optimized Algorithm output back light source brightness, different LCD display modules adopts different controlled quentity controlled variables, can be voltage or pwm pulse.

Algorithm is as follows: referring to flow chart, and Fig. 4.At first, extract histogram information, mean value, maximin, the deviate of every two field picture through the image characteristics extraction module to every width of cloth image of input.The ratio Pbr in clear zone in the estimation image, the acquisition of Pbr is meant that brightness is greater than the sum of the pixel of a certain threshold value and the ratio of total pixel number in the image.And then judge that Pbr whether greater than certain threshold value Cbr, such as 70%, less than then not adjusting brightness backlight, makes it to be in maximum; Pbr is greater than Cbr, then calculate and be provided with backlight and reduce parameter Δ R, calculate and be provided with delay parameter Tb, carry out the adjustment control of adaptive backlight source according to Δ R and Tb again, the black level that carries out gamma correction and dark space extends to handle with compensate for backlight brightness and descends and the image quality reduction that causes.For avoiding occurring flicker, in case determine and need regulate, will be at interval with 200-300ms, adjust 1%, 2% or 4% at every turn, from high to low or from low to high, all adopt the mode of approaching gradually to adjust.After adjusting the brightness that makes entire image backlight and descending, carrying out image processing, the dark part in the image will be got off.Gamma correction is according to the ratio of the image of different scenes and backlight adjustment, adjusts the brightness of dark space in proportion, to optimize the contrast of display degree.

Embodiment 2

Adopt and method that the method for the measurement dark space of former invention combines, at first detect the ratio of dark space,, promptly extract histogram information, mean value, maximin, the deviate of every two field picture referring to Fig. 3.Estimate the dark space ratio Pdk under the present status then.And Pdk and the dark space ratio Cdk that presets compared, if, not carrying out backlight less than Cdk, regulates Pdk, carry out common image quality enhancement process; If Pdk is greater than Cdk, calculate and be provided with backlight and reduce parameter Δ R, calculate and be provided with delay parameter Td, carry out the adjustment control of adaptive backlight source according to Δ R and Td again, carry out luminance compensation and white level and extend the image quality reduction that causes with compensate for backlight brightness decline.Otherwise detect the ratio in clear zone, referring to Fig. 4, if the ratio Pbr in clear zone, then presses the brightness that the method for block diagram 4 is adjusted backlight greater than threshold value Cbr; Otherwise keeping the brightness of backlight is 100%.Plant the peak brightness characteristic curve of LCD adjustment front and back as can be seen from Fig. 6.

Claims

1. An adaptive adjustment device for LCD TV display quality, comprising an LCD display module, characterized in that: it is also provided with an information collector that can collect parameters related to the ratio of bright areas of the image and is used to correct the brightness and dark areas of the image. Black level extension processing, an image enhancement processing module that changes the dark part of the image to a lower brightness, and a CPU that can analyze and process the collected bright area ratio information, and the image enhancement processing module signal is connected to the CPU , the information collector signal is connected to the CPU, and the CPU controls the backlight brightness adjustment port connected to the LCD display module; when the information collector collects a high proportion of bright areas, the CPU outputs control information to reduce the brightness of the backlight of the LCD display module, and when the brightness ratio is low , the brightness of the backlight is not adjusted.

2. The adaptive adjustment device according to claim 1, characterized in that: the information collector can also collect parameters related to the proportion of dark areas in the image, and the CPU can also analyze the collected information on the proportion of dark areas deal with.

3. A method for adaptively adjusting the display quality of an LCD TV, comprising the following steps:

A. Acquisition of parameters related to the ratio of the bright area of the image;

B. Send the collected parameters to the CPU with pre-installed analysis and processing program, and the CPU will analyze it. If the ratio of bright areas is high, perform step C. If the ratio of brightness is low, the brightness of the backlight will not be adjusted;

C. The CPU outputs control information to reduce the brightness of the backlight source of the LCD display module;

D. The image enhancement processing module performs brightness correction and black level extension processing of dark areas on the image, so as to make the dark parts of the image even lower in brightness.

4. The adaptive adjustment method according to claim 3, characterized in that: the parameters collected in the step A can be parameters of the image signal, including histogram distribution, maximum value, minimum value, and average value of brightness value.

5. The self-adaptive adjustment method according to claim 3, characterized in that before said step A, there is also a method of collecting relevant parameters of the proportion of dark areas and processing them by the CPU.

6. The self-adaptive adjustment method according to claim 5, characterized in that: the method of collecting the relevant parameters of the dark area ratio and processing them by the CPU comprises the following steps:

(1) Collect parameters related to the ratio of the dark area of the image;

(2), the collected parameters are sent to the CPU preset with the analysis processing program, and the CPU performs analysis, if the dark area ratio is high, step C is performed, if the dark ratio is low, the brightness of the backlight is not adjusted;

(3), the CPU outputs control information to reduce the brightness of the backlight source of the LCD display module;

(4) The image enhancement processing module performs brightness compensation and white level extension processing on the image.

7. The adaptive adjustment method according to claim 3, characterized in that: the analysis process in step B is: the CPU processes the received parameters, estimates the proportion of bright areas, and then judges the proportion of bright areas Whether it is greater than the set threshold, if it is greater, then perform step C, if not, then do not adjust the brightness of the backlight source.

8. The adaptive adjustment method according to claim 3, characterized in that: the control information output by the CPU in the step C is a pulse width modulation pulse.

9. The adaptive adjustment method according to claim 3, characterized in that: the control information output by the CPU in the step C is voltage information.