CN103050079A

CN103050079A - Method for reducing dynamic false contour of plasma display

Info

Publication number: CN103050079A
Application number: CN2012105720885A
Authority: CN
Inventors: 王付生; 符赞宣; 伍波
Original assignee: Sichuan COC Display Devices Co Ltd
Current assignee: Sichuan COC Display Devices Co Ltd
Priority date: 2012-12-26
Filing date: 2012-12-26
Publication date: 2013-04-17
Anticipated expiration: 2032-12-26
Also published as: CN103050079B

Abstract

The invention discloses a method for reducing a dynamic false contour of a plasma display. The method comprises the following steps of: comparing two adjacent pixels in each line aiming at video data RGB (Red, Green and Blue) from the exterior; and determining a gray level number selection point S between intervals [S noise, S false] according to change slope k of a pixel gray value in set time, wherein S noise indicates the gray level number selection point when the false contour is slight and the noise is serious, and S false indicates the gray level number selection point when the false contour is serious and the noise is slight. The method has the positive effects that different gray level numbers are selectively called by detecting a position having the dynamic false contour according to a detection situation, so that not only the dynamic false contour but also the noise of an image are reduced, and the display effect of a PDP (Plasma Display Panel) is improved.

Description

A kind of method that reduces the plasma display dynamic false contours

Technical field

The present invention relates to a kind of colored three electrode AC plasma display and reduce the image display noise, reduce dynamic false contours, improve the method for image display effect.

Background technology

For PDP, only light or do not light two kinds at the state of keeping each unit of demonstration phase, each discharge was finished in moment, and discharge cell has memory function, can not go to change with the method for modulating pulse width or controlled discharge intensity the brightness of demonstration, realize that namely multi-grey level shows.The intensity of considering each sustain discharge is identical, discharge causes that luminous is exactly a led pulse, so also can utilize in PDP and regulate the method keep pulse number and realize that multi-grey level shows, this also is the basis of the subfield driving method that separates with demonstration of addressing.According to this method, in color PDP, generally the signal quantization with a kind of color is the n bit data, step-by-step shows, the sustain discharge time span of every demonstration phase, and namely led pulse number and this weight are associated, weight is larger, this led pulse number that shows the phase is more, and the brightness that everybody shows is also different, is called a subfield during one the demonstration.To show that data volume turns to 8 as example, a field time is divided into 8 subfields, each subfield comprises preparatory stage, address period and keeps the demonstration phase.Preparatory stage makes full frame all display unit state consistencies, for addressing ready; In address period, each display line of sequential scanning is finished the addressing to full frame all unit; In maintenance phase, demonstration is kept in full frame all unit that accumulated the wall electric charge.The preparatory stage of each subfield, address period time are identical.8 main differences of subfield are time (namely the keeping pulse number) difference of its maintenance phase, for example the corresponding demonstration of 1～8 subfield difference is from the lowest order of view data to most significant digit, then the time of the maintenance phase of 8 subfields becomes the relation of 1:2:4:8:16:32:64:128, and the combination of lighting by different subfields just can realize that 256 grades gray scale shows like this.For example data are 00000000, and then all subfields are not lighted, and are shown as 0 grade of the darkest gray scale; When data are 00001001, only have the first and the 4th subfield to light, the corresponding grey scale level is 9 brightness.Data are 11111111 o'clock, and all subfields are all lighted, and show that image is the brightest, and the corresponding grey scale level is 255 brightness, as shown in Figure 1.

The visual characteristic decider of human eye is when observing moving object, and its viewpoint can move by the accompany movement object together, even can surpass moving object.So during the moving object in observing the PDP picture, for adopting the ADS technology to carry out the PDP that gray scale shows, Jiang Yichang is divided into that a plurality of subfields show.For dynamic menu, because human eye viewpoint accompany movement object is mobile together, its brightness of experiencing is: during the moving point of eye-observation P1, brightness sensation is that P1 on the direction of motion ~ P8 point is respectively in the light pulse sum of SF1 ~ SF8, as shown in Figure 2.Because the luminous unevenness on spatio-temporal distribution of each subfield, for 8 traditional sub-field codes, the dynamic integral distance reaches maximal value when gray level changes between 127 à 128 mutually, namely 127, also just says the dynamic false outline phenomenon of appearance when image gray levels seamlessly transits the most as shown in Figure 3 near 127.We just have the bright fringes appearance when observing image, as shown in Figure 4.

Tradition solves the method for dynamic false contours generally to sacrifice image quality as cost, such as dither algorithm and error diffusion.Traditional coding number (the actual number of greyscale levels that adopts) of generally choosing when taking dither algorithm and error diffusion algorithm is to take into account picture noise and dynamic false contours two aspects, as shown in Figure 5.We can see that gray level along with the actual employing of choosing is more and dynamic false contour is more serious in the drawings, but picture noise will be more and more slighter, sentence and reach balance so generally be selected in the intersection point of dynamic false contours curve and noise curve.Their rudimentary algorithm principle is: be used for showing image (display gray scale) by detecting the order of severity of dynamic false contours, then choose the gray-coded that can suppress dynamic false contours.The pixel grey scale of image is shaken according to selected gray-coded table, and namely the pixel grey scale of image is all shaken contiguous display gray scale, and adopts the mode of error diffusion with the gray level reduction of disappearance.But adopting the method to cause most of display gray scale all is to shake out by several basic gray scales, and picture noise is very large, has reduced the display effect of image.

Summary of the invention

In order to overcome the above-mentioned shortcoming of prior art, the invention provides a kind of method that reduces the plasma display dynamic false contours, realize the reduction of dynamic false contours on the basis that reduces picture noise, improve image displaying quality.

The technical solution adopted for the present invention to solve the technical problems is: a kind of method that reduces the plasma display dynamic false contours, the video data RGB that comes in for the outside, two adjacent pixels in more every row, and according to the variation slope k of grey scale pixel value in setting-up time, at interval [S _{Make an uproar}, S _Pseudo-] between determine the selected point S of gray level number, wherein: S _{Make an uproar}Refer to slight, the gray level number selected point when noise is serious of false contouring; S _Pseudo-Refer to serious, the gray level number selected point when noise is slight of false contouring.

The foundation of determining the selected point S of gray level number is: k is larger, and selected point S is more near S _{Make an uproar}K is less, and selected point S is more near S _Pseudo-

As k during at 0 °～45 °, selected point S is S _Pseudo-As k during at 45 °～90 °, selected point S is S _{Make an uproar}

Compared with prior art, good effect of the present invention is: by the detection to position that dynamic false contours occurs, and the gray level number different according to the detection case Selection and call, not only reduce dynamic false contour but also reduced the noise of image, improve the display effect of PDP.

Description of drawings

Examples of the present invention will be described by way of reference to the accompanying drawings, wherein:

Fig. 1 is ADS type of drive synoptic diagram;

Fig. 2 is subfield brightness accumulation synoptic diagram;

Fig. 3 is the mechanism synoptic diagram that dynamic false contours produces;

Fig. 4 is the dynamic false contour synoptic diagram;

Fig. 5 is the selected point synoptic diagram of traditional gray level number;

Fig. 6 is the selected point synoptic diagram of gray level number of the present invention.

Embodiment

As shown in Figure 6, S _{Make an uproar}Refer to slight, the gray level number selected point when noise is serious of false contouring; S _Pseudo-Refer to serious, the gray level number selected point when noise is slight of false contouring.

A kind of method that reduces the plasma display dynamic false contours comprises the steps:

For the video data RGB that comes in the outside, two adjacent pixels in more every row, and according to the variation slope k of grey scale pixel value in setting-up time, at interval [S _{Make an uproar}, S _Pseudo-] between determine the selected point S of gray level number, wherein: k larger when more serious (be dynamic false contours), selected point S is more near S _{Make an uproar}K less when slighter (be dynamic false contours), selected point S is more near S _Pseudo-

In order to reduce relatively the complicacy of differentiating, when k when 0 °～45 ° (order of severity that is picture noise surpasses dynamic false contours), selected point S is S _Pseudo-When k when 45 °～90 ° (order of severity that is dynamic false contours surpasses picture noise), selected point S is S _{Make an uproar}

Principle of work of the present invention is: in the time of the image motion speed, adjacent pixel changes violent, and just therefore easier generation dynamic false contour adopts less gray level number can reduce largely dynamic false contours; When image freeze or change when slow, be not easy to produce dynamic false contour or dynamic false contour is smaller, therefore adopt more gray level number.By choose different gray level numbers according to the situation of change of image, reach best image effect with this, can realize that the noise of image is slighter, can realize that also dynamic false contour is slighter.

Claims

1. method that reduces the plasma display dynamic false contours is characterized in that: for the video data RGB that comes in the outside, and two adjacent pixels in more every row, and according to the variation slope k of grey scale pixel value in setting-up time, at interval [S _{Make an uproar}, S _Pseudo-] between determine the selected point S of gray level number, wherein: S _{Make an uproar}Refer to slight, the gray level number selected point when noise is serious of false contouring; S _Pseudo-Refer to serious, the gray level number selected point when noise is slight of false contouring.

2. a kind of method that reduces the plasma display dynamic false contours according to claim 1, it is characterized in that: the foundation of determining the selected point S of gray level number is: k is larger, and selected point S is more near S _{Make an uproar}K is less, and selected point S is more near S _Pseudo-

3. a kind of method that reduces the plasma display dynamic false contours according to claim 1 is characterized in that: as k during at 0 °～45 °, selected point S is S _Pseudo-As k during at 45 °～90 °, selected point S is S _{Make an uproar}