CN103050079B

CN103050079B - Method for reducing dynamic false contour of plasma display

Info

Publication number: CN103050079B
Application number: CN201210572088.5A
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: 2015-05-27
Anticipated expiration: 2032-12-26
Also published as: CN103050079A

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 reducing plasma display dynamic false contours

Technical field

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

Background technology

For PDP, only light in the state maintaining display phase each unit or do not light two kinds, each electric discharge completes instantaneously, and discharge cell has memory function, can not go by the method for modulating pulse width or controlled discharge intensity the brightness changing display, namely realize multi-grey level display.Consider that the intensity of each sustain discharge is identical, electric discharge causes luminescence to be exactly a LED pulse, regulate the method maintaining pulse number to realize multi-grey level display so also can utilize in PDP, this is also the basis of the sub-field drive method of seeking oil gas.According to this method, in color PDP, general is n-bit data by a kind of signal quantization of color, step-by-step shows, the sustain discharge time span of display phase of every, and namely LED pulse number and this weight are associated, weight is larger, the LED pulse number of this display phase is more, and everybody brightness of display is also different, is called a subfield during the display of.Be quantified as 8 to show data, a field time be divided into 8 subfields, each subfield comprises preparatory stage, address period and maintenance display phase.Preparatory stage makes full frame all display unit state consistencies, for addressing is ready; In address period, order scans each display line, completes the addressing to full frame all unit; In maintenance phase, full frame all unit that have accumulated Wall charge carry out maintenance display.Preparatory stage, the address period time of each subfield are identical.The main difference of 8 subfields is that the time (namely maintaining pulse number) of its maintenance phase is different, such as the corresponding display 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, just can be realized the gray scale display of 256 grades like this by the combination of lighting of different subfield.Such as data are 00000000, then all subfields are not lighted, and are shown as 0 grade of the darkest gray scale; When data are 00001001, only have first and the 4th subfield light, corresponding grey scale level is the brightness of 9.When data are 11111111, all subfields are all lighted, and display image is the brightest, and corresponding grey scale level is the brightness of 255, as shown in Figure 1.

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

Tradition solves the method for dynamic false contours generally to sacrifice image quality for cost, as dither algorithm and error diffusion.Traditional coding number (the actual number of greyscale levels adopted) taking generally to choose when dither algorithm and error diffusion algorithm takes into account picture noise and dynamic false contours two aspect, as shown in Figure 5.We can see that gray level along with the actual employing chosen is more and dynamic false contour is more serious in the drawings, but picture noise will be more and more slighter, so the point of intersection being generally selected in dynamic false contours curve and noise curve is to reach balance.Their rudimentary algorithm principle is: by detecting the order of severity of dynamic false contours, then choosing and the gray-coded of dynamic false contours can be suppressed for showing image (display gray scale).The pixel grey scale of image is shaken according to selected gray-coded table, and namely the pixel grey scale of image all shakes contiguous display gray scale, and adopts the mode of error diffusion by the reduction of the gray level of disappearance.But adopt the method to cause most of display gray scale to be all shake out by several base grey, picture noise is very large, reduces 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 reducing plasma display dynamic false contours, the basis reducing picture noise realizes the reduction of dynamic false contours, improve image displaying quality.

The technical solution adopted for the present invention to solve the technical problems is: a kind of method reducing plasma display dynamic false contours, for the video data RGB come in outside, more often adjacent two pixels in row, and according to the change 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 gray level number selected point when false contouring is slight, noise is serious; S _pseudo-refer to gray level number selected point when false contouring is serious, noise is slight.

Determine that the foundation of the selected point S of gray level number is: k is larger, and selected point S is more close to S _{make an uproar}; K is less, and selected point S is more close to S _pseudo-.

When k is at 0 ° ~ 45 °, selected point S is S _pseudo-; When k is 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 of the position to occurrence dynamics false contouring, and the gray level number different according to detection case Selection and call, both reduce the noise that dynamic false contour again reduces image, improve the display effect of PDP.

Accompanying drawing explanation

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

Fig. 1 is ADS type of drive schematic diagram;

Fig. 2 is its luminance accumulation schematic diagram;

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

Fig. 4 is dynamic false contour schematic diagram;

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

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

Embodiment

As shown in Figure 6, S _{make an uproar}refer to gray level number selected point when false contouring is slight, noise is serious; S _pseudo-refer to gray level number selected point when false contouring is serious, noise is slight.

Reduce a method for plasma display dynamic false contours, comprise the steps:

For the video data RGB come in outside, more often adjacent two pixels in row, and according to the change 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 namely dynamic false contours is more serious), selected point S is more close to S _{make an uproar}; K less (when namely dynamic false contours is slighter), selected point S is more close to S _pseudo-.

In order to reduce the complicacy comparing differentiation, when k is when 0 ° ~ 45 ° (namely the order of severity of picture noise exceedes dynamic false contours), selected point S is S _pseudo-; When k is when 45 ° ~ 90 ° (namely the order of severity of dynamic false contours exceedes picture noise), selected point S is S _{make an uproar}.

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

Claims

1. reduce a method for plasma display dynamic false contours, it is characterized in that: the video data RGB come in for outside, more often adjacent two pixels in row, and according to the change 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 gray level number selected point when false contouring is slight, noise is serious; S _pseudo-refer to gray level number selected point when false contouring is serious, noise is slight; Determine that the foundation of the selected point S of gray level number is: k is larger, and selected point S is more close to S _{make an uproar}; K is less, and selected point S is more close to S _pseudo-.

2. a kind of method reducing plasma display dynamic false contours according to claim 1, is characterized in that: when k is at 0 ° ~ 45 °, selected point S is S _pseudo-; When k is at 45 ° ~ 90 °, selected point S is S _{make an uproar}.