CN100362547C

CN100362547C - Image quality improving method for color plasma display screen

Info

Publication number: CN100362547C
Application number: CNB2005100961847A
Authority: CN
Inventors: 郭应锋; 刘洋; 王付生; 徐曼
Original assignee: SICHUAN STEROPE ORION DISPLAY CO Ltd
Current assignee: Sichuan Sterope Orion Display Co., Ltd.
Priority date: 2005-10-14
Filing date: 2005-10-14
Publication date: 2008-01-16
Anticipated expiration: 2025-10-14
Also published as: CN1770235A

Abstract

The present invention provides a method for improving the image quality of a color plasma display screen, which makes the MPD value between adjacent display units of a moving image minimum through searching approximate codes of luminous modes with different gray scales. Besides, the present invention is combined with an error diffusion method to make a table be possibly identical with the luminous modes of the adjacent display units. Thereby, the present invention reduces the phenomenon of a false contour and improves the image quality of the color plasma display screen.

Description

A kind of image quality improving method of color plasma display

Technical field

The present invention relates to a kind of improvement method of picture quality, particularly a kind of image quality improving method of color plasma display.

Background technology

Color plasma display is to keep making alive on electrode X, Y and the addressing electrode A, utilizing electrode surface discharge, and excitated fluorescent powder is luminous realizes what image showed.Its gray scale shows the employing sub-field technology of addressing display separation (ADS technology), is about to eight son fields of a branch, and each son field is divided into reset period, address period again and keeps the phase.

The false contouring phenomenon is because a kind of visual scalloping that the integrating effect of human eye and employing ADS technology combine and produce.Proposed at present the whole bag of tricks and reduced the influence that dynamic false contours shows image, controlled method, cut apart authority baryon field method, adjust a son DISPLAY ORDER method, compensated pulse method, error-diffusion method etc. as adaption brightness.But there is following defective in said method: adaption brightness control method mainly is that the mean flow rate of some of statistics is adjusted sub-number of fields order, and sub-number of fields remains fixing for each.Though this method can weaken false contouring to a certain extent, has reduced the brightness of image.Cutting apart authority baryon field method mainly is that the son field that weight is big is cut apart, and sub-number of fields order is greater than Ba Zichang, and at present the highest can accomplish 14 son fields.This method and adaption brightness control method are similar, are that sub-number of fields order is fixed, and also are the brightness that has reduced image.Adjusting a son DISPLAY ORDER method is that the order of son field is upset, and this method can only be to reduce the phenomenon that occurs false contouring under the part occasion easily, but can cause other occasions false contouring can occur again.The compensated pulse method is to weaken the false contouring phenomenon by the increase of the parton field being kept umber of pulse, but distortion can appear in the local image.Error-diffusion method is many a kind of methods of using at present, and this method mainly is that calculated amount is bigger, and the storage space that needs is very big, needs the expansion external memory storage, has increased cost.

Summary of the invention

The objective of the invention is to overcome the shortcoming of above-mentioned prior art, provide a kind of by seeking the close coding of different gray shade scale light-emitting modes, make that the MPD value between the adjoining display unit of mobile image is minimum, and carry out the establishment of form in conjunction with error-diffusion method, make that the light-emitting mode of adjacent display cell is identical as far as possible, thereby reduced the image quality improving method of the color plasma display of false contouring.

For achieving the above object, the technical solution used in the present invention is:

For every kind of coding of each gray shade scale, at first according to d _Mpd=| P _i-P _j| * SP ^T-| i-j| calculates the MPD value of this coding and other all codings, wherein: d _MpdBe MPD value P _i, P _jBe that gray shade scale is the coding of i, j, SP ^TBe the transposition of weight vectors, i, j are gray shade scales; Secondly, pick out the minimum coding of MPD value in every kind of gray shade scale, as the corresponding look-up table of this coding.Same principle can be made each self-corresponding look-up table in this manner to 2048 kinds of codings.If the MPD value that all codings of certain coding of certain gray shade scale and another or several gray shade scales calculate is all greater than threshold values D, the value of general threshold values D can not be greater than 64, rule of thumb determine, be to determine the tangible critical value of false contouring phenomenon, then can choose the content of the coding of contiguous gray shade scale as look-up table, MPD mean value minimum between all codings of this coding and other gray scales, gray scale difference value between the two be multiply by coefficient of diffusion 7/16 respectively, 3/16,5/16,1/16, the result calculated right side that is added to, the lower-left, down, on the display unit of bottom right, promptly be with the difference of the gray scale of current actual output and the gray scale that should export calculate through MPD and the error diffusion processing after, again gray scale difference value is returned as feedback quantity and next grey input of measuring addition as look-up table.Display unit for next line, calculate the time of addition, promptly count at the laggard row of horizontal synchronizing pulse, if resolution is m * n with a counter, when P of delegation point adopted error-diffusion method, then the one's own profession counting during for P+1 with feedback quantity and the addition of next input gray level value; For the display unit of next line, counting down to P-1, P carries out the feedback quantity addition during P+1.

The present invention combines by dynamic coding method and error-diffusion method, finds the light-emitting mode two kinds of identical codings of trying one's best, thereby makes the false contouring of moving image weaken.

Description of drawings

Fig. 1 is that coding of the present invention is chosen process flow diagram.

Fig. 2 is d _MpdThe process flow diagram that value is calculated and minimum value is chosen.

Fig. 3 passes through d _MpdValue is selected back p _IjCorresponding form.

Fig. 4 is the error diffusion schematic diagram.

Embodiment

Below in conjunction with drawings and Examples content of the present invention is done and to be specified.

With reference to Fig. 1, method of the present invention is, for every kind of coding p of each gray shade scale _Ij, at first according to d _Mpd=| P _i-P _j| * SP ^T-| i-j| calculates all coding p of this coding and other _kThe MPD value, wherein: d _MpdBe the MPD value, P _i, P _jBe that gray shade scale is the coding of i, j, SP ^TBe the transposition of weight vectors, i, j are gray shade scales.Secondly, judge all d _MpdWhether value is greater than given threshold values D, if d _MpdGreater than threshold values D, then choose and close on gray-coded, if d _MpdThen choose d less than threshold values D _MpdMinimum value d _{Min (mpd)}Corresponding codes is at last with selected coding output.

Among Fig. 1, p _IjThe gray shade scale of exporting for a last display unit is the j kind coding of i, p _kFor current gray shade scale through error diffusion processing back input is all codings of k, wherein p _k=p _{M+ ∑ Δ}, m is actual input gray level grade, the ∑ Δ is the gamma error sum that is diffused into current display unit.

With reference to Fig. 2, present embodiment has 256 gray shade scales, for each coding of each gray shade scale, makes d with other all codings of gray shade scale _MpdValue is calculated, and this coding and gray shade scale are that all codings of m are made d _MpdEach d after the calculating _MpdValue compares, with minimum d _MpdValue d _{Min (mpd)}As feedback quantity, choosing gray shade scale is the minimum therewith d of all codings of m _MpdThat coding that value is corresponding is as the content in the look-up table.

With reference to Fig. 3, for for gray shade scale being j the coding p of i _IjCarry out d with all codings of other gray shade scales _MpdValue is calculated, and finds out minimum d in every kind of gray shade scale _MpdValue d _{Min (mpd)}Corresponding codes is as the content in the corresponding form.Coding wherein is select after calculating through value.

With reference to Fig. 4, be that the coding of n and the coding of contiguous gray shade scale are made d in gray shade scale _MpdAfter value is calculated, d _MpdAverage is all greater than threshold values D, and then this coding can not be as the content of look-up table.Need make error diffusion and handle, promptly be to choose the content of a coding as look-up table in contiguous gray scale m grade, and this coding must can satisfy d _MpdAverage is less than threshold values D.Then with the gray scale difference value Δ between gray scale n and the gray scale m according to 7: 3: 5: 1 ratio to the right, the lower-left, down and the bottom right display unit spread, on the gray-scale value of these several display units that are added to.The gray-scale value m that Δ is wherein represented actual displayed with should gray-scale displayed value n poor.

Claims

1. the image quality improving method of a color plasma display is characterized in that, for every kind of coding p of each gray shade scale _Ij, p _IjThe expression gray shade scale is j the coding of i, at first according to d _Mpd=| P _i-P _j| * SP ^T-| i-j| calculates all coding p of this coding and other _kD _MpdValue, wherein: d _MpdBe the MPD value, P _i, P _jBe that gray shade scale is the coding of i, j, SP ^TBe the transposition of weight vectors, i, j are gray shade scales, secondly, judge all d _MpdWhether value is greater than given threshold values D, if d _MpdGreater than threshold values D, then choose the content of the coding of the gray shade scale of being close to, if d as look-up table with gray shade scale i _MpdLess than threshold values D, then choose d _MpdMinimum value d _{Min (mpd)}Corresponding codes is as the content of look-up table, at last with selected coding output.

2. method according to claim 1, it is characterized in that, the described coding of choosing contiguous gray shade scale is meant as the content of look-up table, MPD mean value minimum between all codings of this coding and other gray scales, with gray shade scale is that gray scale difference value between i and the gray shade scale adjacent thereto multiply by coefficient of diffusion 7/16 respectively, 3/16,5/16,1/16, the result calculated right side that is added to, the lower-left, down, on the display unit of bottom right, promptly be that the gray scale of current actual output is being passed through d with the difference of the gray scale that should export _MpdAfter calculating and error diffusion are handled, again gray scale difference value is returned as feedback quantity, with the input of next ash tolerance addition as look-up table, display unit for next line, calculate the display unit of next line and the time point of feedback quantity addition, promptly count at the laggard row of horizontal synchronizing pulse, if resolution is m * n with a counter, when P of delegation point adopted error-diffusion method, then the one's own profession counting during for P+1 with feedback quantity and the addition of next input gray level value; For the display unit of next line, counting down to P-1, P carries out the feedback quantity addition during P+1.

3. method according to claim 1 is characterized in that the value of threshold values D is smaller or equal to 64.