EP1262941A1 - Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel - Google Patents

Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel Download PDF

Info

Publication number
EP1262941A1
EP1262941A1 EP01113011A EP01113011A EP1262941A1 EP 1262941 A1 EP1262941 A1 EP 1262941A1 EP 01113011 A EP01113011 A EP 01113011A EP 01113011 A EP01113011 A EP 01113011A EP 1262941 A1 EP1262941 A1 EP 1262941A1
Authority
EP
European Patent Office
Prior art keywords
pdp
gray scale
error
adjacent pixels
video signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01113011A
Other languages
English (en)
French (fr)
Inventor
Hsu Liang-Kuei
Lai Yao-Hung
Kao Shiuh-Bin
Chen Kuang-Lang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chunghwa Picture Tubes Ltd
Original Assignee
Chunghwa Picture Tubes Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chunghwa Picture Tubes Ltd filed Critical Chunghwa Picture Tubes Ltd
Priority to EP01113011A priority Critical patent/EP1262941A1/de
Publication of EP1262941A1 publication Critical patent/EP1262941A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007—Display of intermediate tones
    • G09G3/2059—Display of intermediate tones using error diffusion
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007—Display of intermediate tones
    • G09G3/2018—Display of intermediate tones by time modulation using two or more time intervals
    • G09G3/2022—Display of intermediate tones by time modulation using two or more time intervals using sub-frames
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0266—Reduction of sub-frame artefacts
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
    • G09G2320/0276—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007—Display of intermediate tones
    • G09G3/2077—Display of intermediate tones by a combination of two or more gradation control methods
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels

Definitions

  • the present invention relates to PDPs (plasma display panels) and more particularly to a method for implementing error diffusion on PDP so as to solve low level contouring occurred thereon.
  • the relationship of input gray scale versus output brightness of color TV may be plotted as a curve (FIG. 1a).
  • a Gamma ( ⁇ ) compensation process (called compensation process hereinafter) is performed on the original video signal by utilizing above physical characteristic thereof. That is, a compensation process is performed with respect to ⁇ in equation (1).
  • the relationship of input brightness versus output gray scale of color TV may be plotted as a curve (FIG. 1b).
  • ⁇ 0.45 (i.e., obtained from 1/2.2)
  • the video signal received by color TV is converted into image for showing on screen of CRT of color TV.
  • the relationship of input brightness versus output brightness of color TV may be plotted as a straight line (FIG. 1c).
  • a high quality image is shown on the typical color TV without distortion.
  • brightness of respective discharge unit on panel thereof is controlled by discharge number.
  • brightness may be expressed in following equation (2) in terms of discharge number as below (i.e., a straight line):
  • the higher discharge number the brighter of PDP. This is similar to the effect that the larger input voltage the brighter of a typical color TV.
  • the relationship of input brightness versus output gray scale of PDP may be plotted as a curve (FIG. 2a).
  • the relationship of input gray scale versus output brightness of PDP may be plotted as a straight line (FIG. 2b).
  • video signal received by PDP is converted into image for showing on screen of PDP.
  • a distorted image with poor contrast is shown on PDP.
  • an anti compensation process is performed for solving above drawbacks.
  • the relationship of input gray scale versus output gray scale may be plotted as a curve (FIG. 3b).
  • the relationship of input brightness versus output gray scale may be plotted as a curve (FIG. 3a).
  • the relationship of input gray scale versus output brightness of PDP may be plotted as a straight line (FIG. 3c).
  • gray scale of PDP is expressed as a power of 2. For example, in PDP eight bits are needed for representing 256 gray scales.
  • an image is shown on PDP.
  • brightness of PDP is proportional to discharge number thereof. If brightness of one discharge of PDP is equal to N cd/m 2 (N is an integer) N is a minimum brightness of PDP.
  • brightness of PDP may be expressed as a multiple of one discharge of PDP. That is, brightness of PDP is a multiple of N. Hence, brightness of a plurality of k discharges is k 3 ⁇ N (where k 3 is a positive integer). In other words, a brightness of f ⁇ N is not obtainable if f is not an integer (e.g., a brightness of 0.5 ⁇ N).
  • a brightness of PDP can not be expressed by a discharge number having a non-integer value (e.g., decimal).
  • the decimal has to be converted into an integer.
  • This utilizes a cost effective while simple addition circuit in implementing error diffusion for solving the problem of low level contouring in PDP due to insufficient gray scale of video signal in the range of low gray scale.
  • gray scale of the video signal is reduced to 2.30048.
  • decimal fraction of gray scale can not be shown on PDP only gray scale having value two rather than 2.30048 is shown on PDP. That is, there is an error of 0.30048 in gray scale. In view of above, the generation of such error is totally caused by decimal fraction of gray scale which can not be shown on PDP (i.e., only integer gray scale is shown).
  • an error generated by a central pixel on PDP is diffused to adjacent eight pixels in a conventional technique.
  • errors generated by eight adjacent pixels are diffused to (i.e., absorbed by) the central pixel (FIG. 4b). Since each pixel can absorb errors generated by eight adjacent pixels the to be rounded decimal fraction of gray scale may carry forward to become an integer due to the addition of errors of eight adjacent pixels in the process of anti compensation. In other words, such decimal fraction of gray scale is not rounded as expected. Hence, the obtained gray scale is not correct. Further, a practical circuit for implementing error diffusion on PDP is also considered.
  • nine adjacent pixels is simplified to five adjacent pixels (e.g., A, B, C, D, and E in FIGS. 5a and 5b).
  • errors generated by pixels A, B, C and D are diffused to (i.e., absorbed by) the central pixel E.
  • a suitable numeric weighting is multiplied by each pixel having a different location. For example, 1/16, 5/16, 3/16 and 7/16 are multiplied by pixels A, B, C and D respectively (FIG. 6).
  • FIG. 7 a graph shows a relationship of input gray scale versus output gray scale after performing a Gamma anti compensation on video signal.
  • a curve portion in the range of gray scale of 0 to 80 is enlarged in FIG. 8 for further illustrating a relationship of input gray scale versus output gray scale.
  • pixel E may absorb errors generated by adjacent pixels A, B, C and D. Further, a suitable weighting is multiplied by each of pixels A, B, C and D respectively.
  • each of w1, w2, w3, and w4 may be represented by a negative power of integer (e.g., 2) or an addition of a plurality of ones each having a negative power of integer (e.g., 2).
  • each of weightings as represented conventionally by decimal is converted into a negative power of integer 2 or an addition of a plurality of ones each having a negative power of integer 2 by the invention.
  • This utilizes a cost effective while simple addition circuit in implementing error diffusion, resulting in an elimination of error caused by decimal of gray scale as experienced in prior art.
  • a time varying weighting function (e.g., d1(t), d2(t), d3(t), or d4(t)) is multiplied by the associated numeric weighting.
EP01113011A 2001-05-28 2001-05-28 Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel Withdrawn EP1262941A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP01113011A EP1262941A1 (de) 2001-05-28 2001-05-28 Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP01113011A EP1262941A1 (de) 2001-05-28 2001-05-28 Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel

Publications (1)

Publication Number Publication Date
EP1262941A1 true EP1262941A1 (de) 2002-12-04

Family

ID=8177573

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01113011A Withdrawn EP1262941A1 (de) 2001-05-28 2001-05-28 Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel

Country Status (1)

Country Link
EP (1) EP1262941A1 (de)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0893916A2 (de) * 1997-07-24 1999-01-27 Matsushita Electric Industrial Co., Ltd. Bildanzeigevorrichtung und Bildbewertungseinrichtung
EP1020838A1 (de) * 1998-12-25 2000-07-19 Pioneer Corporation Verfahren zur Ansteuerung einer Plasmaanzeigetafel
EP1022714A2 (de) * 1999-01-18 2000-07-26 Pioneer Corporation Verfahren zur Ansteuerung einer Plasmaanzeigetafel

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0893916A2 (de) * 1997-07-24 1999-01-27 Matsushita Electric Industrial Co., Ltd. Bildanzeigevorrichtung und Bildbewertungseinrichtung
EP1020838A1 (de) * 1998-12-25 2000-07-19 Pioneer Corporation Verfahren zur Ansteuerung einer Plasmaanzeigetafel
EP1022714A2 (de) * 1999-01-18 2000-07-26 Pioneer Corporation Verfahren zur Ansteuerung einer Plasmaanzeigetafel

Similar Documents

Publication Publication Date Title
US7006704B2 (en) Method of and apparatus for improving picture quality
US20010033260A1 (en) Liquid crystal display device for displaying video data
US20050163372A1 (en) Video signal processor and method of processing video signal
US20060238655A1 (en) Method and system for automatic color hue and color saturation adjustment of a pixel from a video source
US6137541A (en) Image processing method and image processing apparatus
US7102696B2 (en) Method of effecting various anti compensation processes on segmented gray level of input image on plasma display panel
US6774873B2 (en) Method for implementing error diffusion on plasma display panel
US6774875B2 (en) Method for compensating luminance of a plasma display panel
EP1575264B1 (de) Bildverarbeitungsvorrichtung und -verfahren
US20060114181A1 (en) Multi-gray-scale image display method and apparatus thereof
US5543855A (en) Image processing method and apparatus with error diffusion
EP0554836A2 (de) Vorrichtung zur Erzeugung von parabolischen Wellenformen
US6636229B2 (en) Gradation correction circuit, and γ correction apparatus
US8363168B2 (en) Signal processing apparatus and signal processing method performing gamma correction
US20030156225A1 (en) Gradation correction apparatus
US6020921A (en) Simple gamma correction circuit for multimedia
JP3785922B2 (ja) 表示装置の誤差拡散処理方法
US7088316B2 (en) Color adjustment device and method for plasma display panel
EP1262941A1 (de) Verfahren zur Durchführung von Fehlerdiffusion für eine Plasmaanzeigetafel
EP1258859A1 (de) Verfahren zur segmentierten invertierten Gammakorrektur für eine Plasmaanzeigetafel
KR100669042B1 (ko) 플라즈마 표시판에 관한 에러 확산을 구현하는 방법
JP4379029B2 (ja) 画像処理装置、画像処理方法および画像投射装置
US20100104212A1 (en) Contour correcting device, contour correcting method and video display device
US7154562B1 (en) Methods and circuits for implementing programmable gamma correction
JPH10173958A (ja) 映像信号処理装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20030307

AKX Designation fees paid

Designated state(s): DE FR GB IT NL

17Q First examination report despatched

Effective date: 20071213

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20101201