液晶显示器特性化方法研究
摘要
数字图像设备的精确特性化是色彩管理的基础。彩色显示设备作为计算机重要的输出设备,对其显色的精确性要求较高,因此高效、精确的特性化方法研究愈显重要。在过去的十几年里,国内外对传统的CRT显示器的特性化研究逐渐成熟,其在颜色科学与工程领域得到了广泛的应用。近几年,LCD以其轻量、低功耗、环保、显示信息量大等优点逐渐取代CRT显示器,成为主流显示设备。为使颜色信息在复制传递过程中达到“所见即所得”,对LCD的颜色特性进行深入研究,并以ICC标准对其进行精确特性化是非常必要的。
本文在研究LCD的呈色原理及显色特点的基础上,利用实验对LCD的时间稳定性、通道独立性、色品恒常性等物理性能进行了深入的研究和分析。实验结果表明,该LCD在开机2.5小时以后基本达到稳定,图像稳定时间为5秒。通道独立性差,通道之间干扰较为严重。色品恒定性测试显示,即使是经黑点校正之后,色品也发生变化。空间均匀性在中间调和亮调部分较差。这些实验结果,与国内外学者归纳总结的LCD显色特点相符。
对GOG模型、S-CurveⅡ模型、TPC模型和PP模型四种LCD特性化方法进行了对比实验。通过实验测量出样本的CIE XYZ三刺激值。选择合适的样本作为各模型的训练样本,拟合得到各模型;模型的评价采用CIELAB色差公式和CIEDE2000色差公式,分别计算了各模型的512个检验样本的色差,得到平均色差、最小、最大色差,并比较了各模型的色差精度。另外又研究了检验色差随明度、彩度和色相角的分布情况。实验结果表明,PP模型平均色差达到了2.8135△E_(ab)~*和1.2660△E_(00),是四个模型中精度最高的,TPC模型的平均色差只比PP模型略大,精度较高。PP模型和TPC模型可以用于颜色复制要求较高的场合。GOG模型和S-CurveⅡ模型的平均色差都较大,只能满足一般的颜色复制要求。
The accurate colorimetric characterization of the digital image devices is the basis in the color management. As an important output equipment of the computer, the color displays need high color accuracy, so exploring efficient and accurate characterization has become more important. In the past ten years, the methods of the CRT colorimetric characterization have been developed maturely and used in the field of color science and engineering. In recent years the LCD is gradually replacing CRT for its light weight, low power consumption, environmental protection and large information. In order to achieve 'WYSIWYG' in color reproduction, studying the color characteristics and accurate colorimetric characterization of LCD is necessary.
Based on the study of the color characteristics of LCD, we study the physical properties of LCD, such as time stability, channel independence, chromaticity constancy and so on. The experimental results show that the LCD reachs stable basically after 2.5 hours of warm up time and the image need five seconds to reach stable. There are crosstalk inter-channels and the primary chromaticity is varying. These experimental results are the same as the scholars summarized.
In this paper, the GOG model, S-CurveⅡmodel, TPC model and PP model were studied on the same LCD. Appropriate measurements are selected as training sample and the models are fitted. The evaluation of the models is using CIELAB color difference and CIEDE2000 color difference. The color differences of the 512 testing samples are calculated. The color accuracy of the four models is compared according to the average, smallest and greatest color differences. In addition the color differences distribution with the brightness, chroma and hue angle are also compared. The experimental results show that the PP model has the highest accuracy with 2.8135ΔE~*_(ab) and 1.2660ΔE_(00·) The mean color difference of The TPC model is a little larger than the PP model, so the PP model and TPC model can be used in the higher requisition color reproduction. The mean color differences of the GOG model and S-CurveⅡare a little larger. These two models can satisfy the general needs.
本文在研究LCD的呈色原理及显色特点的基础上,利用实验对LCD的时间稳定性、通道独立性、色品恒常性等物理性能进行了深入的研究和分析。实验结果表明,该LCD在开机2.5小时以后基本达到稳定,图像稳定时间为5秒。通道独立性差,通道之间干扰较为严重。色品恒定性测试显示,即使是经黑点校正之后,色品也发生变化。空间均匀性在中间调和亮调部分较差。这些实验结果,与国内外学者归纳总结的LCD显色特点相符。
对GOG模型、S-CurveⅡ模型、TPC模型和PP模型四种LCD特性化方法进行了对比实验。通过实验测量出样本的CIE XYZ三刺激值。选择合适的样本作为各模型的训练样本,拟合得到各模型;模型的评价采用CIELAB色差公式和CIEDE2000色差公式,分别计算了各模型的512个检验样本的色差,得到平均色差、最小、最大色差,并比较了各模型的色差精度。另外又研究了检验色差随明度、彩度和色相角的分布情况。实验结果表明,PP模型平均色差达到了2.8135△E_(ab)~*和1.2660△E_(00),是四个模型中精度最高的,TPC模型的平均色差只比PP模型略大,精度较高。PP模型和TPC模型可以用于颜色复制要求较高的场合。GOG模型和S-CurveⅡ模型的平均色差都较大,只能满足一般的颜色复制要求。
The accurate colorimetric characterization of the digital image devices is the basis in the color management. As an important output equipment of the computer, the color displays need high color accuracy, so exploring efficient and accurate characterization has become more important. In the past ten years, the methods of the CRT colorimetric characterization have been developed maturely and used in the field of color science and engineering. In recent years the LCD is gradually replacing CRT for its light weight, low power consumption, environmental protection and large information. In order to achieve 'WYSIWYG' in color reproduction, studying the color characteristics and accurate colorimetric characterization of LCD is necessary.
Based on the study of the color characteristics of LCD, we study the physical properties of LCD, such as time stability, channel independence, chromaticity constancy and so on. The experimental results show that the LCD reachs stable basically after 2.5 hours of warm up time and the image need five seconds to reach stable. There are crosstalk inter-channels and the primary chromaticity is varying. These experimental results are the same as the scholars summarized.
In this paper, the GOG model, S-CurveⅡmodel, TPC model and PP model were studied on the same LCD. Appropriate measurements are selected as training sample and the models are fitted. The evaluation of the models is using CIELAB color difference and CIEDE2000 color difference. The color differences of the 512 testing samples are calculated. The color accuracy of the four models is compared according to the average, smallest and greatest color differences. In addition the color differences distribution with the brightness, chroma and hue angle are also compared. The experimental results show that the PP model has the highest accuracy with 2.8135ΔE~*_(ab) and 1.2660ΔE_(00·) The mean color difference of The TPC model is a little larger than the PP model, so the PP model and TPC model can be used in the higher requisition color reproduction. The mean color differences of the GOG model and S-CurveⅡare a little larger. These two models can satisfy the general needs.
引文
[1]ICC Profile Format Specification Version 3.2.International Color Consortium,Nov.1995.
[2]Lindsay W MacDonald.Developments in colour management systems[J].Displays,1996,16(4):204-211.
[3]W.T.Wintringham.Color television and colorimetry[C],Proc.IRE,1951,39:1135-1173.
[4]F.J.Bingley.Colorimetry in color television[C],Proc.IRE,1953,41:838.
[5]Cowan,W.B.An inexpensive scheme for calibration of a color monitor in terms of standard CIE coordinates[J].Computer Graphics,1983,17:315.
[6]MacLeod,D.I.A,Computer controlled color display in vision research:possibilities and problems[J].Color Research and Application,1986,11:45.
[7]Hartmann,W.T and Madden,T.E.Prediction of display colorimetry from digital video signals[J].Journal of Imaging Technology,1987,13(4):103-108.
[8]Post,D.L.,An evaluation of methods for producing desired colors on CRT[J].Color Research and Application,1989,14:172.
[9]Lucassen M P,Walraven J.Evaluation of a simple method for color monitor recalibration[J].Color Res.App.1990,15(5):321-326.
[10]Po-Chieh Hung,Colorimetric calibration in electronic imaging devices using a look-up-table model and interpolations[J].Journal of Electronic Imaging,1993,2(1):53.
[11]Berns,R.S.,CRT colorimetry part Ⅰ:theory and practice[J].Color Research and Application,1993,18:299.
[12]Roy S Berns,CRT colorimetry part Ⅱ:metrology[J].Color Research and Application,1993,18(3):15.
[13]Roy S Berns,Methods for characterizing CRT displays[J].Displays 1996,16(4):173.
[14]P.A.Rhodes and M.R.Luo,A system for WYSIWYG colour communication[J].Displays,1992,16(4):213.
[15]Tony Johnson.Methods for Characterizing Colour Scanners and Digital Cameras[J].Displays,1996,16(4):183-191.
[16]王敬平.计算机控制的CRT真彩色显示技术的研究[D].北京理工大学博士论文,1994
[17]廖宁放.基于神经网络的CRT色度变换方法[D].北京理工大学博士论文,1999,1:2-8
[18]Mark D.Fairchild,David R.Wybe.Colorimetric Characterization of Apple Studio Display(Flat Panel LCD).Munsell Color Science Laboratory Technical Report,1998.
[19]Young Kwak and Lindsay.Accurate Prediction of Colours on Liquid Crystal Displays[C].IS&T/SID Ninth Color Imaging Conference.2001:355-359.
[20]Nobuhiko Tamura,Norimichi Tsumura and Yoichi Miyake.Masking Model for Accurate Colorimetric Characterization of LCD[C].IS&T/SID Tenth Color Imaging Conference,2002:312-316.
[21]Ellen A.Day.Colorimetric characterization of a Computer-Controlled[SGI]CRT Display.Munsell Color Science Laboratory Technical Report,2002.
[22]Senfar Wen,Royce Wu.Two-Primary Crosstalk Model for Characterizing Liquid Crystal Displays[J].Color research and application,2006,2(31):102-108.
[23]张显斗,徐海松.液晶显示器颜色特征化的分段分空间模型[J].光学学报,2007,27(9):1719-1724.
[24]王勇,徐海松.液晶显示器颜色特征化的S模型算法[J].中国图像图形学报,2007,12(3):491-494
[25]荆其诚等.色度学[M].北京:科学出版社,1979.
[26]汤顺清.色度学[M].北京:北京理工大学出版社,1993,23.
[27]赵秀萍.CIELAB色空间及应用[J].印刷标准化,2003.5,11-13.
[28]ROY S.BERNS.颜色技术原理[M].北京:化学工业出版社,2002:85-95.
[29]周瑞.彩色数码相机色彩空间转换模型的研究[D].西安理工大学硕士学位论文,2007,9.
[30]黄国祥.RGB颜色空间及其应用研究[D].中南大学博士学位论文,2002.9.
[31]朱海侠.计算机输入输出设备色彩管理系统的研究[D].西安理工大学硕士学位论文,2007.3.
[32]徐敏,徐锦林,周世生.CMS中关于CIE1931 RGB与CRTRGB的探讨[J].印刷世界,2002.1:4-6.
[33]徐海松.颜色信息工程[M].杭州:浙江大学出版社,2005:88-90
[34]刘浩学.CIE均匀颜色空间与色差公式的应用[J].北京印刷学院学报,2003,11(3):1-4.
[35]Dong-Ho Kim,Eun Kyoung Cho,Jae Pil Kim.Evaluation of CIELAB-based Colour-Difference Formulae Using a New Dataset[J].Color research and application,2001,26(5):369-375.
[36]郑元林,杨淑蕙等.CIE1976LAB色差公式的均匀性研究[J].包装工程,2005,26(2):48-65.
[37]Luo M R,Rigg B,Chromaticity-discrimination ellipses for surface colours Color research and application,1986,11:25-42.
[38]M.R.Luo,G.Cui,B.Rigg.The Development of the CIE 2000 Colour-Difference Formula:CIEDE2000[J].Color research and application,2001,5:340-350.
[39]郑元林,刘士伟.最新色差公式:CIEDE2000[J].印刷标准化,2004,7:34-37[32].
[40]宦晖,李为.用查找表搜索匹配方法标定CRT[J].光学技术,2000.1,26(1):35-36.
[41]LIAO N,GAO Z.A comparative study of a CRT colorimetric prediction model by neural networks and the models by conventional method[J].Color Res.Appl.,1999,24(1):45-51.
[42]LIMAN D,LIAO N.Overtraining in back-propagation neural networks:a CRT color calibration example[J].Color Res.Appl.,2002,27(2):122-125.
[43]Yasuhiro Yoshida and Yoichi Yamamoto.Proposal for Color Management of LCD[C].IS&T/SID Ninth Color Imaging Conference.233-238.
[44]Yasuhiro Yoshida and Yoichi Yamamoto.Color Calibration of LCDS[C].IS&T/SID Tenth Color Imaging Conference.305-311.
[45]周艳琼,白木.液晶显示技术综述[J].影像技术,2002.4:10-15.
[46]白木,子荫.液晶显示器技术全揭示.有线电视技术全揭示,2002,16:73-78.
[47]徐良波.TFT-LCD滤色器用三色感光剂研究[D].江南大学硕士学位论文,2008:1-3.
[48]陆丽丽.对于小尺寸TFT-LCM gamma校正的研究[D].电子科技大学硕士学位论文,2007:5-7.
[49]徐宇博.TFT-LCD画面品质改善的研究与分析[D].天津大学硕士学位论文,2006:2-18
[50]李宏彦,杨久霞,吕艳英等.TFT-LCD用彩色滤光片[J].现代显示,2005,52:42-44.
[51]Gabrel Marcu,Wei Chen and Kok Chen et al.Color characterization issues for TFT LCD display[C].Proc.SPIE 4663:187-198.
[52]G.Marcu.Tutorial on Color on Electronic Display[C].IS&T/SID Ninth Color Imaing Conferenc,2001,345-354.
[53]Sharma Gaurav.Comparative Evaluation of Color Characterization and Gamut of LCD versus CRTs[C].Proc.SPIE,2001,4663:177-186.
[54]王勇.数字图像设备颜色特征化及其再现理论与技术研究[D].浙江大学博士学位论文,2006:77.
[2]Lindsay W MacDonald.Developments in colour management systems[J].Displays,1996,16(4):204-211.
[3]W.T.Wintringham.Color television and colorimetry[C],Proc.IRE,1951,39:1135-1173.
[4]F.J.Bingley.Colorimetry in color television[C],Proc.IRE,1953,41:838.
[5]Cowan,W.B.An inexpensive scheme for calibration of a color monitor in terms of standard CIE coordinates[J].Computer Graphics,1983,17:315.
[6]MacLeod,D.I.A,Computer controlled color display in vision research:possibilities and problems[J].Color Research and Application,1986,11:45.
[7]Hartmann,W.T and Madden,T.E.Prediction of display colorimetry from digital video signals[J].Journal of Imaging Technology,1987,13(4):103-108.
[8]Post,D.L.,An evaluation of methods for producing desired colors on CRT[J].Color Research and Application,1989,14:172.
[9]Lucassen M P,Walraven J.Evaluation of a simple method for color monitor recalibration[J].Color Res.App.1990,15(5):321-326.
[10]Po-Chieh Hung,Colorimetric calibration in electronic imaging devices using a look-up-table model and interpolations[J].Journal of Electronic Imaging,1993,2(1):53.
[11]Berns,R.S.,CRT colorimetry part Ⅰ:theory and practice[J].Color Research and Application,1993,18:299.
[12]Roy S Berns,CRT colorimetry part Ⅱ:metrology[J].Color Research and Application,1993,18(3):15.
[13]Roy S Berns,Methods for characterizing CRT displays[J].Displays 1996,16(4):173.
[14]P.A.Rhodes and M.R.Luo,A system for WYSIWYG colour communication[J].Displays,1992,16(4):213.
[15]Tony Johnson.Methods for Characterizing Colour Scanners and Digital Cameras[J].Displays,1996,16(4):183-191.
[16]王敬平.计算机控制的CRT真彩色显示技术的研究[D].北京理工大学博士论文,1994
[17]廖宁放.基于神经网络的CRT色度变换方法[D].北京理工大学博士论文,1999,1:2-8
[18]Mark D.Fairchild,David R.Wybe.Colorimetric Characterization of Apple Studio Display(Flat Panel LCD).Munsell Color Science Laboratory Technical Report,1998.
[19]Young Kwak and Lindsay.Accurate Prediction of Colours on Liquid Crystal Displays[C].IS&T/SID Ninth Color Imaging Conference.2001:355-359.
[20]Nobuhiko Tamura,Norimichi Tsumura and Yoichi Miyake.Masking Model for Accurate Colorimetric Characterization of LCD[C].IS&T/SID Tenth Color Imaging Conference,2002:312-316.
[21]Ellen A.Day.Colorimetric characterization of a Computer-Controlled[SGI]CRT Display.Munsell Color Science Laboratory Technical Report,2002.
[22]Senfar Wen,Royce Wu.Two-Primary Crosstalk Model for Characterizing Liquid Crystal Displays[J].Color research and application,2006,2(31):102-108.
[23]张显斗,徐海松.液晶显示器颜色特征化的分段分空间模型[J].光学学报,2007,27(9):1719-1724.
[24]王勇,徐海松.液晶显示器颜色特征化的S模型算法[J].中国图像图形学报,2007,12(3):491-494
[25]荆其诚等.色度学[M].北京:科学出版社,1979.
[26]汤顺清.色度学[M].北京:北京理工大学出版社,1993,23.
[27]赵秀萍.CIELAB色空间及应用[J].印刷标准化,2003.5,11-13.
[28]ROY S.BERNS.颜色技术原理[M].北京:化学工业出版社,2002:85-95.
[29]周瑞.彩色数码相机色彩空间转换模型的研究[D].西安理工大学硕士学位论文,2007,9.
[30]黄国祥.RGB颜色空间及其应用研究[D].中南大学博士学位论文,2002.9.
[31]朱海侠.计算机输入输出设备色彩管理系统的研究[D].西安理工大学硕士学位论文,2007.3.
[32]徐敏,徐锦林,周世生.CMS中关于CIE1931 RGB与CRTRGB的探讨[J].印刷世界,2002.1:4-6.
[33]徐海松.颜色信息工程[M].杭州:浙江大学出版社,2005:88-90
[34]刘浩学.CIE均匀颜色空间与色差公式的应用[J].北京印刷学院学报,2003,11(3):1-4.
[35]Dong-Ho Kim,Eun Kyoung Cho,Jae Pil Kim.Evaluation of CIELAB-based Colour-Difference Formulae Using a New Dataset[J].Color research and application,2001,26(5):369-375.
[36]郑元林,杨淑蕙等.CIE1976LAB色差公式的均匀性研究[J].包装工程,2005,26(2):48-65.
[37]Luo M R,Rigg B,Chromaticity-discrimination ellipses for surface colours Color research and application,1986,11:25-42.
[38]M.R.Luo,G.Cui,B.Rigg.The Development of the CIE 2000 Colour-Difference Formula:CIEDE2000[J].Color research and application,2001,5:340-350.
[39]郑元林,刘士伟.最新色差公式:CIEDE2000[J].印刷标准化,2004,7:34-37[32].
[40]宦晖,李为.用查找表搜索匹配方法标定CRT[J].光学技术,2000.1,26(1):35-36.
[41]LIAO N,GAO Z.A comparative study of a CRT colorimetric prediction model by neural networks and the models by conventional method[J].Color Res.Appl.,1999,24(1):45-51.
[42]LIMAN D,LIAO N.Overtraining in back-propagation neural networks:a CRT color calibration example[J].Color Res.Appl.,2002,27(2):122-125.
[43]Yasuhiro Yoshida and Yoichi Yamamoto.Proposal for Color Management of LCD[C].IS&T/SID Ninth Color Imaging Conference.233-238.
[44]Yasuhiro Yoshida and Yoichi Yamamoto.Color Calibration of LCDS[C].IS&T/SID Tenth Color Imaging Conference.305-311.
[45]周艳琼,白木.液晶显示技术综述[J].影像技术,2002.4:10-15.
[46]白木,子荫.液晶显示器技术全揭示.有线电视技术全揭示,2002,16:73-78.
[47]徐良波.TFT-LCD滤色器用三色感光剂研究[D].江南大学硕士学位论文,2008:1-3.
[48]陆丽丽.对于小尺寸TFT-LCM gamma校正的研究[D].电子科技大学硕士学位论文,2007:5-7.
[49]徐宇博.TFT-LCD画面品质改善的研究与分析[D].天津大学硕士学位论文,2006:2-18
[50]李宏彦,杨久霞,吕艳英等.TFT-LCD用彩色滤光片[J].现代显示,2005,52:42-44.
[51]Gabrel Marcu,Wei Chen and Kok Chen et al.Color characterization issues for TFT LCD display[C].Proc.SPIE 4663:187-198.
[52]G.Marcu.Tutorial on Color on Electronic Display[C].IS&T/SID Ninth Color Imaing Conferenc,2001,345-354.
[53]Sharma Gaurav.Comparative Evaluation of Color Characterization and Gamut of LCD versus CRTs[C].Proc.SPIE,2001,4663:177-186.
[54]王勇.数字图像设备颜色特征化及其再现理论与技术研究[D].浙江大学博士学位论文,2006:77.