液晶显示器特性化方法研究

【作者】 孙娅妮；

【导师】 杨卫平；

【作者基本信息】 云南师范大学 ， 光学工程， 2009， 硕士

【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△E₀₀,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。更多还原

【Abstract】 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.更多还原