基于视觉匹配的LCD特性化方法研究

【作者】 段剑金；

【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】 随着近年来数字技术、彩色数字图像的不断发展和广泛使用,颜色在不同的设备之间精确地传递或再现成为该领域的重要课题,色彩管理系统(ColorManagement System)的任务就是为了实现这一目的。在颜色管理系统中,最基本的工作就是对输入/输出设备进行特性化。彩色TFT-LCD是一种目前市场上流行的液晶显示器,也是未来显示器的发展方向之一。随着其成本的逐步降低,质量逐步提高,大有取代CRT的趋势。论文以LCD特性化方法为主要研究内容,在广泛查阅国内外文献的基础上,采用基于视觉匹配的设备特性化方法,同时完成了孟塞尔色卡在数码相机和LCD之间的复制。具体完成的研究工作包括:1.通过视觉匹配方法获取CIEXYZ色空间到LCD的RGB空间的训练样本对。将一个给定观察条件下的一些色貌因素“映射”到另一媒体上。2.用视觉匹配结合BP神经网络方法建立LCD的XYZ(?)RGB的非线性映射关系。选取的训练样本数量较少,得出了数码相机特性化平均△E~*ab为4.2761;最大△E~*ab为11.1962;最小△E~*ab为0.9713。LCD特性化平均△E~*ab为4.2711;最大△E~*ab为12.1545;最小△E~*ab为0.4108。这个色差属于可接受范围,可以满足多数实际应用的要求。本文的研究成果不仅对彩色数字输入输出设备技术有理论价值,而且在印刷、医疗诊断、化妆品生产、各种照明条件下不同媒体颜色再现等领域有应用前景。更多还原

【Abstract】 With the development and wide application of color imaging during recent years,the communication and reproduction of color information among different devices is becoming an important subject and is the task of Color Management System(CMS).In the CMS,the main works is to character the input/output devices.The color TFT-LCD is a kind of popular LCDs in present market,and is a development orientation of the future LCDs.It tends to replace CRT owing to the decreasing cost and increasing quality.This thesis concentrates on the characterization of LCD.After reading a lot of references,we provide a method of device characterization based on visionmatching and accomplish the reproduction of Munsell Color Chips between still digital camera and LCD.The corresponding research work include the following aspects:1.After studying the properties of the present characterization methods.We obtain the training sample couple—CIEXYZ color space and RGB space of LCD via "visualmatching" method,and mapped some color appearance factors to another media under the certain observational conditions.2.we built the nolinear mapping relation between XYZ and RGB of LCD,carried out LCD characterization by virtue of the Back-Propagation(BP) artificial neutral network and "Visualmatching".Andwe chose and studied a few samples:the mean of digital camera’s characterization,ΔE~*ab,is 4.2761;the maximalΔE~*ab is 11.1962;the minimalΔE~*ab is 0.9713;the mean of LCD’s characterization,ΔE~*ab,is 4.2711;the maximalΔE~*ab is 12.1545;the minimalΔE~*ab is 0.4108.These color differences are acceptable and can satisfy most of actual application requirements.The research results in this paper have not only some theoretical importance, but have good application foreground in such fields as print,medical diagnoses, cosmetic production and the reproduction of different media colors under various lighting conditions about the face color.更多还原