计算机CRT的色彩管理研究

按照国际颜色协会ICC制定的开放式色彩管理标准,文章采用BP网络算法模型,建立了CRT的设备特征描述Profile文件,实现了基于ICC标准的CRT色彩管理。     

基于ICC标准的色彩管理研究

色彩管理已成为操作系统的一个重要组成部分,它为各种设备和平台提供一致的、高质量的色彩再生机制.当前,ICC标准已被很多软、硬件厂商所接受,并成为事实上的色彩管理工业标准.实现基于ICC标准的色彩管理系统虽然可采用不同的技术和方法,但是,这些技术和方法不能对所有应用提供一个完备的解决,因而给系统集成带来很大困难.该文综述了基于ICC标准的色彩管理技术,内容涉及色彩管理的基本概念、色彩管理系统的不同实现策略、存在的问题以及今后的研究方向.     

基于小波神经网络的显示器色彩管理模型

CRT显示器的色彩管理是彩色图像复制的关键技术之一.在分析呈色原理的基础上,提出了一种新的CRT显示器色彩管理模型.首先采用标准色靶作为实验样本,并以彩色梯尺区色块代表整个色空间用以推导模型以解决实验色块选取难的问题;其次介绍了实验数据采集方法,并建立若干数据库用以推导模型;随后推导和分析了基于小波神经网络的显示器色彩管理模型,并提出了一些提高模型收敛速度的改进措施.最后实验结果表明,该模型能够提高CRT显示器的色彩管理精度,工程实际中能够用于CRT显示器的色彩管理.     

ICC色彩管理技术

介绍了颜色管理系统出现的背景、ICC的发展历史、颜色管理中几种色彩模型以及ICC色彩管理系统,并在此基础上给出了色彩设备ICC Profile文件的生成过程.     

CRT显示图像的色彩管理新模型

目的 目前色彩管理模型或是注重呈色原理分析,或是仅控制模型的输入输出两端,导致色彩转换精度不高。鉴于此在分析呈色原理的基础上,提出一种CRT显示图像色彩管理新模型。方法 采用标准色靶作为实验样本,结合显示器的呈色原理,以色靶的彩色梯尺区色块代表整个色空间用以推导模型,解决了显示器色彩校正中样本色块选择的难题;随后,重新解释尤尔—尼尔森方程的参数,使原本只适用于印刷网点图像的呈色模型也适用于非印刷网点图像;其次,结合尤尔—尼尔森方程和显示器呈色原理,利用修正后的缩张拟合算法分单色、双色和3色逐步修正和补偿色彩误差,推导出CRT显示器的色彩管理新模型。结果 本模型能够提高CRT显示器的色彩管理精度54%以上,能够用于工程实际中的CRT显示器色彩管理。结论 借助于其他图像设备的呈色原理,本文模型不仅能提高色彩转换精度,也具备较好的参考借鉴价值。     

图像色偏的量化研究与应用

目前，国内外针对各种色彩I／O设备中图像色偏的量化的研究还比较薄弱，虽然有ICC色彩标准，但是没有一个独立于设备的图像色偏量化标准。本文试图提出一套独立于打机、印刷机等色彩设备的色偏量化体系与方法，通过该方法的应用可方便地实现不同种类的数码打样(印刷机打样，照排机打样，屏幕打样等)。随着色偏量化的深入研究与应用，业界通过主观经验进行色彩纠偏的做法将会成为历史。     

DeviceLink技术在PhotoShop中的应用

ICC色彩特性文件(ICC Profile)是用来描述输入、输出设备或者某种色彩空间颜色特性的数据集合,它被广泛用于色彩管理。通常情况下,用设备特性文件在色彩管理中实施颜色转换的时候,要经过连接空间(PCS)进行转换,即先把源颜色空间的颜色转化到PCS空间,再由PCS空间转换到目标颜色空间。连接空间一般是与设备无关的颜色空间,例如CIEXYZ或CIELAB。这种方法在颜色空间转换过程中,会对部分颜色重新进行分色,有可能丢失一些非常重要的颜色信息。而DeviceLink技术与传统的基于ICC的色彩转换不同,能够直接在设备颜色空间之间建立联系。下面我们将探讨DeviceLink Profile的工作原理以及应用。     

LG1730P液晶显示器

在用户评论CRT与LCD的优缺点时，总会说到一个问题，就是CRT的色彩还原比LCD更真实，这的确是LCD天然的缺点，但经过厂家不断的内部优化，一些LCD显示器同样也能表现出相当不错的色彩。     

17英寸LCD显示器 BenQ FP71E＋／FP785

过去的一段时间里，液晶显示逐步开始取代传统CRT显示器的地位，位由于液晶本身的特性限制，与CRT显示器相比，色彩饱和度较低，色彩范围较窄，受到了不少用户的抱怨，为了改变这种状况，各液晶显示器生产厂商一直在液晶面板方面进行改进，     

用好ICC,再现色彩的本来面目

ICC是国际色彩联盟(International Color Consortium)的缩写。国际色彩联盟的官方网址为http://www.color.org/index.xalter。作为一个由企业联合发起的组织,国际色彩联盟成立于1993年。当时计算机图形图像技术正在起步,但是由于不同企业、不同设备之间制造的显示、输出设备的色彩差异明显,于是Adobe、爱克发、苹果公司、柯达、微软、硅谷图形公司、升阳、Taligent等八家公司联合成立了ICC组织,旨在通过联盟,得到一个通用的色彩管理办法,使得色彩不会因为不同的操作系统、软件而有所不同。     

用多隐层BP网实现的CRT色度变换

为了实现彩色信息的标准化显示,需要对ＣＲＴ的色度空间进行标定,也就是ＣＲＴ的Ｒ、Ｇ、Ｂ空间与ＣＩＥ的标准色度空间的相互转换问题,人工神经网络近年来被广泛应用于多种颜色空间的变换过程中,在分析前人经验的基础上,提出了一种采脾四隐层ＢＰ网的ＣＲＴ的Ｒ、Ｇ、Ｂ与ＣＩＥ的Ｘ、Ｙ、Ｚ色度空间的变换方法,实验结果表明,该方法的收敛性和训练时间均优于前人采用２个或３个隐层的方案,而且通过对５１２个训练样本的实验     

基于CRT的无损高效门限彩色图像秘密共享信息隐藏算法

目前对秘密图像共享的研究主要集中在灰度图像上, 而日常生活中使用的图像大多是彩色的, 因此, 研究彩色图像的秘密共享具有重要的意义和应用价值. 该方案将基于中国剩余定理(CRT)的秘密共享与DCT信息隐藏技术进行结合, 保障了传输彩色秘密图像的安全性. 在生成端, 利用DCT信息隐藏算法将彩色秘密图像通过CRT生成的彩色秘密影子图像, 嵌入至用户提供的彩色载体图像中, 并分发. 在恢复端提取出影子图像, 使用CRT恢复彩色秘密图像. 该过程满足(t, n)门限. 实验结果验证, 该算法可实现无损恢复, 并用相关参数对该方案进行评估, 优于其他方案.     

Beam landing adjustment for color purity of integrated tube component using artificial neural network

High speed process that producing high quality picture in adjusting color CRT (Cathode Ray Tube) is desired in industrial process of CRT monitor or television.

The process of adjusting for improving the quality of picture on color CRT performed by adjust the components of ITC (Integrated Tube Component). Beam landing adjustment performing is to localized center of deflection of three electron beam precisely hitting phosphor points. As part of industrial process, its done automatically. To achieve the purpose as desired, we attempt to use supervised learning neural network algorithm for adjustment process.     

用点阵打印机打印彩色图形

本文主要论述了点阵打印机打印彩色田形和彩色显示器存贮图形的原理，并举例说明打印机打印彩色图形的具体实现过程．     

Color computer graphics in magnetic field analysis by means of the finite element method

The finite element method for electromagnetic fields is very popular because of its powerful numerical techniques. Since the output from the finite element analyses (F.E.A.) usually makes a pile of numerical data, it is very important to display them intelligibly and accurately in order to assist analysts in understanding and evaluating the results. Three post-processing methods in the F.E.A. using a multi-color pen plotter or a color CRT are proposed: (1) Depiction of magnetic flux lines in two or three dimensional fields by using a multi-color pen plotter, (2) Depiction of magnetic flux density distribution with flux lines in two dimensional fields by using a color CRT, (3) Depiction of error distribution by using a color CRT.

By using these three methods analysts can visually grasp the behavior of the magnetic fields and the error distribution in detail.     

The impact of color combinations on the legibility of text presented on LCDs

The paper investigates the impact of text and background color combinations on the legibility of text presented on LCDs. The legibility of 56 elementary color combinations was tested by 308 participants. The first task required the participants to identify 21 uppercase alphabetic characters selected and presented in conformance with a Snellen chart in various color combinations. For each color combination, the number of correctly identified characters was recorded as a visual performance measure. In the second task, participants subjectively rated the legibility of color combinations on a ten-point Likert scale. The results show that neither the Le Courier legibility table nor the CRT legibility table is appropriate for LCDs. A new legibility table is proposed for LCDs where the highest ranked are contrastive color combinations with positive polarity whereas for CRT displays, the highest ranked are contrastive color combinations with negative polarity. The findings of this study can be used to determine the best possible color combinations when developing content displayed on LCDs.     

Masking model for accurate colorimetric characterization of LCD

Abstract— A color management system (CMS) such as ICC profile or sRGB space have been proposed for color transformation and reproduction of cross media. In such a CMS, accurate colorimetric characterization of a display device plays a critical role in achieving device‐independent color reproduction. In the case of a CRT, colorimetric characterization based on a GOG model is accurate enough for this purpose. However, there is no effective counterpart in liquid‐crystal displays (LCDs) since the characterization of an LCD has many difficulties, such as channel interaction and non‐constancy of channel chromaticity. In this paper, a new method of display characterization is proposed which is applicable to the assessment of color reproduction of LCDs. The proposed method characterizes an electro‐optical transfer function considering both channel interaction and non‐constancy of channel chromaticity. Experimental results show that the proposed method is very effective in the colorimetry of LCDs.     

A CAD System for Color Design of a Car

We have developed a color CAD system which enables a color designer to evaluate and create body colors of a car on a graphic display and put this system into practical use. The system has three features; generating realistic images comparable to photography to satisfy the car designer's needs, through close analysis of the physical phenomena taking place in the real environment, reproducing the desired colors very accurately on a CRT monitor, through analysis of the CRT colorimetric characteristics of reproducing the specified colors in response to the input signals, and utilizing a parallel computer to generate realistic images at a high speed and to control colors through interactive operation. Application of the CAD system reported here to the field of color design made it possible to fully evaluate and create body colors by means of computer graphics, replacing the conventional method which requires the painting of clay models or prototype cars.