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1.
电脑配色系统中的颜色体系相互转换   总被引:6,自引:0,他引:6  
张韬  尚鹤龄 《光学学报》1994,14(1):4-96
本文讨论了适用于电脑配色系统中的各种颜色体系之间的相互转换,并概述了这些转换所需要的数学模型,由于这些数学模型计算简便,因而很容易在计算机上实现。  相似文献   

2.
The theory of the recognized visual space of illumination (RVSI) is that the color appearance of objects in a space is determined in relation to its recognition axis RX whose direction is determined by the brain action to adapt to the illumination in the space. Thus the color constancy holds. RX is applicable to objects in the space but not to an object or a portion that does not belong in the space in terms of illumination, that is to say, the luminance of which is too high based on the illumination for that space. In that case the color appearance would be determined in relation to the fundamental axis FX and the color constancy would not hold. In the present paper the chromaticity points were measured for a test patch that appeared achromatic for various luminance of the patch. The points were close to the color of illumination to indicate the color constancy when the luminance was low enough to assure its appearance as the object color, but they departed from the color of illumination and approached the colorimetrically achromatic color. The color constancy gradually failed for the test patch with the high luminance when the color mode became an unnatural object color and then a light color.  相似文献   

3.
本文介绍了目前在色适应、色貌研究中运用方便而有效一种颜色分度方法──主观评价法。从文献中引述了其基本概念及使用原则,并列举几例说明此方法应用的普遍性和意义。  相似文献   

4.
彩色图像中颜色不变性和耀斑的分离(Ⅰ)   总被引:2,自引:0,他引:2  
黄玉明  徐光佑 《光学学报》1991,11(11):041-1045
景物中物体表面的色品是与该物体形状无关的稳定特性,称为颜色不变性。但是,由于耀斑(highlight)和影绸(shading)的存在,图像中对应物体表面点的色品却是变化的,不具有颜色不变性。正确理解图像颜色的基础是建立颜色反射的物理模型。本文叙述了根据Klinker提出的双色反射模型(the dichromatic reflection model),在三维颜色直方图(3D color histogram)中利用K-L变换做平面拟合,分离面反射分量(interface reflection component)和体反射分量(body reflection component),从而计算光源和物体颜色色度坐标的方法,讨论了实际CCD摄像机的局限性,给出了实验结果。  相似文献   

5.
小范围内精确控制CRT显示颜色和色差的研究   总被引:1,自引:0,他引:1  
目前CRT显示器颜色特性化的最高精度大约是0.5ΔEab。一些在CRT上进行颜色和图像视觉评价的实验要求在颜色中心小范围内能更精确地控制显示颜色和色差。实验中采用了线性插值特性化方法,并提出了一种小范围三通道相互影响的颜色控制方法。实验结果表明:该方法对L,a,b控制的精度分别是0.14,0.082,0.103;对三种色差CIELAB,CIE94和CIEDE2000的控制精度分别是0.18,0.18,0.22。  相似文献   

6.
基于CRT的非对称视觉匹配实验中对立色的显示方法研究   总被引:1,自引:0,他引:1  
对立色是颜色科学研究中的一类特殊颜色现象,通过对其特殊匹配现象的研究,可以揭示人眼彩色视觉信息传递的规律。针对基于CRT的非对称视觉匹配实验的要求,提出了一种色调均匀分布、强度成线性变化的对立色的定义和显示方法,实现了人眼锥体细胞响应LMS与计算机彩色量化值RGB之间的高精度转换和真彩色再现。  相似文献   

7.
Angle coder of anti-counterfeiting color in optical micro-mirror arrays   总被引:1,自引:0,他引:1  
Based on the optical characteristics of optical micro-mirror and subtractive color theory, a new anti-counterfeiting model of micro-mirror pixels was established according to the analysis of the connection between the reflective brightness and structural stability. Our results demonstrate that the digital micro-mirror arrays based on the value of CMYKS subtractive color have enough reflected brightness and stability and can be used for anti-counterfeiting optical variable devices when different printing micro-mirror arrays are coded. The variety of optical effects including a security color switch on or switch off have been demonstrated by the use of different black color K or particular color S value. The display angle or orientation of the security color can be set or coded with the different S or K value.  相似文献   

8.
We investigate the quantum interference of spin wave excitations of a spin-1 atomic Bose condensate confined in an optical lattice. Single-channel and dual-channel interactions are employed in our system, and their induced excitations are compared. Also we consider the interplay of magneto-optical excitations, which leads to a constructive or destructive effect for the creation of magnons based on background excitations. The population distributions of excited magnons can be well controlled by steering the long-range dipole-dipole interactions. Such a scheme can be used to demonstrate conventional quantum-optical phenomena like dynamical Casimir effect at finite temperatures.  相似文献   

9.
This paper presents the experimental optical analysis of the crack inside an electronic component. The optical setup is used to carry out multidimensional deformation measurements using digital color holography and the spatial multiplexing of holograms. Since the Fresnel transform method depends on wavelength, a wavelength-dependent-zero-padding algorithm is described and results in a rigorous sizing of each reconstructed monochrome image. The criterion to optimize the parameters is presented and is based on minimizing the widening of the impulse response of the full recording/reconstruction process. The application of the proposed method is illustrated through the analysis of the mechanical deformation of the electronic component, and offers keys to understand its failure mode in industrial conditions.  相似文献   

10.
For radiation-induced intrinsic color centers, we show that the concentrations of identical centers and the concentration ratios of different centers are quite different in the near-surface layer and within the interior volume of a lithium fluoride crystal. We have established that these differences also depend on the sign of the difference between the temperature at which the crystal was irradiated with γ photons and the vacancy mobility temperature. We provide an interpretation for the results obtained, based on the structural features of the near-surface layer and the concentration ratio of vacancies and electrons in the layer, serving as the starting components for color center formation. We found that the concentrations of centers change over the course of a few days by tens of percent in the layer “emerging” from the interior onto the surface as a result of cleavage of the crystal. We measured the luminescence lifetimes of F3 (R2) and F4 centers: 6.6 nsec and 11.7 nsec. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 775–781, November–December, 2006.  相似文献   

11.
ICF驱动器中光束谐波分离技术   总被引:1,自引:0,他引:1  
在激光惯性约束聚变研究过程中,激光驱动器打靶系统的光束谐波分离技术是驱动器建造研究的重要内容之一。根据高功率固体激光驱动器的发展历程,介绍了几种目前世界上正在应用的光束谐波分离技术,并对这些光束谐波分离方法的优缺点进行了对比分析。结合我国激光驱动器谐波分离技术的发展现状提出了将来的发展方向。这对大型激光驱动器的建造具有一定的指导意义。  相似文献   

12.
多模干涉耦合器一般成像位置分析   总被引:5,自引:4,他引:5  
自映像效应是多模波导的一个重要特性,利用多模波导自映像效应制成的多模干涉耦合器被广泛地应用于集成光学回路中。然而根据以往的文献要得出多模干涉耦合器的成像位置要经过一系列复杂的计算。根据多模干涉耦合器的自映像原理,对多模干涉耦合器的成像位置进行分析。成像位置与输入场位置和位置数密切相关,给出了成像位置的解析表达式,得出奇数、偶数的位置数的成像位置分别对应相同,并且奇、偶数的位置数所对应的成像位置之和为多模波导宽度的成像规律。用导模传输分析法验证了表达式和成像规律的正确性。根据成像位置的表达式和成像规律可以直接得出任意输入场位置和位置数所对应的成像位置。为一维和二维限制的多模干涉耦合器的设计提供了理论基础。  相似文献   

13.
介绍了掺Na的KCl晶体中F_B(Ⅱ)心在液氮温度下的稳定激光运转.Q开关Nd:YAG激光的信频输出泵浦色心晶体.激光发射波长为2.420~2.542μm.对实验结果作了讨论.  相似文献   

14.
Road signs must provide a conspicuous signal to a wide variety of drivers over a broad range of environmental and geometric conditions. Recently, there are an increasing number of applications in which light emitting diodes (LEDs) are used as the light source, including critical transportation signaling. In the presence of fog, the resulting visual signal is disturbed due to light scattering by airborne water droplets. By measuring LED brightness with human spectral sensitivity in various densities and various droplet sizes (10, 30, 50, and 100 μm), it is understood that the particle size distribution (fog droplet size) and density of fog does affect visibility in fog. The colored LEDs that contain a yellow component had high brightness evaluation, blue component had low brightness evaluation in all densities and different droplet sizes. The result in this paper can contribute to air and land traffic safety and the prevention of accidents.  相似文献   

15.
Shuyan He  Liying Song 《Physica A》2010,389(4):825-836
In traffic system, driving behaviors change with the surrounding traffic perceived by drivers, resulting in the complex spatio-temporal traffic patterns. Accordingly, in the majority of traffic models, vehicle accelerations are described by dynamic equations based on driving behavior, system dynamics and some underlying steady-state velocity-gap (bumper-to-bumper spacing) relation in order to guarantee the realistic human behavior. This paper proposes a deterministic car-following model based on a multi-branch fundamental diagram with each branch representing a particular category of driving style. Furthermore, an additional dynamic perception equation is introduced to reflect the driving style adaptation in response to the change in surrounding traffic situations. With simulation based on the proposed “driver perception model” (DP model), empirical findings of traffic breakdown and observed spatio-temporal patterns at on-ramp vicinity are reproduced. Furthermore, comparison results show the consistency between numerical simulation and the real traffic data of Beijing urban freeway.  相似文献   

16.
Anomalies in intertemporal choice (e.g. “hyperbolic” discounting and sign effect) have been investigated in econophysics and behavioral neuroeconomics. We experimentally examined the roles of psychophysical effects of time perception and subjective valuation of outcomes (value function) on temporal discounting of gain and loss, by utilizing a qq-exponential temporal discounting model developed in Tsallis’s thermostatistics. Consequently, we demonstrated that both “hyperbolic” discounting and the sign effect (i.e. gain is more steeply time-discounted than loss) are due to psychophysical effects of time perception (i.e., nonlinearity and gain–loss asymmetry). Implications of the present study for neuroeconomics and econophysics are discussed.  相似文献   

17.
An impression of a surface seen through holes is created when one fuses dichoptic pairs of discs with one member of each pair black and the other white. This is referred to as the ‘sieve effect’. This stimulus contains no positional disparities. The impression of depth in the sieve effect is most evident when the size, contrast, and rim thickness of rivalrous patterns are such as to produce exclusive rivalry. I investigated how long it took for the sieve effect to recover from exclusive rivalry suppression. The magnitude of perceived depth in the effect was measured after exclusive rivalry suppression of one half-image of the sieve-effect stimulus. The results showed that the sieve effect takes approximately 630 ms to recover from exclusive rivalry suppression, compared with 200 ms for disparity-based stereopsis. Considered together with the previous report [Matsumiya and Howard: Invest. Ophthalmol. Visual Sci. 42 (2001) S403] that the sieve effect is positively correlated with the rate of exclusive rivalry, these findings suggest that the effect and exclusive rivalry are processed in the identical channel.  相似文献   

18.
研究了K+对NaCl(OH-)中(F+2)H心的形成及其光谱性质的影响。结果表明,K+的存在抑制了F+2型心的形成,改变了(F+2)H心的光谱性质,拓宽了发射谱的半功率谱宽。从而修正了Polock的实验结果。同时指出,研制具有更宽波长发射范围的Na1-xKxCl(OH-)复合基质F+2型色心激光材料是可能的  相似文献   

19.
20.
To study the vortex behavior in 2D periodic pinning potentials, we measured field dependence of the vortex-flow resistance and the critical current in single-crystal Bi2Sr2CaCu2O8+y (Bi2212) films with an equilateral triangular array of antidots. Fractional matching effect was observed in 1/4, 1/3, 1/2, 2/3, 3/4, and 6/7 of the first matching field H1, and even above H1. While the most of fractional numbers except 1/2 can be explained from commensurability between triangular lattices of antidots and vortices, the matching effect in 1/2H1 suggests the existence of the interstitial vortices in comparison with the results of a reported numerical simulation. The fractional matching effect above H1 can be explained as a matching effect by multi-quanta vortices.  相似文献   

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