平面内一组线段相对于实光源的可见性

给定平面内一组互不相交的线段，本文讨论其相对于实光源的可见性，分析了实光源的三种表现形态，发现其中的点光源和平行光滑是光源的两种特殊情况，得到了在实光源的照射下，寻找可见边的算法，并证明其算法的复杂度不大于O(m ln m)，同时给出了一个实测。     

更上一层楼新一代商用投影机及激光光源投影机评测专题

激光光源会一统江湖吗？ 激光光源的出现绝对是投影行业的一个里程碑。目前来看，激光光源的优势相当明显，只是技术还并没有我们想像的那般成熟。激光光源的出现，会如何改变投影业界的格局呢？又会在何时取代传统光源呢？     

基于谐波检测技术的光纤甲烷气体传感器的研究

基于甲烷气体的近红外吸收光谱，研究了一种高灵敏度光谱吸收型光纤甲烷气体传感器。采用DFBLD作为光源，通过光源调制实现气体浓度的谐波检测，利用二次谐波与一次谐波的比值来消除由光源的不稳定和变化所引起的检测误差。建立了谐波检测的数学模型，给出了甲烷气体的测量结果。     

美丽是如何闪现的——数码相机闪光灯的使用技巧

闪光灯是一个用途非常广泛的辅助工具，它是摄影光源的一种，当拍摄时，周围环境的自然光源或人工光源不足的时候，闪光灯就成了弥补这一不足的光源。闪光灯所发出的光线与自然界中的光线不同，自然光线是连续不断的，而闪光灯是在曝光瞬间释放出来的强烈光线，没有经验的新手在使用数码相机闪光灯时往往会操作不当，无法达到理想的摄影效果，因此使用闪光灯时更需要掌握一定的技巧。     

激发无限可能Sony首台3LCD激光投影发布

人类对光的探索由来已久，对光的驾驭能力见证了科技的不断攀升。在投影领域，经历了传统灯泡光源统治的漫长时间，索尼激光光源投影机的研发及问世，将为投影机的发展开拓新的方向。     

纳米精度位移与振动干涉测量装置

该产品一种纳米精度位移与振动干涉测量装置，包括波长不相同的带有第一驱动电源和温度控制器的光源，调整光路准直用的准直光源和使被测物体产生振动的激振光源。光束传送的全光程都是在光纤、合波元件和光纤耦合器中进行。有两个光电转换元件响应波段只是对应光源发射光束的波段，对准直光源和激振光源发射的光束不反应。在第一驱动电源和模数转换器之间连接有控制初始相位的相位控制器。     

Acer宏碁发布LED镭射混合光源投影机

2012年是投影机产业的普及年，新光源具有寿命长，广色域色彩，即开即关的特性，为投影机产业的发展注入强心剂，在新光源市场领先就能代表在产业的领先性。Acer宏碁于7月5日在北京举办主题为“新光源心动色彩”的LED镭射混合光源投影机发布会。宏碁正式发布了两款LED镭射混合光源投影机，定位家用的K750投影机以及定位商用的K520投影机，同时也展示了全新升级的Acer宏碁全家族LED产品：超便携LED投影机K130、超级笔记本伴侣C120和经典款500流明家用LED投影机K330。     

色温与白平衡

何为色温 人们常用“冷”和“暖”来描述光线，它不是指光源产生的热量，而是跟它的颜色有关，这就是说光源的色温。那么色温是什么呢？色温是光源光谱成分的物理标示，其单位为K。     

混合动力Optoma ZX210ST

ZX21OST采用的混合光源技术（S0lidStateLight）是第二代技术，也就是红蓝LED光源＋蓝色激光光源的配置。     

专业投影灯的性能及电子镇流器的制作

作为价格昂贵的耗材投影光源产品——投影灯，一直以来由于应用于专业的投影机上，价格一直居高不下，极大地限制了应用范围，以致于目前国内广大自制彩投爱好者及国产单片式投影灯厂家所用的光源不得不忍痛割爱。选用了发热量大、体积大、色温低及光效低的非专业投影光源的照明金卤灯，来充当专业的投影灯，其结果是成本低，但图像质量却大幅度降低。目前。国产专业的金卤投影灯．主要性能参数如下(外观见图1）：     

基于奇相干光源和量子存储的量子密钥分配协议

针对传统量子密钥分配协议使用弱相干光源带来的密钥生成率较低的问题,对光源进行优化,用奇相干光源代替弱相干光源,提出了基于奇相干光源和量子存储的测量设备无关量子密钥分配协议。对比了具有奇相干光源和量子存储的测量设备无关量子密钥分配协议与基于弱相干光源测量设备无关量子密钥分配协议的性能优劣。分析了基于奇相干光源和量子存储的测量设备无关量子密钥分配协议中,密钥生成率、最小退相干时间与安全传输距离之间的关系。仿真结果表明,引入奇相干光源大大减少了传统弱相干光源的多光子数,弥补了其在光源上的不足之处。随着安全传输距离的增加,密钥生成率随之降低,但基于奇相干光源和量子存储的量子密钥分配协议性能仍然较高。     

手指静脉识别传感器的光源设计

针对手指静脉图像采集系统中近红外LED光源的光强均匀性相对较差的问题,设计了一种等边三角形结构的光源阵列.通过应用近红外LED光源的数学模型和斯派罗法则优化两个相邻光源的距离,确定了两颗光源之间的最优距离为6.26 mm,对该光源阵列进行仿真形成面积为10 mm ×20 mm的均匀光照区域.对此光源阵列进行硬件实验,证明等边三角形结构的光源阵列比单排的光源阵列在均匀性和图像质量上更加突出.     

Light source position calibration method for photometric stereo in capsule endoscopy

ABSTRACT

For photometric stereo in capsule endoscopy, calibration of light source is crucial for improving the precision of surface normal estimation. Therefore, this paper presents an improved planar-mirror-based light source position calibration method: from captured images of light source and detected poses of planar mirror, light paths are retraced from camera to light source, and position of light source is triangulated with least square method. The contribution of this paper is that a refraction model of the planar mirror is employed in the retracement of light paths, thus the bias of light paths caused by refraction can be compensated and the position of light source can be estimated more precisely. The results of simulation and experiment show that the proposed method provides higher calibration accuracy than the current planar mirror-based calibration method and can improve the precision of subsequent photometric stereo-based 3D reconstruction.     

Simulating Natural Light

Simulating natural light is an interesting subject in computer graphics. Using the principles of meteorology, we build a sphere cap light source model . Unlike existing illumination or light source models, we consider the effects of both the ratio of direct light to diffuse light and the position of the sun under different weather conditions. We use an area light source to generate shadows and a point light source to generate the other effects. The ratio of the two types of light is adjusted by a brightness factor b while the position of the sun is determined by giving the light direction. In addition. a modifiable sphere cap is used to obtain modified penumbra which vary with illumination.     

Fabrication of UV range light guide plate

The light guide plate, as part of the backlight unit in a cellular phone or liquid crystal display, has evolved to meet market demands for low power consumption, high-luminance and high-quality displays. Along with the advance of the light guide plate, LEDs have undergone development as light source for light guide plates. Surpassing the limitations of LED emission in the visible light range, LEDs that emit UV light have been developed. In recent years, the UV light are used as a source of light of the air cleaner, and it is used as a source of light to activate the titanium oxide which is photocatalyst. But common UV light sources are either line or point light sources. We study surface illuminators that incorporate diffusers in the visible light range. Applying our existing technology, we constructed an unprecedented UV surface illuminator (surface light source) and measured it using a photocatalyst. The experiment results are presented in this report.     

基于遗传算法的车灯线光源优化设计

采用遗传算法建立了遗传算法曲面反射点搜索模型,将其用于特殊反射点的寻找。经过多次试验确定遗传算法中所涉及参数的值,最终找出抛物面上的特殊反射点,建立线光源发光功率(P)和线光源长度(L)的函数关系,求出最低功率时线光源的长度。实验表明,该模型算法准确,速度快,收敛性好,适应性强,适用于非规则的,任意曲面点的搜索。     

Shading with Curve Light Sources1

A new shading model for curve light sources is presented. It accounts for both diffuse reflection and specular reflection of the illuminated surface. By regarding a linear light source as a directional quadrilateral light source with very small width, a simple formula is derived first for calculating the diffuse reflection component due to the illumination of the linear segment. The diffuse reflection of the surface by direct illumination of a curve light source is then evaluated by approximating the curve light with a series of linear segments. The specular reflection component due to a curve light source is represented by an integration taking Phong's specular model as the kernel and evaluated by summing the contributions from the linear segments. Finally, an efficient shadow detection algorithm for curve light sources is proposed. The images rendered with the shading model are very photo-realistic.     

Construction of a model of a continuous light source specified by a fixed set of rays

A physically correct model of a light source specified by a finite set of rays obtained either by processing the measured characteristics of the light source on the Radiant Imaging goniometric system or as a result of the forward stochastic ray tracing in a scene modeling the radiation of a complex light source is constructed. An algorithm for constructing a continuous emitting surface of a light source and its goniometric diagram given a finite set of rays is developed. The model preserves the spectral composition of the source rays in the surface luminance distribution of the radiation light source. An example of the photorealistic rendering of a scene illuminated by a finite set of rays obtained by the computer processing photometric measurement data.     

近红外指静脉图像采集系统设计

针对指静脉身份认证需求,以手指静脉图像采集系统作为研究对象,设计了基于单侧光源与反射镜面相结合红外光源可调控的指静脉图像采集系统。研究了LED光源位置与角度对静脉图像质量的影响,提出了基于图像质量评价的指静脉认证方法,并运用实测方法进行了验证。实验结果表明:可以得到与传统正面光源采集同等质量的静脉图像,具有更高的认证通过率,达到98.8%,并更易于用户使用。     

车灯线光源优化设计及其反射光亮区的计算机模拟

文章以汽车的一种典型车头灯的线光源优化设计为例,建立了满足具体设计规范的线光源优化设计的非线性规划模型。将线光源离散化为点光源,采用数值方法求出了该模型的最优解。根据所建的模型,用计算机模拟了线光源反射光在测试测试屏上的亮区形状和亮度。