小波包变换在指纹图像压缩中的应用实现

小波包是近年来的一个研究热点,在图像处理方面有着广泛的应用.数据压缩是伴随小波分析产生最早的应用领域.指纹自动识别系统因其本身的特殊性对指纹图像压缩提出了特殊的要求.为此,简要的介绍了小波包变换的基本原理,给出了基于小波包变换的指纹图像压缩方法.     

基于小波变换的指纹图像压缩方法

小波分析是傅里叶分析方法的突破性进展，在非平稳信号处理中，取得了良好的效果。数据压缩是伴随小波分析产生最早的应用领域。指纹自动识别系统因其本身的特殊性对指纹图像压缩提出了特殊的要求。为此，简要的介绍了小波变换的基本原理，提出了一种新的指纹图像压缩评价准则并给出了基于小波变换的指纹图像压缩方法。     

高品质复杂光学系统自动设计程序开发与应用

介绍了自行开发的一种光学系统自动设计软件,突破传统计算方法,在应用高像差理论,多物距自动变焦距设计等方面,提出了复杂的处理思路,达到了比较理想的设计效果.特别是在光学微细加工领域,解决了许多特殊问题.着重介绍软件的鲜明应用优势、计算方法、关键技术难点的处理、程序结构和应用实例.     

Premiere中的两种特殊场景切换效果

本文主要介绍Pzemieze中的Jmage Mask和Gzadient Wipe两个特殊场景切换效果,初学者不太注意,特别是在使用Gzadient Wipe切换时,渐变灰度图是关键,故附实例图说明。     

人体热像诊断技术研究

本文介绍了人体体内的某些病症通过体表发射的红外辐射,由红外热像仪的显示器反映出体内细胞组织的温度变化,依据病患细胞细胞组织与其边沿细胞组织的温差数值及体内温度的对称性,能够对症症实行临床诊断,同时文中介绍了人体热像技术用于脉管炎的诊断方法。     

工业炉管温度的红外成像测试方法

针对工业炉内特殊的燃烧环境,从消除烟气影响切入,建立了红外计算模型,并利用红外热像仪获得运行状况中炉管表面二维温度场及其变化特征,为优化工艺操作提供了科学依据.     

稳像技术

介绍了稳像技术的应用领域以及光学稳像和电子稳像的各种实现技术,阐述了基于图像处理的电子稳像技术原理,并根据车载红外热像仪的特点,提出了简单可行的稳像方法。     

基于图像序列的红外锁相热像检测技术研究

介绍了红外锁相热像技术的发展和应用。红外锁相热像技术是一种主动热成像技术,采用了正弦调制光源作为激励源对试件进行激励,利用Cedip JADE MWIR 550焦平面红外热像仪采集红外图像序列,对其特殊的图像序列文件格式进行了分析,研究了数字信号的滤波算法和热波信号FFT处理算法,并采用Viscal C++开发平台编制了红外图像序列信号处理程序。试验结果表明,开发的基于红外图像序列处理的红外锁相热像软件系统可达到国外同类技术的先进水平。     

红外热像仪检测石化装置运行状况的应用研究

讨论了红外热像仪对裂解分馏塔底积焦，醋酸乙醛装置衬里损坏状况，电气设备热故障，裂解炉管热斑的测试方法及其热像特征，介绍了各种设备测试条件下标算发射率的方法，并对测试精度进行了探讨。     

像移补偿技术综述

航相机照相时不可避免的会产生像移,像移补偿是提高成像质量和相机分辨力必不可少的环节。首先通过分析像移的产生原因及对图像造成的影响阐述了像移补偿的必要性,然后介绍了目前国内外较多采用的像移补偿法原理及其应用范围,最后给出了一个应用多种像移补偿法相机的实例及像移补偿技术的发展趋势。     

红敏明胶波导全息图(WGH)

用红敏明胶拍摄波导全息图，并用CCD测量了材料的信噪比，采用这种红敏明胶拍摄的波导全息图，能有效地提高波导全息图的象质，为波导全息图的实际应用提供了可能。     

用波导全息照明器实现三维漫反射物体全息图的白光再现

提出了一种利用波导全息照明器实现三维漫反射物体全息图的白光再现新方法。利用反射全息图的波长选择性和波导全息照明器对菲涅耳全息图的色散补偿，用白光照明获得了清晰的准单色再现像。     

纳米材料在印制电路板基材中的应用

本文论述了纳米材料对印制电路板的力学性能、热性能、绿色化的影响,重点阐述了纳米材料对基材的提高阻燃性、力学性能、耐热性和降低基材的热膨胀系数的机理和应用。纳米材料由于其奇特的效应必将PCB基板材料的制造技术推向一个新的台阶,实现基材轻、薄、小的要求。     

量子点光电子器件及其研究进展

作为未来新型光电子器件的有源区材料,采用能带工程形成的各种半导体量子点,以其所具有的许多独特光电特性而日益显示出潜在的重要应用。着重评述了量子点激光器、量子点红外光探测器和量子点单光子发射器件在近3至5年内取得的最新进展,并对存在的问题进行了分析和讨论。最后,提出了进一步改善器件性能的几种可能途径。     

Broadband Pulsed Fiber Laser Generation with Topological Insulator: Towards the Mid-Infrared Regime

In recent years, topological insulators have aroused the attention of a great number of scientists due to their unique electronic structures and peculiar physical properties. Triggered by the similar electronic structures as graphene, the broadband nonlinear absorption properties of topological insulators were investigated. Moreover, the mode-locked or Q-switched fiber lasers based on topological insulators were realized for broadband operating wavelength. Here, we present an overview of the preparation, transferring, linear and nonlinear optical properties, and their applications of topological insulators in pulsed fiber lasers. The pulsed fiber lasers towards midinfrared regimes have been proposed.     

Recent progress in 2D group-V elemental monolayers: fabrications and properties

A large number of two-dimensional (2D) monoelemental materials with huge application potentials have been developed, since graphene was reported as a monoelemental material with unique properties. As cousins of graphene, 2D group-V elemental monolayers have gained tremendous interest due to their electronic properties with significant fundamental bandgap. In this review, we extensively summarize the latest theoretical and experimental progress in group-V monoelemental materials, including the latest fabrication methods, the properties and potential applications of these 2D monoelementals. We also give a perspective of the challenges and opportunities of 2D monoelemental group-V monolayer materials and related functional nanodevices.     

On unique, multiset, and set decipherability of three-word codes

The concepts of unique decipherability (UD), multiset decipherability (MSD), and set decipherability (SD) of codes were developed to handle some special problems in the transmission of information. In unique decipherability, different sequences of codewords carry different information. In multiset decipherability, the information of interest is the multiset of codewords used in the encoding process so that order in which transmitted words are received is immaterial. In set decipherability, it is the set of codewords that is relevant information so the order and the multiplicity of words are immaterial. Lempel (1986) showed that the UD and MSD properties coincide for two-word codes and conjectured that every three-word MSD code is a UD code. Guzman (1995) showed that the UD, MSD, and SD properties coincide for two-word codes and conjectured that these properties coincide for three-word codes. In this paper, we answer both conjectures positively for all three-word codes {C₁, C₂, C₃} satisfying |C₁|=|C₂|⩽|C₃ |. Our procedures are based on techniques related to dominoes     

Permeability measurement on composites made of oriented metallicwires from 0.1 to 18 GHz

In this paper, we study the microwave properties of strongly anisotropic materials made of orientated conducting wires. We have developed a broad band method to determine their permeability μ∥ parallel to the direction of the wires. We investigate the magnetic properties of strongly anisotropic composites made of different types of paramagnetic and ferromagnetic wires. A simple model is proposed to account for the skin effect, and agrees with our observations. This leads to a unique broad band method for measuring the permeability of thin conducting wires     

纳米硅异质结二极管

在 p型单晶硅衬底上沉积一层掺磷 N+ 型纳米硅薄膜 ,形成 nc- Si∶ H/ c- Si构成的 N+ / p异质结构。文中报道了它的独特性能 :其反向击穿电压可达 75V,反向漏电流仅 n A量级 ,反向开关时间为 1.5ns,可望应用于微波波段。由其 I- V及 C- V特性初步分析了结的性质及电输运机制。     

石墨烯/硅基异质集成光电子器件

石墨烯/硅基异质集成的光子器件研究在近年来取得了巨大进展,因石墨烯所具有的诸多独特的物理性质如超高载流子迁移率、超高非线性系数等,石墨烯/硅基异质集成器件展现出了诸如超大带宽、超低功耗等优异性能。文章介绍了近年来报道的典型石墨烯/硅基异质集成器件,包括石墨烯/硅基电光调制器、石墨烯/硅基热光调制器和石墨烯/硅基光电探测器,简要阐述了其原理与性能,并对其未来的应用与发展做出了展望。