基于CORDIC算法的全景图像畸变场校正算法

本文给出了全景图像畸变场校正算法,这种方法主要利用CORDIC(Coordinate Rotation Digital Computer)算法,提出了将圆环域图像展开成矩形图像的硬件快速算法.利用流水线CORDIC结构来实现高速高精度的三角函数发生器的设计,进而实现该校正算法.给出了该校正算法的结构及VHDL描述、综合及实现过程.     

足球机器人全景图像反畸变算法研究及其软件实现

本文在对全境图像产生畸变原因分析的基础上,利用最小二乘非线性拟合算法,建立了反畸变数学模型.在Visual C++6.0平台下编写程序,通过实物实验,证明反畸变数学模型正确.把全景图像反畸变软件系统DigitalImageProcess添加到足球机器人系统中,实现了快速实时全景图像校正,而且取得了良好的校正效果,实验证明该软件系统具有良好的实时性和快速性.     

FPGA软硬件协同处理实时图像处理系统

基于PC机图像处理系统实时性不强,DSP+FPGA图像处理系统的成本高、资源利用率低,单纯使用FPGA硬件实现的图像算法类型较为单一,针对这一系列问题,提出了一种基于FPGA软硬件协同处理的实时图像处理系统.采用一片FPGA芯片作为系统的核心,利用CCD相机等采集图像,通过SSRAM将图像缓存,以SOPC为控制核心,协调软硬件共同进行图像处理.易于使用硬件实现的图像处理模块(如滤波、形态学算法、图像校正、边缘检测等)均使用Verilog HDL语言实现,通过SOPC控制这些图像处理模块,实现相应的图像处理功能;而硬件难于实现的部分(如流程控制、复杂的分支判断)则使用SOPC中的CPU来实现.实验表明,系统卖时性强、图像处理速度快、可进行复杂图像算法的运算,同时具有设计简单、应用灵活、成本低的特点.     

基于FPGA实现医用电子内窥镜畸变图象实时校正的研究

本文针对医用电子内窥镜广角成像系统图像采集过程中存在的光学畸变色差^[1],提出了一种有效的实时校正技术。这种技术充分利用FPGA的优点：集成度高、速度快和易于实现复杂逻辑功能,设计出实时电镜畸变图象校正系统。采用硬件实现图象的畸变实时校正,不仅达到了减小系统光学结构体积、降低系统造价的目的,而且提高了诊断的准确性,改善了电镜系统的性能,使医用电子内窥镜在临床诊断和医学研究方面成为更加可靠和有效的手段。     

基于FPGA实现医用电子内窥镜畸变图象实时校正的研究

本文针对医用电子内窥镜广角成像系统图象采集过程中存在的光学畸变色,提出了一种有效的实时校正技术.这种技术充分利用FPGA的优点集成度高、速度快和易于实现复杂罗辑功能,设计出实时电镜畸变图象校正系统.采用硬件实现图象的畸变实时校正,不仅达到了减小系统光学结构体积、降低系统造价的目的,而且提高了诊断的准确性,改善了电镜系统的性能,使医用电子内窥镜在临床诊断和医学研究方面成为更加可靠和有效的手段.     

基于NIOSⅡ的高分辨率图像采集系统设计

介绍了一种基于NIOSⅡ的高分辨率图像采集系统的设计.系统以NIOSⅡ软核处理器为主控制器,配合高像素CMOS图像传感器、大容量SDRAM、高速DAC器件,实现高速高分辨率数字图像采集与实时显示.详细阐述了将Bayer图像转化为RGB图像的算法原理及其FPGA硬件实现,同时还给出了系统中其他各模块的FPGA硬件实现及其时序仿真图.系统提供了灵活的图像数据传输接口,可满足大多数工业应用.     

基于NIOSII的红外图像实时非均匀性校正

实时红外图像非均匀性校正是红外热成像系统的基础.采用Altera公司的NIOSII嵌入式软核CPU技术,提出了一种基于非线性拟合的实时校正方法以及利用FPGA为核心的硬件实现途径.针对校正中耗时的算法用FPGA中模块完成,采用NIOSII处理器的自定制指令,使FPGA的并行性和DSP的灵活性完美结合在一起,极大的提高了系统的性能.该方法动态范围大,系统仅采用一片FPGA芯片,使得系统小型化成为可能.介绍了硬件电路的原理图以及工作过程并给出实验结果.实验证明了这种方法的优越性,并取得了满意的实验结果.     

基于DSP的全景视频多目标实时检测

全景视频由于具有360?的视角,非常适合用于智能视频监控中的多目标检测。首先介绍了以DSP处理器为核心的系统处理平台;接着介绍了全景图像的展开算法和MHOEI多目标检测算法;然后针对全景展开设计了适合DSP平台的分块查表展开方法,针对MHOEI设计了降分辨率处理方法;最后在DSP处理器上进行了优化实现。实验表明,在所选的DM6437处理器上,将720×576大小的全景图像展开为896×180大小的目标图像,展开帧率可达120帧每秒;再经过多目标检测后能达到平均35帧每秒,满足实时要求,同时能有效检测出全景视频中的运动和静止目标。     

基于图像透视畸变自动校正的仪表判读方法

通过摄像机自动旋转判读360°空间内的多台仪表是比较有优势的计算机视觉判读仪表方案,但由此造成的倾斜拍摄会使表盘画面严重畸变.因此设计了一种能够在任意拍摄角度下自动校正仪表图像畸变的判读算法.首先通过设计定位校正板从背景中自动提取表盘图像,然后以此板上的校正标识为基础利用LM算法迭代建立8参数透视畸变模型将表盘校正回真实形状,实现仪表高精度判读.     

四边形分片逼近控制点的图像畸变校正算法

针对传统的图像畸变校正算法建模复杂、实时性差且图像信息易丢失等缺点,提出了一种基于四边形分片逼近控制点的图像畸变校正算法.该方法以标准点阵图像作为量测目标,将数学形态学和滑动邻域操作相结合以确定畸变图像像素点质心,采用基于四边形分片逼近的方法来拟合高次多项式校正模型,运用两步一维线性灰度级插值向后映射算法确定输出图像中像素点的灰度.将该算法在TMS320DM6437 DSP上实现,实验结果表明,校正一幅像素为768×494的图像所用的时间为0.036 S,畸变校正的误差在0.31个像素以内,有效地避免了边缘信息丢失、空洞及灰度失真现象.     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。