以SPOT5遥感数据为例比较基于像素与面向对象的分类方法

以SPOT5高空间分辨率遥感影像为研究数据,采用面向对象的遥感影像分类方法,将基于像素的分类精度与基于影像对象的分类精度进行对比分析。结果表明:基于像素的分类方法在处理高空间分辨率遥感影像时具有一定的局限性,而面向对象的分类方法充分利用了影像中的光谱信息、几何结构、空间信息及上下文信息,在高空间分辨率遥感影像分类方面更具有优势,有良好的应用前景。     

一种新型小型化高分辨率LED矩阵显示器

介绍了一种与武器装备小型化、智能化、信息化相适应的一种新型光电混合集成器件-小型化高分辨率LED矩阵显示器的设计原理与设计实现,并介绍了水平、垂直两个方向高分辨率混合集成的工艺途径.     

基于Landsat８影像的额济纳荒漠绿洲植被覆盖度估算方法对比研究

荒漠绿洲是维持当地人类生存和社会发展的主要依托,但其地表植被稀疏,生态系统极其脆弱,而植被覆盖度是反映荒漠生态环境信息的重要指标之一.以黑河下游额济纳荒漠绿洲为例,基于Landsat８影像和野外实测植被覆盖度数据,对比和分析现有的适宜于干旱荒漠区的３类植被覆盖度提取方法(经验模型法、像元二分法和三波段梯度差法)在该区域的应用效果,并尝试利用基于转换型土壤调整植被指数(TSAVI)的像元二分模型法和修正的三波段梯度差法(MTGDVI)进行植被覆盖度估算,以期找到计算额济纳荒漠绿洲植被覆盖度的最佳模型. 研究结果表明:用TSAVI像元二分模型法的反演精度高而且能够较好地估算额济纳荒漠区域和绿洲区域的植被覆
盖度,适用于估算额济纳荒漠绿洲的植被覆盖度.     

加工中心运动误差在线视觉检测方法研究

介绍了当前对机床加工误差的几种检测方法,针对在线检测的要求,以TH5660A立式加工中心为研究对象,利用高分辨率的面阵CCD,提出了一种基于机器视觉的加工中心运动误差的在线检测系统方案.介绍了系统的硬件设计方案和软件总体设计方案.通过边缘检测、像素细分及边缘拟合等软件技术使测量精度突破像素级限制,达到亚像素级,可实现高精度检测.     

NDT data fusion at pixel level

No single non-destructive testing (NDT) technique or method is satisfactory to fully assess the structural integrity of a material. Indeed, each method presents some limitations in terms of defect detection and characterisation. Additionally, poor signal-to-noise ratio may make signal interpretation complex or unreliable. For these reasons, the concept of NDT data fusion — based on the synergistic use of information from multiple sources in order to facilitate signal interpretation and increase defect detection and characterisation — is expanding rapidly. A carbon fibre reinforced composite material previously subject to low energy impact damage has been non-destructively inspected using eddy current and infrared thermography. Following these non-destructive examinations, the information gathered from these two NDT methods has been fused at pixel level. Several well established and recognised data fusion processes based on statistical and probabilistic algorithms were used to combine eddy current and infrared thermographic data. The results obtained with these processes are presented in this paper and their efficiency discussed. It is shown that, in certain cases, NDT data fusion at pixel level may be adequate to increase knowledge about defect location and characterisation and to reduce ambiguity.     

低质量图像基于散射图SEM估计的MAP像素聚类方法

直方图是最常用的图像灰度统计分布的表示方法,二维直方图包括共生矩阵,灰度－边界值散射图,灰度平均灰度散射图等,本文提出了一种采用ＳＥＭ算法完成对灰－平均灰度的二维正态分布假设的参数估计,然后采用最大后验概率（ＭＰＡ）准则进行像素无监督聚类的图像分割算法,测试结果显示,我们的算法性能良好,尤其是对低对比度,有阴影和重噪声的低质量图像的分效果远优于其他基于散射图的阈值化方法。     

Image analysis system for quantitative metallography

This paper describes a Z-80 microprocessor-based image analyzer developed for global parameter evaluation of images over a 256 × 256 pixel frame. It consists of a microscope,ccd scanner, 6-bit videoadc, Z-80 computer and an image display monitor. Facilities are provided for feature erosion/dilation and halo correction. The paper also presents the details of another more powerful user microprogrammable HP1000 minicomputer-based image analysis system under development. This system consists of an optical microscope/epidiascope coupled to a chalnicon scanner. Here the 512 × 512 pixel image is acquired with 8-bit resolution. It provides for shading correction, auto-delineation, image processing and image analysis functions for evaluation of various basic and derived parameters. Both the systems are software intensive and are realised according to requirements of quantitative metallography. They can also be used for analysis of images obtained in the fields of biology, medicine, geological survey, photography and space.     

Parallel,overlapped, and intersected digital straight lines

A digital straight line is represented by a chain code of directions which satisfy Freeman's three criteria. Given two chain codes of digital straight lines and their starting pixels where their equations are not known, the paper will describe how to determine if they are parallel, overlapped, or intersected. An algorithm with only integer arithmetic is also implemented to find the intersection.     

屏幕坐标系中求任意曲线交点的一种方法

本文讨论了用光栅化比较法在屏幕坐标系中求任意曲线交点的一种方法，与传统的解析法相比，具有简单，准确等特点，且节省了大量的求交运算。     

参数曲线的分段步长生成算法*

介绍了参数曲线的现有逐点生成算法,并在此基础上提出了一个新的分段步长生成参数曲线的算法,对所绘制的曲线的每段分别使用不同的步长。验证了新算法的步长值优于现有算法的步长值,从而进一步解决了生成参数曲线的取点过密问题。实验结果表明,新算法所绘制的点数及运行时间都小于现有算法。