A new approach for the automatic evaluation of the solidification structure in steel using orientational entropy filtering

We present a new method for the automatic evaluation of the dendritic solidification structure in metallurgical micrographs of solidified steel. The evaluation of the microstructural parameters such as the primary dendrite arm spacing and the primary grain size are of high importance due to their direct relationship with the internal quality and mechanical properties of the cast product. Given the repeated geometric features in the micrographs and the regular pattern in colour intensity, we applied a filter mask to determine the local entropies within the masks in order to detect the centre coordinates of each individual dendrite. The orientation of the dendrites was determined by rotating the filter mask over each pixel to find the orientation which corresponds to the lowest entropy value. The segmentation of the microstructure was then performed via Delaunay tessellation and subsequent transformation of the triangular mesh into a rectangular grid, enabling the determination of the desired microstructural parameters.     

Visualization and coding in three-dimensional image processing

A system for calculating orthographic views of three-dimensional objects from a confocal microscope has been implemented in a high-level language. It is used on a regular basis in a number of projects and on different computers. The system enables the user to filter the original data and make a selection of which points and parts of the objects to show in a projective view. The information to be shown is coded in a compact format that is well suited for projection calculations. Several display principles were implemented that enhance different aspects of the objects.     

In situ observation and interferometric characterization of solid–liquid interface morphology in directionally growing transparent model systems

The performance of a new directional solidification device dedicated to the characterization of solid–liquid interface morphology by means of optical methods is presented in this paper. In contradiction to usual solidification studies on transparent materials carried out on thin films, which eliminates the complex coupling between solidification and convection, this device enables in situ and real time studies on bulk transparent materials. The alloy is contained in a cylindrical crucible and observation is performed in two perpendicular directions: the growth one and the transverse one. In addition to direct observation by light transmission in those directions, an interferometer is also set up in the growth direction to provide information on the shape and the motion of the interface through an analysis of the interferometer fringes. The combined determination of solidification front characteristics by these three observation modes has already given critical information on interface dynamics: front recoil measurements during initial transient, formation of microstructure patterns, and influence of convection on the triggering of instabilities.     

Confocal microscopy and image processing in the study of plant nuclear structure

We describe measurements of the point spread function (PSF) for a confocal microscope and compare them with the PSF for a conventional (wide-field) fluorescence microscope. In situ hybridization with probes to telomere and ribosomal rDNA sequences, combined with three-dimensional (3-D) microscopy, has been used to study interphase nuclei in root tissue of Pisum sativum and Vicia faba. Nearly all the telomeres in both species are located at the nuclear envelope, and are highly clustered in the Vicia tissues, suggesting specific binding interactions. rDNA labelling in P. sativum shows four brightly staining knobs, corresponding to condensed regions of the rDNA genes from the two pairs of nucleolar organizer genes in this species, arranged approximately tetrahedrally around each nucleolus. Deconvolution using the measured PSFs can be used to improve these images, revealing a fibrous substructure in the perinucleolar knobs, and a large amount of interconnecting internal structure, which we suggest represents rDNA both in the fibrillar centres and also more diffuse, widely dispersed rDNA. Finally we show that accurate conventional data coupled with deconvolution can produce 3-D reconstructions comparable to those obtainable with confocal microscopy, but that the clearest images are obtained by applying deconvolution to the confocal data.     

电子显微镜在金属-半导体纳米线界面原位合金化中的应用

利用原位电子显微方法研究了金属-ZnSe半导体纳米线界面合金化过程,结果表明:在脉冲电流的作用下,ZnSe纳米线可以产生明显的焦耳热效应,导致金属-ZnSe纳米线界面发生合金化反应.通过调整纳米线与金属电极的接触面积,可将焦耳热效应准确控制在界面内,进而实现纳米尺度的合金化反应.     

焊接缺陷的X射线自动检测图像处理

X射线无损检测对于焊接结构件的质量保证具有重要意义。使用Image J图像处理软件和Java语言开发插件,对焊接点中气孔分布以及面积等缺陷参数进行自动检测并对获得的图像进行分析处理。提出利用区域标记法分割出有效分析区域,先去除无效区域后再对感兴趣区域进行气孔提取,相较于传统的全局图像差分法,可以减少背景对缺陷检测的影响,降低误判率。设计出的检测方法能够对特定图像进行批量分析,可以减少检测的时间。     

MRT letter: In situ observation method for microstructural changes of steel during hot deformation

We report on the result of an in situ method for observing microstructural changes during hot deformation. The observation of microstructural changes of steel at 1,473 K under tensile strain is demonstrated using the reported method. The development of deformed structures and the formation of a new grain boundary, which subsequently moved with increased strain, were clearly observed. The effectiveness of this method was confirmed by the results of several examples. © 2009 Wiley‐Liss, Inc.     

基于VC++的图像快速雕刻自动编程软件开发

本文介绍一种通过编程实现位图读取,并作为数据源,转换为G加工代码的自动编程方法。该方法用于激光快速雕刻实际中。可以大大提高用户在小批量、多品种的产品生产过程中的数控编程效率和生产自动化程度。     

棒材自动计数系统的设计与应用

棒材自动计数问题一直是困扰我国棒材生产企业的一个难题,目前我国棒材生产企业普遍采用人工计数方法.针对这种情况,通过采用现代化手段和技术创新,开发出适合我国钢铁企业的棒材自动计数系统,可以有效提高劳动生产率,把工人从繁重的体力劳动和恶劣环境中解放出来,力求为企业提供高科技设备,填补我国在该项技术上的空白.     

Interactive image processing with an off-line minicomputer: organization,performance and applications

A recently established facility for interactive image processing is described, primarily from the point of view of the system's hardware organization and the special purpose software provided to support it. The performance of more general software (the ‘Semper’ system) in the new environment has been measured carefully, and found to be about 10 times its performance on our previous PDP 8/E computer; particular attention is given to the data management techniques crucial to the system's efficiency. Some current applications are illustrated, including high resolution image interpretation and image averaging of biological crystals.     

一种SMT生产缺陷自动检测系统的设计与实现

为了控制PCB成品质量,设计和实现了对SMT生产缺陷的自动检测。采用定位、摄像和图像处理等技术,精确检测和标识PCB产品的缺陷。系统运行可靠,降低了SMT生产成本。     

Digital image tiles: a method for the processing of large sections

Segmentation of large areas of light microscopic slides into N by N fields, and each of these fields into M digital image tiles, allows the scanning, storage and digital processing of large images. Any of the original N² fields or composites of M adjacent tiles can be recalled to the video display for analysis. Developed procedures for use on a microscope equipped with a precision scanning stage allow registration of the image coordinates (X-Y) for any original or composite field and the alignment of one of these fields along the depth (Z) axis by means of external, machined fiducial marks in serial sections. To facilitate work whenever unavoidable, we have incorporated methods for digital image panning and zooming (changes of magnification) and discuss their use and implications.     

Digital image processing for nonperiodic objects and an on-line image processing system for high resolution electron microscopy

A digital image processing method for noise removal and image enhancement in nonperiodic structural images is described. The method for noise removal uses a reversible transform between an image and image autocorrelation function. The Laplacian filter is then employed for image enhancement. Furthermore, an on-line image processing system for highresolution TEM is presented.     

An easily built diffuse illumination system effective at both very low and moderate magnifications, for observing in situ stained slides

Effective study of in situ stained sections often requires illumination that is difficult to achieve with commonly used research microscopes. One must be able to switch quickly and conveniently from the very lowest to moderate magnifications. At all magnifications contrast due to light scatter must be minimized, so that the weak staining that signifies low gene expression can be observed reliably. For the lowest power objectives (e.g., 1.25× or 2×) many microscopes require that the condenser be removed to illuminate the full field of view. This is not only very inconvenient when switching magnifications, but without a condenser the low numerical aperture of the illuminating light beam results in unwanted contrast due to light scatter. We have devised a simple system that diffusely illuminates the full field of view of the lowest power objective (1.25×) and has high enough numerical aperture for use with the 25× and 40× objectives. A key feature is the use of a large diameter ring light (internal diameter 5.8 cm), placed on the microscope base, to illuminate a large diameter diffuser placed just below the slide.     

Nanowear Mapping: A Novel Atomic Force Microscopy Based Approach for Studying Nanoscale Wear at High Sliding Velocities

Most micro/nanoelectromechanical system (MEMS/NEMS) devices and components such as microgears and micromotors operate at very high sliding velocities (of the order of tens of mm/s to few m/s). Nanoscale tribology and mechanics of these devices is crucial for evaluating reliability and failure issues, including those stemming from high wear. We have developed a novel AFM based approach for studying nanoscale wear at sliding velocities up to 10 mm/s. The technique is demonstrated by mapping wear of silicon resulting from two- and three-body abrasions, and that of diamondlike carbon (DLC) resulting from phase transformation of DLC to a graphite-like phase. The novel AFM based approach for nanowear mapping provides a reliable as well as a fast means for investigating wear on the nanoscale as a function of normal load and sliding velocity.     

Recrystallization phenomena in an IF steel observed by in situ EBSD experiments

In situ electron backscatter diffraction microstructural analysis of recrystallizing interstitial free steels deformed to strains of 0.75 and 1.6 has been carried out in a FEG‐SEM. The experimental procedures are discussed, and it is shown that there is no degradation of the electron backscatter diffraction patterns at temperatures up to 800°C. Analysis of the surface and interior microstructures of annealed samples shows only minor difference, which suggests that in situ annealing experiments are of value. In addition, it is shown that in situ measurements allow a detailed comparison between the same areas before and after annealing, thereby providing information about the recrystallization mechanisms. Sequential recrystallization phenomena, such as initiation and growth of new grains, are observed at temperatures over 740°C, and depending on the deformation histories, different recrystallization behaviour is observed. It is found that {111}〈123〉 recrystallized grains are preferentially formed in the highly deformed material, whereas no strong recrystallization texture is formed in the lower strained material.     

基于图像处理技术的光纤准直器封装新方法

运用"可检测性"概念和Design For Test(DFT)方法,提出了一种基于图像处理技术的光纤准直器封装方法。在装配前利用机器视觉和数字图像处理技术保证插针到达正确相位,然后保持插针相位姿态不变插入不锈钢套筒,同时光纤插针做进给运动,以调节插针和自聚焦透镜在不锈钢金属套筒中的间隙,使插针快速地到达最佳装配位置,保证输出光功率最大。该系统主要由CCD摄像机、图像采集卡、系统控制和图象处理软件构成,由计算机控制其装配全过程。实验证明了该系统的有效性和实用性,其相位误差可控制在公差±3°内,满足光纤准直器装配精度要求。该封装方法已应用于生产,较大地提高了生产效率和产品合格率。     

Semi-automated software for the three-dimensional delineation of complex vascular networks

The understanding of tumour angiogenesis is of great importance in cancer research, as is the tumour response to vascular‐targeted drugs. This paper presents software aimed at aiding these investigations and other situations where linear or dendritic structures are to be delineated from three‐dimensional (3D) data sets. This software application was written to analyse the data from 3D data sets by allowing the manual and semi‐automated tracking and delineation of the vascular tree, including the measurement of vessel diameter. A new algorithm, CHARM, based on a compact Hough transform and the formation of a radial map, has been used to locate vessel centres and measure diameters automatically. The robustness of this algorithm to image smoothing and noise has been investigated.     

Survey: interpolation methods for whole slide image processing

Evaluating whole slide images of histological and cytological samples is used in pathology for diagnostics, grading and prognosis . It is often necessary to rescale whole slide images of a very large size. Image resizing is one of the most common applications of interpolation. We collect the advantages and drawbacks of nine interpolation methods, and as a result of our analysis, we try to select one interpolation method as the preferred solution. To compare the performance of interpolation methods, test images were scaled and then rescaled to the original size using the same algorithm. The modified image was compared to the original image in various aspects. The time needed for calculations and results of quantification performance on modified images were also compared. For evaluation purposes, we used four general test images and 12 specialized biological immunohistochemically stained tissue sample images. The purpose of this survey is to determine which method of interpolation is the best to resize whole slide images, so they can be further processed using quantification methods. As a result, the interpolation method has to be selected depending on the task involving whole slide images.