A comparison of on-line digital recording with conventional photographic recording for scanning electron microscopy

The scanning electron microscope (SEM) has previously utilized a video monitor plus camera as the image recording system. However, this conventional method is inefficient in relation to information present in the original electric signal. Therefore, we propose, for general use, an on-line recording system consisting of an A-D converter, image memory, and computer. In addition, we found that the effect of vibration in the SEM image could be reduced by application of the digital recording system. In the present study, interpolation and signal averaging programs were utilized for confirming the performance level of the on-line recording system. These programs were found to be very effective for SEM.     

A simple method for the acquisition of high-quality digital images from analog scanning electron microscopes

A method is described for converting video signals of analog scanning electron microscopes (SEMs) into digital images of high quality. A plug-in card commercially available for personal computers is used for the on-line analog/digital conversion. A Windows application program written by the authors, together with low-level software drivers supplied with the plug-in card, allow digital images to be recorded, to be displayed simultaneously on the computer monitor and to be saved as a file in a standardized format. Compared to conventional photographic images obtained from the SEM camera system, the digital images possess superior sharpness of outline, excellent image definition, diminished noise and well-defined grey-scale tones. This method provides SEM images of high quality for less than $1000 from most older analog SEMs. In addition, the advantages of digital image processing can be applied to analog SEMs, including contrast enhancement, digital filtering and multichannel recording.     

Automatic contrast adjustment for detail recognition in SEM images using on-line digital image processing

A new digital filter method has been developed for enhancement of detail recognition in SEM images of high signal-to-noise ratio using an on-line digital image processing system. The filter allows an automated improvement of the presentation of SEM image information and utilizes a median filter of very large mask size and histogram equalization. Since the method can be performed without input of any processing parameters, the user simply pushes a button for obtaining the processing result similar to conventional photo recording. The method utilizes digital signal processors for establishing high speed, hence, the processing results can be immediately assessed. When Applied to a variety of field-emission SEM images, there were no problems with inconvenient artifact encountered.     

A real‐time image dynamic range compensation for scanning electron microscope imaging system

This paper presents the development and implementation of a real‐time dynamic range compensation system for scanning electron microscope (SEM) imaging applications. Compared with conventional automatic brightness contrast compensators that are based on the average image or pixel intensity level, the proposed system utilizes histogram‐profiling techniques to compensate continuously the dynamic range of the processed video signal. The algorithms are implemented in software with a frame grabber card forming the front‐end video capture element. The proposed technique yields better image compensation compared with conventional methods.     

Microcomputer system for ion microscopy digital imaging and processing

Analytical ion microscopy is a powerful tool for biological tissue analysis as it allows direct chemical distribution imaging, even at low element concentrations. A microcomputer based digital imaging system achieving acquisition at low light level is presented. It includes a high sensitivity video camera connected to a specialized image processor subsystem. Acquired images consist of 512 times 512 pixels with 8 bits accuracy. Real-time image processing software has been implemented so that image processing may be performed on-line. Image processing software allows off-line image manipulation and correlation for biological interpretation of elemental mapping images. System capabilities are illustrated by a study of stable and radio iodine mapping in rat thyroid tissue.     

Automatic measurement of scanning beam diameter using an on-line digital computer

A method for the measurement of electron probe beam diameter by digital image processing has recently been published. The purpose of the present report is to describe the development of an automatic system for beam diameter measurement. To complete this system, a method based on a theory which combines automation and high-resolution conditions is proposed. In practice, the beam diameter is measured from the STEM image of a crystalline hole in a gold thin film, utilizing an on-line computer system equipped with newly developed digital processing programs linked to a SEM in the transmission mode. The functions of the programs include statistical processing, matching, noise removal, interpolation, selection, and rotation. By combining these functions, the scanning beam diameter is accurately measured, in spite of difficulties, under most electron microscope operating conditions. The user simply appoints the edge included in the STEM image.     

On-line image processing in high resolution electron microscopy

On-line processing and analysis of high resolution electron microscope (HREM) images has been implemented using a software controlled image processor based on a commercial digital video framestore. It directly digitizes the output from the low light TV camera on the HREM and applies any processing necessary. The conditions under which images from amorphous specimens are being obtained can be established on-line. The fast fourier transforms (FFTs) of 256 times 256 pixels produced in 15 s with the system off-line are comparable to those from diffraction analysis of the same data on a laser optical bench. The precision of analysis of defocus, aberrations and astigmatism on-line is discussed, together with possible approaches to routine analysis of crystalline specimens and for interactive control.     

A natural color scanning electron microscopy image

A method for obtaining a scanning electron microscopy (SEM) image with natural color information (NCSEM image) has been developed by using an SEM operated under low vacuum or low voltage, a video microscope (VM), and a high-performance personal computer. In order to produce an NCSEM image with both the fine structures of the SEM image and the color information included in the VM image, an improvement of the depth of focus in VM image is required. This can be successfully performed by some digital image processing techniques. A difference in resolution between the SEM image and the VM image does not disturb our study as shown in the text. In addition, the well-known hue, saturation, intensity (HSI) color model, which is frequently utilized for color image manipulation, was originally altered for the present purpose.     

利用I^2C总线实现DSP对SAA7113H的配置

在视频图像系统的前端,通常需要视频解码芯片完成模拟视频图像的数字化转换。本文介绍了一款高性能的视频输入处理芯片SAA7113H的功能和特点以及初始化时的寄存器配置,着重阐述了利用DSP TMS320VC5509的I^2C总线实现对SAA7113H初始化配置的方法。可以在许多的视频图像采集系统中得到直接的应用。     

Stereological analysis in scanning electron microscopy.

The traditional field of stereological analysis based on quantitative image analysis data is expanded to include scanning electron microscopy (SEM). Two major methodological advances enable useful results to be obtained: 1) Image recording of backscattered electrons using an annular semi-conductor detector; 2) Direct link between SEM and image analyser by means of an on-line coupling providing synchronisation of both sub-systems.     

Streak camera-TV system with improved S/N ratio incorporating a digital video recorder directly interfaced to a computer

By incorporating a digital video recorder, a streak camera system previously developed for recording time-resolved transient absorption and emission spectra was greatly improved with respect to reproducibility and accuracy. The requirements for on-line computer time were also reduced.     

便携式仪表数字图像采集与处理技术

随着USB摄像头技术的普及、嵌入式技术的迅速发展以及数字图像处理技术的成熟完善,以往依托计算机进行数字图像处理的诸多仪器和设备可实现便携化。用摄像头采集数字图像,通过USB接口输入嵌入式开发板中实现各种数字图像处理算法如去噪声、图像分割、边缘检测、图像匹配及图像代数运算等算法,处理结果从LCD显示屏显示,这样就构成了一个便携式系统。     

基于硬盘的视频实时存储方法的研究

数字图像的实时存储是视频判读的基础,经常使用模拟录像机把视频信息记录在磁带上,由于磁带录像机的分辨率不高,影响判读的精度.本文针对数字图像的特点,提出了一种新型的、基于计算机硬盘的视频存储方法,其目的是简化判读系统的结构,提高判读的精度.它利用了数据压缩原理,对视频信号进行实时、无失真的压缩,再把压缩后的数据进行存盘,实现了视频图像实时存储.试验表明,用此方法可以完成512×512的视频图像的实时存储,且结构简单,方法实用,是一新型的视频存储方法.     

基于DM642的视觉假体图像采集与处理系统

现研究的是基于DM642的视觉假体图像采集与处理系统,是视觉假体微机电系统的初步模拟,是利用高端数字图像处理芯片和CMOS图像传感器开发的一个系统。这样的一套系统是设想在正常人眼的视网膜不能正常工作时对它进行代替。由CMOS图像传感器采集视频信号,经过高端的数字图像处理芯片的处理,并行输出电极刺激信号。     

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.     

Quality improvement of environmental secondary electron detector signal using helium gas in variable pressure scanning electron microscopy

The quality of the image signal obtained from the environmental secondary electron detector (ESED) employed in a variable pressure (VP) SEM can be dramatically improved by using helium gas. The signal-to-noise ratio (SNR) increases gradually in the range of the pressures that can be used in our modified SEM. This method is especially useful in low-voltage VP SEM as well as in a variety of SEM operating conditions, because helium gas can more or less maintain the amount of unscattered primary electrons. In order to measure the SNR precisely, a digital scan generator system for obtaining two images with identical views is employed as a precondition.     

New generation scanning electron microscopy technology based on the concept of active image processing

A new generation of scanning electron microscopy (SEM) technology is proposed based on the concept of “active image processing.” In order to collect sufficient data for a purpose which is defined in the utilization of active image processing, we may need more devices from among a variety of useful hardware, for example, a digital scan generator with meaningful parameters and an analog-to-digital converter for ultrahigh density recording. After the data acquisition, the application of some digital image processing techniques is certainly effective, because the method in question is specially designed so that the property of obtained data will be suitable for the application of these techniques. The present technology should produce a variety of attractive options in the field of SEM.     

基于PCI总线的数字视频键控图像叠加卡的设计

设计了用于虚拟演播室的PCI总线数字视频键控图像叠加卡。该卡能实时完成背景数字视频和前景图像视频的实时叠加，并可通过alpha键控制前景视频和背景视频的叠加比例，也可单独输出前景视线或背景视频。键控技术作为理论基础被扼要阐述。详细讨论了PCI总线数字视频键控图像叠加卡的基本结构、数字视频编辑码的方法。系统时序发生和叠加处理的基本原理。给出了编制和调试开发SAA7146多媒体桥的内核级WDM（Win 32 Driver Model）设备驱动程序的方法和步骤。     

Video microscopic image processing facilitates the evaluation of light microscopic autoradiography at high magnification

Light microscopic autoradiographs of H-thymidine labelled unstained semithin sections of Xenopus laevis embryonic nuclei were examined with conventional Nomarski differential interference contrast, phase-contrast and video microscopy. Whereas at low magnification it was possible to obtain a photograph of the nuclear structure and the silver grains in one focal plain, at high magnification, with small depths of focus, a satisfactory image was not attainable. Therefore, we stored the images of the two different focus levels with a digital image processing system and combined both images by an arithmetic operation. This video microscopic technique allows the use of high magnification light microscopy with oil immersion objectives and the application of additional electronic contrast enhancing methods for an adequate and rapid analysis of light microscopic autoradiographs.