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Full-Text Articles in Life Sciences
Off-Line Data Evaluation Of Elemental Maps Obtained From Scanning Nuclear Microprobe Analyses, N. E. G. Lövestam, E. Swietlicki
Off-Line Data Evaluation Of Elemental Maps Obtained From Scanning Nuclear Microprobe Analyses, N. E. G. Lövestam, E. Swietlicki
Scanning Microscopy
The results of scanning nuclear microprobe (SNM) analyses are normally presented as elemental maps showing the number of detector events, acquired within a certain energy region, for every pixel irradiated. Such elemental maps can be misleading if they are interpreted as directly reflecting the variations in the elemental concentrations across the analysed sample. The aim of this paper is to demonstrate how such elemental maps can be treated in order to facilitate the interpretation and extract the information contained in the data set, such as the covariation between elements. Examples of sample thickness correction, image processing and spectrum filtering as …
Image Processing Procedures For Analysis Of Electron Back Scattering Patterns, N. C. Krieger Lassen, D. Juul Jensen, K. Conradsen
Image Processing Procedures For Analysis Of Electron Back Scattering Patterns, N. C. Krieger Lassen, D. Juul Jensen, K. Conradsen
Scanning Microscopy
At present, computer-aided Electron Back Scattering Pattern (EBSP) analysis often requires large amounts of operator time if statistically reliable measurements are needed. This paper presents ways to automatically detect and localize bands in EBSPs and thereby enable fully automatic EBSP analysis. The main focus will be on a procedure using a modified Hough transform by which more than 12 bands in a typical EBSP can be detected and localized. This procedure seems as effective and reliable for extracting the bands of EBSPs as any human operator. The performance of this procedure is compared with that of other image processing procedures.
Measurement Of Electron-Optical Parameters For High-Resolution Electron Microscopy Image Interpretation, A. F. De Jong, A. J. Koster
Measurement Of Electron-Optical Parameters For High-Resolution Electron Microscopy Image Interpretation, A. F. De Jong, A. J. Koster
Scanning Microscopy
A method is presented to measure various electron-optical parameters needed for high-resolution electron microscopy image interpretation with high accuracy. The method is based on the measurement of a series of beam-tilt induced image displacements. The displacements are calculated via cross-correlation of the images, and subsequently fitted to a third-order polynomal in the beam tilt. From two series of images (using the x and y beam tilt coils), the spherical aberration constant of the microscope can be measured, as well as the current values of defocus, beam tilt and astigmatism. The spherical aberration constant of three Philips microscopes is measured with …
Acquisition Hardware For Imaging, Peter Rez, J. K. Weiss, W. J. De Ruijter
Acquisition Hardware For Imaging, Peter Rez, J. K. Weiss, W. J. De Ruijter
Scanning Microscopy
In electron microscopy images can either be recorded in parallel (Transmission Electron Microscopy) or acquired as the variation in a signal as a probe is scanned over the specimen (Scanning Electron Microscopy). To extract the most information from an image requires that the best possible systems are used for acquiring image data. Ultimately, the limit to information capture is achieved when every electron from the scattering event of interest is recorded. The ideal system can be realised both for parallel recording with scientific grade CCD cameras, and for scanning microscopy with single electron counting electronics. The data rates from these …
On-Line Processing And Computer Control In High Resolution Transmission Electron Microscopy, F. A. Ponce, H. Hikashi
On-Line Processing And Computer Control In High Resolution Transmission Electron Microscopy, F. A. Ponce, H. Hikashi
Scanning Microscopy
Recent advances in hardware and software make it possible to perform real-time image processing, and to do simultaneous analysis of the image characteristics in the transmission electron microscope (TEM). We have used a commercially available image processor and a suitable computer/TEM interface to build a automated computer-control system for a JEOL 4000EX TEM. We report here the characteristics of the system, which has direct access to all electronic controls of a JEOL 4000EX. The various microscope parameters are set by changing one parameter at a time while the image processor measures a specific image variable such as the variance. From …
The Application Of Multispectral Techniques To Analytical Electron Microscopy, P. G. Kenny, M. Prutton, R. H. Roberts, I. R. Barkshire, J. C. Greenwood, M. J. Hadley, S. P. Tear
The Application Of Multispectral Techniques To Analytical Electron Microscopy, P. G. Kenny, M. Prutton, R. H. Roberts, I. R. Barkshire, J. C. Greenwood, M. J. Hadley, S. P. Tear
Scanning Microscopy
The York multispectral analytical electron microscope (MULSAM) was the first instrument specifically designed to acquire and process multiple Auger, X-ray, backscattered electron, elastically scattered electron, scanning electron microscopy (SEM) and specimen absorption current images simultaneously. Analyzing combinations of these signals with multispectral correlation techniques yields more information than would normally be obtained by treating each image separately. This paper reports some of the multispectral methods we have investigated at York which may be of use to other workers. Included are (1) a method that corrects for beam current fluctuations during long acquisition runs which is based on the anti-correlation between …
Atomic Resolution Electron Holography, K. Ishizuka, T. Tanji, A. Tonomura
Atomic Resolution Electron Holography, K. Ishizuka, T. Tanji, A. Tonomura
Scanning Microscopy
It has been demonstrated that electron holography is a very powerful tool to investigate an electromagnetic potential in medium resolution, since the phase of an electron wave is approximately proportional to the potential. Now, electron holography is at the second stage of development: to establish holography at atomic resolution and further to realize Gabor's idea to improve the resolution restricted by the spherical aberration of the objective lens. We investigate the possibility of electron holography to get information at atomic resolution by computer simulations as well as by digital processing of electron holograms. We show that the phase distribution has …
A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart
A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart
Scanning Microscopy
A common problem with electron micrographs of biological objects is that fine details are usually faint and, moreover, tend to be obscured by background noise from stain and support film. Filtering is a useful way to improve the signal-to-noise ratio and is particularly important when trying to detect small changes (conformational or due to labelling) or when examining frozen hydrated objects, where the statistical definition of the image has been reduced because of the low-dose conditions needed to prevent radiation damage. Filtering can also be used to address the superposition effects that result from the large depth of focus of …
Processing Multi-Spectral Scanning Electron Microscopy Images For Quantitative Microfabric Analysis, N. K. Tovey, D. L. Dent, W. M. Corbett, D. H. Krinsley
Processing Multi-Spectral Scanning Electron Microscopy Images For Quantitative Microfabric Analysis, N. K. Tovey, D. L. Dent, W. M. Corbett, D. H. Krinsley
Scanning Microscopy
Multi-spectral image analysis is a powerful method to characterise quantitatively the mineralogy and microfabric of soils, sediments, and other particulate materials. Backscattered scanning electron microscope (SEM) images of polished, resin-impregnated samples are grouped with the corresponding X-ray elemental maps using classification methods commonly used in remote sensing. However, the resulting mineral-segmented images require processing to render them suitable for quantification. In the past, this has been done subjectively and interactively, but the new objective methods described in this paper largely eliminate this subjectivity. An intensity gradient magnitude image of the original backscattered electron image is used as the basis of …
Image Segmentation Applied To Scanning Electron Microscopy Multi-Images Of Weathered Stones Of Monuments, M. Rautureau, R. Harba, G. Jacquet
Image Segmentation Applied To Scanning Electron Microscopy Multi-Images Of Weathered Stones Of Monuments, M. Rautureau, R. Harba, G. Jacquet
Scanning Microscopy
This paper describes a three complementary images processing method. The three images are coming from a scanning electron microscope (SEM) during the analysis of a particular stone: the Tuffeau used in most monuments of the Loire valley (France). The goal is to separate two classes of particles (calcareous and siliceous) from the porosity to give more information to experts who evaluate the damage of weathering on monuments. A specific process is developed: a first threshold on the good quality image allows separation of particles from porosity. Then, the complementarity of the three images gives the two other thresholds. Granulometry, percentages …
Digital Image Processing Of Electron Micrographs: The Pic System Ii, Benes L. Trus, Michael Unser, Thierry Pun, Alasdair C. Steven
Digital Image Processing Of Electron Micrographs: The Pic System Ii, Benes L. Trus, Michael Unser, Thierry Pun, Alasdair C. Steven
Scanning Microscopy
The PIC system, an integrated package of Fortran programs and subroutines designed to run on the Digital Equipment Corporation VAX family of computers, has been developed for analysis of electron micrographs with emphasis on the particular requirements for structural analysis of biological macromolecules. The substantially improved VAX version of PIC reported here has been developed from an earlier PDP-11 version which was, in turn, developed from a set of IBM 370 programs called MDPP. PIC now encompasses over 150 commands or processing operations that afford a comprehensive range of image processing operations including image restoration, enhancement, Fourier analysis, correlation averaging, …