Journal articles: 'Optics. Image processing. Microscopy Electron microscopy'

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Faruqi, A. R., and Sriram Subramaniam. "CCD detectors in high-resolution biological electron microscopy." Quarterly Reviews of Biophysics 33, no. 1 (February 2000): 1–27. http://dx.doi.org/10.1017/s0033583500003577.

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1. Introduction 11.1 The ‘band gap’ in silicon 22. Principles of CCD detector operation 32.1 Direct detection 32.2 Electron energy conversion into light 42.3 Optical coupling: lens or fibre optics? 62.4 Readout speed and comparison with film 83. Practical considerations for electron microscopic applications 93.1 Sources of noise 93.1.1 Dark current noise 93.1.2 Readout noise 93.1.3 Spurious events due to X-rays or cosmic rays 103.2 Efficiency of detection 113.3 Spatial resolution and modulation transfer function 123.4 Interface to electron microscope 143.5 Electron diffraction applications 154. Prospects for high-resolution imaging with CCD detectors 185. Alternative technologies for electronic detection 235.1 Image plates 235.2 Hybrid pixel detectors 246. References 26During the past decade charge-coupled device (CCD) detectors have increasingly become the preferred choice of medium for recording data in the electron microscope. The CCD detector itself can be likened to a new type of television camera with superior properties, which makes it an ideal detector for recording very low exposure images. The success of CCD detectors for electron microscopy, however, also relies on a number of other factors, which include its fast response, low noise electronics, the ease of interfacing them to the electron microscope, and the improvements in computing that have made possible the storage and processing of large images.CCD detectors have already begun to be routinely used in a number of important biological applications such as tomography of cellular organelles (reviewed by Baumeister, 1999), where the resolution requirements are relatively modest. However, in most high- resolution microscopic applications, especially where the goal of the microscopy is to obtain structural information at near-atomic resolution, photographic film has continued to remain the medium of choice. With the increasing interest and demand for high-throughput structure determination of important macromolecular assemblies, it is clearly important to have tools for electronic data collection that bypass the slow and tedious process of processing images recorded on photographic film.In this review, we present an analysis of the potential of CCD-based detectors to fully replace photographic film for high-resolution electron crystallographic applications.

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de Ruijter, W. J., Peter Rez, and David J. Smith. "Recent Progress and Plans in Computer-Controlled High Resolution Electron Microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 154–55. http://dx.doi.org/10.1017/s042482010017952x.

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Digital computers are becoming widely recognized as standard accessories for electron microscopy. Due to instrumental innovations the emphasis in digital processing is shifting from off-line manipulation of electron micrographs to on-line image acquisition, analysis and microscope control. An on-line computer leads to better utilization of the instrument and, moreover, the flexibility of software control creates the possibility of a wide range of novel experiments, for example, based on temporal and spatially resolved acquisition of images or microdiffraction patterns. The instrumental resolution in electron microscopy is often restricted by a combination of specimen movement, radiation damage and improper microscope adjustment (where the settings of focus, objective lens stigmatism and especially beam alignment are most critical). We are investigating the possibility of proper microscope alignment based on computer induced tilt of the electron beam. Image details corresponding to specimen spacings larger than ∼20Å are produced mainly through amplitude contrast; an analysis based on geometric optics indicates that beam tilt causes a simple image displacement. Higher resolution detail is characterized by wave propagation through the optical system of the microscope and we find that beam tilt results in a dispersive image displacement, i.e. the displacement varies with spacing. This approach is valid for weak phase objects (such as amorphous thin films), where transfer is simply described by a linear filter (phase contrast transfer function) and for crystalline materials, where imaging is described in terms of dynamical scattering and non-linear imaging theory. In both cases beam tilt introduces image artefacts.

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Lichte, Hannes. "Electron Holography at Atomic Dimensions." Microscopy and Microanalysis 3, S2 (August 1997): 1169–70. http://dx.doi.org/10.1017/s1431927600012733.

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Many of the problems of transmission electron microscopy (TEM) are due to the fact that wave optics which governs the interaction of electrons with the specimen and the imaging process definitely is brought to an end with the detection of the final electron image. Unfortunately, resolution is limited by an increasing number of aberrations. Furthermore, wave optical tools in the electron microscope which are needed for example to produce phase contrast better than that given by the phase contrast transfer function, for distinction of amplitude contrast and phase contrast, or to measure phases in Fourier space, are only poorly developed. Since subsequent image processing of electron diffraction patterns or real space images can never compensate for the loss of phase information, the phase has to be recorded also, i.e. one has to work holographically to collect and reconstruct all data of the object structure.

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Krakow, William. "Applications of real-time image processing for electron microscopy." Ultramicroscopy 18, no. 1-4 (January 1985): 197–210. http://dx.doi.org/10.1016/0304-3991(85)90138-x.

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Coene, W., A. F. de Jong, D. van Dyck, G. van Tendeloo, and J. van Landuyt. "Digital image processing for high resolution electron microscopy." Physica Status Solidi (a) 107, no. 2 (June 16, 1988): 521–30. http://dx.doi.org/10.1002/pssa.2211070207.

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Bostanjoglo, Oleg, and Jochen Kornitzky. "Nanoseconds Double-Frame and Streak Transmission Electron Microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 180–81. http://dx.doi.org/10.1017/s0424820100179658.

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Material processing and synthesis is increasingly done by lasers. In order to apply this modern tool effectively, the laser-induced physical processes must be well known. As transmission electron microscopy is a powerful method to study the structure of the treated material, it seemed worthwhile to extend this technique for fast phase transitions, as are triggered by laser radiation. High-speed TEM may be realized either by pulsing the detector /l/ or the illuminating electron beam. The latter technique is more convenient and is described here.Fig. 1 shows a high-speed TEM designed for taking either double frame images (exposure/ repetition times ≿ 10 ns/≿ 50 ns) or streak images of transitions induced by a laser in the thin film specimen. It consists of a modified commercial TEM, an attached Q-switched (FWHM 50 ns), frequency-doubled (532 nm) Nd:YAG laser for treating the specimen, and electronics for electron beam pulsing and image storage. The TEM is equipped with focusing/deflecting optics for the laser radiation, an electron beam pulser generating either the exposure times for double frame pictures or the streak, and an image shifter. The image detector is a proximity focusing double stage MicroChannel Plate (MCP)/scintillator assembly. A CCD camera transfers the image to a PC-backed digitizing and frame grabbing card. The components are synchronized by a specially designed logic unit /2/.

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Jeng, T. W., R. A. Crowther, G. Stubbs, and W. Chiu. "Alpha Helices of TMV Visualized by Cryo-Electron Microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 154–55. http://dx.doi.org/10.1017/s0424820100102857.

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Tobacco mosaic virus (TMV) is a helical particle, the structure of which has been determined by X-ray diffraction. We chose it as a test specimen to investigate whether cryo-electron microscopy and computer image processing could reveal internal structure at high resolution in a non-crystalline specimen.Low dose images of TMV embedded in a thin layer of vitreous ice were recorded at 60,000 magnification in a JEOL100CX electron microscope equipped with a cold stacje at -148°C. The best images were selected for processing on the basis of their optical diffractograms. The defocus was determined from the image of the carbon film adjacent to the hole over which TMV particles were suspended. The defocus values of processed images ranged from 5000 to -10000 Å. The initial processing steps included masking out the selected segment of a particle, interpolating the image to make the axis of a selected particle segment parallel to the transform array, straightening the particle segment by a real space correlation and re-interpolation procedure. The computed structure factors from the straightened particle segment were corrected for the effects of defocus by applying a Wiener filter function.

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Inoué, Shinya. "Digitally Enhanced, Polarization-Based Microscopy: Reality and Dreams." Microscopy and Microanalysis 7, S2 (August 2001): 2–3. http://dx.doi.org/10.1017/s1431927600026088.

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Polarized light microscopy is used to identify and image optically anisotropic regions of the specimen; to determine their optical character; and to explore the arrangement of the molecules, fine structure, or atomic lattices that are responsible for the anisotropy. These studies can be carried out non-destructively in real time, and reveal events or structures that lie far below the resolution limit of the light microscope, or indeed at times even the electron microscope.In biology, to study the dynamically changing, minute and weakly anisotropic domains within living cells, the polarizing microscope must be able to detect and measure birefringence retardances to a fraction of a nm, record the image with high microscopic resolution at nearvideo rate, and do so while the cell remains active.Over the years, the extinction property and imaging capability of the basic polarizing microscope have been substantially improved by advances in optical design. More recently, video and CCD imaging and digital electronic processing have further enhanced the quality of the polarizing microscope image and our ability to rapidly detect and measure weak anisotropy.

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Ishii, Shin, Sehyung Lee, Hidetoshi Urakubo, Hideaki Kume, and Haruo Kasai. "Generative and discriminative model-based approaches to microscopic image restoration and segmentation." Microscopy 69, no. 2 (March 26, 2020): 79–91. http://dx.doi.org/10.1093/jmicro/dfaa007.

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Abstract Image processing is one of the most important applications of recent machine learning (ML) technologies. Convolutional neural networks (CNNs), a popular deep learning-based ML architecture, have been developed for image processing applications. However, the application of ML to microscopic images is limited as microscopic images are often 3D/4D, that is, the image sizes can be very large, and the images may suffer from serious noise generated due to optics. In this review, three types of feature reconstruction applications to microscopic images are discussed, which fully utilize the recent advancements in ML technologies. First, multi-frame super-resolution is introduced, based on the formulation of statistical generative model-based techniques such as Bayesian inference. Second, data-driven image restoration is introduced, based on supervised discriminative model-based ML technique. In this application, CNNs are demonstrated to exhibit preferable restoration performance. Third, image segmentation based on data-driven CNNs is introduced. Image segmentation has become immensely popular in object segmentation based on electron microscopy (EM); therefore, we focus on EM image processing.

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Herman, Gabor T., Roberto Marabini, Jos�-Mar�a Carazo, Edgar Gardu�o, Robert M. Lewitt, and Samuel Matej. "Image processing approaches to biological three-dimensional electron microscopy." International Journal of Imaging Systems and Technology 11, no. 1 (2000): 12–29. http://dx.doi.org/10.1002/(sici)1098-1098(2000)11:1<12::aid-ima3>3.0.co;2-n.

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Rees, Eric J., Miklos Erdelyi, Gabriele S. Kaminski Schierle, Alex Knight, and Clemens F. Kaminski. "Elements of image processing in localization microscopy." Journal of Optics 15, no. 9 (September 1, 2013): 094012. http://dx.doi.org/10.1088/2040-8978/15/9/094012.

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Wei, D. H., Y. J. Hsu, R. Klauser, I. H. Hong, G. C. Yin, and T. J. Chuang. "Photoelectron Microscopy Projects at SRRC." Surface Review and Letters 10, no. 04 (August 2003): 617–24. http://dx.doi.org/10.1142/s0218625x0300544x.

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The combination of traditional surface-spectroscopic methods and microscopic imaging techniques is gaining popularity along with the advances of nanotechnology. Among the available techniques, scanning photoelectron microscopy (SPEM) and photoelectron emission microscopy (PEEM) are two methods recently developed at the Synchrotron Radiation Research Center (SRRC). The SPEM station uses a Fresnel zone-plate optics to focus the soft X-ray beam and form a microprobe. Photoelectrons emitted from the illuminated spot are used to perform micro-photoelectron spectroscopy (μ-PES) measurements or to image the sample. The PEEM station, on the other hand, collects secondary electrons emitted from the sample upon photon irradiation, and uses an all-electrostatic column to magnify the field of view defined by the objective lens. By stepping the photon energy, micro-X-ray absorption spectra (μ-XAS) can be extracted from a sequence of images after proper image processing.

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Meschini, Stefania. "Correlative Microscopy in Life and Materials Sciences." European Journal of Histochemistry 61, s4 (November 2, 2017): 1. http://dx.doi.org/10.4081/ejh.2017.2864.

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<p class="p1">The conference aims to update participants on innovative microscopic equipment which, by correlating the various features of optical and electron microscopy, can maximize the potential applications of morphological and ultrastructural methods. The conference will address the limits of sample preparation, the optimization of image processing, and the critical analysis of experimental results with different materials.</p>

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Rez, Peter, and W. J. de Ruijter. "The Electron Microscope and the Computer: Present Trends and Future Prospects." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 116–17. http://dx.doi.org/10.1017/s0424820100179336.

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In the present generation of electron microscopes the roles of computers or microprocessors can be divided into control, acquisition and analysis of both spectral and image data. Not much, however, has been done to realise the full power of computer based systems and integrate all these functions with the electron optics. The control of practically all microscope columns is performed by an 8-bit or 16-bit processor usually running a program that repeatedly scans for user inputs and changes lens currents or alignment settings if necessary. External control for special experiments can either be implemented by scanning an additional user input from a serial port or by allowing external analog signals to replace those generated by the microscope control scheme. As the program loop typically takes 0.1 sec to complete it is preferable to implement some functions such as external beam scanning by providing analog ramps (even if generated by another computer).Computer acquistion of data was introduced to electron microscopy with analytical techniques, such as EDX, in which the computer was the basis of a multi channel analyser. In the case of energy loss and Auger spectroscopy, computer scanning of the spectrometer and acquisition of single electron pulse-counted data quickly displaced chart recorders as a means of collecting data. A computer based system not only could perform acquisition more efficiently, it could also provide a convenient means for processing the results and doing quantitative analysis. Furthermore digitally stored data could easily be transferred to other systems on disks or by direct link (such as ethernet) and analysed elsewhere. However for image acquisition there has been very little use of computers in acquiring data. Although microscopists are happy to consider a spectrum as an array of numbers they still prefer to deal with images as pictures rather than digital data sets. The problems are not entirely psychological since a major barrier to the widespread use of image processing in microscopy is the lack of a suitable detection system. TV cameras compare unfavourably with photographic plates in terms of both dynamic range and "resolution" as defined loosely in terms of pixel size or lines/mm. This argument does not apply to scanning microscopes but, even in scanning systems, frame buffers and powerful computer systems have only been integrated as part of the microscope electronics in the last few years. Microscopists still prefer to measure quantities from exposed photographs rather than work with digitized data in a workstation environment using high level image processing software. Until recently cost may have been a consideration but now computing platforms of sufficient capability are less than 1/5 of the cost of an average SEM.

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Rickard, William D. A., Jéssica Fernanda Ramos Coelho, Joshua Hollick, Susannah Soon, and Andrew Woods. "Application of Photogrammetric 3D Reconstruction to Scanning Electron Microscopy: Considerations for Volume Analysis." Electronic Imaging 2021, no. 18 (January 18, 2021): 60404–1. http://dx.doi.org/10.2352/issn.2470-1173.2021.18.3dia-102.

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Photogrammetric three-dimensional (3D) reconstruction is an image processing technique used to develop digital 3D models from a series of two-dimensional images. This technique is commonly applied to optical photography though it can also be applied to microscopic imaging techniques such as scanning electron microscopy (SEM). The authors propose a method for the application of photogrammetry techniques to SEM micrographs in order to develop 3D models suitable for volumetric analysis. SEM operating parameters for image acquisition are explored and the relative effects discussed. This study considered a variety of microscopic samples, differing in size, geometry and composition, and found that optimal operating parameters vary with sample geometry. Evaluation of reconstructed 3D models suggests that the quality of the models strongly determines the accuracy of the volumetric measurements obtainable. In particular, they report on volumetric results achieved from a laser ablation pit and discuss considerations for data acquisition routines.

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Oho, Eisaku, Kazuhiko Suzuki, and Sadao Yamazaki. "Applying Fast Scanning Method Coupled with Digital Image Processing Technology as Standard Acquisition Mode for Scanning Electron Microscopy." Scanning 2020 (March 31, 2020): 1–9. http://dx.doi.org/10.1155/2020/4979431.

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This study proposes an efficient and fast method of scanning (e.g., television (TV) scan) coupled with digital image processing technology to replace the conventional slow-scan mode as a standard model of acquisition for general-purpose scanning electron microscopy (SEM). SEM images obtained using the proposed method had the same quality in terms of sharpness and noise as slow-scan images, and it was able to suppress the adverse effects of charging in a full-vacuum condition, which is a challenging problem in this area. Two problems needed to be solved in designing the proposed method. One was suitable compensation in image quality using the inverse filter based on characteristics of the frequency of a TV-scan image, and the other to devise an accurate technique of image integration (noise suppression), the position alignment of which is robust against noise. This involved using the image montage technique and estimating the number of images needed for the integration. The final result of our TV-scan mode was compared with the slow-scan image as well as the conventional TV-scan image.

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Zuo, J. M. "Image Restoration and Characteristics of Slow_Scan CCD Camera and Imaging Plates." Microscopy and Microanalysis 3, S2 (August 1997): 1091–92. http://dx.doi.org/10.1017/s1431927600012344.

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The performance of slow scan CCD (SSC) camera [1,2] and imaging plate (IP) [3] for digital recording is limited by resolution and noise. The SSC camera and IP are two digital detectors currently available for transmission electron microscope (TEM). Imaging plates are re-usable flexible sheets, which are used in the standard cassettes. They are readout digitally with a 25 μm pixel size. Both detectors are linear and have large dynamic range. The SSC is a fixed accessory of TEM, images can be acquired, processed and viewed immediately by the microscope operator. The IP fits into a regular film cassette and is used like film except for the processing method. The image plate records electron image by storing electron energy in the potential well of defect states in a photo-stimulable phosphor. The stored image is read out by scanning a laser probe and detecting the stimulated luminescence in a reader. The SSC uses scintillator to convert electrons to photons and detects photons with CCD through optical couplings. The IP has 3000X3760 pixels. The available SSC for electron microscopy ranges from 512×512 to 2048×2048 pixels.

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TURNER, JAMES A. "Digital imaging of micro bivalves." Zoosymposia 1 (July 25, 2008): 47–61. http://dx.doi.org/10.11646/zoosymposia.1.1.7.

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Advancements in digital camera technology, microscope optics and image capture software have allowed researchers to create more detailed and higher quality images than ever before. Digital imaging using light microscopy at high magnifi - cations does, however, have its limitations. Features that may be diagnostic for species identifi cation can often be diffi cult to illustrate using standard imaging techniques alone, and other methods, such as Scanning Electron Microscopy (SEM) and traditional line illustration, may be better suited to the task. The best results are often achieved by using a combination of these methods to create visual taxonomic guides to bivalve species. Drawing from the experiences gained whilst undertaking digital imaging projects, this paper covers current working practices in place at Amgueddfa Cymru - National Museum Wales, providing details of the equipment and techniques in use. Specimen preparation, lighting methods, digital image post-processing and image fi le management are discussed. These topics will detail the methods used for capturing aspects of bivalve morphology of both the shell and the anatomy of specimens 5 mm in size or less in order to produce publication quality images for taxonomic research.

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Hovmöller, Sven, Xiaodong Zou, Da Neng Wang, Jose Maria González-Calbet, and Maria Vallet-Regí. "Structure determination of Ca4Fe2Ti2O11 by electron microscopy and crystallographic image processing." Journal of Solid State Chemistry 77, no. 2 (December 1988): 316–21. http://dx.doi.org/10.1016/0022-4596(88)90254-x.

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Crowther, R. A. "Viruses and the development of quantitative biological electron microscopy." Notes and Records of the Royal Society of London 58, no. 1 (January 22, 2004): 65–81. http://dx.doi.org/10.1098/rsnr.2003.0225.

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The electron microscope has become an important tool for determining the structure of biological materials of all kinds. Many technical advances in specimen preparation and in sophisticated methods of image analysis, initially based on optical systems but latterly on computer processing, have contributed to the development of the subject. Viruses of various kinds have often provided a convenient and appropriate test specimen. This paper describes the major technical advances and shows how viruses have had an important role in most of the developments.

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Hasegawa, S., T. Kawasaki, J. Endo, M. Futamoto, and A. Tonomura. "Digital phase analysis in interference electron microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 842–43. http://dx.doi.org/10.1017/s0424820100106272.

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Interference electron microscopy enables us to record the phase distribution of an electron wave on a hologram. The distribution is visualized as a fringe pattern in a micrograph by optical reconstruction. The phase is affected by electromagnetic potentials; scalar and vector potentials. Therefore, the electric and magnetic field can be reduced from the recorded phase. This study analyzes a leakage magnetic field from CoCr perpendicular magnetic recording media. Since one contour fringe interval corresponds to a magnetic flux of Φo(=h/e=4x10-15Wb), we can quantitatively measure the field by counting the number of finges. Moreover, by using phase-difference amplification techniques, the sensitivity for magnetic field detection can be improved by a factor of 30, which allows the drawing of a Φo/30 fringe. This sensitivity, however, is insufficient for quantitative analysis of very weak magnetic fields such as high-density magnetic recordings. For this reason we have adopted “fringe scanning interferometry” using digital image processing techniques at the optical reconstruction stage. This method enables us to obtain subfringe information recorded in the interference pattern.

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Santa, Nestor, Cigdem Keles, J. R. Saylor, and Emily Sarver. "Demonstration of Optical Microscopy and Image Processing to Classify Respirable Coal Mine Dust Particles." Minerals 11, no. 8 (August 2, 2021): 838. http://dx.doi.org/10.3390/min11080838.

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Respirable coal mine dust represents a serious health hazard for miners. Monitoring methods are needed that enable fractionation of dust into its primary components, and that do so in real time. Near the production face, a simple capability to monitor the coal versus mineral dust fractions would be highly valuable for tracking changes in dust sources—and supporting timely responses in terms of dust controls or other interventions to reduce exposures. In this work, the premise of dust monitoring with polarized light microscopy was explored. Using images of coal and representative mineral particles (kaolinite, crystalline silica, and limestone rock dust), a model was built to exploit birefringence of the mineral particles and effectively separate them from the coal. The model showed >95% accuracy on a test dataset with known particles. For composite samples containing both coal and minerals, the model also showed a very good agreement with results from the scanning electron microscopy classification, which was used as a reference method. Results could further the concept of a “cell phone microscope” type monitor for semi-continuous measurements in coal mines.

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Lee, R. J., and J. S. Walker. "Applications of CCEM to Environmental Health Problems." Proceedings, annual meeting, Electron Microscopy Society of America 43 (August 1985): 102–3. http://dx.doi.org/10.1017/s0424820100117558.

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Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.

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Yajima, Y., and Y. Takahashi. "Lorentz And Interference Electron Microscopy On A Scanning Tem." Microscopy and Microanalysis 5, S2 (August 1999): 38–39. http://dx.doi.org/10.1017/s1431927600013519.

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Magnetic imaging can be performed both on conventional (projection) and scanning TEM (CTEM/STEM). The CTEM-based magnetic imaging, classified into Fresnel, Foucault, holography, and other modes, has proven successful by now in observing various magnetic objects, and has accordingly been well documented elsewhere. The STEMbased one has emerged relatively recently prompted by the rapid growth of current STEM technology.The most ubiquitous implementation of Lorentz microscopy on a STEM is the differential phase contrast (DPC) mode. Each scanning signal obtained in the DPC mode is linear to Lorentz deflection, thus reflects the magnitude of an in-plane component of magnetic induction integrated along the optical axis(Fig.l). The signals therefore suffice to generate integrated in-plane magnetic induction maps(Fig.2). Furthermore, by making use of the fact that the Lorentz deflection distribution across the image plane forms an irrotational (vortex-free) 2D vector field, a pertinent numerical image processing yields a function equivalent to the electron phase function representing magnetically distorted electron wavefront.

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Ball, Alexander D., Tomasz Goral, and Seyit A. Kamanli. "CONFOCAL MICROSCOPY APPLIED TO PALEONTOLOGICAL SPECIMENS." Paleontological Society Papers 22 (September 2016): 39–55. http://dx.doi.org/10.1017/scs.2017.7.

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AbstractConfocal laser scanning microscopy is a well-established optical technique allowing for three-dimensional (3-D) visualization of fluorescent specimens with a resolution close to the diffraction limit of light. Thanks to the availability of a wide range of fluorescent dyes and selective staining using antibodies, the technique is commonly used in life sciences as a powerful tool for studying different biological processes, often at the level of single molecules. However, this type of approach is often not applicable for specimens that are preserved in historical slide collections, embedded in amber, or are fossilized, and cannot be exposed to any form of selective staining or other form of destructive treatment. This usually narrows the number of microscopic techniques that can be used to study such specimens to traditional light microscopy or scanning electron microscopy. However, these techniques have their own limitations and cannot fully reveal 3-D structures within such barely accessible samples. Can confocal microscopy be of any help? The answer is positive, and it is due to the fact that many paleontological specimens exhibit a strong inherent autofluorescence that can serve as an excellent source of emitted photons for confocal microscopy visualizations either through reconstruction of the induced autoflourescent signal from the sample, or through reconstruction of the reflected signal from the sample surface. Here, we describe the workflow and methodology involved in acquiring confocal data from a sample and reprocessing the resulting image stack using the image-processing program imageJ before reconstructing the data using the open-source 3-D rendering program, Drishti. This approach opens new possibilities for using confocal microscopy in a nondestructive manner for visualizing complex paleontological material that has never previously been considered as suitable for this type of microscopic technique.

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Vulovic, M., B. Rieger, L. J. van Vliet, A. J. Koster, and R. B. G. Ravelli. "A toolkit for the characterization of CCD cameras for transmission electron microscopy." Acta Crystallographica Section D Biological Crystallography 66, no. 1 (December 21, 2009): 97–109. http://dx.doi.org/10.1107/s0907444909031205.

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Charge-coupled devices (CCD) are nowadays commonly utilized in transmission electron microscopy (TEM) for applications in life sciences. Direct access to digitized images has revolutionized the use of electron microscopy, sparking developments such as automated collection of tomographic data, focal series, random conical tilt pairs and ultralarge single-particle data sets. Nevertheless, for ultrahigh-resolution work photographic plates are often still preferred. In the ideal case, the quality of the recorded image of a vitrified biological sample would solely be determined by the counting statistics of the limited electron dose the sample can withstand before beam-induced alterations dominate. Unfortunately, the image is degraded by the non-ideal point-spread function of the detector, as a result of a scintillator coupled by fibre optics to a CCD, and the addition of several inherent noise components. Different detector manufacturers provide different types of figures of merit when advertising the quality of their detector. It is hard for most laboratories to verify whether all of the anticipated specifications are met. In this report, a set of algorithms is presented to characterize on-axis slow-scan large-area CCD-based TEM detectors. These tools have been added to a publicly available image-processing toolbox forMATLAB. Three in-house CCD cameras were carefully characterized, yielding, among others, statistics for hot and bad pixels, the modulation transfer function, the conversion factor, the effective gain and the detective quantum efficiency. These statistics will aid data-collection strategy programs and provide prior information for quantitative imaging. The relative performance of the characterized detectors is discussed and a comparison is made with similar detectors that are used in the field of X-ray crystallography.

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Fan, G. Y., A. J. Gubbens, O. L. Krivanek, M. L. Leber, and P. E. Mooney. "Combining slow-scan CCD images to extend image size and dynamic range." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 524–25. http://dx.doi.org/10.1017/s0424820100086933.

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A slow-scan CCD (SSC) camera attached to an electron microscope can record images with 4096 gray levels, nonlinearity less than ±1 %, and a detective quantum efficiency (DQE) greater than 0.5 even with just one primary electron per pixel. Moreover, the images are read out by a computer and are therefore available for further processing as soon as they are acquired. SSC cameras therefore seem destined to replace photographic film as the primary recording medium used in electron microscopy as completely as they have in top-level optical astronomy, where film is now mostly of historical interest.However, the SSCs have two disadvantages compared to photographic film: 1) Fewer number of pixels and 2) the “spill” problem. Currently, SSCs are available for electron microscopists with a sensor array of up to 1024x1024 pixels. (2048x2048 CCD sensors have been developed but their price is high and performance, in terms of pixel defects, is low.) By comparison, a micrograph can record about 10,000x10,000 pixels. And, in order to maximize sensitivity, SSCs do not incorporate anti-blooming wells. As a result, a saturated pixel caused by, for example, a Bragg spot, will “spill” into neighboring pixels.

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Ransick, Mark H., and Chadwick D. Barklay. "Interfacing a Personal Computer to an Analog Scanning Electron Microscope for Storing Images on Optical Disks." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 2 (August 12, 1990): 84–85. http://dx.doi.org/10.1017/s0424820100134016.

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Most manufacturers of scanning electron microscopes (SEM) now offer models that display an image digitally. This holds many advantages, including the ability to store the image on a disk and perform image analysis on the sample. Most SEMs in service, however, produce only an analog video output; they do not have the ability to digitize the image. Film is the only method of storing images.Consequentially, film is a significant portion of every microscopy laboratory’s budget. Completely eliminating the use of film from use is not practical. There will always be the need to examine a hard copy of the image; many programs require duplicate copies of each image generated; and it is sound practice to keep a copy of each image on file. By archiving digital images to an inexpensive media, the amount of film used or the time devoted to processing negatives can be greatly reduced.By using personal computers (PCs)s, with a digitizing board and analog to digital (A/D) board, it is possible to construct a relatively low cost digitizing system for any SEM.

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Chiu, W., M. F. Schmid, and T. W. Jeng. "Computer processing of high-resolution images of periodic specimens." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 2–5. http://dx.doi.org/10.1017/s0424820100141834.

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Cryo-electron microscopy has been developed to the point where one can image thin protein crystals to 3.5 Å resolution. In our study of the crotoxin complex crystal, we can confirm this structural resolution from optical diffractograms of the low dose images. To retrieve high resolution phases from images, we have to include as many unit cells as possible in order to detect the weak signals in the Fourier transforms of the image. Hayward and Stroud proposed to superimpose multiple image areas by combining phase probability distribution functions for each reflection. The reliability of their phase determination was evaluated in terms of a crystallographic “figure of merit”. Grant and co-workers used a different procedure to enhance the signals from multiple image areas by vector summation of the complex structure factors in reciprocal space.

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Ptashekas, J. "Application of video EM and image processing for evaluation of barrier tissues endocrine activity after environmental chemical exposure." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 3 (August 12, 1990): 963. http://dx.doi.org/10.1017/s0424820100162405.

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Biotesting procedure of new environmental chemicals is unavoidable within framework of environmental medicine and public health. Micrographs in transmission electron microscopy are indispensable for evaluation of fine details of ultrastructure of diffuse endocrine system cells located in barrier epithelial tissues of gastrointestinal tract. At the same time it is insufficient to obtain integrated image and tissue functional activity analysis. Videoprocessed electron microscopy provides for full section (s) visual information and is applicable in environmental medicine.Wistar rats 250-280 gr b.w. had been once tube fed with 0.1 DL50 solution of piperasin derivative herbicide saprol (Celamerck, FRG) and investigated 15 min., 4 h and 24 h after treatment. Vertical samples of pyloric mucosa were prepared for transmission electron microscopy (TEM). Separate types of gastric endocrine cells had been verified ultrastructurally from micrographs according to lausanne (1981) Enteroendocrine Cells Classification. TEM image had been videoprojected to the monitor and computer processed to obtain distinct electron optical density, maturity level and number of secretory granules within 1 sq mkm of endocrine cell cytoplasma. Granules size (nm) frequency distribution histograms provided as well.

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Peters, Klaus-Ruediger. "Collection deficiencies of scanning electron microscopy signal contrasts measured and corrected by differential hysteresis image processing." Scanning 18, no. 8 (December 18, 2006): 539–55. http://dx.doi.org/10.1002/sca.4950180803.

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Toth, P., J. K. Farrer, A. B. Palotas, J. S. Lighty, and E. G. Eddings. "Automated analysis of heterogeneous carbon nanostructures by high-resolution electron microscopy and on-line image processing." Ultramicroscopy 129 (June 2013): 53–62. http://dx.doi.org/10.1016/j.ultramic.2013.02.017.

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Pietroy, David, Issam Gereige, and Cécile Gourgon. "Automatic detection of NIL defects using microscopy and image processing." Microelectronic Engineering 112 (December 2013): 163–67. http://dx.doi.org/10.1016/j.mee.2013.03.126.

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Koster, A. J., D. Typke, and M. J. C. de Jong. "Fast and Accurate Autotuning of a TEM for High-Resolution and Low Dose Electron Microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 114–15. http://dx.doi.org/10.1017/s0424820100179324.

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The application of transmission electron microscopy (TEM) for the research on biological and inorganic structures is restricted by the radiation sensitivity of the specimens and the deviations from the optimal setting of the TEM parameters. The three most important optical parameters that require extensive fine tuning are the defocus, astigmatism and beam tilt misalignment. Autotuning, i.e. automatic optimization of these three parameters, can help to optimize microscope settings using a minimum amount of electron irradiation.Until recently, the practical applications of the autotuning methods proposed in literature were limited due to insufficient computational power and the lack of commercially available computer interfaces to TEM. These instrumental limitations can now be overcome be a fully remote controllable TEM, a highly sensitive video camera system, and a fast image processing system.

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Andrews, S. B., N. B. Pivovarova, J. Hongpaisan, and R. D. Leapman. "High-Resolution Analysis of Rapidly Frozen Biological Specimens: Capabilities and Limitations." Microscopy and Microanalysis 5, S2 (August 1999): 412–13. http://dx.doi.org/10.1017/s1431927600015385.

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The past decade has seen major advances in the analytical capability and utility of both fixed beam and scanning beam electron microscopes. In particular, scanning transmission electron microscopy (STEM) and energy-filtering transmission microscopy (EFTEM) have benefited from the development of devices and techniques—including improved electron optics, sensitive solid-state detectors and new software for imaging and electron energy loss spectroscopy (EELS)—that optimize detection of weak spectroscopic signals arising from biological specimens while minimizing specimen damage. Here we discuss and illustrate some of these advances, especially in the context of structural imaging, detection limits and mapping techniques for the biologically important elements phosphorus and calcium. Analytical microscopy of biological tissues is absolutely dependent on cryotechniques. It is generally agreed that rapid freezing and subsequent low-temperature processing, e.g., cryosectioning or direct cryotransfer of frozen-hydrated specimens, is the most reliable way to preserve the native distribution and organization of biological structures. Equally important, however, as an adjunct to spectroscopic analysis is the use of established low-temperature, low-dose techniques for recording optimized images. By limiting beam exposure, low-dose methods greatly improve the quality of images from fragile, freeze-dried preparations. In this case, the quality and information content of, e.g., cryosections are virtually as good as conventional preparations (Fig 1).

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Ott, Tobias, Diego Roldán, Claudia Redenbach, Katja Schladitz, Michael Godehardt, and Sören Höhn. "Three-dimensional structural comparison of tantalum glancing angle deposition thin films by FIB-SEM." Journal of Sensors and Sensor Systems 8, no. 2 (October 30, 2019): 305–15. http://dx.doi.org/10.5194/jsss-8-305-2019.

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Abstract. Thin tantalum films generated by glancing angle deposition serve as functional optical layers, for instance as absorption layers for ultrathin infrared sensors. They consist of nano-rods whose dimensions and distribution influence the optical properties of the thin film. Serial sectioning by a focused ion beam combined with scanning electron microscopy of the slices generates stacks of highly resolved images of this nanostructure. Dedicated image processing reconstructs the spatial structure from this stack such that 3-D image analysis yields geometric information that can be related to the optical performance.

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Kennedy, S. K., D. Barton, H. P. Lentz, J. Newlin, P. M. Sauter, and F. C. Schwerer. "Montages and Virtual Reality - A Paradim for Presentation of Analytical Data." Microscopy and Microanalysis 4, S2 (July 1998): 66–67. http://dx.doi.org/10.1017/s1431927600020456.

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Micro-graphs acquired using optical or electron microscopes reveal information on a local scale. When a sample is not homogeneous at the scale of the image, it may be necessary to view the sample at a magnification lower than that available by the instrument. Montages of micro-graphs can be constructed through the following steps: acquisition of individual images, stitching individual images into a single image (a montage), and producing the final exhibit(s). Performing these steps has traditionally required careful stage and illumination control during acquisition, dodging during printing, and hours with scissors and glue-pot during paste-up. Because this procedure is labor intensive, the creation of montages was limited to only the most important or critical situations. Digital microscopy, image processing software, and Web-enabled multi-media applications have reduced the barriers for creation of montages and provided for new display modes, thereby stimulating a revival of the use of montages as an enhanced presentation mode for technical data.

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Cowger, Win, Andrew Gray, Silke H. Christiansen, Hannah DeFrond, Ashok D. Deshpande, Ludovic Hemabessiere, Eunah Lee, et al. "Critical Review of Processing and Classification Techniques for Images and Spectra in Microplastic Research." Applied Spectroscopy 74, no. 9 (September 2020): 989–1010. http://dx.doi.org/10.1177/0003702820929064.

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Microplastic research is a rapidly developing field, with urgent needs for high throughput and automated analysis techniques. We conducted a review covering image analysis from optical microscopy, scanning electron microscopy, fluorescence microscopy, and spectral analysis from Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, pyrolysis gas–chromatography mass–spectrometry, and energy dispersive X-ray spectroscopy. These techniques were commonly used to collect, process, and interpret data from microplastic samples. This review outlined and critiques current approaches for analysis steps in image processing (color, thresholding, particle quantification), spectral processing (background and baseline subtraction, smoothing and noise reduction, data transformation), image classification (reference libraries, morphology, color, and fluorescence intensity), and spectral classification (reference libraries, matching procedures, and best practices for developing in-house reference tools). We highlighted opportunities to advance microplastic data analysis and interpretation by (i) quantifying colors, shapes, sizes, and surface topologies with image analysis software, (ii) identifying threshold values of particle characteristics in images that distinguish plastic particles from other particles, (iii) advancing spectral processing and classification routines, (iv) creating and sharing robust spectral libraries, (v) conducting double blind and negative controls, (vi) sharing raw data and analysis code, and (vii) leveraging readily available data to develop machine learning classification models. We identified analytical needs that we could fill and developed supplementary information for a reference library of plastic images and spectra, a tutorial for basic image analysis, and a code to download images from peer reviewed literature. Our major findings were that research on microplastics was progressing toward the use of multiple analytical methods and increasingly incorporating chemical classification. We suggest that new and repurposed methods need to be developed for high throughput screening using a diversity of approaches and highlight machine learning as one potential avenue toward this capability.

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Pope, Kenneth J., Jason L. P. Smith, and Joe G. Shapter. "Imaging molecular adsorbates using scanning tunnelling microscopy and image processing." Smart Materials and Structures 11, no. 5 (September 13, 2002): 679–85. http://dx.doi.org/10.1088/0964-1726/11/5/309.

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Duque, D., J. Garzón, and T. Gharbi. "A study of dispersion in chromatic confocal microscopy using digital image processing." Optics & Laser Technology 131 (November 2020): 106414. http://dx.doi.org/10.1016/j.optlastec.2020.106414.

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MacRae, Colin, Nick Wilson, and Mark Pownceby. "Electron Microprobe Mapping as a Tool in Ilmenite Characterisation." Microscopy and Microanalysis 7, S2 (August 2001): 710–11. http://dx.doi.org/10.1017/s1431927600029627.

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The demand for accurate mineralogical data is increasing rapidly as exploration methods, prospect evaluation procedures and metallurgical optimisation studies become more sophisticated. in response to these needs, semi-automated and automated image processing systems which detect minerals using optical microscopy, scanning electron microscopy or electron microprobe microanalysis (EPMA) are becoming increasingly important tools in the exploration, mining and mineral processing industries. CSIRO Minerals has developed an EPMA based imaging (or mapping) method for characterising ilmenite concentrates. The method uses a JEOL 8900R EPMA to collect elemental x-ray maps which are then processed using in-house developed software, Chimage. The mapping procedure differs from traditional automated identification systems in that no detailed a priori knowledge of the mineral phases is required. in addition, Chimage software enables complete processing and interpretation of the data set off-line. Elemental data can be displayed in either scatter or ternary diagrams showing clusters which allow mineral phases to be identified.

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Dyachenko, A. A., and V. P. Ryabukho. "Color models of interference images of thin stratified objects in optical microscopy." Computer Optics 43, no. 6 (December 2019): 956–67. http://dx.doi.org/10.18287/2412-6179-2019-43-6-956-967.

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Algorithms for the analysis of polychromatic interference patterns in images of thin stratified objects in optical microscopy are considered. The algorithms allow one to measure the thin-film optical thickness. A measurement method based on the comparison of colors of the interference image under study and a numerically simulated image is discussed. We discuss a mathematical model for the calculation and numerical simulation of interference patterns and algorithms for interference pattern processing. Color comparison in an RGB color model is described and limitations of such a method are shown. The feasibility of using a Lab color model is shown and algorithms of interference color comparison in this model are presented. Results of application of the presented algorithms to measuring the optical thickness of red blood cells in a blood smear are discussed. The estimation of the error and robustness of the proposed algorithms is conducted.

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Allais, M., and M. Gandais. "Structural study of Cd(S,Se) doped glasses. High-resolution transmission electron microscopy (HRTEM) assisted by image processing." Journal of Applied Crystallography 23, no. 5 (October 1, 1990): 418–23. http://dx.doi.org/10.1107/s0021889890006379.

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High-resolution transmission electron microscopy (HRTEM) was used for examining Cd(S,Se) nanocrystals grown in silicate glasses commercially available as optical filters. The lattice images of the nanocrystals were numerated and submitted to filtering through Fourier transformation in order to sweep off the background signal originating mainly from glass. Optical filters from several firms were examined. The nanocrystals have been identified with Cd(S,Se) compounds crystallized in the wurzite structure, as in bulk material. The lattice images indicate crystallites having the shape of hexagonal prisms a little elongated along the c axis. The distribution of grain size differs according to the filter: the smallest size being about 1.5 nm (threshold for detection), the largest size varies from 7 to 10 nm, the average size sa , from 3–4 to 5–6 nm and the characteristic size sc from 5–6 to 7–8 nm (sc is the size of grains occupying the main part of the crystallized volume).

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Lakhdari, M. A., F. Krajcarz, J. D. Mithieux, H. P. Van Landeghem, and M. Veron. "Strength Enhancement of Superduplex Stainless Steel Using Thermomechanical Processing." Metals 11, no. 7 (July 9, 2021): 1094. http://dx.doi.org/10.3390/met11071094.

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The impact of microstructure evolution on mechanical properties in superduplex stainless steel UNS S32750 (EN 1.4410) was investigated. To this end, different thermomechanical treatments were carried out in order to obtain clearly distinct duplex microstructures. Optical microscopy and scanning electron microscopy, together with texture measurements, were used to characterize the morphology and the preferred orientations of ferrite and austenite in all microstructures. Additionally, the mechanical properties were assessed by tensile tests with digital image correlation. Phase morphology was not found to significantly affect the mechanical properties and neither were phase volume fractions within 13% of the 50/50 ratio. Austenite texture was the same combined Goss/Brass texture regardless of thermomechanical processing, while ferrite texture was mainly described by α-fiber orientations. Ferrite texture and average phase spacing were found to have a notable effect on mechanical properties. One of the original microstructures of superduplex stainless steel obtained here shows a strength improvement by the order of 120 MPa over the industrial material.

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Kiely, Carol, Gary Greenberg, and Christopher J. Kiely. "A New Look at Lunar Soil Collected from the Sea of Tranquility during the Apollo 11 Mission." Microscopy and Microanalysis 17, no. 1 (November 19, 2010): 34–48. http://dx.doi.org/10.1017/s1431927610093979.

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AbstractComplementary state-of-the-art optical, scanning electron, and X-ray microscopy techniques have been used to study the morphology of Apollo 11 lunar soil particles (10084-47). The combination of innovative lighting geometries with image processing of a through focal series of images has allowed us to obtain a unique collection of high-resolution light micrographs of these fascinating particles. Scanning electron microscopy (SEM) stereo-pair imaging has been exploited to illustrate some of the unique morphological properties of lunar regolith. In addition, for the first time, X-ray micrographs with submicron resolution have been taken of individual particles using X-ray ultramicroscopy (XuM). This SEM-based technique lends itself readily to the imaging of pores, cracks, and inclusions and allows the internal structure of an entire particle to be viewed. Rotational SEM and XuM movies have also been constructed from a series of images collected at sequential angles through 360°. These offer a new and insightful view of these complex particles providing size, shape, and spatial information on many of their internal features.

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Nicolosi, Valeria. "Processing and characterisation of two-dimensional nanostructures." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C510. http://dx.doi.org/10.1107/s2053273314094893.

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Low-dimensional nanostructured materials such as organic and inorganic nanotubes, nanowires and platelets are potentially useful in a number of areas of nanoscience and nanotechnology due to their remarkable mechanical, electrical and thermal properties. However difficulties associated with their lack of processability have seriously hampered both. In the last few years dispersion and exfoliation methods have been developed and demonstrated to apply universally to 1D and 2D nanostructures of very diverse nature, offering a practical means of processing the nanostructures for a wide range of innovative technologies. Among the first materials to have benefitted most from these advances are carbon nanotubes [6] and more recently graphene. Recently this work has been extended to boron nitride and a wide range of two-dimensional transition metal chalcogenides. These are potentially important because they occur in >40 different types with a wide range of electronic properties, varying from metallic to semiconducting. To make real applications truly feasible, however, it is crucial to fully characterize the nanostructures on the atomic scale and correlate this information with their physical and chemical properties. Advances in aberration-corrected optics in electron microscopy have revolutionised the way to characterise nano-materials, opening new frontiers for materials science. With the recent advances in nanostructure processability, electron microscopes are now revealing the structure of the individual components of nanomaterials, atom by atom. Here we will present an overview of very different low-dimensional materials issues, showing what aberration-corrected electron microscopy can do to answer materials scientists' questions. Particular emphasis will be given to the investigation of hexagonal boron nitride (hBN), molybdenum disulfide (MoS2), and tungsten disulfide (WS2) and the study of their structure, defects, stacking sequence, vacancies and low-atomic number individual adatoms. The analyses of the h-BN data showed that majority of nanosheets retain bulk stacking. However several of the images displayed stacking different from the bulk. Similar, to 2D h-BN, images of MoS2 and WS2 have shown the stacking previously unobserved in the bulk. This novel stacking consists of Mo/W stacked on the top each other in the consecutive layers.

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Cai, Changjie, Tomoki Nishimura, Jooyeon Hwang, Xiao-Ming Hu, and Akio Kuroda. "Asbestos Detection with Fluorescence Microscopy Images and Deep Learning." Sensors 21, no. 13 (July 4, 2021): 4582. http://dx.doi.org/10.3390/s21134582.

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Fluorescent probes can be used to detect various types of asbestos (serpentine and amphibole groups); however, the fiber counting using our previously developed software was not accurate for samples with low fiber concentration. Machine learning-based techniques (e.g., deep learning) for image analysis, particularly Convolutional Neural Networks (CNN), have been widely applied to many areas. The objectives of this study were to (1) create a database of a wide-range asbestos concentration (0–50 fibers/liter) fluorescence microscopy (FM) images in the laboratory; and (2) determine the applicability of the state-of-the-art object detection CNN model, YOLOv4, to accurately detect asbestos. We captured the fluorescence microscopy images containing asbestos and labeled the individual asbestos in the images. We trained the YOLOv4 model with the labeled images using one GTX 1660 Ti Graphics Processing Unit (GPU). Our results demonstrated the exceptional capacity of the YOLOv4 model to learn the fluorescent asbestos morphologies. The mean average precision at a threshold of 0.5 (mAP@0.5) was 96.1% ± 0.4%, using the National Institute for Occupational Safety and Health (NIOSH) fiber counting Method 7400 as a reference method. Compared to our previous counting software (Intec/HU), the YOLOv4 achieved higher accuracy (0.997 vs. 0.979), particularly much higher precision (0.898 vs. 0.418), recall (0.898 vs. 0.780) and F-1 score (0.898 vs. 0.544). In addition, the YOLOv4 performed much better for low fiber concentration samples (<15 fibers/liter) compared to Intec/HU. Therefore, the FM method coupled with YOLOv4 is remarkable in detecting asbestos fibers and differentiating them from other non-asbestos particles.

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Müller, Mark, Ivo de Sena Oliveira, Sebastian Allner, Simone Ferstl, Pidassa Bidola, Korbinian Mechlem, Andreas Fehringer, et al. "Myoanatomy of the velvet worm leg revealed by laboratory-based nanofocus X-ray source tomography." Proceedings of the National Academy of Sciences 114, no. 47 (November 6, 2017): 12378–83. http://dx.doi.org/10.1073/pnas.1710742114.

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X-ray computed tomography (CT) is a powerful noninvasive technique for investigating the inner structure of objects and organisms. However, the resolution of laboratory CT systems is typically limited to the micrometer range. In this paper, we present a table-top nanoCT system in conjunction with standard processing tools that is able to routinely reach resolutions down to 100 nm without using X-ray optics. We demonstrate its potential for biological investigations by imaging a walking appendage of Euperipatoides rowelli, a representative of Onychophora—an invertebrate group pivotal for understanding animal evolution. Comparative analyses proved that the nanoCT can depict the external morphology of the limb with an image quality similar to scanning electron microscopy, while simultaneously visualizing internal muscular structures at higher resolutions than confocal laser scanning microscopy. The obtained nanoCT data revealed hitherto unknown aspects of the onychophoran limb musculature, enabling the 3D reconstruction of individual muscle fibers, which was previously impossible using any laboratory-based imaging technique.

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Golijanin, Danilo. "An application of photoemission microscopy to failure analysis of complex silicon integrated circuits." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1686–87. http://dx.doi.org/10.1017/s0424820100133060.

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Emission of visible light from forward and reverse biased silicon p-n junctions due to the radiative electron-hole recombination has been known since the mid-50s. The weak light emission was also seen from a silicon-dioxide dielectric in an integrated gate oxide capacitor formed between a polysilicon gate and an (n or p) well in an integrated circuit. The difference in carrier energies for each of these recombination mechanisms gives rise to a specific photon wavelength (energy) distribution in the visible range. All photoemitting events are characterized by a very low level light intensity due to the low quantum efficiency of about 10−5 - 10−4 photons per one electron-hole recombination.The first practical photoemission microscope was constructed by Khurana and Chiang. They took the advantage of the advances in night vision technology and used it for imaging the faint ("invisible") light coming from various silicon structures. A typical photoemission microscope consists of an x-y-z stage with the device holder, an optical microscope, a lightsensitive camera all set within a light-tight enclosure and a computer system for image acquisition and processing.

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Ruiz, J. E., S. Paciornik, L. D. Pinto, F. Ptak, M. P. Pires, and P. L. Souza. "Optimization of digital image processing to determine quantum dots’ height and density from atomic force microscopy." Ultramicroscopy 184 (January 2018): 234–41. http://dx.doi.org/10.1016/j.ultramic.2017.09.004.

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Journal articles on the topic 'Optics. Image processing. Microscopy Electron microscopy'

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