scholarly journals GEOMETRIC DISTORTION OF HISTORICAL IMAGES FOR 3D VISUALIZATION

2020 ◽  
Vol V-2-2020 ◽  
pp. 649-655
Author(s):  
E. Paiz-Reyes ◽  
M. Brédif ◽  
S. Christophe
Keyword(s):  
3D Visualization ◽  
Image Plane ◽  
Chromatic Aberration ◽  
Geometric Distortion ◽  
Depth Of Field ◽  
Mathematical Function ◽  
Field Variation ◽  
Image Domain ◽  
Original Photograph ◽  
3D Scene

Abstract. Archivists, historians and national mapping agencies, among others, are archiving large datasets of historical photographs. Nevertheless, the capturing devices used to acquire these images possessed a diversity of effects that influenced the quality of the final resulting picture, e.g. geometric distortion, chromatic aberration, depth of field variation, etc. This paper examines singularly the topic of geometric distortion for a co-visualization of historical photos within a 3D model of the photographed scene. A distortion function of an image is ordinarily estimated only on the image domain by adjusting its parameters to observations of point correspondences. This mathematical function may exhibit overfits, oscillations or may not be well defined outside of this domain. The contribution of this work is the description of a distortion model defined on the whole undistorted image plane. We extrapolate the distortion estimated only on the image domain and then transfer this distortion information to the view of the 3D scene. This enables to look at the scene through an estimated camera and zoom out to see the context around the original photograph with a well-defined and behaved distortion. These findings may be a significant addition to the overall purpose of creating innovative ways to examine and visualize old photographs.

Tandem scanning confocal light microscopy as compared with x-ray diffraction for characterizing the behavior of clays in fluid-saturated petroleum reservoir rock

1989 ◽  
Vol 47 ◽  
pp. 148-149
Author(s):  
C.J. Stuart ◽  
B.E. Viani ◽  
J. Walker ◽  
T.H. Levesque
Keyword(s):  
Light Microscopy ◽  
Image Plane ◽  
Reservoir Rock ◽  
Depth Of Field ◽  
Objective Lens ◽  
Scanning System ◽  
Light Sources ◽  
Petroleum Reservoir ◽  
Image Recording ◽  
Scan Speed

Many techniques of imaging used to characterize petroleum reservoir rocks are applied to dehydrated specimens. In order to directly study behavior of fines in reservoir rock at conditions similar to those found in-situ these materials need to be characterized in a fluid saturated state.Standard light microscopy can be used on wet specimens but depth of field and focus cannot be obtained; by using the Tandem Scanning Confocal Microscope (TSM) images can be produced from thin focused layers with high contrast and resolution. Optical sectioning and extended focus images are then produced with the microscope. The TSM uses reflected light, bulk specimens, and wet samples as opposed to thin section analysis used in standard light microscopy. The TSM also has additional advantages: the high scan speed, the ability to use a variety of light sources to produce real color images, and the simple, small size scanning system. The TSM has frame rates in excess of normal TV rates with many more lines of resolution. This is accomplished by incorporating a method of parallel image scanning and detection. The parallel scanning in the TSM is accomplished by means of multiple apertures in a disk which is positioned in the intermediate image plane of the objective lens. Thousands of apertures are distributed in an annulus, so that as the disk is spun, the specimen is illuminated simultaneously by a large number of scanning beams with uniform illumination. The high frame speeds greatly simplify the task of image recording since any of the normally used devices such as photographic cameras, normal or low light TV cameras, VCR or optical disks can be used without modification. Any frame store device compatible with a standard TV camera may be used to digitize TSM images.

Electron Holography Improving Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 208-209
Author(s):  
Hannes Lichte
Keyword(s):  
Electron Microscopy ◽  
Transfer Functions ◽  
Imaging System ◽  
Spherical Aberration ◽  
Image Plane ◽  
Chromatic Aberration ◽  
Object Wave ◽  
Objective Lens ◽  
Electron Holography ◽  
Wave Aberration

Generally, the electron object wave o(r) is modulated both in amplitude and phase. In the image plane of an ideal imaging system we would expect to find an image wave b(r) that is modulated in exactly the same way, i. e. b(r) =o(r). If, however, there are aberrations, the image wave instead reads as b(r) =o(r) * FT(WTF) i. e. the convolution of the object wave with the Fourier transform of the wave transfer function WTF . Taking into account chromatic aberration, illumination divergence and the wave aberration of the objective lens, one finds WTF(R) = Echrom(R)Ediv(R).exp(iX(R)) . The envelope functions Echrom(R) and Ediv(R) damp the image wave, whereas the effect of the wave aberration X(R) is to disorder amplitude and phase according to real and imaginary part of exp(iX(R)) , as is schematically sketched in fig. 1.Since in ordinary electron microscopy only the amplitude of the image wave can be recorded by the intensity of the image, the wave aberration has to be chosen such that the object component of interest (phase or amplitude) is directed into the image amplitude. Using an aberration free objective lens, for X=0 one sees the object amplitude, for X= π/2 (“Zernike phase contrast”) the object phase. For a real objective lens, however, the wave aberration is given by X(R) = 2π (.25 Csλ3R4 + 0.5ΔzλR2), Cs meaning the coefficient of spherical aberration and Δz defocusing. Consequently, the transfer functions sin X(R) and cos(X(R)) strongly depend on R such that amplitude and phase of the image wave represent only fragments of the object which, fortunately, supplement each other. However, recording only the amplitude gives rise to the fundamental problems, restricting resolution and interpretability of ordinary electron images:

scholarly journals Automated cellular structure extraction in biological images with applications to calcium imaging data

2018 ◽  
Author(s):  
Gal Mishne ◽  
Ronald R. Coifman ◽  
Maria Lavzin ◽  
Jackie Schiller
Keyword(s):  
Calcium Imaging ◽  
Image Plane ◽  
Cellular Level ◽  
Full Potential ◽  
Imaging Data ◽  
Image Domain ◽  
Biological Images ◽  
Large Populations ◽  
In Vivo Calcium Imaging

AbstractRecent advances in experimental methods in neuroscience enable measuring in-vivo activity of large populations of neurons at cellular level resolution. To leverage the full potential of these complex datasets and analyze the dynamics of individual neurons, it is essential to extract high-resolution regions of interest, while addressing demixing of overlapping spatial components and denoising of the temporal signal of each neuron. In this paper, we propose a data-driven solution to these challenges, by representing the spatiotemporal volume as a graph in the image plane. Based on the spectral embedding of this graph calculated across trials, we propose a new clustering method, Local Selective Spectral Clustering, capable of handling overlapping clusters and disregarding clutter. We also present a new nonlinear mapping which recovers the structural map of the neurons and dendrites, and global video denoising. We demonstrate our approach on in-vivo calcium imaging of neurons and apical dendrites, automatically extracting complex structures in the image domain, and denoising and demixing their time-traces.

scholarly journals The Design and Testing of 3DmoveR: an Experimental Tool for Usability Studies of Interactive 3D Maps

2018 ◽  
pp. 31-63 ◽  
Author(s):  
Lukáš Herman ◽  
Tomáš Řezník ◽  
Zdeněk Stachoň ◽  
Jan Russnák
Keyword(s):  
Spatial Data ◽  
Response Times ◽  
3D Visualization ◽  
User Interaction ◽  
Google Earth ◽  
Web Based ◽  
3D Environments ◽  
Camera Position ◽  
Interactive 3D ◽  
3D Scene

Various widely available applications such as Google Earth have made interactive 3D visualizations of spatial data popular. While several studies have focused on how users perform when interacting with these with 3D visualizations, it has not been common to record their virtual movements in 3D environments or interactions with 3D maps. We therefore created and tested a new web-based research tool: a 3D Movement and Interaction Recorder (3DmoveR). Its design incorporates findings from the latest 3D visualization research, and is built upon an iterative requirements analysis. It is implemented using open web technologies such as PHP, JavaScript, and the X3DOM library. The main goal of the tool is to record camera position and orientation during a user’s movement within a virtual 3D scene, together with other aspects of their interaction. After building the tool, we performed an experiment to demonstrate its capabilities. This experiment revealed differences between laypersons and experts (cartographers) when working with interactive 3D maps. For example, experts achieved higher numbers of correct answers in some tasks, had shorter response times, followed shorter virtual trajectories, and moved through the environment more smoothly. Interaction-based clustering as well as other ways of visualizing and qualitatively analyzing user interaction were explored.

400 Kv Electron Cryo-Microscopic Imaging Of Large Icosahedral Viruses Towards Atomic Resolution

1999 ◽  
Vol 5 (S2) ◽  
pp. 186-187
Author(s):  
Joanita Jakarta ◽  
Wah Chiu
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Clinical Manifestations ◽  
Image Data ◽  
Chromatic Aberration ◽  
Dimensional Structure ◽  
Depth Of Field ◽  
Periodic Arrays ◽  
Icosahedral Viruses ◽  
Simplex Virus

Three-dimensional structure studies provide important information about the organization of macromolecules, often revealing biological mechanisms and protein structure-function relationships. 400 KV electron cryo-microscopy is an emerging technology that is proving to be a powerful tool for studying the structures of large macromolecular assemblies that are often not tractable using other techniques. Its large depth of field makes it well-suited for imaging large objects to high resolution. In addition, a high accelerating voltage minimizes chromatic aberration yielding images of higher contrast. Recently a 400 KV electron cryo-microscope has been used to image periodic arrays of tubulin to 3.5 Å and single particles at somewhat lower resolutions (13 Å) providing practical demonstrations of its usefulness in modern structural biology. In this paper we present high resolution image data of two large icosahedral viruses: herpes simplex virus IB nucleocapsid (HSV IB) and rice dwarf virus (RDV). Human herpes virus (HSV) is associated with a spectrum of diseases ranging from cold sores to more severe clinical manifestations such as mental retardation.

scholarly journals Interactive 3D Exploration of RDF Graphs through Semantic Planes

2018 ◽  
Vol 10 (8) ◽  
pp. 81 ◽  
Author(s):  
Fabio Viola ◽  
Luca Roffia ◽  
Francesco Antoniazzi ◽  
Alfredo D’Elia ◽  
Cristiano Aguzzi ◽  
...  
Keyword(s):  
Semantic Web ◽  
3D Visualization ◽  
Data Representation ◽  
Knowledge Bases ◽  
Rdf Graph ◽  
Common Concept ◽  
Interactive 3D ◽  
3D Scene ◽  
Rdf Graphs ◽  
3D Exploration

This article presents Tarsier, a tool for the interactive 3D visualization of RDF graphs. Tarsier is mainly intended to support teachers introducing students to Semantic Web data representation formalisms and developers in the debugging of applications based on Semantic Web knowledge bases. The tool proposes the metaphor of semantic planes as a way to visualize an RDF graph. A semantic plane contains all the RDF terms sharing a common concept; it can be created, and further split into several planes, through a set of UI controls or through SPARQL 1.1 queries, with the full support of OWL and RDFS. Thanks to the 3D visualization, links between semantic planes can be highlighted and the user can navigate within the 3D scene to find the better perspective to analyze data. Data can be gathered from generic SPARQL 1.1 protocol services. We believe that Tarsier will enhance the human friendliness of semantic technologies by: (1) helping newcomers assimilate new data representation formats; and (2) increasing the capabilities of inspection to detect relevant situations even in complex RDF graphs.

scholarly journals EXPERIMENTS ON CALIBRATING TILT-SHIFT LENSES FOR CLOSE-RANGE PHOTOGRAMMETRY

2016 ◽  
Vol XLI-B5 ◽  
pp. 99-105 ◽  
Author(s):  
E. Nocerino ◽  
F. Menna ◽  
F. Remondino ◽  
J.-A. Beraldin ◽  
L. Cournoyer ◽  
...  
Keyword(s):  
Optical Axis ◽  
National Research Council ◽  
Image Plane ◽  
Limiting Factors ◽  
Depth Of Field ◽  
Small Object ◽  
Digital Cameras ◽  
Close Range Photogrammetry ◽  
Object Distance ◽  
Close Range

One of the strongest limiting factors in close range photogrammetry (CRP) is the depth of field (DOF), especially at very small object distance. When using standard digital cameras and lens, for a specific camera – lens combination, the only way to control the extent of the zone of sharp focus in object space is to reduce the aperture of the lens. However, this strategy is often not sufficient; moreover, in many cases it is not fully advisable. In fact, when the aperture is closed down, images lose sharpness because of diffraction. Furthermore, the exposure time must be lowered (susceptibility to vibrations) and the ISO increased (electronic noise may increase). In order to adapt the shape of the DOF to the subject of interest, the Scheimpflug rule is to be applied, requiring that the optical axis must be no longer perpendicular to the image plane. Nowadays, specific lenses exist that allow inclining the optical axis to modify the DOF: they are called tilt-shift lenses. In this paper, an investigation on the applicability of the classic photogrammetric model (pinhole camera coupled with Brown’s distortion model) to these lenses is presented. Tests were carried out in an environmentally controlled metrology laboratory at the National Research Council (NRC) Canada and the results are hereafter described in detail.

scholarly journals A New Method for Conservation of Ancient Colored Drawing on Hemp Textiles

2020 ◽  
Author(s):  
Jiaojiao Liu ◽  
Yuhu Li ◽  
Huiping Xing ◽  
Daodao Hu ◽  
Xiaolian Chao ◽  
...  
Keyword(s):  
Uv Light ◽  
Chromatic Aberration ◽  
Element Distribution ◽  
Depth Of Field ◽  
Conservation Treatment ◽  
Before And After ◽  
Wet Heat ◽  
Historical Culture ◽  
Restoration And Protection ◽  
Cultural Relics

Abstract As a kind of textile, hemp artifact is a valuable cultural heritage. Suffering from several degradation factors in the preservation of cultural relics, some ancient hemp colored-paintings have been damaged, further affected their ornamental values. Therefore, it is urged to take the suitable conservation measures to protect the precious hemp artifacts for the historical culture succession. In this paper, an examination and analysis of the hemp colored paintings were the first step to propose an appropriate conservation treatment. Ultra-depth-of-field microscope was used to identify the kinds of fiber, and scanning electron microscope (SEM) was utilized to observe their condition and surface morphology. The element distribution and composition were identified by SEM, energy disperse spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF). Gas chromatography-mass spectrometer (GC-MS) was applied to identify the kinds of binding media and amino acid composition. Moreover, novel reinforcement materials and technology were proposed with the principle of compatibility and feasibility. The properties of tensile strength, aging resistance and chromatic aberration were tested before and after dry heat aging, wet heat aging and UV light aging. After systematic examination and evaluation of the hemp colored paintings and reinforcement materials, the optimal conservation treatment was finally established, and the Chinese hemp painting as an example has been protected successfully. This paper provides new methods and ideas for the restoration and protection of the linen cultural relics, which would promote the progress of protecting valuable cultural heritages.

scholarly journals CALCULATION OF THE ACHROMATIC DIFFRACTION SYSTEM WITH CORRECTED SPHERICAL ABERRATION (part 2)

2020 ◽  
Vol 8 (1) ◽  
pp. 127-133
Author(s):  
Yury Ts. Batomunkuev ◽  
Alexandra A. Pechenkina
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Optical Element ◽  
Diffraction Order ◽  
Image Plane ◽  
Chromatic Aberration ◽  
Real Image ◽  
Optical Elements ◽  
A Value ◽  
Analytical Expressions

Achromatization of a three-component diffraction system consisting of one thick and two thin hologram optical elements is considered in the work. Analytical expressions are obtained for correcting the chromatic aberration of the position of a thick focusing hologram optical element by two scattering thin hologram optical elements in a given spectrum range. It is shown that achromatization is achieved for such a three-component system using two thin hologram elements located symmetrically on both sides of the thick element and having a value of the working diffraction order greater than the ratio of the focal length to the distance from the thin element to the image plane (at a given wavelength). The proposed three-component holographic system can be used to convert both an imaginary image into a real image and a real into an imaginary image in predetermined spectral regions of the visible, ultraviolet or infrared ranges of the spectrum.

Measuring and Tuning TEM Energy Filter Performance

1998 ◽  
Vol 4 (S2) ◽  
pp. 388-389
Author(s):  
H. Brink ◽  
G. Kothleitner ◽  
M.K. Kundmann
Keyword(s):  
Optical Properties ◽  
Energy Loss ◽  
Chromatic Aberration ◽  
Field Of View ◽  
Performance Criteria ◽  
Geometric Distortion ◽  
Filter Performance ◽  
Common Concern ◽  
Image Pixels ◽  
Loss Range

Although, critical performance criteria of TEM objective lenses, such as spherical and chromatic aberration and, more recently, 3-fold astigmatism, are of common concern, the important properties of TEM energy filters are less well-known and not often measured or quoted. In an effort to bring these to light, we have developed methods for automatically measuring and tuning three optical properties important to practical filter performance: non-isochromaticity, geometric distortion, and non-achromaticity.A filter is perfectly isochromatic if the range of electron energies that contribute to an energy-filtered image is the same across all image pixels. In practice, energy filters display some degree of nonisochromaticity, i.e. the energy-loss range forming the periphery of the image differs by anywhere from a fraction of an eV to as much as few eV from that forming the center of the field of view.

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