METHODS AND ALGORITHMS FOR THE COMPLETE PROCESSING OF A POSTDETECTOR LOW-CONTRAST OPTICAL IMAGE

2018 ◽  
pp. 99-107
Author(s):  
V. V. Lavrov ◽  
R. S. Luchkin ◽  
O. I. Nemykin ◽  
M. E. Prokhorov ◽  
Yu. G. Ryndin ◽  
...  
Keyword(s):  
Optical Image ◽  
Structural Elements ◽  
Filtration Process ◽  
Low Contrast ◽  
Information Object ◽  
Detection Stage ◽  
Metric Structures ◽  
Spot 5 ◽  
Integrated Indicators ◽  
Complete Processing

Methods and algorithms for the complete processing of a post-detector low-contrast optical image (OI) of an unknown remote object obtained by ground-based optical means of observation under conditions of a complex background situation are considered. The purpose of processing is to separate and interpret at least with the help of the analyst, of the main constructive elements using the integrated indicators introduced in [6] and the characteristics of the analyzed OI, which are connected by the information, topological and metric structures of the OI. The stages of processing the OI include extracting the image-containing information object of the image portion (detection) and filtration of the OI, using recursive rank filtering. The final stages of processing include the segmentation of the OI and the allocation on it constructive elements using the apparatus of graph theory. An example of image processing of a Spot-5 spacecraft obtained in real conditions is given. It is shown that in this case at the detection stage it is possible to reduce the volume of information processed at subsequent stages by 8 times, in the filtration process to increase the compactness of the OI and to increase its connectivity in comparison with the post-detection OI. As a result of segmentation and allocation of constructive elements, three structural elements that can be interpreted as a spacecraft case and two remote panels can be identified with the analyst’s participation.

Contour-based segmentation and visualization of electron tomographic volumes

1995 ◽  
Vol 53 ◽  
pp. 1082-1083
Author(s):  
M. Marko ◽  
A. Leith ◽  
K. Buttle ◽  
Y. Li
Keyword(s):  
Spatial Frequency ◽  
High Voltage ◽  
Structural Information ◽  
Electron Tomography ◽  
Tomographic Reconstruction ◽  
Structural Elements ◽  
Frequency Range ◽  
Low Contrast ◽  
Tremendous Amount

Electron tomography is increasingly employed to obtain highly-detailed 3-D structural information from complex biological specimens, when such information cannot be obtained otherwise. Thick sections (ca. 0.25-3 μm), which require an intermediate- or high-voltage EM, are often used so that an appreciable portion of the structure of interest can be contained within the section. Because of this relatively large amount of material, volumes made by tomographic reconstruction are often filled with a tremendous amount of detail, not all of which is of interest. Often, in the absence of special stains, the structures of interest have low contrast compared to surrounding or adjoining structures. Typically, all the structures are embedded in the "ground cytoplasm", which has nonuniformlydispersed small structural elements that have the same density and spatial-frequency range as the structures of interest. In addition, the density of a given structure may vary within an image due to non-uniform staining. In these situations, the segmentation of the volume to isolate the interesting portions of the structure presents a formidable problem.

ALGORITHMS FOR SEGMENTING A DIGITAL IMAGE OF AN UNKNOWN OBJECT AND ISOLATING ITS CONSTRUCTIVE ELEMENTS ON A LOW-CONTRAST AFTERDETECTOR IMAGE

2018 ◽  
pp. 108-113
Author(s):  
V. V. Lavrov ◽  
R. S. Luchkin ◽  
O. I. Nemykin ◽  
M. E. Prokhorov ◽  
Yu. G. Ryndin
Keyword(s):  
Mathematical Logic ◽  
Graph Theory ◽  
Structural Elements ◽  
Threshold Intensity ◽  
Affine Transformations ◽  
Low Contrast ◽  
Binary Images ◽  
Two Stages ◽  
Contrast Image ◽  
Unknown Object

Algorithms for segmenting an optical image (OI) of an unknown remote object and isolating its main constructive elements on a low-contrast image are considered. The processing obtaining after the performed rank filtration of the image of the object, the description of which is specified in the form of a set of bitmaps formed at different threshold intensity levels, is carried out in two stages. At the first stage, the problem of segmentation of binary images is solved using the methods of graph theory and the apparatus of mathematical logic. With the participation of the analyst, the most qualitative image is picked out in the representation of the set of related domains. With Using the representation of the obtained OI in the form of a graph forest, the task of isolating the basic structural elements of the object is solved at the next stage of processing. Formations are made of estimates of their parameters, invariant to affine transformations and to scaling of the image intensity. These estimates are expedient for use in recognition.

scholarly journals Integrated NIR-HE based SPOT-5 image enhancement method for features preservation and edge detection

2021 ◽  
Vol 24 (3) ◽  
pp. 1499
Author(s):  
Farizuwana Akma Zulkifle ◽  
Rohayanti Hassan ◽  
Mohammad Nazir Ahmad ◽  
Shahreen Kasim ◽  
Tole Sutikno ◽  
...  
Keyword(s):  
Edge Detection ◽  
Near Infrared ◽  
Contrast Ratio ◽  
Wavelength Region ◽  
Histogram Equalization ◽  
Low Contrast ◽  
Infrared Wavelength ◽  
Image Enhancements ◽  
Filter Methods ◽  
Spot 5

Recently, many researchers have directed their attention to methods of predicting shorelines by the use of multispectral images. Thus, a simple and optimised method using image enhancements is proposed to improve the low contrast of the Satellite pour l'Observation de la Terre-5 (SPOT-5) images in the detection of shorelines. The near-infrared (NIR) channel is important in this study to ensure the contrast of the vegetated area and sea classification, due to the high reflectance of leaves in the near infrared wavelength region. This study used five scenes of interest to show the different results in shoreline detection. The results demonstrated that the proposed method performed in an enhanced manner as compared to current methods when dealing with the low contrast ratio of SPOT-5 images. As a result, by utilising the near-infrared histogram equalization (NIR-HE), the contrast of all datasets was efficiently restored, producing a higher efficiency in edge detection, and achieving higher overall accuracy. The improved filtering method showed significantly better shoreline detection results than the other filter methods. It was concluded that this method would be useful for detecting and monitoring the shoreline edge in Tanjung Piai.

Restoration of CT Images Corrupted With Fixed Valued Impulse Noise Using an Optimum Decision-Based Filter

2018 ◽  
pp. 220-239
Author(s):  
Priyank Saxena ◽  
R. Sukesh Kumar
Keyword(s):  
Radiation Dose ◽  
Impulse Noise ◽  
Image Data ◽  
Ct Images ◽  
Contrast Resolution ◽  
Low Contrast ◽  
Optimum Decision ◽  
Noticeable Improvement ◽  
Detection Stage ◽  
Salt And Pepper

The main aim of this chapter is to perform the restoration of computed tomography (CT) images acquired at the reduced level of radiation dose. Reduction in radiation dose affects the image quality as it increases noise and decreases low contrast resolution. In this chapter, an optimum decision-based filter (ODBF) is proposed as an image-space denoising technique, to detect and restore the low dose CT (LDCT) images corrupted with fixed valued impulse noise (salt and pepper) of unequal density. The detection stage employs k-means clustering to discriminate the noise-free pixels from the noisy-pixels by splitting the image data into three clusters of different intensities. The restoration stage employs mask else trimmed median (METM) estimation followed by an optional adaptive mask sizing for restoration of noisy pixels. The proposed method demonstrates noticeable improvement over other existing methods in restoration of LDCT images while maintaining the image contrast and edge details.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

One Million Direct Magnification Microscopy

1971 ◽  
Vol 29 ◽  
pp. 166-167
Author(s):  
J. A. Hugo ◽  
V. A. Phillips
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Illumination Level ◽  
Level Of Detail ◽  
Photographic Emulsion ◽  
Low Contrast ◽  
Fluorescent Screen ◽  
Resolution Electron ◽  
Lattice Images ◽  
Electron Microscopes

A continuing problem in high resolution electron microscopy is that the level of detail visible to the microscopist while he is taking a picture is inferior to that obtainable by the microscope, readily readable on a photographic emulsion and visible in an enlargement made from the plate. Line resolutions, of 2Å or better are now achievable with top of the line 100kv microscopes. Taking the resolution of the human eye as 0.2mm, this indicates a need for a direct viewing magnification of at least one million. However, 0.2mm refers to optimum viewing conditions in daylight or the equivalent, and certainly does not apply to a (colored) image of low contrast and illumination level viewed on a fluorescent screen through a glass window by the dark-adapted eye. Experience indicates that an additional factor of 5 to 10 magnification is needed in order to view lattice images with line spacings of 2 to 4Å. Fortunately this is provided by the normal viewing telescope supplied with most electron microscopes.

Field Emission SEM Equipped With Noise Compensator

1973 ◽  
Vol 31 ◽  
pp. 302-303
Author(s):  
S. Saito ◽  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Contrast ◽  
Probe Current ◽  
High Resolution Images ◽  
Scanning Electron

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.

Analysis of 3-d molecular distribution with the digital imaging microscope

1988 ◽  
Vol 46 ◽  
pp. 40-41
Author(s):  
W.A. Carrington ◽  
F.S. Fay ◽  
K.E. Fogarty ◽  
L. Lifshitz
Keyword(s):  
Image Restoration ◽  
Digital Imaging ◽  
Fluorescent Dyes ◽  
Optical Axis ◽  
Computer Hardware ◽  
Computer Algorithms ◽  
Low Contrast ◽  
Specific Proteins ◽  
Effective Use ◽  
Single Living Cells

Advances in digital imaging microscopy and in the synthesis of fluorescent dyes allow the determination of 3D distribution of specific proteins, ions, GNA or DNA in single living cells. Effective use of this technology requires a combination of optical and computer hardware and software for image restoration, feature extraction and computer graphics.The digital imaging microscope consists of a conventional epifluorescence microscope with computer controlled focus, excitation and emission wavelength and duration of excitation. Images are recorded with a cooled (-80°C) CCD. 3D images are obtained as a series of optical sections at .25 - .5 μm intervals.A conventional microscope has substantial blurring along its optical axis. Out of focus contributions to a single optical section cause low contrast and flare; details are poorly resolved along the optical axis. We have developed new computer algorithms for reversing these distortions. These image restoration techniques and scanning confocal microscopes yield significantly better images; the results from the two are comparable.

Resistance Monitor and Control for Vacuum Evaporation of Metals and Carbon

1976 ◽  
Vol 34 ◽  
pp. 572-573
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley
Keyword(s):  
Electronic Device ◽  
Point Sources ◽  
High Contrast ◽  
Variable Resistor ◽  
Quality Of Results ◽  
Low Contrast ◽  
Evaporation Source ◽  
And Control ◽  
At Will

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.

“High Resolution High Voltage Electron Microscopy”

1968 ◽  
Vol 26 ◽  
pp. 326-327
Author(s):  
Benjamin M. Siegel
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Voltage ◽  
Full Potential ◽  
Contrast Imaging ◽  
High Voltage Electron Microscopy ◽  
Low Contrast ◽  
Voltage Electron ◽  
Critical Areas ◽  
High Voltage Electron

The potential advantages of high voltage electron microscopy for extending the limits of resolution and contrast in imaging low contrast objects, such as biomolecular specimens, is very great. The results of computations will be presented showing that at accelerating voltages of 500-1000 kV it should be possible to achieve spacial resolutions of 1 to 1.5 Å and using phase contrast imaging achieve adequate image contrast to observe single atoms of low atomic number.The practical problems associated with the design and utilization of the high voltage instrument are, optimistically, within the range of competence of the state of the art. However, there are some extremely important and critical areas to be systematically investigated before we have achieved this competence. The basic electron optics of the column required is well understood, but before the full potential of an instrument capable of resolutions of better than 1.5 Å are realized some very careful development work will be required. Of great importance for the actual achievement of high resolution with a high voltage electron microscope is the fundamental limitation set by the characteristics of the high voltage electron beam that can be obtained from the accelerator column.

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