scholarly journals Image De-Quantization Using Plate Bending Model

Algorithms ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 110
Author(s):  
David Völgyes ◽  
Anne Martinsen ◽  
Arne Stray-Pedersen ◽  
Dag Waaler ◽  
Marius Pedersen
Keyword(s):  
Biharmonic Equation ◽  
Dynamic Range ◽  
Difference Threshold ◽  
Plate Bending ◽  
Original Signal ◽  
Plate Model ◽  
Local Maxima ◽  
Pixel Value ◽  
Discretized Image ◽  
Signal Approximation

Discretized image signals might have a lower dynamic range than the display. Because of this, false contours might appear when the image has the same pixel value for a larger region and the distance between pixel levels reaches the noticeable difference threshold. There have been several methods aimed at approximating the high bit depth of the original signal. Our method models a region with a bended plate model, which leads to the biharmonic equation. This method addresses several new aspects: the reconstruction of non-continuous regions when foreground objects split the area into separate regions; the incorporation of confidence about pixel levels, making the model tunable; and the method gives a physics-inspired way to handle local maximal/minimal regions. The solution of the biharmonic equation yields a smooth high-order signal approximation and handles the local maxima/minima problems.

scholarly journals Fast contrast enhancement by adaptive pixel value stretching

2018 ◽  
Vol 14 (8) ◽  
pp. 155014771879380
Author(s):  
Gang Cao ◽  
Huawei Tian ◽  
Lifang Yu ◽  
Xianglin Huang
Keyword(s):  
Contrast Enhancement ◽  
Dynamic Range ◽  
Computational Cost ◽  
Computer Applications ◽  
Visual Sensor ◽  
Visual Sensor Network ◽  
Image Contrast Enhancement ◽  
Quantitative Performance ◽  
Pixel Value ◽  
Adaptive Gamma Correction

In this article, we propose a fast and effective method for digital image contrast enhancement. The gray-level dynamic range of contrast-distorted images is extended maximally via adaptive pixel value stretching. The quantity of saturated pixels is set intelligently according to the perceptual brightness of global images. Adaptive gamma correction is also novelly used to recover the normal luminance in enhancing dimmed images. Different from prior methods, our proposed technique could be enforced automatically without complex manual parameter adjustment per image. Both qualitative and quantitative performance evaluation results show that, comparing with some recent influential contrast enhancement techniques, our proposed method achieves comparative or better enhancement quality at a surprisingly lower computational cost. Besides general computer applications, such merit should also be valuable in low-power scenarios, such as the imaging pipelines used in small mobile terminals and visual sensor network.

scholarly journals Two approaches for log-compression parameter estimation: Comparative study

2009 ◽  
Vol 6 (3) ◽  
pp. 419-425 ◽  
Author(s):  
Milorad Paskas
Keyword(s):  
Parameter Estimation ◽  
Comparative Study ◽  
Dynamic Range ◽  
Signal Reconstruction ◽  
Ultrasound Images ◽  
Original Signal ◽  
Compression Parameter ◽  
Nonlinear Compression

Standard ultrasound devices perform nonlinear compression reducing dynamic range of the signal. In order to reconstruct original signal it is necessary to find out statistics of the signal before and signal after compression. There are two techniques for compression parameter estimation or, that is equivalent, compressed signal reconstruction advised in literature. In the paper we perform comparison of these techniques both for computer generated signals and ultrasound images. .

Method of features construction for remote sensing images based on the characteristics of random point fields

2017 ◽  
Vol 2017 (45) ◽  
pp. 90-95
Author(s):  
R.Ya. Kosarevych ◽  
◽  
O.A. Lutsyk ◽  
B.P. Rusyn ◽  
V.V. Korniy ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Dynamic Range ◽  
Texture Features ◽  
Input Image ◽  
Image Resolution ◽  
Random Point ◽  
Local Maxima ◽  
Image Fragment ◽  
Point Field ◽  
Field Element

Texture features are widely used in remote sensing image classification. In most cases they are extracted from grayscale images without taking color information into consideration. The texture descriptors, which consist of characteristics of random point fields formed for pixels of distinct intensity of grayscale and color band images are presented. The input image is divided into fragments for the elements of each of which the histogram is constructed and their local maxima are determined. Size of fragments are chosen depending on image resolution. For each of the intensity of the dynamic range of the image, a random point field, as a set of geometric centers of fragments, is formed. By the formed configuration, each field is classified as cluster, regular or random. To form a description of image elements a distribution of the number of field elements for each intensity and fragment is constructed. Separately, the vectors of the point field element for each intensity in the image fragment and the point field element for the selected intensity are formed. Experimental results demonstrate that proposed descriptors yield performance compared to other state-of-the-art texture features.

Modified Strip Model for Analyzing the Line Heating Method-Part 2: Thermo-Elastic-Plastic Plates

1991 ◽  
Vol 35 (03) ◽  
pp. 266-275
Author(s):  
Amiram Moshaiov ◽  
Jong Gye Shin
Keyword(s):  
Research Work ◽  
Future Research ◽  
Plate Bending ◽  
Plate Model ◽  
Elastic Plates ◽  
Plastic Plate ◽  
Governing Equations ◽  
Line Heating ◽  
Heating Method ◽  
Elastic Plastic

A modified strip method is developed for analyzing the process of plate forming by the line heating method. The idea has been presented in Part 1 for analyzing elastic plates, and it is extended here to simulate approximately the transient thermo-elastic-plastic plate bending. Two cases are discussed. First, the case of uncoupled thermo-elastic-plastic plate is studied illustrating the use of a modified strip model. Second, generalized coupled governing equations for the thermo-elastic-plastic modified strip are derived and discussed. The results, with the use of a regular strip model, indicate a qualitative error in comparison with the use of a plate model, whereas with the use of a modified strip model a qualitative agreement is reached. Finally, suggestions for future research work are given.

Analysis of Companding Techniques Applied to Onboard Telemetry Systems

2012 ◽  
Vol 232 ◽  
pp. 915-918
Author(s):  
Marcio Barbosa Lucks ◽  
Heuller A.C. Procópio
Keyword(s):  
Dynamic Range ◽  
Quantization Noise ◽  
Original Signal ◽  
Wide Dynamic Range ◽  
Telecommunication Systems ◽  
Uniform Quantization ◽  
Noise Ratio

In order to increase the dynamic range and the signal-to-quantization noise ratio (SQNR) of telecommunication systems, companding techniques were developed, such as the μ-law and the A-law. These techniques allow a non-uniform quantization of the signal using a compressor circuit followed by a uniform quantizer in the transmitter and the reconstruction of the original signal on the receiver by means of an expander circuit. Some types of signals monitored during the flight of sounding vehicles and satellite launchers have a very wide dynamic range. In this paper, we propose and analyze the use of companding techniques in order to improve the SQNR of onboard telemetry systems.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

Slow-Scan CCD Observation of Backscattering Patterns in SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1308-1309
Author(s):  
F. Ouyang ◽  
D. A. Ray ◽  
O. L. Krivanek
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Lens System ◽  
Wide Dynamic Range ◽  
Peltier Cooler ◽  
Diffraction Patterns ◽  
Scanning Electron

Electron backscattering Kikuchi diffraction patterns (BKDP) reveal useful information about the structure and orientation of crystals under study. With the well focused electron beam in a scanning electron microscope (SEM), one can use BKDP as a microanalysis tool. BKDPs have been recorded in SEMs using a phosphor screen coupled to an intensified TV camera through a lens system, and by photographic negatives. With the development of fiber-optically coupled slow scan CCD (SSC) cameras for electron beam imaging, one can take advantage of their high sensitivity and wide dynamic range for observing BKDP in SEM.We have used the Gatan 690 SSC camera to observe backscattering patterns in a JEOL JSM-840A SEM. The CCD sensor has an active area of 13.25 mm × 8.83 mm and 576 × 384 pixels. The camera head, which consists of a single crystal YAG scintillator fiber optically coupled to the CCD chip, is located inside the SEM specimen chamber. The whole camera head is cooled to about -30°C by a Peltier cooler, which permits long integration times (up to 100 seconds).

Quantitative energy-filtered electron diffraction

1994 ◽  
Vol 52 ◽  
pp. 992-993
Author(s):  
R. Vincent
Keyword(s):  
Electron Diffraction ◽  
Inelastic Scattering ◽  
Dynamic Range ◽  
Electron Optics ◽  
Surface Layers ◽  
High Brightness ◽  
Inclined Surfaces ◽  
Perfect Symmetry ◽  
Amorphous Surface ◽  
The Ideal

Microanalysis and diffraction on a sub-nanometre scale have become practical in modern TEMs due to the high brightness of field emission sources combined with the short mean free paths associated with both elastic and inelastic scattering of incident electrons by the specimen. However, development of electron diffraction as a quantitative discipline has been limited by the absence of any generalised theory for dynamical inelastic scattering. These problems have been simplified by recent innovations, principally the introduction of spectrometers such as the Gatan imaging filter (GIF) and the Zeiss omega filter, which remove the inelastic electrons, combined with annual improvements in the speed of computer workstations and the availability of solid-state detectors with high resolution, sensitivity and dynamic range.Comparison of experimental data with dynamical calculations imposes stringent requirements on the specimen and the electron optics, even when the inelastic component has been removed. For example, no experimental CBED pattern ever has perfect symmetry, departures from the ideal being attributable to residual strain, thickness averaging, inclined surfaces, incomplete cells and amorphous surface layers.

Direct measurement of electron-diffraction-pattern intensities using an energy loss spectrometer

1989 ◽  
Vol 47 ◽  
pp. 668-669
Author(s):  
A. G. Jackson ◽  
M. Rowe
Keyword(s):  
Thermal Effects ◽  
Dynamic Range ◽  
Scattering Amplitude ◽  
Dynamical Theory ◽  
Site Symmetry ◽  
Proof Of Concept ◽  
Parallel Acquisition ◽  
Kinematic Approximation ◽  
Speed Up ◽  
Structure Calculations

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.

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