scholarly journals Image deconvolution using a characterization of sharp images in wavelet domain

2012 ◽  
Vol 32 (2) ◽  
pp. 295-304 ◽  
Author(s):  
Hui Ji ◽  
Jia Li ◽  
Zuowei Shen ◽  
Kang Wang
Keyword(s):  
Image Deconvolution ◽  
Wavelet Domain

Differentiating human cervical dysplastic and normal tissue through wavelet domain characterization of intrinsic fluorescence

2011 ◽  
Author(s):  
Rajatesh Gudibande ◽  
Meghdoot Mozumder ◽  
Rajbeer Singh ◽  
Prasanta K. Panigrahi ◽  
Sharad Gupta ◽  
...  
Keyword(s):  
Normal Tissue ◽  
Intrinsic Fluorescence ◽  
Wavelet Domain

A shearlet-based fast thresholded Landweber algorithm for deconvolution

2016 ◽  
Vol 14 (05) ◽  
pp. 1650032 ◽  
Author(s):  
Philipp Grohs ◽  
Željko Kereta ◽  
Uwe Wiesmann
Keyword(s):  
Optimization Problem ◽  
Motion Blur ◽  
Image Process ◽  
Image Deconvolution ◽  
The Novel ◽  
Wavelet Domain ◽  
Reconstruction Algorithms ◽  
Transform Coefficients ◽  
Shannon Wavelets

Image deconvolution is an important problem, which has seen plenty of progress in the last decades. Due to its ill-posedness, a common approach is to formulate the reconstruction as an optimization problem[Formula: see text] regularized by an additional sparsity-enforcing term. This term is often modeled as an [Formula: see text] norm measured in the domain of a suitable signal transform. The resulting optimization problem can be solved by an iterative approach via Landweber iterations with soft thresholding of the transform coefficients. Previous approaches focused on thresholding in the wavelet-domain. In particular, recent work [C. Vonesch and M. Unser, A fast thresholded Landweber algorithm for wavelet-regularized multidimensional deconvolution, IEEE Trans. Image Process. 17(4) (2008) 539–549.] has shown that the use of Shannon wavelets results in particularly efficient reconstruction algorithms. The present paper extends this approach to Shannon shearlets, which we also introduce in this work. We show that for anisotropic blurring filters, such as the motion blur, the novel shearlet-based approach allows for further a improvement in efficiency. In particular, we observe that for such kernels using shearlets instead of wavelets improves the quality of image restoration and SERG, when compared after the same number of iterations.

WAVELET CHARACTERIZATION OF DYADIC BMO NORM AND ITS APPLICATION IN IMAGE DECOMPOSITION FOR DISTINGUISHING BETWEEN TEXTURE AND NOISE

2011 ◽  
Vol 09 (03) ◽  
pp. 445-457 ◽  
Author(s):  
TAO ZHANG ◽  
QIBIN FAN
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Image Decomposition ◽  
Wavelet Domain ◽  
Wavelet Representation ◽  
Local Variance ◽  
Decomposition Models ◽  
Oscillating Patterns ◽  
The Relationship

Following the oscillating theory of Meyer, many image decomposition models have been proposed to split an image into two parts: structures and textures. But these models are not effective in the case of a noisy image, because both textures and noise are oscillating patterns. In this paper, we use the local variance measure to separate noise from textures. Firstly, we examine the relationship between dyadic BMO norm and local variance. Then, we give the wavelet representation of dyadic BMO norm and local variance, and further propose a method to distinguish between texture and noise in wavelet domain. In high frequency wavelet domain, we propose a decomposition model using local variance as constraints, while in low frequency domain, we use the shrinkage scheme to distinguish them. Finally, we present various numerical results on images to demonstrate the potential of our method.

scholarly journals Remarks on the Sommerfeld effect characterization in the wavelet domain

2018 ◽  
Vol 25 (1) ◽  
pp. 98-108 ◽  
Author(s):  
M. Varanis ◽  
J.M. Balthazar ◽  
A. Silva ◽  
A.G. Mereles ◽  
R. Pederiva
Keyword(s):  
Energy Source ◽  
Wavelet Transform ◽  
Mechanical System ◽  
Wavelet Packet ◽  
Mechanical Systems ◽  
Wavelet Domain ◽  
Sommerfeld Effect ◽  
Nonstationary Regime ◽  
Shear Building

In many applications in engineering, a mechanical system operates in the nonstationary regime, either partially of fully, creating the possibility to generate nonlinearities in them. Great efforts have been made to better understand and characterize these phenomena. One of several methods that are being used for the processing of signals of a nonstationary nature, as well as for the characterization of nonlinearities in mechanical systems, is the wavelet transform. A particular phenomenon that is seen in systems operating in the nonstationary regime is the Sommerfeld effect, which occurs due to the nonlinear interaction between a nonideal energy source and a mechanical system. This phenomenon can lead to high amplitudes of vibration for the system that in turn can cause damage in it. Therefore, this work presents an application of the continuous wavelet transform and the wavelet packet transform for the characterization of the Sommerfeld effect in mechanical systems where only the time response is at hand. Experimental procedures were performed where a nonideal energy source (an unbalanced DC motor) was used to excite (a) a portal frame and (b) a three-story shear-building. The results showed the effectiveness and the potential of the methods proposed.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

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