Vortex analysis in dynamic speckle images

Sendra, Gonzalo Hernán; Rabal, H.; Arizaga, Ricardo; Trivi, Marcelo

doi:10.1364/josaa.26.002634

Cited by 21 publications

(18 citation statements)

References 6 publications

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“…It adequately describes a simple and repeatable boiling experiment, namely the speckle pattern produced by an in-plane moving diffuser under adequate geometrical conditions of the observation system. This numerical experiment can be reproduced in practice 6 .…”

Section: Controlled Simulationsmentioning

confidence: 95%

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Signal Feature Extraction Using Granular Computing. Comparative Analysis with Frequency and Time Descriptors Applied to Dynamic Laser Speckle Patterns

Pra¹,

Passoni²,

Sendra³

et al. 2015

IJCIS

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The laser dynamic speckle is a phenomenon caused by the fluctuant interference of the laser light reflected from an illuminated surface where some kind of activity is taking place. Signals generated by the intensity changes in each pixel through the sequence are processed with the finality of identifying underlying activity in each point. In this work we compare the performance of a Rough Fuzzy Granular Descriptor (previously published) against a set of dynamic speckle descriptors based in time and frequency processing. To perform this evaluation a numerical simulation is proposed to explore their linearity, robustness, sensitivity related to the samples quantity, as well as also by their computing time. Also the robustness to inhomogeneous spatial intensity was evaluated in an experiment performed with the illuminated surface of an actual biological object.

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Section: Controlled Simulationsmentioning

confidence: 95%

“…x N (6) There is no a priori method to know in which frequency band is the "useful" information of the signal. Although the ESB is also an empirical descriptor, an initial bank of filters can be applied to detect the bands of interest 16 .…”

Section: Esbmentioning

confidence: 99%

Signal Feature Extraction Using Granular Computing. Comparative Analysis with Frequency and Time Descriptors Applied to Dynamic Laser Speckle Patterns

Pra¹,

Passoni²,

Sendra³

et al. 2015

IJCIS

Self Cite

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“…20 These laser beams have many important applications, for example, in astrophysics, 21 telecommunications 22 and micromanipulation of biological objects. 23 Furthermore, a new technique for displacement and flow measurements called optical vortex metrology was introduced, 24 and since then phase singularities have come to attract new attention in the field of optical metrology, 25,26 in particular, for characterization of dynamic processes. In 27 phase singularities in the complex signal are used for biological kinematic analysis and in the work 28 the paint drying process is studied experimentally using optical vortex metrology based approach.…”

Section: Introductionmentioning

confidence: 99%

Study of transparent particles in the volume of optical medium using digital holography and singular-optics approach

Nikolaeva

Petrov

2015

SPIE Proceedings

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The study of particles that are transparent to the probing radiation but introduce a phase delay appears to be relevant especially in the fields of biology and medicine. In this paper, we propose an approach to the study of the distribution of transparent particles suspended in a volume of optical medium, which combines the method of digital holography and the concept of singular optics. For the numerical study of the particles, we use a method, based on the obtainment and analysis of zerograms that correspond to the spatial distributions of amplitude zeros of the complex amplitude of the field. We explore the features of the application of analysis of the amplitude zero distributions in solving the problem of studying transparent particles suspended in a volume of the optical medium. We investigate the effect of various particle parameters on the recorded hologram and the structure and distribution of the amplitude zeros of the electromagnetic field. We demonstrate the use of histograms of distributions of local densities of amplitude zeros for the characterization of a higher number of transparent particles in volume. Numerical experiments on the use of analysis of the amplitude zeros of the field have shown that there are a number of particular qualities in the distribution of the zeros of amplitude, which can be subsequently used to develop more accurate and efficient method of characterization of transparent particles.

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“…2,4 Sendra et al 5 evaluated vortex behavior in dynamic speckle images, and pointed to the biological and industrial applications of analyzing vortex activity. They note there is a strong relationship between the motion of a scattering diffuser and the resultant motion of the optical vortices in the observed dynamic speckle pattern.…”

mentioning

confidence: 99%

“…Regardless of the numerical method used to generate the pseudo-phase, the operation simply exploits information already present in the signal without adding any new information. 5 Once a 2-D representation ofφ is generated, the singular points which identify the optical vortices can be located. These points then can be tracked as the speckle pattern dynamically evolves.…”

mentioning

confidence: 99%