Maintaining usable security in application domains such as healthcare or power systems requires an ongoing conversation among stakeholders such as end-users, administrators, developers, and policy makers. Each party has power to influence the design and implementation of the application and its security posture, and effective communication among stakeholders is one key to achieving influence an...

Speckle tracking methods overcome the major limitations of current Doppler methods for flow imaging and quantification: angle dependence and aliasing. In this paper, we review the development of speckle tracking, with particular attention to the advantages and limitations of two-dimensional algorithms that use a single transducer aperture. Ensemble tracking, a recent speckle tracking method bas...

Laser speckle imaging (LSI) based on the speckle contrast analysis is a simple and robust technique for imaging of heterogeneous dynamics. LSI finds frequent application for dynamical mapping of cerebral blood flow, as it features high spatial and temporal resolution. However, the quantitative interpretation of the acquired data is not straightforward for the common case of a speckle field form...

Digital Image Correlation (DIC) – also referred to as white light speckle technique – is an optical-numerical full-field measuring technique, which offers the possibility to determine in-plane displacement fields at the surface of objects under any kind of loading. For an optimal use of the method, the object of interest has to be covered with a speckle pattern. The present paper studies the ef...

We propose in this paper an efficient and fast wavelet based technique for speckle removal from SAR images. It relies on realistic distributions of the wavelet coefficients which represent mainly speckle noise at one hand and those that represent the useful signal corrupted by speckle at the other. We propose analytic models for these distributions, and the automatic computation of their parame...

| Speckle noise is an inherent property of SAR images. The discrete wavelet transform results in sub-band decompositions of SAR images which have Laplacian point statistics. We propose a Bayesian estimator to perform speckle reduction. We evaluate the speckle reduction results using two measurements: standarddeviation-to-mean ratio and target-to-clutter ratio. We show that good speckle reductio...

One of the major constraints facing laser speckle imaging for blood-flow measurement is reliable measurement of the correlation time (τ(C)) of the back-scattered light and, hence, the blood's speed in blood vessels. In this Letter, we present a new model expression for integrated speckle contrast, which accounts not only for temporal integration but spatial integration, too, due to the finite s...

Multi-look processing is a well known technique for reducing speckle in coherent imagery. This paper investigates the use of multi-look processing in range (frequency-compounding) on SAS images. The coherence between sub-images produced by frequency compounding is determined and a coherence model proposed. This is used to calculate the level of speckle reduction for a given number of looks and ...

Speckle arises when coherent light scattered from a rough surface is detected by an intensity detector that has a finite aperture, such as an observer. In a laser projection display, the presence of speckle tends to mask the image information and therefore its reduction is highly desirable. Speckle contrast reduction is based on averaging a number of speckle configurations within the spatio-tem...