We study screening of optical singularities in random optical fields with two widely different length scales. We call the speckle patterns generated by such fields speckled speckle, because the major speckle spots in the pattern are themselves highly speckled. We study combinations of fields whose components exhibit short- and long-range correlations and find unusual forms of screening.

The probability density function and average contrast of the sum of n uncorrelated, partially developed speckle patterns have been theoretically investigated. A new form of the probability density function is given for the sum of n uncorrelated, partially developed speckle patterns under the assumption that the individual speckle fields to be added follow the circular statistics.

In recent time, ultrasound imaging is a popular modality for various medical applications. The presence of speckle noise affects difficulties on features extraction and quantitative measurement of ultrasound images. This paper proposes a new method to suppress the speckle noise while attempting to preserve the image content using combination of Gaussian filter and discrete cosine transform (DCT...

Image denoising has become a very essential exercise all through the diagnosis especially in case of medical image processing involving ultrasound. Speckle pattern is one of the most complicated multiplicative noise which hardly degrades visual quality of clinical ultrasound images. Real time ultrasound images posses inherited speckle pattern which reduces its resolution and contrast there by d...

The occurrence and smoothing of speckle are studied as a function of the line width for a highly collimated illuminating source. A general theory is presented for speckling in the image of a partially diffuse, phase type of object, which has a variable number of random scattering centers per resolution element. Then, an expression is derived for the wavelength spacing required to decouple the s...

The speckle is omnipresent in synthetic aperture radar (SAR) images as an intrinsic characteristic. However, it is unwanted in certain applications. Therefore, intelligent filters for speckle reduction are of great importance. It has been demonstrated in several literatures that the non-local means filter can reduce noise while preserving details. This paper discusses non-local means filter for...

In medical image processing, Image denoising plays a very important role in diagnosis. Medical images are very much inconsistent. In medical imaging, Ultrasound is very popular due to its low cost, least harmful to human body, real time system and small in size. Besides itsadvantage,It suffers from a major problem i.e. speckle noise which reduces the diagnosis ability. Speckle noise is the resu...

In this study, a new speckle reduction method was proposed in terms of by Bidimensional Empirical Mode Decomposition (BEMD). In this method, the SAR image containing speckle noise was decomposed into a number of elementary components by using BEMD and then the extremal points are done the boundary equivalent extension after screening and the residual continue to be done the boundary equivalent ...

A common problem in experimental mechanics is that when a sample is studied in, e.g. a tensile test machine, the sample is often simultaneously exposed to rigid body motions as small deformations occur. These two movements, the rigid body motion and the deformation, are often talked about as displacement fields. The sought deformation field is often in the micrometer range, while rigid body mot...

A theoretical model was previously developed to evaluate the relationship between the dynamics of ultrasonic speckle and its underlying tissue. The model is divided into an instrumental part represented by the point spread function (in the far field) of the ultrasonic apparatus and a moving tissue component described by a collection of scatterers. By computing the convolution of these terms and...