A Quantitative Approach to Speckle Reduction via Frequency Compounding

1986 ◽  
Vol 8 (3) ◽  
pp. 151-164 ◽  
Author(s):  
G.E. Trahey ◽  
J.W. Allison ◽  
S.W. Smith ◽  
O.T. von Ramm
Keyword(s):  
Speckle Pattern ◽  
Imaging Systems ◽  
Center Frequency ◽  
Speckle Reduction ◽  
Optimal Method ◽  
Pattern Change ◽  
Multiple Imaging ◽  
Speckle Patterns ◽  
Contrast Reduction ◽  
Ultrasonic Images

Coherent speckle is a source of image noise in ultrasonic B-mode imaging. The use of multiple imaging frequencies has been suggested as a technique for speckle contrast reduction. This technique involves the averaging of images whose speckle patterns have been modified by a change in the spectrum of the transmitted or received acoustical pulse. We have measured the rate of this speckle pattern change in ultrasonic images as a function of the change in center frequency of the transmitted acoustical pulse. This data is used to quantitatively describe the trade-off of resolution loss versus speckle reduction encountered when frequency compounding is employed and to derive the optimal method of frequency compounding. These results are then used as a basis for describing the overall advisability of frequency compounding in ultrasonic imaging systems. Our analysis indicates that simple frequency compounding is counterproductive in improving image quality.

Frequency Compounding for Speckle Contrast Reduction in Phased Array Images

1982 ◽  
Vol 4 (3) ◽  
pp. 267-281 ◽  
Author(s):  
Paul A. Magnin ◽  
Olaf T. von Ramm ◽  
Frederick L. Thurstone
Keyword(s):  
Phased Array ◽  
Speckle Pattern ◽  
Signal To Noise ◽  
Speckle Contrast ◽  
Contrast Reduction ◽  
Ultrasonic Images

Frequency compounding is investigated as one technique for reducing the speckle contrast in phased array ultrasonic images. The degree of speckle contrast reduction was found to be inversely proportional to the bandwidth of the transmitted acoustic burst. The speckle pattern was also found to be anisotropic in its response to frequency compounding. Increases in the speckle pattern signal-to-noise ratios of 26 percent were found in B-mode images and increases as high as 84 percent were found in A-mode images.

Digital imaging and quantitative image analysis of polymer blends

1996 ◽  
Vol 54 ◽  
pp. 170-171
Author(s):  
Xiao Zhang
Keyword(s):  
Digital Imaging ◽  
Imaging Techniques ◽  
Imaging Systems ◽  
Polymer Science ◽  
Key Factors ◽  
Multiple Imaging ◽  
Quantitative Image ◽  
Digital Imaging Systems ◽  
Multi Phase ◽  
Network Technologies

Polymer microscopy involves multiple imaging techniques. Speed, simplicity, and productivity are key factors in running an industrial polymer microscopy lab. In polymer science, the morphology of a multi-phase blend is often the link between process and properties. The extent to which the researcher can quantify the morphology determines the strength of the link. To aid the polymer microscopist in these tasks, digital imaging systems are becoming more prevalent. Advances in computers, digital imaging hardware and software, and network technologies have made it possible to implement digital imaging systems in industrial microscopy labs.

SPECKLE STATISTICS IN THE PHOTON LOCALIZATION TRANSITION

2010 ◽  
Vol 24 (12n13) ◽  
pp. 1950-1988 ◽  
Author(s):  
Azriel Z. Genack ◽  
Jing Wang
Keyword(s):  
Steady State ◽  
Probability Distributions ◽  
Speckle Pattern ◽  
Frequency Variation ◽  
Localization Transition ◽  
Classical Waves ◽  
Speckle Patterns ◽  
The Many ◽  
Photon Localization ◽  
State Propagation

We review the statistics of speckle in the Anderson localization transition for classical waves. Probability distributions of local and integrated transmission and of the evolution of the structure of the speckle pattern are related to their corresponding correlation functions. Steady state and pulse transport can be described in terms of modes whose speckle patterns are obtained by decomposing the frequency variation of the transmitted field. At the same time, transmission can be purposefully manipulated by adjusting the incident field and the eigenchannels of the transmission matrix can be found by analyzing sets of speckle patterns for different inputs. The many aspects of steady state propagation are reflected in diverse, but simply related, parameters so that a single localization parameter encapsulates the character of transport on both sides of the divide separating localized from diffusive waves.

X-ray intensity fluctuation spectroscopy measurements of the charge density wave phases of NbSe3

2002 ◽  
Vol 12 (9) ◽  
pp. 3-8
Author(s):  
M. Sutton ◽  
Y. Li ◽  
J. D. Brock ◽  
R. E. Thorne
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Intensity Fluctuation ◽  
Speckle Pattern ◽  
Equations Of Motion ◽  
Density Wave ◽  
Electrical Currents ◽  
X Ray ◽  
Longitudinal Correlation ◽  
Speckle Patterns

An introduction to X-ray Intensity Fluctuation Spectroscopy (XIFS) is given by describing its relationship to speckle from coherent sources. A brief description of the relationship of XIFS measurements to the underlying equations of motion is given. Preliminary results for the charge density wave (CDW) system NbSe3 are then presented. Static speckle patterns are shown for the $\overrightarrow {Q}_1 = (0 .76$ 0) CDW peak showing that XIFS experiments are possible in this systom provided time constants are long enough. For electrical currents below threshold, a static speckle pattern is observed but for currents above threshold the speckles are smeared out showing movement of the CDW. It is also shown that above threshold, the longitudinal correlation length decreases.

Acoustic Speckle: Theory and Experimental Analysis

1979 ◽  
Vol 1 (4) ◽  
pp. 303-324 ◽  
Author(s):  
John G. Abbott ◽  
F. L. Thurstone
Keyword(s):  
Experimental Study ◽  
Experimental Analysis ◽  
Phased Array ◽  
Imaging System ◽  
Experimental Studies ◽  
Laser Speckle ◽  
Speckle Reduction ◽  
Multiple Images ◽  
Starting Point ◽  
Speckle Patterns

A theoretical and experimental study of speckle, as applied to ultrasonic imaging, is presented. The concept of laser speckle is briefly reviewed and is used as a starting point to explain the origin of acoustic speckle. The primary differences between these two phenomena are discussed and are confirmed by experiment. An experimental study of speckle reduction by summation of multiple images is also presented. Several techniques for generating independent speckle patterns for use in image summation schemes are proposed. A phased array, dynamically focused sector imaging system was used in all of the experimental studies reported.

scholarly journals Speckle-modulating optical coherence tomography in living mice and humans

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Orly Liba ◽  
Matthew D. Lew ◽  
Elliott D. SoRelle ◽  
Rebecca Dutta ◽  
Debasish Sen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Speckle Noise ◽  
Coherent Detection ◽  
Speckle Reduction ◽  
Optical Coherence ◽  
Coherent Noise ◽  
Speckle Patterns ◽  
Reduction Methods ◽  
Diagnostic Capabilities

Abstract Optical coherence tomography (OCT) is a powerful biomedical imaging technology that relies on the coherent detection of backscattered light to image tissue morphology in vivo. As a consequence, OCT is susceptible to coherent noise (speckle noise), which imposes significant limitations on its diagnostic capabilities. Here we show speckle-modulating OCT (SM-OCT), a method based purely on light manipulation that virtually eliminates speckle noise originating from a sample. SM-OCT accomplishes this by creating and averaging an unlimited number of scans with uncorrelated speckle patterns without compromising spatial resolution. Using SM-OCT, we reveal small structures in the tissues of living animals, such as the inner stromal structure of a live mouse cornea, the fine structures inside the mouse pinna, and sweat ducts and Meissner’s corpuscle in the human fingertip skin—features that are otherwise obscured by speckle noise when using conventional OCT or OCT with current state of the art speckle reduction methods.

Multi-Angle Compound Imaging

1998 ◽  
Vol 20 (2) ◽  
pp. 81-102 ◽  
Author(s):  
Søren K. Jespersen ◽  
Jens E. Wilhjelm ◽  
Henrik Sillesen
Keyword(s):  
Excellent Agreement ◽  
Imaging System ◽  
Speckle Pattern ◽  
Speckle Reduction ◽  
Conventional Imaging ◽  
Low Contrast ◽  
Spatial Compounding ◽  
Design And Implementation ◽  
Scanning Technique

This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared to conventional B-mode imaging MACI offers better defined tissue boundaries and lower variance of the speckle pattern, resulting in an image with reduced random variations. Design and implementation of a compound imaging system is described, images of rubber tubes and porcine aorta are shown and effects on visualization are discussed. The speckle reduction is analyzed numerically and the results are found to be in excellent agreement with existing theory. An investigation of detectability of low-contrast lesions shows significant improvements compared to conventional imaging. Finally, possibilities for improving diagnosis of atherosclerotic diseases using MACI are discussed.

Speckle reduction in THz imaging systems with multiple phase patterns

2006 ◽  
Author(s):  
Irina Jaeger ◽  
Johan Stiens ◽  
Gaetan Koers ◽  
Gert Poesen ◽  
Roger Vounckx
Keyword(s):  
Imaging Systems ◽  
Speckle Reduction ◽  
Thz Imaging ◽  
Multiple Phase
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