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.

scholarly journals Aperture Phase Modulation with Adaptive Optics: A Novel Approach for Speckle Reduction and Structure Extraction in Optical Coherence Tomography

2018 ◽  
Author(s):  
Pengfei Zhang ◽  
Suman K. Manna ◽  
Eric B. Miller ◽  
Yifan Jian ◽  
Ratheesh Kumar Meleppat ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Adaptive Optics ◽  
Phase Modulation ◽  
Imaging System ◽  
Speckle Pattern ◽  
Speckle Noise ◽  
Image Resolution ◽  
Speckle Reduction ◽  
Universal Method ◽  
Optical Coherence

Abstract:Speckle is an inevitable consequence of the use of coherent light in optical coherence tomography (OCT), and often acts as noise that obscures micro-structures of biological tissue. We here present a novel method of suppressing speckle noise intrinsically compatible with adaptive optics (AO) in OCT system: by modulating the phase inside the imaging system pupil aperture with a segmented deformable mirror, thus producing minor perturbations in the point spread function (PSF) to create un-correlated speckle pattern between B-scans, and further averaging to wash out the speckle but maintain the structures. It is a well-controlled and universal method which can efficiently determine the optimal range of phase modulation that minimizing speckle noise while maximizing image resolution and signal strength for different systems and/or samples. As an active method, its effectiveness and efficiency were demonstrated by both ex-vivo non-biological and in-vivo biological applications.

Note: Design and implementation of a home-built imaging system with low jitter for cold atom experiments

2016 ◽  
Vol 87 (5) ◽  
pp. 056108
Author(s):  
A. J. Hachtel ◽  
M. C. Gillette ◽  
E. R. Clements ◽  
S. Zhong ◽  
M. R. Weeks ◽  
...  
Keyword(s):  
Imaging System ◽  
Cold Atom ◽  
Design And Implementation ◽  
Low Jitter

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.

Design and implementation of infrared thermal imaging system based on SOPC

2021 ◽  
Vol 36 (6) ◽  
pp. 886-895
Author(s):  
Hai-lin ZHONG ◽  
◽  
Yue-tao YANG ◽  
Xin WANG ◽  
Feng CAO ◽  
...  
Keyword(s):  
Thermal Imaging ◽  
Imaging System ◽  
Infrared Thermal Imaging ◽  
Design And Implementation ◽  
Thermal Imaging System
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