Results 241 to 250 of about 3,337,138 (296)

Geometric filter for speckle reduction

Applied Optics, 1985
An algorithm is described which reduces speckle noise in images. It is a nonlinear algorithm based on geometric concepts. Tests were performed on synthetic aperture radar images which show that it compares favorably with a 3 × 3 median filter.
Thomas R Crimmins
exaly   +3 more sources

Speckle reduction in coherent information processing

Proceedings of the IEEE, 1996
Speckle reduction techniques have been developed as one of the most active research fields in coherent optical information processing, together with the investigations of speckle statistics and coherence theory. The principles of speckle reduction are classified to five categories: 1) control of spatial coherence, 2) control of temporal coherence, 3 ...
T Asakura, T Iwai
exaly   +2 more sources

Speckle reduction with edge-preserving

1997 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2002
Coherent imagery emerges as one of the major domains in image processing and includes topics as diversified as radar, medical and surface analysis. Whatever the application, the resulting image is noisy corrupted. In coherent imaging, images suffer from speckle noise, whose main characteristic is to be multiplicative.
Pierre Mathieu, Laurent Dirat, Xavier Dupuis, Michel Barlaud   +3 more
openaire   +2 more sources

Echocardiographic speckle reduction comparison

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2011
In this paper, a detailed description and comparison of speckle reduction of medical ultrasound, and in particular echocardiography, is presented. Fifteen speckle reduction filters are described in a detailed fashion to facilitate implementation for research and evaluation.
Seán, Finn, Martin, Glavin, Edward, Jones   +2 more
openaire   +2 more sources

Partly Polarized Speckles and Speckle Reduction in Interferometry

2008 14th Conference on Microwave Techniques, 2008
In this paper we discuss problems in an interferometer which arise when the interferometer uses a conventional, so-called 'non-cooperative' target rather than a mirror. Under these conditions, the reflected light assumes the character of a speckle field which requires that we describe its statistical properties by applying first order statistics of ...
Petr Kucera, Friedemann Mohr
openaire   +1 more source

Speckle Reduction Processing

SPIE Proceedings, 1987
Speckle is believed to be a significant degrading factor in ultrasonic images, and likely impairs the detectability of low contrast tumors and clinical scans. One method of reducing speckle, termed frequency diversity processing, uses multiple, narrow-band filters applied to the received RF signal.
Steve M. Gehlbach, F. G. Sommer
openaire   +1 more source

Assessment of hybrid speckle reduction algorithms

Physics in Medicine and Biology, 1991
A consequence of employing coherent detection methods in medical ultrasound imaging systems is the occurrence of interference effects in the received echo field, which produce the speckle artefact. Speckle can severely degrade the information content of the image, and its efficient removal from ultrasound pulse-echo images is the focus of a number of ...
F, Forsberg, A J, Healey, S, Leeman, J A, Jensen   +3 more
openaire   +2 more sources

Speckle noise reduction for ultrasonic images

SMC'03 Conference Proceedings. 2003 IEEE International Conference on Systems, Man and Cybernetics. Conference Theme - System Security and Assurance (Cat. No.03CH37483), 2004
This paper presents a method to enhance ultrasonic images that are commonly plagued with a special type of acoustic noise called speckles. To reduce the noise effect, filters such as the weighted median filter, adaptive trimmed mean filter, two dimensional weighted Savitzky-Golay filter (2D-WSGF) have been studied.
Chung-Chang Wu, Chun-Jun Huang, Jung-Hua Wang   +2 more
openaire   +2 more sources