Results 251 to 260 of about 52,858 (287)

Speckle reduction by wavelet transform

Proceedings of 1997 Asia-Pacific Microwave Conference, 2002
Asia-Pacific Microwave Conference Proceedings, APMC ; 2 ; 542-545 ...
Lu, Y.H., Loh, Y.L., Yeo, T.S, Zhang, C.B.   +3 more
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Speckle Reduction by Spatial Sampling

Optical Engineering, 1976
It is well known that speckle reduction can be achieved by the noncoherent addition of independent image samples. Sampling can occur at either an image plane or at a Fresnel or Fraunhofer plane of a coherent imaging system. In the literature various comparisons have been made between continuous and discrete sampling methods which take place at a ...
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Speckle reduction in SAR imagery

Annual Meeting Optical Society of America, 1987
The high resolution in synthetic aperture radar (SAR) systems is reduced by the speckle appearing in SAR images. This speckle noise is generated by the coherent processing of radar signals and is similar to optical speckle. This multiplicative noise in radar images may be reduced by computer spatial processing: noise smoothing algorithms are developed ...
E. Harvey, G. April
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Optimal speckle reduction in polarimetric SAR imagery

IEEE Transactions on Aerospace and Electronic Systems, 1990
Speckle is a major cause of degradation in synthetic aperture radar (SAR) imagery. With the availability of fully polarimetric, high-resolu tion SAR data, it is possible to use the three complex elements (HH, HV, VV) of the polarimetric scattering matrix to reduce this speckle.
L.M. Novak, M.C. Burl
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Geometric Speckle Reduction.

1986
Abstract : The presence of speckle in imagery produced with coherent illumination (e.g., synthetic aperture radar) reduces the detectability of objects in the images. It also reduces the effectiveness of some computer algorithms (e.g., edge detection) designed for automatic image analysis.
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Speckle Reduction by Unidirectional Averaging

Optica Acta: International Journal of Optics, 1975
It is shown that for the holographic reconstruction of diffuse objects the use of a vibrating coherent source decreases the contrast of the speckle pattern, and that for certain classes of objects resolution is not affected. This is true in particular for grating-like objects when the source is vibrated in a direction parallel to the lines of the ...
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Holographic speckle reduction by complementary spatial sampling

Applied Optics, 1977
A technique using complementary sampling in the reconstruction process is proposed for speckle reduction in holographic imaging. This method would not suffer the resolution reduction experienced with the simple random sampling method that has been proposed [F. T. S. Yu and E. Wang, Appl. Opt. 12, 1656 (1973)].
A, Tai, F T, Yu
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Speckle reduction of ultrasound images

Proceedings of the First Joint BMES/EMBS Conference. 1999 IEEE Engineering in Medicine and Biology 21st Annual Conference and the 1999 Annual Fall Meeting of the Biomedical Engineering Society (Cat. No.99CH37015), 2003
We describe a method to reduce speckles of ultrasound images. We first segment an ultrasound image with speckle segmentation algorithm. We compute an adjacency graph representation of the speckles. For each speckle region, we compute its area, mean and variation.
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Speckle reduction in ultrasound imaging

The Journal of the Acoustical Society of America, 1998
A system and a method for generating an ultrasound image of an interrogation region in an object with a transducer with a two-dimensional array of transducer elements, includes the steps of generating an ultrasound beam by activating many transducer elements of the two-dimensional array; electronically controlling the beam to illuminate substantially ...
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Speckle reduction in synthetic-aperture-radar imagery

Optics Letters, 1990
Speckle appearing in synthetic-aperture-radar images degrades the information contained in these images. Speckle noise can be suppressed by adapted local processing techniques, permitting the definition of statistical parameters inside a small window centered on each pixel of the image.
E R, Harvey, G V, April
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