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Time Reversal of Speckle Noise
Physical Review Letters, 2011Focusing a wave in an unknown inhomogeneous medium is an open problem in wave physics. This work presents an iterative method able to focus in pulse-echo mode in an inhomogeneous medium containing a random distribution of scatterers. By performing a coherent summation of the random echoes backscattered from a set of points surrounding the desired focus,
Gabriel Montaldo +2 more
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Journal of the Optical Society of America, 1976
A theory is presented which relates the minimum detectable contrast level for an object in the presence of noise to the statistics of the speckle. Consideration is given to smoothing of the noise by multiple looks and by area. Measurements of the minimum detectable contrast are made for two types of speckle noise. First, a coherent, plane wave is added
Charles R. Christensen +3 more
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A theory is presented which relates the minimum detectable contrast level for an object in the presence of noise to the statistics of the speckle. Consideration is given to smoothing of the noise by multiple looks and by area. Measurements of the minimum detectable contrast are made for two types of speckle noise. First, a coherent, plane wave is added
Charles R. Christensen +3 more
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MLMVN in Speckle Noise Filtering
2020 IEEE Third International Conference on Data Stream Mining & Processing (DSMP), 2020In this paper, we use the multilayer neural network with multi-valued neurons (MLMVN) as an intelligent tool for speckle noise filtering. MLMVN is a complex-valued feedforward neural network, which was successfully used for solving various problems including classification, prediction and additive noise filtering.
Olivia Keohane +2 more
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A Speckle Noise Removal Method
Circuits, Systems, and Signal Processing, 2017During formation of echocardiographic images, speckle noise is introduced, which diminishes important information present in an image and effects physician's capability to interpret image correctly. In the literature, many techniques have been proposed to remove unwanted noise from the image.
Ayesha Saadia, Adnan Rashdi
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Elimination of Speckle Noise in Holograms with Redundancy
Applied Optics, 1968Holograms made of diffusely reflecting or diffusely illuminated objects can be scratched, spotted with dirt, and even broken into pieces without serious loss of information. This remarkable property is due to the redundancy introduced by diffuse illumination which, in effect, spreads information all over the hologram.
E. G. Ramberg +2 more
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Radar speckle: noise or information?
IGARSS '96. 1996 International Geoscience and Remote Sensing Symposium, 2002The authors examine radar speckle from a non-traditional perspective. Instead of viewing radar speckle as noise, they attempt to assess the information content of radar speckle. A speckle identification algorithm is developed to separate speckle from pixels of "normal" returns. The relationships between land cover types and the density and roughness of
Yongwei Sheng, Zong-Guo Xia
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2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), 2017
Speckle removal from single-channel and multi-dimensional SAR remains a difficult problem. In this paper, we are investigating the use of a Convolutional Neural Network (CNN), previously applied to the Super-Resolution problem, for speckle removal. Because speckle noise statistics is signal dependent, we are training the neural network on the residual ...
Mohamed Dahmane +3 more
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Speckle removal from single-channel and multi-dimensional SAR remains a difficult problem. In this paper, we are investigating the use of a Convolutional Neural Network (CNN), previously applied to the Super-Resolution problem, for speckle removal. Because speckle noise statistics is signal dependent, we are training the neural network on the residual ...
Mohamed Dahmane +3 more
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Reduction of speckle noise in multiwavelength contouring
Applied Optics, 2012We report on a method that can be used to improve the result of multiwavelength contouring in the case of objects with rough surface. It is based on the combined evaluation of multiple measurements with varying direction of illumination. While the individual measurements share the same systematics with respect to the shape of the investigated object ...
Christoph von Kopylow +3 more
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