Results 311 to 320 of about 1,689,718 (367)
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Applied Optics, 1987
Heterodyne techniques greatly improved the accuracy in readout systems for holographic interferometry and dual plate speckle photogrammetry, since the order of interference fringes is read via phase measurements. The limiting accuracy has been traditionally associated with scintillation noise.
J S, Kim +3 more
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Heterodyne techniques greatly improved the accuracy in readout systems for holographic interferometry and dual plate speckle photogrammetry, since the order of interference fringes is read via phase measurements. The limiting accuracy has been traditionally associated with scintillation noise.
J S, Kim +3 more
openaire +2 more sources
Journal of X-Ray Science and Technology, 2019
Ultrasound imaging has been used for diagnosing lesions in the human body. In the process of acquiring ultrasound images, speckle noise may occur, affecting image quality and auto-lesion classification.
Hyunho Choi, Jechang Jeong
semanticscholar +1 more source
Ultrasound imaging has been used for diagnosing lesions in the human body. In the process of acquiring ultrasound images, speckle noise may occur, affecting image quality and auto-lesion classification.
Hyunho Choi, Jechang Jeong
semanticscholar +1 more source
Noise reduction in speckle pattern interferometer
SPIE Proceedings, 2003In speckle pattern interferometry the starting phase is distributed randomly. Furthermore the background intensity and the modulation also are structured stochastically. This leads to a significant amount of noise in the interferogram analysis. Low modulated speckles are more difficult to evaluate than high modulated ones.
J. Kauffmann +2 more
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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.
H J, Gerritsen +2 more
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Learning a Deep Convolutional Network for Speckle Noise Reduction in Underwater Sonar Images
International Conference on Machine Learning and Computing, 2019Underwater sonar imaging system has been widely utilized to detect and identify the submerged objects of interest. However, imaging quality often suffers from the undesirable signal-dependent speckle noise during signal acquisition and transmission.
Yuxu Lu +3 more
semanticscholar +1 more source
Speckle noise reduction in SAS imagery
Signal Processing, 2007Synthetic aperture sonar (SAS) is actively used in sea bed imagery. Indeed high resolution images provided by SAS are of great interest, especially for the detection, localization and eventually classification of objects lying on sea bed. SAS images are highly corrupted by a granular multiplicative noise, called speckle noise which reduces spatial and ...
Fabien Chaillan +2 more
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Speckle Noise Reduction by Random Phase Shifters
Japanese Journal of Applied Physics, 1974Experimental results are given that show that a random phase shifter (RPS) is effective in reducing speckle noise caused by optical defects in coherent imaging systems, including holographic imaging systems. Here the RPS is composed of many tiny transparent blocks, each of which gives a definite phase shift such as O or pi to the transmitting light ...
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Speckle noise removal in medical ultrasonic image using spatial filters and DnCNN
Multimedia tools and applications, 2023Ali Kavand, Mehdi Bekrani
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Hybrid method for speckle noise reduction in digital holography.
Journal of The Optical Society of America A-optics Image Science and Vision, 2019In digital holography, the inherited speckle noise degrades imaging quality due to the coherent laser source. To overcome this problem, a hybrid method for speckle noise reduction is presented by combining a novel angular diversity approach with the ...
Jun Dong, Shuhai Jia, Hongqiang Yu
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