Speckle Noise Suppression for Laser Active Imaging Based on Spectrum-Domain Constrain in Signal Subspace

2013 ◽  
Vol 40 (11) ◽  
pp. 1109001
Author(s):  
王灿进 Wang Canjin ◽  
孙涛 Sun Tao ◽  
王锐 Wang Rui ◽  
王挺峰 Wang Tingfeng ◽  
陈娟 Chen Juan
2021 ◽  
Author(s):  
Bingcai Liu ◽  
Rui Niu ◽  
Ailing Tian ◽  
Hongjun Wang ◽  
Xueliang Zhu ◽  
...  

2018 ◽  
Vol 14 (S345) ◽  
pp. 250-251
Author(s):  
Maria Giulia Ubeira Gabellini ◽  
Mario E. van den Ancker ◽  
Davide Fedele ◽  
Giuseppe Lodato ◽  
Carlo Felice Manara

AbstractUsing a novel method for speckle noise suppression from SPHERE-IFS data, we performed a systematic survey for disks in 22 Herbig Ae/Be stars, spatially resolving five disks and detecting seven new companion candidates. The fraction of sources with spatially resolved disks is systematically higher in the Meeus et al. (2001) group I sources, showing that disks are indeed more easily seen in scattered light in this sub-class of Herbig stars, consistent with the interpretation of group I sources having large gaps in their disks.


2013 ◽  
Vol 475-476 ◽  
pp. 282-286
Author(s):  
Tao Sun

In order to deal with the contradiction between suppressing speckle noise and reserving details in laser active imaging recognition system, a denoising method based on contour curvature is proposed. Due to the contour curvature, the pixels in the image are divided into different classes, which contain different amount of information. The filter parameters are different for each class. Firstly, the origin image is smoothed using wavelet soft thresholding, then the contours are extracted by Morphological edge detection operator. Due to the difference of contour curvature, the pixels are labeled with point of strong signal, point of weak signal or point of no signal. Pixels with different labels are filtered by Lee filter of different step width. Experiment result indicates that compared with classical Lee filter, the proposed method performs better in filtering and keeping edge information.


2017 ◽  
Vol 56 (5) ◽  
pp. 053103 ◽  
Author(s):  
Junmin Leng ◽  
Zhehai Zhou ◽  
Fubing Li ◽  
Qingyu Zheng ◽  
Gang Liu

2014 ◽  
Vol 875-877 ◽  
pp. 1982-1988
Author(s):  
Wen Liang Du ◽  
Xiao Lin Tian ◽  
Yan Kui Sun

Speckle noise is a common phenomenon in Optical Coherence Tomography (OCT) images. This paper describes a dynamic filtering approach for anterior chamber OCT images to reduce the speckle noise in wavelet domain. The approach proposed segments the OCT image into some parts and identifies if the parts have region of interest (ROI), which includes the anterior chamber tissues. Then, it suppresses noise with three different suppression strategies in part with ROI. For the part without ROI, it sets the discrete wavelet transform coefficients of this part to zero. Here, the sampling-based sub-band adaptive algorithm is used to distinguish the ROI; and the correlations of neighboring wavelet coefficients and the coefficients of the corresponding locations in adjacent decomposition levels are used to suppress the noise. The performance improvement over the previously published method is quantified in terms of noise suppression, image structural preservation and visual quality. The numerical values of the image quality metrics along with the qualitative analysis results indicated that the approach proposed has better performance.


Author(s):  
K. Yokochi ◽  
J. Nishikawa ◽  
N. Murakami ◽  
L. Abe ◽  
M. Tamura ◽  
...  

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