Non-local Mean Filter for Suppression of Speckle Noise in Ultrasound Images

Author(s):  
Avantika Srivastava ◽  
Vikrant Bhateja ◽  
Ananya Gupta ◽  
Aditi Gupta
2016 ◽  
Vol 195 ◽  
pp. 88-95 ◽  
Author(s):  
Jian Yang ◽  
Jingfan Fan ◽  
Danni Ai ◽  
Xuehu Wang ◽  
Yongchang Zheng ◽  
...  

Author(s):  
Jawad Fawaz Al-Asad ◽  
Adil Humayun Khan ◽  
Ghazanfar Latif ◽  
Wadii Hajji

Background: An approach based on QR decomposition, to remove speckle noise from medical ultrasound images, is presented in this paper. Methods: The speckle noisy image is segmented into small overlapping blocks. A global covariance matrix is calculated by averaging the corresponding covariances of the blocks. QR decomposition is applied to the global covariance matrix. To filter out speckle noise, the first subset of orthogonal vectors of the Q matrix is projected onto the signal subspace. The proposed approach is compared with five benchmark techniques; Homomorphic Wavelet Despeckling (HWDS), Speckle Reducing Anisotropic Diffusion (SRAD), Frost, Kuan and Probabilistic Non-Local Mean (PNLM). Results and Conclusion: When applied to different simulated and real ultrasound images, the QR based approach has secured maximum despeckling performance while maintaining optimal resolution and edge detection, and that is regardless of image size or nature of speckle; fine or rough.


Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 827 ◽  
Author(s):  
Chundi Jiang ◽  
Wei Yang ◽  
Yu Guo ◽  
Fei Wu ◽  
Yinggan Tang

Spatial correlation information between pixels is considered to be very important in thresholding methods. However, it is often ignored and thus unsatisfied segmentation results maybe obtained. To overcome this shortcoming, we propose a new image segmentation approach by taking not only pixels’ spatial information but also pixels’s gray level into account. First, a non-local mean filter is imposed on the image. Then the filtered image and the original image together are adopted to build a two dimensional histogram, it is called non-local mean two dimensional histogram. Finally, a minimum relative entropy criteria is used to select the ideal thresholding vector. Since the non-local mean filter process is performed in a neighborhood of current pixel, it carries out the spatial information of current pixel. Segmentation results on several images illustrate the effectiveness of the proposed thresholding method, whose segmentation accuracy are greatly improved compared to most existing thresholding methods.


2022 ◽  
pp. 1157-1173
Author(s):  
Bibekananda Jena ◽  
Punyaban Patel ◽  
G.R. Sinha

A new technique for suppression of Random valued impulse noise from the contaminated digital image using Back Propagation Neural Network is proposed in this paper. The algorithms consist of two stages i.e. Detection of Impulse noise and Filtering of identified noisy pixels. To classify between noisy and non-noisy element present in the image a feed-forward neural network has been trained with well-known back propagation algorithm in the first stage. To make the detection method more accurate, Emphasis has been given on selection of proper input and generation of training patterns. The corrupted pixels are undergoing non-local mean filtering employed in the second stage. The effectiveness of the proposed technique is evaluated using well known standard digital images at different level of impulse noise. Experiments show that the method proposed here has excellent impulse noise suppression capability.


Author(s):  
Kanuri Alekya ◽  
Konala Vijayalakshmi ◽  
Nainavarapu Radha ◽  
Durgesh Nandan

Author(s):  
Runpu Chen ◽  
Weidong Yu ◽  
Yunkai Deng ◽  
Robert Wang ◽  
Gang Liu ◽  
...  

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