A region-adaptive non-local denoising algorithm for low-dose computed tomography images

Autor: Pengcheng Zhang, Yi Liu, Zhiguo Gui, Yang Chen, Lina Jia
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Mathematical Biosciences and Engineering, Vol 20, Iss 2, Pp 2831-2846 (2023)
Druh dokumentu: article
ISSN: 1551-0018
DOI: 10.3934/mbe.2023133?viewType=HTML
Popis: Low-dose computed tomography (LDCT) can effectively reduce radiation exposure in patients. However, with such dose reductions, large increases in speckled noise and streak artifacts occur, resulting in seriously degraded reconstructed images. The non-local means (NLM) method has shown potential for improving the quality of LDCT images. In the NLM method, similar blocks are obtained using fixed directions over a fixed range. However, the denoising performance of this method is limited. In this paper, a region-adaptive NLM method is proposed for LDCT image denoising. In the proposed method, pixels are classified into different regions according to the edge information of the image. Based on the classification results, the adaptive searching window, block size and filter smoothing parameter could be modified in different regions. Furthermore, the candidate pixels in the searching window could be filtered based on the classification results. In addition, the filter parameter could be adjusted adaptively based on intuitionistic fuzzy divergence (IFD). The experimental results showed that the proposed method performed better in LDCT image denoising than several of the related denoising methods in terms of numerical results and visual quality.
Databáze: Directory of Open Access Journals