Title :
Adaptive Non-local Means Denoising Algorithm for Cone-Beam Computed Tomography Projection Images
Author :
Huang, Kuidong ; Zhang, Dinghua ; Wang, Kuyu ; Li, Mingjun
Author_Institution :
Lab. of Contemporary Design & Integrated Manuf. Technol., Northwestern Polytech. Univ., Xi´´an, China
Abstract :
Aiming at the difficulty of choosing filtering parameters of Non-Local Means (NLM) denoising algorithm for Cone-Beam Computed Tomography (CBCT) projection images, an adaptive NLM denoising algorithm is proposed. First, a simplified noise estimation method based on sub-block division is proposed to replace the approach of designating the background region, which can adaptively identify the background region and estimate the noise level when the background region is changed obviously. And then an algorithm of adaptively obtaining filter strengths of projection images is proposed by analyzing the impact of filter strength to filtering result in NLM denoising algorithm, in which the filter strength is adjusted according to the characteristics of current image and the noises in all projection images are suppressed to a similar level. The experimental result shows that the proposed algorithm can accurately estimate the noise level of projection image and markedly improve the slice image quality.
Keywords :
computerised tomography; filtering theory; image denoising; adaptive nonlocal means denoising algorithm; cone-beam computed tomography projection images; filter strength; noise estimation method; slice image quality; sub-block division; Computed tomography; Frequency estimation; Humans; Image coding; Image quality; Multimedia communication; Noise reduction; PSNR; Predictive models; Transform coding; Cone-Beam Computed Tomography; filter strength; noise estimation; non-local means;
Conference_Titel :
Image and Graphics, 2009. ICIG '09. Fifth International Conference on
Conference_Location :
Xi´an, Shanxi
Print_ISBN :
978-1-4244-5237-8
DOI :
10.1109/ICIG.2009.37