Homomorphic Filtering of Speckle Noise From Computerized Tomography (CT) Images Using Adaptive Centre-Pixel-Weighed Exponential Filter

International Journal of Image Processing

Uche A. Nnolim¹  Ogechukwu N. Iloanusi¹  Martin Chinweokwu Eze¹  Charles C. Osuagwu¹ 

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关键词: Adaptive Filter;    Exponential Filter;    Speckle Noise;    Homomorphic Filtering;    CT Image;    Centre-pixel;    Centre-pixel-weighed.;   

DOI  :  

来源: Computer Science Journals

【 摘 要 】

Adaptive filters are needed to accurately remove noise from noisy images when the variance of noise present varies. Linear filter such as Exponential filter becomes effective in removing speckle noise when homomorphic filtering technique is used. In this paper, an Adaptive Centre- Pixel-Weighed Exponential Filter for removing speckle noise from CT images was developed. The new filter is based on varying the centre-pixel of the filter kernel based on the estimated speckle noise variance present in a noisy CT image. Ten samples of 85x73 CT images corrupted by speckle noise level ranging from 10% to 30% were considered and the new technique gave a reasonably accurate speckle noise filtering performance with an average Peak Signal to Noise Ratio (PSNR) of 70.2839dB compared to 69.0658dB for Wiener filter and 64.3711dB for the Binomial filter. The simulation software used in the paper is Matrix Laboratory (Matlab).

【 授权许可】

Unknown