Study of De-noising Techniques-Applied to Image Restoration

• Main Authors: Lin, Lian-Da, 林良達
• Other Authors: Jung-Hua Wang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/89439193033598738809

碩士 === 國立海洋大學 === 電機工程學系 === 86 === A new algorithm incorporated with standard median filtering is proposed to effectively remove impulsive noise in image processing. This computationally efficient approach first classifies input pixels and then performs median filtering process. Simulation results show that the proposed scheme, regardless of high SNR or low SNR, displays superior mean square error (MSE) over standard median filter. Threshold estimation is a critical step in the Waveshrink method which aims to produce a faithful replica of the uncorrupted input signal. Empirical results show, however, that Waveshrink thresholds (eitherMinimax or Universal) are often too large or too small for achieving optimal results. Alternatively, we present an intuitive approach useful for estimating better thresholds that significantly improve the de-noising performance.