Electronic Science and Technology ›› 2019, Vol. 32 ›› Issue (4): 44-48.doi: 10.16180/j.cnki.issn1007-7820.2019.04.010

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An Image Denoising Algorithm Based on Improved Threshold Function Contourlet Domain

WANG Hongchuang,HU Xiaohui,LI Wei   

  1. School of Electronic and Information Engineering, Lanzhou Jiaotong University,Lanzhou 730070, China
  • Received:2018-03-18 Online:2019-04-15 Published:2019-03-27
  • Supported by:
    National Natural Science Foundation of China(61163009);Gansu Science and Technology Project(144NKCA040)

Abstract: Aim

ing at the problem of ringing and pseudo-Gibbs caused by the discontinuity of hard threshold function in the Contourlet domain and the problem of image blur distortion caused by constant value compression in the soft threshold function, a Contourlet domain image denoising method based on improved threshold function was proposed.The improved threshold function introduced the idea of exponential smoothing function method to make it continuous, gradual, deviating and high-order conductibility in the Contourlet domain, which overcame the problems of soft and hard threshold functions. In this method, the BayesShrink adaptive threshold estimation was used in the threshold estimation part, which could accurately determine the threshold size and solved the phenomenon that traditional fixed threshold estimation overkill the transform coefficient. Compared with the traditional denoising methods, the improved image denoising method proposed in this paper had better denoising effect in the objective evaluation criteria including peak signal-to-noise ratio, root mean square error and image enhancement factor.

Key words: image denoising, Contourlet domain, improved threshold function, BayesShrink threshold estimation, peak signal-to-noise ratio, root mean square error, image enhancement factor

CLC Number: 

  • TN911.73