title: A modified undecimated discrete wavelet transform based approach to mammographic image denoising.
abstract: In this work, the authors present an effective denoising method to attempt reducing the noise in mammographic images. The method is based on using hierarchical correlation of the coefficients of discrete stationary wavelet transforms. The features of the proposed technique include iterative use of undecimated multi-directional wavelet transforms at adjacent scales. To validate the proposed method, computer simulations were conducted, followed by its applications to clinical mammograms. Mutual information originating from information theory was used as an evaluation measure for selection of an optimal wavelet basis function. We examined the performance of the proposed method by comparing it with the conventional undecimated discrete wavelet transform (UDWT) method in terms of processing time-consuming and image quality. Our results showed that with the use of the proposed method the computation time can be reduced to approximately 1/10 of the conventional UDWT method consumed. The results of visual assessment indicated that the images processed with the proposed UDWT method showed statistically significant superior image quality over those processed with the conventional UDWT method. Our research results demonstrate the superiority and effectiveness of the proposed approach.
authors.affiliation: Department of Radiological Technology, Graduate School of Health Sciences, Niigata University, 2-746, Asahimachi-dori, Niigata 951-8518, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Matsuyama
authors.forename: Du-Yih
authors.initials: DY
authors.lastname: Tsai
authors.forename: Yongbum
authors.initials: Y
authors.lastname: Lee
authors.forename: Masaki
authors.initials: M
authors.lastname: Tsurumaki
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hsian-Min
authors.initials: HM
authors.lastname: Chen
mesh_terms: D016477:Artifacts; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008327:Mammography / Q000379:methods*; D015203:Reproducibility of Results; D058067:Wavelet Analysis