Linearization of mammograms using parameters derived from noise characteristics.
A method is proposed for converting digitized mammograms to a normalized representation, in which pixel values are linearly related to the logarithm of x-ray exposure. This method is based on a signal dependent noise model. By exploiting this model unknown parameters of the non-linear response of the film-screen system can be estimated from signal dependence of the image noise. The method was applied to a series of 1372 mammograms acquired over a period of 8 years. Sudden changes in estimated parameters corresponded well with the introduction of new film-screen systems.
Karssemeijer
Nico
N
Department of Radiology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands. n.karssemeijer@rad.umcn.nl
Snoeren
Peter R
PR
Zhang
Wei
W
D000465:Algorithms; D016477:Artifacts; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003198:Computer Simulation; D006801:Humans; D016014:Linear Models; D008327:Mammography / Q000379:methods*; D008954:Models, Biological; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013269:Stochastic Processes